Guidelines for Water Reuse (PDF) - epa nepis

Guidelines for Water Reuse (PDF) - epa nepis

EPA/600/R-12/618 | September 2012 2012 Guidelines for Water Reuse Cover Photo Credits: Clockwise from top: greenhouse trial of lettuce grown with ...

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EPA/600/R-12/618 | September 2012

2012

Guidelines for Water Reuse

Cover Photo Credits: Clockwise from top: greenhouse trial of lettuce grown with Washington State Class A reclaimed water, courtesy of Dana Devin Clarke; The E.L. Huie Constructed Wetlands in Clayton County, Georgia, courtesy of Aerial Innovations of Georgia, Inc.; and an aerial view of the Occoquan Reservoir, which is recharged with reclaimed water, courtesy of Roger Snyder, Manassas, Virginia.

EPA/600/R-12/618 September 2012

Guidelines for Water Reuse

U.S. Environmental Protection Agency Office of Wastewater Management Office of Water Washington, D.C.

National Risk Management Research Laboratory Office of Research and Development Cincinnati, Ohio

U.S. Agency for International Development Washington, D.C.

Notice This document was produced by CDM Smith Inc. (CDM Smith) under a Cooperative Research and Development Agreement (CRADA) with the U.S. Environmental Protection Agency (EPA). It has been subjected to EPA’s peer and administrative review and has been approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. The statutes and regulations described in this document may contain legally binding requirements. Neither the summaries of those laws provided here nor the approaches suggested in this document substitute for those statutes or regulations, nor are these guidelines themselves any kind of regulation. This document is intended to be solely informational and does not impose legally binding requirements on EPA; U.S. Agency for International Development (USAID); other U.S. federal agencies, states, local, or tribal governments; or members of the public. Any EPA decisions regarding a particular water reuse project will be made based on the applicable statutes and regulations. EPA will continue to review and update these guidelines as necessary and appropriate.

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Foreword For decades, communities have been reusing valuable reclaimed water to recharge groundwater aquifers, irrigate landscapes and agricultural fields, provide critical stream flows, and provide industries and facilities with an alternative to potable water for a range of uses. While water reuse is not new, population increases and land use changes, combined with changes in the intensity and dynamics of local climatic weather patterns, have exacerbated water supply challenges in many areas of the world. Furthermore, treated wastewater is increasingly being seen as a resource rather than simply ‘waste.’ In this context, water reclamation and reuse have taken on increased importance in the water supply of communities in the United States and around the world in order to achieve efficient resource use, ensure protection of environmental and human health, and improve water management. Strict effluent discharge limits have spurred effective and reliable improvements in treatment technologies. Along with a growing interest in more sustainable water supplies, these improvements have led an increasing number of communities to use reclaimed water as an alternative source to conventional water supplies for a range of applications. In some areas of the United States, water reuse and dual water systems for distribution of reclaimed water for nonpotable uses have become fully integrated into local water supplies. Alternative and efficient water supply options, including reclaimed water, are necessary components of holistic and sustainable water management. As a collaborative effort between EPA and USAID, this document’s primary purpose is to facilitate further development of water reuse by serving as an authoritative reference on water reuse practices. In the United States, water reuse regulation is primarily under the jurisdiction of states, tribal nations, and territories. This document includes an updated overview of regulations or guidelines addressing water reuse that are promulgated by these authorities. Regulations vary from state to state, and some states have yet to develop water reuse guidelines or regulations. This document meets a critical need: it informs and supplements state regulations and guidelines by providing technical information and outlining key implementation considerations. It also presents frameworks should states, tribes, or other authorities decide to develop new regulations or guidelines. This document updates and builds on the 2004 Guidelines for Water Reuse by incorporating information on water reuse that has been developed since the 2004 document was issued. This document includes updated discussion of regional variations of water reuse in the United States, advances in wastewater treatment technologies relevant to reuse, best practices for involving communities in planning projects, international water reuse practices, and factors that will allow expansion of safe and sustainable water reuse throughout the world. The 2012 guidelines also provide more than 100 new case studies from around the world that highlight how reuse applications can and do work in the real world. Over 300 reuse experts, practitioners, and regulators contributed text, technical reviews, regulatory information, and case studies. This breadth of experience provides a broad and blended perspective of the scientific, technical, and programmatic principles for implementing decisions about water reuse in a safe and sustainable manner. Nancy Stoner Acting Assistant Administrator Office of Water U.S. EPA

Eric Postel Assistant Administrator Bureau for Economic Growth, Education & Environment USAID

Lek Kadeli Acting Assistant Administrator Office of Research & Development U.S. EPA

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Updating the Guidelines The Guidelines for Water Reuse debuted in 1980 and was updated in 1992 and 2004. EPA contracted with CDM Smith through a CRADA to update the EPA guidelines for this 2012 release. Building on the work of previous versions, the CDM Smith project management team has involved a wide range of stakeholders in the development process. Beginning in 2009, EPA, USAID, and CDM Smith began facilitating workshops and informational sessions at water events and conferences around the world to solicit feedback on what information should be repeated, updated, added, or removed from the 2004 document. In addition, a committee of national and international experts in the field of water reclamation and related subjects was established to approve the document outline, develop new text and case studies, and review interim drafts of the document. Ten stakeholder consultations were carried out in 2009 to 2011. (Unless otherwise noted, the consultations were held in the United States.) The consultations included: 

September and October 2009: Stakeholder workshops at the Annual WateReuse Symposium in Seattle, Wash., and Water Environment Federation Technical Exhibition and Conference (WEFTEC) in Orlando, Fla., were conducted to collect feedback on the format and scope of the update.



November 2010: Brainstorming sessions at the American Water Works Association (AWWA) Water Quality Technology conference in Savannah, Ga., were held to identify major focus areas in the 2004 document and to identify potential authors and contributors.



March, July, and September 2011: The International Water Association (IWA) Efficient 2011 conference in Jordan and the Singapore International Water Week (SIWW) in Singapore were used to collect input on international water reuse practices that encompass a range of treatment technologies, market-based mechanisms for implementation of reuse, and strategies for reducing water reuse-related health risks in developing countries. A status report was presented at the IWA International Conference on Water Reclamation and Reuse in Barcelona, Spain.



January to October 2011: Status reports were presented at the New England Water Environment Association conference in Boston, Mass.; the WateReuse California conference in Dana Point, Calif.; the Annual WateReuse Symposium in Phoenix, Ariz.; and in a special session at the WEFTEC in Los Angeles, Calif.

The workshops held in Jordan, Singapore, and Spain provided an opportunity for input from a diverse group of international participants. Professionals from the private sector also attended these events, as did representatives from government and state agencies, universities, and nonprofit water-advocacy organizations. Nongovernmental organizations, including the World Bank, World Health Organization (WHO), and International Water Management Institute (IWMI), were also represented. The stakeholder input process identified a number of themes to update or emphasize in the updated guidelines, including:

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The role of reuse in integrated water resources management



Energy use and sustainability associated with water reuse



Agricultural reuse



Wetlands polishing and stream augmentation



Expanding opportunities for industrial reuse

2012 Guidelines for Water Reuse



Groundwater augmentation and managed aquifer recharge



Individual on-site and graywater reuse systems



New information on direct and indirect potable reuse practices



International trends in water reuse

In addition to the stakeholder input, the final document was researched, written, and reviewed by more than 300 experts in the field, including authors who contributed to case studies or chapters and reviewers. The contributors included participants from other consulting firms, state and federal agencies, local water and wastewater authorities, and academic institutions. The project management team compiled and integrated the contributions. The formal review process included a two-stage technical review. The first stage of review was conducted by additional technical experts who were not involved in writing the document, who identified gaps or edits for further development. The project management team edited the text based on these recommendations and wrote or solicited additional text. The second stage of review was conducted by the peer review team; a group of reviewers who are experts in various areas of water reuse. The peer review team provided a written technical review and inperson comments during a meeting in June 2012. The project management team carefully evaluated and documented all technical comments/recommendations and the decision-making regarding the incorporation of the recommendations into the document. The final draft and review record was presented to EPA and USAID for final approval in August 2012.

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Table of Contents Chapter 1 Introduction .......................................................................................................1-1 1.1 Objectives of the Guidelines ............................................................................................ 1-1 1.2 Overview of the Guidelines .............................................................................................. 1-2 1.3 Guidelines Terminology ................................................................................................... 1-2 1.4 Motivation for Reuse ........................................................................................................ 1-5 1.4.1 Urbanization and Water Scarcity ........................................................................... 1-5 1.4.2 Water-Energy Nexus .............................................................................................. 1-5 1.4.3 Environmental Protection ....................................................................................... 1-6 1.5 "Fit for Purpose" ............................................................................................................... 1-7 1.6 References ....................................................................................................................... 1-8

Chapter 2 Planning and Management Considerations.....................................................2-1 2.1 Integrated Water Management ........................................................................................ 2-1 2.2 Planning Municipal Reclaimed Water Systems ............................................................... 2-3 2.2.1 Identifying Users and Types of Reuse Demands .................................................. 2-4 2.2.2 Land Use and Local Reuse Policy ......................................................................... 2-4 2.2.3 Distribution System Considerations ....................................................................... 2-6 2.2.3.1 Distribution System Pumping and Piping .................................................... 2-7 2.2.3.2 Reclaimed Water Appurtenances ............................................................... 2-8 2.2.3.3 On-Site Construction Considerations.......................................................... 2-9 2.2.4 Institutional Considerations .................................................................................. 2-10 2.3 Managing Reclaimed Water Supplies ............................................................................ 2-11 2.3.1 Operational Storage ............................................................................................. 2-12 2.3.2 Surface Water Storage and Augmentation .......................................................... 2-13 2.3.3 Managed Aquifer Recharge ................................................................................. 2-14 2.3.3.1 Water Quality Considerations ................................................................... 2-15 2.3.3.2 Surface Spreading .................................................................................... 2-16 2.3.3.3 Injection Wells ........................................................................................... 2-17 2.3.3.4 Recovery of Reclaimed Water through ASR ............................................ 2-20 2.3.3.5 Supplementing Reclaimed Water Supplies .............................................. 2-22 2.3.4 Operating a Reclaimed Water System ................................................................. 2-23 2.3.4.1 Quality Control in Production of Reclaimed Water ................................... 2-23 2.3.4.2 Distribution System Safeguards for Public Health Protection in Nonpotable Reuse ............................................... 2-23 2.3.4.3 Preventing Improper Use and Backflow ................................................... 2-25 2.3.4.4 Maintenance.............................................................................................. 2-25 2.3.4.5 Quality Assurance: Monitoring Programs ................................................. 2-26 2.3.4.6 Response to Failures ................................................................................ 2-27 2.3.5 Lessons Learned from Large, Medium, and Small Systems ............................... 2-28 2.4 Water Supply Conservation and Alternative Water Resources ..................................... 2-31 2.4.1 Water Conservation ............................................................................................. 2-31 2.4.2 Alternative Water Resources ............................................................................... 2-32 2.4.2.1 Individual On-site Reuse Systems and Graywater Reuse ........................ 2-32 2.4.2.2 LEED-Driven On-site Treatment ............................................................... 2-35 2.4.2.3 Stormwater Harvesting and Use ............................................................... 2-37 2.5 Environmental Considerations ....................................................................................... 2-37

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2.5.1 Land Use Impacts ................................................................................................ 2-38 2.5.2 Water Quantity Impacts........................................................................................ 2-38 2.5.3 Water Quality Impacts .......................................................................................... 2-39 2.6 References ..................................................................................................................... 2-40

Chapter 3 Types of Reuse Applications ............................................................................3-1 3.1 Urban Reuse .................................................................................................................... 3-2 3.1.1 Golf Courses and Recreational Field Irrigation ...................................................... 3-2 3.2 Agricultural Reuse ............................................................................................................ 3-4 3.2.1 Agricultural Reuse Standards ................................................................................ 3-6 3.2.2 Agricultural Reuse Water Quality ........................................................................... 3-6 3.2.2.1 Salinity and Chlorine Residual .................................................................... 3-8 3.2.2.2 Trace Elements and Nutrients .................................................................... 3-8 3.2.2.3 Operational Considerations for Agricultural Reuse................................... 3-10 3.2.3 Irrigation of Food Crops ....................................................................................... 3-10 3.2.4 Irrigation of Processed Food Crops and Non-Food Crops .................................. 3-11 3.2.5 Reclaimed Water for Livestock Watering ............................................................. 3-13 3.3 Impoundments................................................................................................................ 3-13 3.3.1 Recreational and Landscape Impoundments ...................................................... 3-14 3.3.2 Snowmaking ......................................................................................................... 3-14 3.4 Environmental Reuse ..................................................................................................... 3-16 3.4.1 Wetlands .............................................................................................................. 3-16 3.4.1.1 Wildlife Habitat and Fisheries ................................................................... 3-18 3.3.1.2 Flood Attenuation and Hydrologic Balance ............................................... 3-18 3.3.1.3 Recreation and Educational Benefits ........................................................ 3-18 3.4.2 River or Stream Flow Augmentation .................................................................... 3-19 3.4.3 Ecological Impacts of Environmental Reuse........................................................ 3-19 3.5 Industrial Reuse ............................................................................................................. 3-20 3.5.1 Cooling Towers .................................................................................................... 3-20 3.5.2 Boiler Water Makeup............................................................................................ 3-22 3.5.3 Produced Water from Oil and Natural Gas Production ........................................ 3-23 3.5.4 High-Technology Water Reuse ............................................................................ 3-24 3.5.5 Prepared Food Manufacturing ............................................................................. 3-24 3.6 Groundwater Recharge – Nonpotable Reuse ................................................................ 3-26 3.7 Potable Reuse ................................................................................................................ 3-26 3.7.1 Planned Indirect Potable Reuse (IPR) ................................................................. 3-28 3.7.2 Direct Potable Reuse (DPR) ................................................................................ 3-30 3.7.2.1 Planning for DPR ...................................................................................... 3-30 3.7.2.2 Future Research Needs ............................................................................ 3-32 3.8 References ..................................................................................................................... 3-33

Chapter 4 State Regulatory Programs for Water Reuse ..................................................4-1 4.1 Reuse Program Framework ............................................................................................. 4-1 4.2 Regulatory Framework ..................................................................................................... 4-1 4.3 Relationship of State Regulatory Programs for Water Reuse to Other Regulatory Programs ............................................................................................. 4-1 4.3.1 Water Rights .......................................................................................................... 4-4 4.3.2 Water Supply and Use Regulations ....................................................................... 4-5 4.3.3 Wastewater Regulations and Related Environmental Regulations ....................... 4-5

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4.3.4 Drinking Water Source Protection .......................................................................... 4-6 4.3.5 Land Use ................................................................................................................ 4-6 4.4 Suggested Regulatory Guidelines for Water Reuse Categories ...................................... 4-6 4.4.1 Water Reuse Categories ........................................................................................ 4-7 4.4.2 Suggested Regulatory Guidelines ......................................................................... 4-7 4.4.3 Rationale for Suggested Regulatory Guidelines .................................................... 4-7 4.4.3.1 Combining Treatment Process Requirements with Water Quality Limits .................................................................................. 4-12 4.4.3.2 Water Quality Requirements for Disinfection ............................................ 4-12 4.4.3.3 Indicators of Disinfection ........................................................................... 4-13 4.4.3.4 Water Quality Requirements for Suspended and Particulate Matter ........ 4-14 4.4.3.5 Water Quality Requirements for Organic Matter ....................................... 4-14 4.4.3.6 Setback Distances .................................................................................... 4-14 4.4.3.7 Specific Considerations for IPR ................................................................ 4-15 4.4.4 Additional Requirements ...................................................................................... 4-16 4.4.4.1 Reclaimed Water Monitoring Requirements ............................................. 4-16 4.4.4.2 Treatment Facility Reliability ..................................................................... 4-16 4.4.4.3 Reclaimed Water Storage ......................................................................... 4-17 4.5 Inventory of State Regulations and Guidelines .............................................................. 4-17 4.5.1 Overall Summary of States’ Regulations ............................................................. 4-17 4.5.1.1 Case-By-Case Considerations .................................................................. 4-17 4.5.1.2 Reuse or Treatment and Disposal Perspective ........................................ 4-21 4.5.2 Summary of Ten States’ Reclaimed Water Quality and Treatment Requirements ....................................................................... 4-22 4.5.2.1 Urban Reuse – Unrestricted ..................................................................... 4-23 4.5.2.2 Urban Reuse – Restricted ......................................................................... 4-23 4.5.2.3 Agricultural Reuse – Food Crops .............................................................. 4-23 4.5.2.4 Agricultural Reuse – Processed Food Crops and Non-food Crops .......... 4-24 4.5.2.5 Impoundments – Unrestricted ................................................................... 4-24 4.5.2.6 Impoundments – Restricted ...................................................................... 4-24 4.5.2.7 Environmental Reuse ................................................................................ 4-24 4.5.2.8 Industrial Reuse ........................................................................................ 4-24 4.5.2.9 Groundwater Recharge – Nonpotable Reuse ........................................... 4-25 4.5.2.10 Indirect Potable Reuse (IPR) .................................................................. 4-25 4.6 References ..................................................................................................................... 4-37

Chapter 5 Regional Variations in Water Reuse.................................................................5-1 5.1 Overview of Water Use and Regional Reuse Considerations ......................................... 5-1 5.1.1 National Water Use ................................................................................................ 5-1 5.1.2 Examples of Reuse in the United States ............................................................... 5-2 5.2 Regional Considerations .................................................................................................. 5-2 5.2.1 Northeast ................................................................................................................ 5-6 5.2.1.1 Population and Land Use ............................................................................ 5-9 5.2.1.2 Precipitation and Climate ............................................................................ 5-9 5.2.1.3 Water Use by Sector ................................................................................... 5-9 5.2.1.4 States’ and Territories’ Regulatory Context .............................................. 5-10 5.2.1.5 Context and Drivers of Water Reuse ........................................................ 5-11 5.2.2 Mid-Atlantic .......................................................................................................... 5-12 5.2.2.1 Population and Land Use .......................................................................... 5-12 5.2.2.2 Precipitation and Climate .......................................................................... 5-13

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5.2.2.3 Water Use by Sector ................................................................................. 5-13 5.2.2.4. States’ Regulatory Context ...................................................................... 5-13 5.2.2.5 Context and Drivers of Water Reuse ........................................................ 5-14 5.2.3 Southeast ............................................................................................................. 5-15 5.2.3.1 Population and Land Use .......................................................................... 5-15 5.2.3.2 Precipitation and Climate .......................................................................... 5-16 5.2.3.3 Water Use by Sector ................................................................................. 5-16 5.2.3.4. States’ Regulatory Context ...................................................................... 5-18 5.2.3.5 Context and Drivers of Water Reuse ........................................................ 5-19 5.2.4 Midwest and Great Lakes .................................................................................... 5-23 5.2.4.1 Population and Land Use .......................................................................... 5-23 5.2.4.2 Precipitation and Climate .......................................................................... 5-24 5.2.4.3 Water Use by Sector ................................................................................. 5-24 5.2.4.4. States’ Regulatory Context ...................................................................... 5-25 5.2.4.5 Context and Drivers of Water Reuse ........................................................ 5-26 5.2.5 South Central ....................................................................................................... 5-29 5.2.5.1 Population and Land Use .......................................................................... 5-29 5.2.5.2 Precipitation and Climate .......................................................................... 5-29 5.2.5.3 Water Use by Sector ................................................................................. 5-30 5.2.5.4. States’ Regulatory Context ...................................................................... 5-30 5.2.5.5 Context and Drivers of Water Reuse ........................................................ 5-31 5.2.6 Mountains and Plains ........................................................................................... 5-35 5.2.6.1 Population and Land Use .......................................................................... 5-35 5.2.6.2 Precipitation .............................................................................................. 5-35 5.2.6.3 Water Use by Sector ................................................................................. 5-35 5.2.6.4. States’ Regulatory Context ...................................................................... 5-36 5.2.6.5 Context and Drivers of Water Reuse ........................................................ 5-36 5.2.7 Pacific Southwest ................................................................................................. 5-37 5.2.7.1 Population and Land Use .......................................................................... 5-37 5.2.7.2 Precipitation and Climate .......................................................................... 5-38 5.2.7.3 Water Use by Sector ................................................................................. 5-39 5.2.7.4. States’ Regulatory Context ...................................................................... 5-39 5.2.7.5 Context and Drivers of Water Reuse ........................................................ 5-41 5.2.8 Pacific Northwest ................................................................................................. 5-44 5.2.8.1 Population and Land Use .......................................................................... 5-45 5.2.8.2 Precipitation and Climate .......................................................................... 5-45 5.2.8.3 Water Use by Sector ................................................................................. 5-46 5.2.8.4. States’ Regulatory Context ...................................................................... 5-46 5.2.8.5 Context and Drivers of Water Reuse ........................................................ 5-47 5.3 References ..................................................................................................................... 5-48

Chapter 6 Treatment Technologies for Protecting Public and Environmental Health ...6-1 6.1 Public Health Considerations ........................................................................................... 6-2 6.1.1 What is the Intended Use of the Reclaimed Water? .............................................. 6-2 6.1.2 What Constituents are Present in a Wastewater Source, and What Level of Treatment is Applicable for Reducing Constituents to Levels that Achieve the Desired Reclaimed Water Quality? ................................ 6-3 6.1.3 Which Sampling/Monitoring Protocols Are Required to Ensure that Water Quality Objectives Are Being Met? ............................................................ 6-3 6.2 Wastewater Constituents and Assessing Their Risks ..................................................... 6-4

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6.2.1 Microorganisms in Wastewater .............................................................................. 6-4 6.2.1.1 Protozoa and Helminths .............................................................................. 6-6 6.2.1.2 Bacteria ....................................................................................................... 6-6 6.2.1.3 Viruses ........................................................................................................ 6-7 6.2.1.4 Aerosols ...................................................................................................... 6-7 6.2.1.5 Indicator Organisms .................................................................................... 6-7 6.2.1.6 Removal of Microorganisms ....................................................................... 6-8 6.2.1.7 Risk Assessment of Microbial Contaminants .............................................. 6-9 6.2.2 Chemicals in Wastewater..................................................................................... 6-10 6.2.2.1 Inorganic Chemicals ................................................................................. 6-10 6.2.2.2 Organics .................................................................................................... 6-11 6.2.2.3 Trace Chemical Constituents .................................................................... 6-12 6.3 Regulatory Approaches to Establishing Treatment Goals for Reclaimed Water ........... 6-17 6.3.1 Microbial Inactivation............................................................................................ 6-18 6.3.2 Constituents of Emerging Concern ...................................................................... 6-19 6.3.2.1 Example of California’s Regulatory Approach to CECs ............................ 6-20 6.3.2.2 Example of Australia’s Regulatory Approach to Pharmaceuticals ............ 6-21 6.4 Wastewater Treatment for Reuse .................................................................................. 6-21 6.4.1 Source Control ..................................................................................................... 6-22 6.4.2 Filtration ............................................................................................................... 6-23 6.4.2.1 Depth Filtration .......................................................................................... 6-24 6.4.2.2 Surface Filtration ....................................................................................... 6-24 6.4.2.3 Membrane Filtration .................................................................................. 6-24 6.4.2.4 Biofiltration ................................................................................................ 6-25 6.4.3 Disinfection ........................................................................................................... 6-26 6.4.3.1 Chlorination ............................................................................................... 6-27 6.4.3.2 Ultraviolet Disinfection .............................................................................. 6-28 6.4.3.3 Ozone ........................................................................................................ 6-30 6.4.3.4 Pasteurization ........................................................................................... 6-31 6.4.3.5 Ferrate ....................................................................................................... 6-32 6.4.4 Advanced Oxidation ............................................................................................. 6-32 6.4.5 Natural Systems ................................................................................................... 6-34 6.4.5.1 Treatment Mechanisms in Natural Systems ............................................. 6-34 6.4.5.2 Wetlands ................................................................................................... 6-36 6.4.5.3 Soil Aquifer Treatment Systems ............................................................... 6-37 6.4.6 Monitoring for Treatment Performance ................................................................ 6-37 6.4.7 Energy Considerations in Reclaimed Water Treatment....................................... 6-38 6.5 References ..................................................................................................................... 6-39

Chapter 7 Funding Water Reuse Systems ........................................................................7-1 7.1 Integrating Reclaimed Water into a Water Resource Portfolio ........................................ 7-1 7.2 Internal and Debt Funding Alternatives ............................................................................ 7-2 7.2.1 State and Federal Financial Assistance................................................................. 7-2 7.2.1.1 Federal Funding Sources ............................................................................ 7-3 7.2.1.2 State, Regional, and Local Grant and Loan Support .................................. 7-4 7.3 Phasing and Participation Incentives ............................................................................... 7-5 7.4 Sample Rate and Fee Structures ..................................................................................... 7-6 7.4.1 Service Fees .......................................................................................................... 7-6 7.4.2 Special Assessments ............................................................................................. 7-8 7.4.3 Impact Fees ........................................................................................................... 7-8

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7.4.4 Fixed Monthly Fee .................................................................................................. 7-8 7.4.5 Volumetric Rates .................................................................................................... 7-8 7.5 Developing Rates ............................................................................................................. 7-8 7.5.1 Market Rates Driven by Potable Water................................................................ 7-10 7.5.2 Service Agreements Based on Take or Pay Charges ......................................... 7-11 7.5.3 Reuse Systems for New Development ................................................................ 7-12 7.5.4 Connection Fees for Wastewater Treatment versus Distribution ........................ 7-12 7.6 References ..................................................................................................................... 7-13

Chapter 8 Public Outreach, Participation, and Consultation ...........................................8-1 8.1 Defining Public Involvement ............................................................................................. 8-1 8.1.1 Public Opinion Shift: Reuse as an Option in the Water Management Toolbox ..... 8-1 8.1.2 Framing the Benefits .............................................................................................. 8-2 8.2 Why Public Participation is Critical ................................................................................... 8-3 8.2.1 Project Success ..................................................................................................... 8-3 8.2.2 The Importance of an Informed Constituency ........................................................ 8-3 8.2.3 Building Trust ......................................................................................................... 8-3 8.3 Identifying the “Public” ...................................................................................................... 8-4 8.4 Steps to Successful Public Participation .......................................................................... 8-4 8.4.1 Situational Analysis ................................................................................................ 8-5 8.4.1.1 Environmental Justice ................................................................................. 8-6 8.4.2 Levels of Involvement ............................................................................................ 8-7 8.4.3 Communication Plan .............................................................................................. 8-7 8.4.3.1 The Role of Information in Changing Opinion ............................................. 8-7 8.4.3.2 Words Count ............................................................................................... 8-8 8.4.3.3 Slogans and Branding ............................................................................... 8-11 8.4.3.4 Reclaimed Water Signage ........................................................................ 8-11 8.4.4 Public Understanding ........................................................................................... 8-12 8.4.4.1 Perception of Risk ..................................................................................... 8-12 8.4.4.2 Trusted Information Sources ..................................................................... 8-12 8.4.5 Community Leaders ............................................................................................. 8-13 8.4.6 Independent Experts ............................................................................................ 8-13 8.4.6.1 Advisory Groups........................................................................................ 8-13 8.4.6.2 Independent Advisory Panels ................................................................... 8-14 8.4.6.3 Independent Monitoring and Certification ................................................. 8-14 8.4.7 Media Outreach .................................................................................................... 8-15 8.4.7.1 New Media Outreach Methods – Social Networking ................................ 8-15 8.4.8 Involving Employees ............................................................................................ 8-16 8.4.9 Direct Stakeholder Engagement .......................................................................... 8-16 8.4.9.1 Dialogue with Stakeholders ...................................................................... 8-16 8.4.9.2 Addressing Opposition .............................................................................. 8-16 8.5 Variations in Public Outreach ......................................................................................... 8-17 8.6 References ..................................................................................................................... 8-18

Chapter 9 Global Experiences in Water Reuse .................................................................9-1 9.1 Introduction....................................................................................................................... 9-1 9.1.1 Defining the Resources Context ............................................................................ 9-1 9.1.2 Planned Water Reuse and Wastewater Use ......................................................... 9-1 9.1.3 International Case Studies ..................................................................................... 9-2

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9.2 Overview of Global Water Reuse ..................................................................................... 9-6 9.2.1 Types of Water Reuse ........................................................................................... 9-6 9.2.1.1 Agricultural Applications .............................................................................. 9-6 9.2.1.2 Urban and Industrial Applications ............................................................... 9-6 9.2.1.3 Aquifer Recharge ........................................................................................ 9-7 9.2.2 Magnitude of Global Water Reuse ......................................................................... 9-7 9.3 Opportunities and Challenges for Expanding the Scale of Global Water Reuse ............. 9-8 9.3.1 Global Drivers ........................................................................................................ 9-9 9.3.2 Regional Variation in Water Reuse ...................................................................... 9-10 9.3.3 Global Barriers to Expanding Planned Reuse ..................................................... 9-11 9.3.3.1 Institutional Barriers .................................................................................. 9-11 9.3.3.2 Public Perception/Educational Barriers .................................................... 9-12 9.3.3.3 Economic Barriers ..................................................................................... 9-12 9.3.3.4 Organizational Barriers ............................................................................. 9-12 9.3.4 Benefits of Expanding the Scale of Water Reuse ................................................ 9-13 9.4 Improving Safe and Sustainable Water Reuse for Optimal Benefits ............................. 9-13 9.4.1 Reducing Risks of Unplanned Reuse: The WHO Approach................................ 9-13 9.4.2 Expanding and Optimizing Planned Water Reuse ............................................... 9-16 9.5 Factors Enabling Successful Implementation of Safe and Sustainable Water Reuse ........................................................................................................ 9-20 9.6 Global Lessons Learned About Water Reuse................................................................ 9-21 9.7 References ..................................................................................................................... 9-22

Appendix A Funding for Water Reuse Research ............................................................. A-1 Appendix B Inventory of Recent Water Reuse Research Projects and Reports ........... B-1 Appendix C Websites of U.S. State Regulations and Guidance on Water Reuse ......... C-1 Appendix D U.S. Case Studies .......................................................................................... D-1 Appendix E International Case Studies and International Regulations ......................... E-1 Appendix F List of Case Studies in 2004 Guidelines for Water Reuse .......................... F-1 Appendix G Abbreviations ................................................................................................G-1

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List of Tables Chapter 1 Table 1-1 Organization of 2012 Guidelines for Water Reuse ................................................ 1-3 Table 1-2 Categories of water reuse applications.................................................................. 1-4

Chapter 2 Table 2-1 Common institutional arrangements for water reuse ........................................... 2-10 Table 2-2 Comparison of vadose zone and direct injection recharge wells ........................ 2-18 Table 2-3 Operational status and source water treatment for reclaimed water ASR projects ................................................................................................................ 2-22 Table 2-4 Quality monitoring requirements in Texas ........................................................... 2-26 Table 2-5 Summary of NSF Standard 350 Effluent Criteria for individual classifications .... 2-34 Table 2-6 Summary of ANSI/NSF Standard 350-1 for subsurface discharges ................... 2-34

Chapter 3 Table 3-1 Distribution of reclaimed water in California and Florida ....................................... 3-2 Table 3-2 Interpretation of reclaimed water quality ................................................................ 3-3 Table 3-3 Nationwide reuse summaries of reclaimed water use in agricultural irrigation ...... 3-5 Table 3-4 Guidelines for interpretation of water quality for irrigation ..................................... 3-7 Table 3-5 Recommended water quality criteria for irrigation ................................................ 3-9 Table 3-6 Examples of global water quality standards for non-food crop irrigation ............. 3-13 Table 3-7 Guidelines for concentrations of substances in livestock drinking water ............. 3-13 Table 3-8 Recommended boiler water limits ........................................................................ 3-22 Table 3-9 Overview of selected planned indirect and direct potable reuse installations worldwide (not intended to be a complete survey) .............................................. 3-28

Chapter 4 Table 4-1 Key elements of a water reuse program ................................................................ 4-2 Table 4-2 Fundamental components of a water reuse regulatory framework for states ....... 4-3 Table 4-3 Water reuse categories and number of states with rules, regulations or guidelines addressing these reuse categories ...................................................... 4-8 Table 4-4 Suggested guidelines for water reuse ................................................................... 4-9 Table 4-5 Summary of State and U.S. Territory reuse regulations and guidelines ............. 4-18 Table 4-6 Abbreviations of terms for state reuse rules descriptions .................................... 4-23 Table 4-7 Urban reuse – unrestricted .................................................................................. 4-26 Table 4-8 Urban reuse – restricted ...................................................................................... 4-27 Table 4-9 Agricultural reuse - food crops ............................................................................. 4-28 Table 4-10 Agricultural reuse – non-food crops and processed food crops (where permitted) ............................................................................................................. 4-29 Table 4-11 Impoundments – unrestricted ............................................................................ 4-30 Table 4-12 Impoundments – restricted ................................................................................ 4-31 Table 4-13 Environmental reuse .......................................................................................... 4-32 Table 4-14 Industrial reuse .................................................................................................. 4-33 Table 4-15 Groundwater recharge - nonpotable reuse ........................................................ 4-34 Table 4-16 Indirect potable reuse (IPR) ............................................................................... 4-35

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Chapter 5 Table 5-1 Percent change in resident population in each region during the periods 1990-2000, 2000-2010, and 1990-2010 ................................................... 5-7

Chapter 6 Table 6-1 Types of reuse appropriate for increasing levels of treatment............................... 6-2 Table 6-2 Infectious agents potentially present in untreated (raw) wastewater ..................... 6-5 Table 6-3 Indicative log removals of indicator microorganisms and enteric pathogens during various stages of wastewater treatment ................................... 6-9 Table 6-4 Categories of trace chemical constituents (natural and synthetic) potentially detectable in reclaimed water and illustrative example chemicals ..... 6-13 Table 6-5 Indicative percent removals of organic chemicals during various stages of wastewater treatment ........................................................................... 6-16 Table 6-6 Summary of filter type characteristics .................................................................. 6-25 Table 6-7 California and Florida disinfection treatment-based standards for tertiary recycled water and high level disinfection .......................................... 6-27 Table 6-8 Electrochemical oxidation potential (EOP) for several disinfectants ................... 6-33

Chapter 7 Table 7-1 Comparison of reclaimed water rates .................................................................... 7-7 Table 7-2 Utility distribution of the reclaimed water rate as a percent of the potable water rate for single-family homes in Florida .......................................... 7-11

Chapter 8 Table 8-1 Focus group participant responses–most trusted sources .................................. 8-13

Chapter 9 Table 9-1 Global domestic wastewater generated and treated ............................................. 9-7 Table 9-2 Projected reuse capacity in selected countries ..................................................... 9-8 Table 9-3 Percent of urban populations connected to piped sewer systems in 2003-2006 ............................................................................................................ 9-11 Table 9-4 Selected health-protection measures and associated pathogen reductions for wastewater reuse in agriculture ...................................................................... 9-15 Table 9-5 Challenges and solutions for reuse standards development and implementation..................................................................................................... 9-17

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List of Figures Chapter 1 Figure 1-1 The 2004 EPA Guidelines for Water Reuse has had global influence ................. 1-1 Figure 1-2 Purple pipe is widely used for reclaimed water distribution systems ................... 1-6 Figure 1-3 Treatment technologies are available to achieve any desired level of water quality............................................................................................. 1-7

Chapter 2 Figure 2-1 Traditional versus Integrated Water Management ............................................... 2-1 Figure 2-2 36-inch CSC 301 purple mortar pipe, San Antonio Water System....................... 2-7 Figure 2-3 Appropriate separation of potable, reclaimed water, and sanitary sewer pipes ... 2-8 Figure 2-4 Purple snap-on reclaimed water identification cap ............................................... 2-9 Figure 2-5 Commonly used methods in managed aquifer recharge .................................... 2-15 Figure 2-6 Sample decision tree for selection of groundwater recharge method ................ 2-15 Figure 2-7 Typical sign complying with FDEP signage requirements.................................. 2-24 Figure 2-8 Reclaimed water pumping station, San Antonio, Texas ..................................... 2-25 Figure 2-9 Upper Occoquan schematic ............................................................................... 2-29

Chapter 3 Figure 3-1 Reclaimed water use in the United States............................................................ 3-1 Figure 3-2 Nationwide reuse summaries of reclaimed water use in agricultural irrigation ... 3-5 Figure 3-3 Monterey County vegetable fields irrigated with disinfected tertiary recycled water ................................................................................................................. 3-12 Figure 3-4 Alfalfa irrigated with secondary effluent, Wadi Mousa (near Petra), Jordan ...... 3-12 Figure 3-5 Large hyperbolic cooling towers ......................................................................... 3-21 Figure 3-6 Estimates of produced water by state ................................................................ 3-23 Figure 3-7 Planned IPR scenarios and examples ................................................................ 3-29 Figure 3-8 Planned DPR and specific examples of implementation .................................... 3-31

Chapter 5 Figure 5-1 Freshwater use by category in the United States ................................................. 5-1 Figure 5-2 Geographic display of United States reuse case studies categorized by application ............................................................................................................ 5-3 Figure 5-3 Percent change in population (2000-2010) and developed land (1997-2007) in the Northeast Region, compared to the United States ................. 5-9 Figure 5-4 Average monthly precipitation (1971-2000) for states in the Northeast Region... 5-9 Figure 5-5 Freshwater use by sector for the Northeast region .............................................. 5-9 Figure 5-6 Change in population (2000-2010) and developed land (1997-2007) in the Mid-Atlantic region, compared to the United States. ........................................... 5-12 Figure 5-7 Average monthly precipitation in the Mid-Atlantic region ................................... 5-13 Figure 5-8 Freshwater use by sector for the Mid-Atlantic region ......................................... 5-13 Figure 5-9 Change in population (2000-2010) and developed land (1997-2007) in the Southeast region, compared to the United States. .............................................. 5-16 Figure 5-10 Average monthly precipitation in the Southeast region .................................... 5-16 Figure 5-11 Freshwater use by sector for the Southeast region .......................................... 5-17 Figure 5-12 Water reuse in Florida by type ......................................................................... 5-20

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Figure 5-13 Map of per capita reuse flow by county in Florida ............................................ 5-21 Figure 5-14 Cary, N.C., bulk fill station allows approved contractors, landscapers, and town staff to use reclaimed water .................................................................... 5-22 Figure 5-15 Change in population (2000-2010) and developed land (1997-2007) in the Midwest and Great Lakes Regions, compared to the United States. .............. 5-24 Figure 5-16 Average monthly precipitation in the Midwest .................................................. 5-24 Figure 5-17 Freshwater use by sector for the Midwest and Great Lakes Regions .............. 5-24 Figure 5-18 Water use in Minnesota, 2007 .......................................................................... 5-25 Figure 5-19 Water use in Minnesota by source, 2007 ......................................................... 5-25 Figure 5-20 The SMSC WRF and wetlands ......................................................................... 5-27 Figure 5-21 Mankato Water Reclamation Facility ................................................................ 5-28 Figure 5-22 Change in population (2000-2010) and developed land (1997-2007) in the South Central Region, compared to the United States. .................................. 5-29 Figure 5-23 Average monthly precipitation in the South Central region .............................. 5-30 Figure 5-24 Freshwater use by sector for the South Central region .................................... 5-30 Figure 5-25 Water consumption in El Paso, Texas.............................................................. 5-34 Figure 5-26 Wastewater flows in El Paso, Texas ................................................................ 5-34 Figure 5-27 Wastewater influent strength, BOD 5 ................................................................. 5-34 Figure 5-28 Wastewater influent strength, NH3-N ............................................................... 5-34 Figure 5-29 Wastewater influent strength, TSS ................................................................... 5-34 Figure 5-30 Change in population (2000-2010) and developed land (1997-2007) in the Mountain and Plains region, compared to the United States ................ 5-35 Figure 5-31 Average monthly precipitation in the Mountains and Plains Regions .............. 5-35 Figure 5-32 Freshwater use by sector for the Mountains and Plains regions ..................... 5-36 Figure 5-33 Change in population (2000-2010) and developed land (1997-2007) Pacific Southwest Region, compared to the United States ............................. 5-38 Figure 5-34 Average monthly precipitation in the Pacific Southwest region ........................ 5-38 Figure 5-35 Freshwater use by sector for the Pacific Southwest Region ............................ 5-39 Figure 5-36 2010 Reclaimed water use in Tucson, Ariz. ..................................................... 5-42 Figure 5-37 Uses of recycled water in California ................................................................. 5-42 Figure 5-38 Change in population (2000-2010) and developed land (1997-2007) in the Pacific Northwest region, compared to the United States. .................... 5-45 Figure 5-39 Average monthly precipitation in the Pacific Northwest region ........................ 5-45 Figure 5-40 Freshwater use by sector for the Pacific Northwest region .............................. 5-46

Chapter 6 Figure 6-1 Potable reuse treatment scenarios ....................................................................... 6-1 Figure 6-2 Pasteurization demonstration system in Ventura, Calif. ..................................... 6-31 Figure 6-3 Example WRF treatment train that includes UV/H2O2 AOP ............................... 6-32

Chapter 8 Figure 8-1 Survey results from San Diego: opinion about using advanced treated recycled water as an addition to drinking water supply ........................... 8-2 Figure 8-2 Focus group participant responses: before and after viewing information ........... 8-8 Figure 8-3 Water reclamation terms most used by the water industry are the least reassuring to the public ..................................................... 8-9 Figure 8-4 Focus group participants preferred “direct potable use” over “business as usual,” “blended reservoir,” or “upstream discharge” IPR options ................... 8-9

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Figure 8-5 CVWD encourages its wholesale customers to promote the notification of reuse water benefits ...................................................................... 8-12 Figure 8-6 A luncheon was held in King County, Wash. to present data on reclaimed water used for irrigation, along with lunch featuring crops and flowers from the reuse irrigation study ................................................................. 8-17

Chapter 9 Figure 9-1 Geographic display of international water reuse case studies categorized by application ..................................................................................... 9-3 Figure 9-2 Global water reuse after advanced (tertiary) treatment: market share by application ............................................................................................... 9-6 Figure 9-3 Countries with greatest irrigated areas using treated and untreated wastewater ............................................................................................................. 9-9 Figure 9-4Reducing the pathogenic health risks from unsafe use of diluted wastewater.... 9-16 Figure 9-5 Multi-barrier approach to safeguard public health where wastewater treatment is limited ........................................................................... 9-17

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Dedication Daniel James Deely (1944-2012) This document is dedicated to Daniel James Deely, for his tireless dedication to a decades-long collaboration between EPA and USAID and to the Guidelines for Water Reuse. It is because of Dan’s vision that this collaboration came about and was sustained. Dan served more than 40 years with USAID working on environmental and development projects worldwide. Dan was a walking reference for the history of the agency’s water programming. His wisdom, patience, strong dedication to the human development mission of USAID, and expertise are dearly missed by his colleagues and his extended network of professional contacts.

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Acknowledgements The Guidelines for Water Reuse was first published in 1980 and was updated in 1992 and 2004. Since then, water reuse practices have continued to develop and evolve. This edition of the Guidelines offers new information and greater detail about a wide range of reuse applications and introduces new concepts and treatment technologies supporting water reuse operations. It includes an updated inventory of state reuse regulations and expanded coverage of water reuse practices in countries outside of the United States. More than 300 reuse experts contributed text and case studies to highlight how reuse applications can and do work in the real world. The 2012 Guidelines for Water Reuse stands on the foundation of information generated by the substantial research and development efforts and extensive demonstration projects on water reuse practices throughout the world. Some of the most useful sources consulted in developing this update include conference proceedings, reports, and journal articles published by a range of organizations, including: the WateReuse Association (WRA), WateReuse Research Foundation (WRRF), Water Environment Federation (WEF), Water Environment Research Foundation (WERF), and AWWA. The National Research Council’s Water Reuse: Potential for Expanding the Nation's Water Supply Through Reuse of Municipal Wastewater 2012 report was a timely and key contribution to the information contained in this document. This study takes a comprehensive look at the potential for reclamation and reuse of municipal wastewater to expand and enhance water supply alternatives. The 2012 Guidelines for Water Reuse was developed by CDM Smith Inc. through a CRADA with EPA and USAID. Partial funding to support preparation of the updated document was provided by EPA and USAID. IWMI also provided technical, financial, and in-kind support for the development of Chapter 9 and the international case studies. We wish to acknowledge the direction, advice, and suggestions of the EPA Project Manager for this document, Robert K. Bastian of the Office of Wastewater Management; Dan Deely and Emilie Stander, PhD of USAID; and Jonathan Lautze, PhD and Pay Drechsel, PhD of IWMI. The CDM Smith project management team also reached out to the U.S. Department of Agriculture for input through James Dobrowolski and the U.S. Centers for Disease Control through Maxwell Zarate-Bermudez. The CDM Smith project management team was led by Project Director Robert L. Matthews, P.E., DEE and included Project Manager Katherine Y. Bell, PhD, P.E., BCEE; Technical Director Don Vandertulip, P.E., BCEE; and Technical Editors Allegra da Silva, PhD and Jillian Jack, P.E. Additional support was provided by Stacie Cohen, Alex Lumb, and Marcia Rinker of CDM Smith.

The process to create this document is outlined in Updating the Guidelines. We would like to express gratitude to the technical review committee who so painstakingly reviewed this document. The technical review committee included: 

Marc Andreini, PhD, P.E., University of Nebraska Robert B. Daugherty Water for Food Institute



Robert B. Brobst, P.E., EPA, Region 8



James Crook, PhD, P.E., BCEE, Environmental Engineering Consultant



Shivaji Deshmukh, P.E., West Basin Municipal Water District



Julie Minton, WRRF



James Dobrowolski, USDA/NIFA



Mark E. Elsner, P.E., South Florida Water Management District



Wm. Bart Hines, P.E., Trinity River Authority of Texas

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Carrie Miller, EPA, Office of Ground Water and Drinking Water



Craig Riley, Washington State Department of Health



Joan B. Rose, PhD, Michigan State University



Valerie Rourke, CPSS, CNMP, Virginia Department of Environmental Quality

Special thanks go to our colleagues who took their time to share professional experiences and technical knowledge in reuse to make these guidelines relevant and interesting. These contributors provided text or case studies; contributors who compiled and/or edited major sections of text are indicated with an asterisk (*). In addition, some members of the technical review committee contributed significant contributions of text. Please note that the listing of these contributors does not necessarily identify them as supporters of this document or represent their ideas or opinions on the subject. These persons are leaders in the field of water reuse, and their expertise has added to the depth and breadth of the document. Solomon Abel, P.E. CDM Smith San Juan, Puerto Rico

Robert Angelotti Upper Occoquan Sewage Authority (UOSA) Centreville, VA

Constantia Achileos, MSc Sewerage Board of Limassol Amathus Limassol, Cyprus

David Arseneau, P.Eng, MEPP AECOM Kitchener, Ontario, Canada

Robert Adamski, P.E., BCEE Gannett Fleming Woodbury, NY

Shelly Badger City of Yelm Yelm, WA

Pruk Aggarangsi, PhD Energy Research and Development Nakornping, Chiang Mai University Chaing Mai, Thailand Sohahn Akhtar CDM Smith Atlanta, GA Priyanie Amerasinghe, PhD International Water Management Institute Andhra Pradesh, India David Ammerman, P.E. AECOM Orlando, FL Bobby Anastasov, MBA City of Aurora Aurora, CO Daniel T. Anderson, P.E., BCEE CDM Smith West Palm Beach, FL Rolf Anderson USAID

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Institute-

Kathy Bahadoorsingh, PhD, R.Eng AECOM Trinidad K. Balakrishnan United Tech Corporation Delhi, India Jeff Bandy, PhD Carollo Engineers Boise, ID Randy Barnard, P.E. California Department of Public Health San Diego, CA Carl Bartone Environmental Engineering Consultant Bonita Springs, FL Somnath Basu, PhD, P.E., BCEE Shell Oil Co. Houston, TX Jim Bays, P.W.S. CH2M Hill

2012 Guidelines for Water Reuse

*Katherine Bell, PhD, P.E., BCEE CDM Smith Nashville, TN

Sally Brown, PhD University of Washington Seattle, WA

Ignacio Benavente, Eng, PhD University of Piura Piura, Peru

Tom Bruursema NSF International Ann Arbor, MI

Alon Ben-Gal, PhD Agricultural Research Organization, Gilat Research Center Negev, Israel

Laura Burton CDM Smith Cambridge, MA

Nan Bennett, P.E. City of Clearwater Clearwater, FL Jay Bhagwan Water Research Commission Johannesburg, South Africa Rajendra Bhardwaj Central Pollution Control Board Delhi, India Heather N. Bischel, PhD Engineering Research Center (ERC) for Reinventing the Nation's Urban Water Infrastructure (ReNUWIT), Stanford University Stanford, CA Jacob Boomhouwer, P.E. CDM Smith Portland, OR Lucas Botero, P.E., BCEE CDM Smith West Palm Beach, FL Keith Bourgeous, PhD Carollo Engineers Sacramento, CA Paul Bowen, PhD The Coca-Cola Company Atlanta, GA Andrew Brown, P.E. City of Phoenix Phoenix, AZ Randolph Brown City of Pompano Beach Pompano Beach, FL

2012 Guidelines for Water Reuse

Laura Cameron, BSBM City of Clearwater Clearwater, FL Celeste Cantú Santa Ana Watershed Project Authority Riverside, CA *Guy Carpenter, P.E. Carollo Engineers Phoenix, AZ Edward Carr ICF International San Rafael, CA *Bruce Chalmers, P.E. CDM Smith Irvine, CA Peter Chapman Sydney Water Corporation Penrith, New South Wales, Australia Cody Charnas CDM Smith Denver, CO Ana Maria Chavez, Eng, MSc University of Piura Piura, Peru Rocky Chen, P.E. Oklahoma Department of Environmental Quality Oklahoma City, OK Henry Chin, PhD The Coca-Cola Company Atlanta, GA, US Richard Cisterna Natural Systems Utilities, Inc. Hillsborough, NJ

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Joseph Cleary, P.E., BCEE HDR/HydroQual Mahwah, NJ

Dnyanesh V Darshane, PhD, MBA The Coca-Cola Company Atlanta, GA

Tracy Clinton, P.E. Carollo Engineers Walnut Creek, CA

William Davis CDM Smith Denver, CO

Stacie Cohen CDM Smith Cambridge, MA

Gary Dechant Laboratory Quality Systems Grand Junction, CO

Octavia Conerly EPA Office of Science and Technology Washington, D.C.

Gina DePinto Orange County Water District Fountain Valley, CA

Teren Correnti CDM Smith Carlsbad, CA

Clint Dolsby City of Meridian Meridian, ID

*Joseph Cotruvo, PhD Joseph Cotruvo and Associates Washington, D.C.

Amy Dorman, P.E. City of San Diego San Diego, CA

Jim Coughenour City of Phoenix Phoenix, AZ

Karen Dotson, Retired Tucson Water Tucson, AZ

*Patti Craddock, P.E. Short Elliott Hendrickson Inc. St. Paul, MN

*Pay Drechsel, PhD International Water Management Institute (IWMI) Colombo, Sri Lanka

Donald Cutler, P.E. CDM Smith Carlsbad, CA

Jörg Drewes, PhD Colorado School of Mines Golden, CO

*Allegra K. da Silva, PhD CDM Smith Wethersfield, CT

William Dunivin Orange County Water District Fountain Valley, CA

Walter Daesslé-Heuser, PhD Autonomous University of Baja California (UABC) Ensenada, Baja California, Mexico

Yamaji Eiji University of Tokyo Tokyo, Japan

Arnon Dag, PhD Agricultural Research Organization, Gilat Research Center Gilat, Israel

Mark Elbag Town of Holden Holden, MA

Liese Dallbauman, PhD PepsiCo Chicago, IL Marla Dalton City of Raleigh, NC Raleigh, NC xxii

Jeroen H. J. Ensink, PhD London School of Hygiene and Tropical Medicine London, England Lucina Equihua Degremont, S.A. de C.V. Mexico City, Mexico

2012 Guidelines for Water Reuse

Kraig Erickson, P.E. RMC Water and Environment Los Angeles, CA

Naoyuki Funamizu , Dr. Eng. Hokkaido University Sapporo, Japan

Ramiro Etchepare, MSc Universidade Federal do Rio Grande do Sul Port Alegre, Brazil

Jocelyn L. Cheeks Gadson, PMP The Coca-Cola Company Atlanta, GA

Patrick J. Evans, PhD CDM Smith Bellevue, WA

Elliott Gall University of Texas Austin, TX

Rob Fahey, P.E. City of Clearwater Clearwater, FL

Patrick Gallagher, JD CDM Smith Cambridge, MA

Johnathan Farmer Jones Hawkins & Farmer, PLC Nashville, TN

*Monica Gasca, P.E. Los Angeles County Sanitation Districts Whittier, CA

MerriBeth Farnham HD PR Group Fort Myers, FL

Daniel Gerrity, PhD UNLV Las Vegas, NV

James Ferguson, P.E. Miami Dade Water and Sewer Department Miami, FL

Patrick Girvin GE Boston, MA

Diana Lila Ferrando, Eng, MSc University of Piura Piura, Peru

Victor Godlewski City of Orlando Orlando, FL

Colin Fischer Aquacell Leura, New South Wales, Australia

Scott Goldman, P.E., BCEE RMC Water and Environment Irvine, CA

*Peter Fox, PhD Arizona State University Tempe, AZ

Fernando Gonzalez Degremont, S.A. de C.V. Mexico City, Mexico

Mary Fralish City of Mankato Mankato, MN

Albert Goodman, P.E. CDM Smith Louisville, KY

Tim Francis, P.E., BCEE ARCADIS Phoenix, AZ

Leila Goodwin, P.E. Town of Cary Cary, NC

Steven A. Friedman, P.E., PMP HDR Engineering Riverside, CA

Charles G. Graf, R.G. Arizona Department of Environment Quality Phoenix, AZ

Paul Fu , PhD, P.E. Water Replenishment District Lakewood, CA

Thomas Grizzard, PhD, P.E. Virginia Tech Manassas, VA

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Amit Gross, PhD Ben Gurion University of the Negev Sede Boqer, Midreshet Ben Gurion, Israel

Robert Hultquist California Department of Public Health El Cerrito, CA

*Elson Gushiken ITC Water Management, Inc. Haleiwa, Hawaii

Christopher Impellitteri, PhD US Environmental Protection Agency Cincinnati, OH

Juan M. Gutierrez, MS Javeriana University Bogota, Colombia

Ioanna Ioannidou, MSc, MBA Larnaca Sewerage and Drainage Board Larnaca, Cyprus

Brent Haddad, MBA, PhD UC Santa Cruz Santa Cruz, CA

Kevin Irby, P.E. CDM Smith Raleigh, NC

Josef Hagin, PhD Grand Water Research Institute Technion – Israel Institute of Technology Haifa, Israel

*Jillian Jack, P.E. CDM Smith Atlanta, GA

*Ken C. Hall, P.E. CH2M HILL Fort Worth, TX Laura Hansplant, RLA, ASLA, LEED AP Andropogon Associates (formerly) and Roofmeadow Philadelphia, PA Earle Hartling Los Angeles County Sanitation Districts Whittier, CA Damian Higham Denver Water Denver, CO

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Veronica Jarrin, P.E. CH2M HILL Atlanta, GA Raymond Jay Metropolitan Water District Los Angeles, CA

Mohammad Jitan, PhD National Center for Agricultural Research and Extension Baq'a, Jordan

Grant Hoag, P.E. Black and Veatch Irvine, CA

Abigail Holmquist, P.E. Honeywell Des Plaines, IL

Afsaneh Janbakhsh, MSc, Cchem, MRSC, Csci Northumbrian Water Ltd Chelmsford, Essex, United Kingdom

Blanca Jiménez-Cisneros, PhD Universidad Nacional Autónoma de México Mexico City, Mexico

Mark Hilty, P.E. City of Franklin TN Franklin, TN

Rita Hochstrat, MTechn. University of Applied Switzerland Muttenz, Switzerland

JoAnn Jackson, P.E. Brown and Caldwell Orlando, FL

Sciences

Northwestern

Patrick Jjemba, PhD American Water Mary Joy Jochico USAID Manilla, Philippines Rony Joel, P.E., DEE AEC Water Marco Island, FL

2012 Guidelines for Water Reuse

Grace Johns, PhD Hazen and Sawyer Hollywood, FL

Stuart Khan, PhD University of South Wales Sydney, New South Wales, Australia

Daniel Johnson, P.E. CDM Smith Atlanta, GA

Robert Kimball, P.E., BCEE CDM Smith Helena, MT

Jason Johnson, P.E. CDM Smith Miami, FL

Katsuki Kimura, Dr.Eng. Hokkaido University Sapporo, Japan

Geoff Jones Barwon Water Geelong, Victoria, Australia

Kenneth Klinko, P.E. CDM Smith Carlsbad, CA

Jayne Joy, P.E. Eastern Municipal Water District Perris, CA

*Nicole Kolankowsky, P.E. Black and Veatch Orlando, FL

Graham Juby, PhD, P.E. Carollo Engineers Riverside, CA

Ariel Lapus USAID-PWRF Project Manilla, Philippines

Bader Kassab, MSc USAID Baq'a, Jordan

Cory Larsen, P.E. North Carolina Department of Environment and Natural Resources Raleigh, NC

Sara Katz Katz & Associates, Inc. San Diego, CA Andrew Kaye, P.E. CDM Smith Orlando, FL Christian Kazner, Dr.-Ing. University of Technology Sydney Sydney, Australia Uday Kelkar, PhD, P.E., BCEE NJS Consultants Co. Ltd Pune, India Diane Kemp CDM Smith Tampa, FL Bernard Keraita, PhD International Water Management Institute (IWMI) and Copenhagen School of Global Health Kumasi, Ghana Zohar Kerem, PhD The Hebrew University of Jerusalem Rehovot, Israel 2012 Guidelines for Water Reuse

Roberta Larson, JD California Association of Sanitation Agencies Sacramento, CA James Laurenson Health & Environmental Assessment Consulting Bethesda, MD *Jonathan Lautze, PhD International Water Management Institute (IWMI) Pretoria, South Africa Jamie Lefkowitz, P.E. CDM Smith Cambridge, MA Richard Leger, CWP City of Aurora Aurora, CO Elizabeth Lemonds Colorado Department Environment Denver, CO

of

Public

Health

and

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Liping Lin GE Water and Power Beijing, China Enrique López Calva CDM Smith San Diego, CA Maria Loucraft City of Pompano Beach Pompano Beach, FL Karen Lowe, P.E. CDM Smith Tampa, FL Alex Lumb CDM Smith Cambridge, MA Linda Macpherson CH2M HILL Portland, OR Peter Macy, P.E. CDM Smith Pretoria, South Africa Ben Manhas New Jersey Department of Environmental Protection Trenton, NJ Mike Markus, P.E., D.WRE Orange County Water District Fountain Valley, CA

Naeem Mazahreh, PhD National Center for Agricultural Research and Extension Baq'a, Jordan Peter McCornick International Water Management Institute (IWMI) Colombo, Sri Lanka J. Torin McCoy NASA Houston, TX Karen McCullen, P.E., BCEE CDM Smith Orlando, FL Ellen T. McDonald, PhD, P.E. Alan Plummer Associates, Inc. Fort Worth, TX Rachael McDonnell, PhD International Center for Biosaline Agriculture Dubai, United Arab Emirates Ted McKim, P.E., BCEE Reedy Creek Energy Services Lake Buena Vista, FL Jean E.T. McLain, PhD University of Arizona Tucson, AZ Kevin S. McLeary, P.E. Pennsylvania Department of Environmental Protection

W. Kirk Martin, P.G. CDM Smith Ft. Myers, FL

Matt McTaggart, P.Eng, R.Eng AECOM

Pablo Martinez SAWS San Antonio, TX

Sharon Megdal, PhD University of Arizona Tucson, AZ

Ignacio Martinez Texas A&M AgriLife Research Center at El Paso El Paso, TX

Leopoldo Mendoza-Espinosa, PhD Autonomous University of Baja California (UABC) Ensenada, Baja California, Mexico

Jim Marx, MSc, P.E. AECOM Washington, D.C.

Tracy Mercer, MBA City of Clearwater Clearwater, FL

*Robert Matthews, P.E., DEE CDM Smith Rancho Cucamungo, CA

Mark Millan Data Instincts Windsor, CA

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Wade Miller WateReuse Association Alexandria, VA

Tressa Nicholas Idaho Department of Environmental Quality Boise, ID

*Dianne Mills CDM Smith Charlotte, NC

Joan Oppenheimer, BCES MWH Arcadia, CA

Seiichi Miyamoto, PhD Texas A&M AgriLife Research Center at El Paso El Paso, TX

Kerri Jean Ormerod University of Arizona Tucson, AZ

Jeff Moyer Rodale Institute Kutztown, PA

David Ornelas El Paso Water Utilities El Paso, TX

Rafael Mujeriego, PhD Universidad Politécnica de Cataluña Barcelona, Spain

Alysia Orrel CDM Smith Newport News, VA

Richard Nagel, P.E. West Basin Municipal Water Districts Carson, CA

John Emmanuel T. Pabilonia USAID

Sirenn Naoum, PhD National Center for Agricultural Research and Extension Amman, Jordan Eileen Navarrete, P.E. City of Raleigh Public Utilities Department Raleigh, NC Margaret Nellor Nellor Environmental Associates Austin, TX Chad Newton, P.E. Gray & Osborne, Inc. Seattle, WA My-Linh Nguyen, PhD, P.E. Nevada Division of Environmental Protection Carson City, NV Viet-Anh Nguyen, PhD National University of Civil Engineering Hanoi, Vietnam Lan Huong Nguyen, MSc National University of Civil Engineering Hanoi, Vietnam Seydou Niang, PhD Cheikh Anta Diop University of Dakar Dakar, Senegal 2012 Guidelines for Water Reuse

Alexia Panayi, MBA Water Development Department Nicosia, Cyrpus Lynne Pantano Consultant Orange County, CA Iacovos Papaiacovou Sewerage Board of Limassol Amathus Limassol, Cyprus James M. Parks, P.E. North Texas Municipal Water District Wylie, TX Carl Parrott Oklahoma Department of Environmental Quality Oklahoma City, OK Meha Patel, P.E. CDM Smith Los Angeles, CA Mehul Patel, P.E. Orange County Water District Fountain Valley, CA Thomas Pedersen CDM Smith Cambridge, MA

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Harold Perry King County, WA Seattle, WA Danielle Pieranunzi, LEED AP BD+C Sustainable Sites Initiative Austin, TX Belinda Platts, MSc Monterey Regional Water Pollution Control Agency Monterey, CA Megan H. Plumlee, PhD, P.E. Kennedy/Jenks Consultants San Francisco, CA H. Plummer, Jr., P.E., BCEE Alan Plummer Associates, Inc. Fort Worth, TX Jim Poff Clayton County Water Authority Morrow, GA Arlene Post CDM Smith Los Angeles, CA Steve Price, P.E. Denver Water Denver, CO Lisa Prieto, P.E, BCEE Cater Verplanck Orlando, FL Muien Qaryouti, PhD National Center for Agricultural Research and Extension Baq'a, Jordan

Eugene Reahl GE David Requa, P.E. Dublin San Ramon Services District Dublin, CA *Alan Rimer, PhD, P.E., DEE Black and Veatch Cary, NC Marcia Rinker CDM Smith Denver, CO Jon Risgaard North Carolina Department of Environment and Natural Resources Raleigh, NC Channah Rock, PhD Soil Water and Environmental Science, University of Arizona Tuscon, AZ Steve Rohrer, P.E. ARCADIS Phoenix, AZ Alberto Rojas Comisíon Estatal del Agua San Luis Potosí, Mexico Irazema Rojas, P.E. El Paso Water Utilities El Paso, TX C. Donald Rome, Retired Southwest Florida Water Management District Brooksville, FL

Joseph Quicho City of San Diego San Diego, CA

Joel A. Rosenfield The Coca-Cola Company Atlanta, GA

Daphne Rajenthiram CDM Smith Austin, TX

Debra Ross King County Wastewater Treatment Division Seattle, WA

Alison Ramoy SWFWMD Brooksville, FL

Jonathan Rossi Western Municipal Water District Riverside, CA

Laura Read Tufts University Medford, MA

Suzanne Rowe, P.G., C.HG. CDM Smith Irvine, CA

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2012 Guidelines for Water Reuse

A. Robert Rubin, PhD Professor Emeritus, NC State University Raleigh, NC Jorge Rubio, PhD, DIC Universidade Federal do Rio Grande do Sul Porto Alegre, Brazil Lluís Sala Consorci Costa Brava Girona, Spain Fernando Salas Tufts University Medford, MA Steve Salg Denver Zoo Denver, CO *Andrew Salveson, P.E. Carollo Engineers Walnut Creek, CA Mike Savage, P.E. Brown and Caldwell Irvine, CA Roger Schenk CDM Smith Austin, TX Michael Schmidt, P.E., BCEE CDM Smith Jacksonville, FL Larry Schwartz, PhD, P.W.S. South Florida Water Management District West Palm Beach, FL Christopher Scott, PhD University of Arizona Tucson, AZ Harry Seah, MSc Singapore Public Utilities Board Singapore Mark Sees City of Orlando Orlando, FL Eran Segal, PhD Agricultural Research Organization, Gilat Research Center Gilat, Israel 2012 Guidelines for Water Reuse

Raphael Semiat, PhD Grand Water Research Institute Technion – Israel Institute of Technology Haifa, Israel *Bahman Sheikh, PhD, P.E. Water Reuse Consultant San Francisco, CA *Eliot Sherman EPA Washington, D.C. Arun Shukla NJS Engineers India Pvt. Ltd. Bangalore, India Menachem Yair Sklarz, PhD Ben Gurion University of the Negev Sede Boqer, Midreshet Ben Gurion, Israel Theresa R. Slifko, PhD Sanitation Districts of Los Angeles County Whittier, CA David Sloan, P.E., BCEE Freese and Nichols Fort Worth, TX David Smith, PhD WateReuse California Sacramento, CA Erin Snyder, PhD University of Arizona Tucson, AZ Shane Snyder, PhD University of Arizona Tucson, AZ Maria Ines Mancebo Soares, PhD Ben Gurion University of the Negev Sede Boqer, Midreshet Ben Gurion, Israel *Shanin Speas-Frost, P.E. Florida Department of Environmental Protection Tallahassee, FL Rebecca Stack District Department of the Environment Washington, D.C. Christopher Stacklin, P.E. Orange County Sanitation District Fountain Valley, CA xxix

Mary Stahl, P.E. Olsson Associates Golden, CO *Emilie Stander, PhD USAID Washington, D.C. Benjamin Stanford, PhD Hazen and Sawyer Raleigh, NC Bill Steele USBR Temecula, CA Marsi Steirer City of San Diego San Diego, CA Jo Sullivan King County, WA Seattle, WA Greg Taylor, P.E. CDM Smith Maitland, FL *Patricia Tennyson Katz and Associates San Diego, CA Michael Thomas CCWA Morrow, GA Donald Thompson, PhD, P.E. CDM Smith Jacksonville, FL Ching-Tzone Tien, PhD, P.E. Maryland Department of the Environment Baltimore, MD Jennifer Troy CDM Smith Cambridge, MA Ryujiro Tsuchihashi, PhD AECOM Burnaby, BC, Canada Anthony Van City of San Diego San Diego, CA

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Emmanuel Van Houtte IWVA, 'Intercommunale Waterleidingsmaatschapij van Veurne-Ambacht' translated 'Intermunicipal Water Company of the Veurne Region' Doornpannestraat, Koksijde, Belgium *Don Vandertulip, P.E., BCEE CDM Smith San Antonio, TX Milind Wable, PhD, P.E., BCEE NJS Consultants Co. Ltd San Diego, CA Kenny Waldrup, P.E. City of Raleigh, NC Raleigh, NC Michael Walters Lake Simcoe Region Conservation Authority Newmarket, Ontario, Canada Elizabeth Watson, P.E., LEED AP CDM Smith Cambridge, MA Jennifer Watt, P.E. GE Oakville, Ontario, Canada Michael P. Wehner Orange County Water District Fountain Valley, CA Kirk Westphal, P.E. CDM Smith Cambridge, MA Gregory D Wetterau, P.E., BCEE CDM Smith Raleigh, NC Carolyn Ahrens Wieland Booth, Ahrens & Werkenthin, PC Austin, TX Michael Wilson, P.E. CH2M HILL Boston, MA Anna Wingard CDM Smith New York, NY

2012 Guidelines for Water Reuse

*Lee Wiseman, P.E., BCEE CDM Smith Orlando, FL Chester J. Wojna The Coca-Cola Company Atlanta, GA Steven Wolosoff CDM Smith Rancho Cucamonga, CA Chee Hoe Woo, MSc Singapore Public Utilities Board Singapore Mauri L. Wood CDM Smith Franklin, TN Tim Woody City of Raleigh Raleigh, NC Elizabeth Ya'ari Friends of the Earth Middle East Bethlehem, Palestinian Territories Alexander Yakirevich, PhD Ben Gurion University of the Negev Sede Boqer, Midreshet Ben Gurion, Israel Eiji Yamaji, PhD University of Tokyo Chiba Prefecture, Japan

2012 Guidelines for Water Reuse

Uri Yermiyahu, PhD Agricultural Research Organization, Gilat Research Center Gilat, Israel David Young, P.E., BCEE, FACEC CDM Smith Cambridge, MA Ronald Young, P.E., DEE Elsinore Valley Municipal Water District Lake Elsinore, CA Rafael Zaneti, MSc Universidade Federal do Rio Grande do Sul Porto Alegre, Brazil Maribel Zapater, MSc University of Piura Piura, Peru Max Zarate-Bermudez,MSc, MPH, PhD CDC/NCEH Atlanta, GA Meiyang Zhou, MSc Ben Gurion University of the Negev Sede Boqer, Midreshet Ben Gurion, Israel Christine Ziegler Rodale Institute Kutztown, PA

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The following individuals also provided special assistance or review comments on behalf of EPA: Robert K. Bastian EPA Office of Wastewater Management Washington, D.C.

Cheryl McGovern EPA Region 9 San Francisco, CA

Phil Berger, PhD EPA Office of Ground Water and Drinking Water Washington, D.C.

George Moore EPA Office of Research and Development Cincinnati, OH

Veronica Blette EPA Office of Wastewater Management Washington, D.C.

Dan Murray, P.E., BCEE EPA Office of Research and Development Cincinnati, OH

Octavia Conerly EPA Office of Science and Technology Washington, D.C.

Joseph Morris Tinker AFB Midwest City, OK

Michael J. Finn EPA Office of Ground Water and Drinking Water Washington, D.C.

Tressa Nicholas, MSCE Idaho Department of Environmental Quality Water Quality Division Boise, ID

Ellen Gilinsky, PhD EPA Office of Water Washington, D.C. Bonnie Gitlin EPA Office of Wastewater Management Washington, D.C. Robert Goo EPA Office of Wetlands Oceans and Watersheds Washington, D.C. James Goodrich, PhD EPA Office of Research and Development Cincinnati, OH Roger Gorke EPA Office of Water Washington, D.C. Audrey Levine, PhD Battelle Memorial Institute Washington, D.C.

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Charles Noss, PhD EPA Office of Research and Development Research Triangle Park, NC George O'Connor, PhD University of Florida Gainesville, FL Phil Oshida EPA Office of Ground Water and Drinking Water Washington, D.C. Nancy Yoshikawa EPA Office of Wetlands Oceans and Watersheds Washington, D.C. Carrie Wehling EPA Office of General Council Washington, D.C. J. E. Smith, Jr, D.Sc, MASCE, BCEEM (Retired) EPA Office of Research and Development Cincinnati, OH

2012 Guidelines for Water Reuse

Frequently Used Abbreviations and Acronyms ANSI

American National Standards Institute

AOP

advanced oxidation processes

ASR

aquifer storage and recovery

BOD

biochemical oxygen demand

CBOD

carbonaceous biochemical oxygen demand

COD

chemical oxygen demand

CWA

Clean Water Act

DBP

disinfection by-product

DO

dissolved oxygen

DOC

dissolved organic carbon

DPR

direct potable reuse

EDC

endocrine disrupting compounds

EPA

U.S. Environmental Protection Agency

FDEP

Florida Department of Environmental Protection

GAC

granular activated carbon

HACCP

Hazard Analysis and Critical Control Points

IPR

indirect potable reuse

IRP

integrated resources plan

LEED

Leadership in Energy and Environmental Design

MBR

membrane bioreactor

MCL

maximum contaminant level

MF

microfiltration

NDMA

N-nitrosodimethylamine

NPDES

National Pollutant Discharge Elimination System

PPCP

pharmaceuticals and personal care product

PCR

polymerase chain reaction

POC

particulate organic carbon

RO

reverse osmosis

SAT

soil-aquifer treatment

SDWA

Safe Drinking Water Act

SRT

solids retention time

TDS

total dissolved solids

TMDL

total maximum daily load

TOC

total organic carbon

TrO

trace organic compounds

TSS

total suspended solids

TWM

total water management

UF

ultrafiltration

USACE

U.S. Army Corps of Engineers

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USAID

U.S. Agency for International Development

USDA

U.S. Department of Agriculture

WHO

World Health Organization

WPCF

water pollution control facility

WRF

water reclamation facility

WRA

WateReuse Association

WRRF

WateReuse Research Foundation

WWTF

wastewater treatment facility

WWTP

wastewater treatment plant

2012 Guidelines for Water Reuse

CHAPTER 1 Introduction Recognizing the need to provide national guidance on water reuse regulations and program planning, the U.S. Environmental Protection Agency (EPA) has developed comprehensive, up-to-date water reuse guidelines in support of regulations and guidelines developed by states, tribes, and other authorities. Water reclamation and reuse standards in the United States are the responsibility of state and local agencies—there are no federal regulations for reuse. The first EPA Guidelines for Water Reuse was developed in 1980 as a technical research report for the EPA Office of Research and Development (EPA, 1980). It was updated in 1992 to support both project planners and state regulatory officials seeking EPA guidance on appropriate water quality, uses, and regulatory requirements for development of reclaimed water systems in the various states (EPA, 1992). The primary purpose of the update issued in 2004 was to summarize water reuse guidelines, with supporting research and information, for the benefit of utilities and regulatory agencies, particularly in the United States (EPA, 2004). As of the publication of the 2012 updated document, 30 states and one U.S. territory have adopted regulations and 15 states have guidelines or design standards that govern water reuse. The updated guidelines serve as a Figure 1-1 national overview of The 2004 EPA Guidelines for the status of reuse Water Reuse has had global regulations and clarify influence. some of the variations in the regulatory frameworks that support reuse in different states and regions of the United States. Globally, the EPA Guidelines for Water Reuse has also had far-reaching influence. In fact, some countries either reference the document or adopt the guiding principles outlined in the 2004 guidelines. Many countries of the world also reference the World Health

2012 Guidelines for Water Reuse

Organization (WHO) Guidelines for the Safe Use of Wastewater, Excreta and Greywater. Over the last decade there has been significant growth in the application of reuse, important advances in reuse technologies, and an increase in the number of states that have implemented either rules or guidelines for reuse. In addition, growing worldwide water supply demands have forced planners to consider nontraditional water sources while maintaining environmental stewardship. In response to these changes and advances in reuse, EPA has developed the 2012 Guidelines for Water Reuse to incorporate this information through a Cooperative Research and Development Agreement (CRADA) with CDM Smith and an Interagency Agreement with U.S. Agency for International Development (USAID).

1.1 Objectives of the Guidelines

There were several key reasons to update the guidelines in 2012. As the field of reuse has expanded greatly over the past decade, there is a need to address new applications and advances in technologies, as well as update state regulatory information. As technologies are now advanced enough to treat wastewater to the water quality required for the intended use, the concept of “fit for purpose” is highlighted to emphasize the efficiencies realized by designing reuse for specific end applications. Second, EPA has committed to work with communities to incorporate the approach of integrated water management, where nonconventional water sources are incorporated as part of holistic water management planning, a theme that is emphasized in this update (Rodrigo et al., 2012). Third, there was interest in incorporating findings and recommendations from the National Research Council’s (NRC) Water Science & Technology Board report, Water Reuse: Potential for Expanding the Nation's Water Supply Through Reuse of Municipal Wastewater (NRC, 2012). Globally, the WHO has also updated its guidelines, which were under revision at the time of publication of the 2004 EPA guidelines document. In response to these changes and other advances in reuse technologies, EPA deemed it appropriate and

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Chapter 1 | Introduction

necessary to revise its guidelines document to include updated information. As a result, facilitated workshops and informational sessions were initiated in 2009 at water events around the world to generate feedback about concepts that should be repeated, updated, added, or removed from the document; the current version of the Guidelines for Water Reuse incorporates this information. In states and nations where standards do not exist or are being revised or expanded, the EPA guidelines can assist in developing reuse programs and appropriate regulations. The guidelines also will be useful to engineers and others involved in the evaluation, planning, design, operation, or management of water reclamation and reuse facilities. Because the number of reuse applications has expanded so significantly since publication of the 2004 document, this revision has modified the format and scope of case studies to provide readers with examples of best practices and lessons learned. Additionally, the chapter on international reuse has been expanded to include a discussion of principles for mitigating risks associated with wastewater use where treatment does not exist and enabling factors for expanding wastewater treatment to promote the increase of water reuse. The chapter also provides case studies of global experiences that can inform approaches to reuse in the United States.

1.2 Overview of the Guidelines

Stakeholder input was gathered from a wide range of contributors in order to identify key themes to emphasize in this update. The stakeholder involvement process is described in further detail in Updating the Guidelines. This input has been integrated throughout the document, which has been arranged by topic and devotes separate chapters to each of the key technical, financial, legal and institutional, and public involvement issues. While the document generally follows the outline of the 2004 guidelines, integration of some of the new materials resulted in expanded chapters that required minor reorganization. The document is organized into nine chapters and six appendices, as outlined in Table 1-1.

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Throughout the text, case studies are introduced and referenced by a [code name] in brackets. In the compiled pdf version of this document, hyperlinks will direct the reader to the case studies in the appendices. The U.S. case studies are listed and contained in Appendix D. International case studies are listed and contained in Appendix E.

1.3 Guidelines Terminology

The terminology associated with treating municipal wastewater and reusing it varies both within the United States and globally. For instance, although the terms are synonymous, some states and countries use the term reclaimed water while others use the term recycled water. Similarly, the terms water recycling and water reuse have the same meaning. In this document, the terms reclaimed water and water reuse are used. Definitions of terms used in this document, with the exception of their use in case studies, which may contain site-specific terminology, are provided below. De facto reuse: A situation where reuse of treated wastewater is, in fact, practiced but is not officially recognized (e.g., a drinking water supply intake located downstream from a wastewater treatment plant [WWTP] discharge point). Direct potable reuse (DPR): The introduction of reclaimed water (with or without retention in an engineered storage buffer) directly into a drinking water treatment plant, either collocated or remote from the advanced wastewater treatment system. Indirect potable reuse (IPR): Augmentation of a drinking water source (surface or groundwater) with reclaimed water followed by an environmental buffer that precedes drinking water treatment. Nonpotable reuse: All water reuse applications that do not involve potable reuse. Potable reuse: Planned augmentation of a drinking water supply with reclaimed water.

2012 Guidelines for Water Reuse

Chapter 1 | Introduction

Table 1-1 Organization of 2012 Guidelines for Water Reuse Chapter Overview of Contents EPA’s Total Water Management (TWM) approach to water resources planning is described as a framework within which water reuse is integrated into a holistic water management approach. Chapter 2–Planning and The steps that should be considered in the planning stage as part of an integrated water Management resources plan are then presented, followed by an overview of key considerations for managing Considerations reclaimed water supplies. These discussions cover management of supplies as well as managed aquifer recharge, which has progressed substantially since publication of the previous guidelines.

Chapter 3–Types of Reuse Applications

A discussion of reuse for agricultural, industrial, environmental, recreational, and potable supplies is presented. An expanded discussion of indirect potable reuse (IPR) and direct potable reuse (DPR) is also provided with references to new research and literature. Urban reuse practices such as fire protection, landscape irrigation, and toilet flushing were described in great detail in the 2004 guidelines and are not repeated here; however, general information regarding planning and management of reclaimed water supplies and systems that include urban reuse is provided in Chapter 2.

Chapter 4–State Regulatory Programs for Water Reuse

An overview of legal and institutional considerations for reuse is provided in this chapter. The chapter also gives an updated summary of existing state standards and regulations. At the end of this chapter are suggested minimum guidelines for water reuse in areas where such guidance or rules have not yet been established.

Chapter 5–Regional Variations in Water Reuse

This new chapter summarizes current water use in the United States and discusses expansion of water reuse nationally to meet water needs. The chapter discusses variations in regional drivers for water reuse, including population and land use, water usage by sector, water rates, and the states’ regulatory contexts. Representative water reuse practices are described for each region, and U.S. water reuse case studies are introduced.

Chapter 6–Treatment Technologies for Protecting Public and Environmental Health

This chapter provides an overview of the treatment objectives for reclaimed water and discusses the major treatment processes that are fundamental to production of reclaimed water. And, while this chapter is not intended to be a design manual or provide comprehensive information about wastewater treatment, which can be found in other industry references, an overview of these processes and citations for updated industry standards is provided.

Chapter 7–Funding Water Reuse Systems

Assuring adequate funding for water reuse systems is similar to funding other water services. Because of increased interest in using reclaimed water as an alternate water source, this chapter provides a discussion of how to develop and operate a sustainable water system using sound financial decision-making processes that are tied to the system’s strategic planning process.

Chapter 8–Public Outreach, Participation, and Consultation

This chapter presents an outline of strategies for informing and involving the public in water reuse system planning and reclaimed water use and reflects a significant shift in thinking toward a higher level of public engagement since publication of the last guidelines. This chapter also describes some of the new social networking tools that can be tapped to aid with this process.

Chapter 9–Global Experiences in Water Reuse

With significant input from USAID and the International Water Management Institute (IWMI), the chapter on international reuse has been expanded to include a description of the growth of advanced reuse globally. In addition, this chapter provides information on principles for mitigating risks associated with the use of untreated or partially treated wastewater, enabling factors for expanding water reuse, and new case studies that can provide informed approaches to reuse in the United States.

APPENDIX A

Federal and nonfederal agencies that fund research in water reuse

APPENDIX B

Inventory of water reuse research projects

APPENDIX C

State regulatory websites

APPENDIX D

Case studies on water reuse in the United States

APPENDIX E

Case studies on water reuse outside the United States

APPENDIX F

List of case studies that were included in the 2004 EPA guidelines

APPENDIX G

Abbreviations for names of states and units of measure

2012 Guidelines for Water Reuse

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Chapter 1 | Introduction

Reclaimed water: Municipal wastewater that has been treated to meet specific water quality criteria with the intent of being used for a range of purposes. The term recycled water is synonymous with reclaimed water.

including graywater and stormwater, are discussed in Chapter 2.

Water reclamation: The act of treating municipal wastewater to make it acceptable for reuse.

In addition to the general terms defined above, the following terminology is used in this document to delineate between categories of water reuse applications (Table 1-2).

Water reuse: The use of treated municipal wastewater (reclaimed water). Other alternate sources of water,

Wastewater: Used water discharged from homes, business, industry, and agricultural facilities.

Table 1-2 Categories of water reuse applications Category of reuse Description Unrestricted

The use of reclaimed water for nonpotable applications in municipal settings where public access is not restricted

Restricted

The use of reclaimed water for nonpotable applications in municipal settings where public access is controlled or restricted by physical or institutional barriers, such as fencing, advisory signage, or temporal access restriction

Food Crops

The use of reclaimed water to irrigate food crops that are intended for human consumption

Processed Food Crops and Nonfood Crops

The use of reclaimed water to irrigate crops that are either processed before human consumption or not consumed by humans

Unrestricted

The use of reclaimed water in an impoundment in which no limitations are imposed on body-contact water recreation activities

Restricted

The use of reclaimed water in an impoundment where body contact is restricted

Urban Reuse

Agricultural Reuse

Impoundments

Environmental Reuse

The use of reclaimed water to create, enhance, sustain, or augment water bodies including wetlands, aquatic habitats, or stream flow

Industrial Reuse

The use of reclaimed water in industrial applications and facilities, power production, and extraction of fossil fuels

Groundwater Recharge – Nonpotable Reuse

The use of reclaimed water to recharge aquifers that are not used as a potable water source

IPR Potable Reuse DPR

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Augmentation of a drinking water source (surface or groundwater) with reclaimed water followed by an environmental buffer that precedes normal drinking water treatment The introduction of reclaimed water (with or without retention in an engineered storage buffer) directly into a water treatment plant, either collocated or remote from the advanced wastewater treatment system

2012 Guidelines for Water Reuse

Chapter 1 | Introduction

1.4 Motivation for Reuse

The ability to reuse water, regardless of whether the intent is to augment water supplies or manage nutrients in treated effluent, has positive benefits that are also the key motivators for implementing reuse programs. These benefits include improved agricultural production; reduced energy consumption associated with production, treatment, and distribution of water; and significant environmental benefits, such as reduced nutrient loads to receiving waters due to reuse of the treated wastewater. As such, in 2012, the drivers for reuse are similar to those presented in the 2004 guidelines and center around three categories: 1) addressing urbanization and water supply scarcity, 2) achieving efficient resource use, and 3) environmental and public health protection.

1.4.1 Urbanization and Water Scarcity The present world population of 7 billion is expected to reach 9.5 billion by 2050 (USCB, n.d.).

(2012), the potential municipal water supply offset by reuse for a community of 1 million people will be approximately 75 mgd (3,950 L/s) or 27,400 million gallons (125 MCM) per year. Given losses at various points in the overall system and potential downstream water rights, the actual available water would most likely be about 50 percent of the potential value, but the resulting impact on the available water supply would still be impressive. As urban areas continue to grow, pressure on local water supplies will continue to increase. Already, groundwater aquifers used by over half of the world population are being overdrafted (Brown, 2011). As a result, it is no longer advisable to use water once and dispose of it; it is important to identify ways to reuse water. Reuse will continue to increase as the world’s population becomes increasingly urbanized and concentrated near coastlines, where local freshwater supplies are limited or are available only with large capital expenditure (Creel, 2003).

In addition to the increasing need to meet potable water supply demands and other urban demands (e.g., landscape irrigation, commercial, and industrial needs), increased agricultural demands due to greater incorporation of animal and dairy products into the diet also increase demands on water for food production (Pimentel and Pimentel, 2003). These increases in population and a dependency on high-water-demand agriculture are coupled with increasing urbanization; all of these factors and others are effecting land use changes that exacerbate water supply challenges. Likewise, sea level rise and increasing intensity and variability of local climate patterns are predicted to alter hydrologic and ecosystem dynamics and composition (Bates et al., 2008). For example, the western United States, including the Colorado River Basin, which provides water to 35 million people, is projected to experience seasonal and annual temperature increases, resulting in increased evaporation (Garfin et al., 2007; Cohen, 2011).

Energy efficiency and sustainability are key drivers of water reuse, which is why water reuse is so integral to sustainable water management. The water-energy nexus recognizes that water and energy are mutually dependent—energy production requires large volumes of water, and water infrastructure requires large amounts of energy (NCSL, 2009). Water reuse is a critical factor in slowing the compound loop of increased water and energy use witnessed in the water-energy nexus. A frequently-cited definition of sustainability comes from a 1987 report by the Bruntland Commission: “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (WCED, 1987). Therefore, sustainable water management can be defined as water resource management that meets the needs of present and future generations.

Reuse projects must factor in climate predictions, both for demand projections and for ecological impacts. Municipal wastewater generation in the United States averages approximately 75 gpcd (284 Lpcd) and is relatively constant throughout the year. Where collection systems are in poor condition, the wastewater generation rate may be considerably higher or lower due to infiltration/inflow or exfiltration, respectively. Thus, according to Schroeder et al.

Water reuse is integral to sustainable water management because it allows water to remain in the environment and be preserved for future uses while meeting the water requirements of the present. Water and energy are interconnected, and sustainable management of either resource requires consideration of the other. Water reuse reduces energy use by eliminating additional potable water treatment and associated water conveyance because reclaimed

2012 Guidelines for Water Reuse

1.4.2 Water-Energy Nexus

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Chapter 1 | Introduction

water typically offsets potable water use and is used locally. For example, about 20 percent of California’s electricity is consumed by water-related energy use, including potable water conveyance, storage, treatment, and distribution and wastewater collection, treatment, and discharge (California Energy Commission, 2005). Although additional energy is required to treat wastewater for reclamation, the amount of energy required for treatment and transport of potable water is generally much greater in southern California. And the estimated net energy savings could range from 0.7 to 1 TWh/yr, or 3,000 to 5,000 kWh/Mgal. At a power cost of $0.075/kWh, the savings would be on the order of $50 to $87 million per year (Schroeder et al., 2012).

Understanding that reuse is one of the tools that urban water/wastewater/stormwater managers have at their disposal to improve their existing systems’ energy efficiency, EPA is currently developing a handbook titled Leveraging the Water-Energy Connection—An Integrated Resource Management Handbook for Community Planners and Decision-Makers, envisioned to be an integrated water management-planning support document. The manual will address water conservation and efficiency (which is discussed in these guidelines with respect to its role in TWM), as well as alternative water sources (reclaimed water, graywater, harvested stormwater, etc.) as part of capacity development, building codes for improved water and energy-use efficiency, and renewable energy sources from/for both water and wastewater systems.

1.4.3 Environmental Protection

Figure 1-2 Purple pipe is widely used for reclaimed water distribution systems (Photo credit: CDM Smith)

The energy required for capturing, treating, and distributing water and the water required to produce energy are inextricably linked. Water reuse can achieve two benefits: offsetting water demands and providing water for energy production. As described in Chapters 3 and 5, thermoelectric energy generation currently uses about half of the water resources consumed in the United States and is a major potential user of reclaimed water (Kenny et al., 2005). On-site energy and resource efficiency is also driving the installation of decentralized reuse applications in industrial applications and establishments seeking Leadership in Energy and Environmental Design (LEED) certification. EPA has developed principles for an Energy-Water Future that incorporate familiar concepts of: efficiency, a water-wise energy sector as well as an energy-wise water sector, consideration of wastewater as a resource, and integrated resource planning and recognition of the societal benefits (EPA, 2012).

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Water scarcity and water supply demands in arid and semi-arid regions drive reuse as an alternate water supply; however, there are still many water reuse programs in the United States that have been initiated in response to rigorous and costly requirements to remove nutrients (mainly nitrogen and phosphorus) from effluent discharge to surface waters. Environmental concerns over negative impacts from increasing nutrient discharges to coastal waters are resulting in mandatory reductions in the number of ocean discharges in Florida and California. By eliminating effluent discharges for all or even a portion of the year through water reuse, a municipality may be able to avoid or reduce the need for costly nutrient removal treatment processes or maintain wasteload allocations while expanding capacity. Avoiding costly advanced wastewater treatment facilities was the key driver for St. Petersburg, Fla., to initiate reclaimed water distribution to residential, municipal, commercial, and industrial demands when the state legislature enacted the Wilson-Grizzle Act in 1972, significantly restricting nutrient discharge into Tampa Bay. Today, St. Petersburg serves more than 10,250 residential connections in addition to parks, schools, golf courses, and commercial/industrial applications, including 13 cooling towers. Another current example is King County, Wash., which is implementing reuse to reduce the discharge of nutrients into Puget Sound to address the health of this marine water [US-WA-King County].

2012 Guidelines for Water Reuse

Chapter 1 | Introduction

Under some National Pollutant Discharge Elimination System (NPDES) programs, water reuse may have evolved from initial land treatment system or zero discharge system concepts. The reuse program in this circumstance may serve dual objectives. First, the system could treat as much effluent on as little land as possible (thus, application rates are often greater than irrigation demands), with subsequent “disposal” of the remaining fraction. And second, the evolution of this treatment process could provide an alternate water supply when water reuse practices are implemented. Many communities are also turning to water reuse to achieve environmental goals of maintaining flows to sensitive ecosystems, such as in Sierra Vista, Ariz.; San Antonio, Texas; and Sydney, Australia [US-AZ-Sierra Vista, US-TX-San Antonio, and Australia-Replacement Flows].

1.5 "Fit for Purpose"

While the increased use of reclaimed water typically poses greater financial, technical, and institutional challenges than traditional sources, a range of treatment options are available such that any level of water quality can be achieved depending upon the use of the reclaimed water. This is also reflective of the evolution of reclaimed water from its origins as land application and treatment for disposal of treated wastewater effluent for groundwater recharge and crop production to the advanced treatment processes that are applied today to meet potable water quality for indirect potable reuse. Indeed, the NRC’s Water Science & Technology Board recently acknowledged this continuum of reuse practices in its 2012 report, Water Reuse: Potential for Expanding the Nation's Water Supply Through Reuse of Municipal Wastewater (NRC, 2012), with the following statement:

“A portfolio of treatment options, including engineered and managed natural treatment processes, exists to mitigate microbial and chemical contaminants in reclaimed water, facilitating a multitude of process combinations that can be tailored to meet specific water quality objectives. Advanced treatment processes are also capable of addressing contemporary water quality issues related to potable reuse involving emerging pathogens or trace organic chemicals. Advances in membrane filtration have made membrane-based processes particularly attractive for water reuse applications. However, limited cost-effective concentrate disposal alternatives hinder the application of membrane technologies for water reuse in inland communities” (NRC, 2012). This concept is represented graphically in Figure 1-3, which illustrates that water treatment technologies (combined with disinfection) offer a ladder of increasing water quality, and choosing the right level of treatment should be dictated by the end application of the reclaimed water for achieving economic efficiency and environmental sustainability. There are numerous case studies that demonstrate the balance of treatment costs along with the intended use of the reclaimed water. Many of these develop reuse in the interest of replacing the use of drinking water for nonpotable applications and meeting the future water demands. As such, the treatment level required for reclaimed water production depends on the end use. A number of states, such as Washington, California, Florida, Arizona, and others, prescribe the level of treatment depending on the end use. This recognition of “Fit for Purpose” provides a framework for cost-effective treatment to be applied to a water

Figure 1-3 Treatment technologies are available to achieve any desired level of water quality

2012 Guidelines for Water Reuse

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Chapter 1 | Introduction

source sufficient to meet the quality appropriate for the intended use. By selecting appropriate treatment for specific applications, water supply costs can be controlled and the costs for improved wastewater treatment technologies delayed until they are balanced by the benefits. Consideration must also be balanced with the potential for future reuse of higher reclaimed water quality such that these uses are not limited.

1.6 References Bates, B. C., Z. W. Kundzewicz, S. Wu, and J. P. Palutikof. 2008. Climate Change and Water. Technical paper. Intergovernmental Panel on Climate Change. Geneva. Brown, L. R. 2011. “The New Geopolitics of Food,” Foreign Policy, 4, 1 – 11. California Department of Water Resources (2011). Notice to State Water Project Contractors. State Water Project Analyst’s Office. Retrieved August 2012 from . California Energy Commission. 2005. Final Staff Report, California’s Water-Energy Relationship, CEC-700-2005-011SF. Retrieved August 2012 from . Cohen, M. 2011. Municipal Deliveries of Colorado River Basin Water. Pacific Institute. Oakland, CA. Creel, L. 2003. "Ripple Effects: Population and Coastal Regions,” Population Reference Bureau. Washington, D.C. Garfin, G., M. A. Crimmins, and K. L. Jacobs. 2007. “Drought, Climate Variability, and Implications for Water Supply.” In Colby, B.G. and K.L. Jacobs, (eds.) Arizona Water Policy: Management Innovations in an Urbanizing Arid Region. Resources for the Future. Washington, D.C. Kenny, J. F., N. L. Barber, S. S. Hutson, K. S. Linsey, J. K. Lovelace, and M. A. Maupin. 2005. Estimated Use of Water in the United States in 2005. United States Geological Survey (USGS). Retrieved April 5, 2012, from . National Conference of State Legislatures (NCSL). 2009. Overview of the Water-Energy Nexus in the U.S. Retrieved August 2012 from .

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National Research Council (NRC). 2012. Water Reuse: Potential for Expanding the Nation's Water Supply Through Reuse of Municipal Wastewater. The National Academies Press: Washington, D.C. Pimentel, D., and M. Pimentel. 2003. “Sustainability of Meatbased and Plant-based Diets and the Environment.” American Journal of Clinical Nutrition. 78(3):660S-663S. Rodrigo, D., E. J. López Calva, and A. Cannan. 2012. Total Water Management. EPA 600/R-12/551. U.S. Environmental Protection Agency. Washington, D.C. Schroeder, E., G. Tchobanoglous, H. L. Leverenz, and T. Asano. 2012. Direct Potable Reuse: Benefits for Public Water Supplies, Agriculture, the Environment, and Energy Conservation, National Water Research Institute (NWRI) White Paper, Publication Number NWRI-2012-01. Fountain Valley, CA. United States Census Bureau (USCB). n.d. World Population. Accessed on September 17, 2012 from . U.S. Environmental Protection Agency (EPA). 1980. Protocol Development: Criteria and Standards for Potable Reuse and Feasible Alternatives. 570/9-82-005. Environmental Protection Agency. Washington, D.C. U.S. Environmental Protection Agency (EPA). 1992. Guidelines for Water Reuse. 625/R92004. Environmental Protection Agency. Washington, D.C. U.S. Environmental Protection Agency (EPA). 2004. Guidelines for Water Reuse. 625/R-04/108. Environmental Protection Agency. Washington, D.C. U.S. Environmental Protection Agency (EPA). Energy/Water. Retrieved August 2012 .

2012. from

World Commission on Environment and Development (WCED). 1987. Our Common Future: The Bruntland Report. United Nations World Commission on Environment and Development. Oxford University Press. New York, NY.

2012 Guidelines for Water Reuse

CHAPTER 2 Planning and Management Considerations With increasing restrictions on conventional water resource development and wastewater discharges, reuse has become an essential tool in addressing both water supply and wastewater disposal needs in many areas. This growing dependence on reuse makes it critical to integrate reuse programs into broader planning initiatives. Since publication of the 2004 guidelines, some excellent materials on planning, developing, and managing reuse systems have been published and are referenced in this chapter. A summary of overarching management themes and discussion of some important management practices and tools are provided in this chapter.

heavily discharge wastewater and stormwater into receiving waters. Traditional Water Management (Non-integrated Water Resources)

Water Supply

As described in the document Total Water Management (Rodrigo et al., 2012), receiving waters (Figure 2-1) represent surface and groundwater resources that provide both water supply sources and points of wastewater discharge. Dry weather stormwater represents low flows that occur during nonpeak events that may end up in the wastewater collection system, and wet weather stormwater represents higher flow periods that generally end up as discharge to receiving waters (Rodrigo et al., 2012). In the non-integrated approach, urban watersheds use more receiving waters for their water supplies and

2012 Guidelines for Water Reuse

dry weather

Stormwater wet weather

Receiving Waters

Total Water Management (Integrated Water Resources) Beneficial reuse of stormwater (e.g., groundwater recharge)

2.1 Integrated Water Management Beyond the need to address water supply challenges, many utility systems are under increasing pressures to save costs and demonstrate environmental stewardship. Under this scenario, weaknesses in the traditional practices of water management, which typically focus on individual resources or utilities, have become apparent. Recognizing these challenges, application of adaptive management approaches, such as integrated water management, is a means of improving water resource management and reducing waste streams (Rodrigo et al., 2012). This approach is the result of a focus on broader water resources management options that encompass all of the water resource systems within a community, and reuse is a key factor in this more holistic planning method. Figure 2-1 illustrates the difference between integrated and nonintegrated water resources management approaches.

Wastewater

Water Supply

Wastewater

dry weather

Stormwater

Reduced flows from BMPs

Reclaimed water

wet weather

Receiving Waters

Figure 2-1 Traditional versus Integrated Water Management (adapted from O’Connor et al., 2010)

This approach can result in detrimental environmental impacts and lead to inefficiencies in the use of water. Integrated water management significantly improves the opportunities to obtain benefits from water, regardless of the stage in the water cycle. Concepts such as integrating water conservation practices to reduce the demand for freshwater are part of this comprehensive management approach. Also, rather than viewing stormwater as a nuisance, it should be considered an asset that is allowed to recharge groundwater through best management practices (BMPs), such as the use of swales, porous pavement, or cisterns. Additionally, wastewater can be reused, providing both environmental and water supply benefits. The end result of integrated water management is reduced discharges to receiving waters and reduced reliance on surface and groundwater supplies to meet water demands. The following set of management

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Chapter 2 | Planning and Management Considerations

strategies and alternative resources are typically considered in an integrated water management plan: 

Water conservation



Reuse of wastewater



Reuse of graywater



Stormwater BMPs



Rainwater harvesting



Enhanced groundwater recharge



Increased surface water detention



Dry weather urban runoff treatment



Dual plumbing for potable and nonpotable uses



Separate distribution systems for fire protection



Multi-purpose infrastructure



Use of the right water quality for intended use



Green roofs



Low impact development (LID)

An example of this new approach to water resources planning is the Integrated Resources Plan (IRP) of Los Angeles, Calif. In 1999, Los Angeles embarked on an entirely new approach for managing its water resources. The IRP took a holistic, watershed approach by developing a partnership among different city departments that managed water supply, wastewater, and stormwater (CDM, 2005; López Calva et al., 2001). The goal was to develop multi-purpose, multi-benefit strategies to address chronic droughts, achieve compliance with water quality laws (e.g., total maximum daily loads [TMDLs]), provide additional wastewater system capacity, increase open space, reduce energy consumption, manage costs, and improve quality of life for its citizens. Completed in 2006, the IRP won numerous awards and was wellsupported by the city’s diverse stakeholders (CH:CDM, 2006a, 2006b, and 2006c). Projects identified in the IRP will be implemented over the next 20 years. When the strategies that were evaluated as part of the IRP development were compared to traditional water management practices, integrated water management scenarios demonstrated greater benefits at lower total present value costs than the baseline traditional approach scenario. While the results in the city of Los Angeles IRP were largely driven by the higher cost for imported water,

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which is very susceptible to droughts, there are other motives for integrated planning. The city of San Diego [US-CA-San Diego] is conducting an 18-month demonstration project in 2012 to demonstrate the potential of IPR. Pending the results of the demonstration project, the city would mine treated wastewater effluent from the outfall serving the Point Loma Primary Treatment Plant to provide water higher in quality than drinking water standards and augment the supply of the San Vicente Reservoir. Drivers for this project include an expanded water supply, reduction of coastal discharges, and lower energy consumption compared to importation of new supplies or ocean desalination. In other areas of the country, this integrated management approach may also produce greater benefits for water management, and not necessarily for water supply alone. Even smaller communities can benefit from examining water resources in a more interconnected and integrated manner. Franklin, Tenn. [US-TN-Franklin] has proactively adopted this management approach through the integrated water resources planning process. The city has reached beyond the typical application of this management tool to improve the overall services of the drinking water, wastewater, stormwater, and reclaimed water systems. The end result is that the city of Franklin, through a stakeholder participation process, has developed a long-term plan that will ultimately protect the Harpeth River—a source of water supply, a receiving body for treated effluent, a recreational waterway, and one of the community’s most prized recreational resources. Under the umbrella of an integrated plan, the development and management of facilities and policies for water, wastewater, stormwater, reclaimed water, and energy can be evaluated concurrently. Not only does this process bring together resources that share a common environment, it brings together the people who manage or are affected by these resources and their infrastructure, which is one of the reasons the integrated planning process is gaining in appeal. In this process, elected officials rely on the consensus backing of stakeholders, and the IRP process inherently strives to achieve goals that are common to all participating stakeholders (discussed further in Chapter 8). Specific guidance and examples of how water planners and managers can use the IRP process as an objective and balanced means of exploring the relative merits of considering reuse options alongside traditional water supply and demand

2012 Guidelines for Water Reuse

Chapter 2 | Planning and Management Considerations

management alternatives is provided in the research report titled, Extending the Integrated Resource Planning Process to Include Water Reuse and Other Nontraditional Water Sources (WRRF, 2007a). The report provides an extensive description of each of the elements of the IRP process, the issues and opportunities related to incorporating reuse into integrated plans, and the tools and models that can be used for facilitating appropriate reuse applications into an integrated management plan. Additional information is also provided in the document, Total Water Management (Rodrigo et al., 2012). Integral to the successful implementation of integrated water management is a regulatory framework that facilitates rather than obstructs this approach. The various managed components of an integrated water resources plan, which may include water, wastewater, stormwater, reclaimed water, and energy, may be regulated by different state agencies and, in some cases, one component may be regulated by more than one state agency. Some state agencies, particularly those that have been delegated Clean Water Act (CWA), NPDES, and Safe Drinking Water Act (SDWA) federal programs, have deliberately elected to establish clear boundaries to avoid any potential for redundancy and confusion for the public. In the case of an IPR proposal, however, aspects of the project might require involvement and possibly permitting by multiple agencies. The degree of coordination and cooperation that can be achieved may vary from project to project and from state to state. Therefore, states committed to achieving integrated water resources planning goals may choose to adopt laws that consolidate regulatory programs to the extent possible or improve the coordination and cooperation among programs of different state agencies for the purpose of facilitating this planning framework. Subsequently, regulatory programs developed on the basis of these laws should provide greater focus and details on implementation of more integrated solutions.

2.2 Planning Municipal Reclaimed Water Systems

Regardless of the size and type of a reclaimed water system, there are planning steps that should be considered (although an industrial process recycle system may have different process control drivers). Planning should be consistent with the overall water resources management objectives, which should be defined through an integrated planning process

2012 Guidelines for Water Reuse

(Section 2.1). As part of an integrated water resources plan, a reclaimed water master plan can identify acceptable community uses for reclaimed water, potential customers and their demands, and the quality of water required. Planners must also determine the volume of reclaimed water available for distribution, paying attention to the diurnal discharge curve at the community WWTP. This is an important consideration that can drive many other planning decisions as water conservation practices often require evening or early morning irrigation when low flows to the WWTP occur. If irrigation will occur during low influent wastewater periods, the supply of reclaimed water may not be adequate to meet the instantaneous demands, unless the reclaimed water demand rate is low compared to current treatment plant capacity. Storage is one option to resolve this supply/demand imbalance. As part of the initial viability assessment, it is critical to examine federal and state laws, regulations, rules, and policies. Frameworks of state regulations are described in Chapter 4. In addition to the state regulatory context, certain overarching federal and state natural resource and environmental impact laws apply at the planning stage. The National Environmental Policy Act (NEPA) requires an assessment of environmental impacts for all projects receiving federal funds and subsequent mitigation of all significant impacts. Many states also have equivalent rules that mandate environmental impact assessment and mitigation planning for all projects prior to construction. These requirements often stipulate terms of public review. Even in cases where it is not legally required, stakeholder involvement in the planning of a water-reuse system is important and can help to achieve a successful outcome, as described in Chapter 8. Other laws protect biological, scenic, and cultural resources. These laws can result in a de facto moratorium on the construction of large-scale water diversions (by dams) that flood the habitat of protected species or inundate pristine canyons or areas of historical significance. These laws are of particular relevance where new water supply is under consideration. In some cases these laws make reuse more attractive than new source development, but they may impact seasonal storage options for reclaimed water.

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Chapter 2 | Planning and Management Considerations

To further examine project viability, the following project-planning steps taken from the WateReuse Association Manual of Practice serve as a guide (WRA, 2009): A. Identify quantity of reclaimed water available B. Screen all existing and potential future uses and users C. Identify potential users D. Determine if users will accept reclaimed water E. Compare supply to potential demand F. Prepare distribution system layout G. Finalize customer list H. Determine economic feasibility I.

Compile final user list and distribution

J.

Prepare point-of-sale facilities

K. Obtain regulatory approval L. Perform on-site retrofits M. Perform cross-connection test N. Begin delivering water While the WateReuse Association Manual of Practice provides details on each of these steps, a number of considerations are worth further exploration.

2.2.1 Identifying Users and Types of Reuse Demands Because permitted uses vary greatly between states, a review of individual state regulations is important so the utility has a thorough understanding of how reclaimed water is regulated and what uses are allowed. Once regulations and allowed uses are fully understood, a utility may review water usage records to identify and locate some of its largest users. Focusing first on the largest water users helps the utility get the best possible return on investment, as well as maximize its benefits to the potable water system. In addition to water records, aerial photographs can be useful in identifying users who could utilize reclaimed water for irrigation purposes (such as golf courses and other recreational facilities). Variables such as an area’s climate, state regulations, and common industries will determine the best potential reclaimed water customers. Irrigation of golf courses and recreational facilities may be the most

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well-known application of reclaimed water, but there are a number of less-traditional applications that can provide a utility with significant potable water savings: 

Irrigation and toilet flushing in large government facilities, such as capital complexes, schools, hospitals, colleges, and prisons



Irrigation and toilet flushing in sports franchises, large arenas, and planned community centers



Brownfield redevelopment



Various uses in commercial and manufacturing processes



Industrial fire protection



Stream restoration/augmentation (where regulations allow)

The most reliable customers will be those who can utilize nonpotable water daily and throughout the year, such as in boilers and chillers or in a manufacturing process. These potential customers with a consistent usage rate will provide the utility with a baseline usage and will not be affected by wet or dry weather. A utility can count on these customers to provide turnover in pipelines during cool and/or wet periods and to provide a certain amount of consistent revenue. Additionally, within an integrated management approach, a utility may want to consider where the application of reuse provides the most value to the overall water supply system. Providing reclaimed water to commercial or industrial customers using a potable system nearing its capacity or to any users competing for the same limited resources as the utility may be more advantageous than supplying irrigation water to the local golf course, even if the latter is provided at a higher cost. Similarly, supplying reclaimed water to hydrate an impacted wetland or to control saline water movement within a critical aquifer system may allow continued or expanded use of a limited conventional water resource. Once initial potential users are identified, information should be gathered about the best way to get reclaimed water to them.

2.2.2 Land Use and Local Reuse Policy Most communities in the United States engage in some type of structured planning process whereby the local jurisdiction regulates land use development according to a general plan, sometimes reinforced with

2012 Guidelines for Water Reuse

Chapter 2 | Planning and Management Considerations

zoning regulations and similar restrictions. Developers of approved areas for new development may be required to prepare specific plans that demonstrate sufficient water supply or wastewater treatment capacity. In these contexts, dual-piped systems may be developed at the outset of development. It is important that any reuse project conforms to requirements under the general plan to ensure the project does not face legal challenges on a land use basis. Local planning processes often include public notice and hearings. As the public may have many misconceptions about reclaimed water, it is important for planners to address public concerns or opposition, as described in depth in Chapter 8. Chapter 5 of the 2004 guidelines identified land use and environmental regulation controls used by local government entities to implement and manage reclaimed water systems; this chapter also identified mandatory use requirements in California. Since publication of the 2004 guidelines, many communities and states have implemented more formal water planning processes to meet public health needs for adequate water, wastewater, and reclaimed water services. There are several reasons a utility might create a local policy to require connection to a reclaimed water system, with parallel logic used in many communities to require connection to municipal utilities when reasonably available. The most common reason to require connection is to assure use of the new system, adequate to shift some of the water demand and to pay for the new system or defer new potable main construction. In an integrated water management program, potable water supplies may be limited and require construction of a reclaimed water/dual water system to meet the total demand. Even if reclaimed water is priced lower than the potable supply, the public may not have been adequately informed to understand the benefits of a diversified water system and may resist conversion to reclaimed water. Mandatory connection to reclaimed water systems is becoming more common. Planning for future use of reclaimed water allows communities to require certain uses to utilize reclaimed water if reasonably available. Because construction cost for retrofit with a dual water system is higher and disruption of other infrastructure is unavoidable, dual water piping can be installed initially with the nonpotable distribution system dedicated to irrigation, cooling towers, or industrial

2012 Guidelines for Water Reuse

processes. When reclaimed water is available to the development area, a connection to the supply is the only local construction required. Utilities may also need to secure bonds used for construction with an ordinance requiring connection to a reclaimed water system, thus providing a guarantee of future cash flow to meet bond payments. In addition to state legislative action in California (identified in Chapter 5 of the previous guidelines), many utilities have included mandatory connection language. Water Recycling Funding Program Guidelines initially issued in 2004 and amended in July 2008 require loan/grant applicants to include a draft mandatory use ordinance in their application packet (SWRCB, 2009). Text in the Marina Coast Water District Ordinance, Title 4, 4.28.030 Recycled water service availability, includes: A. When recycled water is available to a particular property, as described in Section 1.04.010, the owner must connect to the recycled water system. The owner must bear the cost of completing this connection to the recycled water system. B. New water users who are not required to connect to recycled water because the distance to the nearest recycled water line is greater than the distance provided in Section 1.04.010, shall be required to construct isolated plumbing infrastructure for landscape irrigation or other anticipated nonpotable uses, with a temporary connection to the potable water supply. C. All new private or public irrigation water systems, whether currently anticipating connection to the recycled system or that shall be connected to the potable water system temporarily while awaiting availability of recycled water, shall be constructed of purple polyvinyl chloride (PVC) pipe to the existing district standard specification” (Marina Coast Water District, 2002). Examples of other California utilities with mandatory connection requirements include Dublin San Ramon Services District (DSRSD); Inland Empire Utility Agency; San Luis Obispo Rowland Heights; Cucamonga Valley Water District; and Elsinore Valley Municipal Water District. Florida is another state with mandatory connection requirements; 78 counties, cities, and private utilities responded on their 2011

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Chapter 2 | Planning and Management Considerations

annual reuse reports that they either require construction of reclaimed water piping in new residential or other developments or require connection to reuse systems when they become available. The Florida communities of Altamonte Springs; Boca Raton; Brevard, Charlotte, Polk, Colombia, Palm Beach, and Seminole Counties; Marco Island; and Tampa are examples. There are no communities in Texas with mandatory connections, but requirements were also found in Yelm, Wash.; Cary, N.C.; and Westminster, Md. Along with the mandatory connection requirement, there are also ordinances that promote use of reclaimed water through incentives. The St. Johns River Water Management District, Fla., provides a model water conservation ordinance to cities within the district to promote more water efficient landscape irrigation. The model ordinance includes time-of-day/ day-of-week restrictions based on odd-even street address as well as daily irrigation limits of 0.75 in/day (1.9 cm/d). Exemptions may be granted to these limitations. Possible exemptions include using a microspray, micro-jet, drip, or bubbler irrigation system; establishing new landscape; or watering in lawn treatment chemicals. The use of water from a reclaimed water system is allowed anytime. The capacity of a reclaimed water system can be strained if customers continue to use reclaimed water beyond the utility capacity to supply it. In Cape Coral, Fla., the city council is considering an ordinance to reestablish an emergency water conservation plan due to a persistent drought since 2007 (Ballaro, 2012). The dry-season water demand—and the abuse of reclaimed water—has increased. As much as 42 3 million gallons (160,000 m ) of reclaimed water are being used each scheduled watering day, and 19 3 million gallons (72,000 m ) were being used on a day when no watering is allowed. The council is taking a proactive approach to protect the city’s water resources, including reclaimed water.

2.2.3 Distribution System Considerations It is important to keep in mind that reclaimed water distribution systems require many of the same planning and design considerations as potable water systems. And, because public water utilities are ultimately responsible for protecting the integrity of their water systems, safety programs addressing the potential for cross-connections must involve the public

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water authorities from inception. If a dual water system is being considered, planning for a new potable water system may be concurrent. Retrofits into existing developed areas, however, may require more effort as designers must identify all existing utilities to meet separation distances and avoid impacts to other utilities during construction. In any case, design of a reclaimed water distribution system should follow design standards required in the state where the project is implemented. Where reclaimed water criteria are not available, designers should apply the general engineering design standards applicable to potable water or irrigation systems, as appropriate. General guidelines will be provided in this section, and users of these guidelines are referred to other current design documents that can provide guidance for reclaimed water systems. The WateReuse Association Manual of Practice identifies the basic steps in developing a water reuse program, including system engineering criteria (WRA, 2009). American Water Works Association (AWWA) published the third edition of its Manual of Water Supply Practices M-24, which discusses planning, design, construction, operation, regulatory framework, and management of community dual water systems (AWWA, 2009). AWWA also is preparing a new Reclaimed Water Management Standard that will be the first in a planned series of management standards. Additional information on cross-connection control is also provided in the Cross-Connection Control Manual. EPA 816-R-03-002 (EPA, 2003). To develop a robust reclaimed water distribution system, it is important to provide an initial “backbone,” or primary transmission main, of sufficient size to allow the system to carry reclaimed water away from the source. The primary transmission main should be constructed in a location that will allow for connections to future lines as well as easy connection to previously identified large potable water users. Several items should be considered when evaluating potential routes for the primary transmission main of a reclaimed water distribution system, including: 

The location of previously identified potential users



The total amount of potable water to be saved by connecting these potential users to the reclaimed water distribution system

2012 Guidelines for Water Reuse

Chapter 2 | Planning and Management Considerations



The amount of potable water to be saved that is not dependent on weather or climate conditions



Other potential alternate route



Other utility or roadway projects that may be taking place around the same time as construction of the primary transmission main, which may help reduce initial capital costs

future

users

along

each

Coordination with other potential projects can help save a large amount of money in capital investment, and acquiring additional users (or positioning the utility to acquire additional users in the future) will help offset the capital investment and provide future revenue. With a new reclaimed water distribution system, especially in a state or region where reclaimed water is not yet common, customer and public education are critical components for making the project successful. Potential customers must be informed of the benefits of using reclaimed water instead of potable water for their nonpotable water needs. There may be a financial incentive for the first customers in a new system. In addition, any myths or misconceptions about reclaimed water need to be dispelled immediately and replaced with accurate information about the safety and quality of reclaimed water. Providing water quality data on reclaimed water may help ease customer concerns. As the distribution system grows, new users will be identified more easily. During periods of dry weather or drought, potential users will often identify themselves and help expand the system. Reuse systems often have different peak hours than potable water systems. Peak usage of a reclaimed water distribution system often occurs at night when large users are irrigating. To help shave the peaks from the system, a utility can set an irrigation schedule for large irrigation users. This will prevent too many large irrigation users from irrigating simultaneously and taxing the system. Requiring large users to maintain their own on-site storage can also control peak delivery rates and equalize flow within the system.

2.2.3.1 Distribution System Pumping and Piping To meet initial and projected demands, a hydraulic model using real data from potable water records can provide a realistic view of how much reclaimed water

2012 Guidelines for Water Reuse

could be used at both average and peak times. This will help determine the size of the primary transmission main, as well as initial or future storage. Hydraulic modeling can also identify optimum pipe diameters and routing for initial and expanded distribution systems. Integral to the choice of pipe diameters based on anticipated flow rates are decisions on utility and customer storage, time-of-day watering restrictions, and rate of delivery to the customer. Large irrigation customers, especially golf courses, may already have water features that are filled daily from existing water sources and that serve as storage for on-site irrigation systems. Automated irrigation systems are quite common at golf courses and are typically programmed to apply controlled amounts of water to meet course demands based on weather conditions and evapotranspiration data. A component of the user agreement may include limits on rate of delivery to fill an existing storage feature at a flat rate during a 24-hour period to maximize delivery capacity for the utility. The blend of large customers that have available storage and small customers that simply are willing to replace potable water at line pressure with reclaimed water at line pressure will influence system storage, pumping, and delivery main sizing. Most states require reclaimed water distribution piping to be purple, with the color integral to the pipe; Pantone 512 or 522 is often specified for this purpose (Figure 2-2). Reclaimed water piping should be identified in a manner consistent with state design criteria, which may include labeling or tags as well as signage along the piping alignment. Pipe material is often PVC, as color is readily incorporated into the pipe during manufacturing. For larger systems that use concrete steel cylinder pipe for transmission mains, purple dye can be added to the mortar during manufacture of the pipe, as is the practice for most of the large diameter pipes in the transmission lines in the San Figure 2-2 Antonio Water 36-inch CSC 301 purple mortar System (SAWS). pipe, San Antonio Water System (Photo credit: Don Vandertulip)

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Chapter 2 | Planning and Management Considerations

Where utility preference or construction conditions dictate the use of other pipe material, such as ductile iron pipe, purple plastic sleeves can be used to provide corrosion control and identify the water main as a reclaimed water main. Likewise, steel pipe can be painted and high density polyethylene (HDPE) pipe can be ordered with purple stripes integral to the pipe. Separation distances are required between reclaimed water pipes and water and sewer pipes, typically identified as 9 or 10 ft (3 m) pipe-to-pipe horizontal separation between reclaimed water and potable water piping. The same provision typically applies to separation distance between a reclaimed water pipe and a sanitary sewer main. Where a crossing occurs, the pipe with the highest quality product should be located above the other two, with 1 ft (0.3 m) vertical separation between any two pipes. Specifically, potable pipe should be above reclaimed water pipe, and reclaimed water pipe should be above the sanitary sewer main, as shown in Figure 2-3.

2.2.3.2 Reclaimed Water Appurtenances Reclaimed water distribution systems will have all of the appurtenances typical of a potable water system. Most of the typical system components are now available in purple to support increased installation of purple color-coded reclaimed water systems. Valve riser covers are often triangular or square to distinguish them from potable water covers; reclaimed water system valves can be ordered as plant valves with opposite open and close positions from potable valves. Backflow prevention devices, air relief valves, meter boxes, and sprinkler heads are all available in purple. All components and appurtenances of a nonpotable system should be clearly and consistently identified throughout the system. Identification should be through color coding and marking so that the nonpotable system (i.e., pipes, pumps, outlets, and valve boxes) is distinctly set apart from the potable system. The methods most commonly used are unique colorings, labeling, and markings.

Location of Public Water System Mains in Accordance with F.A.C. Rule 62-555.314

Figure 2-3 Appropriate separation of potable, reclaimed water, and sanitary sewer pipes (FDEP, n.d.) 2-8

2012 Guidelines for Water Reuse

Chapter 2 | Planning and Management Considerations

A reclaimed water distribution system typically requires signage at facilities (e.g., pump stations, storage, etc.), and some states require marking of utility pipelines along the alignment. For irrigation components that incorporate hose bibs, most state regulations require a locking hose vault or quick connection assembly to preclude unauthorized connection and use of the reclaimed water. Purple asset identification tags can be attached to valve box lids, valve handles, backflow preventers, and other appurtenances to readily identify these system components. All major irrigation system suppliers have snap-on components (rings) in purple that can be added to existing sprinkler heads, as shown in Figure 2-4. Purple Mylar pre-printed stickers are also popular and can be wrapped around pop-up sprinkler heads to identify the system as providing reclaimed water.

all pipe conveying alternate waters to be purple; alternate waters includes reclaimed water provided by the off-site municipal utility provider but also would include any other nonpotable water generated on the private property. The issue for many utilities is the significant water quality difference between municipally produced, tested, and distributed reclaimed water and other on-site water, including graywater, which is by definition “wastewater.” The second issue that surfaced was the plumbing code’s use of green pipe to designate potable water. In the municipal utility business, blue is the color used to designate potable water piping while green is used to designate wastewater. This identified a potential crossconnection problem that, to date, is unresolved.

2.2.3.3 On-site Construction Considerations Many reclaimed water providers provide guidance and instructions to property owners connecting to the reclaimed water system. This can include user manuals and training classes for on-site supervisors of commercial properties. These manuals and instructions typically cover state and local regulations related to reclaimed water, proper use, crossconnection control, and on-site construction standards and materials. Good examples of user manuals are those provided by SAWS and DSRSD (SAWS, 2006 and DSRSD, 2005). Tucson has developed an extensive cross-connection control program and a manual for its cross-connection control specialist; more information on the Tucson Site Inspection Program is available in a case study [US-AZ-Tucson]. Typically, utility design criteria apply within the public right-of-way, and locally-adopted plumbing code controls, construction practices, permits, and construction inspections apply for work on private property. There are two plumbing codes in general use within the United States: the Uniform Plumbing Code produced by the International Association of Plumbing and Mechanical Officials (IAPMO) and the International Plumbing Code produced by the International Code Council (ICC). Beginning in 2008, several professional organizations (WateReuse Association [WRA], Water Environment Federation [WEF], AWWA) serving reclaimed water utilities began a dialogue with IAPMO, and eventually also with ICC, attempting to change plumbing code pipe color requirements adopted in 2009. The proposal requires

2012 Guidelines for Water Reuse

Figure 2-4 Purple snap-on reclaimed water identification cap (Photo credit: Rain Bird)

Color coding of utility piping systems has been practiced for decades, and the roots of the current American National Standard Institute (ANSI) Standard Z-535 color standard in the United States can be traced back to the July 16, 1945 American Standard Association (ASA) approval of safety color standards at the request of the War Department (ANSI, 2007). The American Public Works Association (APWA) Uniform Color Standard was initially adopted in 1980 (Precaution Blue for water systems and Safety Green for sewer systems), and an updated policy that added purple for reclaimed water pipes was adopted in 2003. The use of purple pipe to designate reclaimed or recycled water was first adopted by the AWWA California-Nevada Section in 1997. The California Department of Health Services and Nevada Division of

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Environmental Protection reviewed and accepted the guidelines (AWWA, 1997). More recently, the Common Ground Alliance (CGA) was formed by the Department of Transportation in 1998, and in 2009 the CGA adopted the APWA Uniform Color Standard. The CGA Uniform Color Code and Marking Guideline, Appendix B (CGA, 2011) is the basis of color-code marking for the national One-Call System used to locate and mark underground utilities prior to construction (Vandertulip, 2011a). Three states have addressed the issue of on-site purple pipe application for conveyance of alternative waters. California adopted final rules for graywater systems that became effective January 27, 2010, as Title 5, Part 24, Chapter 16A Nonpotable Water Reuse Systems. Purple pipe requirements in California’s state code for recycled water (Title 22) were maintained for reclaimed water piping in a building, and Universal Product Code (UPC) 1610.2 state adoption of the plumbing code excludes reference to pipe color for alternate waters. In similar fashion, Florida adopted the International Plumbing Code (IPC) without adopting the pipe color code sections, while maintaining Section 602 requirements that reclaimed water be distributed in purple pipe. Washington state modified the base UPC in WAC 51-56-1600 Chapter 16—Gray water systems 1617.2.2 Other Nonpotable Reused Water to maintain yellow pipe with black text designating the type of nonpotable water while 1617.2.1 maintained purple pipe for reclaimed water (Vandertulip, 2011b).

2.2.4 Institutional Considerations The rules and regulations governing design, construction, and implementation of reuse systems are described in Section 2.2.3, and the practical implications of these rules can be found in Chapter 4. In addition to rules specifically aimed at water reuse projects, regulations governing utility construction in

general also apply. The details of such rules are beyond the scope of this document but can be promulgated by state agencies (including health departments) and local jurisdictions or can be established by federal grant or loan programs. Once facilities have been constructed, state and local regulations often require monitoring and reporting of performance, as described in Chapter 4. To provide production, distribution, and delivery of reclaimed water, as well as payment for it, a range of institutional arrangements can be utilized, as listed in Table 2-1. It is necessary to conduct an institutional inventory to develop a thorough understanding of the institutions with jurisdiction over various aspects of a proposed reuse system. On occasion there is an overlap of agency jurisdiction, which may cause conflict unless steps are taken early in the planning stages to obtain support and delineate roles. The following institutions should be involved or, at a minimum, contacted: federal and state regulatory agencies, administrative and operating organizations, and general units of local (city, town, and county) government. In developing a viable arrangement, it is critical that both public and private organizations be considered. As access to public funds decrease, the potential for private capital investment increases. It is vital that the agency or entity responsible for financing the project be able to assume bonded or collateralized indebtedness, if such financing is likely, and have accounting and fiscal management structures to facilitate financing (see Chapter 7). Likewise, the arrangement must designate an agency or entity with contracting power so that agreements can be authorized with other entities in the overall service structure. Additional responsibilities may be assigned to different groups depending on their historical roles and technical and managerial expertise. Close internal coordination between departments and branches of

Table 2-1 Common institutional arrangements for water reuse Type of Institutional Arrangement Separate Authorities

Production Wastewater Treatment Agency

Wholesaler/Retailer System

Wastewater Treatment Agency

Joint Powers Authority (for Production and Distribution only) Integrated Production and Distribution

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Wholesale Distribution Wholesale Water Agency Wastewater Treatment Agency

Retail Distribution Retail Water Entity Retail Water Entity

Joint Powers Authority

Joint Powers Authority

Retail Water Entity

Water/Wastewater Authority

Water/Wastewater Authority

Water/Wastewater Authority

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local government, along with a range of legal agreements, will be required to ensure a successful reuse program. Examples of institutional agreements developed for water reuse projects are provided in the 2004 guidelines in Chapter 5 and in a case study [USCA-San Ramon]. Finally, the relationship between the water purveyor and the water customer must be established, with requirements on both sides to ensure reclaimed water is used safely. Agreements on rates, terms of service, financing for new or retrofitted systems, educational requirements, system reliability or scheduling (for demand management), and other conditions of supply and use reflect the specific circumstances of the individual projects and the customers served. (See Chapter 7 for a discussion of the development of the financial aspects of water reuse fees and rates.) In addition, state laws, agency guidelines, and local ordinances may require customers to meet certain standards of performance, operation, and inspection as a condition of receiving reclaimed water. However, where a system supplies a limited number of users, development of a reclaimed water ordinance may be unnecessary; instead, a negotiated reclaimed water user agreement would suffice. It is worth noting that in some cases, where reclaimed water is still statutorily considered effluent, the agency’s permit to discharge wastewater—along with the concomitant responsibilities—may be delegated by the agency to customers whose reuse sites are legally considered to be distributed outfalls of the reclaimed water.

2.3 Managing Reclaimed Water Supplies Managing and allocating reclaimed water supplies may be significantly different from the management of traditional water sources. Traditionally, a water utility drawing from groundwater or surface impoundments uses the resource as both a source and a storage facility. If the entire yield of the source is not required, the water is simply left for use at a later date. Yet in the case of reuse, reclaimed water is continuously generated, and what cannot be used immediately must be stored or disposed of in some manner. As a traditional reclaimed water system expands, an increasing volume of water may need to be stored. Depending on the volume and pattern of projected reuse demands, in addition to operational storage considerations, seasonal storage requirements may become a significant design consideration and have a

2012 Guidelines for Water Reuse

substantial impact on the capital cost of the system. While some systems continue to rely on conventional disposal alternatives, the increasing value of reclaimed water is also resulting in more research into practices that provide for increased storage volumes, supplemental water supplies that allow an increased customer base, and improved seasonal management, which together reduce the need for discharges to streams or ocean outfalls. Where water reuse is being implemented to reduce or eliminate wastewater discharges to surface waters, state or local regulations usually require that adequate seasonal storage be provided to retain excess wastewater under a specific return period of low demand. In some cold climate states, storage volumes may be specified according to projected nonapplication days due to freezing temperatures. Failure to retain reclaimed water under the prescribed weather conditions may constitute a violation of an NPDES permit and result in penalties. A method for preparing storage calculations under low-demand conditions is provided in the EPA Process Design Manual: Land Treatment of Municipal Wastewater (EPA, 2006). In many cases, state regulations will also include a discussion about the methods to be used for calculating the storage required to retain water under a given rainfall or low demand return interval. In almost all cases, these methods will be aimed at demonstrating sites with hydrogeologic storage capacity to receive treated effluent for the purposes of disposal. In this regard, significant attention is paid to subsurface conditions as they apply to the percolation of effluent into the groundwater with specific concerns as to how the groundwater mound will respond to effluent loading. Because seasonal storage is such an important factor in maximizing use of reclaimed water, this section provides a discussion of considerations for seasonal storage systems, including surface water storage as well as managed aquifer recharge practices. Another option to maximize the use of reclaimed water is to supplement reclaimed water flows with another water source, such as groundwater or surface water. Supplemental sources, where permitted, can bridge the gap during periods when reclaimed water flows are not sufficient to meet the demands. This practice allows connection of additional users and increases reuse versus disposing of excess reclaimed water. Additionally, operational strategies can be

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implemented to meet peak demands while maximizing the use of reclaimed water during other times of the year. One such strategy is the use of curtailable customers. Brevard County, Fla., has a group of reclaimed water users referred to as “curtailable customers”—customers that maintain an alternative water source (e.g., golf courses that still have irrigation wells as back-up supplies) that can be used during peak demand periods to release reclaimed water demand to meet seasonal peak demands in other areas of their reuse system.

2.3.1 Operational Storage In many cases, a reclaimed water distribution system will provide reclaimed water to a diverse customer base. Urban reuse customers typically include golf courses and parks and may also include commercial and industrial customers. Such is the case in the city of St. Petersburg, Fla., and Irvine Ranch Water District, Calif. These reuse programs, which were previously described in the 2004 guidelines, provide water for cooling, wash-down, toilet flushing, and irrigation (EPA, 2004). Each water use has a distinctive demand pattern and, thereby, impacts the need for storage. While there are systems that operate without seasonal storage, thus limiting their ability to maximize beneficial reuse of the available reclaimed water, the increasing value of reclaimed water is driving better use of operational storage facilities. As a supplement to engineered storage systems, as discussed in Section 2.3.2.4, aquifer storage and recovery (ASR) has tremendous potential to better align reclaimed water availability and with demand, particularly for long periods of time. The potential storage volumes for ASR and the land requirements may be much greater than for conventional engineered systems such as above-ground storage tanks and surface reservoirs. Planners are referred to text in the 2004 guidelines for additional discussion on planning seasonal system storage (EPA, 2004). When considering reclaimed water distribution system storage, planners and engineers should consider the types of users, potential peak demands (daily and seasonal), potential for concurrent peaks, time-of-day restrictions for irrigation, and whether the reclaimed water system will be designed to meet fire protection requirements. Retrofitted dual water systems usually do not include fire protection as the existing potable water system has usually been designed to meet domestic

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requirements, irrigation demands, and concurrent fire flow requirements. By transferring the irrigation demands from the potable water system to the reclaimed water system, the capability of the existing potable water system is extended, and system components for the reclaimed water system can focus on the irrigation and industrial demands. Because there are different peaking factors and time-of-day demands on industrial demands compared to irrigation demands, extended-period simulation models can be used to assist designers in selecting appropriate storage volumes. As discussed in Section 2.2.3, large system users may be required to provide their own onsite storage, allowing multiple large users to be supplied at a constant flow rate over the full 24-hour day. This can decrease pumping and system storage requirements. Some utilities, such as the Loxahatchee River District in Florida, have the ability to curtail deliveries of reclaimed water to large users through telemetry-controlled valves once contractual volumes are met or during periods of extremely high demand. From an operational perspective, maintaining a chlorine residual in the reclaimed water system is as important as maintaining a residual in the potable water system. Public health decisions should control design decisions; maintaining good bacteriological quality in a reclaimed water system where occasional contact with the public is likely dictates monitoring and control measures. This could include chlorine residual analyzers at system storage and booster pump stations to confirm adequate chlorine residuals and systems to add incremental amounts of disinfectant to maintain high water quality. Operational practices that decrease water age by keeping the reclaimed water moving through the system can also improve the quality of the delivered water and decrease system maintenance efforts. Maintaining positive water movement during low-flow/low-demand periods of the year can be accomplished by operating tanks at lower elevations or by having a discharge point at the far ends of the reclaimed water distribution system. In an ideal design, a large customer with continuous demands would be located at the end of the system, ensuring continuous flow through the piping. If there is an opportunity to include discharge to a creek or other water feature near the end of the distribution system, this environmental augmentation can provide a base flow that will assist in maintaining reclaimed water quality in the distribution system. Another alternative is to install air-gap discharges to a sanitary sewer that

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will provide a continuous flow in the reclaimed water transmission main even during periods of low demand. Tank material selection should be based on the material selection criteria applied to the local water system. This guidance is based on the delivery of reclaimed water that is stabilized and meeting statedefined water quality goals. For advanced purification systems that include reverse osmosis (RO), reclaimed water product should be stabilized prior to pumping into the distribution system and storage. Reclaimed water storage tanks are likely to encounter the same public scrutiny as potable storage tanks. When retrofitting an existing system, consider the tank locations already controlled by the utility, and determine if these sites can accommodate a reclaimed water tank. If the potable water tank is located on a high tract of land to minimize tank elevation or pumping head, that same advantage would apply to the reclaimed water system. Tank color may be another common issue to consider. Many states will have labeling requirements, but color choices for the tank structure may not be specified. Maintaining one tank bowl color can provide for a consistent appearance and reduce maintenance cost while reducing customer questions. As with potable storage systems, tank sites should be secure and often are connected into the utility supervisory control and data acquisition (SCADA) system, with water system operators monitoring and controlling the two parallel systems.

2.3.2 Surface Water Storage and Augmentation The reuse of water after discharge into surface water often results in augmentation of potable water supplies where surface water is used for potable water supply. While there are other uses that benefit from surface water storage and augmentation, this section focuses on surface discharge as it relates to unplanned or planned indirect potable reuse, which are also discussed in greater detail in Section 3.7. Unplanned or incidental indirect potable reuse has occurred for decades as utilities pursued the most plentiful, appropriate, and cost-effective options for water supplies. The recent National Academy of Science report, Water Reuse: Potential for Expanding the Nation’s Water Supply through Reuse of Municipal Wastewater described de facto reuse (discussed further in Chapter 3), which is the unplanned reuse of

2012 Guidelines for Water Reuse

treated wastewater that has been discharged to the environment as source water (NRC, 2012). In most cases, the decision to intentionally use or not use a surface water source that included some water that originated as treated wastewater was based on availability and yield of the source water, cost, public acceptance, and public confidence in water treatment processes. The balance of these factors is different for each utility and the communities it serves. In most cases, discharges upstream of surface water sources are designed to meet permit limits and corresponding water quality standards that are protective of beneficial uses downstream of the discharge, including withdrawals for public water supply. In some cases, the incremental addition of various advanced treatment processes to a reclaimed water treatment process will allow the reclaimed water to meet surface water quality standards, thereby making it a viable option to augment water supplies, e.g., the SDWA. The incentive to provide this additional treatment for surface water augmentation may be driven by regulations intended to protect water supplies, but in most cases it is linked to the benefits derived by the discharger or a downstream community seeking to increase the yield of water supplies on which they depend either directly or indirectly. While satisfying the decision factors noted above may be necessary to pursue indirect potable reuse, there are two additional factors that typically control viability of implementation. First, although existing water supplies may be of limited availability and yield, there still must be a means to reap the benefits of withdrawing the additional yield of the augmented water supply via water rights, permits, storage contracts, etc. In other words, a utility can rarely be expected to expend funds in excess of what is required by regulation or law unless there is a recognized benefit to its ratepayers. Second, the public acceptance of indirect potable reuse is of paramount importance but must be based on the specifics of the project and the local community. The following examples illustrate how these key components can play out in project planning and implementation. An often-cited example of surface water augmentation is the Upper Occoquan Service Authority’s (UOSA) discharge into the Occoquan Reservoir in northern Virginia [US-VA-Occoquan]. In this particular case,

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serious water quality issues were caused by multiple small effluent discharges into the reservoir. The Fairfax County Water Authority withdraws water from the Occoquan Reservoir to meet the water supply needs of a large portion of northern Virginia. UOSA was formed in 1971 to address the water quality problem by the same local government entities that relied on the reservoir for their water supply. Therefore, these local governments, and by proxy their residents, received the benefits of the investments in additional wastewater treatment, satisfying the first key component that their water supply was now both protected and augmented. Regarding the second key component, the improvements made a dramatic improvement in the water quality of the reservoir that was readily visible to the general public. Algae blooms, foul odors, low dissolved oxygen (DO) for fish, and other factors were addressed by the regionalization and additional treatment processes, which provided the public with a tangible example of a system that resulted in improved water quality over past practices. Another example is the Gwinnett County, Ga., discharge to Lake Lanier. Lake Lanier is formed by Buford Dam, which is operated by the U.S. Army Corps of Engineers (USACE) on the Chattahoochee River north of Atlanta. Gwinnett County withdraws all of its water from Lake Lanier, as do several other communities around the lake. Given the linkage between water withdrawal from the lake and the desire to return reclaimed water to the lake, the first key component was satisfied by the issuance of a revised state withdrawal permit and amended USACE storage contract that provided credit for the water returned. In this case, the key issues were permitting the discharge and the multiple administrative and legal challenges raised by stakeholders with interests in the lake. Because the focus of these stakeholders was primarily lake quality, discharge limits were made significantly more stringent using anti-degradation regulations as the rationale. In a federal court decision in September 2011, it was determined that Georgia could not use the lake for water supply. Georgia’s neighbors, Alabama and Florida, have argued that Congress never gave Georgia permission to use the federal reservoir as a water source (Henry, 2011 and Section 5.2.3.5).

2.3.3 Managed Aquifer Recharge As our population continues to grow and the associated demand for water increases, alternative water resources may play a greater role in meeting

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water demands. Reclaimed water is a safe and reliable source of supply for replenishing groundwater basins, creating salt water intrusion barriers, and mitigating the negative impacts of subsidence caused by over withdrawal of groundwater. Aquifer recharge has a long history, and there are abundant examples of successfully managed programs. Managed aquifer recharge (MAR) has been successfully applied in California for almost 50 years; the Montebello Forebay Groundwater Recharge Project uses recycled water to recharge the Central Groundwater Basin and provides 40 percent of the total water supply for the metropolitan area of Los Angeles County, Calif. [USCA-Los Angeles County]. Other MAR projects have been implemented to aid in maintaining a salt balance in water supply aquifers, as demonstrated in a case study on the Santa Ana River Basin [US-CA-Santa Ana River]. In Arizona, the Groundwater Management Act allows users to store recharged water and sell the associated water rights. This led to the first-ever auction of reclaimed water rights in Prescott Valley. The ability to bank recharged reclaimed water provided the versatility necessary for the auction [US-AZ-Prescott Valley]. In Mexico City, reclaimed water is being used to recharge the local aquifer, which is overdrawn by 120 percent, leading to the subsidence of the soil in some places at a rate of up to 16 in/yr (40 cm/yr) [Mexico-Mexico City]. (National Water Commission of Mexico, 2010). MAR systems may be described in terms of their five major components: a source of reclaimed water, a method to recharge, sub-surface storage, recovery of the water, and the final use of the water. One of the key considerations in MAR is managing the travel time of reclaimed water before it is recovered for use. As a result, the identification, selection, and testing of environmentally-acceptable tracers for measuring travel times of reclaimed water and its constituents in recharge systems has been the subject of recent research. In the research report Selection and Testing of Tracers for Measuring Travel Times in Natural Systems Augmented with Treated Wastewater Effluent (WRRF, 2009), a summary of literature related to conservative and surrogate tracers for reclaimed water constituent transport in the subsurface is provided along with the materials and results from tracer experiments on three common recharge systems augmented with reclaimed water, information on the

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process for regulatory approval of the use of tracers for reclaimed water recharge systems, and field methods for conducting tracer tests. Reclaimed water can be directly or indirectly used after sub-surface storage. Some systems both directly and indirectly use reclaimed water when demand for irrigation is high and recharge water for future indirect use when demand for irrigation is low. The two primary types of groundwater recharge are surface spreading and direct injection. Vadose zone injection wells have been increasing in use as this technology has become established in recent years. Figure 2-5 illustrates these recharge methods. Direct injection wells may also be used as dual-purpose ASR wells for both recharging and recovering stored water. The recharge method will depend on the aquifer type and depth and on the aquifer characteristics, which impact the ability to recharge water into the storage zone and later recover that water. The use of recharge basins and vadose zone injection wells is restricted to unconfined aquifers, while direct injection systems may be used in both unconfined and deeper confined aquifer systems.

VADOSE ZONE INJECTION WELL

RECHARGE BASIN

DIRECT INJECTION WELL

Vadose Zone

Unconfined Aquifer Aquitard Confined Aquifer

Figure 2-5 Commonly used methods in managed aquifer recharge

There are many site-specific variables that affect the design and selection of the most appropriate MAR system for a specific application. As shown in Figure 2-6, the first critical question is “what aquifer is being considered for use in the MAR system?” If a confined aquifer is being considered, then direct injection is the only feasible alternative; direct injection may include either single-use injection wells or the dual-purpose wells used in ASR systems. If the goal of a groundwater recharge project is to provide short-term

2012 Guidelines for Water Reuse

storage and the water must be recovered quickly, then ASR systems might be the only feasible alternative. If an existing distribution and well system may be utilized as part of an ASR system, then dual-purpose direct injection wells might be the best choice. If an unconfined aquifer is being considered, there are no constraints on the choice of recharge method.

Is this aquifer confined or unconfined?

If Unconfined No constraint on recharge method.

If Confined Direct injection must be used.

What is the depth of the groundwater?

If less than 330-660 ft, direct injection may be cost competitive with surface recharge.

If greater than 330-660 ft, surface recharge should be considered. Is cost-effective land available at an appropriate location?

If no, vadose zone injection wells may be appropriate.

If yes, surface recharge basins may be appropriate.

Figure 2-6 Sample decision tree for selection of groundwater recharge method

For unconfined aquifers, as the depth to groundwater increases, the cost of direct injection wells increases; therefore, the effect of depth should be evaluated for each situation. Land price, location, and availability are also key considerations. Potential negative impacts from rising groundwater levels, including groundwater mounding, must also be considered.

2.3.3.1 Water Quality Considerations Depending on the method and purpose of groundwater recharge, most states require either a minimum of secondary treatment with or without additional filtration for groundwater recharge. State Underground Injection Control programs and Sole Source Aquifer Protection are included under Sections 1422 of the SDWA, which provides safeguards so that aquifer recharge and ASR

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wells do not endanger current and future underground sources of drinking water. There is currently no specific requirement for nutrient removal, but lower effluent nutrient concentrations required for pointsource discharges could meet strict nutrient groundwater recharge requirements, such as the 0.5 mg/L ammonia limit in Miami-Dade County for the South District Water Reclamation Plant (SDWRP), without additional treatment. Additionally, the California Draft Regulations for Groundwater Replenishment with Recycled Water proposes a 10 mg/L total nitrogen limit for recycled water (California Department of Public Health [CDPH], 2011). Nutrient removal at the wastewater plant is also thought to remove N-nitrosodimethylamine (NDMA) precursors, reducing the potential formation of NDMA. Generally, direct injection requires water of higher quality than is required for surface spreading because of the absence of a vadose zone and/or shallow soil matrix treatment afforded by surface spreading, as discussed in Chapter 6. In addition, higher-quality water is needed to maintain the hydraulic capacity of the injection wells, which can be affected by physical, biological, and chemical clogging. Water quality parameters are typically measured at the end of the treatment plant, but some agencies, such as Florida’s Miami-Dade Department of Environmental Resources Management (DERM), allow projects to meet the requirements at the nearest ecological receptor. In many cases, wells used for injection and recovery of reclaimed water are classified by EPA as Class V injection wells, and some states, including California and Florida, require that the injected water must meet drinking water standards prior to injection, depending on the native quality of water in the aquifer being recharged. Typical water quality parameters used for regulating recharge include total nitrogen, nitrate, nitrite, total organic carbon (TOC), pH, iron, total coliform bacteria, and others, depending on the use of the aquifer. Other water quality parameters can be used to estimate potential well corrosion or fouling, including calculated values such as the Langelier Saturation Index (LSI), the Silt Density Index (SDI), and the Membrane Fouling Index (MFI). Information and global case studies on specific treatment technologies to address microbial and chemical contaminants for MAR applications are available in Water Reclamation Technologies for Safe Managed Aquifer Recharge (Kazner et al., 2012).

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Other criteria specific to the quality of the reclaimed water, groundwater, and aquifer matrix must also be taken into consideration. These include possible undesirable chemical reactions between the injected reclaimed water and groundwater, iron precipitation, arsenic leaching, ionic reactions, biochemical changes, temperature differences, and viscosity changes. Most clogging problems are avoided by proper pretreatment, well construction, and operation (Stuyfzand, 1998). Hydrogeochemical modeling should be performed to confirm compatibility of the recharge water and the aquifer matrix. In some areas, such as South Florida and Southern California, naturallyoccurring arsenic-containing minerals in the aquifer matrix may leach into the groundwater due to changes in oxidation-reduction potential (ORP) during injection, storage, and recovery. Arsenic in recovered water has been detected or is a significant concern based on area ASR projects. Approaches to minimizing arsenic levels and other trace inorganic leaching/transport can include controlling the pH and matching the ORP of the recharge water with the ORP of the ambient groundwater. For direct injection to a highly permeable aquifer, such as the Biscayne Aquifer in South Florida, additional nutrient limits that are stricter than those required for typical direct injection may be set. The nutrient requirements address the potential impacts to nearby surface waters, such as rivers, lakes, canals, and wetlands that are hydrologically connected and supported by the aquifer. For the SDWRP, DERM has a very low ammonia requirement (0.5 mg/L) and includes phosphorus removal in its antidegradation water quality requirements.

2.3.3.2 Surface Spreading Surface spreading is the most widely-used method of groundwater recharge due to its high loading rates with relatively low maintenance requirements. At the spreading basin, the reclaimed water percolates into the soil, consisting of layers of loam, sand, gravel, silt, and clay. As the reclaimed water filters through the soil, these layers allow it to undergo further physical, biological, and chemical purification through a process called Soil Aquifer Treatment (SAT); ultimately, this water becomes part of the groundwater supply. SAT systems require unconfined aquifers, vadose zones free of restricting layers, and soils that are coarse enough to allow for sufficient infiltration rates but fine enough to provide adequate filtration. A summary and discussion of the removal mechanisms for pathogens, organic carbon, contaminants of concern, and nitrogen

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Chapter 2 | Planning and Management Considerations

during SAT are provided in Chapter 6. These mechanisms are important when spreading basins and analogous systems, such as bank filtration, are used; this treatment also occurs to a varying extent during ASR, vadose zone injection, and direct injection. Though management techniques are site-specific and vary accordingly, some common principles are practiced in most spreading systems. The three main engineering factors that can affect the performance of surface spreading systems are reclaimed water pretreatment, site characteristics, and operating conditions (Fox, 2002). Reclaimed Water Pretreatment. Municipal wastewater typically receives a minimum of conventional secondary treatment, but may also receive filtration followed by disinfection (e.g., chlorination) prior to groundwater recharge. Some utilities are beginning to further treat the reclaimed water with microfiltration, RO, and ultraviolet (UV) disinfection prior to recharge into potable water aquifers. For reclaimed water that is spread in groundwater basins, the soil itself provides additional treatment to purify the water through SAT. Reclaimed water pretreatment directly impacts the performance of a SAT system. While RO processes provide high reclaimed water quality, the reject brine waste streams from this process may be difficult to dispose. Site Characteristics. Local geology and hydrogeology determine the site characteristics for a surfacespreading operation. Site selection is dependent on a number of factors, including suitability for percolation, proximity to conveyance channels and/or water reclamation facilities, and land availability. Design options for spreading grounds are limited to the size and depth of the basins and the location of production wells. The subsurface flow travel time is affected by the well locations. System Operation. For surface spreading to be effective, the wetted surfaces of the soil must remain unclogged to maximize infiltration, and the quality of the reclaimed water should not inhibit infiltration. Spreading basins are typically operated under a wetting/drying cycle designed to optimize inflow and percolation and discourage the presence of vectors. Spreading basins can be subdivided into an organized system of smaller basins that can be filled or dried alternately to allow maintenance in some basins while others are being used.

2012 Guidelines for Water Reuse

Spreading basins should be managed to avoid nuisance conditions, such as algae growth and insect breeding in the basins. This is typically accomplished by rotating a number of basins through wetting, draining, and drying cycles. Cycle length is dependent on soil conditions, the development of a clogging layer, and the distance to the groundwater table. Algae can clog the bottom of basins and reduce infiltration rates. Algal growth can be minimized by upstream nutrient removal or by reducing the detention time of the reclaimed water within the basins, particularly during summer periods when algal growth rates increase due to solar intensity and increased temperature. Periodic maintenance, which involves cleaning the basin bottom by scraping the top layer of soil, is used to prevent clogging. Disking of the basin to break up surface clogging is generally not used as it forces finer clay particles deeper into the soil column. When a clogging layer develops during a wetting cycle, infiltration rates can decrease to unacceptable levels. The drying cycle allows for the aeration and drying of the clogging layer and the recovery of infiltration rates during the next wetting cycle.

2.3.3.3 Injection Wells Methods for recharging groundwater using injection wells can include injection either into the vadose zone or directly into the aquifer. Each injection method has its own unique applicability and requirements, which vary with location, quantity and quality of source water, and hydrogeology of the vadose zone and target aquifers. While direct injection wells are more expensive than vadose zone wells, the control of where the water is injected minimizes risks associated with lost water. Direct injection wells can also be cleaned and redeveloped, which reduces fouling and lengthens the life of the wells. A summary of vadose zone and direct-injection well construction and operation is presented in Table 2-2, including the main advantages and disadvantages for each of the recharge methods. Vadose zone wells are the least expensive injection method, but they have a limited life and must be replaced periodically. Direct injection wells are more costly, can be maintained for a longer life, and allow water to be directly and quickly recharged into the targeted aquifer.

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Chapter 2 | Planning and Management Considerations Table 2-2 Comparison of vadose zone and direct injection recharge wells Recharge Method

Main Advantages

Main Disadvantages

- Suitable for unconfined aquifers - Bypass low permeability layers - Decreased travel time to aquifers versus Vadose Zone Wells

surface spreading

- Lower cost - SAT benefits to water quality - May allow smaller setback from extraction wells

Groundwater Injection Wells

-

Can target specific aquifers and locations Benefits groundwater levels immediately Wells can be cleaned and redeveloped Can be maintained for a longer life

Vadose Zone Injection. Vadose zone injection wells for groundwater recharge with reclaimed water were developed in the 1900s and have been used primarily where aquifers are very deep and construction of a direct-injection well is difficult and expensive. A vadose zone well is essentially a dry well, installed in the unsaturated zone above the permanent water table. These wells typically consist of a large-diameter borehole, sometimes with a casing or screen assembly, installed with a filter pack. The well is used to transmit recharge water into the ground, allowing water to enter the vadose zone through the well screen and filter pack and percolate into the underlying water table. Creating this conduit into the ground can be advantageous where surficial soils or the shallow subsurface contain clay layers or other lowpermeability soils that impede percolation deep into the ground. Vadose zone wells allow recharge water to bypass these layers, reaching the water table faster and along more direct pathways. Typical vadose zone injection wells vary in width from about 2 ft (0.5 m) up to 6 ft (2 m) in diameter and are drilled 100 to 150 ft (30 to 46 m) deep. A vadose zone injection well is backfilled with porous media, and a riser pipe is used to allow water to enter at the bottom of the wells to prevent air entrainment. An advantage of vadose zone injection wells is significant cost savings when compared to direct-injection wells. Although the infiltration rates of vadose zone wells are often similar or slightly better as compared to directinjection wells, they cannot be backwashed, and a severely clogged well may be permanently destroyed. Therefore, reliable pretreatment is considered essential to maintaining performance of a vadose zone

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- Inability to rehabilitate clogged wells - Decreased certainty of migration pathways

- Requires operation to avoid air entrainment

- Deeper wells needed to penetrate deep clay layers

- New wells required periodically - Greater risk of water loss - Wells can be costly to install and maintain

- Periodic pumping required to maintain capacity

- Foot valves may be required to minimize air entrainment

injection well. Maintenance of a disinfection residual is critical if the water has not been treated by RO. Because of the considerable cost savings associated with vadose wells as compared to direct injection wells, the estimated 5-year life cycle for a vadose injection well can still make it an economical choice. And, because vadose zone injection wells allow for percolation of water through the vadose zone and flow into the saturated zone, it should be expected that some water quality improvements similar to soil aquifer treatment would be achieved (see Chapter 6 for further discussion). The number of vadose zone injection wells is dependent on the recharge capacity of the soil matrix. Recharge capacities can be estimated from test wells and infiltration tests. The head required to drive the water into the ground is influenced by the lithology and hydraulic conductivity (permeability) of the soil in the vadose zone. Because the movement of the water is highly dependent on localized features, such as clay layers or low-permeability lenses, movement is difficult to predict. Capture of the recharge water within the aquifer for extraction is also less certain than with direct injection, and vadose zone projects are at greater risk of water loss. Vadose zone injection facilities were constructed as part of the city of Scottsdale’s Water Campus project northeast of downtown Phoenix, Ariz. The project has 35 active injection wells (with 27 back-up wells) with a capacity of about 400 gpm each. The wells were constructed to a depth of 180 to 200 ft with the aquifer water level approximately 1,200 ft below ground surface (bgs). Vadose zone injection wells of similar

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design are also used by the cities of Gilbert and Chandler, Ariz. Reuse projects in other areas, such as the Seaside Basin in the Monterrey Bay area of California, have also considered the use of vadose zone wells because of the depth to groundwater (300+ ft bgs). According to groundwater modeling estimates, it would take almost 300 days for the water recharged in the vadose zone to reach the top of the aquifer. Because of clay layers and other low- permeability soil lenses, there is minimal control of where the recharged water enters the underlying aquifer and at what rate. Rapid Infiltration Trenches. Rapid infiltration trenches (RITs) are not vadose zone wells, but are similar in that recharge water is discharged into a media-filled “hole” or trench. Unlike the verticallyconstructed vadose zone well, however, RITs are long, horizontal trenches excavated into the soil and filled with media. A horizontal, perforated pipe conveys the water into the RIT where it percolates into the underlying soil. RITs can be excavated into the vadose zone where the groundwater is deep, or into the aquifer where groundwater levels are close to the surface. Because RITs are not true wells, specialty contractors are not required, and the costs can be less than either vadose zone or direct-injection wells. Direct Injection. Direct-injection systems involve pumping recharge water directly into either a confined or unconfined aquifer. Direct injection is used where space or hydrogeological conditions are not conducive to surface spreading; such conditions might include unsuitable surface/near-surface soils of low permeability, unfavorable topography for construction of basins, the desire to recharge confined aquifers, or scarcity of land. Direct injection is also an effective method for creating barriers against saltwater intrusion in coastal areas and for development of ASR systems using dual-purpose wells. In designing a directinjection well system, it is critical to fully characterize the target aquifer and surrounding confinement hydraulics that will affect migration of the reclaimed water. Additionally, water quality within the reuse system and the target aquifer must be balanced along with the needs of the end user in development of a direct-injection system. A direct-injection well is drilled into the targeted aquifer, discharging recharge water at a specific depth within the aquifer. Direct-injection wells are similar to extraction wells in that they have a borehole and

2012 Guidelines for Water Reuse

casing and may have screens, granular media around the well, and a drop pipe into the well. The diameter of the well depends on required flow and the ability of the aquifer to move the water. Screened wells are required in unconsolidated formations whereas open-hole construction is typically used in rock formations. The injection well can be designed to target specific aquifers or specific portions of an aquifer that are most suitable for injection. Typical direct-injection wells vary in diameter from about 12 to 30 in (30 to 76 cm), and depths vary from less than 100 ft to more than 1,500 ft (30 to 470 m) in certain applications. Ideally, an injection well will recharge water at the same rate as it can pump yield water; however, conditions are rarely ideal. Injection/withdrawal rates tend to decrease over time, and although clogging can easily be remedied in a surface spreading system by scraping, drying, and other methods, remediation in a direct-injection system can be costly and time consuming, depending on the nature and severity of clogging. The most frequent causes of clogging are accumulation of organic and inorganic solids, biological and chemical precipitates, and dissolved air and gases from turbulence. Low concentrations of suspended solids (1 mg/L) can clog an injection well. Even low concentrations of organic contaminants can cause clogging due to bacteriological growth near the point of injection. Typical remediation of a clogged well is by mechanical means or chemical injection of acids and/or disinfectants. Treatment of organics can occur in the groundwater system with time, especially in aerobic or anoxic conditions (Gordon et al., 2002; Toze and Hanna, 2002). Therefore, the location of the direct injection wells in relation to the extraction well is critical to determining the flow-path length and residence time in the aquifer, as well as the mixing of recharge water with native groundwater. When recharge water has been treated by RO, improvements in water quality are not expected. There have been several cases where direct-injection systems with wells providing significant travel time have allowed for the passage of NDMA and 1,4-dioxane into recovery wells, even though treatment processes included RO. Additional treatment of reclaimed water is now required to control these contaminants. These trace organic compounds (TrOCs) have not been observed in soil aquifer treatment systems using spreading basins where microbial activity in the subsurface is stimulated. It is uncertain whether RO water discharged into a vadose

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zone well will support biological activity and additional treatment; at the Scottsdale Water Campus, attenuation of NDMA during sub-surface transport has been limited with RO-treated water and vadose zone injection wells. Direct-injection wells have been used for Orange County Water District’s (OCWD) Talbert Gap Barrier with water supplied by the Groundwater Replenishment System (GWRS), for the Dominguez Gap Barrier with water supplied by the West Basin Municipal Water District’s El Segundo facilities, and for the Alamitos Barrier with water supplied in part by the Water Replenishment District’s Leo J. Vander Lans Water Treatment Facility (LVLWTF) [US-CA-Vander Lans]. Direct-injection wells were also proposed for Miami-Dade Water and Sewer Department’s SDWRP [US-FL-Miami So District Plant].

2.3.3.4 Recovery of Reclaimed Water through ASR ASR allows direct recovery of reclaimed water that has been injected into a subsurface formation for storage. ASR can be an effective management tool to provide reclaimed water storage, minimizing seasonal fluctuations in supply and demand, by allowing storage during the wet season when demand is low and recovery of water during dry periods when demand is high. Because the potential storage volume of an ASR system is essentially unlimited, it is expected that these systems will offer a solution to the shortcomings of the traditional, engineered storage techniques. ASR was considered as part of the Monterey County, Calif., reuse program to overcome seasonal storage issues associated with an irrigation-based project. In the United States, reclaimed water ASR projects are currently operating in Arizona, Florida, and Texas (Pyne, 2005; Shrier 2010). Internationally, the only operating ASR systems identified in literature are located in Australia. While ASR is gaining interest, there are considerations for operation of these systems. Federal Underground Injection Control (UIC) rules do not allow the injection of any fluid other than water meeting drinking water standards into an underground source of drinking water (USDW), which is defined as having a total dissolved solids concentration of less than 10,000 mg/L (EPA, 2001). Section 1453 of the 1996 amendments to the SDWA outlines a Source Water Quality Assessment to achieve maximum public health

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protection. This could require reclaimed water to be treated with advanced treatment and disinfection processes, such as RO and UV light with ozone or peroxide, to not only meet drinking water standards but also to address state-specific regulations for trace organics and pathogens. Therefore, many existing reclaimed water ASR projects inject into portions of aquifers beneath the USDW (i.e., into brackish water aquifers). However, there still must be good vertical confinement between the injection zone and the base of the USDW to prevent upward vertical migration of the injected reclaimed water into the USDW. For reclaimed water ASR projects injecting into nonpotable aquifers (total dissolved solids [TDS] >10,000 mg/L), the recovery efficiencies are usually less than for other ASR projects injecting into the USDW. In addition, potentially undesirable geochemical reactions between the injected fluid and the aquifer matrix must be considered. Unlike other MAR systems, there is a buffer zone where reclaimed water and native groundwater blend in a manner that is distinctly different from other systems. Pathogens and organic contaminants in reclaimed water complicate the use of ASR for reclaimed water storage and recovery, and high levels of treatment and disinfection are needed to implement reclaimed water ASR. ASR Water Quality Considerations. The primary contaminants in reclaimed water that affect ASR projects include nutrients and metals, pesticides, endocrine disruptor compounds, pharmaceuticals and personal care products, and microbes (WRRF, 2007b). SDWA describes the essential steps for every community to inventory known and potential sources of contamination within their drinking water sources. Nutrients and most bacteria are usually removed in advanced biological wastewater treatment processes. While most large pathogens are not a concern in most MAR systems, the reversal of flow in ASR systems can release materials that are normally removed. These same treatment processes are also typically used to remove the other recalcitrant groups of contaminants listed above. If the TOC concentrations are elevated and chlorine is used for disinfection, disinfection by-products (DBPs) such as trihalomethanes, haloacetic acids, and NDMA can be of concern. A more in-depth discussion of these source water quality concerns is presented in Prospects for Managed Underground Storage of Recoverable Water and Reclaimed Water Aquifer

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Storage and Recovery: Potential Changes in Water Quality (NRC, 2008 and WRRF, 2007b). According to the 2007 WateReuse Research Foundation (WRRF) study referenced above, 13 U.S.based reclaimed water ASR projects and three international reclaimed water ASR projects were identified in various phases of development and implementation (Table 2-3). Two additional projects in Florida were being tested as of 2012; the Collier County and Naples projects are also shown in Table 2-3. The reclaimed water source for all 18 ASR projects will meet advanced wastewater treatment levels with disinfection. Additionally, two of the facilities in the United States (Fountain Hills and Scottsdale, Ariz.) and one project in Kuwait (Sulaibiya) are/will be using advanced filtration technologies, such as microfiltration (MF) or MF/RO, to improve water quality prior to injection. While there are specific water quality requirements for ASR, regulatory agencies also may limit the quantity of reclaimed water used for a groundwater recharge project, also referred to as the reclaimed water contribution (RWC). The RWC is calculated by dividing the volume of reclaimed water recharge by the total volume of water recharge. Other sources of water recharge, which serve to dilute the reclaimed water, must not be of wastewater origin and can include imported water, local water supply, and, potentially, subsurface flow. The inclusion of subsurface flow in the basin recharged by the Inland Empire Utilities Agency in Chino, Calif. has virtually eliminated the need for other sources of water recharge. The RWC may be set by the regulatory agency and can vary depending on the level of effluent treatment, the type of recharge, and project history. Monitoring. Recharge projects are strictly regulated and subject to complex water quality monitoring and compliance programs that assess all the waters used for recharge of the groundwater system to ensure the protection of human health and the environment. Additionally, water reclamation plant performance reliability is ensured through various in-plant control parameters, redundancy capabilities, and emergency operation plans. This is discussed in greater detail in Section 2.3.4.

2012 Guidelines for Water Reuse

The use of recycled water to recharge groundwater via surface spreading or direct injection has been successfully applied in California for almost 50 years [US-CA-Los Angeles County]. As the future supply of surface water continues to diminish and our population continues to grow, alternative water resources must increase to meet water demands. Subsurface Geochemical Processes. Adverse geochemical reactions can occur in the storage zone due to differences in water quality between the injected fluid and native water quality (Mirecki, 2004; NRC, 2008). Although relatively uncommon in ASR projects, geochemical reactions can occur that result in dissolution and clogging of the aquifer matrix in the storage zone. The most notable reaction is the oxidation of arsenopyrite, a naturally-occurring mineral in aquifers. When this mineral is oxidized, arsenic is released into the stored water (at concentration in excess of the drinking water maximum contaminant level (MCL) of 10 µg/L) due to differences in ORP between the injected fluid and native groundwater. Many source waters (potable, surface, and reclaimed water) have an elevated ORP (+millivolts) and DO (>2 to 3 mg/L) concentrations relative to confined aquifers and deep portions of unconfined aquifers (-millivolts and <0.5 mg/L). The oxidized source waters can react with the aquifer matrix, which is in equilibrium under reduced conditions, changing the hydrogeochemistry of the stored and recovered water. Different technologies that can adjust the ORP and DO of the recharge waters closer to that of the native water before injection into confined aquifers have been developed (Bell et al., 2009; Entrix, 2010). Recent research by USACE suggests that treated surface water initially causes arsenic in the aquifer matrix to leach into the stored and recovered water, but it is later readsorbed in the presence of naturally high iron and TOC concentrations in the source water (Mirecki, 2010). The conclusions in this study suggest that similar water quality conditions that can lead to the precipitation of arsenic occur in reclaimed water. Additional information on the state of the practice of ASR using reclaimed water is provided in the WRRF report, Reclaimed Water Aquifer Storage and Recovery: Potential Changes in Water Quality (WRRF, 2007b).

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Table 2-3 Operational status and source water treatment for reclaimed water ASR projects State or Country Arizona

City or County Chandler

Operation Status Full Operation

Arizona

Fountain Hills

Full Operation

Arizona

Scottsdale

Full Operation

Florida Florida Florida Florida Florida Florida Florida Florida Florida Florida Florida Florida Florida Texas Australia Australia

Cocoa Englewood Hillsborough County Clearwater Lehigh Acres Manatee County Collier County Naples Oldsmar Pinellas County St. Petersburg Tarpon Springs Sarasota County El Paso Adelaide (Bolivar) Willunga

Testing Full Operation Terminated Terminated Testing Testing Testing Testing Permitting Feasibility/Planning Testing Feasibility/Planning Construction Full Operation Full Operation Testing

Sulaibiya

Feasibility/Planning

Kuwait

Reclaimed Water Treatment Level Advanced treatment with UV disinfection Conventional secondary treatment /microfiltration/unknown method of disinfection Advanced treatment/microfiltration/RO/Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection NA NA Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment/ozone disinfection Advanced treatment with Cl2 disinfection Advanced treatment with Cl2 disinfection Advanced treatment/RO/unknown method of disinfection

(Source: Updated data from WRRF, 2007b) Cl2 means chlorine NA means not applicable

2.3.3.5 Supplementing Reclaimed Water Supplies Another option to maximize the use of reclaimed water for irrigation is to supplement reclaimed water flows with other sources, such as groundwater or surface water. Supplemental sources, where permitted, can bridge the gap during periods when reclaimed water flows are not sufficient to meet the demands, Supplementing reclaimed water flows allows connection of additional users and increases reuse overall versus disposing of excess reclaimed water. Incremental use of supplemental supplies can result in a significant return in terms of reclaimed water usage versus supplemental volumes. An example of a utility that developed supplemental supplies is the city of Cape Coral, Fla. There are approximately 400 mi of canal systems within the city. Of these, approximately 295 mi are considered freshwater and about 105 mi are brackish water. In addition, within these canals, approximately 27 watercontrol structures (weirs) have been designed and placed to control canal flows. Supplemental water from

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this canal system has been used since the early 1990s to bridge the gap between reclaimed water supply and demands. Today, Cape Coral’s reclaimed water program (“Water Independence for Cape Coral” or WICC) provides supplemented reclaimed water to almost 38,000 residences for irrigation. The city has implemented a major initiative over the last decade to install automated flow controls on all existing weirs, allowing the city to control freshwater canal levels and optimize the hydro period to mimic more natural flow patterns. These upgrades allow the city to store considerably more water in the existing canals. ASR is also planned to store excess surface water. Upon completion of the project, the city will be able to store an additional 1 billion gallons (3.8 MCM) of freshwater in the canals during dry periods and in ASR wells during wet periods. In addition to supplementing reclaimed water supplies, alternative source waters can be used to replace the demands for reclaimed water. Discussion of alternative water sources as part of an integrated water management approach is provided in Section 2.4

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Chapter 2 | Planning and Management Considerations

2.3.4 Operating a Reclaimed Water System In order to protect public health and enhance customer satisfaction and confidence, water of a quality that is safe and suitable for the intended end uses must be reliably produced and distributed, regardless of the source water. AWWA published the third edition of its Manual of Water Supply Practices M-24, which discusses planning, design, construction, operation, regulatory framework, and management of community dual-water systems (AWWA, 2009). In addition to the materials discussion in that manual, a brief discussion of the importance and considerations for well-designed quality assurance/quality control (QA/QC) and monitoring programs is provided here.

2.3.4.1 Quality Control in Production of Reclaimed Water A high standard of reliability, similar to water treatment plants, is required at wastewater reclamation plants. An array of design features and non-design provisions can be employed to improve the reliability of the separate elements of a water reclamation system and the system as a whole. Backup systems are important in maintaining reliability in the event of failure of vital components, including the power supply, individual treatment units, mechanical equipment, the maintenance program, and the operating personnel. Federal guidelines identify the following factors that are appropriate to consider for treatment operations (EPA, 1974):

Design Factors: 

Duplicate dual feed sources of electric power



Standby on-site power for essential plant elements



Multiple process units and equipment



Holding tanks or basins to provide for emergency storage of overflow and adequate pump-back facilities



Flexibility of piping and pumping facilities to permit rerouting of flows under emergency conditions



Dual chlorination systems



Automatic residual control

2012 Guidelines for Water Reuse



Instrumentation and control systems for online monitoring of treatment process performance and alarms for process malfunctions



Supplemental storage and/or water supply to ensure that the supply can match user demands

Other Factors: 

Preliminary project planning and engineering report to indicate reliability compliance



Effective monitoring program



Effective maintenance and process control program



Operator certification to ensure that qualified personnel operate the water reclamation and reclaimed water distribution systems



A comprehensive QA program to ensure accurate sampling and laboratory analysis protocol



A comprehensive operating protocol that defines the responsibilities and duties of the operations staff to ensure reliable production and delivery of reclaimed water



A strict industrial pretreatment program and strong enforcement of sewer-use ordinances to prevent illicit dumping of hazardous materials— or other materials that may interfere with the intended use of the reclaimed water—into the collection system

Additional discussion of many of these reliability features is discussed in Section 3.4.3 of the 2004 EPA Guidelines for Water Reuse. Many states have incorporated procedures and practices into their reuse rules and guidelines to enhance the reliability of reclaimed water systems, including inline automatic diversion valves when reclaimed water quality does not meet monitoring requirements for chlorine residual and turbidity.

2.3.4.2 Distribution System Safeguards for Public Health Protection in Nonpotable Reuse As described in Chapters 3 and 4, the level of treatment required for reclaimed water depends on the intended use. Where water reuse applications are designed for indirect or direct potable reuse, treatment is designed to achieve the level of purity required for

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Chapter 2 | Planning and Management Considerations

potable reuse. Where reclaimed water is to be used in nonpotable applications, water quality must be protective of public health, but need not be treated to the quality required for potable reuse. In addition to appropriate water quality requirements, other safeguards must be employed to protect public health in nonpotable reuse.

Protection (FDEP) requires all components to be tagged or labeled (bearing the words “Do not drink” in English and “No beber” in Spanish, together with the equivalent standard international symbol) to warn the public and employees that the water is not intended for drinking (FDEP, 2009). Figure 2-7 shows a typical reclaimed water advisory sign and pipe coloring.

Where reclaimed water is intended for nonpotable reuse, the major priority in design, construction, and operation of a reclaimed water distribution system is the prevention of cross-connections. A crossconnection is a physical connection between a potable water system used to supply water for drinking purposes and any source containing nonpotable water through which potable water could be contaminated. Another major objective is to prevent improper or inadvertent use of reclaimed water as potable water. To protect public health from the outset, a reclaimed water distribution system should be accompanied by the following protection measures: 

Establish that public health is the overriding concern



Devise procedures and regulations to prevent cross-connections and misuse, including design and construction standards, inspections, and operation and maintenance staffing



Ensure the physical separation of the potable water, reclaimed water, sewer lines, and appurtenances in design and construction



Develop a uniform system to mark nonpotable components of the system



Devise procedures for disconnection) of service

approval

all (and



Establish and train special staff members to be responsible for operations, maintenance, inspection, and approval of reuse connections



Provide for routine monitoring and surveillance of the nonpotable system



Prevent improper or unintended use of nonpotable water through a proactive public information program

Some states specify the type of identification required. For example, the Florida Department of Environmental

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Figure 2-7 Typical sign complying with FDEP signage requirements (Photo credit: Lisa Prieto)

The type of messaging on advisory signs must comply with state guidelines and regulations and be chosen carefully to support public awareness. Chapter 8 discusses some of the issues surrounding messaging about water reuse. One specific issue for signage that includes the message “do not drink” is the potential long-term public perception that reclaimed water cannot be safe for drinking. If a city may want to introduce potable reuse in the future, the choice of messaging for signage of nonpotable reuse applications is all the more critical. In addition to advisory signs and coloring, the valve covers for nonpotable transmission lines should not be interchangeable with potable water covers. For example, the city of Altamonte Springs, Fla., uses square valve covers for reclaimed water and round valve covers for potable water. Blow-off valves should be painted and carry markings similar to other system piping. Irrigation and other control devices should be marked both inside and outside. Any constraints or special instructions should be clearly noted and placed in a suitable cabinet. If fire hydrants are part of the system, they should be painted or marked, and the stem should require a special wrench for opening.

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All piping, pipelines, valves, and outlets must be colorcoded, or otherwise marked, to differentiate reclaimed water from domestic or other water (FDEP, 2009). FDEP requires color coding with Pantone Purple 522C using different methods, depending on the size of the pipe (FDEP, 2009). Pipe coloring can be integrated into the material or added externally with a polyethylene vinyl wrap, vinyl adhesive tape, plastic marking tape (with or without metallic tracer), or stenciling, as shown in Figure 2-8. The IAPMO publishes the Uniform Plumbing Code, a document that many state and local governments use as a model when they approve their own plumbing codes. An alternate code is the IPC distributed by the ICC.

Figure 2-8 Reclaimed water pumping station, San Antonio, Texas (Photo credit: Don Vandertulip)

Permitting and Inspection. The process to permit water reclamation and reuse projects differs from state to state; however, the basic procedures generally include plan and field reviews followed by periodic inspections of facilities. This oversight includes inspection of reclaimed water generators, distributors and, in some cases, end users. Additional guidance on permitting and inspection is provided in the Manual of Water Supply Practices M-24 (AWWA, 2009). Piping at the site of reclaimed water use may be controlled by local plumbing code, and advance coordination between utility and local plumbing departments is advised.

2.3.4.3 Preventing Improper Use and Backflow Several methods can be used to prevent inadvertent or unauthorized connection to a reclaimed water system. The Irvine Ranch Water District, Calif., mandates the use of special quick-coupling valves with

2012 Guidelines for Water Reuse

an Acme thread key for on-site irrigation connections. This type of valve is not used in potable water systems, and the cover on the reclaimed water coupler is different in color and material from that used on the potable system. Hose bibs are generally not permitted on nonpotable systems because of the potential for incidental use and possible human contact with the reclaimed water. Florida regulations (FDEP, 2009) allow below-ground bibs that are either placed in a locking box or require a special tool to operate. Where the possibility of cross-connection between potable and reclaimed water lines exists, backflow prevention devices should be installed on-site when both potable and reclaimed water services are provided to a user. The backflow prevention device is placed on the potable water service line to prevent potential backflow from the reclaimed water system into the potable water system if the two systems are illegally interconnected. Accepted methods of backflow prevention vary by state, but may include: 

Air gap



Reduced-pressure principal backflow prevention assembly



Double-check valve assembly



Pressure vacuum breaker



Atmospheric vacuum breaker

In addition to discussion of backflow prevention in Section 3.6.1 of the 2004 EPA Guidelines for Water Reuse, additional guidance is provided in the 2003 EPA Cross-Connection Control Manual which has been designed as a tool for health officials, waterworks personnel, plumbers, and any others involved directly or indirectly in water supply distribution systems, with more recent information in the AWWA Manual of Water Supply Practices M-24 (AWWA, 2009).

2.3.4.4 Maintenance Maintenance requirements for nonpotable components of the reclaimed water distribution system should be the same as for potable systems. From the outset, items such as isolation valves, which allow for repair to parts of the system without affecting a large area, should be designed into the system. Flushing the line after construction should be mandatory to prevent sediment from accumulating, hardening, and

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Chapter 2 | Planning and Management Considerations

becoming a serious future maintenance problem. New systems should confirm whether discharge of reclaimed water from the initial construction activity is allowed or considered an unauthorized discharge. The flush water may need to be returned to a sanitary sewer, or use of potable water may be considered for initial flushing. A reclaimed water supplier should reserve the right to withdraw service for any offending condition, subject to correction of the problem. Such rights are often established as part of a user agreement or reuse ordinance.

2.3.4.5 Quality Assurance: Monitoring Programs The purpose of monitoring is to demonstrate that the management system and treatment train are functioning according to design and operating expectations. Expectations should be specified in management systems, such as a Hazard Analysis and Critical Control Points (HACCP) or water safety plan (WSP). While the monitoring program will be based on the regulatory and permit requirements established for the system, the program not only must address those elements needed to verify the product water but also must support overall production efficiency and effectiveness. Having performance standards and metrics along with policies describing organizational goals and responsibilities for the execution of a water quality management program will reinforce a strong public perception of the overall water quality being produced. See Chapter 8 for additional discussion of public education and communication tools. Monitoring programs must establish goals for reclaimed water treatment performance and distribution system water quality, provide monitoring to

verify conformance with the goals, and establish appropriate actions if goals are not achieved. An example of water quality monitoring requirements for Texas is provided in Table 2-4. The Texas Commission on Environmental Quality (TCEQ) regulates wastewater reclamation and reuse in Texas. Under Chapter 210 of Texas Administrative Code, Volume 30, TCEQ prescribes the quality and use requirements as well as the responsibilities of producers and users. In addition to regulatory requirements, specific uses of reclaimed water, such as some industrial uses or even irrigation when it is for particular golf courses, may require additional testing and/or increased monitoring frequency. Monitoring requirements for reclaimed water are based on the intended use and not on the treatment process utilized to produce reclaimed water (TCEQ, 1997). Two reclaimed water use types are recognized by the TCEQ: Type I use is where contact with humans is likely, such as irrigation, recreational water impoundments, firefighting, and toilet flush water, and Type II use is where contact with humans is unlikely, such as in restricted or remote areas [US-TX-San Antonio]. Three to four parameters must be monitored in accordance with the intended use of the reclaimed water in Texas: E. coli or fecal coliform (cfu/100 mL), 5-day biochemical oxygen demand (BOD5) or 5-day carbonaceous biochemical oxygen demand (CBOD5) (mg/L), Turbidity (NTU) and Enterococci (cfu/100mL) (Table 2-4). Use type also affects monitoring frequency. Type I uses require a twiceweekly monitoring protocol while Type II uses require weekly monitoring.

Table 2-4 Quality monitoring requirements in Texas

Texas Category

Is human contact likely?

Type I

Yes

Type II

No

Examples Irrigation, recreational impoundments, firefighting, toilet flush water Restricted or remote reuse

Monitoring frequency

Enterococci (MPN/100mL)

Twice weekly

9/4

Once weekly

35

1

Fecal Coliforms or E. coli (MPN/100mL) 75/20

1

800/200

1

CBOD5 or BOD5 (mg/L)

Turbidity (NTU)

5

3

15 or 20

2

N/A

1

The first value represents a single sample maximum value and the next value refers to a 30-day average (BOD5 and Turbidity) or 30-day geometric mean (fecal coliform or E. coli).

2

In Type II uses, the CBOD5 maximum 30-day average value is 15 mg/L while the BOD5 value is 20 mg/l for the same period.

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The first element of a system monitoring program is choosing appropriate, quantifiable measurement parameters that relate to operational and regulatory decision-making. At a minimum, state-required regulatory parameters should be included for analysis. Parameters such as flow rates, distribution system water quality (measured by chlorine residual and bacteriological quality), and TDS are commonly included, but the final choice will depend on the individual system. Detailed monitoring lists may not be necessary once relationships between types of chemicals, treatment train performance, and surrogate measures have been established with definitive data generated from statistically robust experiments. For example, the city of San Diego’s water purification demonstration project monitors several water quality parameters, including contaminants regulated by the SDWA [US-CA-San Diego]. Online monitoring methods are preferred because they provide real-time data on system performance. Further, well-defined criteria must be set for each measurement parameter to support the facility’s water quality and productivity goals. These may be established by regulatory drivers or self-imposed as part of the overall quality or operational goals. As noted, in many instances the use of real-time remote measuring devices is required to maintain process and product quality control. Well-defined procedures for the care, calibration, calibration verification, and data collection for any remote or inline measurement devices should be established. For parameters that cannot be measured online, a routine sampling plan must be developed to select representative sampling sites that adequately cover all key elements (Critical Control Points [CCP]) in the process at a frequency sufficient to anticipate potential problems and respond before problems become critical. In addition to daily, weekly, or monthly analyses, periodic (quarterly or annually) analyses that are more comprehensive can further validate that the routine process performance indicators are adequate to detect potential problems. Locations where high failures are occurring may require more frequent sampling as part of the corrective action. Sampling methods should focus on obtaining data where the resulting accuracy is adequate for the intended purpose. Samples that are not immediately analyzed must be handled in a way that maintains

2012 Guidelines for Water Reuse

sample integrity. The validity of the sampling process can significantly impact the validity and usability of the data from those samples. Sampling procedures for required regulatory reporting should following wellaccepted practices, such as Standard Methods for the Examination of Water and Wastewater. Because regulatory and public perception of the monitoring program will rely heavily on the confidence in the quality and validity of the data collected, certifications or accreditations for laboratories doing analytical work supporting the water industries may be required. These can include state programs, such as Arizona Department of Health Services (ADHS), or national accreditation programs, such as The National Environmental Laboratory Accreditation Conference (NELAC) Institute (TNI, n.d.), which is used by states like Texas and Florida. The NELAC Institute (TNI) was formed in 2006 by combining the boards of the NELAC and the Institute for National Environmental Laboratory Accreditation. Accreditation may be required for both internal and commercial laboratories. These programs require laboratories that produce data to support water quality programs to have established basic quality requirements incorporated into their data collection processes. These requirements should include the analytical procedures, instrument calibration requirements, quality control practices and documentation, and reporting protocol sufficient to document the traceability and quality of the result. The city of Tucson, Ariz., has a well-established Reclaimed Water Site Inspection Program that accomplishes many of these goals [US-AZ-Tucson]. The program provides for periodic inspection of all sites having reclaimed water service, along with training and certification of reclaimed water site testers.

2.3.4.6 Response to Failures The final and probably most important element is a well-defined and rigorously-enforced procedure for responding to system failures within the defined criteria. Obviously, this will include procedures for returning to normal operation as quickly as reasonably possible, but it should also include root-cause analysis or other investigative techniques to determine if systematic problems exist. In addition to water quality monitoring, the system as a whole requires monitoring and maintenance. A number of best practices to monitor the system include:

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Contractor training requirements on the regulations governing reclaimed water installations



Requirements to submit all modifications to approved facilities to the responsible agencies



Detection and documentation of any breaks in the transmission main



Random inspections of user sites to detect any faulty equipment or unauthorized use



Installation of monitoring stations throughout the system to test pressure, chlorine residual, and other water quality parameters



Accurate recording of system flow to confirm total system use and spatial distribution of water supplied

2.3.5 Lessons Learned from Large, Medium, and Small Systems Regardless of the size of a reclaimed water system, there are lessons learned that can be applied to other systems, and several case study examples are highlighted below by system size. Large reclaimed water systems (large systems) are defined as systems with a capacity larger than 10 mgd (440 L/s). In general, large systems have matured from smaller, initial start-up or backbone facilities that were implemented to meet smaller demands in prior years. As illustrated by several current large systems in the United States, however, this may not always be the case. Medium reclaimed water systems (medium systems) are defined as systems with a capacity ranging from 1 to 10 mgd (44 to 440 L/s). And small systems are defined as facilities treating flows ranging 3 between 1,500 and 100,000 gpd (5.6 to 380 m /d), while small community systems may treat flows of up to 1 mgd (44 L/s) (Crites and Tchobanoglous, 1998). Large Systems. The scale of the delivery system for the case study examples varies from gravity plant discharge to delivery through 130 mi (210 km) of pipeline. Three of these systems started at near their

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current capacities by providing alternative water sources to mature markets with significant drivers to meet water supply needs under time constraints. The UOSA, for example, developed from regional concerns over water quality issues from small and individual systems draining to the Occoquan Reservoir [US-VAOccoquan]. What emerged from regional planning are key examples of planned IPR as a means of augmenting the raw water reservoir with high-quality source water, as depicted in Figure 2-9. Common themes throughout all of these large system case studies are the importance of public education and public information programs to educate staff, elected officials, the business community, and customers, which is discussed further in Chapter 8. These large projects include significant design challenges that have led to state-of-the-science technical applications to meet the project constraints. However, the successful application of technology for projects such as the Occoquan Reservoir has been documented in research by Rose et al. (2001). Application of the lessons learned from these large reclaimed water projects provides valuable information for all systems in technology application and proven results for public acceptance. Further, large reclaimed water system projects will typically involve more than one agency. In the case of OCWD and Orange County Sanitation District (OCSD), two boards worked together over many years to collectively solve problems and serve their individual system needs [US-CA-Orange County]. In the case of the Upper Occoquan project [US-VA-Occoquan], the UOSA was created by the state of Virginia and took over service obligations from numerous small providers. Supply to the Palo Verde Nuclear Generating Station (PVNGS) and USACE wetlands project in Arizona required public involvement and public hearings through state and two federal agencies [US-AZ-Phoenix]. San Antonio’s project [US-TX-San Antonio] was driven by endangered species lawsuits limiting future water withdrawals, which required multiple local, state, and federal agencies to work together.

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Figure 2-9 Upper Occoquan schematic

Each of these projects is an example of leaders and planners recognizing the importance of providing timely and accurate information to decision-makers and the public. These projects also provide valuable resource recovery and reuse to support the local water supply. In doing so, various permits required for the projects were issued because of community support. Medium Systems. Existing medium-sized facilities can benefit from the experience of larger systems as well as from the development of their existing systems. Medium-sized systems have typically worked through many of the same operational considerations and, in most cases, the community is aware of the benefits of reusing local resources. For medium systems in particular, identifying potential reclaimed water customers is one of the most important phases of planning the reuse system and ensuring that the system can be sustained. Unlike large systems with capacities of greater than 10 mgd (438 L/s), which generally have a set reclaimed water user baseline,

2012 Guidelines for Water Reuse

and smaller systems, which generally rely on a preidentified (and consistent) source of reclaimed water, medium systems are largely dependent on the needs of their customer bases. This need can greatly vary depending on the type of reclaimed water customer, the end use for the reclaimed water, and the time of year (i.e., decreased demands in wet weather months). Identifying potential customers will help evaluate the financial viability of a reuse system as well as provide an estimate of how much potable water can be saved by connecting customers to a new reclaimed water system. A more accurate estimate may be provided by contacting identified potential customers to determine their willingness to participate in converting a portion of their demands to reclaimed water. An excellent case study example of a medium system expanding its customer base is the city of Pompano Beach, Fla. [US-FL-Pompano Beach]. The city’s OASIS (Our Alternative Supply Irrigation System)

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program is taking a systematic approach to increase existing and future reuse capacity to achieve the region’s reuse requirements. Current plant capacity is 7.5 mgd (329 L/s), of which only 1.8 mgd (79 L/s) are produced because of a lack of demand. The city’s greatest reuse challenge has been convincing singlefamily residential customers to hook up to the system. While connection is mandatory for commercial and multi-family customers, the city did not mandate connection for single-family residences. Even though construction of the reuse mains required working in existing neighborhoods and placing a reuse meter box at each home, and even though each home pays a monthly available charge, single-family residential customers have been slow to connect to the system. Reasons range from connection cost to permitting issues. Residents also complained about the annual backflow preventer assembly certifications and the resulting payback time. In 2010, the city manager and the city commissioner approved a connection program to target single-family residential customers. The new program allows the city, working through a contractor, to perform the necessary plumbing on the customer’s property to connect to the reuse system and eliminates the annual certification requirement for the customer. Installation cost is covered by the city’s utilities department, which also retains ownership of the dual-check valve and meter. These costs are recovered through reclaimed 3 water use rate ($0.85/1,000 gallons [$0.22/m ] for the smallest meter size) that is slightly higher than existing reclaimed water use rates ($0.61/1,000 gallons 3 [$0.16/m ]). The program includes a public outreach campaign “I Can Water,” which launched in July 2011 with meetings, media outreach, mailers, cable TV, a Web page, and a hotline. To reward the existing 73 customers, the city will replace and take over their backflow devices and keep them at the current lower rate. Customer response to this campaign has been positive. Small Systems and Small Community Systems. Small systems and small community systems differ in both size and scope. Small systems typically serve a small development or project, while small community systems serve an entire community. Small systems can generally be classified according to the following categories: 

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Point-of-use systems for a specific user



A satellite facility within a medium or large system that is remote from the main WWTP or reclaimed water source



A decentralized system in an area without community collection and treatment



An internal industrial process reuse system



A start-up system in initial phases of development that is intended to progress to a medium or large system



A community reclaimed water system for a community generating less than 1 mgd (44 L/s) of plant flow

The scale of effort required in planning a small system is proportional to the system size. For example, the planning area for a small town may not be as large as a system for a population of 4 million, but small communities typically have fewer resources, so the effort can still be significant. Most of the systems will have similar regulatory hurdles, and all of the users in the categories above will need to address potential plant improvements to provide a water quality that will be acceptable to potential customers (sometimes in excess of the regulatory quality). There is often an overlap in the above categories. For example, in order to conserve water and money, a small community with an existing WWTP decides to start a reclaimed water system by providing reclaimed water to its golf course. In this case, the planning process may initially be truncated by having one customer that can use a large volume of water. During the summer in the arid south, an 18-hole golf course can use 2 ac-ft (2,500 MCM) of reclaimed water per night. For many small communities, this may exceed their capacity, and as a result during peak summer use the reclaimed water may only supplement the previous source water. If a small community is a little larger, success with the first customer may lead to another planning process to identify other customers and explore the possibility of extending the small reclaimed water system. An excellent case study example of this evolution is in Yelm, Wash. [US-WA-Yelm], where the community embraced reclaimed water as the best solution to safeguard public health, protect the Nisqually River, and provide an alternate water supply. While the city

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faced challenges, an intensive community outreach program helped the city successfully expanded its system into one of the first Class “A” Reclaimed Water Facilities in the state of Washington. Yelm constructed a wetlands park to have a highly visible and attractive focal point promoting reclaimed water use, and a local reclaimed water ordinance was adopted, establishing the conditions of reclaimed water use. The ordinance includes a “mandatory use” clause allowing Yelm to require construction of reclaimed water distribution facilities as a condition of development approval. Yelm continues to plan expansion of storage, distribution, and reuse facilities, and in 2002 the city received the Washington State Department of Ecology’s Environmental Excellence Award for successfully implementing Class “A” reclaimed water into its community. Additional information on low-cost treatment technologies for small-scale water reuse projects is provided in a recent WRRF report on Low-Cost Treatment Technologies for Small-Scale Water Reclamation Plants, which identifies and evaluates established and innovative technologies that provide treatment of flows of less than 1 mgd (44 L/s) (WRRF, 2012). A range of conventional treatment processes, innovative treatment processes, and package systems was evaluated with the primary value of this work including an extensive cost database in which cost and operation data from existing small-scale water reclamation facilities have been gathered and synthesized.

2.4 Water Supply Conservation and Alternative Water Resources Water scarcity is one of the key drivers for developing reclaimed water supplies and systems. As part of the overall management of water resources, it is critical to evaluate alternative management strategies for making the most of the existing supplies. Water conservation is an important management consideration for managing the water demand side. On the supply side, the use of alternative water resources, such as reuse of graywater, rainwater harvesting (where applicable), produced water, and other reuse practices, should also be considered as part of an overall plan.

communities outside of the traditional water-short regions of the United States. Catalysts for implementing water conservation programs include growing competition for limited supplies, increasing costs and difficulties with developing new supplies, increasing demands that stress existing infrastructure, and growing public support for resource protection and environmental stewardship. As a result of the growing interest in water conservation, one of EPA's most successful partnership programs is WaterSense®, which supports water efficiency by developing specifications for water-efficient products and services (EPA, 2012). The program also provides resources for utilities to help promote their water conservation programs. In addition to using conservation as a means to utilities to help meet growing water demands, many utilities are also beginning to understand the value of water conservation as a way of saving on costs for both the utility and its customers. Throughout the United States, utilities have experienced quantifiable benefits associated with long-term water conservation programs, including: 

Reduction in operation and maintenance costs resulting from lower use of energy for pumping and less chemical use in treatment and disposal



Less expensive than developing new sources



Reduced purchases from wholesalers



Reduce, defer, or eliminate need for capacity expansions and capital facilities projects

Selecting the appropriate conservation program components includes understanding water use habits of customers, service area demographics, and the water efficiency goals of the utility; some of the most effective practices that encourage conservation include: 

Customer education



Metering



Rate structures with a volumetric component with rate increases with increased use (tiered rate structure)



Irrigation efficiency measures

2.4.1 Water Conservation Integrating water conservation goals and programs into utility water planning is emerging as a priority for

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Time-of-day and day-of-week water limitations



Seasonal limitations and/or rate structures



High-efficiency device distribution and rebates

Since 1991, for example, the Los Angeles Department of Water and Power has installed more than one million ultra-low-flush toilets and hundreds of thousands of low-flow showerheads and has provided rebates for high-efficiency washing machines and smart irrigation devices. The city used less water in 2010 than it did in 1990, despite adding more than 700,000 new residents to its service area (Rodrigo et al., 2012). While it is clear that potable water resources should be conserved for the reasons above, reclaimed water in some regions of the country is not considered a resource; rather, it is sometimes viewed as a waste that must be disposed of. With this mindset, customers are sometimes encouraged to use as much reclaimed water as they want, whenever they want. In areas where there are fresh water supply shortfalls or where reclaimed water has become valued as a commodity, however, conservation has also become an important element of reclaimed water management. As a result, reclaimed water is recognized by many states as a resource too valuable to be wasted. The 1995 Substitute Senate Bill 5605 Reclaimed Water Act, passed in the state of Washington, stated that reclaimed water is no longer considered wastewater (Van Riper et al., 1998). The California legislature has declared, “Recycled water is a valuable resource and significant component of California’s water supply” (California State Water Resources Control Board, 2009). These recent declarations are part of broad statewide objectives to achieve sustainable water resource management. Chapter 8 describes how water conservation and water reuse public outreach can be synergistic. Efficient and effective use can be critical to ensure that the reclaimed water supply is available when there is a demand for it. In addition, storage of reclaimed water can focus on periods of low demand for later use during high-demand periods, thereby stretching available supplies of reclaimed water and maximizing its use. While this practice is sometimes a challenge, it is gaining interest because of recent advances in management practices, such as ASR, which is discussed in Section 2.3.

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Several conservation methods that are used in potable water supply systems are applicable to reclaimed water systems, including volume-based rate structures, limiting irrigation to specific days and hours, incorporation of soil moisture sensors or other controllers that apply reclaimed water when conditions dictate irrigation, and metering. Examples of reclaimed water conservation are prevalent in Florida. Many utilities’ reclaimed water availability is limited by seasonal demands that can exceed supply, making conservation and management strategies a necessity. To promote conservation, several utilities have implemented conservation rate structures to encourage efficient use of reclaimed water. In addition, utilities that provide reclaimed water for landscape irrigation, including irrigation for residential lots, medians, parks, and other green space, are promoting efficient use of reclaimed water by limiting the days and hours that users can irrigate. The Loxahatchee River District in Palm Beach County, Fla., has designated irrigation days for residential landscape irrigation reuse customers and can shut off portions of its system on designated non-irrigation days. Port Orange, Fla., retrofitted its entire reuse system with meters so that customers could be charged according to a tiered volumetric rate rather than a flat rate that encouraged excessive use. And the Southwest Florida Water Management District has recognized the importance of conserving reclaimed water to ensure more customers can be served by providing grant funding for reuse programs where efficient use is a criterion for receiving funds.

2.4.2 Alternative Water Resources While these guidelines are intended to highlight the reuse of reclaimed water derived from treated municipal effluent, there are a number of other alternative water sources that are often considered and managed in a manner similar to reclaimed water. Some of the most important alternative water resources include individual and on-site graywater and stormwater.

2.4.2.1 Individual On-site Reuse Systems and Graywater Reuse Graywater is untreated wastewater, excluding toilet and—in most cases—dishwasher and kitchen sink wastewaters. Wastewater from the toilet and bidet is "blackwater," and while the exclusion of toilet waste is a key design factor in on-site and graywater systems, this does not necessarily prevent fecal matter and

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other human waste from entering the graywater system—albeit in small quantities. Examples of routes for such contamination include shower water and bathwater and washing machine discharge after cleaning of soiled underwear and/or diapers (Sheikh, 2010). In fact, California's latest graywater standards define graywater as untreated wastewater that has not been contaminated by any toilet discharge; has not been affected by infectious, contaminated, or unhealthy bodily wastes; and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes. Graywater does include wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include wastewater from kitchen sinks or dishwashers (California Building Standards Commission, 2009). Thus, for a graywater system, it is assumed that a building or homeowner would take extraordinary care in source control of contaminants and ensure pathogen-free graywater, an assumption that could be questionable in a certain percentage of cases. For these reasons, use of graywater has been a controversial practice. While viewed by some as the panacea for water shortages, groundwater depletion, surface water contamination, and climate change, use of graywater can also be seen as a threat to the health and safety of the users and their neighbors. While the reality of graywater lies somewhere between these two perceptions, the installation of a graywater system may save a significant amount of potable water (and its costs) for the homeowner or business, even though the payback period for the more complex systems may exceed the useful life of the system. Graywater use does not always reduce total water use, as shown in a study in Southern Nevada (Rimer, 2009). Because all wastewater in the region is collected, treated, and returned to Lake Mead, all water is already reused. Using untreated or partially treated graywater had higher public health risk than continued use of reclaimed water, and graywater users felt less constrained in using potable water, actually increasing total metered water use. There are no documented cases in the United States of any disease that has been caused by exposure to graywater—although systematic research on this public health issue is virtually nonexistent. And, while the absence of documentation does not prove that there has never been such a case, graywater is, in fact, wastewater with microbial concentrations far in excess of levels

2012 Guidelines for Water Reuse

established in drinking, bathing, and irrigation water standards for reclaimed water (Sheikh, 2010). Graywater Policy and Permitting. Key to the viability of small or on-site graywater systems is an effective policy, permitting, and regulatory process to provide adequate treatment of graywater for the intended end use. In many states the regulatory system is still designed for large-scale systems; the permitting process for small systems is complex because small systems cross into the purview of various regulatory agencies, which can cause hurdles in the approval process. There are a number of states and local agencies that provide specific regulations or guidance for graywater use, including Arizona, California, Connecticut, Colorado, Georgia, Montana, Nevada, New Mexico, New York, Massachusetts, Oregon, Texas, Utah, Washington, and Wyoming. In addition to the states that have specific policies on graywater use, there are other institutional policies, such as the UPC and the IPC, that are applicable to the implementation of graywater systems. A comprehensive compilation of graywater laws, suggested improvements to graywater regulations, legality and graywater policy, sample permits, public health considerations, studies, and other considerations has been assembled by Oasis Design, a firm with vested interest in promoting use of graywater. Links to numerous resources targeted at regulators, inspectors, elected officials, building departments, health departments, builders, and homeowners have been posted by Oasis Design (Oasis Design, 2012). Graywater Quality Criteria. For any size and type of system, proper consideration for public health begins with risk management, which puts in place mechanisms to minimize or eliminate the risk of contaminated water entering the water supply. Thus, from a policy perspective, the first step in risk management is establishing transparent criteria for water quality; the NSF Standard 350 establishes water quality criteria for on-site systems. In 2011, NSF/ANSI Standard 350 Onsite Residential and Commercial Water Reuse Treatment Systems and NSF/ANSI Standard 350-1 Onsite Residential and Commercial Graywater Treatment Systems for Subsurface Discharge were adopted (NSF, 2011a and 2011b). The standards provide detailed methods of evaluation; product specifications; and criteria related to materials, design and construction, product

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literature, wastewater treatment performance, and effluent quality for on-site treatment systems. Graywater treatment to NSF 350 levels also requires certified operators, reliability, and public water supply protection. The NSF/ANSI Standard 350 is for graywater treatment systems with flows up to 1,500 3 gpd (5.7 m /d) or larger. The standards apply to graywater treatment systems having a rated treatment 3 capacity of up to 1,500 gpd (5.7 m /d), residential wastewater treatment systems with treatment 3 capacities up to 1,500 gpd (5.7 m /d), and commercial treatment systems with capacities exceeding 1,500 3 gpd (5.7 m /d) for commercial wastewater and commercial laundry facilities. End uses appropriate for reclaimed water from these systems include indoor restricted urban water use, such as toilet flushing, and outdoor unrestricted urban use, such as surface irrigation. The Standard 350 effluent criteria (Table 2-5) are applied consistently to all treatment systems regardless of size, application, or influent quality. Effluent criteria in Table 2-5 must be met for a system to be classified as either a residential treatment system for restricted indoor and unrestricted outdoor use (Class R) or a multi-family and commercial facility water treatment system for restricted indoor and unrestricted outdoor use (Class C). The NSF/ANSI Standard 350-1 is for graywater treatment systems with flows up to 1,500 gpd 3 3 (5.7 m /d). For systems above 1,500 gpd (5.7 m /d), a multiple-component system should be performance tested for at least 6 months at the proposed site of use

following the field evaluation protocol in Annex A of NSF-350. Annex A prescribes testing sequence, frequency of sampling and testing, and test protocol acceptance and review procedures. End uses appropriate for these systems include only subsurface discharges to the environment. The effluent requirements of graywater systems seeking certification through the ANSI/NSF Standard 350-1 for subsurface discharge are provided in Table 2-6. Table 2-6 Summary of ANSI/NSF Standard 350-1 for subsurface discharges Parameter

Test Average

CBOD5 (mg/L)

25 mg/L

TSS (mg/L)

30 mg/L

pH (SU)

6.0 – 9.0 1

Color

MR

Odor

Non-offensive

Oily film and foam

Non-detectable

Energy consumption 1

MR

MR: Measured reported only.

It is important to note that while the NSF/ANSI Standards provide detailed information for graywater use, individual state statutes and regulations and local building codes, which generally take precedence, may not allow graywater use in a given locale. Implementation of Residential and Commercial Onsite and Graywater Treatment Systems. Treatment technologies that can be used for meeting the stringent standards of ANSI/NSF 350 and 350-1

Table 2-5 Summary of NSF Standard 350 Effluent Criteria for individual classifications Class R Class C Single Sample Single Sample Parameter Test Average Maximum Test Average Maximum CBOD5 (mg/L) 10 25 10 25 TSS (mg/L) 10 30 10 30 Turbidity (NTU) 5 10 2 5 2 E. coli 14 240 2.2 200 (MPN/100 mL) 1 pH (SU) 6.0 – 9.0 NA 6.0 – 9.0 NA Storage vessel disinfection ≥ 0.5 – ≤ 2.5 NA ≥ 0.5 – ≤ 2.5 NA 3 (mg/L) 4 Color MR NA MR NA Odor Nonoffensive NA Nonoffensive NA Oily film and foam Nondetectable Nondetectable Nondetectable Nondetectable Energy consumption MR NA MR NA 1 2 3 4

NA: not applicable Calculated as geometric mean As total chlorine; other disinfectants can be used MR: Measured reported only

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include suspended media treatment, fixed media treatment systems, and constructed wetland systems. All of these technologies must be followed by advanced filtration and disinfection. On-site applications of membrane bioreactor (MBR) technology have also been utilized effectively in commercial and residential properties for outdoor irrigation and indoor nonpotable uses. Design standards for treatment systems are enforced through local health and environmental agencies, and permits to operate on-site treatment systems often include requirements for increased levels of monitoring. Because increased monitoring can be burdensome for small systems, operational monitoring can be used to determine if the system is performing as expected. By using instrumentation and remote monitoring technologies, small schemes can produce real-time data to ensure the system is functioning according to water quality objectives. This operational monitoring strategy is a risk management methodology borrowed from the food and beverage industry; the HACCP is a preventive approach that identifies points of risk throughout the treatment process and assigns corrective actions should data reveal heightened risk (Natural Resource Management Ministerial Council, Environment Protection and Heritage Council and Australian Health Ministers’ Conference, 2006). Water quality parameters are set at different CCPs and monitored in real-time online; if data reveal water quality is outside the set parameters, a corrective action will be triggered automatically in real time. With an operational monitoring model in place, ongoing sampling serves only as confirmation of the operational data, and frequency of regulatory sampling could be reduced. In the case where indoor uses are allowed, turbidity meters are often employed as a measure of system performance. While the quantitative impact of increased graywater use is expected to be modest, even under the most aggressive growth assumptions, much of the growth in graywater use is expected to take place in areas where municipal water reuse will likely not be practiced—unsewered urban areas and rural and remote areas, as exemplified in several case studies [Australia-Sydney]. Further, there are growing possibilities for increased on-site treatment systems in urban buildings that are LEED certified.

2012 Guidelines for Water Reuse

2.4.2.2 LEED-Driven On-site Treatment A recent development in on-site treatment systems in urban development has been driven largely by the private sector’s desire to create more highly sustainable developments through the LEED program. This program area remains small compared to the municipal reuse market. However, it has a growing role for improving water efficiency in new buildings and developments and also for major modifications to existing facilities. A primary driver that compels land developers to consider the implementation of on-site treatment systems is the sustainability accreditation that is promoted and earned through the LEED program. The LEED program was developed by the U.S. Green Building Council (USGBC) in 2000 and represents an internationally-recognized green building certification system. At the time of preparation of this document, the current version of the Rating System Selection Guidance was LEED 2009, originally released in January 2010 and updated in September 2011. The guidance is currently under revision with the new LEED v4 focusing on increasing technical stringency from past versions and developing new requirements for project types such as data centers, warehouses and distribution centers, hotels/motels, existing schools, existing retail, and mid-rise residential buildings. More information is available on the USGBC website (USGBC, n.d.). LEED provides building owners/operators with a framework for the selection and implementation of practical, measurable, and sustainable green building design, construction, and operations and maintenance solutions. LEED promotes sustainable building and site development practices through a tiered certification rating system that recognizes projects that implement green strategies for better overall environmental and health performance. The LEED system evaluates new developments, as well as significant modifications to existing buildings, based on a certification point system where applicants may earn up to a maximum of 110 points. LEED promotes a whole-building approach to energy and water sustainability by observance of these seven key areas of the LEED evaluation criteria: 1) sustainable sites, 2) water efficiency, 3) energy and atmosphere, 4) materials and resources, 5) indoor air quality, 6) innovation and design process, and 7) regionalspecific priority credits. Developments may qualify for LEED certification designation and points, according to the following qualified certification categories:

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LEED Certified – 40 to 49 points



LEED Silver – 50 to 59 points



LEED Gold – 60 to 79 points



LEED Platinum - 80+ points

On-site treatment systems can comprise a substantial fraction of the certification points with these systems qualifying for up to a maximum number of 11 points through the water efficiency and innovation and design processes in combination with water conservation practices. On-site water treatment systems may qualify for up to 10 points in the water efficiency category through water efficient design, construction, and longterm operation and maintenance features that promote water conservation and efficiency as follows: 

Water Efficient Landscaping, 2 to 4 points



Innovative Wastewater Technologies, 2 points



Water Use Reduction, 2 to 4 points

The on-site treatment system must provide water use reductions in conjunction with an associated water conservation program to secure a maximum number of LEED water efficiency points. An on-site treatment system may also help qualify for an Innovation in Design Process maximum credit of one point. A major sub-category under the Water Efficiency section of the LEED criteria is water use reduction. The water use reduction subcategory determines how much water use can be reduced in and around a LEED-certified development. One item that can receive a score under water reuse is a rainwater (rooftop) harvesting system. The harvested rainwater resource may then be combined with an on-site graywater treatment system, a high-quality wastewater treatment system, or with the use of a municipal reclaimed water system source. The combination of the rainwater harvesting system with either a graywater treatment system, an on-site wastewater treatment system, or a municipal reuse system can together account for a total of up to seven LEED points. While this practice is contrary to the conventional practice of avoiding dilution of biologically degradable material in the sewage that is used by municipal wastewater treatment processes, the on-site treatment system allows multiple objectives of reducing effluent discharges and reducing stormwater

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runoff while providing water that can be used for nonpotable purposes. The Fay School, located in Southborough, Mass., achieved LEED Gold Certification from the USGBC. The Fay School students now monitor building energy and building water consumption from a digital readout in each new dormitory building. The entire project was developed from the Fay School’s interest in sustainable design principles and educates the students on the importance of water efficiency [US-MA-Southborough]. Battery Park City in lower Manhattan, New York City, is a collection of eight high-rise structures with 2 10 million ft of floor area that serves 10,000 residents plus 35,000 daily transient workers. Water for toilet flushing, cooling, laundry, and irrigation comes from six on-site treatment systems. On-site systems use MBR technology for biological treatment and UV and ozone for disinfection. Potable water is supplied by New York City and the on-site treatment systems overflow to a combined wastewater/stormwater outfall. All buildings in Battery Park City are LEED certified Gold or Platinum (WERF, n.d.). In an industrial setting, the Frito-Lay manufacturing facility in Casa Grande, Ariz., received a LEED Gold EB (Existing Building) certification with modification to the manufacturing process to incorporate an on-site process water treatment system and addition of 5 MW of on-site photovoltaic power generation [US-AZ-Frito Lay]. Reclaimed water, along with other major alternative water sources, such as harvested rainwater and collected stormwater runoff, offer the opportunity to maximize landscape irrigation and reduce potable water use at many industrial and commercial institutions and at multi-family residential developments. In the south and southwest United States, air conditioning condensate collection and reuse may represent another significant alternate water resource. On-site treatment systems can be designed to treat municipal wastewater, graywater, harvested rainwater, and stormwater. Regardless of water source selected for use, care must be taken to differentiate pipes on the private side of the municipal utility boxes, appropriately color code on-site pipes, and adopt a cross-connection control program for the different water sources.

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2.4.2.3 Stormwater Harvesting and Use Comprehensive and sustainable integrated water management programs should also consider multiple goals, including those that are related to stormwater, such as cost-effectively controlling flooding and erosion; improving water quality; conserving, sustaining, and recharging water supply; and preserving and restoring the health of wetlands and aquatic ecosystems. Because rainfall is generally the most significant factor in managing stormwater, capture and harvesting of rainfall and associated runoff present opportunities for stormwater use benefits. These include direct use of runoff for urban and agricultural irrigation, alternative water supply, aquifer recharge and saltwater intrusion barriers, wetlands enhancement, low (minimum) flow augmentation, feed lot cleaning, heating ventilation and air conditioning (HVAC) and power plant cooling, firefighting, and toilet flushing. However, stormwater harvesting requires an effective means of stormwater capture and retention that also supports the concurrent need for flood control. A good example of this practice is Cape Coral, Fla., which has maintained a very effective stormwater harvesting program since the 1980s primarily because of its extensive network of canals throughout the city. Within Cape Coral’s integrated water management system, stormwater makes up as much as 75 percent of the irrigation water demand in the city, which allows for 100 percent reuse of the city’s wastewater flows. Another case study that highlights these benefits is from the Water Purification Eco-Center (WPEC) at the Rodale Institute in Kutztown, Pa. [US-PA-Kutztown]; the WPEC project captures rainwater for public septic use and treats the septic water to be returned to the surrounding environment. While the benefits of stormwater harvesting are clear, there are currently no federal regulations governing rainwater harvesting for nonpotable use, and the policies and regulations enacted at the state and local levels vary widely from one location to another. Regulations are particularly fragmented with regard to water conservation, as the permissible uses for harvested water tend to vary depending on the climate and reliability of the water supply. There are local plumbing codes, and some states, including Georgia, have published Rainwater Harvesting Guidelines, but not all states have formally defined rainwater harvesting as a practice distinct from water recycling (Georgia Department of Community Affairs, 2009). In

2012 Guidelines for Water Reuse

recent years, cities and counties looking to promote water conservation have begun issuing policies that better define harvested water and its acceptable uses. The city of Portland, Ore., for example, provides explicit guidance on the accepted uses of harvested water both indoors and outdoors. In January 2010, Los Angeles County issued a policy providing a clear, regulatory definition of “rainfall/nonpotable cistern water” and drawing a specific distinction between harvested water and graywater or recycled water. In 2010, IAPMO published the Green Plumbing and Mechanical Code Supplement (GPMCS). The supplement is a separate document from the Uniform Plumbing and Mechanical Codes and establishes requirements for green building and water efficiency applicable to plumbing and mechanical systems. The purpose of the GPMCS is to “provide a set of technically sound provisions that encourage sustainable practices and works towards enhancing the design and construction of plumbing and mechanical systems that result in a positive long-term environmental impact” (IAPMO, 2010). In addressing “Non-potable Rainwater Catchment Systems,” the GPMCS specifically identifies provisions for collection surfaces, storage structures, drainage, pipe labeling, use of potable water as a back-up supply (provided by air-gap only), and a wide array of other design and construction criteria. It also refers to and incorporates information from the ARCSA/ASPE Rainwater Catchment Design and Installation Standard (2008), a joint effort by the American Rainwater Catchment Systems Association (ARCSA) and the American Association of Plumbing Engineers (ASPE) (ARCSA/ASPE, 2008).

2.5 Environmental Considerations

Increasing water withdrawals, coupled with effluent discharges from WWTPs and agricultural runoff, can dramatically alter the hydrological cycles and nutrient cycling capacity of aquatic ecosystems. Water reuse can have both positive and adverse impacts on surrounding and downstream ecosystems. Elimination or reduction of a surface water discharge by reclamation and reuse generally reduces adverse water quality impacts to the receiving water. However, development of water reuse systems may have unintended environmental impacts related to land use, stream flow, and groundwater quality.

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Chapter 2 | Planning and Management Considerations

An environmental assessment may be required to meet state regulations or local ordinances and is required whenever federal funds are used. Formal guidelines for the development of an environmental impact statement (EIS) have been established by EPA. Such studies are generally associated with projects receiving federal funding or new NPDES permits and are not specifically associated with reuse programs. Where an investigation of environmental impacts is required, it may be subject to state policies. The following conditions could induce an EIS in a federally-funded project: 

The project may significantly alter land use.



The project is in conflict with land use plans or policies.



Wetlands will be adversely impacted.



Endangered species or their habitat will be affected.



The project is expected to displace populations or alter existing residential areas.



The project may adversely affect a floodplain or important farmlands.



The project may adversely affect parklands, preserves, or other public lands designated to be of scenic, recreational, archaeological, or historical value.



The project may have a significant adverse impact upon ambient air quality, noise levels, or surface or groundwater quality or quantity.



The project may have adverse impacts on water supply, fish, shellfish, wildlife, and their actual habitats.

changes include land use alterations associated with industrial, residential, or other development made possible by the added supply of water from reuse. Other examples of changes in land use as a result of available reclaimed water include the potential for urban or industrial development in areas where natural water availability limits the potential for growth. For example, if the supply of potable water can be increased through recharge using reclaimed water, then restrictions to development might be reduced or eliminated. Even nonpotable supplies, made available for uses such as residential irrigation, can affect the character and desirability of developed land in an area. Similar effects can also happen on a larger scale, as municipalities in areas where development options are constrained by water supply might find that nonpotable reuse enables the development of parks or other amenities that were previously considered to be too costly or difficult to implement. Commercial users, such as golf courses, garden parks, or plant nurseries, have similar potential for development given the presence of reclaimed water supplies.

2.5.2 Water Quantity Impacts Instream flows and levels in lakes and reservoirs can either increase or decrease as a consequence of reuse projects. In each situation where reuse is considered, there is the potential to shift water balances and effectively alter the prevailing hydrologic regime in an area, with the potential to damage or improve impacted ecosystems. Where wastewater discharges have occurred over an extended period of time, the flora and fauna can adapt and even become dependent on that water. A new or altered ecosystem can arise, and a reuse program implemented without consideration of this fact could have an adverse impact on such a community. Examples of how flows can increase as a result of a reuse project include: 

In streams where dry weather base flows are groundwater dependent, land application of reclaimed water for irrigation or other purposes can cause an increase in base flows, if the prevailing groundwater elevation is raised.



Increases in stream flows during wet periods can result from pervasive use of recharge on the land surface during dry periods. In such a case, antecedent conditions are wetter, and less water moves into the ground, thereby increasing

These types of activities associated with federal EIS requirements are described below. Many of the same requirements are incorporated into environmental assessments required under state laws.

2.5.1 Land Use Impacts Water reuse can induce significant land use changes, either directly or indirectly. Direct changes include shifts in vegetation or ecosystem characteristics induced by alterations in water balance in an area, such as wetland restoration or creation. Indirect

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Chapter 2 | Planning and Management Considerations

runoff during a rainstorm. The instream system bears the consequences of this change. 

Instream flow reduction is also possible and can impact actual or perceived water rights. For example, the Trinity River in Texas, near the Dallas-Fort Worth Metroplex, maintains a continuous flow of several hundred cubic feet per second during dry periods due to return flows (discharges) from multiple WWTPs. If extensive reuse programs were to be implemented at the upstream facilities, dry weather flows in the Trinity River would be reduced, and plans for urban development downstream could potentially be impacted due to water restriction. Houston-area interest near the downstream end of the Trinity River stalled TCEQ issuance of Metroplex discharge and bed and banks transfer permits for several years until agreements were reached with individual large discharges in the Metroplex to maintain minimum flow to Lake Livingston, a primary source of drinking water for Houston.

In southern Arizona, the San Pedro River is distinct as the last free-flowing undammed river in Arizona, which supports a unique desert riparian ecosystem. Population growth around Sierra Vista has caused a significant drop in the groundwater table, which in turn reduces the stream flow in the river. Ecological considerations, including the protection of endangered species, prompted the decision to recharge the underlying aquifer with reclaimed water. Environmental Operations Park (EOP) in Sierra Vista includes a reclamation facility that polishes reclaimed water in constructed wetlands. The reclaimed water is then used to recharge the local aquifer in order to mitigate the adverse impacts of continued groundwater pumping in the San Pedro River system. The Sierra Vista EOP was established as a multi-use center, combining recharge basins, constructed wetlands, native grasslands, and a wildlife viewing facility [USAZ-Sierra Vista]. An example from Sydney, Australia provides a rather unusual case where water reclamation was designed explicitly for environmental flows. Drinking water supplies in Sydney’s main storage reservoir (Warragamba Dam) were rapidly declining between 2000 and 2006 due to severe drought. By law, Warragamba Dam was also required to continue to

2012 Guidelines for Water Reuse

provide satisfactory environmental flows (4.8 billion gallons [18 MCM] released annually) in the downstream Hawkesbury Nepean River system. A massive water reclamation project was implemented [Australia-Replacement Flows] to replace the Warragamba Dam’s discharge with an alternative high-quality water source that met the required downstream environmental flows. The SAWS in Texas defined the historic spring flow at the San Antonio River headwaters during development of its reclaimed water system. In cooperation with downstream users and the San Antonio River Authority, SAWS agreed to maintain release of 55,000 ac-ft/yr (68 MCM/yr) from its water reclamation facilities. This policy protects and enhances downstream water quality and provides 35,000 ac-ft/yr (43 MCM/yr) of reclaimed water for local use [US-TXSan Antonio].The implication of these examples is that a careful analysis of the entire hydrologic system is an appropriate consideration in a reuse project, particularly where reuse flows are large, relative to the hydrologic system that will be directly impacted. Likewise, analysis of the effects from the chemical, physical, and biological constituents in discharges of reclaimed water must be considered where the end use is environmental flows; this is the same or similar to what is required for discharges of wastewater effluent.

2.5.3 Water Quality Impacts There are potential water quality impacts from introducing reclaimed water back into the environment. The ecological risks associated with environmental reuse applications can be assessed relative to existing wastewater discharge practices (NRC, 2012); additional discussion on this topic is provided in Chapter 3. The report concludes that the ecological risks in reuse projects for ecological enhancement are not expected to exceed those encountered with the normal surface water discharge of treated municipal wastewater. Indeed, risks from reuse could be lower if additional levels of treatment are applied. The report cautions that current limited knowledge about the ecological effects of trace chemical constituents requires research to link population-level effects in natural aquatic systems to initial concerning laboratory observations. In reuse applications targeted for ecological enhancement of sensitive aquatic systems, careful assessment of risks from these constituents is warranted because aquatic organisms can be more

2-39

Chapter 2 | Planning and Management Considerations

sensitive to certain constituents than humans (NRC, 2012).

.

In addition to potential impacts on surface water quality, groundwater quality can be significantly impacted by recharge with reclaimed water. Recharging groundwater with reclaimed water may change the water quality in the receiving aquifer. Conditions must be evaluated on a case-by-case basis, depending on potential constituents present in reclaimed water and the underlying site hydrogeology; additional discussion is provided in Section 2.3.3.

California State Water Resources Control Board (SWRCB). 2009. Recycled Water Policy. Retrieved July 2012, from .

2.6 References

ARCSA/ASPE, 2008, Rainwater Catchment Design and Installation Standard. Retrieved August 23, 2012 from . American Water Works Association (AWWA). 2009. Manual of Water Supply Practices M-24: Planning for the Distribution of Reclaimed Water. 3rd edition. American Water Works Association. Denver, CO.

CDM. 2005. Urban Water Management Plan. Report prepared for City of Los Angeles. CDM. Los Angeles, CA. CH:CDM. 2006a. Integrated Resources Plan, Facilities Plan, Volume 2. Report prepared for City of Los Angeles. CDM. Los Angeles, CA. CH:CDM. 2006b. Integrated Resources Plan, Facilities Plan, Volume 3. Report prepared for City of Los Angeles. CDM. Los Angeles, CA. CH:CDM. 2006c. Integrated Resources Plan, Facilities Plan, Volume 4. Report prepared for City of Los Angeles. CDM. Los Angeles, CA.

American National Standard Institute (ANSI), 2007. Standard Z535.1- 2006, For Safety Colors, Rosslyn, VA.

Common Ground Alliance (CGA). 2011. Best Practices Version 8.0, Washington, DC. Retrieved August 2012 from .

AWWA California-Nevada Section (1997) Guidelines for the On-Site Retrofit of Facilities Using Disinfected Tertiary Recycled Water. Orange County, CA.

Crites, R. W., and G. Tchobanoglous. 1998. Small and Decentralized Wastewater Management Systems. McGrawHill. New York.

Ballaro, C. 2012. “Need for Water Conservation Stressed, Water Management Plan Laid Out for Cape Council.” Cape Coral (FL) Daily Breeze, April 16, 2012. Retrieved April 2012 from .

Dublin San Ramon Services District (DSRSD). 2005. Recycled Water Use Guidelines and Requirements. Retrieved July 2012 from .

Bell, K.Y; L.P. Wiseman; and L. Turner. 2009. “Designing Pretreatment to Control Arsenic Leaching in ASR Facilities.” Journal of the American Water Works Association. 101(6): 74-84. California Building Standards Commission. 2009. Express Terms for Proposed Emergency Building Standards of the Department of Housing and Community Development Regarding the 2007 California Plumbing Code (CPC), California Code of Regulations, Title 24, Part 5, Chapter 16A, Part I (Graywater Standards). Retrieved January 2010, from . California Department of Public Health (CDPH). 2011. Draft Regulations for Groundwater Replenishment with Recycled Water. November 21, 2011. Retrieved August 2012, from

2-40

Entrix. 2010. “ASR Using Sodium Bisulfide Treatment for Deoxidation to Prevent Arsenic Mobilization.” Proceedings of the Aquifer Recharge Conference. Orlando, FL. Florida Department of Environmental Protection (FDEP). n.d. Retrieved July 2012 from . Florida Department of Environmental Protection (FDEP). 2009. Florida Section Resources. Retrieved August 2012, from . Fox, P. 2002. “Soil Aquifer Treatment: An Assessment of Sustainability.” In Management of Aquifer Recharge for Sustainability. A. A. Balkema Publishers. Australia.

2012 Guidelines for Water Reuse

Chapter 2 | Planning and Management Considerations

Georgia Department of Community Affairs. 2009. Georgia Rainwater Harvesting Guidelines. Retrieved August 2012, from .

National Research Council. 2008. Prospects for Managed Underground Storage of Recoverable Water. The National Academies Press. Washington, D.C.

Gordon, H. B., L. D. Rotstayn, J. L. McGregor, M. R. Dix, E. A. Kowalczyk, S. P. O'Farrell, L. J. Waterman, A. C. Hirst, S. G. Wilson, M. A. Collier, I. G. Watterson, and T. I. Elliott. 2002. “The CSIRO Mk3 Climate System Model.” In CSIRO Atmospheric Research Technical Paper, no. 60. Commonwealth Scientific and Industrial Research Organisation. Australia.

NSF/ANSI 350-2011 (NSF). 2011a. Onsite Residential and Commercial Water Reuse Treatment Systems. National Sanitation Foundation, Ann Arbor, Michigan, July 2011.

Henry, R. 2011. “Lake Lanier Water Dispute: Court Won’t Rehear Ruling.” Huffington Post. Retrieved August 2012, from . International Association of Plumbing and Mechanical Officials. 2010. Green Plumbing and Mechanical Code Supplement. IAPMO. Ontario, Canada. Kazner, C.; T. Wintgens; and P. Dillon. 2012. Water Reclamation Technologies for Safe Managed Aquifer Recharge. IWA Publishing. London, UK. López Calva, E., A. Magallanes, and D. Cannon. 2001. “Systems Modeling for Integrated Planning in the City of Los Angeles: Using Simulation as a Tool for Decision Making.” th WEFTEC 2001. Water Environment Federation 74 Annual Conference and Exhibition. Atlanta, GA. Marina Coast Water District, CA. 2002. Title 4. Recycled Water Chapter 4.28 Recycled Water, Supplement 3-02 to Ordinance 29 § 4, 5, and 6, 1995; and Ordinance 27 § 5, 1994, Retrieved April 2012 from . Mirecki, J. E. 2010. “Dynamics of Sulfate Reduction in the Floridian Aquifer System with Implications for Arsenic Sequestration at Reclaimed and Treated Surface Water ASR Systems.” Proceedings of the Aquifer Recharge Conference. Orlando, FL.

The NELAC Institute (TNI). n.d. Retrieved August 23, 2012 from .

NSF/ANSI 350-1-2011 (NSF) 2011b. Onsite Residential and Commercial Graywater Treatment Systems for Subsurface Discharge. National Sanitation Foundation, Ann Arbor, Michigan, June 2011. National Water Commission of Mexico. 2010. Statistics on Water in Mexico. CONAGUA. Mexico. Natural Resource Management Ministerial Council, Environment Protection and Heritage Council, and Australian Health Ministers’ Conference. 2006. Australian Guidelines for Water Recycling: Managing Health and Environmental Risks. Environment Protection Heritage Council. Canberra, Australia. Oasis Design. 2012. Graywater Policy Center. Retrieved July 2012 from . O’Connor, T. P., D. Rodrigo, and A. Cannan. 2010. “Total Water Management: The New Paradigm for Urban Water Resources Planning.” Proceedings of World Environmental and Water Resources Congress 2010. Providence, R.I. Pyne, R. D. G. 2005. Aquifer Storage Recovery: A Guide to Groundwater Recharge through Wells. 2nd edition. ASR Systems Publishing, Gainsville, FL. Rimer, A. 2009. “Graywater ‘Blues’ – The Perils of Its Use.” WateReuse Symposium, Seattle, WA. Rodrigo, D., E. J. López Calva, and A. Cannan. 2012. Total Water Management. EPA 600/R-12/551. U.S. Environmental Protection Agency. Washington, D.C.

Mirecki, J. E. 2004. Water-Quality Changes During Cycle Tests at Aquifer Storage Recovery (ASR) Systems of South Florida. ERDC/EL TR-04-8. U.S. Army Corps of Engineers. Vicksburg, MS.

Rose, J. B., D. E. Huffman, K. Riley, S. Farrah, J. Lukasik, and C. L. Hamann. (2001). “Reduction of Enteric Microorganisms at the Upper Occoquan Sewage Authority Water Reclamation Plant.” Water Environment Research. 73:711–720.

National Research Council. 2012. Water Reuse: Potential for Expanding the Nation's Water Supply Through Reuse of Municipal Wastewater. The National Academies Press: Washington, D.C.

San Antonio Water System (SAWS). 2006. Recycled Water Users’ Handbook. Retrieved July 2012 from Sheikh, B. 2010. White Paper on Graywater. WateReuse Association. Alexandria, VA.

2012 Guidelines for Water Reuse

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Chapter 2 | Planning and Management Considerations

Shrier, C. 2010. “Reclaimed Water ASR for Potable Re‐Use: The Next Frontier.” Proceedings of the Aquifer Recharge Conference. Orlando, FL.

for Design, Operation, and Maintenance of Waste Water Treatment Facilities. EPA 430/99-74-001. Environmental Protection Agency. Washington, D.C.

Stuyfzand, P. J. 1998. “Quality Changes upon Injection into Anoxic Aquifers in the Netherlands: Evaluation of 11 Experiments.” In J. H. Peters (Ed.), Artificial Recharge of Groundwater. A.A. Balkema. Rotterdam, Netherlands.

U.S. Green Building Council (USGBC). n.d. Accessed July 2012 from .

Texas Commission on Environmental Quality (TCEQ). 1997. Texas Administrative Code. Retrieved August, 2012, from . Toze, S., and J. Hanna. 2002. “The Survival Potential of Enteric Microbial Pathogens in a Treated Effluent ASR Project.” In Management of Aquifer Recharge for Sustainability. Balkema Publishers. Australia. U.S. Environmental Protection Agency (EPA). 2012. WaterSense: An EPA Partnership Program. Retrieved September 6, 2012 from . U.S. Environmental Protection Agency (EPA). 2006. Process Design Manual Land Treatment of Municipal Wastewater Effluents. EPA/625/R-06/016. Environmental Protection Agency, Office of Research and Development. Cincinnati, OH. U.S. Environmental Protection Agency (EPA). 2004. Guidelines for Water Reuse. EPA. 625/R04/108. Environmental Protection Agency. Washington, D.C. U.S. Environmental Protection Agency (EPA). 2003. CrossConnection Control Manual. EPA 816-R-03-002. Environmental Protection Agency, Office of Water, Washington, D.C. U.S. Environmental Protection Agency (EPA). 2001. Safe Drinking Water Act, Underground Injection Control (UIC) Program, Protecting Public Health and Drinking Water Resources. EPA. 816-H-01-003. Environmental Protection Agency. Washington, D.C.

Van Riper, C., G. Schlender, and M. Walther. 1998. “Evolution of Water Reuse Regulations in Washington State.” WateReuse Conference Proceedings. Denver, CO. Vandertulip, W. D. 2011a. “Are We Color Blind?” WEFTEC Proceedings. Los Angeles, CA. Vandertulip, W. D. 2011b. “Can We Support a National Water Utility Pipe Color Code?” WateReuse Symposium Proceeding. Phoenix, AZ. WateReuse Association (WRA). 2009. Manual of Practice, How to Develop a Water Reuse Program. WateReuse Association. Alexandria, VA. Water Environment Research Foundation (WERF). n.d. Case Study: Battery Park Urban Water Reuse. Water Environment Research Foundation. Alexandria, VA. WateReuse Research Foundation (WRRF). 2009. Selection and Testing of Tracers for Measuring Travel Times in Natural Systems Augmented with Treated Wastewater Effluent. WRF-05-007. WateReuse Research Foundation. Alexandria, VA. WateReuse Research Foundation (WRRF). 2007a. Extending the Integrated Resource Planning Process to Include Water Reuse and Other Nontraditional Water Sources. WRF-04-010. WateReuse Research Foundation. Alexandria, VA. WateReuse Research Foundation (WRRF). 2007b. Reclaimed Water Aquifer Storage and Recovery: Potential Changes in Water Quality. WRF-03-009-01. WateReuse Foundation. Alexandria, VA.

U.S. Environmental Protection Agency (EPA). 1974. Design Criteria for Mechanical, Electrical, and Fluid System and Component Reliability – Supplement to Federal Guidelines

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CHAPTER 3 Types of Reuse Applications The United States has achieved numerous accomplishments toward expanding the use of reclaimed water and extending water resources for many communities. Yet, there is room for improvement in terms of the total amount of water reused, distribution of reclaimed water use throughout the country, and the adoption of new, higher quality uses. A report by the NRC Water Science & Technology Board titled Water Reuse: Potential for Expanding the Nation’s Water Supply Through Reuse of Municipal Wastewater estimates that as much as 12 bgd (45 MCM/d) of the 32 bgd (121 MCM/d) produced in the United States can be beneficially reclaimed and reused (NRC, 2012). Recent estimates indicate that approximately 7 to 8 percent of wastewater is reused in the United States (Miller, 2006 and GWI, 2009) (Figure 3-1). Therefore, there is tremendous potential for expanding the use of reclaimed water in the future.

Approximately 7-8% reclaimed

The United States produces approximately 32 billion gallons of municipal effluent per day.

Figure 3-1 Reclaimed water use in the United States

Outside of the United States, there are examples of countries with different water resource demands that greatly exceed this percentage. Several countries, including Australia and Singapore, have established goals for reuse, expressed in terms of the percentage of municipal wastewater effluent that is treated to a higher quality and beneficially reused. Australia currently reuses approximately 8 percent of its treated

2012 Guidelines for Water Reuse

wastewater with a goal of reusing 30 percent by 2015. Saudi Arabia currently reuses 16 percent with a goal to increase reuse to 65 percent by 2016. Singapore reuses 30 percent and has long-term planning in place to diversify its raw water supplies and reduce dependence on supplies from outside sources (i.e., Malaysia). Israel has attained the highest national percentage by beneficially reusing 70 percent of the generated domestic wastewater. The last comprehensive survey of water reuse in the United States was conducted in 1995 by the U.S. Geological Survey (USGS); more recently, the USGS compiled water use data from 2005 (Solley et al., 1998). Estimates of wastewater reuse were compiled by some states for the industrial, thermoelectric, and irrigation categories but were not reported because of the small volumes of water compared to the totals (Kenny et al., 2009). The study revealed that 95 percent of water reuse occurred in just four states: Arizona, California, Florida, and Texas. This is now estimated to be less than 90 percent due to increased water reuse in several other states, especially Nevada, Colorado, New Mexico, Virginia, Washington, and Oregon. In addition, reuse is now practiced in the MidAtlantic and Northeast regions of the United States, with a number of water reuse facilities in New Jersey, Pennsylvania, New York, and Massachusetts. Production and distribution of reclaimed water varies regionally by categories of use and depends on historical and emerging drivers, as described in Chapter 5. Table 3-1 shows the distribution of reclaimed water use for California and Florida—the two largest users of reclaimed water in the United States. Although California reused 669,000 ac-ft (825 MCM) of water in 2009, coastal communities were an untapped source of reclaimed water by discharging 3.5 million ac-ft (4,300 MCM) of highly-treated wastewater to the Pacific Ocean. The challenge for coastal communities then shifts from adequate supply to an ability to distribute the new source water from the coast through a highly-developed urbanized area to points of use.

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Chapter 3 | Types of Reuse Applications

Table 3-1 Distribution of reclaimed water in California (Baydal, 2009) and Florida (FDEP, 2011) California Reuse Category (% Use in 2009)

Florida (% Use in 2010)

Agricultural

29

11

Urban reuse (landscape irrigation, golf courses)

19

55

Groundwater Recharge

5

14

Seawater Intrusion Barrier

8

-

Industrial Reuse

7

13

Natural Systems and Other Uses

23

9

Recreational Impoundments

7

-

Geothermal Energy

2

-

Irrigation

The distribution of reclaimed water use in the United States is a reflection of regional characteristics, and these differences are explored in greater detail in Chapter 5. Understanding the planning considerations and requirements for reuse types is critical to developing a successful program. Thus, this chapter highlights major types of reuse, including agricultural, industrial, environmental, recreational, and potable reuse; examples of these applications across the United States and internationally are provided for these applications.

3.1 Urban Reuse

While there are several major categories of reuse, in the United States urban reuse is one of the highest volume uses. Applications such as recreational field and golf course irrigation, landscape irrigation, and other applications, including fire protection and toilet flushing, are important components of the reclaimed water portfolio of many urban reuse programs. Urban reuse is often divided into applications that are either accessible to the public or have restricted access, in settings where public access is controlled or restricted by physical or institutional barriers, such as fences or temporal access restriction. Additional information on the treatment and monitoring requirements for both types of urban reuse is provided in Chapter 6. Additionally, because urban reuse comprises such a large fraction of the total reclaimed water use, detailed information regarding planning and management of reclaimed water supplies and systems that include urban reuse is provided in Chapter 2.

3.1.1 Golf Courses and Recreational Field Irrigation In order to maximize the use of potable water in resource-limited systems, communities are working to identify alternatives for minimizing nonpotable 3-2

consumption by supplying reclaimed water for reuse. When used to irrigate residential areas, golf courses, public school yards, and parks, reclaimed water receives treatment and high-level disinfection and is not considered a threat to public health. However, the water quality of reclaimed water differs from that of drinking quality water or rainfall and should be considered when used for irrigation and other industrial reuse applications. Of particular importance are the salts and nutrients in reclaimed water, and special management practices for both end uses may be required depending on the concentrations in the reclaimed water. For example, in some areas where landscaping is irrigated, the salt sensitivity of the irrigated plants should be considered. The 2004 Guidelines for Water Reuse (EPA, 2004) identified irrigation of golf courses as one of several typical urban water reuse practices. While this was and still is an attractive use for reclaimed water as large quantities can be beneficially used by one user, there are operational practices and cautions that planners should consider. Between September 2000 and December 2004, AWWA conducted a survey of reclaimed water use practices on golf courses (Grinnell and Janga, 2004). Results of this survey were compiled from 180 responses from seven states, Canada, and Mexico. Two-thirds of the responses were from Florida, California, and Arizona. Combined with data from the Golf Course Superintendents Association of America (GCSAA), AWWA estimated in 2004 that 2,900 of the 18,100 golf courses surveyed were using reclaimed water, a 600 percent increase from 1994 data. Although most comments were positive, some respondents expressed concern regarding algal problems in ponds, changes in course treatment, and increased turf management.

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Chapter 3 | Types of Reuse Applications

A more recent survey in 2006 by the GCSAA and the Environmental Institute for Golf (EIFG) requested input from superintendents at 16,797 courses and received response from 2,548 (GCSSA and EIFG, 2009). Based on this survey, an estimated 12 percent of golf courses in the United States use reclaimed water, with more courses in the southwest (37 percent) and southeast (24 percent) practicing reuse. In fact, the most recent state survey for Florida in 2010 (FDEP, 2011) listed 525 golf courses using nearly 118 mgd (5170 L/s) of reclaimed water, representing about 17.9 percent of the daily reuse within the state. This continued application of reuse to golf courses is exemplified in the following case studies: 

US-FL-Pompano Beach



US-FL-Marco Island



US-TX-Landscape Study



Australia-Victoria

The most common reason identified by golf courses for not using reclaimed water for irrigation was the lack of a source for reclaimed water (53 percent of respondents) (FDEP, 2011). It was also not a surprise that the poorest water quality identified by respondents was in the southwest where there was typically higher TDS and salinity concerns. With lower water quality, systems in the southwest and southeast were most likely to use wetting agents and fertigation systems. To address some of the water quality concerns, turfgrass research has been conducted to determine the most salt-tolerant species for a geographic area and soil type.

ions concentrations increased, indicating a need for long-term monitoring, scheduled leaching, and/or supplemental treatment to maintain good soil conditions. During the dormant season for the two grasses, the study recommended applications of reclaimed water at no more than the evapotranspiration rate to preclude nitrate transport below the root zone. Golf course turf studies have been conducted for over 30 years and there are several publications that have been developed for the USGA and GCSAA related to use of reclaimed water for golf course irrigation. Reclaimed water for this purpose has been referred to as “purple gold,” especially in the southwestern United States where golf course turf depends on irrigation (Harivandi, 2011). Recommendations for use of reclaimed water for turfgrass irrigation focus on quality limits of reclaimed water and monitoring. For reclaimed water that exceeds the recommended criteria presented in Table 3-2, slight to moderate use restrictions would apply (Harivandi, 2011). Even though the poorest quality reclaimed water with respect to TDS is produced in the southwest, it is there where the greatest golf course reuse occurs. In addition to selecting salt-tolerant grasses such as Alkali, Bermuda, Fineleaf, St. Augustine, Zoysia, Saltgrass, Seashore, or Paspalum, many facilities have implemented solutions to mitigate adverse impacts of challenging water quality. Some of these practices include: 

Applying extra water to leach excess salts below the turfgrass root zone

In San Antonio, SAWS and Texas A&M University  Providing adequate drainage conducted a 2-year test (2003 to 2004) that compared the application rates of potable (control) water and reclaimed water on 18 plots of Tifway Table 3-2 Interpretation of reclaimed water quality Bermuda grass and Jamur zoysia grass Degree of Restriction on Use (Thomas et al., 2006). The study evaluated Slight to Parameter Units None Moderate Severe leachate quality, soil ion retention, and grass Salinity quality. Of particular concern was the potential -1 Ecw dS m < 0.7 0.7 - 3.0 > 3.0 transport through the root zone of nitrate, TDS mg/L < 450 450 - 2,000 > 2,000 which could potentially percolate in the local Ion Toxicity SAR <3 3-9 >9 karst geology to the sole source Edwards Sodium (Na) meq/L <3 >3 Aquifer. Results indicated both grasses were Root Absorption mg/L < 70 > 70 Foliar Absorption meq/L <2 2 - 10 > 10 well adapted to using the SAWS reclaimed Chloride (Cl) mg/L < 70 70 355 > 355 water; the grasses maintained high quality but Root Absorption meq/L <3 >3 did not uptake all of the nitrogen applied during Foliar Absorption mg/L < 100 > 100 the December to February dormant period. Soil Boron mg/L < 1.0 1.0 - 2.0 > 2.0 pH

2012 Guidelines for Water Reuse

6.5 - 8.4

3-3

Chapter 3 | Types of Reuse Applications



Modifying turf management practices



Modifying the root zone mixture



Blending irrigation waters



Using amendments

A study by Virginia Polytechnic Institute and State University investigated nutrient management practices and application rates of nitrogen to turf and crops in Virginia (Hall et al., 2009). This study found that 50 percent of responding golf course superintendents were applying nitrogen to greens at rates in excess of turfgrass needs (> 5.1 lbs of water soluble nitrogen per 2 1,000 ft ). With only 16 percent of respondents providing supplemental irrigation, no significant problems were detected, but the study did suggest education programs to reduce nitrogen application rates in several turf management areas to minimize potential for transport of nutrients off-site. In addition to managing water quality, many facilities are required to implement special management practices where reuse is implemented to minimize the potential of cross-connection of water sources. For example, golf courses in San Antonio are required to include a double-check valve on the reclaimed water supply to the property to prevent backflow of reclaimed water into the SAWS potable water distribution system. Golf courses are also required to include a reduced pressure principal backflow preventer on the potable water supply to the property. Irrigation of public parks and recreation centers, athletic fields, school yards and playing fields, and landscaped areas surrounding public buildings and facilities plays an important role in reuse. The considerations for irrigating these areas are much like those for golf courses. However, as discussed in Chapter 4, many states have regulations that specifically address urban use of reclaimed water.

world’s current populations without adequate irrigation (Kenny et al., 2009). By 2050, rising population and incomes are expected to demand 70 percent more production, compared to 2009 levels. Increased production is projected to come primarily from intensification on existing cultivated land, with irrigation playing an important role (FAO, 2011). In the United States, agricultural irrigation totals about 128,000 mgd (5.6 M L/s) (Kenny et al., 2009), which represents approximately 37 percent of all freshwater withdrawals. Confounding the agricultural water supply issue are the recent increases in midwestern and southeastern inter-annual climate variability that has led to more severe droughts, making issues of agricultural water reliability a greater national challenge. In many regions of the United States, expanding urban populations and rising demands for water from municipal and industrial sectors now compete for water supplies traditionally reserved for irrigated agriculture. In other areas, irrigation water supplies are being depleted by agricultural use. These shifts in the availability and quality of traditional water resources could have dramatic impacts on the longterm supply of food and fiber in the United States (Dobrowolski et al., 2004, 2008). Agricultural use of reclaimed water has a long history and currently represents a significant percentage of the reclaimed water used in the United States. Therefore, the U.S. Department of Agriculture/National Institute of Food and Agriculture (USDA/NIFA) has made funding for water reuse one of its key priorities; additional discussion of the USDA/NIFA research is provided in Appendix A. Reclaimed water from municipal and agricultural sources provides many advantages, including: 

The supply of reclaimed water is highly reliable and typically increases with population growth.



The cost of treating wastewater to secondary (and sometimes even higher) standards is generally lower than the cost of potable water from unconventional water sources (e.g., desalination).



The option of allocating reclaimed water to irrigation is often the preferred and least expensive management alternative for municipalities.

3.2 Agricultural Reuse

Water availability is central to the success of agricultural enterprises domestically and globally and cuts across multiple disciplines related to human health, food safety, economics, sociology, behavioral studies, and environmental sciences (O’Neill and Dobrowolski, 2011). As such, almost 60 percent of all the world’s freshwater withdrawals go towards irrigation uses. Farming could not provide food for the

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Chapter 3 | Types of Reuse Applications

 

Reclaimed water is an alternative to supplement and extend freshwater sources for irrigation. In many locales, reclaimed water might be the highest quality water available to farmers, and could represent an inexpensive source of fertilizer. However, this advantage is conditional on proper quantities and timing of water and nutrients. Depending on the stage of growth, excess nutrients can negatively affect yields (Dobrowolski et al., 2008).

Use of reclaimed water for agriculture has been widely supported by regulatory and institutional policies. In 2009, for example, California adopted both the Recycled Water Policy and “Water Recycling Criteria.” Both policies promote the use of recycled water in agriculture (SWRCB, 2009 and CDPH, 2009). In response to an unprecedented water crisis brought about by the collapse of the Bay-Delta ecosystem, climate change, continuing population growth, and a severe drought on the Colorado River, the California State Water Resources Control Board (SWRCB) was prompted to “exercise the authority granted to them by the Legislature to the fullest extent possible to encourage the use of recycled water, consistent with state and federal water quality laws.” As a result, future recycled water use in California is estimated to reach 2 million ac-ft/yr (2,500 MCM/yr) by 2020, and 3 million ac-ft/yr (3,700 MCM/yr) by 2030 (SWRCB, 2009). As a result, California presently recycles about 650,000 ac-ft/yr (800 MCM/yr), an amount that has doubled in the last 20 years (SWRCB, 2010) with agriculture as the top recycled water user. Other

5%

4% 2%

7%

reclaimed water uses are shown in Figure 3-2. In Florida, promotion of reclaimed water began in 1966; currently, 63 of 67 counties have utilities with reclaimed water systems. One of the largest and most visible reclaimed water projects is known as WATER CONSERV II in Orange County, Fla., where farmers have used reclaimed water for citrus irrigation since 1986. Another long-serving example of reclaimed water use in the United States is the city of Lubbock, Texas, where reclaimed water has been used to irrigate cotton, grain sorghum, and wheat since 1938. In addition, reclaimed water is a significant part of the agricultural water sustainability portfolio in Arizona, Colorado, and Nevada (Table 3-3). Table 3-3. Nationwide reuse summaries of reclaimed water use in agricultural irrigation (adapted from Bryk et al., 2011) Annual Agricultural Reuse Volume State Arizona California Colorado Florida Idaho North Carolina Nevada Texas Utah Washington Wyoming

mgd 23 270 2.97 256 0.27 1.0 13.4 19.4 0.81 0.02 0.89

1000 ac-ft/yr 26 303 3 287 0.3 1 15 22 1 0.03 1

Agriculture Irrigation: 29% 29%

Other: 20% Landscape Irrigation/Golf Course Irrigation: 18% Seawater Barrier: 8%

7%

Commercial & Industrial: 7% Recreational Impoundment: 7% Groundwater Recharge: 5%

8%

Natural System Restoration, Wetlands, Wildlife Habitat: 4% Geothermal/Energy Production: 2% 18%

20%

Indirect Potable Reuse: 0% (not visible) Surface Water Augmentation: 0% (not visible)

Figure 3-2 Nationwide reuse summaries of reclaimed water use in agricultural irrigation (adapted from Bryk, et al., 2011) 2012 Guidelines for Water Reuse

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Chapter 3 | Types of Reuse Applications

3.2.1 Agricultural Reuse Standards

3.2.2 Agricultural Reuse Water Quality

Different regions and governmental agencies, both in the United States and globally, have adopted a variety of standards for use of reclaimed water for irrigation of crops. These rules and regulations have been developed primarily to protect public health and water resources; specific crop water quality requirements must be developed with the end users. The standards that have been adopted in the United States have proven protective of public health in spite of the vast differences in their stringency.

Because agricultural reuse is one of the most significant uses of reclaimed water globally, it is critical to understand the factors that determine success or failure of a farming operation dependent upon reclaimed water for irrigation. The same concerns for chemical constituents are applicable to all sources of irrigation water, and reclaimed water is no exception. Several factors, including soil-plant-water interactions (irrigation water quality, plant sensitivity and tolerance, soil characteristics, irrigation management practices, and drainage) are important in crop production. For example, under poor drainage conditions, even the most generally suitable water quality used for irrigation may lead to crop failure. On the other hand, welldrained soils, combined with a proper leaching fraction in the irrigation regime, can tolerate relatively high salinity in the irrigation water, whether it is reclaimed water or brackish groundwater.

The WHO guidelines (WHO, 2006) for irrigation with reclaimed water, widely adopted in Europe and other regions, is a science-based standard that has been successfully applied to irrigation reuse applications throughout the world. And, the California Water Recycling Criteria (Title 22 of the state Code of Regulations) require the most stringent water quality standards with respect to microbial inactivation (total coliform < 2.2 cfu/100 mL). California Water Recycling Criteria requires a specific treatment process train for production of recycled water for unrestricted food crop irrigation that includes, at a minimum, filtration and disinfection that meets the state process requirements. Irrigation of crops (both food and non-food) with untreated wastewater is widely practiced in many parts of the developing world with accompanying adverse public health outcomes. Nonetheless, this practice represents an economic necessity for many farming communities and for the rapidly expanding population at large, much of which is dependent on locally grown crops. Various international aid organizations have mobilized to improve upon these irrigation practices and provide barriers against transmission of diseasecarrying agents (Scott et al., 2004). Regulated and well-managed irrigation under WHO guidelines (or similar standards) can be protective of public health and the health of farm workers. More restrictive regulations, such as those in California and Italy, while amply protective, are potentially prohibitively expensive in some economic contexts without necessarily improving the public health outcome. Additional discussion of the implications of stringent regulations in economically challenged contexts is provided in Chapter 9. The regulations, guidelines, and standards that are relevant to agricultural reuse applications in the United States, as well as a summary of standards by reuse type, are provided in Chapter 4.

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Thus, when considering the use of reclaimed water in agriculture, it is important to identify the key constituents of concern for agricultural irrigation. Plant sensitivity is generally a function of a plant’s tolerance to constituents encountered in the root zone or deposited on the foliage, and reclaimed water tends to have higher concentrations of some of these constituents than the groundwater or surface water sources from which the water supply is drawn. The types and concentrations of constituents in reclaimed water depend on the municipal water supply, the influent waste streams (i.e., domestic and industrial contributions), the amount and composition of infiltration in the wastewater collection system, the treatment processes, and the type of storage facilities. Determining the suitability of a given reclaimed water supply for use as a supply of agricultural irrigation is, in part, site-specific, and agronomic investigations are recommended before implementing an agricultural reuse program. To assess quality of reclaimed water with respect to salinity, the Food and Agriculture Organization (FAO) (1985) has published recommendations for agricultural irrigation with degraded water; this information provides a guide to making an initial assessment for application of reclaimed water in an agricultural setting. A summary of these recommendations is provided in Table 3-4. There are a number of assumptions in these guidelines, which are intended to cover the wide range of conditions that may be

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Chapter 3 | Types of Reuse Applications

encountered in irrigated agriculture practices; where sufficient experience, field trials, research, or observations are available, the guidelines may be modified to address local conditions more closely. 

Yield Potential: Full production capability of all crops, without the use of special practices, is assumed when the guidelines indicate no restrictions on use. A “restriction on use” indicates that choice of crop may be limited or that special management may be needed to maintain full production capability; it does not indicate that the water is unsuitable for use.



Site Conditions: Soil texture ranges from sandy-loam to clay-loam with good internal drainage; the climate is semi-arid to arid, and rainfall is low. Rainfall does not play a significant role in meeting crop water demand or leaching

requirement. Drainage is assumed to be good, with no uncontrolled shallow water table present within 6 ft (2 m) of the surface. 

Method of Irrigation: Normal surface or sprinkler irrigation methods are used; water is applied infrequently, as needed; and the crop utilizes a considerable portion of the available stored soil-water (50 percent or more) before the next irrigation. At least 15 percent of the applied water percolates below the root zone. The guidelines are too restrictive for specialized irrigation methods, such as localized drip irrigation, which results in near daily or frequent irrigations, but are applicable for subsurface irrigation if surface-applied leaching satisfies the leaching requirements.

Table 3-4 Guidelines for interpretation of water quality for irrigation Potential Irrigation Problem

2

1

Units

Degree of Restriction on Irrigation None Slight to Moderate Severe

Salinity (affects crop water availability) ECw dS/m < 0.7 0.7 – 3.0 TDS mg/L < 450 450 – 2000 3 Infiltration (affects infiltration rate of water into the soil; evaluate using ECw and SAR together) 0–3 > 0.7 0.7 – 0.2 3–6 > 1.2 1.2 – 0.3 and ECw = 6 – 12 > 1.9 1.9 – 0.5 SAR 12 – 20 > 2.9 2.9 – 1.3 20 – 40 > 5.0 5.0 – 2.9 Specific Ion Toxicity (affects sensitive crops) 4 Sodium (Na) surface irrigation SAR <3 3–9 sprinkler irrigation meq/l <3 >3 4 Chloride (Cl) surface irrigation meq/l <4 4 – 10 sprinkler irrigation meq/l <3 >3 Boron (B) mg/L < 0.7 0.7 – 3.0

> 3.0 > 2000 < 0.2 < 0.3 < 0.5 < 1.3 < 2.9

>9

> 10 > 3.0

Miscellaneous Effects (affects susceptible crops) Nitrate (NO3-N) mg/L <5 5 – 30 > 30 Bicarbonate (HCO3) meq/L < 1.5 1.5 – 8.5 > 8.5 Normal Range 6.5 – 8.4 pH 1 Adapted from FAO (1985) 2 ECw means electrical conductivity, a measure of the water salinity, reported in deciSiemens per meter at 25°C (dS/m) or in millimhos per centimeter (mmho/cm); both are equivalent. 3 SAR is the sodium adsorption ratio; at a given SAR, infiltration rate increases as water salinity increases. 4 For surface irrigation, most tree crops and woody plants are sensitive to sodium and chloride; most annual crops are not sensitive. With overhead sprinkler irrigation and low humidity (< 30 percent), sodium and chloride may be absorbed through the leaves of sensitive crops.

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Restriction on Use: The “Restriction on Use” shown in Table 3-4 is divided into three degrees of severity: none, slight to moderate, and severe. The divisions are somewhat arbitrary because changes occur gradually, and there is no clear-cut breaking point. A change of 10 to 20 percent above or below a guideline value has little significance if considered in proper perspective with other factors affecting yield. Field studies, research trials, and observations have led to these divisions, but management skill of the water user can alter the way in which the divisions are interpreted for a particular application. Values shown are applicable under normal field conditions prevailing in most irrigated areas in the arid and semi-arid regions of the world.

3.2.2.1 Salinity and Chlorine Residual As noted in Table 3-4, salinity is a key parameter in determining the suitability of the water to be used for irrigation, and the wide variability of salinity tolerance in plants can confound the issue of establishing salinity criteria. All waters used for irrigation contain salt to some degree; therefore, salts (both cations and anions) will build up without proper drainage. Agricultural Salinity Assessment and Management, which is the second edition of ASCE MOP 71 (American Society of Civil Engineers [ASCE], 2012) provides additional information on worldwide salinity and trace element management in irrigated agriculture and water supplies. This updated edition provides a reference to help sustain irrigated agriculture and integrates contemporary concepts and management practices. It covers technical and scientific aspects of agricultural salinity management as well as environmental, economic, and legal concerns. However, because salinity management is such an important consideration in agricultural reuse, a brief discussion of the topic is provided here. Salinity is determined by measuring the electrical conductivity (EC) and/or the TDS in the water; however, for most agricultural measurements, TDS is reported as EC. The use of high TDS water for irrigation will tend to increase the salinity of the groundwater if not properly managed. The extent of salt accumulation in the soil depends on the concentration of salts in the irrigation water and the rate at which salts are removed by leaching. Using

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TDS as a measure of salinity, no detrimental effects are usually noticed below 500 mg/L. Between 500 and 1,000 mg/L, TDS in irrigation water can affect sensitive plants; at concentrations above 1,000 to 2,000 mg/L, TDS levels can affect many crops, so careful management practices should be followed. Several case study examples demonstrate the importance and implementation of TDS management for use of reclaimed water for irrigation [US-TX-Landscape Study; US-CO-Denver Soil; US-CA-Monterey; and Israel/Jordan-AWT Crop Irrigation]. At TDS concentrations greater than 2,000 mg/L, water can be used regularly only for salt-tolerant plants on highly permeable soils. A study was conducted in Israel to address the impact of reclaimed water containing high levels of salts, including ions specifically toxic to plants, such as sodium (Na) and boron (B); results are provided in a case study summary from Israel and Jordan [Israel and Jordan - Brackish Irrigation]. With respect to chlorine residuals, which may be present as a disinfection residual, free chlorine at concentrations less than 1 mg/L usually poses no problem to plants; chlorine at concentrations greater than 5 mg/L can cause severe damage to most plants. However, some sensitive crops may be damaged at levels as low as 0.05 mg/L. For example, some woody crops may accumulate chlorine in the tissue up to toxic levels; further, excessive chlorine residuals can have a similar leaf-burning effect that is caused by sodium and chloride when reclaimed water is sprayed directly onto foliage. Low-angle spray heads or surface irrigation options can reduce the leaf-burning impact.

3.2.2.2 Trace Elements and Nutrients Thirteen mineral nutrients are required for plant growth, and fertilizers are added to soils with inadequate concentrations of these nutrients. Mineral nutrients are divided into two groups: macronutrients (primary and secondary) and micronutrients. Primary macronutrients, which include nitrogen, phosphorus, and potassium, are often lacking from the soil because plants use large amounts for growth and survival. The secondary macronutrients include calcium, magnesium, and sulfur. Micronutrients—boron, copper, iron, chloride, manganese, molybdenum, and zinc—are elements essential for plant growth in small quantities and are often referred to as trace elements. While these trace elements are necessary for plant growth, excessive concentrations can be toxic.

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The recommended maximum concentrations of constituents in reclaimed water for “long-term continuous use on all soils” are set conservatively based on application to sandy soils that have adsorption capacity. These values have been established below the concentrations that produce toxicity when the most sensitive plants are grown in nutrient solutions or sand cultures to which the constituent has been added. Thus, if the suggested limit is exceeded, phytotoxicity will not necessarily occur; however, most of the elements are readily fixed or tied up in soil and accumulate with time such that repeated application in excess of suggested levels is likely to induce phytotoxicity. The trace element and nutrients criteria recommended for fine-textured neutral and alkaline soils with high capacities to remove the different pollutant elements are provided in

Table 3-5. These criteria, were previously presented in 2004, however, based on maintaining sustainable application of reclaimed water for irrigation, recommendations have included removal of increased concentrations for short-term use, which is also consistent with recommendations of the FAO in Water Quality for Agriculture (FAO, 1985). There are also related effects of pH on plant growth, which are primarily related to its influence on metal toxicity, as shown in Table 3-5; as a result, a pH range of 6-8 is recommended for reclaimed water used for irrigation. Of the macronutrients, nitrogen is the most widely applied as a fertilizer. Nitrogen is important in helping plants with rapid growth, increasing seed and fruit production, and improving the quality of leaf and forage crops. Like nitrogen, phosphorus effects rapid

Table 3-5 Recommended water quality criteria for irrigation

Constituent

Maximum Concentrations for Irrigation (mg/L)

Aluminum

5.0

Arsenic

0.10

Beryllium

0.10

Boron

0.75

Cadmium

0.01

Chromium

0.1

Cobalt Copper Fluoride

0.05 0.2 1.0

Iron

5.0

Lead

5.0

Lithium

2.5

Manganese

0.2

Molybdenum

0.01

Nickel

0.2

Selenium

0.02

Tin, Tungsten, and Titanium Vanadium

0.1

Zinc

2.0

-

2012 Guidelines for Water Reuse

Remarks Can cause nonproductiveness in acid soils, but soils at pH 5.5 to 8.0 will precipitate the ion and eliminate toxicity Toxicity to plants varies widely, ranging from 12 mg/L for Sudan grass to less than 0.05 mg/L for rice Toxicity to plants varies widely, ranging from 5 mg/L for kale to 0.5 mg/L for bush beans Essential to plant growth; sufficient quantities in reclaimed water to correct soil deficiencies. Optimum yields obtained at few-tenths mg/L; toxic to sensitive plants (e.g., citrus) at 1 mg/L. Most grasses are tolerant at 2.0 - 10 mg/L Toxic to beans, beets, and turnips at concentrations as low as 0.1 mg/L; conservative limits are recommended Not generally recognized as an essential element; due to lack of toxicity data, conservative limits are recommended Toxic to tomatoes at 0.1 mg/L; tends to be inactivated by neutral and alkaline soils Toxic to a number of plants at 0.1 to 1.0 mg/L Inactivated by neutral and alkaline soils Not toxic in aerated soils, but can contribute to soil acidification and loss of phosphorus and molybdenum Can inhibit plant cell growth at very high concentrations Tolerated by most crops up to 5 mg/L; mobile in soil. Toxic to citrus at low doses— recommended limit is 0.075 mg/L Toxic to a number of crops at few-tenths to few mg/L in acidic soils Nontoxic to plants; can be toxic to livestock if forage is grown in soils with high molybdenum Toxic to a number of plants at 0.5 to 1.0 mg/L; reduced toxicity at neutral or alkaline pH Toxic to plants at low concentrations and to livestock if forage is grown in soils with low levels of selenium Excluded by plants; specific tolerance levels unknown Toxic to many plants at relatively low concentrations Toxic to many plants at widely varying concentrations; reduced toxicity at increased pH (6 or above) and in fine-textured or organic soils

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growth of plants and is important for blooming and root growth. Potassium is absorbed by plants in larger amounts than any other mineral element except nitrogen and, in some cases, calcium; the role of this nutrient is key in fruit quality and reduction of diseases. All of these nutrients can be obtained from application of reclaimed water, so there is added value in using reclaimed water. However, in light of ever-increasing regulatory requirements for nutrient removal to address loads to receiving streams, nitrogen and/or phosphorus are often removed in municipal WWTPs. As a result of nutrient removal, even if reclaimed water is applied in adequate quantities to provide trace nutrients, fertilizer application may still be required. Where appropriate for crop use, increased supply of reclaimed water for irrigation could provide needed nutrients for crops while concurrently reducing nutrient load to the receiving stream. Nutrients, such as nitrogen and phosphorus, may contain beneficial qualities for irrigation. In a Canadian case study, the authors provided insight into costeffective advantages of diverting these nutrients from Lake Simcoe [Canada-Nutrient Transfer].

preliminary design stage of a project to ensure the proposed water reclamation system is feasible. A recommended list of considerations for agricultural reuse projects is provided below: 

Compatibility of agricultural operations with reclaimed water may warrant site-specific investigations to reveal compatibility issues that may arise when switching from traditional water supplies to reclaimed water. For example, reclaimed water treated to secondary standards may not be suitable for use in drip irrigation systems as the suspended solids in the reclaimed water can increase clogging.



There are differences in agricultural and municipal system reliability requirements. For example, distribution pipe pressure ratings for agriculture are close to that of the expected working pressure. Additionally, pump capacity redundancy in municipal systems is installed in the event of a failure; however, this is not common practice in agricultural operations.



Because reclaimed water quality is directly linked to crops that may be produced with that water, there may be additional regulatory controls that dictate when irrigation is applied and who is allowed on the property being irrigated. Examples of regulatory controls include modifications to irrigation systems to prevent contact with edible crops as required in Florida, Texas, and other states.



It also may be undesirable to use secondary quality reclaimed water where irrigation equipment results in aerosols, particularly where the area under irrigation is adjacent to the property boundary.



Regular communication between the end user and reclaimed water supplier is critical to a successful program, as it allows issues to be addressed as they arise.

3.2.2.3 Operational Considerations for Agricultural Reuse A municipal wastewater treatment facility and an agricultural operation have little in common, except that one entity supplies the water and the other uses it. Understanding how these two enterprises function is critical to developing a successful agricultural reuse system. First, operators of the municipal facility must understand that the demand for irrigation water will vary throughout the year as a function of rainfall and normal seasonal agricultural operations. Experience has shown that attempts to deliver a fixed volume of water for agricultural applications, independent of the actual need for irrigation water, rarely survive the first rainy season. Experience also suggests that asking the municipal or agricultural entity to take on the duties of the other party can cause problems. For example, farmers are typically not well suited to navigate the regulatory requirements to obtain a permit for use of reclaimed water. Likewise, a municipality is not set up to respond to changes in the agricultural market. There are many differences between municipal and agricultural operations that may not be apparent until the water reclamation system goes into operation. Consideration of these differences is needed at the

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3.2.3 Irrigation of Food Crops Irrigation of food crops with reclaimed water is common both in the United States and globally. However, there are “resource constrained” regions where untreated wastewater and inadequately-treated reclaimed water, sometimes mixed with river water, is used for irrigation of food crops—with devastating

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gastrointestinal disease consequences for consumers of the crops. As a result, the WHO guidelines provide specific procedures for minimizing these risks in most regions of the world (WHO, 2006). These regulations for food crop irrigation with reclaimed water are intended to minimize risks of microbial contamination of the crops, especially those grown for raw consumption, such as lettuce, cucumbers, and various fruits. The regulations specify treatment processes, water quality standards, and monitoring regimes that minimize risks for use of reclaimed water for irrigation of crops that are ingested by humans. Further discussion on global water reuse is provided in Chapter 9. Additional discussion of state regulatory guidelines and requirements for irrigation of food crops with reclaimed water is also provided in Section 4.5.2.3. An example of large-scale recycled water irrigation for raw-eaten food crops is in Monterey County, Calif. [US-CA-Monterey]. More than 5,000 ha of lettuce, broccoli, cauliflower, fennel, celery, strawberries, and artichokes have been irrigated with recycled water for more than a decade (Figure 3-3). This large-scale use of recycled water was preceded by an intensive, 11year pilot study to determine whether or not the use of disinfected filtered recycled water for irrigation of raweaten food crops would be safe for the consumer, the farmer, and the environment (Sheikh et al., 1990). Results of this project have shown that food crops are protected against pathogenic organisms, such as Giardia and Cryptosporidium (Sheikh et al., 1999). Marketing of produce from farms in northern Monterey County has been successful and profitable, although the local farmers initially feared customer backlash and rejection of produce irrigated with “sewer water.” As a result, farmers insisted that the produce not be labeled as having been irrigated with recycled water. The Monterey Regional Water Pollution Control Agency—producer/supplier of the recycled water— works closely with the farming community and has a contingency plan in place to address claims arising from an epidemic that might be traced to or associated with the fields using recycled water. Over the 13 years of irrigation (as of December 2011), there have been no such associations.

projects in other parts of the United States. and throughout the world [US-CA-Temecula, US-WA-King Argentina-Mendoza, Israel/Palestinian County, Territories/Jordan-Olive Irrigation, Senegal-Dakar, Vietnam-Hanoi]. In eastern Sicily (Italy), Cirelli et al. (2012) showed that reclaimed water treated at constructed wetlands could be used for edible food crops in Mediterranean countries and other arid and semi-arid regions that are confronting increasing water shortages. In addition to demonstrating that food crops were safe for human consumption, some crops showed higher yields (by approximately 20 percent) using reclaimed water when compared with controls supplied with freshwater.

3.2.4 Irrigation of Processed Food Crops and Non-Food Crops Irrigation of non-food crops (seed crops, industrial crops, processed food crops, fodder crops, orchard crops, etc.) with reclaimed water is far less complicated and more readily accepted by the agricultural community. Many countries use the WHO guidelines, which are risk-based and designed to provide a reasonable level of safety, assuming conservative levels of exposure by the public, the consumer, and farm workers. An example of reclaimed water use for non-food production is in Jordan, where reclaimed water is used on alfalfa plants, as shown in Figure 3-4 [Jordan-Irrigation]. In the United States, various states have adopted regulations for use of reclaimed water for non-food crop irrigation that are generally more relaxed than for food crops, allowing disinfected secondary effluent to be used in many cases. In any case, these are generally far more restrictive than the WHO guidelines. For example, California Water Recycling Criteria (Title 22) requires total coliform bacteria to be less than 23 MPN/100 mL for irrigation of non-food crops. This standard can be related to the concern for exposure of farm workers to the recycled water, although this level of water quality can be reliably achieved with welloperated secondary treatment processes with disinfection.

The success of this exemplary and pioneering project in Monterey County—from both technical and public acceptance points of view—has encouraged similar

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Figure 3-3 Monterey County vegetable fields irrigated with disinfected tertiary recycled water

Figure 3-4 Alfalfa irrigated with secondary effluent, Wadi Mousa (near Petra), Jordan

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Between the standards of California and WHO, there is a wide range of treatment standards throughout the world, as shown in Table 3-6. Additional discussion of state regulatory guidelines and requirements for irrigation of food crops with reclaimed water in the United States is also provided in Section 4.5.2.3. Table 3-6 Examples of global water quality standards for non-food crop irrigation Fecal Coliform Microbial Standards or Total or Guidelines by Coliform E. coli per State, Country, Region per 100 mL 100 mL Puglia (S. Italia) ≤ 10 California, Italy ≤ 23 Australia ≤ 10 Germany ≤ 100 ≤ 10 Washington State ≤ 240 Florida, Utah, Texas, EPA (Guidelines) ≤ 200 Arizona, New Mexico, Australia, Victoria, Mexico ≤ 1,000 Austria ≤ 2,000 Sicily ≤ 3,000 ≤ 1,000 Cyprus ≤ 3,000 WHO, Greece, Spain ≤ 10,000

3.2.5 Reclaimed Water for Livestock Watering Generally in the United States, reclaimed water is not utilized for direct consumption by livestock; however, de facto reuse often occurs. In this case, Table 3-7 is provided as a guide to acceptable water quality for livestock consumption. It should be noted that the information in Table 3-7 was developed from FAO 29 Water Quality in Agriculture, with more recent updates from Raisbeck et al. (2011) for molybdenum, sodium, and sulfate (FAO, 1985). These values are based on amounts of constituents normally found in surface and groundwater and are not necessarily the limits of animal tolerance. Additional sources of these substances may need to be considered along with drinking water, such as additional animal intake of these substances through feedstuffs. If concerns persist about safety for livestock, the local land-grant university should be consulted for additional information.

(fishing and boating) and full body contact (swimming and wading). With respect to water quality for recreational reuse that involves body contact, EPA has had recreational water quality criteria since 1986 for surface water that receives treated effluent regulated through the NPDES program. The criteria were developed to protect swimmers from illnesses from exposure to pathogens in recreational waters, as described in Section 6.3.1. EPA has also recently proposed new draft recreational water quality criteria in response to research findings in the fields of molecular biology, virology, and analytical chemistry (EPA, 2011). Table 3-7 Guidelines for concentrations of substances 1 in livestock drinking water Concentration Constituent (Symbol) (mg/L) Aluminium (Al) 5.0 Arsenic (As) 0.2 2 Beryllium (Be) 0.1 Boron (B) 5.0 Cadmium (Cd) 0.05 Chromium (Cr) 1.0 Cobalt (Co) 1.0 Copper (Cu) 0.5 Fluoride (F) 2.0 Iron (Fe) not needed 3 Lead (Pb) 0.1 4 Manganese (Mn) 0.05 Mercury (Hg) 0.01 Molybdenum (Mo) 0.3 Nitrate + Nitrite (NO3-N + NO2-N) 100 Nitrite (NO2-N) 10.0 Selenium (Se) 0.05 5 Sodium (Na) 1000 6 Sulfate (as SO4) 1000 Vanadium (V) 0.10 Zinc (Zn) 24.0 1 Adapted from FAO (1985) with updates for Mo, Na, and SO4 from Raisbeck et al. (2011). 2 Insufficient data for livestock; value for marine aquatic life is used. 3 Lead is accumulative, and problems may begin at a threshold value of 0.05 mg/L. 4 Insufficient data for livestock; value for human drinking water used. 5 Short-term exposure (days/weeks) can be up to 4000 mg/L, assuming normal feedstuff Na concentrations. 6 Short-term exposure (days/weeks) can be up to 1.8 mg/L, assuming normal feedstuff SO4 concentrations.

3.3 Impoundments

Uses of reclaimed water for maintenance of impoundments range from water hazards on golf courses to full-scale development of water-based recreational impoundments involving incidental contact 2012 Guidelines for Water Reuse

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3.3.1 Recreational and Landscape Impoundments One example of reclaimed water use for recreational impoundments is the Santee Lakes Recreation Preserve (Park), which is a recreational facility owned and operated by Padre Dam Municipal Water District. It is located strategically within San Diego County, Calif. Its seven lakes, which contain approximately 82 ac (33 ha) of water, were formed by sand and gravel mining in the dry stream bed of Sycamore Canyon as part of the district’s original water reclamation program. In the early 1960s, the district converted the lakes to recreational use to demonstrate the concept of water reuse. Its purpose was also to gain public acceptance of reclaimed water for recreational, agricultural, irrigation, and industrial applications. As with any form of reuse, the development of water reuse projects that include impoundments will be a function of water demand coupled with a cost-effective source of suitable quality reclaimed water. Regulation of impoundments that are maintained using reclaimed water typically is according to the potential for contact for that use. For example, in Arizona, reclaimed water that is used for recreational impoundments where boating or fishing is an intended use of the impoundment must meet Class A requirements, which includes secondary treatment, filtration, and disinfection so that no detectable fecal coliform organisms are present in four of the last seven daily reclaimed water samples taken, and no single sample maximum concentration of fecal coliform organisms exceeds 23/100 mL. Even though NPDES permits may allow discharge of treated effluent into a water body with higher bacterial concentrations, swimming and other full-body recreation activities are prohibited where reclaimed water is used to maintain the “recreational” impoundment. This is consistent with goals to protect public health, particularly in light of evidence provided by Wade et al. (2010) who have shown a relationship between gastrointestinal illness and estimates of fecal indicator organisms and that children less than 11 years old are at greater risk from exposure (Wade et al., 2008). In impoundments where body contact is prohibited, such as a manmade facility that is created for storage, landscaping, or for aesthetic purposes only, less stringent requirements may apply.

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3.3.2 Snowmaking The benefits of installing a reclaimed water distribution system to help meet peak irrigation demands during growing season has to be weighed carefully with the costs associated with managing the reclaimed water in the winter months when temperature and climate conditions render the system useless for irrigation. When water demands from customers that require consistent flow (such as industrial or cooling system customers) cannot be secured as part of a reclaimed water customer base in winter months, one option to manage reclaimed water in the winter months may be to make snow. While snowmaking is sometimes regulated as an urban reuse, some states consider snowmaking for recreational purposes to have body contact that requires water quality similar to that used in recreational impoundments, which is why this reuse application is discussed in this section. Making snow from reclaimed water for the purpose of prolonging and avoiding interruption of the recreation season of sledding and skiing areas is becoming more popular, particularly in water-scarce areas. However, given the difficulty of otherwise making use of reclaimed water during the winter months, it is hard to ignore the resource as a water supply for snowmaking. This is particularly the case in areas where the temperatures are low enough to maintain water in the form of snow but natural precipitation will not otherwise support a longer recreation season. In most states, use of reclaimed water for snowmaking is either regulated or managed as a winter-time disposal option or as a reuse option, but seldom both. Snowmaking with reclaimed water is being done in the United States, Canada, and Australia (e.g., Victoria’s Mount Buller Alpine Resort installed in 2008 and Mount Hotham Resort installed in 2009). Snowmaking using reclaimed water in the United States is occurring in Maine, Pennsylvania, and California. The details of these facilities are shown in a case study [US-MESnow]. Some states have rules or regulations pertaining to snowmaking with reclaimed water. There do not appear to be any human health effects studies associated with exposure to snow made with reclaimed water. The highlights of the regulations from a few select states are provided to exemplify how different states implement snowmaking with reclaimed water.

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Storing or stockpiling reclaimed water in the form of snow avoids the cost of building large surface water reservoirs or additional lagoon treatment modules. Depending on the quality of the originating reclaimed water, precautions may need to be taken regarding the fate of snowmelt. It may be necessary to prevent snowmelt from frozen reclaimed water with a relatively high content of phosphorus from entering a sensitive water body. Conversely, if reclaimed water can be sprayed onto a seasonally dormant agricultural field, the phosphorus may be a benefit to the farmer who will plant the field in the spring.

and no detectable fecal coliform organism in four of the last seven daily reclaimed water samples (single sample maximum of 23 fecal coliform organism per 100 mL). As of 2012, there were no ADEQ-permitted uses of reclaimed water for snowmaking in Arizona. However, the Sunrise Park Resort, owned and operated by the White Mountain Apache Tribe (WMAT), makes use of WWTP effluent blended with another source of water for snowmaking. ADEQ does not regulate the WMAT, as they are a sovereign nation; thus, it is not known what water quality is used, to what extent, or with what frequency.

Care must also be taken to quantify the volume of snowmelt runoff that will occur according to a range of spring thaw scenarios to manage the runoff. Planners should consider downstream and groundwater rights to the water diverted for snowmaking and to the 3 snowmelt. An ac-ft (1,200 m ) of medium-density snow (1 ac with 1 ft of snow on it) has an equivalent water 3 volume of approximately 146,000 gallons (550 m ). It is necessary to consider the density of the accumulated snow and its depth to avoid overfilling the reservoir with snowmelt. Note also that snow will sublimate (convert from the solid phase of water to the gaseous phase without going through the liquid phase) during storage.

A service agreement between the city of Flagstaff and owners of the Snowbowl Ski Resort allowed Flagstaff to sell reclaimed water for snowmaking. Planning started in 2000, and approval from the U.S. Forest Service was granted in 2004 (Snowbowl operates on federal land). In 2004, opponents to snowmaking with reclaimed water, led by the Navajo Nation, filed suit against Snowbowl and the city of Flagstaff. Following several court cases, in 2009 the full U.S. 9th Circuit Court refused to reject lower court decisions supporting the Snowbowl/Flagstaff agreement, and the U.S. Supreme Court refused to hear the case. In September 2009 a new suit was filed by Save the Peaks Coalition, and on February 9, 2012, a threejudge panel of the 9th U.S. Circuit Court of Appeals rejected the current suit as it was “virtually identical” to the previous suit (Associated Press, 2012).

Captured snowmelt from snow made from reclaimed water of a particular quality may not reflect the original water quality. Snowmelt may pick up contaminants from the soil, including microbiological and chemical constituents; further, sublimation has the effect of concentrating whatever constituents are present into higher concentrations. In addition, some constituents that were present in the original reclaimed water may degrade over time, or be “lost” (as in the case of nutrients) to the soil when the snow melts. Therefore, if snowmelt is to be introduced into the reclaimed water distribution system, it may be necessary to treat it to achieve the same level of quality as the reclaimed water produced by the reclamation facility.

Arizona The Arizona Department of Environmental Quality (ADEQ) regulates reclaimed water quality for prescribed uses allowing for snowmaking with Class A reclaimed water, which is wastewater that has undergone secondary treatment, filtration, and disinfection to achieve a 24-hour average turbidity of 2 NTU or less (instantaneous turbidity of 5 NTU or less)

2012 Guidelines for Water Reuse

California CDPH regulates recycled water use and allows for snowmaking with disinfected filtered reclaimed water meeting specific turbidity criteria. However, it is noted that in some cases (such as for the Donner Summit Public Utilities District), snowmaking may also be permitted under an NPDES permit.

Colorado The Colorado Department of Public Health and Environment’s Regulation No. 84—Reclaimed Water Control Regulation does not mention snowmaking. Regulators in Colorado view snowmaking with reclaimed water as inevitable discharge to surface waters during snowmelt and runoff. Therefore, use of reclaimed water to make snow would be permitted under the NPDES discharge framework rather than under Regulation No. 84. Further, because water rights regulations in Colorado limit the amount of water that can be reused to the volume imported from west

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of the Continental Divide, reclaimed water is first applied to highest use at lowest cost.

Maine The Maine Department of Environmental Protection (MDEP) does not have reclaimed water quality or water reuse rules, let alone regulations for snowmaking. However, the MDEP issues wastewater discharge permits for making snow with reclaimed water under the Maine Pollution Discharge Elimination System program. Snowmaking is used to reduce the volume of water in lagoons or to otherwise manage treatment plant effluent. There are currently systems in operation in three Maine communities (town of Rangeley; Carrabassett Valley Sanitary District, which serves Sugarloaf Mountain Ski Resort; and Mapleton Sewer District).

New Hampshire New Hampshire’s rules regarding snowmaking provide more discussion about snowmaking than any other state. Snow can be made using disinfected, filtered secondary effluent, depending on the end use of the manufactured snow. It can be used to recharge aquifers or for recreation purposes, such as skiing. Snow made from reclaimed water is referenced as “ESnow” (for Effluent Snow) in New Hampshire’s Land Treatment and Disposal of Reclaimed Wastewater: Guidance for Groundwater Discharge Permitting revised July 30, 2010. Before reclaimed water is considered for recreational snowmaking, it must first be filtered with site-specific nutrient removal depending on snowmelt and runoff to surface streams. Treatment beyond secondary quality is commonly achieved using a variety of biological nutrient removal technologies, and the processed wastewater is filtered using advanced (ultra) filtration to achieve 4-log reduction of viral pathogens; disinfection is also included as the final treatment process. It is noteworthy that higher quality reclaimed water is required for golf course irrigation than for snowmaking.

Pennsylvania Although the Pennsylvania Department of Environmental Protection does not have water reuse regulations, it does have guidelines that allow water reuse through the issuance of a Water Quality Management permit from the agency. The guidelines, titled Reuse of Treated Wastewater Guidance Manual

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362-0300-009 sets forth minimum treatment goals for snowmaking. Snowmaking is allowed with Class B water, which is water that has undergone secondary treatment, filtration, and disinfection. Where chlorine is utilized for disinfection, a total chlorine residual of at least 1.0 mg/L should be maintained for a minimum contact time of 30 minutes at design average flow, and there should be a detectable chlorine residual (>0.02 mg/L) at the point of reuse application. Where UV light is used for disinfection, a design dose 2 of 100 mJ/cm under maximum daily flow should be 2 used. The design dose may be reduced to 80 mJ/cm 2 for porous membrane filtration and 50 mJ/cm for semi-permeable membrane filtration. This dose should also be based on continuous monitoring of lamp intensity, UV transmittance, and flow rate. Reclaimed water is being used for snowmaking at Seven Springs Mountain Resort, and planning for use at Bear Creek Mountain Resort is underway.

3.4 Environmental Reuse Environmental reuse primarily includes the use of reclaimed water to support wetlands and to supplemental stream and river flows. Aquifer recharge also may be considered environmental reuse, but because this practice is integral to management of many reuse systems, an expanded discussion of this topic is provided in Section 2.3. A more detailed discussion of using wetlands and other natural systems for treatment to enhance water quality is provided in Chapter 6 with regulatory requirements for this reuse type described in Section 4.5.2.7.

3.4.1 Wetlands Over the past 200 years, substantial acreage of wetlands in the continental United States have been destroyed for such diverse uses as agriculture, mining, forestry, and urbanization. Wetlands provide many important functions, including flood attenuation, wildlife and waterfowl habitat, food chain support, aquifer recharge, and water quality enhancement. In addition, maintenance of wetlands in the landscape mosaic is important for regional hydrologic balance. Wetlands naturally provide water conservation by regulating the rate of evapotranspiration and, in some cases, by providing aquifer recharge. Wetlands are also natural systems that can be used to treat a wide range of pollution sources, and they are particularly attractive for rural areas in developed countries and for general use in developing countries.

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and the existing treatment plant was upgraded to an advanced biological treatment plant. This system, along with additional constructed wetlands, provides some aquifer infiltration, but the vast majority flows into two of CCWA’s water supply reservoirs—Shoal Creek and Blalock reservoirs. Water typically takes 2 years under normal conditions to filter through wetlands and reservoirs before being reused and takes less than a year under drought conditions. The Panhandle Road Constructed Wetlands and the E.L. Huie Constructed Wetlands have treatment capacities of 4.4 mgd (193 L/s) and 17.4 mgd (762 L/s), respectively. The transition from LAS to wetlands has saved energy costs through reduced pumping. The wetlands system is less expensive to maintain and operate and has allowed CCWA to reduce maintenance staff, equipment, and materials. The wetlands treatment system and indirect reuse program have lowered CCWA’s need for additional reservoir storage and water withdrawals.

Development has altered the landscape, including changing the timing and quantities of stormwater and surface water flows and lowering of the groundwater tables, which affect environmental systems that have adapted and depend on these for their existence. Reclaimed water could be used to mitigate some of these impacts. Application of reclaimed water serves to restore and enhance wetlands that have been hydrologically altered. New wetlands can be created through application of reclaimed water, resulting in a net gain in wetland acreage and function. In addition, constructed and restored wetlands can be designed and managed to maximize habitat diversity within the landscape. While the focus of this section is to highlight applications of wetlands, it is worth noting that some states, including Florida, South Dakota, and Washington, do provide regulations to specifically address use of reclaimed water in wetlands systems. In addition to state requirements, natural wetlands, which are considered waters of the United States, are protected under EPA’s NPDES Permit and Water Quality Standards programs. The quality of reclaimed water entering natural wetlands is regulated by federal, state, and local agencies and must be treated to secondary treatment levels or greater. On the other hand, constructed wetlands, which are built and operated for the purpose of treatment, are not considered waters of the United States. Several case studies focused on wetlands are highlighted in this document and briefly summarized below: 

US-AZ-Phoenix: The 91st Avenue WWTP reuses approximately 60 percent of the current plant production (by a nuclear generating station for cooling tower makeup water, new constructed wetlands, and an irrigation company for agricultural reuse), with the remaining effluent discharged to the dry Salt River riverbed that bisects the nearby communities.



US-GA-Clayton County: The Clayton County Water Authority (CCWA) began water reuse in the 1970s when a land application system (LAS) was selected as a way to increase water supplies for its growing population while minimizing the stream impact of wastewater discharges. Over the past decade, the LAS was converted into a series of treatment wetlands,

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US-FL-Orlando Wetlands: The Orlando Easterly Wetlands enhances the environment with highly-treated reclaimed water. The project began in the mid-1980s when the city, faced with the need to expand its permitted treatment capacity, was unable to increase the amount of nutrients being discharged into sensitive area waterways. The constituents of concern in the effluent consist primarily of nitrogen and phosphorus, which can promote algae blooms that deplete oxygen in a water body and result in fish kills and other undesirable conditions. Florida water bodies are particularly susceptible to these problems due to periods of very low flows that occur in the summer. This project has seen great success throughout its two decades of performance. The Orlando Wetlands Park consists of 1,650 ac (670 ha) of hardwood hammocks, marshes, and lakes, and is a great location for bird-watching, nature photography, jogging, and bicycling.



Israel-Vertical Wetlands: Compact verticalflow constructed wetlands are being used in Israel for decentralized treatment of domestic wastewater. When treated with the UV disinfection unit, the effluent of the recirculating

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vertical flow constructed wetland (RVFCW) consistently met the stringent Israeli E. coli standards for reclaimed water irrigation of less than 10 cfu/100 mL (Inbar, 2007). The treated wastewater will be used for unrestricted landscape and, possibly, fodder irrigation.

3.4.1.1 Wildlife Habitat and Fisheries Diverse species of mammals, plants, insects, amphibians, reptiles, birds, and fish rely on wetlands for food, habitat, and/or shelter. Wetlands are some of the most biologically productive natural ecosystems in the world, comparable to tropical rain forests or coral reefs in the number and variety of species they support. Migrating waterfowl rely on wetlands for resting, eating, and breeding, leading to increased populations. Wetlands are also vital to fish health and, thus, to the multibillion dollar fishing industry in the United States. Wetlands also provide an essential link in the life cycle of 75 percent of the commerciallyharvested fish and shellfish in the United States, and up to 90 percent of the recreational fish catch. Wetlands provide a consistent food supply, shelter, and nursery grounds for both marine and freshwater species. The city of Sequim, Wash., constructed its water reclamation facility and upland reuse system to protect shellfish beds and conserve freshwater supplies. Due to the location of Sequim, it was vital for the community to make conservation and marine protection a priority [US-WA-Sequim]. Another case study, the Sierra Vista EOP, Ariz. [USAZ-Sierra Vista] spans 640 ac (260 ha) and includes 30 open basins that recharge nearly 2,000 ac-ft/yr (2.5 MCM/yr) of reclaimed water to the aquifer, 50 ac (20 ha) of constructed wetlands, nearly 200 ac of native 2 2 grasslands, and 1,800 ft (170 m ) of wildlife viewing facility. The constructed wetlands provide numerous beneficial services, including filtering and improving water quality as plants take up available nutrients. In the EOP wetlands, secondary treated effluent is filtered naturally. The primary purpose of EOP is to offset the effects of continued groundwater pumping that negatively impacts the river and to protect the habitat for native and endangered species.

3.4.1.2 Flood Attenuation and Hydrologic Balance Flood damages in the United States average $2 billion each year, causing significant loss of life and property (EPA, 2006a). One of the most valuable benefits of

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wetlands is their ability to store flood waters; maintaining only 15 percent of the land area of a watershed in wetlands can reduce flooding peaks by as much as 60 percent. In addition to reducing the frequency and intensity of floods by acting as natural buffers that soak up and store a significant amount of flood water, coastal wetlands serve as storm-surge protectors when hurricanes or tropical storms come ashore. And, according to Hey et al. (2004), the damage sustained by the Gulf Coast during Hurricane Katrina could have been less severe if more wetlands had been in place along the coast and Mississippi delta. As a result, with the encouragement of the Louisiana Department of Environmental Quality and a $400,000 grant from the Delta Regional Authority, the Sewerage and Water Board of New Orleans identified a plan to use highly-treated reclaimed water from the WWTP to restore the damaged marsh lands. The multi-disciplinary project also includes proof of a new technology, ferrate (discussed further in Chapter 6), that is intended to scrub treated effluent of emerging pollutants of concern and set new standards for use of biosolids in wetlands assimilation (AWWA, 2010).

3.4.1.3 Recreation and Educational Benefits Wetlands such as the Orlando Wetlands Park [US-FLOrlando Wetlands] are also inviting places for popular recreational activities, including hiking, fishing, birdwatching, photography, and hunting. In addition to the many ways wetlands provide recreational benefits, they also offer numerous less-tangible benefits. These include providing aesthetic value to residential communities, reducing streambank erosion, and providing educational opportunities as an ideal “outdoor classroom,” as demonstrated at the Sidwell Friends School case study [US-DC-Sidwell Friends]. The school, in Washington, D.C., incorporated a constructed wetland into its middle school building renovation. This water reuse system was part of an overall transformation of a 50-year-old facility into an exterior and interior teaching landscape that seeks to foster an ethic of social and environmental responsibility in each student. With a focus on smart water management, a central courtyard was developed with a rain garden, pond, and constructed wetland that uses stormwater and wastewater for both ecological and educational purposes. More than 50 plant species, all native to the Chesapeake Bay region, were included in the landscape.

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3.4.2 River or Stream Flow Augmentation Among the numerous water industry challenges are high demand and inadequate supplies. Water conservation and reuse can reduce the demand on aquifers, as can river or stream flow augmentation. River and stream augmentation differs from a surface water discharge in several ways. Augmentation seeks to accomplish a benefit, such as aesthetic purposes or enhancement of aquatic or riparian habitat, whereas discharge is primarily for disposal. River or stream flow augmentation may provide an economical method of ensuring water quality, as well as having other benefits. It can minimize the challenge of locating a reservoir site, the additional water can improve the overall water quality of the receiving water body, and it can ameliorate the effect of low flow drought conditions, providing high quality water at the time of test need. River and stream augmentation may also reduce or eliminate water quality impairment and may be desirable to maintain stream flows and to enhance the aquatic and wildlife habitat, as well as to maintain the aesthetic value of the water courses. This may be necessary in locations where a significant volume of water is drawn for potable or other uses, largely reducing the downstream volume of water in the river or stream. As with impoundments, water quality requirements for river or stream augmentation will be based on the designated use of the water course and the aim to enhance an acceptable appearance. In addition, there should be an emphasis on creating a product that can promote native aquatic life. The quality of the reclaimed water discharged to the receiving water body is critical to evaluating its benefits to the stream. Currently, there are limited data available to assess such water augmentation schemes a priori, and detailed, site-specific evaluations are needed (WRRF, 2011a). Water reclamation for stream augmentation applications requires consideration of a complex set of benefits and risks. For example, wastewater is known to contain microbiological contaminants as well as other trace levels of organic contaminants, some of which may be carcinogens, toxins, or endocrine disruptors (Lazorchak and Smith, 2004). These contaminants may be present in the reclaimed water at varying concentrations, depending upon the treatment process used (Barber et al., 2012), and the presence of these types of compounds in a receiving water body may have ecotoxicological consequences.

2012 Guidelines for Water Reuse

While some states have guidelines or regulations that provide requirements for reclaimed water quality and monitoring to protect wetlands (Section 4.5.2.7), which may even be considered part of the treatment system, requirements for reclaimed water quality for augmenting rivers or streams are often covered under a discharge permit. And, while the whole effluent toxicity (WET) testing and biomonitoring required in some NPDES permits may provide an indication of the overall ecological effect of the reclaimed water, this approach still presents a regulatory challenge because the current science on compounds of emerging concern is not fully defined (Section 6.2.2.3). Thus, evaluation and design for river or stream flow augmentation must address the site-specific water quality and habitat needs of the water course and any downstream use of the reclaimed water. And, in an appropriately designed river or stream augmentation project where treatment is provided to be protective of the end use of the receiving water, there are opportunities for public education regarding the value of reclaimed water as a resource and its potential to provide environmental benefits. One case study example illustrates the potential for positive impacts of water reuse on downstream ecosystems. In the city of Sequim, Wash., in addition to municipal uses, reaerated reclaimed water is discharged into Bell Creek to improve stream flows for fisheries and habitat restoration, keeping the benthic layer wet for small species that live in the streambed [US-WA-Sequim].

3.4.3 Ecological Impacts of Environmental Reuse The NRC report describes how ecological risks in environmental reuse applications should be assessed relative to existing wastewater discharge practices (NRC, 2012). The report concludes that the ecological risks in reuse projects for ecological enhancement are not expected to exceed those encountered with the normal surface water discharge of reclaimed water, although risks from reuse could be lower if additional levels of treatment are applied. The report cautions that current limited knowledge about the ecological effects of trace chemical constituents requires research to link population level effects in natural aquatic systems to initial concerning laboratory observations. In reuse applications targeted for ecological enhancement of sensitive aquatic systems, careful assessment of risks from these constituents is

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warranted, because aquatic organisms can be more sensitive to certain constituents than humans (NRC, 2012). Lake Elsinore, southern California’s largest natural lake, is fed only by rain and natural runoff, with an annual evaporation rate of 4.5 ft. Because of these characteristics, the lake has been plagued for decades by low water levels and high concentrations of nutrients. The Elsinore Valley Municipal Water District (EVMWD) implemented a project to transfer 5 million gallons of reclaimed water per day to the lake to help with the low water levels [US-CA-Elsinore Valley].

3.5 Industrial Reuse

Traditionally, pulp and paper facilities, textile facilities, and other facilities using reclaimed water for cooling tower purposes, have been the primary industrial users of reclaimed water. Since the publication of the 2004 Guidelines for Water Reuse, the industrial use of reclaimed water has grown in a variety of industries ranging from electronics to food processing, as well as a broader adoption by the power-generation industry. Over the past few years, these industries have embraced the use of reclaimed water for purposes ranging from process water, boiler feed water, and cooling tower use to flushing toilets and site irrigation. Additionally, industries and commercial establishments seeking LEED certification are driven to reclaimed water to enhance their green profile. In addition, these facilities recognize that reclaimed water is a resource that can replace more expensive potable water with no degradation in performance for the intended uses. When reclaimed water was first used for industrial purposes (dating back to the first pulp and paper industries), it was generally treated and reused on-site. As water resources in the arid states have become increasingly stressed (Arizona, California, and Texas) and availability of groundwater sources are becoming extremely limited (Florida), municipal facilities have started to produce reclaimed water for irrigation, industrial, and power company users. This section examines water reuse in traditional industrial settings (cooling towers and boiler water feed) and discusses emerging industries, such as electronics and produced waters from natural gas operations. Additional discussion on state guidelines and regulations for industrial reuse is provided in Section 4.5.2.8.

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Case study examples of industrial water reuse to address energy and sustainability goals include reuse projects by companies such as Coca-Cola, Frito-Lay, and Intel [US-AZ-Frito Lay]. Coca-Cola has installed recycle-and-reclaim loops in 12 of its water treatment systems in North America and Europe, with goals of equipping up to 30 facilities with these systems by the end of 2012. These loops allow facilities to reuse processed water in cooling towers, boilers, or cleaning, saving an average of 57 million gallons (220 million liters) of water per system annually.

3.5.1 Cooling Towers Cooling towers are recirculating evaporative cooling systems that use the reclaimed water to absorb process heat and then transfer the heat by evaporation. As the cooling water is recirculated, makeup water (reclaimed water) is required to replace water lost though evaporation. Water must also be periodically removed from the cooling water system to prevent a buildup of dissolved solids in the cooling water. There are two common types of evaporative cooling water systems—cooling towers and spray ponds. Spray ponds are not widely used and generally do not utilize reclaimed water. Cooling towers have become very efficient, with only 1.5 to 1.75 percent of the recirculated water being evaporated for every 10°F (6°C) drop in process water temperature, reducing the need to supplement the system flow with makeup water. Because water is evaporated, dissolved solids and minerals remain in the recirculated water, and these solids must be removed or treated to prevent accumulation on equipment. Removal of these solids is accomplished by discharging a portion of the cooling water, referred to as blow-down water, which is usually treated by a chemical process and/or a filtration/ softening/clarification process before disposal to a local WWTP. Cooling tower designs vary widely. Large hyperbolic concrete structures can range from 250 to 400 ft (76 to 122 m) tall and 150 to 200 ft (46 to 61 m) in diameter and are common at utility power plants, as shown in Figure 3-5. These cooling towers can recirculate (cool) approximately 200,000 to 500,000 gpm (12,600 to 31,500 L/s) and evaporate approximately 6,000 to 15,000 gpm (380 to 950 L/s) of water. Smaller cooling towers, which may be used at a variety of industries, can be rectangular boxes constructed of wood, concrete, plastic, and/or fiberglass-reinforced plastic with circular fan housings for each cell. Each cell can

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Figure 3-5 Large hyperbolic cooling towers (Photo Courtesy of International Cooling Towers)

recirculate (cool) approximately 3,000 to 5,000 gpm (190 to 315 L/s). Commercial air conditioning cooling tower systems can recirculate as little as 100 gpm (6 L/s) to as much as 40,000 gpm (2,500 L/s). Any contamination of the cooling water through process in-leakage, atmospheric deposition, or treatment chemicals will also impact the water quality. While reclaimed water generally has very low concentrations of microorganisms due to the high level of treatment, one of the major issues with reclaimed water use in cooling towers relates to occurrence of biological growth when nutrients are present. Biological growth can produce undesirable biofilm deposits, which can interfere with heat transfer and cause microbiologically-induced corrosion from acid or corrosive by-products and may shield metal surfaces from water treatment corrosion inhibitors and establish under-deposit corrosion. Biological films can grow rapidly and plug heat exchangers, create film on the cooling tower media, or plug cooling tower water distribution nozzles/sprays.

form scale in concentrated cooling water generally include calcium phosphate (most common), silica (fairly common), and calcium sulfate (fairly common); other minerals that are less commonly found include calcium carbonate, calcium fluoride, and magnesium silicate. Constituents with the potential to form scale must be evaluated and controlled by chemical treatment and/or by adjusting the cycles of concentration. Therefore, reclaimed water quality must be evaluated, along with the scaling potential to establish the use of specific scale inhibitors, as demonstrated by the Southwest Florida Water Management District through its Regional Reclaimed Water Partnership Initiative [US-FL-SWFWMD Partnership] illustrating the use of reclaimed water for cooling water at a major utility in Florida. Another power plant, located in Colorado, [US-CO-Denver Energy] utilizes reclaimed water for cooling towers.

Scaling can also be a problem in cooling towers. The primary constituents resulting in scale potential from reclaimed water are calcium, magnesium, sulfate, alkalinity, phosphate, silica, and fluoride. Minerals that

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3.5.2 Boiler Water Makeup The use of reclaimed water for boiler make-up water differs little from the use of conventional potable water—both require extensive pretreatment. Water quality requirements for boiler make-up water depend on the pressure at which the boiler is operated; in general, higher pressures require higher-quality water. The primary concern is scale buildup and corrosion of equipment. Control or removal of hardness from either potable water or reclaimed water is required for use as boiler make-up; additionally, control of insoluble scales of calcium and magnesium, and control of silica and alumina, are also required. Alkalinity of the reclaimed water, as determined by its bicarbonate, carbonate, and hydroxyl content, is also of concern because excessive alkalinity concentrations in boiler feed water may contribute to foaming and other forms of carryover, resulting in deposits in superheater, reheater, and turbine units. Bicarbonate alkalinity in feed water breaks down under the influence of boiler heat to release carbon dioxide, a major source of

localized corrosion in steam-using equipment and condensate-return systems. Organics in reclaimed water can also cause foaming in boilers, which can be controlled by carbon adsorption or ion exchange. The American Boiler Manufacturers Association (ABMA) maximum recommended concentration limits for water quality parameters for boiler operations is presented in Table 3-8. For steam generation, TDS levels are recommended to be less than 0.2 part per million (ppm) and less than 0.05 ppm for once through steam generation (OTSG). Since 2000, several refineries in southern Los Angeles, Calif., have turned to using recycled water as their primary source of boiler make-up water. Using clarification, filtration, and RO, high-quality boiler make-up water is produced that provides water supply, chemical, and energy savings. The West Basin Municipal Water District (WBMWD) supplies recycled water for both low-pressure and high- pressure boiler feed water; because high-quality water is required for high-pressure boiler feed, some of the water (after the

Table 3-8 Recommended boiler water limits Drum Operating 90110011501Pressure (psig) 0-300 301-450 451-600 601-750 751-900 1000 1500 2000 OTSG Steam TDS max 0.2-1.0 0.2-1.0 0.2-1.0 0.1-0.5 0.1-0.5 0.1-0.5 0.1 0.1 0.05 (ppm) Boiler Water TDS max 600500200700-3500 150-750 125-625 100 50 0.05 (ppm) 3000 2500 1000 Alkalinity max (ppm) 350 300 250 200 150 100 n/a n/a n/a TSS Max (ppm) 15 10 8 3 2 1 1 n/a n/a Conductivity max 11009008003002002000.15150 80 (µmho/cm) 5400 4600 3800 1500 1200 1000 0.25 Silica max (ppm SiO2) 150 90 40 30 20 8 2 1 0.02 Feed Water (Condensate and Makeup, After Deaerator) Dissolved Oxygen 0.007 0.007 0.007 0.007 0.007 0.007 0.007 0.007 n/a (ppm O2) Total Iron 0.1 0.05 0.03 0.025 0.02 0.02 0.01 0.01 0.01 (ppm Fe) Total Copper (ppm Cu) 0.05 0.025 0.02 0.02 0.015 0.01 0.01 0.01 0.002 Total Hardness 0.3 0.3 0.2 0.2 0.1 0.05 ND ND ND (ppm CaCO3) pH @ 25º C 8.3-10.0 8.3-10.0 8.3-10.0 8.3-10.0 8.3-10.0 8.8-9.6 8.8-9.6 8.8-9.6 n/a Nonvolatile TOC 1 1 0.5 0.5 0.5 0.2 0.2 0.2 ND (ppm C) Oily Matter 1 1 0.5 0.5 0.5 0.2 0.2 0.2 ND (ppm) Source: Boiler Water Quality Requirements and Associated Steam Quality for Industrial/Commercial and Institutional Boilers (American Boiler Manufacturers Association, 2005)

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first-pass RO treatment and disinfection) passes through RO a second time (second pass) to remove additional dissolved solids from the water. For water fed to the Chevron refinery in El Segundo, Calif., about 5.8 mgd (254.1 L/s) receives single-pass RO treatment low-pressure boiler feed, while an additional 2.4 mgd (105 L/s) receives second-pass RO treatment for highpressure boiler feed. The product water is pumped to a storage tank at the nearby Chevron refinery. Boiler water is also produced at the WBMWD’s satellite MF/RO plant in Torrance, Calif.; the 2,200 gpm (3,500 ac-ft/yr or 4.3 MCM/yr) satellite treatment plant located on-site at the Exxon Mobil refinery produces water for their boiler feed operations. Another WBMWD facility in Carson also provides recycled water to the BP refinery.

3.5.3 Produced Water from Oil and Natural Gas Production While not specifically reuse of treated municipal effluent, the reuse of produced water that is generated as a by-product resulting from the extraction of crude oil or natural gas from the subsurface warrants discussion. Produced water, for the purposes of this discussion, is defined as any water present in a reservoir with a hydrocarbon resource that is produced to the surface with the crude oil or natural gas. There are three types of water associated with subsurface hydrocarbon reservoirs and production operations: 

Formation water is water that flows from the hydrocarbon zone or from production activities when injected fluids and additives are introduced to the formation.



Produced water is generated when the hydrocarbon reservoir is produced and formation water is brought to the surface.



Flowback is water that returns to the surface within a few days or weeks following hydraulic fracturing performed on a natural hydrocarbon reservoir; this practice involves injection of large volumes of fracturing fluid into the hydrocarbon reservoir.

Recent advances in drilling techniques have led to an increase in production water from unconventional gas formations, including coal seams, tight sand, and shale deposits. These new techniques result in approximately eight barrels of water brought to the surface for every barrel of oil. This produced water is often highly saline and contaminated by hydrocarbons; it is a waste that requires treatment, disposal, and, potentially, recycling. Handling this produced water is an integral part of the oil and gas industry, and according to estimates by Clark and Veil (2009), the United States generates around 20.7 bbl/yr out of a worldwide total 69.8 bbl/yr (or 2.4 mgd of 8 mgd total; 9 ML/d of 30 ML/d total). The breakdown by state of produced water is shown in Figure 3-6. As might be expected, the quality of produced waters varies widely, ranging from water that meets state and federal drinking water standards to water having very high TDS concentrations. The properties can vary considerably depending on geographic location, the source geological formation, and the type of hydrocarbon being extracted. When produced water contains certain constituents at high concentrations, it can threaten aquatic life if discharged to streams or other water bodies or used as irrigation water without treatment. As a result, produced water management is subject to applicable federal and state regulatory requirements, which are further described by the U.S. Department of Energy in an online resource, The Produced Water Management System (DOE, n.d.).

69.8 billion bbl/yr Worldwide produced water volume

Other States 20%

Louisiana 5% Kansas 6%

Texas 35%

20.7 billion bbl/yr U.S. produced water volume (2007)

Oklahoma 11% Wyoming 11%

California 12%

Figure 3-6 Estimates of produced water by state (GWI, 2011)

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It is of interest to note that under current regulations, produced water can only be utilized west of the 99 meridian and the practice is most contentious. Where produced water can be used, as with reclaimed water produced from treated municipal effluent, there are a variety of uses depending on the produced water quality and the level of treatment provided. Low TDS water sources, such as those common with coalbed methane production, may be reused with very little treatment (NRC, 2010). Higher TDS sources usually require a much higher level of treatment and may be limited in their end uses. End uses of treated, produced water include surface water flow augmentation, aquifer recharge, storage and recovery, crop irrigation, and livestock watering. Produced water may also be used for a variety of industrial purposes, especially in areas where freshwater resources are scarce. It is important to note that produced waters associated with hydraulic fracturing operations cannot be used as reclaimed water for alternative uses without extensive and expensive treatment operations, and reuse is limited to development of additional wells, with appropriate treatment. Treatment of produced water is often required before the water can be put to beneficial reuse. The degree of treatment and the type of treatment technology used is based on a number of factors, including the produced water quality, volume, treated water quality objectives, options available for disposal of residual waste (such as concentrated brine), and cost. In oil and gas operations, it is sometimes necessary to use modular technologies that can be mobilized for localized treatment in the field versus building a fixed-based treatment facility in a central location. The overall objective is to develop a simple, cost-effective treatment solution capable of consistently meeting effluent treatment objectives. Because of the wide variation in produced water quality and treatment objectives in oil and gas fields across the United States, development of the best solution is challenging and often requires a combination of treatment technologies to meet the individual needs of each operator. Treatment technologies commonly used for produced water prior to reuse include oil-water separators, dissolved gas flotation or coalescing media separators, adsorption, and filtration targeted for removal of specific constituents from the produced water. As a result, the best approach must balance produced water quality, simplicity of operations, treatment objectives, and cost.

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3.5.4 High-Technology Water Reuse The use of reclaimed water in high-technology manufacturing, such as the semiconductor industry, is a relatively new practice. Within the semiconductor industry, there are two major processes that use water: microchip manufacturing, which has rarely utilized reclaimed water, and the manufacture of circuit boards. In circuit board manufacturing, water is used primarily for rinse operations; similar to production of boiler feed water, reclaimed water for circuit board manufacturing requires extensive treatment. While only circuit board manufacturing uses reclaimed water in the actual production process, both semiconductor and circuit board manufacturing facilities do use reclaimed water for cooling water and site irrigation. Examples of reuse in high-technology industries include projects by companies such as Intel, that improved the efficiency of the process used to create the ultra-pure water (UPW) required to clean silicon wafers during fabrication. Previously, almost 2 gallons of water were needed to make 1 gallon of UPW. Today, Intel generates 1 gallon of UPW from between 1.25 and 1.5 gallons. After using UPW to clean wafers, the water is suitable for industrial purposes, irrigation, and many other needs. Intel’s factories are equipped with complex rinse-water collection systems with separate drains for collecting lightly contaminated wastewater for reuse. This reuse strategy enables Intel to harvest as much water from its manufacturing processes as possible and then direct it to equipment such as cooling towers and scrubbers. In addition, several of Intel’s locations take back graywater from local municipal water treatment operations for municipal use. In 2010, Intel internally recycled approximately 2 billion gallons (7.6 MCM) of water, equivalent to 25 percent of its total water withdrawals for the year.

3.5.5 Prepared Food Manufacturing The food and beverage manufacturing industry was initially reluctant to use—and publicize the use of— reclaimed water because of public perception concerns. As knowledge of water reuse principles has increased, so has the reuse of highly-treated process waters that meet water quality criteria and address public health concerns. In many cases, not only is reuse of water at a manufacturing site “green,” but it also can reduce operating costs and an industry’s water footprint and, in some cases, provide better water quality than the public water supply.

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Because of the interest in reuse for the food and beverage industry, the International Life Sciences Institute Research Foundation (ILSIRF) was requested to develop guidelines for water recovery for multiple uses in beverage production facilities. Many beverage producers and food processors are experiencing multiple pressures to find ways to minimize the total volume of water they use in the production of product. Producers need to secure adequate, predictable, and sustainable supplies of water for all uses at reasonable costs, and with efficient usage to maximize product output. Reducing the “water footprint” of a facility that is feeling these pressures allows for greater production of product and less waste, as well as realizing possible economic advantages, and possibly better relations with local citizens and governments. Companies such as Coca-Cola and PepsiCo are implementing practices to improve their water use in their operations as further described in case study examples of water recovery practices at beverage processing facilities [US-GACoca-Cola and US-NY-PepsiCo]. In response to this request, ILSIRF convened an international expert committee to carry out the guideline development process that has been underway since the summer of 2011; the expected completion and release date is the end of 2012. Beverage production processes covered by these guidelines include sodas, beer, juices, milk, and still or carbonated waters. The technologies being considered are typically used in current bottling or public drinking water and applicable water reclamation (ILSIRF, 2012). An award-winning example of integrated water reuse and sustainable practices is represented in the 2011 WateReuse Association Project of the Year award to PepsiCo/Frito-Lay Corporation Casa Grande, Ariz., facility [US-AZ-Frito Lay]. A new process water recovery treatment plant eliminated the previous land application system and currently recycles 75 percent of plant process water, saving 100 million gallons of water per year. Elimination of the land application site allowed for the installation of 5 MW of solar photovoltaic and Sterling dish technology, reducing impact on the local power grid. There are numerous water-demanding processes in the food and beverage industry, in addition to the potable water that may be incorporated into the product. These include cleaning and sanitation, steam

2012 Guidelines for Water Reuse

and hot water generation for processing, transport and cleaning of food products, equipment cleaning, container (bottles, cans, cartons, etc.) cleaning, can and bottle conveyor belt lubrication, can and bottle warming, and cooling. Water use for cleaning varies by industry segment from 22 percent of water use in jam production to 70 percent in the bakery segment (East Bay Municipal Utility Division, 2008). The transport of some food products, such as potatoes and other canned goods, through the processing facility may be accomplished via water flumes. While conveyor systems with water sprays or counter-flow wash systems are gaining in use as a water conservation measure, flume water and spray water from these processes are often collected and reused following filtration and disinfection, if appropriate. Conserving water through the use of dry cleaning methods is often integrated with other water reuse practices such as using internally recycled water from equipment cleaning for other uses or for irrigation. These practices can reduce operating costs and flows to the wastewater treatment process. Container cleaning (bottles, cans, kettles, other containers) is performed both before and after the filling process, as some overfill or spillage typically occurs. Wash water can be filtered through nanofiltration to recover both the sugars and product for use as animal feed or for growing yeast, while the cleaned water is available for additional reuse, such as crate or pallet cleaning or conveyor lubrication. Water, including reclaimed water, can be used for both heating and cooling, with water as the heat transfer medium. In canning, heating of cold ingredients after can filling prevents formation of condensation on the can and allows shorter drying cycles. The Coca-Cola Company has developed and is implementing its Rainmaker® beverage process water recovery system for clean-in-place and bottle washing. Following conventional treatment, the recovered water is further treated using MBR ultrafiltration, RO, ozonation, and UV disinfection. This process was bench tested then implemented in facilities in Ahmedabad, India, and Hermosillo, Mexico, with reduction in water use up to 35 percent. Based on the full-scale application, the Hermosillo facility has approval to continue use of the Rainmaker® system, and approval is anticipated in 2012 for Ahmedabad (Gadson et al., 2012).

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Reuse and waste load reduction combined in a new facility in Spartanburg, S.C., with expansion of New United Resource Recovery Corporation, LLC. (NURRC), a joint venture formed in 2007 between Coca-Cola Company and United Resource Recovery Corporation (URRC). NURRC recycles discarded plastic beverage bottles and other food product containers into NSF-certified reclaimed plastic for the bottling and beverage industry. When proposing a tenfold expansion of its facility, NURRC realized that this would also increase the wastewater load to the Spartanburg Sanitary Sewer District (SSSD), with a population equivalent load of 30,000 people and concurrent increase in water use. A high-strength treatment process relying on ultrafiltration and RO was installed to produce reclaimed water with BOD less than 1 mg/L and TDS less than 100 mg/L; the reclaimed water is now used in multiple nonpotable processes throughout the facility. On-site pretreatment of waste streams from the UF/RO process has resulted in a reduction of the waste load to SSSD to only 20 percent of the pre-expansion loads (Cooper et al., 2011).

3.6 Groundwater Recharge – Nonpotable Reuse

Groundwater recharge to aquifers not used for potable water has been practiced for many years, but has often been viewed as a disposal method for treated wastewater effluent. In addition to providing a method of treated effluent disposal, groundwater recharge of reclaimed water can provide a number of other benefits including 

Recovery of treated water for subsequent reuse or discharge



Recharge of adjacent surface streams



Seasonal storage of treated water beneath the site with seasonal recovery for agriculture

In many cases, groundwater can be recharged in a manner that also utilizes the soil or aquifer system where reclaimed water is applied as an additional treatment step to improve the reclaimed water quality. SAT, further discussed in Chapter 2, is particularly attractive in dry areas in arid regions and studies in Arizona, California, and Israel (Idelovich, 1981) have demonstrated that the recovery of the treated water may be suitable for unrestricted irrigation on many types of crops. Additional discussion on groundwater 3-26

recharge using land treatment and SAT are provided in the 2006 Process Design Manual - Land Treatment of Municipal Wastewater Effluents (EPA, 2006b) and Chapter 2 of this document. The Talking Water Gardens project in Oregon is a case study example of a public-private partnership that has helped Albany and Millersburg meet the newly established temperature total maximum daily limits (TMDL) for the Willamette River along with providing ecological services including groundwater recharge. The objective of the TMDL is to enhance the fish passage through that area, protecting a threatened salmonid species. The Talking Water Gardens serve as the final treatment step for wastewater effluent through natural hydrological processes in the wetlands. The project includes 37 ac (15 ha) of constructed wetlands that serve as an environmentally beneficial alternative to more traditional wastewater treatment methods. Project developers estimate that the wetlands treatment alternative will provide approximately 2.5 times more value in ecological services than a conventional treatment alternative when project attributes such as habitat disturbance, groundwater recharge, and habitat diversity are considered (EPA, n.d.).

3.7 Potable Reuse

In 1980, EPA sponsored a workshop on “Protocol Development: Criteria and Standards for Potable Reuse and Feasible Alternatives” (EPA, 1982). In the Executive Summary of that document, the chairman of the planning committee noted that “A repeated thesis for the last 10 to 20 years has been that advanced wastewater treatment provides a water of such high quality that it should not be discharged but put to further use. This thesis when joined to increasing problems of water shortage, provides a realistic atmosphere for considering the reuse of wastewater. However, at this time, there is no way to determine the acceptability of renovated wastewater for potable purposes.” This demonstrates that more than 30 years ago there was recognition of the importance of reuse for potable purposes as well as acknowledgement that what was known about the quality of the treated wastewater was a limitation to this practice. Since that time, a great deal has changed with respect to our understanding of this concept. The 2012 NRC report presents a brief summary of the nation’s recent history in water use and shows that although reuse is

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not a panacea, the amount of wastewater discharged to the environment is of such quantity that it could play a significant role in the overall water resource picture and complement other strategies, such as water conservation (NRC, 2012). One of the most important themes throughout the report is water reuse for potable reuse applications, including a discussion of both DPR and IPR and unplanned or de facto reuse. Water reclamation for nonpotable applications is well established, as discussed in the previous sections of this chapter, with system designs and treatment technologies that are generally well accepted by communities, practitioners, and regulatory authorities. The use of reclaimed water to augment potable water supplies has significant potential for helping to meet future needs, but planned potable water reuse only accounts for a small fraction of the volume of water currently being reused. However, if de facto (or unplanned) water reuse is considered, potable reuse is certainly significant to the nation’s current water supply portfolio. The unplanned reuse of wastewater effluent as a water supply is common, with some drinking water treatment plants using waters from which a large fraction originated as wastewater effluent from upstream communities, especially under low-flow conditions. Thus, the term de facto reuse will be used to describe unplanned IPR, which has been identified in the NRC report (2012), and is becoming recognized by professionals and the general public. Examples of de facto potable reuse abound, including such large cities as Philadelphia, Nashville, Cincinnati, and New Orleans, which draw their drinking water from the Delaware, Cumberland, Ohio, and Mississippi Rivers, respectively. These communities, and most others using unplanned IPR sources, do provide their customers with potable water from these rivers that meet current drinking water regulations by virtue of the drinking water treatment technologies used. This practice of discharging treated wastewater effluent to a natural environmental buffer, such as a stream or aquifer, has historically been deemed as an appropriate practice for IPR. However, research during the past decade on the performance of several fullscale advanced water treatment operations indicates

2012 Guidelines for Water Reuse

that some engineered systems can perform equally well or better than some existing environmental buffers in attenuating contaminants, and the proper use of indicators and surrogates in the design of reuse systems offers the potential to address many concerns regarding quality assurance. A number of these planned IPR projects have been in use for many years, demonstrating successful operation and treatment. Several examples of IPR and DPR projects are summarized in Table 3-9 to illustrate that this practice occurs worldwide at both very small and very large scales. And there are countless other planned IPR applications, where treated wastewater is deliberately recharged to a groundwater aquifer using rapid infiltration basins or injection wells, or to a drinking water reservoir. Additional information for the examples described in Table 3-9 are provided in case studies; in addition to the case studies provided in the table, more information on specific IPR projects in the United States is available in case studies for successful IPR projects [US-CA-Los Angeles County, US-CA-San Diego, US-AZ-Prescott Valley, US-CAVander Lans]. Implementation of technologies for increasingly higher levels of treatment for many of these IPR projects has led to questions about why reclaimed water would be treated to produce water with higher quality than drinking water standards, and then discharged to an aquifer or lake. This realization has led to new interest in DPR, utilizing the various multiple-barrier treatment technologies. However, even with the numerous successful IPR projects, such as cited in Table 3-9, and technology advances, Windhoek, Namibia, was the first city to implement long-term DPR without use of an environmental buffer. This is an example of the distinction between IPR and DPR: a reuse practice in which purified municipal wastewater is introduced into a water treatment plant intake (after treatment to at least near drinking water quality) for the purposes of this document, or directly into the water distribution system after meeting drinking water standards which has been proposed by others (Tchobanoglous et al., 2011).

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Table 3-9 Overview of selected planned indirect and direct potable reuse installations worldwide (not intended to be a complete survey) Country

City

Project Capacity (mgd)

Belgium

Wulpen

1.9

India

Bangalore (planned)

36

Namibia

Windhoek

5.5

United States United States United States

Big Spring, Texas Upper Occoquan, Virginia Orange County, California

3 54 40

United Kingdom

Langford

10.5

Singapore

Singapore

122

South Africa

Malahleni

4.2

Description of Advanced System for Potable Reuse Reclaimed water is returned to the aquifer before being reused as a potable water source Reclaimed water will be blended in the reservoir, which is a major drinking water source Reclaimed water is blended with conventionally-treated surface water for potable reuse Reclaimed water is blended with raw surface water for potable reuse Reclaimed water is blended in the reservoir, which is a major drinking water source Reclaimed water is returned to the aquifer before being reused as a potable water source Reclaimed water is returned upstream to a river, which is the potable water source Reclaimed water is blended in the reservoir, which is a major drinking water source Reclaimed water from a mine is supplied as drinking water to the municipality

Case Study [Belgium-Recharge] [India-Bangalore] (NAS, 2012) [US-TX-Big Spring] [US-VA-Occoquan] [US-CA-Orange County] [United KingdomLangford] [Singapore-NEWater] [South Africa-eMalahleni Mine]

Source: Adapted from Von Sperling and Chernicharo (2002)

The rationale for DPR is based on the technical ability to reliably produce purified water that meets all drinking water standards and the need to secure dependable water supplies in areas that have, or are expected to have, limited and/or highly variable sources. A unique DPR project has been successful aboard the International Space Station [US-TX-NASA]. However, although reclaimed water can be treated to meet all applicable standards, DPR still raises a number of issues and requires a careful examination of regulatory requirements, health concerns, project management and operation, and public perception. Many of these issues have been discussed in greater detail with respect to how regulatory agencies and utilities in California would pursue DPR as a viable option in the future (Crook, 2010).

provides a graphical representation of IPR with specific examples. There are specific regulatory programs that may be referenced for this practice, and additional discussion on regulatory approaches to planned IPR is provided in Section 4.5.2.10. In either case, the decision to pursue planned IPR typically involves the following factors. 

Limited availability sources



High cost of developing alternate water sources



Conscious or unconscious public acceptance



3.7.1 Planned Indirect Potable Reuse (IPR)

Confidence in, and some level of control over, both advanced reclaimed water treatment processes and water treatment processes

Planned IPR involves a proactive decision by a utility to discharge or encourage discharge of reclaimed water into surface water or groundwater supplies for the specific purpose of augmenting the yield of the supply. For the purposes of the discussion related to planned IPR, it is useful to examine Figure 3-7, which

In some cases, the level of reclaimed water treatment required to meet water quality standards is considerable. The incentive to provide additional treatment may be driven by regulations intent on protecting water supplies but in most cases is also

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and

yield

of

alternate

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Figure 3-7 Planned IPR scenarios and examples

linked to benefits to the discharger or community in increasing the yield of water supplies that they depend on either directly or indirectly. While satisfying these four factors may be necessary to pursue IPR, they are not sufficient. Two specific components of these factors typically control the viability of implementation. First, even though existing water supplies may be of limited availability and yield, the means via water rights, permits, and storage contracts must exist to reap the benefits of withdrawing the additional yield of the augmented water supply. Second, public acceptance of IPR is of paramount importance but sometimes takes counterintuitive turns based on the specifics of the project and the local community. The following examples illustrate how these key components can play out in project planning and implementation. An often-cited example of IPR is the UOSA discharge into Occoquan Reservoir in Northern Virginia. In this particular case, serious water quality issues were caused by multiple small effluent discharges into the reservoir. The Fairfax County Water Authority withdraws water from the reservoir to meet the water supply needs of a large portion of Northern Virginia. In

2012 Guidelines for Water Reuse

1971, the UOSA was formed to address the water quality problem by the same local government entities that relied on the reservoir for their water supply. Therefore, these local governments, and by proxy their residents, received the benefits of the investments of additional wastewater treatment, satisfying the first key component that their water supply was now both protected and augmented. Regarding the second key component, the improvements made a dramatic improvement in the water quality of the reservoir that was readily visible to the general public. Algae blooms, foul odors, low DO for fish, etc., were addressed by the regionalization and advanced treatment and provided the public with a tangible example showing improved water quality over past practices. See [USVA-Occoquan] for further information. Another example is the Gwinnett County, Ga., where treated effluent is discharged to Lake Lanier. Operated by the USACE, Lake Lanier is formed by Buford Dam on the Chattahoochee River north of Atlanta. Gwinnett County, along with several other communities around the lake, withdraws all of its water for potable supply from Lake Lanier. Given the linkage between the water withdrawal from the lake and the desire to return

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reclaimed water to the lake, the first key component was satisfied by the issuance of a revised state withdrawal permit and amended USACE storage contract that provided credit for the water returned. In this case, the key issue focused on permitting the discharge and on the multiple administrative and legal challenges identified by stakeholders with interest in the lake. Because the focus of the stakeholders was primarily lake quality, discharge limits were significantly reduced from already-low proposed levels. For example, the proposed 0.13 mg/L total phosphorus limit based on detailed lake modeling was eventually reduced through the legal and permitting process to 0.08 mg/L using anti-degradation regulations as the rationale. Interestingly, plaintiffs also successfully pushed for the outfall to be closer to the county’s raw water intake to ensure that the reclaimed water discharge would be as reliable as possible. In other example IPR projects, including San Diego and Tampa, the issue of supply and demand was not a significant concern, as the ability of the dischargers to utilize the reclaimed water to augment their yields was confirmed early in the planning process. However, unlike Gwinnett County, the primary opposition to IPR was related to the perceived health risks to the public from drinking the treated drinking water from the blended source. Public opposition of this type has significantly delayed or tabled many IPR plans. In many cases the opposition appears to be rooted, in part, to the public’s perception of the quality of the existing water source and that it will be degraded by the addition of reclaimed water. San Diego was able to provide new educational communication materials to the public and interest groups and is operating an IPR demonstration facility to provide specific data for permitting to augment the San Vicente Reservoir with recycled water [US-CA-San Diego]. Additional information on public information campaigns is provided in Chapter 8.

3.7.2 Direct Potable Reuse (DPR) To date, no regulations or criteria have been developed or proposed specifically for DPR in the United States. Past regulatory evaluations of this practice generally have been deemed unacceptable due to a lack of definitive information related to public health protection. Still, the de facto reuse of treated wastewater effluent as a water supply is common in many of the nation’s water systems, with some drinking water treatment plants using water with a

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large fraction originating as wastewater effluent from upstream communities, especially under low-flow conditions (NRC, 2012). Considering that unplanned reuse is already widely practiced, DPR may be a reasonable option based on significant advances in treatment technology and monitoring methodology in the last decade and health effects data from IPR projects and DPR demonstration facilities. For example, the water quality and treatment performance data generated at operational IPR projects such as Montebello Forebay [US-CA-Los Angeles County] (WRRF, 2011b), Water Factory 21/Orange County Groundwater Replenishment Project [US-CA-Orange County], Occoquan Reservoir [US-VA-Occoquan], Scottsdale Water Campus, and El Paso Water Utility Hueco Bolson augmentation indicate that the advanced wastewater treatment processes in place in these projects can meet the required purification level. In addition to addressing the technical challenges of potable reuse, these projects, as well as San Diego, Calif., CA IPR Demonstration Project [US-CA-San Diego] and Big Spring, Texas, direct blending project [US-TX-Big Spring], demonstrate recent public acceptance of these kinds of water supply projects.

3.7.2.1 Planning for DPR A number of recent publications have focused on identifying the role that DPR will have in the management of water resources in the future (Tchobanoglous et al., 2011; NRC, 2012; Crook, 2010; Leverenz et al., 2011; Schroeder et al., 2012). For the purposes of the discussion related to planned DPR in this section, it is useful to examine Figure 3-8, which provides a graphical representation of DPR, according to the definitions provided in this document, with specific examples. As defined herein, DPR refers to the introduction of purified water, derived from municipal wastewater after extensive treatment and monitoring to assure that strict water quality requirements are met at all times, directly into a municipal water supply system. The resultant purified water could be blended with source water for further water treatment or could be used in direct pipe-to-pipe blending, providing a significant advantage of utilizing existing water distribution infrastructure. Tchobanoglous et al. (2011) proposed a general process flow for alternative potable reuse strategies, which is the basis for Figure 3-8 and in which two DPR options are available.

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Figure 3-8 Planned DPR and specific examples of implementation

In the first option, purified water is first placed in an engineered storage buffer; from there, purified water is blended with the water supply prior to water treatment. In the second option, purified water, without the use of an engineered storage buffer, can be blended back into the distribution system for delivery to water users. An in-depth discussion of implementation of these options is provided by Tchobanoglous et al. (2011) and Levernez et al. (2011), along with the concept and role of the engineered storage buffer, which is a mechanism for detention to provide response time for any off-specification product water. Multiple additional process configurations may be available, such as the configuration in Big Spring, Texas, where direct blending of highly-treated reclaimed water with quality higher than drinking water standards is provided in a raw, surface water transmission main supplying six different community surface water treatment plants. In this particular project, the low TDS DPR water blends in the

2012 Guidelines for Water Reuse

transmission main with significantly higher TDS lake water, improving the blended source water quality [USTX-Big Spring]. In many parts of the world, DPR may be the most economical and reliable method of meeting future water supply needs. While DPR is still an emerging practice, it should be evaluated in water management planning, particularly for alternative solutions to meet urban water supply requirements that are energy intensive and ecologically unfavorable. This is consistent with the established engineering practice of selecting the highest quality source water available for drinking water production. Specific examples of energy-intensive or ecologically-challenging projects include interbasin water transfer systems, which can limit availability of local water sources for food production, and source area ecosystems, which are often impacted by reduced stream flow and downstream water rights holders who could exercise legal recourse to regain lost water. In some

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circumstances, in addition to the high energy cost related to long-distance transmission of water, long transmission systems could be subject to damage from earthquakes, floods, and other natural and human-made disasters. Desalination is another practice for which DPR could serve as an alternative, because energy requirements are comparatively large, and brine disposal is a serious environmental issue. By comparison, DPR using similar technology will have relatively modest energy requirements and provide a stable local source of water. It is important to note, however, that DPR will not be a stand-alone water supply. Therefore, in managing water supplies, other local sources will need to be combined with DPR to create reliable, robust, sustainable water supplies. While the technical issues of DPR can be easily addressed through advanced treatment, there lies the significant task of developing public education and outreach programs to achieve public acceptance of this practice. The San Diego Phase II demonstration project is a key example of the level of effort that is required to achieve support for DPR, with nearly half of the project funding being dedicated to the purpose of education and outreach [US-CA-San Diego]. Successful operation of the Orange County Groundwater Replenishment Project for more than 3 years has accommodated innumerable tours and hosted many national reporters with positive education and feedback from most participants [US-CA-Orange County].

3.7.2.2 Future Research Needs There are several existing potable reuse projects in the United States and abroad. Past research and operational data from existing IPR facilities indicate that available technology can reduce chemical and microbial contaminants to levels comparable to or lower than those present in many current drinking water supplies. Notwithstanding the demonstrated safety of using highly-treated reclaimed water for IPR, there are areas of research that could further advance the safety, reliability, and cost-effectiveness of IPR and more clearly determine the acceptability of DPR as it relates to public health protection. Other future research needs may be related to new or alternative treatment unit processes or treatment trains that are proposed, regulatory requirements (e.g., constituent limits, monitoring, and analytical techniques), public acceptance, and other factors.

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The NRC report identified several key research needs related to both nonpotable and potable reuse, which are summarized below (NRC, 2012): 

Quantify the extent of de facto (unplanned) potable reuse in the United States



Address critical gaps in the understanding of health impacts of human exposure to constituents in reclaimed water



Enhance methods for assessing the human health effects of chemical mixtures and unknowns



Strengthen waterborne disease surveillance, investigation methods, governmental response infrastructure, and epidemiological research tools and capacity



Quantify the nonmonetized costs and benefits of potable and nonpotable water reuse compared with other water supply sources to enhance water management decision-making



Examine the public acceptability of engineered multiple barriers compared with environmental buffers for potable reuse



Develop a better understanding of contaminant attenuation in environmental buffers and wetlands



Develop a better understanding of the formation of hazardous transformation products during water treatment for reuse and ways to minimize or remove them



Develop a better understanding of pathogen removal efficiencies and the variability of performance in various unit processes and multi-barrier treatment, and develop ways to optimize these processes



Quantify the relationship between polymerase chain reaction detections and infectious organisms in samples at intermediate and final stages



Develop improved techniques and data to consider hazardous events or system failure in risk assessment of water reuse

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Chapter 3 | Types of Reuse Applications





Identify better indicators and surrogates that can be used to monitor process performance in reuse scenarios and develop online real-time or near real-time monitoring techniques for their measurement Analyze the need for new reuse approaches and technology in future water management

3.8 References

American Boiler Manufacturers Association. 2005. Boiler Water Quality Requirements and Associated Steam Quality for Industrial/Commercial and Institutional Boilers. ABMA. Vienna, VA. American Water Works Association (AWWA). 2010. “New Orleans Plans to Restore Wetlands Using Effluent Have ‘Wow’ Factors.” Streamlines. 2(24). American Society of Civil Engineers (ASCE). 2012. Agricultural Salinity Assessment and Management, Manuals of Practice (MOP) 71. ASCE Press. Reston, VA. Associated Press. 2012. “Federal Court Rejects Challenge to Arizona Snowbowl’s Mountain Snow-making Plan,” Arizona Capital Times, February 10, 2012. Barber, L. B., A. M. Vajda, C. Douville, D. O. Norris, and J. H. Writer. 2012. Fish Endocrine Disruption Responses to a Major Wastewater Treatment Facility Upgrade. Environmental Science & Technology. 46(4):2121-2131. Baydal, D. 2009. “Municipal Wastewater Recycling Survey.” California Water Recycling Funding Program (WRFP). Retrieved on August 23, 2012 from Bryk, J., R. Prasad, T. Lindley, S. Davis, and G. Carpenter. 2011. National Database of Water Reuse Facilities: Summary Report. WateReuse Foundation. Alexandria, VA. California Department of Public Health. 2009. Water Recycling Criteria. California Code of Regulations. Retrieved on August 23, 2012 from . California State Water Resources Control Board (California SWRCB). 2009. Recycled Water Policy. Retrieved July 2012, from Cirelli, G. L., S. Consoli, F. Licciardello, R. Aiello, F. Giuffrida, and C. Leonardi. 2012. Treated Municipal

2012 Guidelines for Water Reuse

Wastewater Reuse in Vegetable Production. Agricultural Water Management. 104:163. Clark, C. E., and J. A. Veil. 2009. Produced Water Volumes and Management Practices in the United States. Argonne, Illinois: Argonne National Laboratory. Retrieved August 23, 2012 from . Cooper, N. B., A. G. Fishbeck, and T. Barker. 2011. “Extreme Water Reuse – Water Recycling in a Food Products Industry.” WateReuse Association Symposium, October 19, 2011. Crook, J. 2010. Regulatory Aspects of Direct Potable Reuse in California. National Water Research Institute. Fountain Valley, CA. Dobrowolski, J., M. O’Neill, L. Duriancik, and J. Throwe (eds.). 2008. Opportunities and Challenges in Agricultural Water Reuse: Final report. USDA-CSREES. Dobrowolski, J. P., M. P. O’Neill, and L. F. Duriancik. 2004. Agricultural Water Security Listening Session: Final Report, September 9-10, 2004, Park City, UT. USDA Research, Education, and Economics. East Bay Municipal Utility District. 2008. Watersmart Guidebook: A Water-Use Efficiency Plan-Review Guide For New Businesses. EBMUD. Oakland, CA. Florida Department of Environmental Protection (FDEP). 2011. 2010 Reuse Inventory. Florida Department of Environmental Protection. Tallahassee, FL. Retrieved January 2012 from . Food and Agriculture Organization of the United Nations (FAO). 2011. Executive Summary. Thirty-seventh Session Rome 25 June – 2 July 2011. The State of the World’s Land and Water Resources for Food and Agriculture (SOLAW). Food and Agriculture Organization of the United Nations (FAO). 1985. FAO Irrigation and Drainage Paper, 29 Rev. 1. Food and Agriculture Organization of the United Nations: Rome, Italy. Gadson, J. C., D. V. Darshane, C. J. Wojna, and H. Chin. 2012. “Safe and Sustainable Water for the Future through Recovery and Reuse of Beverage Process Water.” WateReuse Association Symposium, September 10, 2012. Global Water Intelligence (GWI). 2011. Produced Water Market: Opportunities in the Oil, Shale and Gas Sectors in North America. Media Analytics Ltd. Oxford, UK. Global Water Intelligence (GWI). 2009. Municipal Water Reuse Markets 2010. Media Analytics Ltd. Oxford, UK.

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Golf Course Superintendents Association of America (GCSAA) and The Environmental Institute for Golf (GCSSA and EIFG). 2009. Golf Course Environmental Profile, Volume II, Water Use and Conservation Practices on U.S, Golf Courses. GCSAA. Lawrence, KS. Retrieved on August 23, 2012 from . Grinnell, G. K., and R. G. Janga. 2004. Golf Course Reclaimed Water Marketing Survey. American Water Works Association. Denver, CO. Hall, J. R., III; D. R. Chalmers; D. W. McKissack; P. R. Carry; and M. M. Monnettand. 2009. Characterization of Turfgrass Nutrient Management Practices in Virginia. Virginia Cooperative Extension. Virginia Polytechnic Institute and State University. Harivandi, A. 2011. “Purple Gold - A Contemporary View of Recycled Water Irrigation.” Green Section Record. 49. Hey, D. L.; D. L. Montgomery, and L. S. Urban. 2004. “Flood Damage Reduction in the Upper Mississippi River Basin – An Ecological Alternative.” The Wetlands Initiative. Chicago, IL. Idelovitch, E. (1981) Unrestricted Irrigation with Municipal Wastewater, in: Proceedings, National Conference on Environmental Engineering, ASCE, Atlanta GA. Inbar Y. 2007. “New standards for treated wastewater reuse in Israel.” In: Zaidi M. (Ed.). Wastewater Reuse – Risk Assessment, Decision-Making and Environmental Security Springer, Dordrecht, Netherlands. International Life Sciences Research Institute Research Foundation (ILSRIF). 2012. Guidelines for Water Recovery in Beverage Production Facilities. Washington, D.C., USA. In press. Kenny, J. F., N. L. Barber, S. S. Hutson, K. S. Linsey, J. K. Lovelace, and M. A. Maupin. 2009. Estimated Use of Water in the United States in 2005. United States Geological Survey (USGS). Retrieved August 2012 from . Leverenz, H. L., G. Tchobanoglous, and T. Asano. 2011. Direct Potable Reuse: A Future Imperative. Journal of Water Reuse and Desalinization. 1(1):2-10. Lazorchak and Smith. 2004. National Screening Survey of EDCs in Municipal Wastewater Treatment Effluents. EPA/600/R-04/171. Environmental Protection Agency. Washington, D.C. Miller, W. G, 2006. Integrated Concepts in Water Reuse: Managing Global Water Needs, Desalination (187: 65-75).

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National Research Council (NRC). 2012. Water Reuse: Potential for Expanding the Nation’s Water Supply Through Reuse of Municipal Wastewater. The National Academies Press: Washington, D.C. National Research Council (NRC). 2010. Management and Effects of Coalbed Methane Produced Water in the United States. The National Academies Press: Washington, D.C. O’Neill, M. P. and J. P. Dobrowolski. 2011. “Water and Agriculture in a Changing Climate.” HortScience. 46:155. Raisbeck, M. F., S. L. Riker, C. M. Tate, R. Jackson, M. A. Smith, K. J. Reddy, and J. R. Zygmunt. 2011. Water Quality for Wyoming Livestock & Wildlife, A Review of the Literature Pertaining to Health Effects of Inorganic Contaminants. B1183. University of Wyoming Department of Veterinary Sciences, UW Department of Renewable Resources, Wyoming Game and Fish Department, and Wyoming Department of Environmental Quality. Rowe, D. R., and I. M. Abdel-Magid. 1995. Handbook of Wastewater Reclamation and Reuse. CRC Press. Boca Raton, FL. Schroeder, E.; G. Tchobanoglous; H. L. Leverenz; and T. Asano. 2012. “Direct Potable Reuse: Benefits for Public Water Supplies, Agriculture, the Environment, and Energy Conservation.” National Water Research Institute (NWRI) White Paper, NWRI-2012-01. National Water Research Institute. Fountain Valley, CA. Scott, C. A., N. I. Faruqui, and L. Raschid-Sally. 2004. Wastewater Use in Irrigated Agriculture: Confronting the Livelihood and Environmental Realities. IWMI, IRDC-CRDI, CABI Publishing. Trowbridge, UK. Sheikh, B., R. C. Cooper, and K. E. Israel. 1999. “Hygienic Evaluation of Reclaimed Water Used To Irrigate Food Crops—A Case Study.” Water Science Technology. ,40(45):261. Sheikh, B., R. P. Cort, W.R. Kirkpatrick, R. S. Jaques, and T. Asano. 1990. “Monterey Wastewater Reclamation Study for Agriculture.” Research Journal of the Water Pollution Control Federation. 62(3):216. Solley, W. B.; R. R. Pierce; and H. A. Perlman. 1998. “Estimated Use of Water in the United States in 1995.” U.S. Geological Survey Circular, 1200. Tchobanoglous, G.; H. L. Leverenz; M. H. Nellor; and J. Crook. 2011. Direct Potable Reuse: The Path Forward. WateReuse Research Foundation and Water Reuse California. Washington, D.C.

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Chapter 3 | Types of Reuse Applications

Thomas, J. C., R. H. White, J. T. Vorheis, H. G. Harris, and K. Diehl. 2006. “Environmental Impact of Irrigating Turf With Type I Recycled Water.” Agronomy Journal Online.

and Standards for Potable Reuse and Feasible Alternatives. EPA 570/9-82-005. Environmental Protection Agency. Washington, D.C.

U.S. Department of Energy (DOE). n.d. Produced Water Management Information System. Retrieved on September 5, 2012, from .

Von Sperling, M. and C. A. L. Chernicharo. 2002. “Urban Wastewater Treatment Technologies and the Implementation of Discharge Standards in Developing Countries.” Urban Water. 4(1): 105.

U.S. Environmental Protection Agency (EPA). n.d. Clean Water State Revolving Fund Green Project Reserve - Case Study: Albany-Millersburg Talking Water Gardens, A ValueFocused Approach to Improving Water Quality. EPA-832-F12-022. Retrieved August 2012, from .

Wade, T. J.; R. L Calderon; K. P. Brenner; E. Sams; M. Beach; R. Haugland; L. Wymer; and A. P. Dufour. 2008. “High sensitivity of children to swimming-associated gastrointestinal illness.” Epidemiology. 19(3):375.

U.S. Environmental Protection Agency (EPA). 2011. Draft Recreational Water Quality Criteria 820-D-11-002. Retrieved August 2012, from . U.S. Environmental Protection Agency (EPA). 2006a. Economic Benefits of Wetlands. EPA 843-F-06-004. Environmental Protection Agency, Office of Water. Washington, D.C. U.S. Environmental Protection Agency (EPA). 2006b. Process Design Manual - Land Treatment of Municipal Wastewater Effluents. EPA/625/R-06/016 EPA Environmental Protection Agency. Cincinnati, OH. U.S. Environmental Protection Agency (EPA). 2004. Guidelines for Water Reuse. EPA/625/R-04/108. Environmental Protection Agency. Washington, D.C. U.S. Environmental Protection Agency (EPA). 1982. Report of Workshop Proceedings, Protocol Development: Criteria

2012 Guidelines for Water Reuse

Wade, T. J., E. Sams, K. P. Brenner, R. Haugland, E. Chern, M. Beach, L. Wymer, C. C. Rankin, D. Love, Q. Li, R. Noble, and A. P. Dufour. 2010. “Rapidly Measured Indicators of Recreational Water Quality and Swimming-associated Illness at Marine Beaches: a Prospective Cohort Study.” Environmental Health 9(66):1. WateReuse Research Foundation. (WRRF) 2011a. Attenuation of Emerging Contaminants in Stream Augmentation with Recycled Water. WRF Report 06-20-1. WateReuse Foundation. Alexandria, VA. WateReuse Research Foundation (WRRF). 2011b. Development and Application of Tools to Assess and Understand the Relative Risks of Regulated Chemicals in Indirect Potable Reuse Projects – The Montebello Forebay Groundwater Recharge Project. Tools to Assess and Understand the Relative Risks of Indirect Potable Reuse and Aquifer Storage & Recovery Projects, Volume 1A. WRF-06018-1A. WateReuse Research Foundation, Alexandria, VA. World Health Organization (WHO). 2006. WHO Guidelines For The Safe Use Of Wastewater, Excreta and Greywater. United Nations Environment Program. Paris.

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2012 Guidelines for Water Reuse

CHAPTER 4 State Regulatory Programs for Water Reuse This chapter presents an overview of the overarching approach to developing a reuse program at the state level, a regulatory framework outlining fundamental components for states considering developing or revising regulations, and a summary of which states have regulations and guidelines governing reuse. This chapter also provides a listing of the existing state water reuse regulations or guidelines in 10 sample states (Arizona, California, Florida, Hawaii, Nevada, New Jersey, North Carolina, Texas, Virginia, and Washington) for a comparison of approaches governing different types of reuse applications. Finally, the chapter provides suggested regulatory guidelines for water reuse.

4.1 Reuse Program Framework

Since publication of the 2004 guidelines, several states have developed state water reuse programs, building on the examples of other states with wellestablished water reuse programs, such as Florida, California, Texas, and Arizona. Establishing an effective state water reuse program involves a number of complex factors beyond establishing guidelines or regulations. There are 15 key elements to an effective state water reuse program, as presented in Table 4-1.

4.2 Regulatory Framework

Reuse programs operate within a framework of regulations that must be addressed in the earliest stages of planning. A thorough understanding of all applicable regulations is required to plan the most effective design and operation of a water reuse program and to streamline implementation. Currently, there are no federal regulations directly governing water reuse practices in the United States. In the absence of federal standards and regulations, each state may choose to adopt rules and develop

2012 Guidelines for Water Reuse

programs for water reuse to meet its specific resource needs, and to ensure that water reuse projects are designed, constructed, and operated in a manner protective of the environment, other beneficial uses, and human health. Water reuse regulations and guidelines have been developed by many states, as described in Section 4.5. Regulations refer to actual rules that have been enacted and are enforceable by governmental agencies. Guidelines, on the other hand, are generally not enforceable, but can be used in the development of a reuse program. In some states, however, guidelines are, by reference, included in the regulations, and thus are enforceable. In addition to providing treatment and water quality requirements, comprehensive rules or guidelines also promote reuse by providing the playing field for which projects must comply. They provide the certainty that if a project meets the requirements, it will be permitted. Table 4-2 provides fundamental components of a regulatory framework that states may want to consider when developing or amending rules or regulations for water reuse.

4.3 Relationship of State Regulatory Programs for Water Reuse to Other Regulatory Programs

States’ regulatory programs for water reuse must be consistent with and, in some cases, function within the limitations imposed by other federal and state laws, regulations, rules, and policies. The following subsections describe some of the more common laws and regulations that can affect states’ regulatory programs for water reuse. Laws, policies, rules, and regulations that affect state water reuse regulatory programs include water rights laws, water use, and wastewater discharge regulations, as well as laws that restrict land use and protect the environment.

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Table 4-1 Key elements of a water reuse program (Adapted from WateReuse Association, 2009) 1 2 3

Factor Establish the objectives Commit to the long run Identify the lead agency or agencies

4

Identify water reuse leader

5

Enact needed legislation

6

Adopt and implement rules or guidelines governing water reuse

7

Be proactive

8

Develop and cultivate needed partnerships

9

Ensure the safety of water reuse

10

Develop specific program components Focus on quality, integrity, and service

11

12

Be consistent

13

Promote a water reuse community

14

Maintain a reuse inventory

15

Address cross-connection control issues

4-2

Description Objectives that encourage and promote reuse should be clear and concise. A water reuse program should be considered a permanent, high-priority program within the state. The lead agencies should be able to issue permits for the production, distribution, and use of the reclaimed water. These permits are issued under state authority and are separate from the federal requirements for wastewater discharges to surface waters under the NPDES permit program. Preference to the lead agency determination should be given to the public health agency since the intent of the use of reclaimed water is for public contact and/or consumption following adequate and reliable treatment. A knowledgeable and dedicated leader of the water reuse program who develops and maintains relationships with all water programs and other agencies should be designated. Initial legislation generally should be limited to a clear statement of the state objectives, a clear statement of authorization for the program, and other authorizations needed for implementation of specific program components. States also will want to review and evaluate existing state water law to determine what constraints, if any, it will impose on water reuse and what statutory refinements may be needed. With stakeholder involvement, a comprehensive and detailed set of reuse regulations or guidelines that are fully protective of environmental quality and public health should be developed and adopted in one location of the regulations. Formal regulations are not a necessity—they may be difficult and costly to develop and change and therefore overly rigid. Frameworks that have an ability to adapt to industry changes are most effective. The water reuse program leader should be visible within the state and water reuse community while permitting staff of the lead agency must have a positive attitude in reviewing and permitting quality water reuse projects. Partnerships between the agency responsible for permitting the reclaimed water facilities (usually the lead agency) and the agency(ies) responsible for permitting water resources as well as the agency responsible for protection of public health are critical. Other agency partnerships, such as with potential major users of reclaimed water such as the department of transportation, are also helpful in fostering state-wide coordination and promotion of water reclamation. Ensuring the protection of public health and safety can be accomplished by placing reliance on production of highquality reclaimed water with minimal end use controls, or allowing lower levels of treatment with additional controls on the use of reclaimed water (setback distances, time of day restrictions, limits on types of use, etc.), or by a combination of both types of regulations. A formal reliability assessment to assure a minimum level or redundancy and reliability to review and detail operating standards, maintainability, critical operating conditions, spare parts requirements and availability, and other issues that affect the ability of the plant to continuously produce reclaimed water. A critical component to ensuring the safety of reclaimed water for public access and contact-type reuse is defining requirements for achieving a high level of disinfection and the monitoring program necessary to ensure compliance (this is described further in Chapter 6). Program components are going to differ from state to state and maturity of the reuse program. Not only should the reclaimed water utilities implement high-quality reuse systems that are operated effectively, but the lead agency should also model this commitment to quality and prompt service to the regulated and general public regarding reuse inquiries and permitting issues. In effect, the lead agency should focus on building same level of trust public potable water systems develop and re-establish daily. A comprehensive and detailed set of state regulations, as well as having a lead reuse role, help keep the permitting of reuse systems consistent. If there are multiple branches around the state involved in permitting, training and other measures of retaining consistency must be taken. The lead agency should be proactive in developing and maintaining the state’s water reuse community—reuse utilities, consulting engineers, state agencies, water managers, health departments, universities, researchers, users of reclaimed water, and others—in an effort to disseminate information and obtain feedback related to possible impediments, issues, and future needs. Active participation in the national and local reuse organizations is valuable. Maintenance of a periodical (e.g., annual) reuse inventory is essential in tracking success of a state’s water reuse program. Facilities in Florida that provide reclaimed water are required by their permits to submit an annual reuse report form every year. That data not only is used in the states annual reuse inventory report and reuse statistics but is also shared with the WateReuse Association’s National Reuse Database. Coordination and joint activity between agencies and within agencies (drinking water program, wastewater program, water reuse program, etc.) must be taken to address cross-connection control issues (this is described further in Chapter 2).

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Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-2 Fundamental components of a water reuse regulatory framework for states Category Purpose and/or goal statement Definitions Scope and applicability Exclusions and prohibitions

Variances

Permitting requirements

Define or refine control and access to reclaimed water Relationship to other rules Relationship to stakeholders Relationship to regulations or guidelines for uses of other nonconventional water sources Reclaimed water standards Treatment technology requirements Monitoring requirements Criteria or standards for design, siting, and construction

Comment  Frame the state's purpose for developing the rule or regulation (e.g., to satisfy a need or fulfill a statutory requirement), and describe the ultimate vision for the water reuse program. The process to authorize, develop, and implement rules or changes to rules is time consuming and costly. After adoption, rules are difficult to change, which limits the ability to accommodate new technologies and information.  Define type of use and other water reuse-related terms used within the body of the rule or regulation.  Define the scope and applicability of the rules or regulations that delineates what facilities, systems, and activities are subject to the requirements of the rules or regulations.  Include grandfathering or transitioning provisions for existing facilities, systems, or activities not regulated prior to the adoption of the rules or regulations.  Describe facilities, systems and activities that are 1) not subject to the requirements of the rules or regulations, and 2) specifically prohibited by the rules or regulations.  Describe procedures for variances to design, construction, operation, and/or maintenance requirements of the regulation for hardships that outweigh the benefit of a project, and the variance, if granted, would not adversely impact human health, other beneficial uses, or the environment. These variance procedures give regulators flexibility to consider projects that may deviate only minimally from the requirements with no significant adverse impact or opportunities that are not anticipated during initial development of a regulation. Since variances need to be based on sound, justifiable reasons for change, regulatory programs should develop guidance on how to develop adequate justification that can be relied upon as precedence setting for future regulatory decisions and actions.  Describe the permitting framework for water reuse. Indicate whether the water reuse rule or regulation will serve as the permitting mechanism for water reuse projects or identify other regulations through which the water reuse rule or regulation will be implemented and projects permitted.  Describe if or how end users of reclaimed water will be permitted, and rights of end user to refuse reclaimed water if not demanded.  Describe permit application requirements and procedures. Specify all information that the applicant must provide in order to appropriately evaluate and permit the water reuse projects.  Determine the rights to and limits of access and control over reclaimed water for subsequent use and the relationship between the underlying water right, wastewater collection system ownership, reclamation plant ownership, and downstream water users who have demonstrated good-faith reliance on the return of the wastewater effluent into a receiving stream within the limits and requirements of the state’s water rights statutory and regulatory requirements.  Describe relationship between water reuse rule or regulation and, for example, water and wastewater regulations, environmental flow requirements, solid waste or hazardous waste rules, groundwater protection, required water management plans, and relevant health and safety codes for housing, plumbing, and building.  Identify regulatory or non-regulatory stakeholders from various sectors (e.g., water, wastewater, housing, planning, irrigation, parks, ecology, public health, etc.) that have a role or duty in the statewide reuse program.  Describe other rules or regulations that exist for graywater recycle and stormwater or rainwater harvesting and use.  Some states may choose to develop a more comprehensive approach that encompasses rules or regulations for all nonconventional water sources, including water reuse, within one set of rules or regulations.  See Tables 4-6 to 4-15 for standards that are either defined by end use or by degree of human contact.  Include a provision to evaluate and allow standards to be developed on a case-by-case basis for less common uses of reclaimed water that are not listed.  Require points of compliance to be established to verify compliance with standards.  Describe response and corrective action for occurrence of substandard reclaimed water (a component of the Contingency Plan, below).  In addition to reclaimed water standards, some states specify treatment technologies for specific reuse applications.  Describe methods and frequency for monitoring all standards listed in the rules or regulations.  Describe criteria or standards of engineering design, siting, and construction for water reuse facilities and systems that typically include, but are not limited to, facilities or systems to treat/reclaim, distribute, and store water for reuse.  Develop requirements for dual plumbed distributions systems (separate distribution of potable and nonpotable water) that are co-located.  Describe requirements for the transfer of reclaimed water and its alternative disposal if unsuitable or not required by target user (e.g., during wet seasons).

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Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-2 Fundamental components of a water reuse regulatory framework for states (cont.) Category Construction requirements Operations and maintenance (O&M)

Management of pollutants from significant industrial users as source water protection

Access control and use area requirements

Education and notification Operational flow requirements Contingency plan Recordkeeping Reporting Stakeholder participation Financial assistance

Comment  Describe requirements for engineering reports, pilot studies, and certificates required to construct and to operate.  Describe minimum requirements for the submission and content of O&M manual. The scope and content of an O&M manual will be determined by the type and complexity of the system(s) described by the manual.  Where facilities or systems with inputs from significant industrial users are proposing to generate reclaimed water suitable for human contact or potable reuse, describe programs that must be implemented to manage pollutant of concern from significant industrial users.  Pretreatment programs of combined publicly owned treatment works and reclamation systems may satisfy program requirements.  Develop program requirements for satellite reclamation systems also affected by inputs from significant industrial users.  Such pretreatment programs should develop discharge limits that are intended to protect source water, rather than wastewater treatment and sewer system integrity.  Describe requirements to control access to sites where reclaimed water will be generated, or in some cases, stored or utilized.  Describe requirements for advisory sign placement, message, and size.  Describe requirements for proper use of reclaimed water by end users to ensure protection of the environment and human health (.e.g., setbacks, physical barriers or practices to prevent reclaimed water from leaving the site of use, etc.).  Include requirements for generators or providers of reclaimed water to educate end users of appropriate handling and use of the water, and to provide notification to end users regarding the discharges of substandard water to reuse and loss of service for planned or unplanned cause.  Requirements for maintaining flow within design capacity of treatment system or planning for additional treatment capacity as needed.  Include a requirement for a contingency plan that describes how system failures, unauthorized discharges, or upsets will be remedied or addressed.  Describe what operating records must be maintained, the location where they are retained, and the minimum period of retention.  Describe what items must be reported, the frequency of reporting, and to whom they are reported.  Requirements on public notice, involvement, and decision-making. This will apply where the water reuse rule or regulation is used as the vehicle to permit water reuse projects.  Describe state, local, or federal funding or financing sources.

4.3.1 Water Rights Water reuse regulatory programs must work within the prevailing water rights laws of the state. Each state in the United States was granted ownership and control over all waters within their boundaries at statehood. “Water rights” provide the legal right for an entity to divert, capture, and use water within the boundaries of each individual state. In the United States, there are two main approaches to water rights law— appropriative doctrines (common in historically waterscarce areas) and riparian doctrines (common in historically water-abundant areas). Appropriative water rights are assigned or delegated to consumers, generally based on seniority of which users laid first claim to that water and not from the property’s proximity to the water source. In contrast, riparian water rights are based on the proximity to water and are acquired by the purchase of the land. In the West, reuse can be the target of legal challenges, depending 4-4

on how the local system of water rights regards the use and return of reclaimed water. Access to or control over reclaimed water, like formal water rights, is unique to each individual state. Some states manage access to and use of reclaimed water under their water rights permitting program; others, like the state of Washington, incorporate this management directly with the reclaimed water permit. In this instance, the use of reclaimed water is not granted a separate and new water rights certificate or license, although the use of the reclaimed water cannot harm or impair existing rights that can demonstrate dependence on the return flows. While most owners of water reclamation facilities generally have first rights to the use of the reclaimed water, there are scenarios where the facility is obligated to discharge effluents to receiving water

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Chapter 4 | State Regulatory Programs for Water Reuse

bodies rather than using the reclaimed water for other beneficial uses. These scenarios include: 1) where reduction in effluent discharge flows could be challenged by downstream users, 2) where laws require that place-of-use be located within the watershed from which the water was originally drawn (in the case that reclaimed water might be distributed outside the watershed), 3) where “beneficial uses” of higher priority can make a claim for the reclaimed water (over, for example, industrial reuse), or 4) where reductions in water withdrawals from water supply because of reclamation might change customer rights or allocations in future periods of shortage (where rights or allocations are based on historic usage). The most significant constraint affecting use of reclaimed water is the need to assure minimum instream flows sufficient to protect aquatic habitat. This is especially necessary in locations where instream flows are necessary to protect the habitat of threatened and endangered fisheries. There are also cases where federal water laws may affect or supersede state regulatory programs for water reuse, particularly where water reuse would impact international boundaries (e.g., the Great Lakes, the Tijuana River, the Colorado River), Native American water rights, multiple states with a claim on limited water supplies, water rights on federal property (or on non-reserved lands), instream flow requirements to support threatened and endangered fisheries under the Endangered Species Act (ESA), and other federal reserved water rights. Additional information is available in the 2004 EPA Guidelines for Water Reuse Chapter 5 and Potential for Expanding the Nation’s Water Supply Through Reuse of Municipal Wastewater Chapter 10 (EPA, 2004 and NRC, 2012).

4.3.2 Water Supply and Use Regulations Federal, state, and local entities may set standards for how water may be used as a condition for supply, and these standards can include water use restrictions, water efficiency goals, or water supply reductions. Some of these include criteria for substitution and offset credits associated with use of reclaimed water, and the resulting benefit to the utility provider. Water use restrictions may serve to promote reuse when water users are required to use potable or reclaimed water for only certain uses under specific conditions. Penalties or consequences for noncompliance may include disconnection of service,

2012 Guidelines for Water Reuse

fees, fines, or jail time for major infractions. However, other regulations designed to protect water customers from service termination may mitigate or neutralize such penalties. There are generally provisions to allow prohibited or “unreasonable” uses of potable water when reclaimed water is unavailable, unsuitable for a specific use, uneconomical, or would cause negative environmental impacts. An example of California’s statutory mandate to utilize reclaimed water is provided in Chapter 5 of the 2004 guidelines. Mandatory or voluntary water efficiency goals may be promulgated as part of a holistic water management program, often stimulated by public outreach campaigns and incentives. Mandatory goals may carry penalties as described above for water use restrictions. State-wide efficiency requirements may include incentives for localities to meet targets as a prerequisite for grants, loans, allocations, or other benefits. Water reuse may qualify or be required as water efficiency measures such as allowed under Washington State Department of Health’s Water Use Efficiency program. Water efficiency is discussed further in Chapter 2. Water supply reductions are most often imposed during periods of drought and can trigger the invocation of seniority-based water allocations that can result in reduced allocations for those with more junior rights. Water agencies may adopt tiered pricing and allocation strategies. Water shortages often provide an opportunity to increase public awareness of the costs associated with water supply and may provide a powerful basis to develop a state regulatory program for water reuse, particularly where other methods to augment supply are more costly or have been exhausted.

4.3.3 Wastewater Regulations and Related Environmental Regulations Both the federal government and state agencies exercise jurisdiction over the quality and quantity of wastewater discharge into public waterways of the United States. The primary authority for the regulation of wastewater is the Federal Water Pollution Control Act, commonly referred to as the Clean Water Act (Public Law 92-500). The 1972 CWA assigned the federal government and states specific responsibilities for water quality management designed to make all surface waters “fishable and swimmable.” The CWA requires states to set water quality standards, thus

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Chapter 4 | State Regulatory Programs for Water Reuse

establishing the right to control pollution from WWTPs, as long as such regulations are at least as stringent as federal rules. Major objectives of the CWA are to eliminate all pollutant discharges into navigable waters, stop discharges of toxic pollutants in toxic amounts, develop waste treatment management plans to control sources of pollutants, and to encourage (but not require) water reclamation and reuse through delegation agreements. Primary jurisdiction under the CWA is with EPA, but in most states many provisions of the CWA are administered and enforced by the state water pollution control agencies. Wastewater discharge regulations mostly address treated effluent quality, but can indirectly restrict the quantity of effluent discharged to a receiving body by limiting the pollutant loads resulting from the discharge. Treated wastewater discharge permits are issued pursuant to the NPDES program under the CWA. In addition to limits on the concentration of specific contaminants, discharge permits may also include limits on the total mass of a pollutant discharged to the receiving stream—known as TMDL limits—and on the quality of the water in the receiving stream itself (e.g., minimum DO limits). For reuses that involve a discharge to surface waters, such as IPR or stream augmentation, states may choose to regulate them through the NPDES permit program. In this case, the discharge for the reuse would need to comply, at a minimum, with state surface water quality standards and any TMDLs that would apply to the particular receiving water. Though not specifically addressed, water reuse is encouraged by the CWA. Discharged water quantity may also be regulated locally by terms of the ESA or specific water rights law as described in Section 4.3.1. The ESA has been applied to require water users to maintain minimum flows in western rivers to protect the habitat of various species of fish whose survival is threatened by increases in water demand. Such regulations may be continuous or seasonal, and may or may not correspond to periods associated with reclaimed water demand as required by the NPDES permit. To ensure compliance with the ESA, state regulatory programs for water reuse should establish a process by which projects that will divert all or a portion of a wastewater treatment facility’s effluent from a surface water discharge to consumptive reuse will be coordinated with appropriate federal (i.e., U.S. Fish & Wildlife Service) and state agencies. Consumptive reuse

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refers to reuse that does not return wastewater back to the wastewater treatment facility or reclamation system from which it received reclaimed water.

4.3.4 Drinking Water Source Protection Where reclaimed water may impact drinking water sources, the SDWA comes into play. The SDWA is the main federal law that ensures the quality of Americans' drinking water. Under SDWA, EPA sets national health-based standards, or MCLs, for drinking water quality and oversees the states, localities, and water suppliers that implement those standards. SDWA was originally passed by Congress in 1974 and amended in 1986 and 1996. While the original law focused primarily on treatment standards, the 1996 amendments greatly enhanced the existing law by setting requirements for source water protection. The SDWA’s Source Water Assessment program requires each state to conduct an assessment of its sources of drinking water (rivers, lakes, reservoirs, springs, and groundwater wells) to identify significant potential sources of water quality contamination. State regulatory programs for water reuse must be compatible and consistent with federal and state SDWA regulatory programs to ensure the protection of drinking water sources (surface and ground).

4.3.5 Land Use Several western states have adopted laws that require new developments to adopt sustainable water management plans, which may encourage water reuse [US-AZ-Sierra Vista]. In chronically water-short or environmentally-sensitive areas, use of reclaimed water may even be a prerequisite for new developments.

4.4 Suggested Regulatory Guidelines for Water Reuse Categories

As defined in Chapter 1, water reuse for the purposes of these guidelines refers to the use of treated municipal wastewater (reclaimed water). Many states have rules, regulations or guidelines for a wide range of reclaimed water end uses (or reuses), and prescribe different requirements for different reuses. This subsection examines categories of water reuses and suggested regulatory guideline for the water reuses in these categories.

2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

4.4.1 Water Reuse Categories For the purposes of this chapter, the most common water reuses regulated by states have been inventoried and divided into water reuse categories as described in Table 4-3. Minimum suggested regulatory guidelines are presented in Table 4-4. Although reuse categories and their descriptions included in an individual state, territory, or tribe’s rules, regulations or guidelines may differ from the reuse categories and descriptions presented in Table 4-3, the purpose of the information provided therein is to facilitate the comparison of existing rules, regulations and guidelines adopted by states, territories, and tribes and suggest minimum regulatory guidelines using common categories.

4.4.2 Suggested Regulatory Guidelines

Table 4-4 presents suggested treatment processes, reclaimed water quality, monitoring frequency, and setback distances for water reuses in various categories. These guidelines apply to domestic wastewater from municipal or other wastewater treatment facilities having a limited input of industrial waste. The suggested regulatory guidelines are predicated principally on water reclamation and reuse information from the United States and are intended to apply to reclamation and reuse facilities in the United States. These guidelines may also be used by tribal nations in establishing water reuse programs. Local social, economic, regulatory, technological, and other conditions may limit the applicability of these guidelines in some countries (see Chapter 9).

2012 Guidelines for Water Reuse

4.4.3 Rationale for Suggested Regulatory Guidelines The rationale for the suggested treatment processes, reclaimed water quality, monitoring frequency, and setback distances in porous media is based on: 

Water reuse experience in the United States and elsewhere



Research and pilot plant or demonstration study data



Technical material from the literature



Various states’ reuse rules, regulations, policies, or guidelines



Attainability



Sound engineering practice



Use with a multiple barrier approach

These guidelines are not intended to be used as definitive water reclamation and reuse criteria. They are intended to provide reasonable guidance for water reuse opportunities, particularly in states that have not developed their own criteria or guidelines. Adverse health consequences associated with the use of raw or improperly treated wastewater are well documented. As a consequence, water reuse regulations and guidelines are principally directed at public health protection and generally are based on the control of pathogenic microorganisms for nonpotable reuse applications and control of both health-significant microorganisms and chemical contaminants for IPR applications.

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Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-3 Water reuse categories and number of states with rules, regulations or guidelines addressing these reuse 1 categories

Category of reuse

Number of States or Territories with Rules, Regulations, or Guidelines Addressing Reuse Category

Description Unrestricted

The use of reclaimed water for nonpotable applications in municipal settings where public access is not restricted

32

Restricted

The use of reclaimed water for nonpotable applications in municipal settings where public access is controlled or restricted by physical or institutional barriers, such as fencing, advisory signage, or temporal access restriction

40

Food Crops

The use of reclaimed water to irrigate food crops that are intended for human consumption

27

Processed Food Crops and Non-food Crops

The use of reclaimed water to irrigate crops that are either processed before human consumption or not consumed by humans

43

Unrestricted

The use of reclaimed water in an impoundment in which no limitations are imposed on body-contact water recreation activities (some states categorize snowmaking in this category)

13

Restricted

The use of reclaimed water in an impoundment where body contact is restricted (some states include fishing and boating in this category)

17

Environmental Reuse

The use of reclaimed water to create, enhance, sustain, or augment water bodies, including wetlands, aquatic habitats, or stream flow

17

Industrial Reuse

The use of reclaimed water in industrial applications and facilities, power production, and extraction of fossil fuels

31

Groundwater Recharge – Nonpotable Reuse

The use of reclaimed water to recharge aquifers that are not used as a potable water source

16

Indirect Potable Reuse (IPR)

Augmentation of a drinking water source (surface or groundwater) with reclaimed water followed by an environmental buffer that precedes normal drinking water treatment

9

Direct Potable Reuse (DPR)

The introduction of reclaimed water (with or without retention in an engineered storage buffer) directly into a water treatment plant, either collocated or remote from the advanced wastewater treatment system

0

Urban Reuse

Agricultural Reuse

Impoundments

Potable Reuse

1

Individual state reuse programs often incorporate different terminology so the reader should exercise caution in comparing the categories in these tables directly to state regulatory definitions

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2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse Table 4-4 Suggested guidelines for water reuse Reuse Category and Description Treatment

Reclaimed Water Quality

2

Reclaimed Water Monitoring

Setback Distances

3

Urban Reuse

Unrestricted

The use of reclaimed water in nonpotable applications in municipal settings where public access is not restricted.

 Secondary(4)  Filtration(5)  Disinfection(6)

    

pH = 6.0-9.0 ≤ 10 mg/l BOD (7) ≤ 2 NTU (8) No detectable fecal coliform /100 ml (9,10) 1 mg/l Cl2 residual (min.) (11)

    

pH – weekly BOD - weekly Turbidity - continuous Fecal coliform - daily Cl2 residual – continuous

 50 ft (15 m) to potable water supply wells; increased to 100 ft (30 m) when located in porous media (18)

 At controlled-access irrigation sites where design and operational measures significantly reduce the potential of public contact with reclaimed water, a lower level of treatment, e.g., secondary treatment and disinfection to achieve < 14 fecal coli/100 ml may be appropriate.  Chemical (coagulant and/or polymer) addition prior to filtration may be necessary to meet water quality recommendations.  The reclaimed water should not contain measurable levels of pathogens. (12)  Reclaimed water should be clear and odorless.  Higher chlorine residual and/or a longer contact time may be necessary to assure that viruses and parasites are inactivated or destroyed.  Chlorine residual > 0.5 mg/l in the distribution system is recommended to reduce odors, slime, and bacterial regrowth.  See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.

 Secondary  Disinfection (6)

    

pH = 6.0-9.0 ≤ 30 mg/l BOD (7) ≤ 30 mg/l TSS ≤ 200 fecal coliform /100 ml (9, 13, 14) 1 mg/l Cl2 residual (min.) (11)

    

pH – weekly BOD – weekly TSS – daily Fecal coliform - daily Cl2 residual – continuous

 300 ft (90 m) to potable water supply wells  100 ft (30 m) to areas accessible to the public (if spray irrigation)

 If spray irrigation, TSS less than 30 mg/l may be necessary to avoid clogging of sprinkler heads.  See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.  For use in construction activities including soil compaction, dust control, washing aggregate, making concrete, worker contact with reclaimed water should be minimized and a higher level of disinfection (e.g. < 14 fecal coli/100 ml) should be provided when frequent worker contact with reclaimed water is likely.

 50 ft (15 m) to potable water supply wells; increased to 100 ft (30 m) when located in porous media (18)

 See Table 3-5 for other recommended chemical constituent limits for irrigation.  Chemical (coagulant and/or polymer) addition prior to filtration may be necessary to meet water quality recommendations.  The reclaimed water should not contain measurable levels of pathogens. (12)  Higher chlorine residual and/or a longer contact time may be necessary to assure that viruses and parasites are inactivated or destroyed.  High nutrient levels may adversely affect some crops during certain growth stages.  See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.

Restricted

The use of reclaimed water in nonpotable applications in municipal settings where public access is controlled or restricted by physical or institutional barriers, such as fencing, advisory signage, or temporal access restriction

(4)

Agricultural Reuse Food Crops 15

The use of reclaimed water for surface or spray irrigation of food crops which are intended for human consumption, consumed raw.

 Secondary (4)  Filtration (5)  Disinfection (6)

    

pH = 6.0-9.0 ≤ 10 mg/l BOD (7) ≤ 2 NTU (8) No detectable fecal coliform/100 ml (9,10) 1 mg/l Cl2 residual (min.) (11)

    

pH – weekly BOD - weekly Turbidity - continuous Fecal coliform - daily Cl2 residual – continuous

 Secondary (4)  Disinfection (6)

    

pH = 6.0-9.0 ≤ 30 mg/l BOD (7) ≤ 30 mg/l TSS ≤ 200 fecal coli/100 ml (9,13, 14) 1 mg/l Cl2 residual (min.) (11)

    

pH – weekly BOD - weekly TSS - daily Fecal coliform - daily Cl2 residual – continuous

Processed Food Crops 15

The use of reclaimed water for surface irrigation of food crops which are intended for human consumption, commercially processed.

Non-Food Crops

The use of reclaimed water for irrigation of crops which are not consumed by humans, including fodder, fiber, and seed crops, or to irrigate pasture land, commercial nurseries, and sod farms.

Comments

2012 Guidelines for Water Reuse

 300 ft (90 m) to potable water supply wells  100 ft (30 m) to areas accessible to the public (if spray irrigation)

    

See Table 3-5 for other recommended chemical constituent limits for irrigation. If spray irrigation, TSS less than 30 mg/l may be necessary to avoid clogging of sprinkler heads. High nutrient levels may adversely affect some crops during certain growth stages. See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements. Milking animals should be prohibited from grazing for 15 days after irrigation ceases. A higher level of disinfection, e.g., to achieve < 14 fecal coli/100 ml, should be provided if this waiting period is not adhered to.

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Chapter 4 | State Regulatory Programs for Water Reuse Table 4-4 Suggested guidelines for water reuse Reuse Category and Description Treatment

Reclaimed Water Quality

2

Reclaimed Water Monitoring

Setback Distances

3

Comments

Impoundments

Unrestricted

The use of reclaimed water in an impoundment in which no limitations are imposed on body-contact.

 Secondary (4)  Filtration (5)  Disinfection (6)

    

pH = 6.0-9.0 ≤ 10 mg/l BOD (7) ≤ 2 NTU (8) No detectable fecal coliform/100 mi (9,10) 1 mg/l Cl2 residual (min.) (11)

    

pH – weekly BOD – weekly Turbidity – continuous Fecal coliform - daily Cl2 residual – continuous

 500 ft (150 m) to potable water supply wells (min.) if bottom not sealed

        

Restricted

The use of reclaimed water in an impoundment where body-contact is restricted.

 Secondary  Disinfection (6) (4)

≤ 30 mg/l BOD (7) ≤ 30 mg/l TSS ≤ 200 fecal coliform/100 ml (9,13, 14) 1 mg/l Cl2 residual (min.) (11)

   

pH – weekly TSS – daily Fecal coliform - daily Cl2 residual – continuous

Variable, but not to exceed:  ≤30 mg/l BOD (7)  ≤ 30 mg/l TSS  ≤ 200 fecal coliform/100 ml (9,13, 14)  1 mg/l Cl2 residual (min.) (11)

   

BOD – weekly SS – daily Fecal coliform - daily Cl2 residual – continuous

   

 500 ft (150 m) to potable water supply wells (min.) if bottom not sealed

Dechlorination may be necessary to protect aquatic species of flora and fauna. Reclaimed water should be non-irritating to skin and eyes. Reclaimed water should be clear and odorless. Nutrient removal may be necessary to avoid algae growth in impoundments. Chemical (coagulant and/or polymer) addition prior to filtration may be necessary to meet water quality recommendations. Reclaimed water should not contain measurable levels of pathogens. (12) Higher chlorine residual and/or a longer contact time may be necessary to assure that viruses and parasites are inactivated or destroyed. Fish caught in impoundments can be consumed. See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.

 Nutrient removal may be necessary to avoid algae growth in impoundments.  Dechlorination may be necessary to protect aquatic species of flora and fauna.  See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.

Environmental Reuse Environmental Reuse

The use of reclaimed water to create wetlands, enhance natural wetlands, or sustain stream flows.

 Variable  Secondary (4) and disinfection (6) (min.)

    

Dechlorination may be necessary to protect aquatic species of flora and fauna. Possible effects on groundwater should be evaluated. Receiving water quality requirements may necessitate additional treatment. Temperature of the reclaimed water should not adversely affect ecosystem. See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.

Industrial Reuse  pH = 6.0-9.0  ≤ 30 mg/l BOD (7)  300 ft (90 m) to areas accessible to the Once-through Cooling  ≤ 30 mg/l TSS  Secondary (4)  Windblown spray should not reach areas accessible to workers or the public. public  pH – weekly  ≤ 200 fecal coliform/100 ml (9,13, 14)  BOD – weekly  1 mg/l Cl2 residual (min.) (11)  TSS – weekly Variable, depends on recirculation ratio:  Fecal coliform - daily  Secondary (4)  pH = 6.0-9.0  Windblown spray should not reach areas accessible to workers or the public.  Cl2 residual – continuous (6)  300 ft (90 m) to areas accessible to the  Disinfection  ≤ 30 mg/l BOD (7)  Additional treatment by user is usually provided to prevent scaling, corrosion, biological growths, fouling and public. May be reduced if high level of Recirculating Cooling Towers (chemical coagulation foaming.  ≤ 30 mg/l TSS (5) disinfection is provided. and filtration may be (9,13, 14)  See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.  ≤ 200 fecal coliform/100 ml needed)  1 mg/l Cl2 residual (min.) (11) Other Industrial uses – e.g. boiler feed, equipment washdown, processing, power generation, and in the oil and natural gas production market (including hydraulic fracturing) have requirements that depends on site specific end use (See Chapter 3)

Groundwater Recharge – Nonpotable Reuse The use of reclaimed water to recharge aquifers which are not used as a potable drinking water source.

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 Site specific and use dependent  Primary (min.) for spreading  Secondary (4) (min.) for injection

 Site specific and use dependent

 Depends on treatment and use

 Site specific

    

Facility should be designed to ensure that no reclaimed water reaches potable water supply aquifers. See Chapter 3 of this document and Section 2.5 of the 2004 guidelines for more information. For injection projects, filtration and disinfection may be needed to prevent clogging. For spreading projects, secondary treatment may be needed to prevent clogging. See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.

2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse Table 4-4 Suggested guidelines for water reuse Reuse Category and Description Treatment

Reclaimed Water Quality

2

Reclaimed Water Monitoring

Setback Distances

3

Comments

Indirect Potable Reuse

Groundwater Recharge by Spreading into Potable Aquifers

Groundwater Recharge by Injection into Potable Aquifers

Augmentation of Surface Water Supply Reservoirs

   

   

   

Secondary (4) Filtration (5) Disinfection (6) Soil aquifer treatment

Secondary (4) Filtration (5) Disinfection (6) Advanced wastewater treatment (16)

Secondary (4) Filtration (5) Disinfection (6) Advanced wastewater treatment (16)

Includes, but not limited to, the following:  No detectable total coliform/100 ml (9, 10)

• 1 mg/l Cl2 residual (min.) (11)

   

pH = 6.5 – 8.5 ≤ 2 NTU (8) ≤ 2 mg/l TOC of wastewater origin Meet drinking water standards after percolation through vadose zone

Includes, but not limited to, the following:  No detectable total coliform/100 ml (9, 10)  1 mg/l Cl2 residual (min.) (11)  pH = 6.5 – 8.5  ≤ 2 NTU (8)  ≤ 2 mg/l TOC of wastewater origin  Meet drinking water standards Includes, but not limited to, the following:  No detectable total coliform/100 ml (9, 10)  1 mg/l Cl2 residual (min.) (11)  pH = 6.5 – 8.5  ≤ 2 NTU (8)  ≤ 2 mg/l TOC of wastewater origin  Meet drinking water standards

Includes, but not limited to, the following:  pH – daily  Total coliform – daily  Cl2 residual – continuous  Drinking water standards – quarterly  Other (17) – depends on constituent  TOC – weekly  Turbidity – continuous  Monitoring is not required for viruses and parasites: their removal rates are prescribed by treatment requirements

Includes, but not limited to, the following:  pH – daily  Turbidity – continuous  Total coliform – daily  Cl2 residual – continuous  TOC – weekly  Drinking water standards – quarterly  Other (17) – depends on constituent  Monitoring is not required for viruses and parasites: their removal rates are prescribed by treatment requirements

 Distance to nearest potable water extraction well that provides a minimum of 2 months retention time in the underground.

 Distance to nearest potable water extraction well that provides a minimum of 2 months retention time in the underground.

 Site specific – based on providing 2 months retention time between introduction of reclaimed water into a raw water supply reservoir and the intake to a potable water treatment plant.

 Depth to groundwater (i.e., thickness to the vadose zone) should be at least 6 feet (2m) at the maximum groundwater mounding point.  The reclaimed water should be retained underground for at least 2 months prior to withdrawal.  Recommended treatment is site-specific and depends on factors such as type of soil, percolation rate, thickness of vadose zone, native groundwater quality, and dilution.  Monitoring wells are necessary to detect the influence of the recharge operation on the groundwater.  Reclaimed water should not contain measurable levels of pathogens after percolation through the vadose zone.(12)  See Section 3.4.3 in the 2004 Guidelines for recommended treatment reliability requirements.  Recommended log-reductions of viruses, Giardia, and Cryptosporidium can be based on challenge tests or the sum of log-removal credits allowed for individual treatment processes. Monitoring for these pathogens is not required.  Dilution of reclaimed water with waters of non-wastewater origin can be used to help meet the suggested TOC limit. The reclaimed water should be retained underground for at least 2 months prior to withdrawal. Monitoring wells are necessary to detect the influence of the recharge operation on the groundwater. Recommended quality limits should be met at the point of injection. The reclaimed water should not contain measurable levels of pathogens at the point of injection. Higher chlorine residual and/or a longer contact time may be necessary to assure virus inactivation. See Section 3.4.3 in the 2004 Guidelines for recommended treatment reliability requirements. Recommended log-reductions of viruses, Giardia, and Cryptosporidium can be based on challenge tests or the sum of log-removal credits allowed for individual treatment processes. Monitoring for these pathogens is not required.  Dilution of reclaimed water with waters of non-wastewater origin can be used to help meet the suggested TOC limit.       

 The reclaimed water should not contain measurable levels of pathogens. (12)  Recommended level of treatment is site-specific and depends on factor such as receiving water quality, time and distance to point of withdrawal, dilution and subsequent treatment prior to distribution for potable uses.  Higher chlorine residual and/or a longer contact time may be necessary to assure virus and protozoa inactivation.  See Section 3.4.3 in the 2004 Guidelines for recommended treatment reliability requirements.  Recommended log-reductions of viruses, Giardia, and Cryptosporidium can be based on challenge tests or the sum of log-removal credits allowed for individual treatment processes. Monitoring for these pathogens is not required.  Dilution of reclaimed water with water of non-wastewater origin can be used to help meet the suggested TOC limit.

Footnotes (1) These guidelines are based on water reclamation and reuse practices in the U.S., and are specifically directed at states that have not developed their own regulations or guidelines. While the guidelines should be useful in may areas outside the U.S., local conditions may limit the applicability of the guidelines in some countries (see Chapter 9). It is explicitly stated that the direct application of these suggested guidelines will not be used by USAID as strict criteria for funding. (2) Unless otherwise noted, recommended quality limits apply to the reclaimed water at the point of discharge from the treatment facility. (3) Setback distances are recommended to protect potable water supply sources from contamination and to protect humans from unreasonable health risks due to exposure to reclaimed water. (4) Secondary treatment process include activated sludge processes, trickling filters, rotating biological contractors, and may stabilization pond systems. Secondary treatment should produce effluent in which both the BOD and SS do not exceed 30 mg/l. (5) Filtration means; the passing of wastewater through natural undisturbed soils or filter media such as sand and/or anthracite; or the passing of wastewater through microfilters or other membrane processes. (6) Disinfection means the destruction, inactivation, or removal of pathogenic microorganisms by chemical, physical, or biological means. Disinfection may be accomplished by chlorination, ozonation, other chemical disinfectants, UV, membrane processes, or other processes. (7) As determined from the 5-day BOD test. (8) The recommended turbidity should be met prior to disinfection. The average turbidity should be based on a 24-hour time period. The turbidity should not exceed 5 NTU at any time. If SS is used in lieu of turbidity, the average SS should not exceed 5 mg/l. If membranes are used as the filtration process, the turbidity should not exceed 0.2 NTU and the average SS should not exceed 0.5 mg/l. (9) Unless otherwise noted, recommended coliform limits are median values determined from the bacteriological results of the last 7 days for which analyses have been completed. Either the membrane filter or fermentation tube technique may be used. (10) The number of total or fecal coliform organisms (whichever one is recommended for monitoring in the table) should not exceed 14/100 ml in any sample. (11) This recommendation applies only when chlorine is used as the primary disinfectant. The total chlorine residual should be met after a minimum actual modal contact time of at least 90 minutes unless a lesser contact time has been demonstrated to provide indicator organism and pathogen reduction equivalent to those suggested in these guidelines. In no case should the actual contact time be less than 30 minutes. (12) It is advisable to fully characterize the microbiological quality of the reclaimed water prior to implementation of a reuse program. (13) The number of fecal coliform organisms should not exceed 800/100 ml in any sample. (14) Some stabilization pond systems may be able to meet this coliform limit without disinfection. (15) Commercially processed food crops are those that, prior to sale to the public or others, have undergone chemical or physical processing sufficient to destroy pathogens. (16) Advanced wastewater treatment processes include chemical clarification, carbon adsorption, reverse osmosis and other membrane processes, advanced oxidation, air stripping, ultrafiltration, and ion exchange. (17) Monitoring should include inorganic and organic compounds, or classes of compounds, that are known or suspected to be toxic, carcinogenic, teratogenic, or mutagenic and are not included in the drinking water standards. (18) See Section 4.4.3.7 for additional precautions that can be taken when a setback distance of 100 ft (30 m) to potable water supply wells in porous media is not feasible.

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse

The suggested regulatory guidelines presented in Table 4-4 are essentially those contained in the 2004 guidelines (EPA, 2004), with some minor modifications that include the following:

3. There have been minor changes to the names of the reuse categories as follows: a. “Urban reuse” is now “Urban Reuse – Unrestricted”

1. Two categories of agricultural reuse (non-food crops and commercially processed food crops) have been combined because the reuse water quality and monitoring recommendations include identical criteria.

b. “”Restricted access irrigation” is now “Urban Reuse – Restricted” c.

2. Information included for IPR guidelines have changed and include changes to TOC and TOX monitoring requirements. The minimum recommended guideline for TOC monitoring has been reduced from 3 mg/L to 2 mg/L. Measurement of TOC in reclaimed water is a gross measure of the organic constituents of wastewater origin; due to increasing interest in addressing trace organic compounds in reclaimed water for potable reuses, the minimum recommended TOC has been modified. This is consistent with the move toward using reduced TOC concentrations for monitoring in the new California draft groundwater replenishment regulations (CDPH, 2011), which would require TOC concentrations less than 0.5 mg/L. However, due to the limit of quantitation for analytical instrumentation commonly used for TOC measurements, these guidelines provide a recommendation of 2.0 mg/L, which is more conservative than the 2004 guidelines. Because the guidelines already provide recommendations that reclaimed water for IPR uses meet drinking water standards, TOX has been removed. TOX is a gross measurement of halogenated compounds, intended to be an indicator disinfection by-products formed during chlorine disinfection. Primary drinking water standards already include a comprehensive list of halogenated organic compounds. While the list is certainly not comprehensive, it provides a good indication of the presence of disinfection byproducts. TOX measurements can have a high level of variability and without additional information on specific compounds does not provide additional information over that provided by TOC and total residual chlorine data.

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“Recreational impoundments” “Impoundments – Unrestricted”

d. “Landscape impoundments” “Impoundments – Restricted”

is

now

is

now

4.4.3.1 Combining Treatment Process Requirements with Water Quality Limits The combination of both treatment process requirements and water quality limits are recommended for the following reasons: 

Water quality criteria that include the use of surrogate parameters may not adequately characterize reclaimed water quality.



A combination of treatment and quality requirements known to produce reclaimed water of acceptable quality obviates the need to routinely monitor the finished water for certain constituents, e.g., some health-significant chemical constituents or pathogenic microorganisms.



Monitoring of real-time surrogates of key treatment processes for their performance now allows assurances of removal of pathogens. (While new methods are emerging for monitoring of pathogenic microorganisms and chemical constituents that can produce information that may be valuable to the public, routine monitoring is not recommended at this time.)



Treatment reliability is enhanced.

4.4.3.2 Water Quality Requirements for Disinfection The guidelines suggest that, regardless of the type of reclaimed water use, some level of disinfection should be provided to avoid adverse health consequences from inadvertent contact or accidental or intentional misuse of a water reuse system. For nonpotable uses of reclaimed water, two disinfection threshold levels are recommended, depending on the probability of

2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

human contact. Reclaimed water used for applications where no direct public or worker contact with the water is expected should be disinfected to achieve an average fecal coliform concentration not exceeding 200/100 mL because, at this indicator bacteria concentration: 

Most pathogens will be reduced to low levels



Disinfection of secondary effluent to this coliform level is readily achievable at minimal cost



Disinfection to lower levels may not further decrease human health risk, because there is no direct contact with the reclaimed water

For uses where direct or indirect contact with reclaimed water is likely or expected, and for dual water systems where there is a potential for crossconnections with potable water lines, disinfection to produce reclaimed water with no detectable fecal coliform organisms per 100 mL is recommended as a minimum treatment goal. In order to meet this disinfection objective, filtration is generally required. Treatment performance has been shown to produce reclaimed water that is essentially free of measurable levels of bacterial and viral pathogens in volumes of about 10 to 100 L using current culture methods. For indirect potable uses of reclaimed water, where reclaimed water is intentionally introduced into the raw water supply for the purposes of increasing the total volume of water available for potable use, disinfection to produce reclaimed water having no detectable total coliform organisms per 100 mL is recommended. Total coliform is recommended, in lieu of fecal coliform, to be consistent with the SDWA National Primary Drinking Water Regulations (NPDWR) that regulate drinking water standards for producing potable drinking water.

analysis includes enumeration of organisms of both fecal and nonfecal origin, while the fecal coliform analysis is specific for coliform organisms of fecal origin. Therefore, fecal coliforms are better indicators of fecal contamination than total coliforms, and these suggested guidelines use fecal coliform as the indicator organism. Either the multiple-tube fermentation technique or the membrane filter technique may be used to quantify the coliform levels in the reclaimed water. Due to the limitations of the total and fecal bacteria indicators, significant research has gone into determining better indicator species. Alternative indicator organisms that may be adopted in the future for water quality monitoring include Enterococci (a genus of bacteria capable of forming spores); Bacteroides (fecal bacteria that have a high degree of host specificity and low potential to proliferate in the environment, allowing for source tracking of fecal contamination); and new choices of bacteriophages (viruses that infect bacteria). These guidelines do not include suggested specific parasite or virus limits. There has been considerable interest in recent years regarding the occurrence and significance of Giardia and Cryptosporidium in reclaimed water (Huffman et al., 2006). However, parasite levels, where they have been monitored for at water reuse operations in the United States, and at the treatment and quality limits recommended in these guidelines have been deemed acceptable (e.g., Florida). Viruses are of concern in reclaimed water, but virus limits are not recommended in these guidelines for the following reasons: 

A significant body of information exists indicating that the enteroviruses are reduced or inactivated to low or non-culturable levels in about 10 to 100 L via appropriate wastewater treatment with disinfection. Adenoviruses, however, are beginning to receive some attention, as they are resistant to UV disinfection.



The identification and enumeration of viruses in wastewater are hampered by relatively low virus recovery rates, the complexity and high cost of current cell culture laboratory procedures, and the limited number of facilities having the personnel and equipment necessary to perform the analyses.

4.4.3.3 Indicators of Disinfection It would be impractical to routinely monitor reclaimed water for all of the chemical constituents and pathogenic organisms of concern, and surrogate parameters are universally accepted. In the United States, total and fecal coliforms are the most commonly used indicator organisms in reclaimed water as a measure of disinfection efficiency. While coliforms are used as indicator organisms for many bacterial pathogens, they are, by themselves, poor indicators of parasites and viruses. The total coliform

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse





The laboratory culturing procedures to determine the presence or absence of pathogenic viruses in a water sample takes about 14 days, and an additional 14 days are required to indentify the viruses. In addition, some enteric viruses do not have permissive cell cultures and therefore cannot be monitored using cell culture techniques. Molecular and genomic technology is providing new tools to rapidly detect and quantify viruses in water (e.g., nucleic acid probes and polymerase chain reaction technology), including viruses that are non-culturable. However, molecular and genomic methods currently in use are not able to differentiate between infective and non-infective virus particles. Therefore, these methods are useful in examining physical removal (by filtration, including membranes) but currently cannot fully determine degree of inactivation through disinfection steps. Methods that combine cell culture with molecular and genomic techniques may be able to improve quantification, while also giving an indication of infectivity.



The value of bacteriophages as indicators for pathogenic viruses is currently an area of debate and ongoing research.



There have been no documented cases based on limited epidemiological studies of viral disease resulting from water reuse operations in the United States.

4.4.3.4 Water Quality Requirements for Suspended and Particulate Matter The removal of suspended matter is related to virus removal. Many pathogens are particulate-associated, and that particulate matter can shield both bacteria and viruses from disinfectants such as chlorine and UV. Also, organic matter consumes chlorine, thus making less of the disinfectant available for disinfection. There is general agreement that particulate matter should be reduced to low levels, e.g., 2 NTU or 5 mg/L total suspended solids (TSS), prior to disinfection to ensure reliable destruction of pathogenic microorganisms during the disinfection process. TSS limits are suggested as a measure of organic and inorganic particulate matter in reclaimed water that has received secondary treatment. Suspended solids measurements are typically performed daily on a composite sample and only 4-14

reflect an average value. Continuously monitored turbidity is superior to daily suspended solids measurements as it provides immediate results that can be used to adjust treatment operations.

4.4.3.5 Water Quality Requirements for Organic Matter The need to remove suspended organic matter is related to the type of reuse. Some of the adverse effects associated with organic substances are that they are aesthetically displeasing (may be malodorous and impart color), provide food for microorganisms, adversely affect disinfection processes, and consume oxygen. The recommended BOD limit is intended to indicate that the organic matter has been stabilized, is non-putrescible, and has been lowered to levels commensurate with anticipated types of reuse. The recommended BOD and TSS limits are readily achievable at well-operated water reclamation plants.

4.4.3.6 Setback Distances Many states have established setback distances or buffer zones between wastewater outfalls, reuse irrigation sites, and various facilities such as potable water supply wells, drinking fountains, property lines, residential areas, and roadways. Requirements for setback distances vary depending on the quality of reclaimed water introduced to the environment, and the method of application. Although the suggested setback distances are somewhat subjective, they are intended to protect drinking water supplies from contamination and, where appropriate, to protect humans from exposure to the reclaimed water. In irrigation, the general practice is to limit, through design or operational controls, exposure to aerosols and windblown spray produced from reclaimed water that is not, or only minimally, disinfected. Setback distances from potable wells are intended to maintain a zone immediately around a well that is not subject to irrigation. Overall the imperative is to control sources of reuse water and its possible contaminant content, and minimize infiltration (movement of water from the surface into the soil), and any vertical or horizontal component of transport of potential contaminants through the subsurface soils. Once the water has infiltrated into the soil formation, the zone of saturation may also encounter zones of preferential flow that can lead to more rapid transport of any contaminant or solute. In media that has highlyvariable porosity or transmissivity (e.g., sensitive

2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

hydrogeological areas such as karst or fractured bedrock), the ground water residence time is often too uncertain to be useful; or protective. Overall a larger setback distance should be considered in porous soils compared to lower permeability soils. This is because most soils are not well-classified or mapped. In the absence of such information (usually gleaned from geotechnical evaluations), a more conservative setback distance is recommended. These setback distances are often applied also to physical separation between the well and any other nonpotable source in another buried conveyance, such as sewer pipes. In addition, most states also have parallel drinking water regulations for well-head protection that identify separation distances from various operations that may introduce water into or onto sensitive areas. Where these separation distances are not achievable, designers/regulators should consider additional precautions (e.g., use area controls or design components) to maintain an adequate margin of public health protection through the potable water system. The recommended setback distances outlined in Table 4-4 are greater for the Restricted Urban category than the Unrestricted Urban category and greater for the Agricultural Reuse for Processed Food Crops and Non-Food Crops category than for the Agricultural Reuse for Food Crop category. These increased recommended setback distances are to maintain protection of public health, given that the suggested level of treatment and resulting water quality are less stringent than for Unrestricted Urban reuse or Agricultural Reuse for Food Crops.

4.4.3.7 Specific Considerations for IPR Only a limited number of states have IPR reuse regulations, some of which are implemented through groundwater recharge rules. In states where IPR regulations or guidelines exist, these include requirements for treatment processes and reclaimed water quality and monitoring. States may specify the requirement of a pretreatment program, pilot plant studies, and public hearings. Water quality requirements for IPR typically include limits for TSS, nitrogen, TOC, turbidity, and total coliform. California draft IPR regulations also require limits for specific organics and design requirements for pathogen removal. Most states also specify a minimum time the reclaimed water must be retained in an environmental buffer (e.g., bioretention cells, properly-designed rain gardens, etc.) prior to being withdrawn as a source of

2012 Guidelines for Water Reuse

drinking water, or the separation distance between a point of recharge and a point of withdrawal. As noted in Table 4-4, it is appropriate to consider increasing the separation distance when the project is located in porous soils. In this context, the definition of porous media includes soils that are sandy (sand, sandy loam, sandy clay loam, loam), gravels, or interbedding thereof; soil formations wherein clay lenses are not predominant. Other sources of high-transmissivity may be found in rural or urban areas, and call for special consideration of well fields that border construction landfills (where buried construction debris can exhibit high transmissivity), and vacant lots. In addition to IPR regulations, drinking water standards also apply to public water supplies, since the reclaimed water will be processed through a drinking water treatment plant prior to potable reuse. As needs for alternative water supplies grow, reclaimed water is anticipated to be intentionally used more in potable supply applications, and while no illnesses have been directly connected to the use of properly treated and managed reclaimed water, it is well recognized that the understanding of the risks from constituents of emerging concern is a rapidly evolving field, and that regulatory requirements need to be based on best available science. By example, in California, the SWRCB included a provision in their Recycled Water Policy to establish a Science Advisory Panel to provide guidance for developing monitoring programs that assess potential threats from chemicals of emerging concern (CECs) and pathogens in landscape irrigation and IPR applications. The Science Advisory Panel’s study made the following conclusion about pathogen monitoring in irrigation and IPR: “Given the multiple barrier concept and water treatment process redundancy requirements in place, the Panel believes that the potential public health risk associated with exposure to pathogens in recycled water used for landscape irrigation or groundwater recharge is very small. However, the Panel acknowledges that some uncertainties exist regarding the occurrence of emerging waterborne microbial pathogens and encourages additional research into their fate in water reuse systems.” (Anderson et al., 2010)

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Chapter 4 | State Regulatory Programs for Water Reuse

Regarding CECs, the panel provided a conceptual framework for determining which CECs should be monitored out of thousands of potential targets and applied the framework to identify a list of chemicals that should be monitored presently, as described in Chapter 6 (Anderson et al., 2010). The Panel also urged California to reapply this prioritization process on at least a triennial basis and establish a state independent review panel that can provide a periodic review to the CEC monitoring efforts. The most recent draft regulations for Groundwater Replenishment Reuse in California would require annual monitoring of an indicator compound with the ability to characterize the presence of pharmaceuticals, endocrine disrupting chemicals, personal care products, and other indicators of the presence of municipal wastewater (CDPH, 2011). In general, as states adopt or update guidelines and regulations for water reuse, an adaptive, risk-based approach to addressing reclaimed water quality monitoring is appropriate (NRC, 2012). When considering projects that may impact potable aquifers, use of multiple barriers is prudent and designers and regulators may consider the incorporation of additional precautions for public health protection, including: 

Multiple, independent barriers for removing and or transforming microbiological and chemical contaminants. Some emphasis should be placed on gaining a better understanding of soils via focused geotechnical site investigation or review of geotechnical reports for the area of interest.



Advanced technologies that address a broader variety of contaminants with greater reliability;



An operational plan with documented retention time and its effectiveness in attenuation of contaminants for a given barrier measure; and a monitoring program tailored to specific barriers and local conditions with appropriate systems to respond to potential system malfunctions.

4.4.4 Additional Requirements In addition to reclaimed water quality and treatment requirements, states also adopt requirements governing monitoring, reliability, storage, and irrigation application rates. Appendix A of the 2004 guidelines illustrates the difference in state requirements for many of these requirements (EPA, 2004). However, as

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these requirements are often updated, refer to the state regulatory websites contained in Appendix C for the most current state rules, regulations or guidelines related to water reuse.

4.4.4.1 Reclaimed Water Monitoring Requirements Water quality monitoring is an important component of reclaimed water projects to ensure that public health and the environment are protected. Monitoring requirements vary greatly from state to state and again depend on the type of reuse. Typical monitoring programs focus on parameters with numeric water reuse criteria, including many of those included in Table 4-4, such as BOD, TSS, turbidity, and pathogens or pathogen indicators. Depending on the project and state permitting procedures, monitoring can also include parameters such as salts, minerals, and constituents with MCLs, to determine if the designated uses of receiving waters, both groundwater and surface water, are being protected. Real-time online process monitoring of surrogate parameters is sometimes specified. Typically, reclaimed water monitoring requirements specify that monitoring be conducted at the water reclamation plant before reclaimed water is distributed for use. However, several states specifically require monitoring of groundwater where reclaimed water is used for irrigation. For groundwater recharge projects, including those to provide saltwater intrusion barriers, monitoring may be required using lysimeters, monitoring wells, or groundwater production wells. For reservoir augmentation projects, monitoring may be required for surface water and treated drinking water. For IPR projects, additional monitoring locations may be required (Crook, 2010).

4.4.4.2 Treatment Facility Reliability Some states have adopted facility reliability regulations or guidelines in place of, or in addition to, water quality requirements. Generally, these requirements consist of alarms warning of power failure or failure of essential unit processes, automatic standby power sources, emergency storage, and the provision that each treatment process be equipped with multiple units or a back-up unit. These processes are described in Section 2.3.4. Section 4 of the 2004 guidelines describes some of the regulatory approaches with respect to reliability, which generally include

2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

specifications for engineered redundancy, system capacity, and backup systems (EPA, 2004).

4.4.4.3 Reclaimed Water Storage Storage is discussed in Chapter 2. Current regulations and guidelines regarding storage requirements are primarily based upon the need to limit or prevent surface water discharge and are not related to storage required to meet diurnal or seasonal variations in supply and demand for water reuse. Reclaimed water storage requirements vary from state to state and are generally dependent on geographic location, site conditions, and the existence of alternative disposal options. A comparison of regulatory approaches to storage is included in Section 4 of the 2004 guidelines (EPA, 2004).

4.5 Inventory of State Regulations and Guidelines

A survey was conducted to inventory the reuse regulations and guidelines promulgated by U.S. states, tribal communities, and territories for this document. Regulatory agencies in all 50 states and the District of Columbia were contacted to obtain information concerning their current regulations or guidelines governing water reuse. EPA’s liaison offices for tribal communities, Guam, Puerto Rico, the U.S. Virgin Islands, American Samoa, and Commonwealth of the Northern Mariana Islands were likewise contacted.

4.5.1 Overall Summary of States’ Regulations Table 4-5 provides a summary of the current regulations and guidelines governing water reuse by state and by reuse category. The table identifies those states that have regulations, those with guidelines and those states that currently do not have either. The table also distinguishes between states where the intent of the regulations or guidelines is oversight of water reuse from states where the intent of the regulations or guidelines is to facilitate disposal and water reuse is considered incidental. This distinction of intent among states’ regulations and guidelines can be quite subjective and open to interpretation, but is provided here to capture some of the nuance in interpreting a state’s regulatory context.

Territory, have regulations and four have guidelines that implicate water reuse primarily from a disposal perspective. Lastly, 27 states have undergone or just completed revisions to their current reuse regulations or guidelines as shown in Table 4-5. To date, no states have developed or proposed regulations or guidelines specifically governing DPR. However, some states may issue project-specific permits for this reuse with detailed treatment, reclaimed water quality and monitoring requirements. DPR is discussed further in Chapter 3. A table with links to state regulatory websites is provided in Appendix C. The WateReuse Association will maintain links of the state regulatory sites containing water reuse regulations as links and current regulations are subject to change by the states. Readers may access the state regulations link at .

4.5.1.1. Case-By-Case Considerations In states with no specific regulations or guidelines for water reclamation and reuse, projects may still be permitted on a case-by-case basis, such as in Connecticut and Wisconsin. Likewise, some states that do have rules enable consideration of reuse options that are not specifically addressed within their existing rules or regulations. For example, Florida’s rules and Virginia’s regulations governing water reuse enable these states to permit other uses if the applicant demonstrates that public health will be protected. Several other activities (including use in laundries, vehicle washing, mixing of concrete, and making ice for ice rinks) are specifically identified as being allowable within Florida’s reuse rules.

As of August 2012, 22 states have adopted regulations and 11 states have guidelines or design standards with water reuse as the primary intent. Additionally, eight states and CNMI, a U.S. Pacific Insular Area

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse

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2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse

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 





(1) (2) (3) (4)

Specific regulations or guidelines on reuse not adopted; however, reuse may be approved on a case-by-case basis The state had guidelines prior, and now has adopted regulations. CNMI regulations were not listed in the 2004 guidelines. Guam has regulations pertaining to Urban Restricted Reuse and Indirect Potable Reuse but they are not regulated by reuse or disposal regulations. (5) Minnesota has been using the California rules as their Municipal Wastewater Reuse guidance since the mid 90’s. This was not reflected in the 2004 guidelines, which indicated that Minnesota had no guidance. (6) Montana is in the midst of promulgating new reuse regulations, which are anticipated to be finalized by the time of this publication. (7) The state had guidelines prior, and now has adopted reuse regulations as well as guidelines. (8) Reclaimed water projects in New Mexico are permitted under either a Ground Water Discharge Permit (which also controls use above ground) or a Construction Industries Permit if use in a building is included. (9) Current interpretation is that New York has no regulations or guidelines. (10) Groundwater recharge was added to Oregon’s reuse regulations in 2008. (11) The state previously had no guidelines or regulations and has adopted guidelines. (12) Tennessee was listed as having regulations in the 2004 Guidelines; however, these were later deemed to be guidelines not regulations. (13) The state previously had no guidelines or regulations and has adopted regulations. (14) The Washington State currently has no regulations governing the use of reclaimed water. Draft regulations have been developed by the Department of Ecology in coordination with Department of Health and formal rules advisory committee. The draft rules are incomplete. Adoption of the rules has been delayed until after June 30, 2013. The reclaimed water use statute and formal standards, guidance and procedures adopted in 1997 remain in effect. (15) In the 2004 guidelines West Virginia was listed as having regulations; however, these appear to be wastewater treatment regulations and do not specifically govern reuse. * No information is available at this time on regulations or guidelines on water reuse promulgated by federally recognized tribal nations, Puerto Rico, the U.S. Virgin Islands, and American Samoa.

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2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

Four case studies specifically focus on policy and regulatory processes in states around the U.S. Arizona [US-AZ-Blue Ribbon Panel] This case study describes the special Blue Ribbon Panel on Water Sustainability (BRP) formed by the Governor of Arizona in 2009. The BRP’s charge was to focus on water conservation and recycling as strategies to improve water sustainability in Arizona. The BRP was jointly chaired by officials from the ADEQ, Arizona Department of Water Resources (ADWR) and Arizona Corporation Commission (ACC), Arizona’s constitutionally established regulatory body for privately owned utilities. The case study describes the participatory process the BRP went through and some of the key recommendations. California [US-CA-Regulations] This case study chronicles the evolution of water reuse laws in California, from the first water quality guidance for the use of raw or settled sewage for agricultural irrigation as far back as 1906 through the 2011 draft regulations for IPR. Virginia [US-VA-Regulations] Virginia recently completed the process of creating a water reuse regulation and adopted the Virginia Water Reclamation and Reuse Regulation in 2008. This case study describes the multiple state agencies that play a role in regulating water reuse in Virginia and the unique aspects of water reuse in the state. Washington [US-WA-Regulations] Washington State has a reclaimed water program governed by comprehensive guidelines that define water quality standards and a variety of allowed beneficial uses. This case study describes how the State Departments of Ecology and Health jointly administer the reclaimed water program and the process since 2006 to develop regulations.

2012 Guidelines for Water Reuse

4.5.1.2 Reuse or Treatment and Disposal Perspective The underlying objectives of regulations and guidelines vary considerably from state to state. States such as Arizona, California, Colorado, Florida, Georgia, Hawaii, Massachusetts, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, Texas, Utah, Virginia, Washington, and Wyoming have developed regulations or guidelines and standards that strongly encourage water reuse as a water resources conservation strategy. These states have developed comprehensive regulations or guidelines specifying water quality requirements, treatment processes, or both, for the full spectrum of reuse applications. The objective in these states is to derive the maximum resource benefits of the reclaimed water while protecting the environment and public health. Other states have regulations or guidelines that focus on land treatment of wastewater-derived effluent, emphasizing additional treatment or effluent disposal rather than reuse, even though the effluent may be used for irrigation of agricultural sites, golf courses, or public access lands. When regulations specify application or hydraulic loading rates, the regulations generally pertain to land application systems that are used primarily for additional wastewater treatment for disposal rather than reuse. When systems are developed chiefly for the purpose of land treatment or disposal, the objective is often to dispose of as much effluent on as little land as possible; thus, application rates are often far greater than irrigation demands and limits are set for the maximum hydraulic loading. On the other hand, when the reclaimed water is managed as a valuable resource, the objective is to apply the water according to irrigation needs rather than maximum hydraulic loading, and application limits are rarely specified. Optimal irrigation application rates are based on site conditions (FAO, 1985). There are many differences in the definition and approach to water reuse between states. Due to these differences, the same practice that may be considered reuse in one state may be considered primarily a means of disposal or additional “land treatment” in another. The primary reuse of reclaimed wastewater in South Dakota is by land application to non-food crops. Although South Dakota has some guidelines on land application to food crops, no one is currently doing this. South Dakota also has a few facilities that are

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Chapter 4 | State Regulatory Programs for Water Reuse

using infiltration or evaporation/ percolation basins as a component of their wastewater treatment facility, rather than a disposal activity. Nevada reports similar use of percolation basins as a disposal activity. Florida, however, would consider this activity reuse by surficial groundwater recharge if the percolation basins were allowed to be loaded and rested alternately. In most states, the release of reclaimed water to a stream or other water body is still considered and permitted as a point source discharge despite the fact that it may create, enhance or sustain the water bodies receiving that water. In Texas, reuse for stream environmental enhancement or recreational reuse requires a discharge permit if the supplemental discharge point for these reuses will be at a location different from that of the primary discharge location of the treatment facility. For example, SAWS has a discharge permit for the Dos Rios Water Reclamation Facility (into the confluence of the San Antonio and Medina Rivers), one permitted discharge upstream in Salado Creek to maintain creek water quality, and three permitted discharge points into the San Antonio River to maintain flow and water quality in the San Antonio River through the River Walk entertainment area.

4.5.2 Summary of Ten States’ Reclaimed Water Quality and Treatment Requirements Reclaimed water quality and treatment requirements are a significant part of each state’s regulations and guidelines for water reuse and may vary among the different reuse categories listed in Table 4-5 above. Generally, where water reuse involves unrestricted public exposure, reclaimed water must be more highly treated for the protection of public health. Where public exposure is not likely, however, a lower level of treatment is usually acceptable. Many states include design requirements based on a certain removal of bacterial, viral, or protozoa pathogens for public health protection. Total and fecal coliform counts are generally used as indicator organisms for many bacterial pathogens and provide a measure of disinfection process efficacy. Monitoring of viral indicators is generally not required, though virus removal rates are often prescribed by treatment requirements for system design. A limit on turbidity is usually specified as a real-time monitoring tool to verify the performance of filtration in advanced treatment

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facilities. The performance of disinfection processes is monitored in real time using chlorine residual or UV intensity, depending on the disinfection method. Disinfection is also verified using bacteria cell culture methods. In addition, water quality limits are generally imposed for BOD and TSS. Water quality parameters are discussed in greater detail in Chapter 6 and monitoring protocols are discussed in Chapter 2. A summary of the reclaimed water quality and treatment requirements follows of the following 10 states: Arizona, California, Florida, Hawaii, Nevada, New Jersey, North Carolina, Texas, Virginia, and Washington. These states’ regulations and guidelines were chosen because these states provide a collective wisdom of successful reuse programs and, in most cases, long-term experience. In addition to water quality and treatment requirements, states provide requirements or guidance on a wide range of other aspects of reuse, such as but not limited to, monitoring, reliability, storage, loading rates, and setback distances. For additional details of state regulations, readers are referred to the state regulatory websites contained in Appendix C of this document. The following sections generally describe reuse categories that were presented in Table 4-3. It is of note that the 10 states, discussed herein, have all established types or levels of reclaimed water based on water quality. States including North Carolina, Virginia, and Texas have established only two types of reclaimed water, while others like Arizona and Washington have a greater number of categories. In any case, the regulatory framework has been established to ensure that the water quality is appropriate for the end use. Information for these 10 representative states is presented in Tables 4-7 through 4-16. The reclaimed water quality type or level that applies to the specific reuse category is noted, where applicable, in the header of the table. Additional details on each of the states' reclaimed water types and quality can be found in the links provided in Appendix C. As a matter of brevity for tabular presentation of information, several abbreviations have been used throughout the tables as noted in Table 4-6.

2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-6 Abbreviations of terms for state reuse rules descriptions Term Annual Average Corrective action threshold Day Geometric mean Hour Maximum Median Minimum Month UV dose requirements including: 2 • 100 mJ/cm for media filtration 2 • 80 mJ/cm for membrane filtration 2 • 50 mJ/cm for RO treatment There are additional requirements for bioassay validation and UV system design considerations Product of the total residual chlorine and contact time Total residual chlorine Week Year

Abbreviation ann avg CAT d geom hr max med min mon

NWRI UV Guidelines*

CrT** TRC wk yr

* Most states reference either the 2000, 2003, or 2012 NWRI Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse (NWRI, 2000; NWRI, 2003; NWRI, 2012). A description of the updates to the 2012 NWRI guidelines is provided in Section 6.4.3.2. ** Also abbreviated as CT.

In addition, where TRC is listed in the tables, it is measured after the indicated contact time.

4.5.2.1 Urban Reuse – Unrestricted Unrestricted urban reuse involves the use of reclaimed water where public exposure is likely in the reuse application, thereby requiring a high degree of treatment. In general, all states that specify a treatment process require a minimum of secondary treatment and disinfection prior to unrestricted urban reuse. However, the majority of states require additional levels of treatment that may include oxidation, coagulation, and filtration. Texas does not specify the type of treatment processes required but sets limits on the reclaimed water quality. At this time, no states have set limits on specific pathogenic organisms for unrestricted urban reuse. However, Florida does require monitoring of Giardia and Cryptosporidium with sampling frequency based on treatment plant capacity. Table 4-7 shows the

2012 Guidelines for Water Reuse

reclaimed water quality and treatment requirements for unrestricted urban reuse for the selected states.

4.5.2.2 Urban Reuse – Restricted Restricted urban reuse involves the use of reclaimed water where public exposure to the reclaimed water is controlled; therefore, treatment requirements may not be as strict as those for unrestricted urban reuse. Florida imposes the same requirements on both unrestricted and restricted urban access reuse. In general, the states require a minimum of secondary or biological treatment followed by disinfection prior to restricted urban reuse. Florida requires additional levels of treatment with filtration and possibly coagulation prior to restricted urban reuse. As in unrestricted urban reuse, Texas does not specify the type of treatment processes required but sets limits on the reclaimed water quality. At this time, no states have set limits on specific pathogenic organisms for restricted urban reuse. Florida does not require monitoring of Giardia and Cryptosporidium for Restricted Urban Reuse. Table 4-8 shows the reclaimed water quality and treatment requirements for restricted urban reuse.

4.5.2.3 Agricultural Reuse – Food Crops The use of reclaimed water for irrigation of food crops is prohibited in some states, while others allow irrigation of food crops with reclaimed water only if the crop is to be processed and not eaten raw. For example, some of the states that allow for irrigation of food crops, such as Florida, Nevada, and Virginia, require that the reclaimed water does not come in contact with the crop to be eaten or that the crop is peeled or thermally process prior to being eaten, with a few exceptions. Nevada allows only surface irrigation of fruit or nut bearing trees. In Florida, direct contact (spray) irrigation of edible crops that will not be peeled, skinned, cooked, or thermally-processed before consumption is not allowed except for tobacco and citrus. Indirect contact methods (ridge and furrow, drip, subsurface application system) can be used on any type of edible crop. However, other states, such as California, do not have this stipulation but have more stringent quality standards at or near potable quality. Depending on the type of crop or type of irrigation, states’ treatment requirements range from secondary treatment and disinfection, to oxidation, coagulation, filtration, and high-level disinfection. North Carolina has specific limits for Clostridium and coliphage for indirect contact irrigation for crops that will not be

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Chapter 4 | State Regulatory Programs for Water Reuse

peeled, skinned, or thermally processed. Florida requires monitoring of Giardia and Cryptosporidium with sampling frequency, reclaimed water quality and treatment requirements as shown in Table 4-9 for irrigation of food crops.

4.5.2.4 Agricultural Reuse – Processed Food Crops and Non-food Crops

specifically pertaining to this category of reuse. Texas does not specify treatment process requirements. The remaining states require secondary treatment with disinfection, with some of the states requiring oxidation and filtration. At this time, no states have set limits on specific pathogenic organisms for restricted impoundments reuse. Table 4-12 shows the reclaimed water quality and treatment requirements for restricted recreational reuse.

The use of reclaimed water for agricultural irrigation of non-food crops or for food crops intended for human consumption that will be commercially processed presents a reduced opportunity of human exposure to the water, resulting in less stringent treatment and water quality requirements than other forms of reuse. However, in cases where milking animals would graze on fodder crops irrigated with reclaimed water, there are additional requirements for waiting periods for grazing and a higher level of disinfection is recommended, if a waiting period is not adhered to. In the majority of the states, secondary treatment followed by disinfection is required. There are several states that do not require disinfection if certain buffer requirements are met. At this time, no states have set limits on specific pathogenic organisms for agricultural reuse on non-food crops. Table 4-10 shows the reclaimed water quality and treatment requirements for irrigation of non-food crops.

Florida, Nevada, North Carolina, and Washington have regulations pertaining to the use of reclaimed water to create, enhance, sustain, or augment wetlands, other aquatic habitats, or streamflows. Florida has comprehensive and complex rules governing the discharge of reclaimed water to wetlands. Treatment and disinfection levels are established for different types of wetlands, different types of uses, and the degree of public access. Most wetland systems in Florida are used for tertiary wastewater treatment, and wetland creation, restoration, and enhancement projects can be considered reuse. Washington also specifies different treatment requirements for different types of wetlands and based on the degree of public access. Table 4-13 shows the reclaimed water quality and treatment requirements for environmental reuse.

4.5.2.5 Impoundments – Unrestricted

4.5.2.8 Industrial Reuse

As with unrestricted urban reuse, unrestricted reuse for impoundments involves the use of reclaimed water where public exposure is likely, thereby requiring a high degree of treatment. Only half of the 10 states (Arizona, California, Nevada, Texas, and Washington) have regulations or guidelines pertaining specifically to unrestricted impoundments. Of these states, only Texas does not specify treatment requirements. It is also of note that neither Arizona nor Nevada allow fullbody contact (e.g., wading) in unrestricted impoundments. Table 4-11 shows reclaimed water quality and treatment requirements for unrestricted impoundments.

4.5.2.6 Impoundments – Restricted State regulations and guidelines regarding treatment and water quality requirements for restricted reuse for impoundments are generally less stringent than for unrestricted reuse for impoundments because the public exposure to the reclaimed water is less likely. Six of the 10 states (Arizona, California, Hawaii, Nevada, Texas, and Washington) have regulations

4-24

4.5.2.7 Environmental Reuse

Eight of the 10 states (California, Florida, Hawaii, Nevada, North Carolina, Texas, Virginia, and Washington) have regulations or guidelines pertaining to industrial reuse of reclaimed water. Arizona and New Jersey review industrial reuse on a case-by-case basis and determine regulations accordingly. Reclaimed water quality and treatment requirements vary based on the final use of the reclaimed water and exposure potential. For example, California has different requirements for the use of reclaimed water as cooling water, based on whether or not a mist is created. In North Carolina, reclaimed water produced by industrial facilities is not required to meet the reuse criteria if the reclaimed water is used in a process that has no public access. Use in toilets and urinals or fire suppression systems will be approved on a case-bycase basis if no risk to public health is demonstrated. Table 4-14 shows the reclaimed water quality and treatment requirements for industrial reuse.

2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

4.5.2.9 Groundwater Recharge – Nonpotable Reuse Spreading basins, percolation ponds, and infiltration basins have a long history of providing both effluent disposal and groundwater recharge. Most state regulations allow for the use of relatively low quality water (i.e., secondary treatment with basic disinfection) based on the fact that these systems have a proven ability to provide additional treatment. Traditionally, potable water supplies have been protected by requiring a minimum separation between the point of application and any potable supply wells. These groundwater systems are also typically located so that their impacts to potable water withdrawal points are minimized. While such groundwater recharge systems may ultimately augment potable aquifers, that is not their primary intent and experience suggests current practices are protective of raw water supplies. California, Florida, Hawaii, and Washington have regulations or guidelines for reuse with the specific intent of groundwater recharge of nonpotable aquifers. Hawaii does not specify required treatment processes, determining requirements on a case-by-case basis. The Hawaii Department of Health Services bases the evaluation on all relevant aspects of each project, including treatment provided, effluent quality and quantity, effluent or application spreading area operation, soil characteristics, hydrogeology, residence time, and distance to withdrawal. Hawaii requires a groundwater monitoring program. Arizona regulates groundwater recharge through their Aquifer Protection Permit process. Washington has extensive guidelines for the use of reclaimed water for direct groundwater recharge of nonpotable aquifers although all aquifers in the state are considered to be potable. Recharge of nonpotable aquifers in Washington first requires the redesignation of the aquifer to nonpotable. Table 4-15 shows reclaimed water quality and treatment requirements for groundwater recharge via rapid-rate (surface spreading) application systems.

4.5.2.10 Indirect Potable Reuse (IPR) IPR involves use of reclaimed water to augment surface or groundwater sources that are used or will be used for public water supplies or to recharge groundwater used as a source of public water supply. Unplanned (de facto) IPR is occurring in many river systems today. Additionally, many types of reuse projects inadvertently contribute to groundwater as an unintended result of the primary activity. For example,

2012 Guidelines for Water Reuse

irrigation can replenish groundwater sources that will eventually be withdrawn for use as a potable water supply. IPR systems, as defined here, are distinguished from typical groundwater recharge systems and surface water discharges by both intent and proximity to subsequent withdrawal points for potable water use. IPR involves intentional introduction of reclaimed water into the raw water supply for the purposes of increasing the volume of water available for potable use. In order to accomplish this objective, the point at which reclaimed water is introduced into the environment must be selected to ensure it will flow to the point of withdrawal. Typically the design of these systems assumes there will be little additional treatment in the environment after discharge, and all applicable water quality requirements are met at the point of release of the reclaimed water. Four of the 10 states (California, Florida, Hawaii, and Washington) have regulations or guidelines specifically pertaining to IPR. For groundwater recharge of potable aquifers, most of the states require a pretreatment program, public hearing requirements prior to project approval, and a groundwater monitoring program. Florida and Washington require pilot plant studies to be performed. In general, all the states that specify treatment processes require secondary treatment with filtration and disinfection. Washington has different requirements for surface percolation, direct groundwater recharge, and streamflow augmentation. Hawaii does not specify the type of treatment processes required, determining requirements on a case-by-case basis. Texas and Virginia do not have specific IPR regulations but review specific projects on a case-by-case basis. Most states specify a minimum time the reclaimed water must be retained underground prior to being withdrawn as a source of drinking water. Several states also specify minimum separation distances between a point of recharge and the point of withdrawal as a source of drinking water. Table 4-16 shows the reclaimed water quality and treatment requirements for IPR.

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Chapter 4 | State Regulatory Programs for Water Reuse

Monitored Reclaimed Water Quality Requirements

Treatment (System Design) Requirements

Table 4-7 Urban reuse – unrestricted

Unit processes

Arizona Class A

California Disinfected Tertiary

Secondary treatment, filtration, disinfection

Oxidized, coagulated, filtered, disinfected

NS

NWRI UV Guidelines

NS

UV dose, if UV disinfection used Chlorine disinfection requirements, if used

Hawaii R1 Water

Nevada Category A

New Jersey Type I RWBR

North Carolina Type 1

Texas Type I

Oxidized, filtered, disinfected

Secondary treatment, disinfection

Filtration, high-level disinfection

Filtration (or equivalent)

NS

NWRI UV Guidelines enforced, variance allowed

NWRI UV Guidelines

NS

100 mJ/cm2 at max day flow

NS

NS

NS

NWRI UV Guidelines

CrT > 450 mg·min/L; 90 minutes modal contact time at peak dry weather flow

TRC > 1 mg/L; 15 minutes contact time at peak hr flow1

Min residual > 5 mg/L; 90 minutes modal contact time

NS

Min residual > 1 mg/L; 15 minutes contact time at peak hr flow

NS

NS

TRC CAT < 1 mg/L; 30 minutes contact time at avg flow or 20 minutes at peak flow

Chlorine residual > 1 mg/L; 30 minutes contact time (CrT > 30 may be required

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

NS

-10 mg/L (mon avg) -15 mg/L (daily max)

5 mg/L

Florida Secondary treatment, filtration, high-level disinfection

Virginia Level 1 Secondary treatment, filtration, high-level disinfection

Washington Class A Oxidized, coagulated, filtered, disinfected

BOD5 (or CBOD5)

NS

NS

CBOD5: -20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

TSS

NS

NS

5 mg/l (max)

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

5 mg/l

-5 mg/l (mon avg) -10 mg/l (daily max)

NS

NS

30 mg/L; this limit is superseded by turbidity

-2 NTU (24-hr avg) -5 NTU (max)

-2 NTU (avg) for media filters -10 NTU (max) for media filters -0.2 NTU (avg) for membrane filters -0.5 NTU (max) for membrane filters

Case-by-case (generally 2 to 2.5 NTU) Florida requires continuous on-line monitoring of turbidity as indicator for TSS

-2 NTU (95-percentile) -0.5 NTU (max)

NS

2 NTU (max) for UV

10 NTU (max)

3 NTU

-2 NTU (daily avg), CAT > 5 NTU

-2 NTU (avg) -5 NTU (max)

Turbidity

Bacterial indicators

Fecal coliform: -none detectable in last 4 of 7 samples -23/100mL (max)

Pathogens

Other

NS

If nitrogen > 10 mg/L, special requirements may be mandated to protect groundwater

Total coliform: -2.2/100mL (7-day med) -23/100mL (not more than one sample exceeds this value in 30 d) -240/100mL (max)

Fecal coliform: -75% of samples below detection -25/100mL (max)

NS

Giardia and Cryptosporidium sampling once each 2-yr period for plants ≥1 mgd; once each 5-yr period for plants ≤ 1 mgd

-

-

Fecal coliform: -2.2/100mL (7-day med) -23/100mL (not more than one sample exceeds this value in 30 d) -200/100mL ( max)

Total coliform: -2.2/100mL (30-d geom) -23/100mL (max)

TR

TR

NS

NS

-

(NH3-N + NO3-N) < 10 mg/L (max)

Ammonia as NH3-N: -4 mg/L (mon avg) -6 mg/L (daily max)

-

Fecal coliform: -2.2/100mL (wk med) -14/100mL (max)

Fecal coliform or E. coli: -14/100mL (mon mean) -25/100mL (max)

10 mg/L (mon avg)

Fecal coliform or E. coli: -20/100mL (30-d geom) -75/100mL (max) Enterococci: -4/100mL (30-d geom) -9/100mL (max)

NS

-

or CBOD5: 8 mg/L (mon avg)

30 mg/L

Fecal coliform: -14/100mL (mon geom), CAT > 49/100mL E. coli: -11/100mL (mon geom), CAT > 35/100mL

Total coliform -2.2/100mL (7-d med) -23/100mL (max)

Enterococci: -11/100mL (mon geom), CAT > 24/100mL

NS

NS

-

Specific reliability or redundancy requirements based on formal reliability assessment

NS = not specified by the state’s reuse regulation; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements 1

In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the concentration of fecal coliform prior to disinfection: is ≤ 1,000 cfu per 100 mL, the CrT shall be 25 mg·min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg·min/L; and is ≥ 10,000 cfu per 100 mL the CrT shall be 120 mg·min/L.

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-8 Urban reuse – restricted California Disinfected Secondary-23

Florida

Secondary treatment, disinfection

Oxidized, disinfected

NS

NS

Treatment (System Design) Requirements

Arizona Class B Unit processes UV dose, if UV disinfection used Chlorine disinfection requirements, if used

Monitored Reclaimed Water Quality Requirements

BOD5 (CBOD for Florida)

NS

NS

2

NS

Nevada Category B

New Jersey Type II RWBR

North Carolina Type 1

NS

Oxidized, disinfected

Secondary treatment, disinfection

Case-by-case

NS

NS

NS

75 mJ/cm2 at max day flow

NS

Chlorine residual > 5 mg/L, actual modal contact time of 10 minutes

NS

Chlorine residual > 1 mg/L; 15 minute contact time at peak hr flow

NS

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

NS

2

Texas Type II

Virginia Level 2

Washington Class C

Filtration (or equivalent)

NS

Secondary treatment, disinfection

Oxidized, disinfected

NS

NS

NS

NWRI UV Guidelines

NS

TRC CAT < 1 mg/L 30 minutes contact time at avg flow or 20 minutes at peak flow

Chlorine residual > 1 mg/L; 30 minutes contact time

NS

-10 mg/L(mon avg) -15 mg/L (daily max)

Without pond system: 20 mg/L (or CBOD 15 mg/L) With pond: 30 mg/L

-30 mg/L (mon avg) -45 mg/L (max wk) or CBOD5 -25 mg/L (mon avg) -40 mg/L (max wk)

30 mg/L

TSS

NS

NS

NS

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

30 mg/L

-5 mg/L (mon avg) -10 mg/L (daily max)

NS

-30 mg/L (mon avg) -45 mg/L (max wk)

30 mg/L

Turbidity

NS

NS

NS

NS

NS

NS

10 NTU (max)

NS

NS

NS

Bacterial indicators

Fecal coliform: -less than 200/100mL in last 4 of 7 samples -800/100mL (max)

If nitrogen > 10 mg/L, special requirements Other may be mandated to protect groundwater NS = not specified by the state reuse regulation 1

NS

Hawaii R2 Water

1

Total coliform: -23/100mL (7-d med) -240/100 (not more than one sample exceeds this value in 30 d)

-

NS

-

Fecal coliform: -23/100mL (7-day med) -200/100mL (not more than one sample exceeds this value in 30 d)

-

Fecal coliform: -2.2/100mL (30-d geom) -23/100mL (max)

-

Fecal coliform: -200/100mL (mon geom) -400/100mL (wk geom)

(NH3-N + NO3-N): < 10 mg/L (max)

Fecal coliform or E. coli: -14/100mL (mon mean) -25/100mL (daily max)

Ammonia as NH3-N: -4 mg/L (mon avg) -6 mg/L (daily max)

Fecal coliform or E. coli: -200/100mL (30-d geom) -800/100mL (max) Enterococci: -35/100mL (30-day geom) -89/100mL (max)

-

Fecal coliform: -200/100mL (mon geom), CAT > 800/100mL E. coli: -126/100mL (mon geom), CAT > 235/100mL

Total coliform: -23/100mL (7-d med) -240/100mL (max)

Enterococci: -35/100mL (mon geom), CAT > 104/100mL -

-

Florida does not specifically include urban reuses in its regulations for restricted public access under F.A.C. 62-610-400; requirements for restricted public access reuse are provided in Agricultural Reuse – Non-food Crops, Table 4-9. There is no expressed designation between unrestricted and restricted urban reuse in North Carolina regulations.

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse

Monitored Reclaimed Water Quality Requirements

Treatment (System Design) Requirements

Table 4-9 Agricultural reuse - food crops

Unit processes UV dose, if UV disinfection used Chlorine disinfection requirements, if used

New Jersey Type III RWBR

North Carolina Processed NOT processed Type 1 Type 2

NP

Filtration, high-level disinfection

Filtration (or equivalent)

Filtration, dual UV/chlorination (or equivalent)

NP

100 mJ/cm2 at max day flow

NS

dual UV/chlorination (or equivalent)

Min residual > 5 mg/L, actual modal contact time of 90 minutes

NP

Min residual > 1 mg/L; 15 minutes contact at peak hr flow

30 mg/L or 60 mg/L depending on design flow

NP

Arizona Class A

California Disinfected Tertiary

Secondary treatment, filtration, disinfection

Oxidized, coagulated, filtered, disinfected

Secondary treatment, filtration, high-level disinfection

Oxidized, filtered, disinfected

NS

NWRI UV Guidelines

NWRI UV Guidelines enforced, variance allowed

NWRI UV Guidelines

NS

CrT > 450 mg·min/L; 90 minutes modal contact time at peak dry weather flow

TRC > 1 mg/L; 15 minutes contact time at peak hr flow2

Florida

1

Hawaii R1 Water

Nevada

1

Texas Type I Reclaimed Water

3

Virginia Level 1

Washington Class A

NS

Secondary treatment, filtration, high-level disinfection

Oxidized, coagulated, filtered, disinfected

NS

NS

NWRI UV Guidelines

NS

dual UV/chlorination (or equivalent)

NS

TRC CAT > 1 mg/L; 30 minutes contact time at avg flow or 20 minutes at peak flow

Chlorine residual > 1; 30 minutes contact time

NS

-10 mg/L (mon avg) -15 mg/L (daily max)

-5 mg/L (mon avg) -10 mg/L (daily max)

5 mg/L

BOD5 (or CBOD5)

NS

NS

CBOD5: -20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

TSS

NS

NS

5 mg/L (max)

30 mg/L or 60 mg/L depending on design flow

NP

5 mg/L

-5 mg/L (mon avg) -10 mg/L (daily max)

-5 mg/L (mon avg) -10 mg/L (daily max)

NS

NS

30 mg/L

-2 NTU (24-hr avg) -5 NTU (max)

-2 NTU (avg) for media filters -10 NTU (max) for media filters -0.2 NTU (avg) for membrane filters -0.5 NTU (max) for membrane filters

Case-by-case (generally 2 to 2.5 NTU) Florida requires continuous on-line monitoring of turbidity as indicator for TSS

-2 NTU (95-percentile) -0.5 NTU (max)

NP

2 NTU (max) for UV

10 NTU (max)

5 NTU (max)

3 NTU

2 NTU (daily avg) CAT > 5 NTU

-2 NTU (avg) -5 NTU (max)

Turbidity

Bacterial indicators

Viral indicators

Pathogens

Other

Fecal coliform: -none detectable in last 4 of 7 samples -23/100mL (max)

NS

NS

If nitrogen > 10 mg/L, special requirements may be mandated to protect groundwater

Total coliform: -2.2/100mL (7-day med) -23/100mL (not more than one sample exceeds this value in 30 d) -240/100mL (max)

Fecal coliform: -75% of samples below detection -25/100mL (max)

NS

NS

-

10 mg/L (mon avg)

Fecal coliform or E. coli: -20/100mL (30-d geom) -75/100mL (max)

or CBOD5 8 mg/L (mon avg)

30 mg/L

Fecal coliform: -14/100mL (mon geom), CAT > 49/100mL

Fecal coliform: -2.2/100mL (7-day med) -23/100mL (not more than one sample exceeds this value in 30 d) -200/100mL (max)

NP

NS

TR

NP

NS

NS

Coliphage: - 5/100mL (mon mean) - 25/100mL (daily max)

NS

NS

NS

Giardia, Cryptosporidium sampling once per 2-yr period for plants ≥ 1 mgd; once per 5-yr period for plants ≤ 1 mgd

-

NP

NS

NS

Clostridium: - 5/100mL (mon mean) - 25/100mL (daily max)

NS

NS

NS

-

Oxidized, filtered, disinfected

Ammonia as NH3-N: -4 mg/L (mon avg) -6 mg/L (daily max)

Ammonia as NH3-N: -1 mg/L (mon avg) -2 mg/L (daily max)

-

Specific reliability and redundancy requirements based on formal assessment

-

Fecal coliform: -2.2/100mL (wk med) -14/100mL (max)

(NH3-N + NO3-N): < 10mg/L (max) Special information, crop tests may be required

Fecal coliform or E. coli: -14/100mL (mon mean) -25/100mL (daily max)

Fecal coliform or E. coli: -3/100mL (mon mean) -25/100mL (mon mean)

Enterococci: -4/100mL (30-d geom) -9/100mL (max)

-

E. coli: -11/100mL (mon geom), CAT > 35/100mL

Total coliform: -2.2/100mL ( 7-d med) -23/100mL (max)

Enterococci: -11/100mL (mon geom), CAT > 24/100mL

NS = not specified by the state’s reuse regulation; TR = monitoring is not required but virus removal rates are prescribed by treatment requirement; NP = not permitted by the state 1 2 3

In Texas and Florida, spray irrigation (i.e., direct contact) is not permitted on foods that may be consumed raw (except Florida makes an exception for citrus and tobacco), and only irrigation types that avoid reclaimed water contact with edible portions of food crops (such as drip irrigation) are acceptable. In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the concentration of fecal coliform prior to disinfection: is ≤ 1,000 cfu per 100 mL, the CrT shall be 25 mg·min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg·min/L; and is ≥ 10,000 cfu per 100 mL the CrT shall be 120 mg·min/L. The requirements presented for Virginia are for food crops eaten raw. There are different requirements for food crops that are processed, which are presented in Table 4-10.

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2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-10 Agricultural reuse – non-food crops and processed food crops (where permitted)

Monitored Reclaimed Water Quality Requirements

Treatment (System Design) Requirements

Arizona

Unit processes UV dose, if UV disinfection used Chlorine disinfection requirements, if used

2

North Carolina Type 1

Texas Type II

Virginia Level 2

Washington Class C

Secondary treatment, with or without disinfection

Oxidized

Secondary treatment, basic disinfection

Secondary-23: oxidized, disinfected

Secondary treatment 1

Case-by-case

Filtration (or equivalent)

NS

Secondary treatment, disinfection

Oxidized, disinfected

NS

NS

NS

NS

NS

NS

75 mJ/cm2 at max day flow

NS

NS

NS

NWRI UV Guidelines

NS

TRC > 0.5 mg/L; 15 minutes contact time at peak hr flow1

Chlorine residual > 5 mg/L; 10 minutes actual modal contact time

NS

Chlorine residual > 1 mg/L; 15 minute contact time at peak hr flow

NS

TRC CAT < 1 mg/L; 30 minutes contact time at avg flow or 20 minutes at peak flow

Chlorine residual > 1 mg/L; 30 minutes contact time

NS

CBOD5: -20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

30 mg/L

NS

NS

NS

NS

NS

TSS

NS

NS

NS

Turbidity

NS

NS

NS

NS

Fecal coliform: -200/100mL in last 4 of 7 samples -800/100mL (max)

If nitrogen > 10 mg/L, special requirements Other may be mandated to protect groundwater NS = not specified by the state’s reuse regulation 1

New Jersey Type II RWBR

Secondary treatment, disinfection

-20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

Bacterial indicators

Nevada Category E

Class C

NS

Florida

2

Hawaii R2 Water

Class B

NS

BOD5 (or CBOD5)

California Undisinfected Secondary

Fecal coliform: -1000/100mL in last 4 of 7 samples -4000/100mL (max)

If nitrogen > 10 mg/L, special requirements may be mandated to protect groundwater

NS

-

Fecal coliform: -200/100mL (avg) -800/100mL (max)

-

Fecal coliform: -23/100mL (7-day med) -200/100mL (not more than one sample exceeds this value in 30 d)

-

NS

-

NS

Fecal coliform: -200/100mL (mon geom) -400/100mL (wk geom)

(NH3-N + NO3-N): < 10 mg/L (max)

NS

-10 mg/L (mon avg) -15 mg/L (daily max)

Without pond: 20 mg/L (or CBOD5 15 mg/L)

-30 mg/L (mon avg) -45 mg/L (max wk) 30 mg/L

With pond: 30 mg/L

or CBOD5 -25 mg/L (mon avg) -40 mg/L (max wk)

-5 mg/L (mon avg) -10 mg/L (daily max)

NS

-30 mg/L (mon avg) -45 mg/L (max wk)

30 mg/L

10 NTU (max)

NS

NS

NS

Fecal coliform or E. coli: -14/100mL (mon mean) -25/100mL (daily max)

Ammonia as NH3-N: -4 mg/L (mon avg) -6 mg/L (daily max)

:Fecal coliform or E. coli: -200/100mL (30-d geom) -800/100mL (max) Enterococci: -35/100mL (30-d geom) -89/100mL (max)

-

Fecal coliform: -200/100mL (mon geom), CAT > 800/100mL E. coli: -126/100mL (mon geom), CAT > 235/100mL

Total coliform: -23/100mL (7-d med) -240/100mL (max)

Enterococci: -35/100mL (mon geom), CAT > 104/100mL -

-

In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the concentration of fecal coliform prior to disinfection: is ≤ 1,000 cfu per 100 mL, the CrT shall be 25 mg·min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg·min/L; and is ≥ 10,000 cfu per 100 mL the CrT shall be 120 mg·min/L. Nevada prohibits public access and requires a minimum buffer zone of 800 feet for spray irrigation of non-food crops. (Category E, NAC 445A.2771).

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse

Treatment (System Design) Requirements

Table 4-11 Impoundments – unrestricted 1 Arizona Class A

Unit processes

UV dose, if UV disinfection used

Chlorine disinfection requirements, if used

California Disinfected Tertiary

Florida

Hawaii

Nevada

New Jersey

North Carolina

Texas Type I

Virginia Level 1

Washington Class A

Secondary treatment, disinfection

Oxidized, coagulated, filtered, disinfected2

NR

NR

NP

NR

NS

NS

Secondary treatment, filtration, high-level disinfection

Oxidized, coagulated, filtered and disinfected

NS

NWRI UV Guidelines

NR

NR

NP

NR

NS

NS

NS

NWRI UV Guidelines

NS

CrT > 450 mg·min/L; 90 minutes modal contact time at peak dry weather flow

NS

TRC CAT < 1 mg/L after minimum contact time of 30 mins at avg flow or 20 mins at peak flow

Chlorine residual > 1 mg/L; 30 minutes contact time

NR

NR

NP

NR

NS

Monitored Reclaimed Water Quality Requirements

10 mg/L (mon avg) BOD5

NS

NS

NR

NR

NP

NR

NS

5 mg/L

TSS

NS

NS

NR

NR

NP

NR

NS

NS

NS

30 mg/L

NS

-2 NTU (avg) for media filters -10 NTU (max) for media filters -0.2 NTU (avg) for membrane filters -0.5 NTU (max) for membrane filters

NR

NR

NP

NR

NS

3 NTU

2 NTU (daily avg), CAT > 5 NTU

-2 NTU (avg) -5 NTU (max)

Total coliform: -2.2/100mL (7-day med) -23/100mL (not more than one sample exceeds this value in 30 d) -240/100mL (max)

NR

Turbidity

Bacterial indicators

Other

Fecal coliform: -none detectable in last 4 of 7 samples -23/100mL (max)

If nitrogen > 10 mg/L, special requirements may be mandated to protect groundwater

Supplemental pathogen monitoring

or CBOD5: 8 mg/L (mon avg)

30 mg/L

Fecal coliform: -14/100mL (mon geom), CAT > 49/100mL

-

NR

-

NP

NP

NR

NR

NS

-

Fecal coliform or E.coli: -20/100mL (avg) -75/100mL (max)

E. coli: -11/100mL (mon geom), CAT > 35/100mL

Enterococci: -4/100mL (avg) -9/100mL (max)

Enterococci: -11/100mL (mon geom), CAT > 24/100mL

-

-

Total coliform: -2.2/100mL (7-day med) -23/100mL (max)

Specific reliability and redundancy requirements based on formal assessment

NS = not specified by the state’s reuse regulation; NR = not regulated by the state under the reuse program; NP = not permitted by the state 1 2

Arizona does not allow reuse for swimming or “other full-immersion water activity with a potential of ingestion" [AAC R18-9-704(G)(1)(b)]. Arizona also allows “Class A” and “A+” waters to be used for snowmaking, which is included in this definition. Disinfected tertiary recycled water that has not received conventional treatment shall be sampled/analyzed monthly for Giardia, enteric viruses, and Cryptosporidium during first 12 months of operation and use. Following the first 12 months, samples will be collected quarterly and ongoing monitoring may be discontinued after the first two years, with approval.

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2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-12 Impoundments – restricted California Disinfected Secondary-2.2

Florida

Hawaii R-2 Water

Nevada Category A

Secondary treatment, disinfection

Oxidized, disinfected

NR

Oxidized, disinfected

NS

NS

NR

NS

NR

Chlorine residual > 5 mg/L; actual modal contact time of 10 minutes

NR

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

Treatment (System Design) Requirements

Arizona Class B Unit processes

UV dose, if UV disinfection used

Chlorine disinfection requirements, if used

Monitored Reclaimed Water Quality Requirements

BOD5

NS

NS

NS

NS

New Jersey

North Carolina

Texas Type II

Virginia Level 2

Washington Class B

Secondary treatment, disinfection

NR

NS

NS

Secondary treatment, disinfection

Oxidized, disinfected

NS

NR

NS

NS

NS

NWRI UV Guidelines

NS

NR

NR

NS

NS

NS

Without pond: 20 mg/L (or CBOD5 15 mg/L)

TRC CAT < 1 mg/L after minimum contact time of 30 mins at avg flow or 20 mins at peak flow 30 mg/L (mon avg) 45 mg/L (max wk)

With pond: 30 mg/L

or CBOD5: 25 mg/L (mon avg) 40 mg/L (max wk)

Chlorine residual > 1 mg/L; 30 minutes contact time

30 mg/L

TSS

NS

NS

NR

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

NR

NS

NS

30 mg/L (mon avg) 45 mg/L (max wk)

30 mg/L

Turbidity

NS

NS

NR

NS

NS

NR

NS

NS

NS

NS

Bacterial indicators

Other

Fecal coliform: -200/100mL in last 4 of 7 samples -800/100mL (max)

If nitrogen > 10 mg/L, special requirements may be mandated to protect groundwater

Total coliform: -2.2/100mL (7-d med) -23/100 (not more than one sample exceeds this value in 30 d)

-

NR

-

Fecal coliform: -23/100mL (7-day med) -200/100mL (not more than one sample exceeds this value in 30 d)

-

Total coliform: -2.2/100mL (30-d geom) -23/100mL (max)

-

Fecal coliform or E. coli: -200/100mL (30-d geom) -800/100mL (max) NR

NR

NS

Enterococci: -35/100mL (30-d geom) -89/100mL (max)

-

-

Fecal coliform: -200/100mL (mon geom), CAT > 800/100mL E. coli: -126/100mL (mon geom), CAT > 235/100mL

Total coliform: -2.2/100mL (7-d med) -23/100mL (max)

Enterococci: -35/100mL (mon geom), CAT > 104/100mL -

Specific reliability and redundancy requirements based on formal assessment

NS = not specified by the state’s reuse regulation; NR = not regulated by the state under the reuse program; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements

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Chapter 4 | State Regulatory Programs for Water Reuse Table 4-13 Environmental reuse

Monitored Reclaimed Water Quality Requirements

Treatment (System Design) Requirements

Arizona

1

California

Florida

2

2 3 4 5 6

Nevada Category C

New Jersey

North Carolina Type 1

Texas

Virginia

4

Washington Class A

Unit processes

NR

NR

Secondary treatment, nitrification, basic disinfection

NR

Secondary treatment, disinfection

NR

Filtration (or equivalent)

NR

NS

Oxidized, coagulated, filtered, disinfected

UV dose, if UV disinfection used

NR

NR

NS

NR

NS

NR

NS

NR

NS

NWRI UV Guidelines

Chlorine disinfection requirements, if used

NR

NR

BOD5 (or CBOD5)

NR

NR

TSS

NR

NR

Bacterial indicators

NR

NR

Total Ammonia

Nutrients

NR

NR

NR

NR

TRC > 0.5 mg/L; 15 minutes contact time at peak hr flow3 CBOD5: -5 mg/L (ann avg) -6.25 mg/L (mon avg) -7.5 mg/L (wk avg) -10 mg/L (max) -5 mg/L (ann avg) -6.25 mg/L (mon avg) -7.5 mg/L (wk avg) -10 mg/L (max)

NR

NS

NR

NS

NR

NS

Chlorine residual > 1 mg/L; 30 minutes contact time

NR

30 mg/L (30-d avg)

NR

-10 mg/L (mon avg) -15 mg/L (daily max)

NR

NS

20 mg/L

NR

30 mg/L (30-d avg)

NR

-5 mg/L (mon avg) -10 mg/L (daily max)

NR

NS

20 mg/L

Fecal coliform: -200/100mL (avg) -800/100mL (max)

NR

Fecal coliform: -23/100mL (30-d geom) -240/100mL (max)

NR

Fecal coliform or E. coli: -14/100mL (mon mean) -25/100mL (daily max)

NR

NS

Total coliform: -2.2/100mL (7-d med) -23/100mL (max)

NR

NS

NR

Ammonia as NH3-N: -4 mg/L (mon avg) -6 mg/L (daily max)

NR

NS

Not to exceed chronic standards for freshwater

NR

NS

Phosphorus: 1 mg/L (ann avg)6

-2 mg/L (ann avg) -2 mg/L (mon avg) -3 mg/L (wk avg) -4 mg/L (max) Phosphorus: -1 mg/L (ann avg) -1.25 mg/L (mon avg) -1.5 mg/L (wk avg) -2 mg/L (max)

Nitrogen: -3 mg/L (ann avg) -3.75 mg/L (mon avg) -4.5 mg/L (wk avg) -6 mg/L (max) NS = not specified by the state’s reuse regulation; NR = not regulated by the state under the reuse program 1

Hawaii

NR

NS

NR

Phosphorus: 1 mg/L (max)5 Nitrogen: 4 mg/L (max)5

Though Arizona reuse regulations do not specifically cover environmental reuse, treated wastewater effluent meeting Arizona’s reclaimed water classes is discharged to waters of the U.S. and creates incidental environmental benefits. Arizona’s NPDES Surface Water Quality Standards includes a designation for this type of water, "Effluent Dependent Waters." Florida requirements are for a natural receiving wetland regulated under Florida Administrative Code Chapter 62-611 for Wetlands Application. In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the concentration of fecal coliform prior to disinfection: is ≤ 1,000 cfu per 100 mL, the CrT shall be 25 mg·min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg·min/L; and is ≥ 10,000 cfu per 100 mL the CrT shall be 120 mg·min/L. Wetlands in Virginia, whether natural or created as mitigation for impacts to existing wetlands, are considered state surface waters; release of reclaimed water into a wetland is regulated as a point source discharge and subject to applicable surface water quality standards of the state. These limits are not to be exceeded unless net environmental benefits are provided by exceeding these limits. The phosphorous limit is as an annual average for wetland augmentation/restoration while for stream flow augmentation is the same as that required to NPDES discharge limits, or in other words variable.

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2012 Guidelines for Water Reuse

Chapter 4 | State Regulatory Programs for Water Reuse Table 4-14 Industrial reuse

1 3

Monitored Reclaimed Water Quality Requirements

Treatment (System Design) Requirements

Arizona Unit processes

UV dose, if UV disinfection used Chlorine disinfection requirements, if used

2

California Disinfected Tertiary

1

Florida

3

Hawaii R-2 Water

Nevada Category E

Individual Reclaimed Water Permit, case-specific2

Oxidized, coagulated, filtered, disinfected

Secondary treatment, filtration, high-level disinfection

Oxidized, disinfected

Secondary treatment, disinfection

NS

NWRI UV Guidelines

NWRI UV Guidelines enforced, variance allowed

NS

NS

NS

CrT > 450 mg·min/L; 90 minutes modal contact time at peak dry weather flow

TRC > 1 mg/L; 15 minutes contact time at peak hr flow4

Chlorine residual > 5 mg/L, actual modal contact time of 10 minutes

NS

CBOD5: -20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

NS

Virginia Level 2

Washington Class A

Case-by-case

Filtration (or equivalent), unless there is no public access or employee exposure

NS

Secondary treatment, disinfection

Oxidized, coagulated, filtered and disinfected

NS

NS

NS

NS

NWRI UV Guidelines

NS

TRC CAT < 1 mg/L; 30 minutes contact time at avg flow or 20 minutes at peak flow

Chlorine residual > 1 mg/L; 30 minutes contact time

NS

TSS

NS

NS

5 mg/L (max)

30 mg/L or 60 mg/L depending on design flow

30 mg/L (30-d avg)

Case-by-case

NS

-2 NTU (avg) for media filters -10 NTU (max) for media filters -0.2 NTU (avg) for membrane filters -0.5 NTU (max) for membrane filters

Case-by-case (generally 2 to 2.5 NTU) Florida requires continuous on-line monitoring of turbidity as indicator for TSS

NS

NS

NS

Bacterial indicators

Pathogens

NS

NS

Fecal coliform: -75% of samples below detection -25/100mL (max)

NS

Giardia, Cryptosporidium sampling once each 2-yr period if high-level disinfection is required

Fecal coliform: -23/100mL (7-day med) -200/100mL (not more than one sample exceeds this value in 30 d)

NS

Fecal coliform: -2.2/100mL (30-d geom) -23/100mL (max)

TR

5

Texas Type II

NS

Total coliform: -2.2/100mL (7-day med) -23/100mL (not more than one sample exceeds this value in 30 d) -240/100mL (max)

6

North Carolina Type 1

BOD5 (or CBOD5)

Turbidity

1,5

New Jersey Type IV RWBR

NS

NS

NS

NS

-10 mg/L (mon avg) -15 mg/L (daily max)

Without pond: 20 mg/L (or CBOD5 15 mg/L)

-30 mg/L (mon avg) -45 mg/L (max wk) 30 mg/L

With pond: 30 mg/L

or CBOD5 -25 mg/L (mon avg) -40 mg/L (max wk)

-5 mg/ (mon avg) -10 mg/L (daily max)

NS

-30 mg/L (mon avg) -45 mg/L (max wk)

30 mg/L

10 NTU (max)

NS

NS

-2 NTU (avg) -5 NTU (max)

Fecal coliform or E. coli: -14/100mL (mon mean) -25/100mL (daily max)

Fecal coliform or E. coli: -200/100mL (30-d geom) -800/100mL (max) Enterococci: -35/100mL (30-d geom) -89/100mL (max)

NS

NS

Fecal coliform: -200/100mL (mon goem), CAT > 800/100mL E. coli: 126/100mL (mon geom), CAT > 235/100mL

Total coliform: -2.2/100mL (7-d med) -23/100mL (max)

Enterococci: -35/100mL (mon geom) -CAT > 104/100mL NS

NS

NS = not specified by the state’s reuse regulation; NR = not regulated by the state under the reuse program; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements 1 2 3

4 5 6

All state requirements are for cooling water that creates a mist or with exposure to workers, except for Texas and Hawaii. Texas requirements are for cooling tower makeup water and Hawaii includes industrial processes that do not generate mist, do not involve facial contact with recycled water, and do not involve incorporation into food or drink for humans or contact with anything that will contact food or drink for humans. Additional regulations for other industrial systems are in Appendix A of the 2004 Guidelines. Arizona regulates industrial reuse through issuance of an Individual Reclaimed Water Permit (Arizona Administrative Code [A.A.C.] R18-9-705 and 706), which provides case-specific reporting, monitoring, record keeping, and water quality requirements. For industrial uses in Florida, such as once-through cooling, open cooling towers with minimal aerosol drift and at least a 300 ft setback to the property line, wash water at wastewater treatment plants, or process water at industrial facilities that does not involve incorporation of reclaimed water into food or drink for humans or contact with anything that will contact food or drink for humans, that do not create a mist or have potential for worker exposure, less stringent requirements, such as basic disinfection (e.g., TRC > 0.5 mg/L, no continuous on-line monitoring of turbidity, fecal coliform < 200/100 mL, etc.), secondary treatment standards (e.g., TSS < 20 mg/L annual average, etc.), no sampling for pathogens (except in the case of open cooling towers regardless of setbacks), may apply. In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the concentration of fecal coliform prior to disinfection: is ≤ 1,000 cfu per 100 mL, the CrT shall be 25 mg·min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg·min/L; and is ≥ 10,000 cfu per 100 mL the CrT shall be 120 mg·min/L. For industrial uses, that do not create a mist or have potential for worker exposure, less stringent requirements may apply. In Virginia, these are the minimum reclaimed water standards for most industrial reuses of reclaimed water; more stringent standards may apply as specified in the regulation. For industrial reuses not listed in the regulation, reclaimed water standards may be developed on a case-by-case basis relative to the proposed industrial reuse.

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-15 Groundwater recharge - nonpotable reuse

Monitored Reclaimed Water Quality Requirements

Treatment (System Design) Requirements

Arizona

2

1

California

Florida

Regulated by Aquifer Protection Permit2

Case-by-case

UV dose, if UV disinfection used

NS

NS

Chlorine disinfection requirements, if used

NS

NS

BOD5 (or CBOD5)

NS

NS

Unit processes

3

5

6

Washington Class A

Hawaii

Nevada

New Jersey

North Carolina

Texas

Virginia

Secondary treatment, basic disinfection

Case-by-case

ND

NR

Aquifer Storage and Recovery in accordance with G.S. 143-214.2.

NR

NS

Oxidized, coagulated, filtered, nitrogen reduced, disinfected

NS

NS

ND

NR

NR

NR

NS

NWRI UV Guidelines

NS

ND

NR

NR

NR

NS

Chlorine residual > 1 mg/L 30 minutes contact time at peak hr flow

NS

ND

NR

NR

NR

NS

5 mg/L

NS

ND

NR

NR

NR

NS

5 mg/L

TRC > 0.5 mg/L; 15 minutes contact time at peak hr flow4 CBOD5: -20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

TSS

NS

NS

-20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

Turbidity

NS

NS

NS

NS

ND

NR

NR

NR

NS

-2 NTU (avg) -5 NTU (max)

Bacterial indicators

NS

NS

Fecal coliform: -200/100mL (avg) -800/100mL (max)

NS

ND

NR

NR

NR

NS

Total coliform: -2.2/100mL (7-d med) -23/100mL (max day)

Total Nitrogen

NS

NS

NS (nitrate < 12 mg/L)

NS

ND

NR

NR

NR

NS

Case-by-case

TOC

NS

NS

NS

NS

ND

NR

NR

NR

NS

Case-by-case

Primary and Secondary Drinking Water Standards

NS

NS

NS

NS

ND

NR

NR

NR

NS

Case-by-case

NR = not regulated by the state under the reuse program; ND = regulations have not been developed for this type of reuse; NS = not specified by the state’s reuse regulation 1 2

3 4 5 6

All state requirements are for groundwater recharge of a nonpotable aquifer. Groundwater recharge using reclaimed water is pervasive in Arizona but is not considered part of the reclaimed water program; Arizona Department of Environmental Quality (ADEQ) regulates quality under the Department's Aquifer Protection Permit Program (which governs all discharges that might impact groundwater). The Arizona Department of Water Resources (ADWR) oversees a program to limit withdrawals of groundwater to prevent groundwater depletion; municipalities and other entities can offset these pumping limitations by recharging reclaimed water through detailed permits under its Recharge Program. Higher treatment standards may be require, such as filtration, high level disinfection, total nitrogen below 10 mg/L, and meeting primary and secondary drinking water standards, if there may be a connection to a potable aquifer or other conditions such as groundwater recharge overlying the Biscayne Aquifer in Southeast Florida. In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the concentration of fecal coliform prior to disinfection: is ≤ 1,000 cfu per 100 mL, the CrT shall be 25 mg·min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg·min/L; and is ≥ 10,000 cfu per 100 mL the CrT shall be 120 mg·min/L. All discharges to groundwater for nonpotable reuse are regulated via a New Jersey Pollutant Discharge Elimination System Permit in accordance with N.J.A.C. 7:14A-1 et seq. and must comply with applicable Groundwater Quality Standards (N.J.A.C. 7:9C). In Virginia, groundwater recharge of a nonpotable aquifer may be regulated in accordance with regulations unrelated to the Water Reclamation and Reuse Regulation (9VAC25-740).

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Chapter 4 | State Regulatory Programs for Water Reuse

Table 4-16 Indirect potable reuse (IPR) Washington

Monitored Reclaimed Water Quality Requirements

Treatment (System Design) Requirements

Arizona Unit processes UV dose, if UV disinfection used Chlorine disinfection requirements, if used

1

2

4

Surface Percolation Class A

Direct Groundwater Recharge8 Class A

Streamflow Augmentation Case-by-case

Case-by-case

Oxidized with nitrogen reduction, filtered, disinfected

Oxidized, coagulated, filtered, RO-treated, disinfected

Oxidized, clarified, disinfected

NS

NWRI Guidelines

NWRI Guidelines

NWRI Guidelines

NS

NS

Chlorine residual > 1 mg/L; 30 minutes contact time at peak hr flow

Chlorine residual > 1 mg/L; 30 minutes contact time at peak hr flow

Chlorine residual to comply with NPDES permit

NR

5 mg/L

NS

30 mg/L

5 mg/L

30 mg/L

Hawaii

Nevada

New 7 Jersey

North Carolina

Texas

Virginia

Case-by-case

ND

NR

NR

Case-by-case

NS

ND

NR

NR

NS

California Oxidized, coagulated, filtered, disinfected, multiple barriers for pathogen and organics removal

Florida Secondary treatment, filtration, high-level disinfection, multiple barriers for pathogen and organics removal

NR

NWRI Guidelines3

NWRI UV Guidelines enforced, variance allowed

NR

CrT > 450 mg·min/L; 90 minutes modal contact time at peak dry weather flow3

TRC > 1 mg/L; 15 minutes contact time at peak hr flow5

NS

ND

NR

NR

NS

ND

NR

NR

BOD5 (or CBOD5)

NR

NS

CBOD5: -20 mg/L (ann avg) -30 mg/L (mon avg) -45 mg/L (wk avg) -60 mg/L (max)

TSS

NR

NS

5 mg/L (max)

NS

ND

NR

NR

NS

NS

30 mg/L

5 mg/L

30 mg/L

NR

-2 NTU (avg) for media filters -10 NTU (max) for media filters -0.2 NTU (avg) for membrane filters -0.5 NTU (max) for membrane filters

Case-by-case (generally 2 to 2.5 NTU) Florida requires continuous on-line monitoring of turbidity as indicator for TSS

NS

ND

NR

NR

3 NTU

NS

-2 NTU (avg) -5 NTU (max)

-0.1 NTU (avg) -0.5 NTU (max)

NS

Total coliform: -4/100mL (max)

NS

ND

NR

NR

NS

Total coliform: -2.2/100 (7-d med) -23/100 (max)

Total coliform: -1/100mL (avg) -5/100mL (max)

Fecal coliform: -200/100mL (avg) -400/100mL (max wk)

10 mg/L (ann avg)

NS

ND

NR

NR

NS

NS

NA

10 mg/L

NPDES requirements to receiving stream

NS

ND

NR

NR

NS

NS

NA

1 mg/L

NS

Compliance with most primary and secondary

NS

ND

NR

NR

NS

NS

Compliance with SDWA MCLs

Compliance with most primary and secondary

NPDES requirements to receiving stream

Giardia, Cryptosporidium sampling quarterly

NS

ND

NR

NR

NS

NS

NS

NS

NS

Turbidity

Bacterial indicators

NR

Total coliform: -2.2/100mL (7-day med) -23/100mL (not more than one sample exceeds this value in 30 d) -240/100mL (max)

Total Nitrogen

NR

10 mg/l (avg of 4 consecutive samples)

TOC

Fecal coliform or E. coli -20/100mL (30-d geom) -75/100mL (max) Enterococci -4/100mL (30d geom) -9/100mL (max)

-3 mg/L (mon avg) -5 mg/L (max); NR

0.5 mg/L

Primary and Secondary Drinking Water Standards

NR

Compliance with most primary and secondary

Pathogens

NR

TR

TOX6: < 0.2 (mon avg) or 0.3 mg/L (max); alternate limits allowed

NS = not specified by the state’s reuse regulation; NR = not regulated by the state under the reuse program; ND = regulations have not been developed for this type of reuse; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements

2012 Guidelines for Water Reuse

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Chapter 4 | State Regulatory Programs for Water Reuse 1 2 3 4

5 6 7 8

Arizona currently does not have IPR regulations; however, ADEQ regulates recharge facilities where mixed groundwater-reclaimed water may be recovered by a drinking water well through its Aquifer Protection Permit program (see Groundwater Recharge). The Governor's Blue Ribbon Panel on Water Sustainability issued a Report including a recommendation to develop a more robust regulatory/policy program to address IPR [US-AZ-Blue Ribbon Panel]. These requirements are DRAFT and were taken from CDPH Draft Regulations for Groundwater Replenishment with Recycled Water (CDPH, 2011). Additional pathogen removal is required for groundwater recharge through other treatment processes in order to achieve 12 log enteric virus reduction, 10 log Giardia cyst reduction, and 10 log Cryptosporidium oocysts reduction. Florida requirements are for the planned use of reclaimed water to augment Class F-I, G-I or G-II groundwaters (US drinking water sources) with a background TDS of 3,000 mg/L or less. For G-II groundwaters greater than 3,000 mg/L TDS, the TOC and TOX limits do not apply. Florida also includes discharges to Class I surface waters (public water supplies) or discharges less than 24 hours travel time upstream from Class I surface waters as IPR. For discharge to Class I surface waters or water contiguous to or tributary to Class I waters (defined as a discharge located less than or equal to 4 hours travel time from the point of discharge to arrival at the boundary of the Class I water), secondary treatment with filtration, high-level disinfection, and any additional treatment required to meet TOC and applicable surface water quality limits is required. The reclaimed water must meet primary and secondary drinking water standards, except for asbestos, prior to discharge. The TOX limit does not apply and a total nitrogen limit is based on the surface water quality. Outfalls for surface water discharges are not to be located within 500 feet (150 m) of existing or approved potable water intakes within Class I surface waters. Pathogen monitoring for Class I surface water augmentation is the same, except that if discharge is 24 to 48 hr travel time from domestic water supply, Giardia, Cryptosporidium sampling is once every 2 years. In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the concentration of fecal coliform prior to disinfection: is ≤ 1,000 cfu per 100 mL, the CrT shall be 25 mg·min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg·min/L; and is ≥ 10,000 cfu per 100 mL the CrT shall be 120 mg·min/L. Total organic halides (TOX) are regulated in Florida. For groundwater recharge reuse is on a case-by-case basis, State Groundwater Quality Standards must be met. Washington requires the minimum horizontal separation distance between the point of direct recharge and point of withdrawal as a source of drinking water supply to be 2,000 feet (610 meters) and must be retained underground for a minimum of 12 months prior to being withdrawn as a drinking water supply.

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Chapter 4 | State Regulatory Programs for Water Reuse

4.6 References

Anderson, P., N. Denslow, J. E. Drewes, A. Olivieri, D. Schlenk, and S. Snyder. 2010. Final Report Monitoring Strategies for Chemicals of Emerging Concern (CECs) in Recycled Water Recommendations of a Science Advisory Panel. SWRCB. Sacramento, CA. California Department of Public Health (CDPH), 2011. Draft Regulations for Groundwater Replenishment with Recycled Water, November 21, 2011. Retrieved August, 2012 from . Crook, J. 2010. NWRI White Paper: Regulatory Aspects of Direct Potable Reuse in California. National Water Research Food and Agriculture Organization of the United Nations (FAO). 1985. FAO Irrigation and Drainage Paper, 29 Rev. 1. Food and Agriculture Organization of the United Nations: Rome, Italy. Huffman, D.E., A. L. Gennaccaro, T. L. Berg, G. Batzer, and G. Widmer. 2006. “Detection of infectious parasites in reclaimed water.” Water Environment Research. 78(12):2297-302.

2012 Guidelines for Water Reuse

National Research Council (NRC). 2012. Water Reuse: Potential for Expanding the Nation's Water Supply Through Reuse of Municipal Wastewater. The National Academies Press: Washington, D.C. National Water Research Institute (NWRI). 2012. Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse, 3rd Edition. National Water Research Institute. Fountain Valley, CA. National Water Research Institute (NWRI). 2003. Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse, 2nd Edition. National Water Research Institute. Fountain Valley, CA. National Water Research Institute (NWRI). 2000. Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse. National Water Research Institute. Fountain Valley, CA. U.S. Environmental Protection Agency (EPA). 2004. Guidelines for Water Reuse. EPA. 625/R04/108. Environmental Protection Agency. Washington, D.C. WateReuse Association. 2009. How to Develop a Water Reuse Program: Manual of Practice, WRA-105. WateReuse Association. Alexandria, VA.

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Chapter 4 | State Regulatory Programs for Water Reuse

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2012 Guidelines for Water Reuse

CHAPTER 5 Regional Variations in Water Reuse This chapter summarizes current water use in the United States, discusses expansion of water reuse nationally to meet water needs, provides an overview of numerous water reuse case studies within the United States compiled for this document, and discusses variations pertaining to water reuse among different regions across the country. Representative water reuse practices are also described for each region.

Florida, and Texas), the 2005 USGS report did not include specific volumes of reclaimed water in the reference tables and figures (Kenny et al., 2009). The report tabulated water withdrawals from fresh surface water and groundwater and saline groundwater. The freshwater volumes did not recognize contributions from reclaimed water augmentation or wastewater plant discharges that contributed to the source water.

5.1 Overview of Water Use and Regional Reuse Considerations

Public supply 11%

This section describes the sources, volumes, and uses of freshwater in the United States.

5.1.1 National Water Use According to the USGS, total U.S. water use in 2005 3 was 410,000 mgd (1.55 billion m /d), up from 402,000 3 mgd (1.52 billion m /d) in 1995 (Kenny et al., 2009). Freshwater withdrawals made up 85 percent of the total, with the remaining 15 percent saline water withdrawals, mostly where seawater and brackish coastal water is used to cool thermoelectric power plants. About 80 percent of the total withdrawals were from surface water sources, with the remaining 20 percent of withdrawals sourcing groundwater (mostly freshwater as opposed to saline groundwater). As illustrated in Figure 5-1, the largest freshwater demands were associated with thermoelectric power and agriculture (irrigation, aquaculture, and livestock). Thermoelectric power plant cooling uses freshwater (34 percent of total withdrawals) and nearly all of the saline water withdrawals (15 percent of total withdrawals), totaling 49 percent of the demand. Agriculture requires freshwater for irrigation (31 percent of total withdrawals), aquaculture (2 percent), and livestock (1 percent), for a total of 34 percent of total withdrawals in the United States. Public supply and domestic self-supply water uses constitute 12 percent of the total demand. The remaining categories of industrial and mining water uses together were less than 5 percent of total water withdrawals estimated in this report (Kenny et al., 2009). Even though reclaimed water can be a significant source of cooling water for power plants (particularly in Arizona, California, 2012 Guidelines for Water Reuse

Thermoelectric 49%

Domestic selfsupply 1%

Irrigation 31%

Livestock 1% Mining 1%

Industrial 4%

Aquaculture 2%

Figure 5-1 Freshwater use by category in the United States (Source: Kenny et al., 2009)

Treated municipal wastewater represents a significant potential source of reclaimed water. As a result of the Federal Water Pollution Control Act Amendments of 1972, the CWA of 1977 and its subsequent amendments, centralized wastewater treatment has become commonplace in urban areas of the United States. Within the United States, the population 3 generates an estimated 32 bgd (121 million m /d) of municipal wastewater. The NRC Water Science & Technology Board estimates that a third of this could be reused (GWI, 2010; Miller, 2011; and NRC, 2012). Currently only about 7 to 8 percent of this water is reused, leaving a large area for potential expansion of the use of reclaimed water in the future (GWI, 2010 and Miller, 2012). As the world population continues to shift from rural to urban, the number of centralized

5-1

Chapter 5 | Regional Variations in Water Reuse

wastewater collection and treatment systems will also increase, creating significant opportunities to implement reclaimed water systems to augment water supplies and, in many cases, improve the quality of surface waters. A key issue nationally in water reuse is the existing potable water rates. Low potable water rates typically make water reuse less favorable. A comparison of potable and reclaimed water rates is provided in Table 7-1.

5.1.2 Examples of Reuse in the United States High water demand areas might benefit by augmenting existing water supplies with reclaimed water. Arid regions of the United States (such as the Southwest) are natural candidates for water reclamation, and significant reclamation projects are underway throughout this region. Yet, arid regions are not the only viable candidates for water reuse. As shown in Figure 5-2, water reuse is practiced widely throughout much of the United States, according to a survey conducted for this document. While the survey of reuse locations is not exhaustive, the information collected is meant to illustrate how widespread water reuse is in the United States. Data sources consulted for this survey included: 

WRA database of water reuse installations



California SWRCB inventory of reuse projects in California, available online (SWRCB, 2011)



FDEP inventory of reuse projects in Florida, available online (FDEP, 2012a)



Tennessee water reuse survey provided online by Tennessee Tech University (TTU) for years 2006 to 2011 (TTU, 2012)



TCEQ list of reuse installations



North Carolina Department of Environment and Natural Resources Division of Water Quality inventory of reuse installations

5-2



Georgia Environmental Protection inventory of reuse installations

Division



Case studies discussed in the 2004 EPA Guidelines for Water Reuse



Locations mentioned by other state regulators and experts in the review of this chapter

Figure 5-2 also shows the location of United States case studies on reclaimed water projects that were collected for this document to show the wide variety of types of applications. The case studies can be found in Appendix D. The map legend indicates the full title and authors of the case study, and provides a link to the location of the case study in the Appendix.

5.2 Regional Considerations

This section provides an overview of the context for water reuse in the United States. For the purposes of this document, states have been combined into eight regions corresponding with EPA’s regional division of the nation. The regions and states within each region are as follows: Northeast: (EPA Regions 1 and 2) Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Vermont, Puerto Rico, the U.S. Virgin Islands (USVI), and eight federally recognized tribal nations. Mid-Atlantic: (EPA Region 3) Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. Southeast: (EPA Region 4) Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee. Midwest and Great Lakes: (EPA Regions 5 and 7) Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, Ohio, and Wisconsin. South Central: (EPA Region 6) Arkansas, Louisiana, New Mexico, Oklahoma, and Texas.

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse

5-3

Chapter 5 | Regional Variations in Water Reuse

Figure 5-2 Legend Map Code Text code AZ-1

US-AZ-Gilbert

AZ-2

US-AZ-Tucson

AZ-3

US-AZ-Sierra Vista

AZ-4

US-AZ-Phoenix

AZ-5 AZ-6

US-AZ-Blue Ribbon Panel US-AZ-Prescott Valley

AZ-7

US-AZ-Frito Lay

CA-1

US-CA-Psychology

CA-2

US-CA-San Ramon

CA-3 CA-4 CA-5

US-CA-San Diego US-CA-Orange County US-CA-North City

CA-6

US-CA-Santa Cruz

CA-7

US-CA-Monterey

CA-8

US-CA-Southern California MWD

CA-9

US-CA-Los Angeles County

CA-10

US-CA-Elsinore Valley

CA-11

US-CA-Temecula

CA-12 CA-13

US-CA-Santa Ana River US-CA-VanderLans

CA-14

US-CA-Pasteurization

CA-15 CA-16 CO-1 CO-2 CO-3 CO-4 CO-5 CO-6 DC-1 FL-1 FL-2 FL-3 FL-4 FL-5 FL-6 FL-7 FL-8

US-CA-Regulations US-CA-West Basin US-CO-Denver Zoo US-CO-Denver US-CO-Denver Energy US-CO-Denver Soil US-CO-Sand Creek US-CO-Water Rights US-DC-Sidwell Friends US-FL-Miami So District Plant US-FL-Pompano Beach US-FL-Orlando E. Regional US-FL-Economic Feasibility US-FL-Reedy Creek US-FL-Marco Island US-FL-Everglade City US-FL-Orlando Wetlands

5-4

Case Study Name Town of Gilbert Experiences Growing Pains in Expanding the Reclaimed Water System Tucson Water: Developing a Reclaimed Water Site Inspection Program Environmental Operations Park 91st Avenue Unified Wastewater Treatment Plant Targets 100 Percent Reuse Arizona Blue Ribbon Panel on Water Sustainability Effluent Auction in Prescott Valley, Arizona Frito-Lay Process Water Recovery Treatment Plant, Casa Grande, Arizona The Psychology of Water Reclamation and Reuse: Survey Findings and Research Roadmap Managing a Recycled Water System through a Joint Powers Authority: San Ramon Valley City of San Diego – Water Purification Demonstration Project Groundwater Replenishment System, Orange County, California EDR at North City Water Reclamation Plant Water Reuse Study at the University of California Santa Cruz Campus Long-term Effects of the Use of Recycled Water on Soil Salinity Levels in Monterey County Metropolitan Water District of Southern California’s Local Resource Program Montebello Forebay Groundwater Recharge Project using Reclaimed Water, Los Angeles County, California Recycled Water Supplements Lake Elsinore Replacing Potable Water with Recycled Water for Sustainable Agricultural Use Water Reuse in the Santa Ana River Watershed Leo J. Vander Lans Water Treatment Facility Use of Pasteurization for Pathogen Inactivation for Ventura Water, California California State Regulations West Basin Municipal Water District: Five Designer Waters Denver Zoo Denver Water Xcel Energy’s Cherokee Station Effects of Recycled Water on Soil Chemistry Sand Creek Reuse Facility Reuse Master Plan Water Reuse Barriers in Colorado Smart Water Management at Sidwell Friends School South District Water Reclamation Plant City of Pompano Beach OASIS Eastern Regional Reclaimed Water Distribution System Economic Feasibility of Reclaimed Water to Users Reuse at Reedy Creek Improvement District Marco Island, Florida, Wastewater Treatment Plant Everglade City, Florida City of Orlando Manmade Wetlands System

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

Figure 5-2 Legend Map Code Text code FL-9

US-FL-SWFWMD Partnership

FL-10

US-FL-Altamonte Springs

FL-11

US-FL-Clearwater

FL-12

US-FL-Turkey Point

GA-1

US-GA-Clayton County

GA-2

US-GA-Forsyth County

GA-3 HI-1

US-GA-Coca Cola US-HI-Reuse

MA-1

US-MA-Southborough

MA-2

US-MA-Hopkinton

MA-3

US-MA-Gillette Stadium

ME-1 MN-1 NC-1

US-ME-Snow US-MN-Mankato US-NC-Cary

NY-1

US-NY-PepsiCo

PA-1

US-PA-Kutztown

PA-2

US-PA-Mill Run

TN-1 TX-1 TX-2

US-TN-Franklin US-TX-San Antonio US-TX-Big Spring

TX-3

US-TX-Landscape Study

TX-4

US-TX-NASA

TX-5

US-TX-Wetlands

VA-1 VA-2

US-VA-Occoquan US-VA-Regulation

WA-1

US-WA-Sequim

WA-2

US-WA-Regulations

WA-3

US-WA-King County

WA-4

US-WA-Yelm

2012 Guidelines for Water Reuse

Case Study Name Regional Reclaimed Water Partnership Initiative of the Southwest Florida Water Management District The City of Altamonte Springs: Quantifying the Benefits of Water Reuse Evolution of the City of Clearwater’s Integrated Water Management Strategy Assessing Contaminants of Emerging Concern (CECs) in Cooling Tower Drift Sustainable Water Reclamation Using Constructed Wetlands: The Clayton County Water Authority Success Story On the Front Lines of a Water War, Reclaimed Water Plays a Big Role in Forsyth County, Georgia Recovery and Reuse of Beverage Process Water Reclaimed Water Use in Hawaii Sustainability and LEED Certification as Drivers for Reuse: Toilet Flushing at The Fay School Decentralized Wastewater Treatment and Reclamation for an Industrial Facility, EMC Corporation Inc., Hopkinton, Massachusetts Sustainability and Potable Water Savings as Drivers for Reuse: Toilet Flushing at Gillette Stadium Snowmaking with Reclaimed Water Reclaimed Water for Peaking Power Plant: Mankato, Minnesota Town of Cary, North Carolina, Reclaimed Water System Identifying Water Streams for Reuse in Beverage Facilities: PepsiCo ReCon Tool The Water Purification Eco-Center Zero-Discharge, Reuse, and Irrigation at Fallingwater, Western Pennsylvania Conservancy Franklin, Tennessee Integrated Water Resources Plan San Antonio Water System Water Recycling Program Raw Water Production Facility: Big Spring Plant Site Suitability for Landscape Use of Reclaimed Water in the Southwest U.S. Water Recovery System on the International Space Station East Fork Raw Water Supply Project: A Natural Treatment System Success Story Potable Water Reuse in the Occoquan Watershed Water Reuse Policy and Regulation in Virginia City of Sequim’s Expanded Water Reclamation Facility and Upland Reuse System Washington State Regulations Demonstrating the Safety of Reclaimed Water for Garden Vegetables City of Yelm, Washington

5-5

Chapter 5 | Regional Variations in Water Reuse

Mountains and Plains: (EPA Region 8) Colorado, Montana, South Dakota, North Dakota, Utah, and Wyoming. Pacific Southwest: (EPA Region 9) Arizona, California, Hawaii, Nevada, U.S. Pacific Insular Area Territories (Territory of Guam, Territory of American Samoa, and the Commonwealth of the Northern Mariana Islands (CNMI), and 147 federally recognized tribal nations. Pacific Northwest: (EPA Region Washington, Idaho, and Alaska.

10)

Oregon,

In this section, five areas of variation are discussed for each region related to water reuse. These include: 

Population and land use



Precipitation and climate



Water use by sector



States’ regulatory context



Context and drivers of water reuse

The following are the sources of data cited for these discussions: 

Population: U.S. Census Bureau (USCB) – percent change in 2000 and 2010 resident population data in each region (USCB, n.d.)



Land Use: National Resources Inventory – percent change from 1997 to 2007 in developed, non-federal land in each region, as a percentage of total region land area (USDA, 2009)



Precipitation: National Oceanic and Atmospheric Administration (NOAA) 30-year annual rainfall data for each state (1971 to 2000). City precipitation figures were averaged for each state, except where noted for New Hampshire (NOAA, n.d.)



Water use: Estimated Use of Water in the United States in 2005, USGS. Water use by sector was first calculated for each state, after which a regional average was calculated (Kenny et al, 2009)

5-6

States and territories were surveyed to obtain information on regulations and guidelines governing water reuse. An overall summary of the states and territories that have water reuse regulations and guidelines is provided in Table 4-5. Links to regulatory websites are provided in Appendix C. As population growth is a key driver for infrastructure development, including water reuse facilities, the changes in population and developed land are presented for each region in the sections that follow. As an overview, the population change since 1990 is also provided in Table 5-1 for all of the regions.

5.2.1 Northeast: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Vermont, Puerto Rico, the U.S. Virgin Islands, and Eight Federally Recognized Tribal Nations While EPA Regions 1 and 2 comprise Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Vermont, Puerto Rico, the U.S. Virgin Islands, and eight federally recognized tribal nations, this section focuses only on the regulatory context and drivers for water reuse in the seven states in the Northeast region of the United States and the USVI, a U.S. territory. Information is not available at this time for Puerto Rico and the eight federally recognized tribal nations in Region 2. There are both challenges and opportunities to wastewater reclamation and reuse in the Northeast. The major drivers include state regulatory changes, urban hydrology, precipitation, seasonal use, water rates, and water use by sector. Generally speaking, wastewater reclamation is growing at a very slow rate, with an estimated reuse of approximately 8 to 10 mgd (350 to 438 L/s) of reclaimed water. Reuse in the Northeast is still a novel concept. Where reuse has been implemented, it has been used by municipalities to augment and buffer stressed potable water supplies, landscape irrigation, or on-site installations (e.g., LEED certified facilities). Often, private developers, industry, and in some cases public-private partnerships collaborate to go beyond the standards of basic environmental compliance and create a vision for integrated and sustainable water resources. Water reuse then becomes a key element in their water supply plans.

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

Table 5-1 Percent change in resident population in each region during the periods 1990-2000, 2000-2010, and 1990-2010 (USCB, n.d.) % change 1990-2000

% change 2000-2010

% change 1990-2010

United States

13.2

9.7

24.1

NORTHEAST REGION

6.1

3.2

9.5

Connecticut

3.6

4.9

8.7

Maine

3.8

4.2

8.2

Massachusetts

5.5

3.1

8.8

New Hampshire

11.4

6.5

18.7

Rhode Island

4.5

0.4

4.9

Vermont

8.2

2.8

11.2

New Jersey

8.9

4.5

13.7

New York

5.5

2.1

7.7

MID-ATLANTIC REGION

7.3

7.2

15.1

Delaware

17.6

14.6

34.8

District of Columbia

-5.7

5.2

-0.9

Maryland

10.8

9.0

20.7

Pennsylvania

3.4

3.4

6.9

Virginia

14.4

13.0

29.3

West Virginia

0.8

2.5

3.3

SOUTHEAST REGION

19.1

14.7

36.6

Alabama

10.1

7.5

18.3

Florida

23.5

17.6

45.3

Georgia

26.4

18.3

49.5

Kentucky

9.7

7.4

17.7

Mississippi

10.5

4.3

15.3

North Carolina

21.4

18.5

43.9

South Carolina

15.1

15.3

32.7

Tennessee

16.7

11.5

30.1

MIDWEST AND GREAT LAKES REGION

8.0

3.9

12.2

Illinois

8.6

3.3

12.2

Indiana

9.7

6.6

16.9

Michigan

6.9

-0.6

6.3

Minnesota

12.4

7.8

21.2

Ohio

4.7

1.6

6.4

Wisconsin

9.6

6.0

16.3

Iowa

5.4

4.1

9.7

Kansas

8.5

6.1

15.2

Missouri

9.3

7.0

17.0

Nebraska

8.4

6.7

15.7

State or Region

2012 Guidelines for Water Reuse

5-7

Chapter 5 | Regional Variations in Water Reuse

Table 5-1 Percent change in resident population in each region during the periods 1990-2000, 2000-2010, and 1990-2010 (USCB, n.d.) % change 1990-2000

% change 2000-2010

% change 1990-2010

SOUTH CENTRAL REGION

17.9

15.5

36.1

Arkansas

13.7

9.1

24.0

Louisiana

5.9

1.4

7.4

New Mexico

20.1

13.2

35.9

Oklahoma

9.7

8.7

19.3

Texas

22.8

20.6

48.0

MOUNTAINS AND PLAINS REGION

22.7

16.1

42.4

Colorado

30.6

16.9

52.7

Montana

12.9

9.7

23.8

North Dakota

0.5

4.7

5.3

South Dakota

8.5

7.9

17.0

Utah

29.6

23.8

60.4

Wyoming

8.9

14.1

24.3

PACIFIC SOUTHWEST REGION

18.1

13.0

33.5

Arizona

40.0

24.6

74.4

California

13.8

10.0

25.2

Hawaii

9.3

12.3

22.7

Nevada

66.3

35.1

124.7

PACIFIC NORTHWEST REGION

21.3

14.2

38.5

Alaska

14.0

13.3

29.1

Idaho

28.5

21.1

55.7

Oregon

20.4

12.0

34.8

Washington

21.1

14.1

38.2

State or Region

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Chapter 5 | Regional Variations in Water Reuse

5.2.1.1 Population and Land Use

5.0 4.0 3.5

Connecticut

3.0

Maine

2.5

Massachusetts

2.0

New Hampshire

1.5

Rhode Island

1.0

Vermont

0.5

New Jersey New York

Dec

Oct

Nov

Sept

Jul

Aug

Jun

Apr

May

Mar

Jan

Feb

0.0

Month

Figure 5-4 Average monthly precipitation (1971-2000) for states in the Northeast region

16.0 13.4

14.0

4.5

Average Rainfall (inches)

Another factor in the development of reuse programs in the Northeast is the significant change in urbanization of major population centers and in the land use surrounding those centers. As population increases, water resources are stressed and water reuse can become an attractive option. Figure 5-3 compares the percent change in the overall population of the Northeast region to the population change of the entire United States over the past decade, along with the change in the percentage of developed land.

Percent Change

12.0 9.7

10.0 8.0 6.0

5.2.1.3 Water Use by Sector Northeast Region

6.1

5.7

US

Figure 5-5 shows freshwater use by sector in the Northeast.

4.0

Domestic selfsupply Irrigation 2% 1%

2.0 0.0

Population

Public supply 16%

Land Use

Figure 5-3 Percent change in population (2000-2010) and developed land (1997-2007) in the Northeast Region, compared to the United States

While the percent population change in the Northeast has lagged behind other regions, the developed land percent change in the Northeast has outpaced the United States average.

5.2.1.2 Precipitation and Climate The most significant impediment to reuse is the prolific amount of annual precipitation in the Northeast. The annual average precipitation is approximately 42 in (106.5 cm), with monthly precipitation between 3 in (7.5 cm) and 4 in (10 cm). The annual average temperature in the region is approximately 53 degrees F (11.6 degrees C). The region’s high precipitation and low annual temperature, combined with a lower than average water evaporation rate, results in an abundance of water for recharge of water resources on a regional basis. Figure 5-4 depicts typical monthly precipitation by state.

Thermoelectric 72%

Livestock <1% Aquaculture 2% Industrial 6% Mining 1%

Figure 5-5 Freshwater use by sector for the Northeast region

The opportunities for water reuse are similar among the Northeast states. The greatest benefit resides in the energy sector, followed by irrigation and the industrial sector. These sectors define the future for reclamation in the Northeast and highlight the importance of the energy-water nexus. Sustainable water management requires balancing these potable demands through source substitution with reclaimed water, which can reduce stress on potable water supplies. The energy sector in Connecticut is second only to Massachusetts energy water demands. Recently, the University of Connecticut developed a plan for using

2012 Guidelines for Water Reuse

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Chapter 5 | Regional Variations in Water Reuse

reclaimed water at its power plant on campus. Another industrial facility in Connecticut uses reclaimed water where it’s feasible to meet a zero-discharge wastewater permit. Maine has significant potable water resources and, as illustrated in Figure 5-5, has the greatest opportunity for water reclamation within the energy and industrial sector. Because the manufacturing of paper and wood products demands large amounts of water, it is likely that water reuse projects will develop in these sectors as potable water resources are seasonally and locally stressed. The energy sector in Massachusetts has already provided water reclamation opportunities at power plants like Dominion Power’s Brayton Point Power Plant in Somerset, Mass. Industrial wastewater reclamation is also a growing market sector. An excellent example of industrial wastewater reclamation is the EMC Headquarters in Hopkinton [US-MAHopkinton]. Additionally, the use of reclaimed wastewater for golf course irrigation is also a market sector that has growth potential. Similar to the opportunities described above, New Hampshire has looked at development of water reuse at industrial parks. Rhode Island reuse projects include the irrigation of the Jamestown Golf Course, as well as a private golf course in Portsmouth, both of which are island communities in Narragansett Bay. Also in Rhode Island, there is a planned reuse project in a mixed-use community in Kingston. A power plant based at the Central Landfill in Johnston, R.I., is the largest reclaimed water project in the Northeast. In Vermont, the energy sector provides the greatest opportunity for water reuse, followed by industrial reuse. There is limited water reuse in New York with one case study in Chapter 5.7.7 of the 2004 guidelines discussing the Oneida Indian Nation (EPA, 2004). In this document, Section 2.4.2 Alternative Water Resources includes a discussion of on-site reuse in Battery Park, New York City, N.Y. An additional potential driver for reuse in the Northeast is increasingly strict nutrient removal requirements in NPDES permits. In locations with new nutrient limits, water reuse may be a favorable alternative to enhanced treatment purely for discharge, as has been demonstrated in other parts of the United States, including Florida, Oregon, and Washington.

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5.2.1.4 States’ and Territories’ Regulatory Context Based on the limited number of water reuse projects undertaken in the Northeast, regulatory requirements or guidelines for reuse projects have not been implemented in most states. Massachusetts, New Jersey, and Vermont are the only states in the Northeast with water reuse regulations. There are no comprehensive inventories of reuse projects by state, nor is there a data warehouse on the guidelines or permitted water quality criteria applied to each project. Massachusetts The Commonwealth of Massachusetts promulgated water reuse regulations in March 2009. The regulations were developed within 314 Code of Massachusetts Regulations (CMR) 20.00 entitled “Reclaimed Water Permit Program and Standards” and 314 CMR 5.00 regulations entitled “Groundwater Discharge.” The key elements of the regulations were to protect public groundwater supplies by requiring a TOC limit when there is a discharge to the groundwater as a surrogate for endocrine disrupting compounds and contaminants within a specified travel time in the aquifer. New Hampshire New Hampshire does not have regulations governing water reuse but encourages it and has developed a position statement recognizing that water reuse can both reduce stress on groundwater resources as well as decrease surface water quality degradation. The New Hampshire Department of Environmental Services developed a guidance document identifying design criteria for reuse of reclaimed wastewater. Water reclamation projects are approved on a caseby-case basis. Rhode Island Rhode Island developed water reuse guidelines in 2007 for four allowable water reuse categories, including restricted irrigation, unrestricted irrigation, non-contact cooling water, and agricultural reuse for non-food crops. The Department of Environmental Management’s Office of Water Resources has established water quality criteria, signage, and setback distances for these four categories of reuse.

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

Vermont Vermont has adopted rules for indirect discharge that require that land-based discharge (including forested spray fields) be considered prior to approval of surface water discharge. New York There are no formal guidelines or regulations in New York, and initial work on guidelines was suspended due to budget constraints. In highly developed areas such as Manhattan, the cost to extend dual piping systems from central wastewater reclamation facilities is cost prohibitive. There are isolated uses of reclaimed water in the state for cooling purposes with supply and quality parameters agreed to in site specific contracts. The 2004 guidelines (Chapter 5.7.7) recounts development of an intergovernmental agreement between the Oneida Indian Nation and the city of Oneida. The city’s reclaimed water was supplied to the Indian Nation to enable development of a casino and golf complex by allowing the irrigation demands of the complex to be met without stressing water resources. New Jersey In January 2005, the New Jersey Department of Environmental Protection issued a draft “Technical Manual for Reclaimed Water for Beneficial Reuse,” and proposed regulation in 2008. These regulations were codified on January 5, 2009 as New Jersey Administrative Code 7:14A-2.15. Section 2.15 establishes application requirements for Reclaimed Water for Beneficial Reuse (RWBR) and states that any feasibility studies conducted shall be performed in accordance with the Technical Manual. The regulations define two main categories of RWBR— public access and restricted access. The Technical Manual provides detailed information to applicants on the procedure for developing and implementing an RWBR program. Connecticut and Maine There are no formal regulations regarding water reuse in Connecticut or Maine. Installations are approved on a case-by-case basis. USVI Currently, there are no water reuse regulations promulgated by the USVI. Water reuse for irrigation is limited to small, on-site installations and no large scale or public projects have been undertaken. Discharges

2012 Guidelines for Water Reuse

to above ground irrigation systems are regulated under the USVI Territorial Pollutant Discharge Elimination System Permitting and Compliance permit program, while below ground dispersal systems are reviewed on a case-by-case basis. At the time of publication, USVI is reviewing draft regulations for small scale water reuse systems for groundwater recharge and irrigation. Water reuse for IPR, industrial, or recreational applications have not been proposed in the USVI, but if proposed, they would be approved on a case-bycase basis.

5.2.1.5 Context and Drivers of Water Reuse Potable water rates vary fairly dramatically by state and regionally within each state in the Northeast, depending on whether the source is a surface water or groundwater resource. Several aquifers are stressed on a seasonal basis; there are even instances of surface waters being depleted within coastal river basins in recent years, driving up potable water rates. Obviously, the high cost of the potable water supply provides an incentive for wastewater reclamation. For example, in Massachusetts the Ipswich River Basin ran dry during the peak summer demands of 2006 and 2007. Currently, potable water rates in the Northeast range from a low of less than $1.00/1,000 gallons ($0.26/1000 L) to a high of over $9.00/1,000 gallons ($2.38/1000 L) regionally. Since adequate potable water supply is not always available for large industrial projects regardless of the water rate, industrial facilities such as power plants have developed the largest water reclamation projects in the region. Rhode Island has the distinction of having the largest reclaimed water project in the Northeast at a power plant at the Central Landfill in Johnston, R.I. that pumps 5 mgd (219 L/s) of reclaimed water 12 mi (19.3 km) from the Cranston, R.I., WWTP for use in the on-site cooling towers. In Connecticut there are two active reuse projects (for golf course irrigation and an industrial manufacturing facility) and one facility near start-up at the University of Connecticut. Reclaimed water is used for snowmaking in several states in New England as a means to allow for continued discharge of treated effluent from zero discharge lagoon and LAS during the winter. Several ski resorts in Maine utilize reclaimed water for snowmaking, as described in a case study (US-MESnow). In Vermont, one ski area, one highway rest

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Chapter 5 | Regional Variations in Water Reuse

Several water reclamation systems from Massachusetts are highlighted in the case studies. In Southborough, a private school has installed a small wastewater treatment system to reclaim water for toilet flushing as part of a campus expansion that included LEED certification of buildings [US-MA-Southborough]. In Hopkinton, a manufacturer of electronic data storage systems has installed a wastewater treatment and reclamation plant to reuse water for toilet flushing and irrigation, which recharges groundwater. As Hopkinton has faced water shortages during summer peak seasonal demand, the project has reduced the potable water demand on a seasonally limited aquifer and has provided needed groundwater recharge [USMA-Hopkinton]. In the town of Foxborough, when the new Gillette Stadium was being built, the New England Patriots management worked with the town and the Massachusetts Department of Environmental Protection to construct a new wastewater reclamation system for toilet flushing and groundwater recharge. The increase in wastewater generated during home games would have otherwise overwhelmed the town’s wastewater treatment system, as well as severely stressed the town’s groundwater supplies [US-MAGillette Stadium]. The Metropolitan Area Planning Council (MAPC) published a guide for expanding water reuse in Massachusetts that includes several other case studies on water reuse in the state (MAPC, 2005). The objective of the RWBR program in the state of New Jersey is to incorporate RWBR language into all sanitary sewerage treatment plant permits. As of 2011, 118 facilities have been permitted to utilize RWBR. Of these facilities, 27 are utilizing RWBR for a variety of uses ranging from cooling water, WWTP wash down, and golf course irrigation to cage/pen washing at a county zoo. USVI Public potable water supply serves approximately 30 percent of the USVI, while the remaining 70 percent collect rainwater or use wells to draw groundwater for drinking. Of that 70 percent, approximately 15 percent use wells, with the remaining population relying on rainwater cisterns. While the annual rainfall is

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significant, there is a dry season, and the eastern end of the island of St. Croix is particularly dry year round, providing a drive to conserve water. There also have been recent shortages of public water supply on the island of St. Thomas. Overall, however, provided conservation practices are used, water demands are generally met by supply. Thus, scarcity is not a driver for large-scale water reuse. Nonetheless, small-scale water reuse for irrigation of small plots, primarily for landscaping, does occur in the USVI, particularly in the drier areas (e.g., the eastern end of St. Croix). Commercial agriculture, primarily located on St. Croix, currently does not employ water reuse.

5.2.2 Mid-Atlantic: Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia This section focuses on the regulatory context and drivers for water reuse in five states and the District of Columbia in the Mid-Atlantic region.

5.2.2.1 Population and Land Use According to the 2010 U.S. Census, the population in the Mid-Atlantic states totals around 30 million with the largest population density being the Washington, D.C.Baltimore-Northern Virginia metropolitan area. The coastal areas of the upper Mid-Atlantic region have been thoroughly urbanized, with little to no areas of rural farmland. However, West Virginia and parts of Virginia remain largely rural with pockets of urbanization. Figure 5-6 compares the percent change population in the Mid-Atlantic to the entire United States from 2000-2010 and percent change in developed land coverage from 1997-2007. 14.0

12.8

12.0

Percent Change

area, and one building at the University of Vermont are currently using reclaimed water for toilet and urinal flushing. In addition, forested spray fields are used for disposal of treated wastewater in areas of Vermont.

9.7

10.0 8.0

7.2 5.7

6.0

Mid-Atlantic Region US

4.0 2.0 -

Population

Land Use

Figure 5-6 Change in population (2000-2010) and developed land (1997-2007) in the Mid-Atlantic region, compared to the United States

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Chapter 5 | Regional Variations in Water Reuse

5.2.2.2 Precipitation and Climate The climate in the Mid-Atlantic region is largely classified as humid subtropical. Spring and fall are warm, while winter is cool with annual snowfall averaging 14.6 in (37 cm). Winter temperatures average around 38 degrees F (3.3 degrees C) from mid-December to mid-February. Summers are hot and humid with a July daily average of 79.2 degrees F (26.2 degrees C). The combination of heat and humidity in the summer brings very frequent thunderstorms and, therefore, abundant precipitation during the warmest months. Figure 5-7 depicts average monthly precipitation in the Mid-Atlantic region by state.

Average Rainfall (inches)

5.0 4.5 4.0 3.5 3.0

Delaware

2.5

Washington, DC

2.0

Maryland

1.5

Pennsylvania

1.0

Virginia

0.5

West Virginia Dec

Oct

Nov

Sept

Jul

Aug

Jun

Apr

May

Mar

Jan

Feb

0.0

Month

Figure 5-7 Average monthly precipitation in the Mid-Atlantic region

5.2.2.3 Water Use by Sector Figure 5-8 shows freshwater use by sector in the MidAtlantic Region. Public supply 8%

Domestic selfIrrigation supply 1% 1% Livestock <1% Aquaculture 2% Industrial 7% Mining <1%

Thermoelectric 81%

Figure 5-8 Freshwater use by sector for the Mid-Atlantic region

2012 Guidelines for Water Reuse

As for the Northeast region, the greatest possible opportunity for water reuse in the Mid-Atlantic region is in the energy sector.

5.2.2.4. States’ Regulatory Context

Delaware The Delaware Division of Water administers the state’s reclaimed water permits, which are primarily for agricultural irrigation, a reuse that has been practiced since the 1970s. There are 23 permitted agricultural operations covering more than 2,200 acres, plus two golf courses and several wooded tracks. State regulations require advanced treatment for unrestricted access use; specify water quality limitations, including bacteriological standards; and require set back distances. Agricultural application rates are limited both hydraulically and by nutrient loading limits. Reclaimed water irrigation of crops intended for human consumption without processing is not allowed. District of Columbia The District of Columbia currently does not have any regulations or guidelines addressing water reuse but considers projects on a case-by-case basis. The city is currently developing rules and water quality requirements for stormwater use. Pennsylvania and Maryland Pennsylvania and Maryland have guidelines for water reuse. The Maryland Department of Environment has Guidelines for Land Application/Reuse of Treated Municipal Wastewaters, last revised in 2010. There are two quality levels (Class I and II). The guidelines provide buffer zone requirements and requirements for zero nitrogen addition to groundwaters in new permits. The 2010 amendments added a Class III water for non-restricted urban irrigation use and regulations proposed for reuse with a Class IV water allowing use in commercial settings (laundries, car wash, snowmaking, air conditioning, closed loop cooling, window washing, and pressure cleaning), irrigation for food crops (with no contact with the edible portion of the crop), and industrial facilities (washing aggregate, cooling waters, concrete manufacture, parts washing, and equipment operations). Virginia Virginia adopted new regulations for water reuse in 2008 under the Department of Environmental Quality (DEQ). In addition to the DEQ regulations, which

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Chapter 5 | Regional Variations in Water Reuse

govern the centralized reclamation of domestic, municipal, or industrial wastewater and subsequent reuse, other Virginia state agencies have regulations or guidelines that affect water reuse, determined in most cases by the type of wastewater to be reclaimed. The Virginia Department of Health has regulations that allow the on-site treatment and reuse of reclaimed water in conjunction with a permitted on-site system for toilet flushing, and provides guidelines for the use of harvested rainwater and graywater. The Virginia Department of Housing and Community Development has regulations for the indoor treatment and plumbing of graywater and harvested rainwater, and for the indoor plumbing of reclaimed water meeting appropriate regulatory standards administered by the DEQ for indoor uses. The Virginia Department of Conservation and Recreation has limited regulations for the use of stormwater and evaluates such proposals on a case-by-case basis. A discussion of the development of the Virginia water reuse regulations is provided in a case study [US-VARegulations]. Water rights in Virginia adhere to the Riparian Doctrine, which protects the beneficial water uses of downstream riparian owners. A more detailed discussion of water rights and how they may affect the reclamation and reuse of wastewater is provided in Chapter 4. As a result of the Riparian Doctrine and Virginia’s water withdrawal permit program, communities that do not have downstream riparian owners or permitted withdrawals to contend with may have a greater range of water reclamation and reuse options, including IPR and nonpotable uses. In contrast, communities with downstream riparian owners may implement IPR in lieu of nonpotable reuse of reclaimed water in order to avoid water rights conflicts. Where IPR is proposed, generators and distributors of reclaimed water will need to work more closely with downstream users within a larger regulatory context to protect water supply quantity and quality. West Virginia No information was available from West Virginia at the time of publication.

5.2.2.5 Context and Drivers of Water Reuse

Virginia One of the longest operating and successful reclamation projects in the country was initiated in

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1978 by the UOSA. UOSA was created to provide regional collection and advanced treatment of wastewater generated from multiple small communities, many with inadequate wastewater treatment facilities and failing individual septic systems. Project details are described in a case study [US-VA-Occoquan]. The UOSA discharge provides significant contributions to the Occoquan Reservoir, which is the raw water supply for Fairfax Water, a utility that provides potable water to northern Virginia. The UOSA system is also the longest operating planned surface water IPR project in the United States. Subsequent to the effective date of Virginia’s Water Reclamation and Reuse Regulation in October 2008, several new water reclamation and reuse projects were authorized. These included, among others, the following projects: 

The Broad Run WRF in Loudoun County is permitted to produce 11 mgd (482 L/s) of Level 1 reclaimed water (secondary treatment, filtration, and higher level disinfection) for a variety of uses including turf and landscape irrigation; toilet flushing; fire fighting and protection; and evaporative cooling, primarily at data centers.



The Noman Cole, Jr. Pollution Control Plant in Fairfax County is permitted to produce 6.6 mgd (289 L/s) of Level 1 reclaimed water. A portion of this water is delivered to an energy resource recovery facility for cooling, boiler blowdown and washdown and to the Fairfax County Park Authority for irrigation of a golf course, recreation area, and park.



The Parham Landing WWTP in New Kent County is permitted to produce 2.0 mgd (88 L/s) of Level 1 reclaimed water. A portion of this water is delivered to two golf courses for irrigation and to a horse racing track for irrigation and dust suppression.



The Bedford City WWTP in Bedford County is permitted to produce 2.0 mgd (88 L/s) of Level 2 reclaimed water (secondary treatment and standard disinfection). A portion of this water is delivered to a food packaging facility for cooling.

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Chapter 5 | Regional Variations in Water Reuse



The Maple Avenue WWTP in Halifax County is permitted to produce 1.0 mgd (43 L/s) of Level 2 reclaimed water. Most of this water will be delivered to a wood-burning power producer for cooling and boiler feed.

Other projects that have been grandfathered until they expand their reclaimed water production or distribution capacity include the Proctors Creek Wastewater Treatment Facility (WWTF) and the Remington WWTF in Chesterfield and Fauquier Counties, respectively. Both facilities provide treated effluent of quality better than or equal to Level 2 reclaimed water to coalburning power generation facilities for cooling or stack scrubbing (Bennett, 2010). Delaware Delaware has a long history of promoting reuse of reclaimed water. Some fields in Delaware have been receiving reclaimed water since the 1970s with no adverse effects to the fields, crop yields, or the water table beneath the field. As previously mentioned, there are 23 facilities permitted in Delaware that use reclaimed water largely for agricultural irrigation as well as to irrigate two golf courses and several tracks of wooded land. District of Columbia While many facilities in the District of Columbia are practicing graywater use, only one water reuse project has been implemented to date. The Sidwell Friends Middle School campus was recently renovated for LEED Platinum certification, including on-site water reuse, as described in the associated case study [USDC-Sidwell Friends]. The University of the District of Columbia is similarly considering on-site water reuse for its campus and is working with District of Columbia Water and Sewer Authority (D.C. Water), the District Department of the Environment, and the Department of Health to develop the potential project. Pennsylvania In Pennsylvania, an advanced treatment facility provides reclaimed water for Pennsylvania State University and the surrounding area from the Spring Creek Pollution Control Facility. Treatment includes activated sludge with biological nutrient removal (BNR) followed by diversion to the reclamation facilities consisting of MF/RO and UV disinfection with sodium hypochlorite added to a 1.5 million gallon storage tank serving the distribution system (Smith and Wert,

2012 Guidelines for Water Reuse

2007). Other projects include dust control and toilet/ urinal flushing (Grantville and Pittsburg Convention Center) and the Falling Water garden in Mill Run, Pa. (Vandertulip and Pype, 2009 and [US-PA-Mill Run]. In Kutztown, the Rodale Institute has installed a water reclamation system as part of its Water Purification Eco-Center. The project highlights water reuse as an alternative to traditional sewage management for a broad audience, including elementary school children, municipal officials, land developers, watershed management groups, planning commissioners, policy makers, and environmental enforcement officers [USPA-Kutztown]. Although interior residential reuse would not be permitted under current guidelines, Hundredfold Farm in Adams County was the first rural cohousing community in Pennsylvania and uses their treated wastewater for toilet flushing as well as irrigation. There are also 11 industrial establishments and 14 municipal treatment plants that use their treated wastewater for irrigation purposes. Maryland Maryland has 35 spray irrigation systems using reclaimed water, with the largest being 0.75 mgd (32 L/s). The majority of the systems are for agricultural irrigation. Nine of the spray irrigation systems are for golf course irrigation. Other reuse systems included four rapid infiltration systems, two overland flow, and three drip irrigation systems (Tien, 2010).

5.2.3 Southeast: Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee This section focuses on the regulatory context and drivers for water reuse in eight states in the Southeast.

5.2.3.1 Population and Land Use The Southeast is one of the most populous and fastest growing regions in the United States. With nearly 19 million people, Florida is the most populous of the southeastern states. It is followed by Georgia and North Carolina, each with approximately 10 million residents, and then Tennessee with over 6 million people. Historically, the Southeast states have relied heavily on agriculture. However, in the last few decades, the region has become more urban and industrialized. Despite this development, some southeastern states still have not implemented sophisticated reuse programs. Florida, however, has one of the largest reuse programs in the country. A factor that has contributed greatly to the significant

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Chapter 5 | Regional Variations in Water Reuse

Percent Change

Florida

6.0

Georgia

5.0

Kentucky

4.0

Mississippi

3.0

North Carolina

2.0

South Carolina

1.0

Tennessee

Dec

Oct

Nov

Sept

Jul

Aug

Jun

Apr

May

Mar

Jan

Month

11.2

12.0

Figure 5-10 Average monthly precipitation in the Southeast region

9.7 Southeast Region

8.0 5.7

6.0

US

4.0 2.0 0.0

Population

Land Use

Figure 5-9 Change in population (2000-2010) and developed land (1997-2007) in the Southeast region, compared to the United States

Florida experienced huge growth in population from 1980 to 2010 (93 percent increase), and with that came a dramatic increase in developed land at nearly 100 percent over what it was in 1982. Georgia, North Carolina, South Carolina, and Tennessee likewise saw population growth exceeding the national average. In these states, population growth likewise corresponded to an increase in developed land exceeding the national rate. Because of this stress from growth and development, Florida and some of the other southeastern states, particularly in the large urban centers, present huge opportunities for reuse.

5.2.3.2 Precipitation and Climate The predominate climate in the Southeast is humid subtropical with a small area of wet/dry-season tropical zone in South Florida. Compared to the rest of the country, states in the Southeast get the most average rainfall, with close to or above 50 in (127 cm) per year. Yet, it may be surprising that Florida has probably the most reuse flow going to landscape irrigation at 360 3 million gallons per day (403,200 ac-ft/yr) (15.8 m /s) than any other state. Part of the explanation lies in an initial regulatory driver to reuse instead of increasing 5-16

Alabama

7.0

0.0 14.7

14.0

10.0

8.0

Feb

16.0

deep well disposal. Figure 5-10 depicts typical monthly precipitation in the Southeast by state.

Average Rainfall (inches)

development of reuse in Florida and the Southeast is the significant increase in urbanization of the states’ major population centers and in the land use surrounding those centers. As population increases, particularly in coastal areas, water resources are stressed, and water reuse becomes an integral part of meeting the projected future water demand. Figure 5-9 compares the percent change in population in the Southeast region to the entire United States from 2000 to 2010 and percent change in developed land coverage from 1997 to 2007.

It is clear that the springtime rainy season in the Southeast occurs in March, which is the wettest time for most of the southeast states. However, Florida’s wettest season is during the summer months. For irrigation uses, this rainy cycle during the best growing months creates a disconnect between the supply and demand rates of reclaimed water for urban and agriculture reuse programs. This must be solved through the use of seasonal storage (tanks, lakes, aquifer storage, and recovery wells), diversification of the reuse program (bulk interruptible users, large industrial users, aquifer recharge, etc.), development of supplemental water sources, by permitting a limited wet-weather discharge, or by having a permitted backup disposal option such as deep well injection or surface water discharge.

5.2.3.3 Water Use by Sector The opportunities for water reuse differ somewhat among the Southeast states. All of the states have large opportunities for water reuse in the energy sector. In Florida and Mississippi, irrigation demand also provides a large opportunity for reuse. Figure 5-11 shows freshwater use by sector in the Southeast.

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Chapter 5 | Regional Variations in Water Reuse

Public supply 12%

Domestic selfsupply 1%

Irrigation 11% Thermoelectric 67%

Livestock 1% Aquaculture 2% Industrial 5% Mining 1%

Figure 5-11 Freshwater use by sector for the Southeast region

While irrigation does not seem to present a huge opportunity for reuse in Alabama, South Carolina, and Tennessee, the use of reclaimed water for irrigation in certain circumstances (e.g., where irrigated hayfields or golf courses are located next to a domestic WWTF) in these states should not be overlooked. Likewise, in Florida and Mississippi, where the use of freshwater in the energy sector is largely overshadowed by reuse for irrigation, the use of reclaimed water in cooling towers and other uses at thermoelectric power plants can be a huge local opportunity for reuse in areas where those plants are located. In Florida, power plants can be a reuse utility’s largest bulk customer. In many parts of Florida, reclaimed water is an integral part of the water supply portfolio, and this trend is expected to continue. With limited freshwater in many areas, reclaimed water has allowed communities to grow and has reduced the need for development of other alternatives. Irrigation demands in Florida are second only to Arkansas. This may partly explain why Florida’s most popular use of reclaimed water (68 percent of the total reuse flow) is irrigation (public access areas, 58 percent, and agricultural irrigation 10 percent) (FDEP, 2012a). Farming is the largest industry in Florida, and the use of surface water and groundwater sources for irrigation remain significant withdrawals of the freshwater supply in the state. There are two main impeding factors to expanding the use of reclaimed water for agricultural activities: negative perception of reclaimed water by farmers and their customers, and the rural nature of farmland, which means that there are high financial and energy

2012 Guidelines for Water Reuse

costs to supply reclaimed water to these areas. The public use of water is also huge and indicates a big opportunity for aquifer recharge and potable reuse; however, this represents the most stringent level of treatment and most potential for public resistance. Florida is not a center of heavy industry, and as a result, industry is the smallest of the water uses in Florida. Leading industries include food processing, electric and electronic equipment, transportation equipment, and chemicals. While the industrial and energy sectors are not huge parts of the total water use in Florida, the opportunities presented by these industries, particularly in the towns where large industrial facilities and power plants are located, are desirable to reclaimed water providers. Alabama, Georgia, Mississippi, South Carolina, and Tennessee all have higher industrial water use demands that are in the range of 5 to10 percent. Potable Water Availability and Rates With the exception of Florida, Arkansas, and Mississippi, the majority of freshwater withdrawn in the Southeast comes from surface water sources. In Florida, nearly 90 percent of the potable water is supplied by groundwater. Potable water rates are still relatively cheap due to the low cost of production (very little treatment required). However, in some parts of the state, particularly in the Tampa Bay area and Southeast parts of the state and along the coastline in the Northeast and parts of the Panhandle, the aquifers are stressed. In these stressed areas, called Water Resource Caution Areas by state statutes, potable water rates may be higher and may be a better reflection of the real cost of providing water. Within these Water Resource Caution areas, investigating the feasibility of reuse programs is mandated, and utilities (water supply and wastewater management) as well as water users must implement reuse to the extent that is determined to be feasible. Potable water rates in several municipalities surveyed in Florida in 2003 ranged from a low of $0.50/1,000 gallons ($0.13/1000 L) to a high of more than $10.00/1,000 gallons ($2.64/1000 L), depending on the gallon usage (tiered rate); however, for most residential uses the average potable water rate was around $1.50/1,000 gallons ($0.40/1,000 L) (Whitcomb, 2005). (See also Table 7-1 for sample rates.) Note that as utilities in Florida adopt conservation rate structures, potable water rates have

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increased above these 2003 values. Reclaimed water rates in the same year in Florida were very competitive, ranging from $0.19 to $5.42/1,000 gallons ($0.05 to $1.43/1,000 L) for residential customers and from $0.05 to $18.30/1,000 gallons ($0.01 to $4.83/1,000 L) for non-residential customers (FDEP, 2012a). Except for a few isolated instances, water in the southeastern states is generally undervalued, therefore inhibiting the perceived need for water reuse.

5.2.3.4. States’ Regulatory Context

Alabama, Georgia, Kentucky, Mississippi, South Carolina, and Tennessee Alabama and Georgia each have guidelines governing various aspects of reuse. Kentucky does not have regulations or guidelines governing reuse. Mississippi has regulations that cover the potential for reclaimed water to be reused for restricted urban reuse, agricultural reuse for non-food crops, and industrial reuse. South Carolina has regulations governing reuse that stipulate that wastewater facilities that apply to discharge to surface waters must conduct an alternatives analysis to demonstrate that water reuse is not economically or technologically reasonable. Tennessee allows reclaimed water to be distributed for land application reuse by industrial customers, commercial developments, golf courses, recreational areas, residential developments, and other nonpotable uses. Implementation of reuse programs are through the NPDES or state operating permit programs with additional requirements for reuse that are specified in the permits. Tennessee guidelines for reuse include the Design Guidelines for Wastewater Treatment Systems Using Spray Irrigation. Florida Florida has one of the more mature water reuse programs that continues to evolve with new environmental and regulatory drivers. Florida leads the United States with 49 percent of treated wastewater reclaimed and reused (FDEP, 2012a). The reuse capacity in the state is higher—up to 64 percent of the state’s permitted domestic wastewater capacity is dedicated to reuse. In 2006, FDEP’s Water Reuse Program was the first recipient of the EPA Water Efficiency Leader Award. However, Florida realizes only a fraction of reuse opportunities. In 2011, a total of 57 large domestic wastewater treatment facilities did not provide reuse of any kind. This unused capacity presents a potential to expand the availability of reclaimed water in the state. The 2008 Legislature

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enacted laws that prohibit ocean discharge of treated wastewater by 2025 except as a backup to a reuse system. Sixty percent of the water currently discharged in ocean outfalls will have to be reused for a beneficial purpose, increasing reclaimed water use by at least 3 180 mgd (7.9 m /s) by 2025. The 2007 to 2008 droughts highlighted the need to use all sources of water efficiently. In lieu of new legislation considered in 2008, FDEP initiated three workshops to gather input on water reuse issues and goals for Florida. Meeting attendees included representatives from the FDEP, the five water management districts, local government, utilities, and other parties with an interest in reuse. Issues discussed included regulatory authority, offsets, irrigation, supplementation (augmentation), funding, optimization of reclaimed water resources; mandatory reuse zones, communication and coordination, and reuse feasibility study preparation. The regulatory authority may be the result of increased value seen in reclaimed water with utilities believing that they should control the resource that they spend money to create, cities wanting some control, and water management districts believing reclaimed water falls under the legislative grant of jurisdiction to regulate the consumptive use of water. Another interesting issue is the discussion on supplementation, which is also referred to as augmentation. In most instances, augmentation is the addition of highly treated reclaimed water to a surface water body or aquifer for IPR. In Florida, for some utilities, the opportunity to supplement reclaimed water with other water sources helps promote a higher percentage use of reclaimed water because it makes availability to a larger number of users more reliable. However, some environmental organizations and other local governments have expressed concern over this practice. For more information, consult the FDEP Connecting Reuse and Water Use: A Report of the Reuse Stakeholders Meetings (FDEP, 2009). An outcome of these workshops was the establishment of a reclaimed water workgroup consisting of representatives from the same stakeholders. After the first three workshops, the workgroup continued to meet almost monthly for three years, coming to some kind of consensus on these issues. The workgroup’s efforts resulted in statutory changes, rule changes, and increased coordination among stakeholders. The workgroup’s final report was published in May 2012.

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Chapter 5 | Regional Variations in Water Reuse

North Carolina Reclaimed water systems are classified in North Carolina as either conjunctive or non-conjunctive systems. A conjunctive reclaimed water system refers to a system where beneficial use of reclaimed water is an option and reuse is not necessary to meet the wastewater disposal needs of the facility. In this case, other wastewater utilization or disposal methods (i.e., NPDES permit) are available to the facility at all times. A non-conjunctive reclaimed water system typically has evolved from land disposal system permits and refers to a system where the reclaimed water utilization option is required (or dedicated) to meet the wastewater disposal needs of the facility and no other disposal or utilization options are available. Of the 128 active reclaimed water permits in North Carolina, approximately 48 percent are for conjunctive use systems and approximately 64 percent of those are from municipalities. Changes in the North Carolina regulations now allow more flexibility for utilities to expand use beyond dedicated land disposal in the remaining non-conjunctive permits. The projected increase in reclaimed water demand due to the rule changes were estimated based on newly approved uses of food crop irrigation, wetlands augmentation, residential conjunctive drip irrigation systems, and the estimated increase in residential irrigation demand (NCAC, 2011).

5.2.3.5 Context and Drivers of Water Reuse

Alabama In Foley, Ala., model studies and a constructed wetland/percolation pond were studied at 20,000 gpd (0.9 L/ s) flow rate using secondary treatment effluent as feed to confirm application for groundwater recharge in the future. Georgia Water reuse in Georgia varies from constructed wetlands to augment shallow aquifers and spring flow to creeks, to landscape irrigation, and even flushing urinals and toilets in permitted buildings. Two case studies [US-GA-Clayton County] and [US-GA-Forsyth County] highlight the state’s success in augmenting surface water supplies and offsetting potable water demands within the state. Historically, water reuse has been limited in Georgia due to perceived adequate rainfall and water resources. This perception began to change during an intense drought period in 2007 and 2008, after which

2012 Guidelines for Water Reuse

many communities re-evaluated how they would meet future water supply needs if a lack of rainfall persisted. In Coastal Georgia specifically, the 2007 and 2008 drought period only compounded the already occurring issue of overproduction of drinking wells in the area, which was resulting in saltwater intrusion of coastal aquifers. In fact, the Georgia Environmental Protection Division (GEPD) had already developed a Coastal Georgia Water and Wastewater Permitting Plan for Managing Salt Water Intrusion (2006 Coastal Plan) that required a non-agricultural groundwater permittee to develop a Water Reuse Feasibility Plan. The primary focus of the plan is halting the intrusion of salt water into the Upper Floridan aquifer (GEPD, 2007). The recommended uses for reuse water in Georgia were further expanded when on January 1, 2011; the Georgia Plumbing Code was amended to allow reclaimed water to be used for toilet and urinal flushing and for other approved uses in buildings where occupants do not have access to plumbing. This amendment to the plumbing code helped provide the framework to facilitate the use of reclaimed water in buildings in LEED-certification endeavors. Another driver for increasing water reuse in Georgia was a federal court decision affecting the use of Lake Lanier, a reservoir in the northern portion of the state that supplies water to many metro-Atlanta communities and other nearby communities. Lake Lanier is the uppermost of four major water bodies along the Chattahoochee River system that runs from the North Georgia Mountains, through Atlanta, Ga., Columbus, Ga., and the Florida Panhandle, and eventually discharges to the Gulf of Mexico. Lake Lanier has been the subject of water rights disputes among Georgia, Alabama, and Florida for more than two decades. A federal court decision on July 17, 2009, ruled that Lake Lanier was not authorized as a water supply reservoir, which meant that metro Atlanta would have to find another source of drinking water unless a political solution could be achieved. In response, the governor created a Water Contingency Planning Task Force that included elected officials, consultants, and representatives from several communities to conduct feasibility planning to determine the impact of the ruling and discuss methods of managing water resources in North Georgia if the ruling stood (Georgia Governor’s Office, 2009).

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Chapter 5 | Regional Variations in Water Reuse

As part of the response, the Metropolitan North Georgia Water Planning District developed a water management plan identifying options and concluded that alternative sources could not be developed by the 2012 deadline in the ruling. The plan acknowledged that unplanned indirect potable reuse was already occurring by augmenting the supply of Lake Lanier and Lake Allatoona with high quality reclaimed water and capture of upstream discharges comingled in the river. The Clayton County Water Authority [US-GAClayton County] project was identified as a planned indirect potable reuse project. Several established nonpotable reuse projects were also acknowledged. On June 28, 2011, the 11th Circuit Court of Appeals overturned the July 2009 court decision, finding that Lake Lanier was created as a water supply reservoir and directed the USACE to prepare a water allocation plan for Lake Lanier, after which both Alabama and Florida appealed. On June 25, 2012 the U.S. Supreme Court denied a request by Alabama and Florida for a review of the water case. While there will likely be more to this issue, it is serving as a driver for Georgia’s communities to integrate water reuse options into their regional water planning. Florida According to Florida’s 2011 Annual Reuse Inventory, the state has a total of 487 domestic wastewater treatment facilities with permitted capacities of 0.1 mgd (4.4 L/ s) or above that make reclaimed water available for reuse. These treatment facilities serve 3 434 reuse systems, where 722 mgd (31.6 m / s) of reclaimed water from these facilities is reused for beneficial purposes. The total reuse capacity associated with these systems is 2,336 mgd (102.3 3 m / s), which is 64 percent of the total capacity of domestic wastewater treatment facilities in the state and more than three times larger than the state’s reuse capacity in 1986 (FDEP, 2012a). Figure 5-12 shows the type of reuse that is occurring in Florida. To date, percentage of reuse by category of application is only available for Florida and California, states that compile the information.

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Agriculture Irrigation 10%

Groundwater Recharge 11%

Industrial Uses 16%

Public Access Areas 58%

Wetlands and Other 5%

Figure 5-12 Water reuse in Florida by type (FDEP, 2012)

Figure 5-13 depicts the large population centers in Florida where reuse has the largest opportunity for growth. The statewide per capita usage based on 2011 population estimates and total reclaimed water utilization in 2011 was 38 gpd (143.8 L/day) of reuse per person in Florida. The Orlando-Tampa metropolitan area averages well over 50 gpd (189 L/day) per person, while Miami-Dade and Jacksonville Metropolitan areas average 7 and 10 gpd (26.5 and 37.9 L/day) per person, respectively (FDEP, 2011). A future water quality issue that numerous stakeholder groups, including water resources utilities, have been watching in the state of Florida is the development of Numeric Nutrient Criteria (NNC). The national NNC dialogue began in 1998 with EPA’s National Nutrient Strategy that detailed the approach EPA envisioned “in developing nutrient information and working with states and tribes to adopt nutrient criteria as part of their water quality standards.” (EPA, 2007)

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Chapter 5 | Regional Variations in Water Reuse

Per Capita Reuse Flow 2011 State Average = 38.19 gpd/person

Over 50 gpd/person Between 15 and 50 gpd/person Below 15 gpd/person Top 10 most populous counties Note: Calculations of reuse flow per capita includes population that is served by onsite sewage treatment and disposal systems (e.g., septic systems).

Figure 5-13 Map of per capita reuse flow by county in Florida (FDEP, 2012)

Working in partnership with EPA, FDEP established a Technical Advisory Committee in January 2003 and began development of state criteria. In 2008, a federal legal and rulemaking process ensued, which led to EPA developing their own freshwater NNC in 2010 and working towards proposing rules for primarily marine waters in 2012. Additionally in 2012, the FDEP NNC passed through the state rulemaking and legal process, and that rule has been submitted to EPA for review. It is still uncertain whether the federal or state led NNC rulemaking process will eventually evolve into the NNC rule that will be implemented in the state of Florida. Interested parties should stay tuned to both the federal and state processes to track important milestones over the coming year (EPA, n.d.; FDEP, 2012b; FR 77, 2012:13496-13499). Unrelated to NNC, the 2008 legislature enacted laws that prohibit ocean discharge of treated wastewater by 2025 except as a backup to a reuse system. Sixty percent of the water currently discharged in ocean outfalls will have to be reused for a beneficial purpose, increasing reclaimed water use by at least 180 mgd 3 (7.9 m /s) by 2025. These requirements are based in part on reducing nutrient load to the coastal waters (Goldenberg et al., 2009).

2012 Guidelines for Water Reuse

North Carolina North Carolina is the sixth fastest growing state in the United States, especially in the Research Triangle area, because of the benefits and popularity of the area. This growth increases the need for planning and timely response to meet growing resource demands. Recognition of this growth allows planners to consider an integrated water management approach to their water, wastewater, and reclaimed water utilities. Climate change, recurring drought cycles, and increasing local temperatures result in an increase in irrigation demand to meet crop evaporation rates. At the same time, changes in precipitation patterns are causing planners to reassess previous plans. Even if the annual rainfall remains relatively constant, higher intensity rainfall can result in more runoff that is not as beneficial as multiple, less intense events. Shifts in time of year for rainfall events can significantly impact soil moisture during critical planting and harvesting periods. This can lead to an increase in supplemental irrigation for predictable crop yields. Recent changes in the North Carolina Reclaimed Water Regulations treat reclaimed water as a resource, allow many uses of reclaimed water by regulation, and increase the potential to use reclaimed water in agricultural applications, especially with Type 2 reclaimed water, the higher of two defined reuse qualities (NCAC, 2011). This higher quality reclaimed water has few agricultural restrictions (one being a 24-hour waiting period following application of reclaimed water prior to harvest). These new rules allow utilities to now consider wholesale supply of reclaimed water to agricultural interest, assuming both parties can come to agreement regarding the value of this water. Although there may not yet be large power generating needs for reclaimed water in North Carolina, cooling water and industrial process water are attractive to industries and can be supportive of economic development for a community. New residential developments in communities facing water shortages are often able to develop and provide a benefit to residents if reclaimed water is included in a dual water system, allowing homeowners to establish landscape without water restrictions increasing their water bills or use restrictions negating their landscape investments. In North Carolina today, nutrient reduction requirements and TMDLs resulting in new or re-issued discharge permits that will require installation of

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advanced wastewater treatment to meet limit of technology nutrient removal are much like events in 1972 that led to the creation of the dual-piped reclaimed water system for St. Petersburg, Fla. The Wilson-Grizzle Act was passed by the Florida legislature in 1972. It required all utilities to cease discharge into Tampa Bay unless they installed advanced wastewater treatment equipment to meet nutrient reduction requirements. Today, St. Petersburg is known as the largest residential reclaimed water service provider in the United States (Crook, 2005). This same opportunity to develop dual piped water systems for new developments could increase use of reclaimed water for residential irrigation over time, minimize increased demands on the potable water system, and delay or eliminate costly nutrient removal improvements at WWTPs. Going green (or, in some cases, gray) is sometimes driven by new development decisions to create a LEED-certified development or building. In the certification process, up to 10 points can be obtained through use of reclaimed water or on-site use of alternate waters. Currently in North Carolina, the use of graywater without treatment is not allowed (15A NCAC 18A); however, 2011 Session law has called for the development of graywater reuse rules to facilitate its safe and beneficial use. Currently, state/local plumbing authorities allow for the use of graywater for toilet flushing. Both national plumbing codes (Uniform Plumbing Code and International Plumbing Code) require use of purple pipe for all alternate water onsite. Alternate water is defined as reclaimed water, harvested rainwater, graywater, stormwater, and air conditioning condensate. This can create some confusion if a utility provides reclaimed water to a new development that also has alternate waters with some or no treatment. The town of Cary has one of the more established reclaimed water systems in North Carolina, starting in 2001 with 9 mi of distribution pipeline from the North Cary WRF serving 350 customers (Miles, et al., 2003; The Town of Cary, n.d.; and [US-NC-Cary]). The town also provided a central bulk fill station at the North Cary WRF as shown in Figure 5-14. Since system inception, town staff members have trained over 800 bulk water users, mainly landscape and irrigation contractors, in the proper use of reclaimed water. This training is required in order to obtain and apply bulk reclaimed water from the WRF. A recent industry

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article identified the Cary reclaimed water as “Purple…the new Gold” by serving as a resource during the drought to maintain landscape (Westmiller, 2010).

Figure 5-14 Cary, N.C., bulk fill station allows approved contractors, landscapers, and town staff to use reclaimed water

Durham County, N.C., expanded its reclaimed water program with storage, plant improvements, and a new distribution and metering system to supply supplemental reclaimed water to the town of Cary to begin service to the Cary West Reclaimed Water Service Area. Improvements at the County’s Triangle WWTP included a 400,000-gallon ground storage tank, a new high-service reclaimed water distribution pump station, a bulk liquid chlorine feed system, a 24/20/16-in distribution system to serve the town of Cary and other county demands, and a town of Cary metering station. The city of Raleigh Public Utilities Department currently manages two reclaimed water distribution systems (City of Raleigh, 2012). One is located in the Zebulon service area and currently serves seven customers, totaling approximately 36 million gallons 3 (1.6 m /s) annually. The larger Southeast Raleigh reclaimed water distribution system from the Neuse River WWTP is being extended to serve the Walnut Creek Environmental Education Center and the North Carolina State NCSU Centennial Campus and Poole Golf Course. Raleigh has four bulk reclaimed water stations located throughout the service area at the Neuse River WWTP (southeast Raleigh), E. M. Johnson Water Treatment Plant (North Raleigh), Little Creek WWTP (Zebulon), and Smith Creek WWTP (Wake Forest). Bulk

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Chapter 5 | Regional Variations in Water Reuse

reclaimed water is free of charge after a user completes certification training by the Public Utilities Department. Uses for bulk reclaimed water include irrigation, hydro-seeding, pesticide and herbicide application, concrete production, power/pressure washing, and dust control. There is also a small on-site reclaimed water system in Wilkerson Park in the city of Raleigh. Wastewater is collected, treated, and reused on-site under a permit issued by the local health department. The University of North Carolina (UNC) at Chapel Hill began addressing high water use a decade ago with traditional water conservation efforts (low flow showerheads, faucet aerators, and dual flush toilets) and by creating closed loop water service to research laboratories resulting in a 27 percent reduction in water use per square foot. More stringent stormwater regulations in the town of Chapel Hill and Jordan Lake nutrient reductions imposed by the state led to rainwater harvesting on the UNC campus. Harvested rainwater and stormwater is stored in cisterns (constructed under playing fields) and used for irrigating the soccer/intramural fields and baseball stadium, landscaping, and toilet flushing. Two 100year drought events within 7 years led to the addition of reclaimed water to support campus activities in 2009. Five interconnected chilled water plants (50,000 ton capacity) on campus use 0.5 mgd (21.9 L/s). The UNC Hospital chiller plant uses an additional 0.2 mgd (8.8 L/s). The football and baseball fields are supplied with 0.03 mgd (1.3 L/s) of reclaimed water. Utilization of reclaimed water for uses previously provided potable water reduced potable water use by 37 percent. Finally, to increase system reliability and diversify supply, the rainwater/stormwater cistern system was provided with supply connections from the reclaimed water system (Elfland, 2010). South Carolina Water reuse is governed under the state land application rules and is most common along the coast via golf course irrigation. Where controlled access is part of the program, secondary treatment is acceptable. If a more publicly-accessible site is to be used, higher levels of treatment would be required. Some small towns use land application in lieu of surface water discharge in areas where land is inexpensive to purchase. A primary focus of land application permitting is groundwater protection.

2012 Guidelines for Water Reuse

Therefore, the higher the level of treatment and the greater the depth to groundwater, the more flexible a permit can be written. Tennessee Water reuse occurs throughout the state of Tennessee, including in Cumberland, Fayette, Franklin, Lawrence, Maury, Moore, Rutherford, Washington, Williamson, and White counties. Most reuse is for irrigation of golf courses, followed by irrigation for pasture land, residential areas, and parks. Reuse systems in Tennessee operate under a State Operation Permit issued by the Tennessee Department of Environment and Conservation’s Division of Water Pollution Control. None of the existing facilities, however, use the reclaimed water for edible crop irrigation, groundwater recharge, or IPR applications. One case study in Tennessee highlights the importance of reuse in integrated planning as a means to address nutrient loading limits to a receiving stream as a result of urban growth [US-TN-Franklin].

5.2.4 Midwest and Great Lakes: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, Ohio, and Wisconsin This section focuses on the regulatory context and drivers for water reuse in 10 states in the Midwest and Great Lakes region.

5.2.4.1 Population and Land Use According to the 2010 United States Census, the population in the Midwest and Great Lakes Regions is around 65 million. The geographic center of the contiguous United States is found in Kansas. Chicago, Ill. and its suburbs form the largest metropolitan area in the Midwest, followed by Detroit, Mich.; the Twin Cities (Minneapolis and St. Paul, Minn.); Cleveland, Ohio; St. Louis, Mo. and the Kansas City, Mo. area. Figure 5-15 shows change in population in the Midwest in the past decade, relative to the United States. The figure also shows the percent change in developed land coverage from 1997-2007.

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12.0 9.7

8.0

6.9 5.7

6.0

US

3.9

2.0

Illinois

4.0

Michigan

3.5 3.0

Minnesota

2.5

Ohio

2.0

Wisconsin

1.5

Iowa

1.0

Kansas

0.5

Missouri

Population

Land Use

Figure 5-15 Change in population (2000-2010) and developed land (1997-2007) in the Midwest and Great Lakes region, compared to the United States

Nebraska

Dec

Oct

Nov

Sept

Jul

Aug

Jun

May

0.0

Apr

Jan

0.0 Mar

4.0

Midwest and Great Lakes Regions

Illinois

4.5

Feb

Percent Change

10.0

Average Rainfall (inches)

5.0

Month

Figure 5-16 Average monthly precipitation in the Midwest

5.2.4.3 Water Use by Sector 5.2.4.2 Precipitation and Climate The Midwest states have varying hydrologic and climatic conditions that impact water use. The differences in population and land use in each state also affect consideration of reclaimed water over traditional water supplies. Common to most of the Midwest is a larger proportion of agricultural land and related agricultural processing industries. There are also heavy industrial areas that include mining, auto manufacturing, refining, and metal finishing. The vast central area of the United States, located between the Central Atlantic coastal states and the Interior Plains states just east of the Rockies, is a landscape of low, flat to rolling terrain typified by vast acres of farmland largely affected by the Mississippi River Drainage System, as well as by the Missouri and Ohio Rivers and the Great Lakes. Rainfall decreases from east to west across the region. Much of the Midwest experiences a humid continental climate, which is typified by large seasonal temperature differences—warm to hot (and often humid) summers and cold (sometimes severely cold) winters. This region of the country is known for extreme weather events: floods in the winter and spring and droughts in the summer months. Figure 5-16 depicts average monthly precipitation in the Midwest region by state.

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Figure 5-17 shows freshwater use by sector in the Midwest and Great Lakes Region.

Public supply 10%

Domestic selfsupply 1%

Irrigation 17% Thermoelectric 63%

Livestock 1% Aquaculture 1% Industrial 5%

Mining 2%

Figure 5-17 Freshwater use by sector for the Midwest and Great Lakes region

Given the different climatic regions and types of industry in the Midwest, water use varies among states. One common use for states with larger river sources such as the Mississippi, Missouri, and Ohio Rivers is the non-consumptive use for once-through cooling water at power generation facilities. This water use is not the optimum candidate for reclaimed water since it does not replace a consumed supply of groundwater or surface water, as would be the case for power plants with recirculated cooling systems. Lower effluent limit requirements being set for some municipal dischargers is expected to result in more

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Chapter 5 | Regional Variations in Water Reuse

municipal wastewater facilities considering water reuse for future improvements projects.

More than 60 percent of the water used in Minnesota is for power generation facilities, mainly for oncethrough cooling, as depicted in Figure 5-18. Power generation facilities are supplied mostly by surface waters.

Industrial 12%

Public Potable Water Supply 16% Other 1% Irrigation 10%

Power Generation 61%

Figure 5-18 Water use in Minnesota, 2007 (Source: MDNR 2008)

The next largest use of water, around 16 percent of the total, is for potable water supply (water utilities), distributed by municipalities for domestic, commercial and industrial uses. Nearly two-thirds of the potable water in Minnesota is supplied by groundwater, as shown in Figure 5-19.

600

2007 Water Use, mgd

An analysis of one state, Minnesota, is provided as a perspective on water use in other Midwest states.

700

500

*power generation not included

400 Surface

300

Ground

200 100 0

Public Industrial potable water supply

Irrigation

Other

Figure 5-19 Water use in Minnesota by source*, 2007 (Source: MDNR 2008)

Water withdrawn by industries (those not served by water utilities) for various processing needs accounts for about 12 percent of the total water used in Minnesota. The majority of this is surface water used by the pulp and paper and mining industries. Agricultural processing accounts for the largest use of groundwater by industry. Irrigation accounts for about 9 percent of the total water used, and all other water uses comprise about 4 percent of the total water use. Like many Midwest states, the larger users of groundwater in Minnesota are not always in proximity to populated areas with a sufficient reclaimed water supply, notably for agricultural irrigation and processing facilities. In 2005, the total industrial water use in Minnesota, excluding surface water supplies for power facilities, was estimated to be 445 mgd (19.5 3 3 m /s), of which 75 mgd (3.3 m /s) was used by industries in the Twin Cities area. The total WWTF 3 discharge for the state is 425 mgd (18.6 m /s), and 3 255 mgd (11.2 m /s) is from WWTFs in the Twin Cities (Metropolitan Council Environmental Services, 2007).

5.2.4.4. States’ Regulatory Context The Midwest states are beginning to develop regulations and guidelines for water reuse, prompted by recent water reuse installations motivated by shrinking water supplies and other factors. Illinois, Indiana, Iowa, Michigan, Missouri, and Nebraska have water reuse regulations whereas Kansas, Minnesota, and Ohio have guidelines. Wisconsin currently does not have regulations or guidelines governing reuse.

2012 Guidelines for Water Reuse

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5.2.4.5 Context and Drivers of Water Reuse This section identifies drivers and characteristics that broadly apply to Midwest states with examples of current reuse practices and develops a range of considerations using Minnesota as an example. There are a variety of opportunities for broader implementation of water reuse practices in the Midwest. There are also a host of factors that affect the feasibility of reuse implementation. Water reuse practices in the Midwest are site-specific and based on a variety of drivers. The drivers can be grouped into four categories: water quality, water quantity, sustainable economic growth, and environmental stewardship (MCES, 2007). Water Quality A safe, cost-effective, and adequate water supply generally has been readily attained for most Midwest communities and industries. Historic water reuse applications have been water quality driven. Agricultural irrigation using treated wastewater effluent has been practiced in the Midwest’s rural areas in lieu of summer pond discharges for facilities a significant distance from an acceptable receiving stream. More recent water reuse applications driven by discharge limitations include golf course irrigation in urban and resort areas and toilet flush water for buildings. Water quality issues will drive future water reuse in the Midwest. As growing communities generate additional wastewater, there will be a need to provide higher levels of wastewater treatment to maintain or decrease discharge loads to the region’s waterways. The development of TMDLs in the Mississippi River basin’s sub watersheds will result in reduced effluent limits for phosphorus, solids, and total nitrogen for many municipal dischargers. Water reuse may become a cost-effective practice for communities where advanced treatment processes are required to meet new receiving stream discharge limits. If these communities are experiencing or forecasting water supply limitations, the benefits of a water reuse option could be even more pronounced. A new advanced WWTF in East Bethel, Minn. in the Twin Cities metro area will discharge high quality reclaimed water to rapid infiltration basins rather than discharging to the river. Water Quantity While water quality discharge limitations will increasingly be a factor in the Midwest, it is anticipated

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that water supply limitations will be a driver in the near future. There are regions and areas specific to each state with an insufficient quantity of ground or surface water and/or impaired quality from various pollution sources. In terms of water demand for crop irrigation, the northern plains states use 64 percent of total water withdrawals for agricultural irrigation, versus 14 percent for states to the east (Wu et al., 2009). This significant difference in water use is related to less precipitation in the northern plains states as well as a proportionately smaller population with a demand for municipal and power supply uses. The mid-2000s surge in the biofuel industry prompted investigations for water supply options other than local groundwater in the Midwest’s water supply limited regions. Ethanol facilities in North Dakota and Iowa are currently using reclaimed water. Limited groundwater supply was also the driver for using reclaimed water for a sand washing operation in Marshfield, Wis., and several power generation facilities, such as those supplied by the Heart of the Valley Metropolitan Sewerage District, Wis.; Clear Lake Sanitary District, Iowa; and Mankato, Minn. Sustainable Economic Growth Water has historically been undervalued in the Midwest. With the exception of local or sub-regional areas with limited supplies of adequate quality, residents of the Midwest typically pay less for their water supply than areas of the United States with higher levels of water reuse. While the past decades have focused on protecting the aquatic habitat of the Great Lakes resource and regional watersheds of the Mississippi River basin, future decades will increase efforts to protect ground and surface waters used for potable water supply. As observed with the surge of the biofuel industry, water demand for irrigation and industrial use already has exceeded or may at some point exceed the available groundwater supply in some areas. Communities that want to share in the economic gains of the industry need to be able to provide a sustainable water supply, and there may be more incentive to consider reclaimed water.

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

Environmental Stewardship Conservation has been a part of many states’ water protection programs, along with more stringent regulations for surface water dischargers. This stewardship ethic can drive reuse projects even when other drivers are not present and when economics would not point to reuse. For example, the Shakopee Mdewakanton Sioux (Dakota) Community’s (SMSC) 0.96 mgd (42 L/s) WRF, constructed in 2006, was initiated as part of SMSC’s ongoing activities toward self-sufficiency and natural resources protection. The community’s commitment to environmental stewardship is explained as follows: “The Dakota way is to plan for the Seventh Generation, to make sure that resources will be available in the future to sustain life for seven generations to come” (SMSC, n.d.). The facility, located in Prior Lake, Minn., is permitted to discharge to one of two wetlands, shown in Figure 5-20, with downstream ponded areas that provide water for SMSC’s golf course irrigation system. State and federal agencies are working with the SMSC to explore aquifer recharge to be used primarily in the winter when irrigation is not needed.

work, while preserving freshwater for additional uses. These 1,100 ac of wetlands provide habitat for migratory waterfowl and other wildlife. They are a very popular destination for bird watching and, in the fall, for duck hunting. Emerging Water Reuse Practices In some areas of the Midwest, additional emerging drivers may include augmenting or preserving both surface water supplies and groundwater supplies, power generation, and recreational/aesthetic reuse. In the Chicago metro area, significant flows from regional wastewater treatment pass through the Lockport Powerhouse. Built in 1907, the powerhouse is used by the Metropolitan Water Reclamation District of Greater Chicago to control the flow of the Sanitary and Ship Canal and limit the diversion of water from the Lake Michigan Watershed. The district received approximately $3 million of credit from Commonwealth Edison for transferring approximately 60 million kWhs of power safely generated through hydropower. On Chicago’s west side, a water reuse feasibility study was conducted for service in the vicinity of the Kirie WWTP. Three business/industrial parks in three separate villages are located near the plant, and O’Hare International Airport is to the southeast. Potential uses for reclaimed water to replace potable water use range from 1.3 to 1.9 mgd (57 to 83 L/s) based on the time of year. Potential uses include irrigation, cooling towers, industrial process water, stormwater basin cleaning, municipal solid waste truck washout, and wetland augmentation. In some Midwest communities, recreational or aesthetic reuse occurs in the form of using reclaimed water to augment golf course ponds, both landscape ponds and water hazard features. This may be indirectly augmenting golf course irrigation needs.

Figure 5-20 The SMSC WRF and wetlands

Reclaimed water from Columbia, Mo., is directed to a series of managed wetlands operated by the Missouri Department of Conservation. The wastewater is fed through a series of channels and gates, largely by gravity, offsetting water that would have to be pumped from the ground or the nearby Missouri River for the wetlands. This saves on electrical costs, allowing the scarce public money to be spent instead on habitat

2012 Guidelines for Water Reuse

The Village of Richmond, Ill., a small rural community west of Chicago, recently developed an ordinance to promote the preservation of rapidly shrinking groundwater supplies when other sources of water exist for specific uses. The ordinance describes specific instances where municipal water supply users would be required to use reclaimed water. The ordinance encourages water reuse in general. For example, industries are encouraged to use reclaimed water for nonpotable industrial processes. There are

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Chapter 5 | Regional Variations in Water Reuse

both mandated and recommended applications. The following applications are mandated uses: 

Landscape watering except in playgrounds



Landscape water features except in playgrounds frequented by children 10 years of age or under



Industrial cooling water



Toilet flushing at commercial, industrial, and public facilities



Commercial car wash facilities



Commercial, industrial, and public boiler feed water

The ordinance encourages other industrial users to consider reclaimed water for appropriate nonpotable industrial processes, specifically mentioning water for construction practices, commercial uses, enhancement of wildlife habitat, and recreation impoundments. Recently, the state of Missouri was approached about the reuse of treated wastewater in intensive agriculture. The proposals would use wastewater to grow cellulosic biofuel crops in fields specifically constructed with wastewater reuse in mind to maximize production. In instances where all of the wastewater generated by a small town can be used during the summer recreation season, rather than discharged to a water body, it may enable that town to avoid costly upgrades due to new water quality regulations. Water Reuse Practices in Minnesota Current Minnesota reuse projects include five for golf course irrigation, one for building toilet flush water, one for wetland enhancement, one for energy plant cooling water, and 32 for agricultural irrigation (non-food crops; main discharge for seasonal stabilization ponds). Limited water supply was the key driver for the largest water reuse application in Minnesota. The city of Mankato expanded its WWTF in 2006, shown in Figure 5-21, to provide the Mankato Energy Center, a 365-MW facility (ultimate capacity of 630 MW), with cooling water. The city provides up to 6.2 mgd (272 L/s) of reclaimed water to the Mankato Energy Center,

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which returns its cooling water discharge to the WWTF (approximately 25 percent of the volume supplied) as a permitted industrial discharger. The cooling water is commingled with the WWTF process stream prior to dechlorination. Refer to [US-MN-Mankato] for more details.

Figure 5-21 Mankato Water Reclamation Facility

Water supply scarcity in Minnesota’s southwest region affected the siting of ethanol facilities during the biofuel industry expansion of the mid-2000s. In conjunction with other planning activities, state agencies increased inventory research on groundwater resources and streamlined permitting practices. In addition, the state legislature became involved by supporting initiatives for water reuse, emphasizing the economic sustainability goals tied to water (MPCA, 2010a). Legislation under H.F. 1231 introduced in 2009 provided in-kind matching grants for capital projects incorporating water reuse, including specific funds targeting ethanol facilities. Water conservation legislation passed in 2008, based on environmental stewardship and conservation drivers, could affect how municipalities plan for their water supplies. Public water suppliers serving more than 1,000 people (85 percent of Twin Cities metro suppliers) must implement a water conservation rate structure. The rate structure was required by Twin Cities metro area suppliers by 2010, and all remaining water suppliers are to implement the conservation rate structure by 2013 (MPCA 2010b). Long-term planning for water reuse in Minnesota and other Midwest communities will be influenced by the

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

Implementation Considerations in Minnesota Minnesota is one of several states that have not developed state water reuse criteria. Currently, Minnesota uses California’s Water Recycling Criteria to evaluate water reuse projects on a case-by-case basis. In Minnesota, water reuse requirements are included in NPDES permits administered by the Minnesota Pollution Control Agency. This model has served well for the permits issued to date, but there is limited information available for those seeking to explore water reuse, and questions have surfaced regarding the applicability of the California criteria for cold-winter climates and specific issues for the Midwest region. The modifications for reclaimed water production must continue to meet existing NPDES and other permit requirements and consider future permit conditions. Some treatment technologies result in concentrated waste streams, and there is concern that pollutant concentration discharge limits (i.e., TDS, chloride, sulfate, boron, and specific conductance) may exceed the water quality standards for some receiving streams. There are existing industries that cannot expand operations because they cannot cost effectively reduce salt concentrations in the discharge and meet their NPDES permit. Recent requirements for monitoring salty discharges at municipal WWTFs in Minnesota indicate that permit limits may be forthcoming for parameters that some WWTFs cannot currently achieve. The incorporation of reclaimed water practices may increase salt concentrations in the WWTF effluent and become a deterrent to water reuse at some facilities (MPCA 2011). Most reclaimed water uses will require higher quality water than is currently produced by a WWTP, as with cooling water. Many Midwest communities have hard and high salt waters, which lead to more concentrated salts in the wastewater, particularly for areas relying on home softening systems. Removal of hardness and high salt levels significantly adds to the cost.

environmental regulations and stewardship will increasingly drive the need to find alternative water supplies. Looking to balance income from water supply and the need to build more infrastructure, communities can partner with local industries and businesses to provide conditions where water reuse can provide environmental benefits and economic advantages for all partners.

5.2.5 South Central: Arkansas, Louisiana, New Mexico, Oklahoma, and Texas This section focuses on the regulatory context and drivers for water reuse in five states in the South Central region.

5.2.5.1 Population and Land Use Figure 5-22 compares the change in population in the South Central region to the United States over the past decade. The figure also compares the percent change in developed land between the region and the United States. 18.0 16.0

15.5

14.0

Percent Change

development of TMDL programs. For example, the Lake Pepin TMDL is projected to require a reduction of one-half the phosphorus and solids loads to Lake Pepin (Mississippi River segment), which will affect nearly two-thirds of Minnesota.

12.0 10.0

9.7 South Central Region

8.0 5.7

6.0

US

4.3

4.0 2.0 0.0 Population

Land Use

Figure 5-22 Change in population (2000-2010) and developed land (1997-2007) in the South Central region, compared to the United States

Compared to other regions, the South Central region is second only to the Mountain and Plains region in percent population growth. In the Southwest, the greatest population growth over the past decade has occurred in Texas (20.9 percent) and New Mexico (13.2 percent).

5.2.5.2 Precipitation and Climate Figure 5-23 depicts average monthly precipitation in the South Central region by state.

Reclaimed water is an emerging water supply for Minnesota communities and industries. Economic development, water supply limitations, and

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Chapter 5 | Regional Variations in Water Reuse

Average Rainfall (inches)

7.0 6.0

Public supply 14%

5.0 Arkansas

4.0

Louisiana

3.0

Oklahoma Texas

1.0

Dec

Oct

Nov

Sept

Jul

Aug

Jun

Apr

May

Mar

Jan

Feb

0.0

Month

Figure 5-23 Average monthly precipitation in the South Central region

The graphs above present long-term average precipitation. Drought conditions for the last three years in the region have depleted surface water reservoirs and reduced recharge to groundwater aquifers. According to the U.S. Drought Monitor, as of May 1, 2012, over 83 percent of Texas was still in severe (D-3) to exceptional (D-5) drought conditions (Rosencrans, 2012). Southeastern New Mexico shares the fate of West Texas with severe to exceptional drought over most of the state, with relieve to abnormally dry (D-0) conditions in the northwest corner of New Mexico. With reservoir and aquifer levels dropping, many communities are increasing their conversion to or use of reclaimed water. In West Texas, the Colorado River Municipal Water District is constructing a 2.3 mgd (101 L/s) IPR project that will convert Big Spring wastewater into higher than potable quality and blend the product water with raw water from one of three reservoirs that still has some water. The blended water is then treated at surface water treatment plants in six different communities [US-TX-Big Spring]. The community of Brownwood is in design/construction of a direct potable augmentation plant to supplement supply from a reservoir that may be depleted by the end of 2012 without significant rainfall.

5.2.5.3 Water Use by Sector Figure 5-24 shows freshwater use by sector in the South Central region.

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Thermoelectric 25%

New Mexico

2.0

Domestic selfsupply 1%

Mining 3% Industrial 8%

Irrigation 45%

Aquaculture 1% Livestock 3%

Figure 5-24 Freshwater use by sector for the South Central region

Irrigation is the largest water user in the region, and reclaimed water is commonly used for irrigation. However, the cost of incremental treatment and distribution for irrigation is a barrier to significant expansion in this sector. Thermoelectric power generation is another large potential use sector for expanding reuse.

5.2.5.4. States’ Regulatory Context

Arkansas and Louisiana At this time, Louisiana does not have regulations or guidelines specifically addressing water reuse. Arkansas had guidelines prior and now has adopted land disposal regulations with a provision for irrigation of forage and non-contact crops. New Mexico In 2007, New Mexico Environment Department (NMED) created an updated reclaimed water guidance document “NMED Ground Water Quality Bureau Guidance: Above Ground Use of Reclaimed Domestic Wastewater” that supersedes 1985 and 2003 policy statements. Current guidance identifies four different qualities of reclaimed water, with Class 1A being the highest quality for unrestricted urban uses. Class 1A is based on treatment processes that remove colloidal material and color that can interfere with disinfection. Classes 1B, 2, and 3 are based on secondary treatment processes. Spray irrigation of food crops is not allowed, although surface irrigation with Class 1B or 1A is allowed without contact with edible portions of crops.

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

Oklahoma Oklahoma has proposed and adopted new water reuse regulations in Chapter 627 Water Reuse and Chapter 656 Water Pollution Control Facility Construction Standards, which became effective July 1, 2012. The new rules create four categories of reclaimed water (Categories 2 through 5). Each category has a different level of treatment and permitted uses. Regulations for Category 2 for unrestricted access irrigation exclude application on food crops that could be eaten unprocessed and on processed food crops within 30 days of harvest. For Category 3 reclaimed water, the regulations also exclude use on athletic fields with potential for skin to ground contact. Current reuse applications in Oklahoma have been primarily small community irrigation systems. Uses have expanded into higher intensity agricultural irrigation, unrestricted golf course irrigation, livestock watering, dust control and soil compaction, concrete mixing, cooling towers and chilled water cooling, industrial process water, boiler feed, and land vehicle and equipment washing, excluding self-service car washes. Texas Reclaimed water use in Texas is regulated by TCEQ based on Chapter 210 Regulations in the state code. Chapter 210 was first created in 1997 with additions in 2002 to add sub-chapter E specifically addressing industrial process water reuse; in 2005 with sections added at 210, 281, and 285 to describe conditions for graywater use; and in 2009 to amend section 210.33 related to bacterial limitation revisions. Monitoring for Enterococci with a limit of 4 CFU/100 mL as a monthly geometric mean and no single sample greater than 9 CFU/100 mL was added for Type I Reclaimed Water (unrestricted use) with a limit of 35 CFU/100 mL added for Type II Reclaimed Water (restricted use). Many stakeholders participated in a three-year review of the 210 rules with changes proposed to TCEQ in 2003 (Vandertulip, et al., 2004). Some of the proposed revisions were incorporated into a revised WWTP design rule when Chapter 317 was revised to Chapter 217 by TCEQ, effective August 28, 2008. Reclaimed water use in Texas is by authorization from the TCEQ Executive Director upon application by a reclaimed water producer. The producer must have a permitted WWTP and provide reclaimed water of the

2012 Guidelines for Water Reuse

quality (Type I or II) required for the intended use and meet all Chapter 210 requirements. In 2007, the city of Midland petitioned TCEQ for new rulemaking relative to siting, permitting, and construction of satellite reclamation facilities. Chapter 321 P was created and effective November 28, 2008. Chapter 321 extends the executive director authorization process by allowing construction and operation of a satellite WRF upstream of an existing permitted WWTP. If special siting requirements are met, the facility can be constructed by authorization without additional hearings or permits. The buffer zone requirement doubles to 300 ft (91 m) from any treatment unit unless the reclamation facility is in a building with odor control, then the buffer zone drops to 50 ft (15 m). All screenings and waste biosolids must be returned to the wastewater collection system, and no increase in permitted treatment capacity is included (Vandertulip and Pype, 2009). For larger systems serving a population of more than 1 million, the state legislature passed House Bill 1922 in 2009, allowing larger systems to commingle reclaimed water supplies in a common distribution system and to discharge from the reclaimed water system at any permitted discharge point. This legislation was proposed based on supply reliability and balancing system capacity, specifically to address the transmission loop for SAWS. With three water reclamation facilities feeding into the reclaimed water distribution system and seven discharge points, portions of the system were isolated by valves as TCEQ determined that discharge from one plant could not supply a system with a discharge point permitted to another WRF. HB 1922 clarified that a looped system operated by one entity could operate with multiple feeds and multiple discharge points. If a permit violation were to exist and the offending WRC could not be identified, any permit violations would apply to the largest WRF in service (Schenk and Vandertulip, 2009).

5.2.5.5 Context and Drivers of Water Reuse In arid regions from Texas west through Arizona (including Oklahoma and New Mexico), reuse is becoming a vital component of water management. These communities have embraced the use of alternative sources of water to meet the growing need for the vital element. Drought conditions in the Southwest and many parts of Texas have driven municipalities to exploit the use of reclaimed water for

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Chapter 5 | Regional Variations in Water Reuse

nonpotable uses as well as for stream and aquifer augmentation. Texas El Paso Water Utility (EPWU) began pilot testing for IPR to augment the Hueco Bolson aquifer in 1978 with operation of an 8 mgd (351 L/s) facility beginning in 1985. They have expanded their portfolio of water reuse by conventional distribution of reclaimed water for irrigation, doubling the aquifer augmentation system and implementation of the largest inland brackish desalination project in the United States with 3 27.5 mgd (1.2 m /s) of supply added to the municipal water system. This integrated resource approach is being followed by the Colorado River Municipal Utility District (CRMUD) direct blending project in Big Spring, Texas [US-TX-Big Spring], where CRMUD is constructing a 2.3 mgd (101 L/s) water purification plant to treat Big Spring secondary filtered wastewater effluent through an MF/RO/advanced oxidation process (AOP) treatment process resulting in a product water with quality superior to potable quality. This product water will be blended in a raw water transmission main with water from Lake Spence and delivered as raw water to six existing surface water treatment plants operated by CRMUD member communities. Reclaimed water is marketed as having significant advantages, both for the consumer as well as for the supplier. The ability to have a reliable source of water during drought and at a lower rate than potable water provides the greatest advantages to the consumer. However, in the supplier’s standpoint, meeting contractual agreements whether based on quantity, redundancy, or even quality may become costly in the short or long term. Water Quality and Soil Conditions In some areas of the West, as is the case of El Paso, the source water has higher levels of salts than many water sources in other water rich communities. This creates a domino effect as it impacts the quality of reclaimed water, which has about twice the levels of salts than its source water. The reuse projects extend to areas within proximity of the treatment facilities. The soils in these areas are clay, caliche, or a combination of the two. Clay and caliche soils prevent the percolation or leaching of salts, creating a surface accumulation of salts, which hinders the proper development of plants. The areas where optimal soil

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conditions are found are limited and might be far from the treatment facility. Thus, application of reclaimed water must be carefully managed to prevent detrimental effects on soil quality and performance of the vegetative landscape due to unfavorable soil characteristics (Miyamoto, 2000, 2001, and 2003) [USTX-Landscape Study]. To offset impact of saline water supplies, EPWU has incorporated into its project planning a protocol to perform a soil suitability assessment to determine the preliminary condition of the soil that will be subjected to reclaimed water application and the vegetative landscape to set a benchmark condition of the plants and assess any potential to damages after exposure to reclaimed water (Miyamoto, 2004). This tool has been significantly important, as it ranks the suitability of all potential customer sites in order of suitable, suitable with some modification requirements, or non-suitable, prior to finalizing the project and selecting those customers that will be allowed to connect. Customers that are categorized as non-suitable or suitable with some modification are offered the opportunity to explore the level of retrofitting required for reuse. Customers who do not wish to invest in any amendment, are withdrawn from the project, thus minimizing, in most cases, the need to extend pipelines to areas where there are not a high number of customers and where it may not be financially feasible to recuperate the investment. In the El Paso scenario, mitigation of seasonal spikes in salinity of reclaimed water has been addressed in a more rudimentary fashion. Although concentration of salts in reclaimed water above the maximum limits required by a specific customer may not happen every year, the utility has learned that these fluctuations in TDS can be mitigated by the ability to blend with potable water at a localized point, thus preventing claims for plant damage. To dilute reclaimed water with elevated salinity, reservoirs are fitted with piping that can be manually operated to add potable water to the reservoir to blend with the reclaimed water. The cost to the customer is not modified when potable water is added to the system; it does, however, increase the operational costs to the utility. In addition to the ability to blend with potable water, the reservoirs have been equipped with recirculating and chlorine injection systems that allow for chemical addition and water mixing, thereby preventing

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

pathogen regrowth by maintaining a minimum chlorine residual level. Careful consideration of soil composition and existing plant material in selection of potential irrigation customers and impacts of aggressive conservation programs are all aspects of balancing water that have reshaped the planning and phasing of reuse programs in the United States. In-depth evaluation of soils subjected to irrigation with reclaimed water has been one of the most important considerations in planning a reuse program in El Paso. These studies have been instrumental in the effective use of reclaimed water and prevention of further soil degradation. Costs for biennial soil monitoring have also been budgeted by the utility, with no cost assessed to the customer. Customers do absorb the cost for any plant loss and soil amendments necessary. Conservation Impact on RW Quality Other conservation measures, such as use of low and ultra-low flow showerheads, toilets, sinks, washers, etc., continue to increase throughout the United States, so wastewater flows to the treatment facilities may be decreasing. Added to this is the increased use of in-situ graywater systems and increased tendencies for achieving sustainability for “green buildings” energy and conservation credits, where applicable. All combined, these factors may, in some instances, impact not only the quantity but also the quality of wastewater available for reclamation. A study performed by EPWU in 2007 reflected the fact that increased conservation measures contributed to a decline of flows into WWTPs (Figures 5-25 and 5-26). In a period from 1994 to 2006, the strength of the wastewater inflow increased in terms of BOD5 (Figure 5-27) and ammonia nitrogen (NH3-N) (Figure 5-28) at three of the WWTPs studied. Total suspended solids (TSS) concentration also increased at one of the WWTPs (Figure 5-29) (Ornelas and Rojas, 2007). Impacts from water conservation must also be considered during a reuse project planning phase, including reductions in flow where no population increases are expected to overcome decreases in flow. Similar impacts to reduced wastewater influent flows and higher strength wastewater influents have been found in San Antonio and San Diego.

2012 Guidelines for Water Reuse

Oklahoma Reclaimed water has been used in some portions of Oklahoma (Oklahoma University golf course, Norman, Okla.) since 1996. More recently, the city of Norman conducted public forums on Sustainable Water Resources in 2010 and included water reuse as one of the available options to conserve and extend the regional water resources (Clinton, 2010). On May 9, 2011, the Bureau of Reclamation (USBR) announced the selection of nine feasibility studies for funding under WaterSMART’s Title XVI Water Reclamation and Reuse Program in California, Oklahoma, and Texas. The Central Oklahoma Water Conservancy District will conduct a feasibility study in collaboration with surrounding entities to assess alternatives to augment the supply of Lake Thunderbird in Central Oklahoma through the treatment of effluent or surface water. The study will assess alternatives to help postpone or eliminate withdrawals from the local aquifer and alleviate pressure to secure inter-basin water transfers (WRA News, 2011). Title XVI of P.L. 102-575 provides authority for the USBR water reuse program. WaterSMART is a program of the U.S. Department of the Interior that focuses on improving water conservation and sustainability (USBR, 2012). New Mexico New Mexico also is beginning to use more reclaimed water to augment limited natural resources. Projects are in place in many communities (Las Cruces, Alamogordo, Hobbs, Gallup, Santa Fe, and Clovis), and larger projects are expanding in Albuquerque and the surrounding area. The Albuquerque Bernalillo County Water Utility Authority operates the Southeast Water Reclamation plant, which provides reclaimed water to several golf courses, city parks, and a power plant under a simplified regulatory framework. Irrigation of park green space replaces 12 percent of the city’s water demand (Stomp, 2004). Including reclaimed water to reduce aquifer withdrawals is critical to slowing aquifer decline and subsidence in Albuquerque.

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Chapter 5 | Regional Variations in Water Reuse

Figure 5-25 Water consumption in El Paso, Texas

Figure 5-27 Wastewater influent strength, BOD5

Figure 5-26 Wastewater flows in El Paso, Texas

Figure 5-28 Wastewater influent strength, NH3-N

Figure 5-29 Wastewater influent strength, TSS

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5.2.6.1 Population and Land Use Figure 5-30 compares the percent change in population and in developed land coverage in the Mountain and Plains Regions to the entire United States over the past decade. 18.0 16.0

16.1

Percent Change

14.0 12.0 10.0

9.7

Mountain and Plains Region

8.0 5.7

6.0

US

4.0

3.5 3.0 Colorado

2.5

Montana

2.0

North Dakota

1.5

South Dakota

1.0

Utah Wyoming

0.5

Dec

Oct

Nov

Sept

Jul

Aug

Jun

Apr

May

0.0 Mar

This section focuses on the regulatory context and drivers for water reuse in six states in the Mountain and Plains region.

Figure 5-31 depicts average monthly precipitation in the Mountain and Plains region by state.

Jan

5.2.6 Mountain and Plains: Colorado, Montana, South Dakota, North Dakota, Utah, and Wyoming

5.2.6.2 Precipitation

Feb

North of Albuquerque at the Tamaya Resort, Santa Ana Pueblo built a WRF in conjunction with a Native American Casino/Resort and began using reclaimed water to irrigate the Pueblo’s golf course in the late 1990s. The facility was further upgraded in 2007 (WaterWorld, n.d.).

While Montana, North Dakota, and South Dakota have seen less than 10 percent population growth over the past decade, other states in the region have had more rapid growth. Population growth in Wyoming (14.1 percent), Utah (23.8 percent), and Colorado (16.9 percent) bring the regional population growth above the national average. In fact, on a percentage basis, this region has seen the largest population growth in the nation over this period.

Average Rainfall (inches)

The state’s fastest-growing community, Rio Rancho (located to the northwest of Albuquerque) could not obtain adequate potable water without meeting some of its needs with reclaimed water. One design-build project constructed two 0.6 mgd (26.3 L/s) MBR reclamation plants (Mariposa WRF and Cabezon WRF) that provide high quality reclaimed water for landscape and golf course irrigation. The Cabezon WRF design provides for future addition of increased treatment for indirect potable applications under a direct injection aquifer recharge project (Ryan, 2006).

Month

Figure 5-31 Average monthly precipitation in the Mountain and Plains region

Rainfall in this region typically peaks during the summer growing months. Combined with low density development (on average), this weakens some demand for reclaimed water use. As noted previously for Colorado, due to water rights conflicts, rainfall capture is not allowed to supplement local water demands.

5.2.6.3 Water Use by Sector Figure 5-32 shows freshwater use by sector in the Mountain and Plains region.

1.7

2.0 0.0 Population

Land Use

Figure 5-30 Change in population (2000-2010) and developed land (1997-2007) in the Mountain and Plains region, compared to the United States

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Chapter 5 | Regional Variations in Water Reuse

Thermoelectric 15% Industrial 1%

Mining 2%

Public supply 8% Domestic selfsupply <1%

Aquaculture 2% Livestock 2%

Irrigation 70%

Figure 5-32 Freshwater use by sector for the Mountain and Plains region

Although irrigation is the largest water user in the region and reclaimed water is commonly used for irrigation, cost of incremental treatment and distribution to is an impediment to expansion of reclaimed water integration.

5.2.6.4. States’ Regulatory Context

Colorado The Colorado Water Quality Control commission administers four reclaimed water regulations in the Code of Colorado Regulations 1002-84 Reclaimed Water Control Regulations. The regulation identifies three qualities of reclaimed water: Classes 1, 2, and 3, with Class 3 being the highest quality. Class 3 requires secondary treatment filtration and disinfection for use in unrestricted urban applications. Colorado water rights limit the amount of reclaimed water that can be used, with quantities limited to water quantities imported from western Colorado to the east side of the Rocky Mountains [US-CO-Water Rights]. Montana Montana established graywater rules in 2007 and updated those rules in 2009 as one step in providing higher quality on-site treatment and reducing water demands. Over the last three years, Montana DEQ staffs have been developing new wastewater design and treatment regulations, including a guidance document on reclaimed water. As of the time of publication, the new rules and standards are currently under review and public hearings.

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South Dakota South Dakota has guidelines on the reuse of reclaimed water for irrigation of food and non-food crops (including restricted urban reuse). Environmental reuse (in this case, releasing treated wastewater back to a water body) and groundwater recharge are covered by rules governing surface water quality standards and wastewater discharge permits. North Dakota North Dakota has guidance on water reuse for a number of categories (urban, agriculture, industrial, environmental, and groundwater recharge). While other categories of reuse are not explicitly covered at this time, guidance would allow it on a case-by-case basis. Utah Utah Division of Water Quality rules appear in Chapter R317-1, Utah Administrative Code. The rules provide for on-site use of reclaimed water inside a treatment plant boundary for landscape irrigation, washdown, and chlorination system feed water. Chapter R317-311 provides for alternate disposal methods of land application and reuse of either Type I (potential human contact) or Type II (human contact unlikely). Type I reuse is allowed for residential irrigation, urban uses, food crop irrigation, pastures, and recreational impoundments where human contact is likely. As of 2005, 10 projects were reusing over 8,500 ac-ft (7.6 mgd or 333 L/s) of reclaimed water, primarily for agricultural, golf course, and landscape irrigation (The Utah Division of Water Resources, 2005). Wyoming Wyoming does not have specific regulations or guidelines for water reuse; however, surface water discharge (environmental reuse) and groundwater recharge are covered through the discharge permitting rules. Any other uses, such as restricted and unrestricted urban reuse, agriculture irrigation, and both food and non-food crops are addressed on a case-by-case basis using the construction permitting regulations.

5.2.6.5 Context and Drivers of Water Reuse

Colorado Prior to the inception of the Code of Colorado Regulations 1002-84 Reclaimed Water Control Regulations, several communities had been using reclaimed water for irrigation for many years.

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Currently, 28 facilities in Colorado treat and distribute reclaimed water for beneficial uses, including irrigation, animal exhibit cleaning at the Denver Zoo, and cooling water for the Xcel Energy Plant [US-CO-Denver, USCO-Denver Zoo, US-CO-Denver Energy, and US-COSand Creek]. Several communities depend on reclaimed water in order to meet their irrigation needs. There are now more than 400 approved sites for the use of reclaimed water in Colorado. With current demands for water and expanding drought conditions, the use of reclaimed water in Colorado is moving not only to include new facilities, but possibly new uses, as well. Montana One of the earliest water reuse projects in Montana was at Colstrip, Mont. (Vandertulip and Prieto, 2008), which was originally a company mining town providing coal for locomotives. The mine and town were later sold to a power company, and reclaimed water was used for cooling and other industrial applications. Industrial applications, being less seasonal, are still considered a viable opportunity for reclaimed water. South Dakota The primary reuse of reclaimed water in South Dakota is irrigation of non-food crops. North Dakota Tharaldson Ethanol recognized the opportunity to provide reclaimed water for a 120 million gallon ethanol facility in Casselton, N.D. A 1.4 mgd (61 L/s) advanced membrane facility was constructed to treat city of Fargo WWTF effluent and transport it 26 miles to the ethanol facility by Cass Rural Water District. Waste streams from the ethanol facility are conveyed back to the Fargo WWTF and treated as part of the discharge to the Red River. In addition, reclaimed water is used in Jamestown, Fargo, and Dickinson for hydraulic fracturing. Utah Agricultural reuse, primarily for disposal purposes, has been the primary use of reclaimed water in Utah. To date, there has not been significant demand for alternative water sources, such as reclaimed water, for other uses. One agricultural project for the Heber Valley Special Service District uses 1.4 mgd (61 L/s) in agricultural applications to comply with a zero discharge requirement to the Provo River. There are several golf course irrigation projects and planning for

2012 Guidelines for Water Reuse

future uses in areas where population growth will likely exceed zero discharge capacity (Utah Division of Water Resources, 2005). Wyoming Until recently, water reuse projects in Wyoming were few and relatively small. Cheyenne launched the first major water recycling program in Wyoming, winning the WRA Education Program of the Year Award in 2008. Water reuse is regulated through issuance of construction permits, and up to nine facilities have been identified as using nearly 1,000 ac-ft (0.9 mgd or 39 L/s) of reclaimed water per year (0.3 billion gallons per year), primarily for irrigation. Recently, the Red Desert treatment facility opened in Rawlins, Wyo., treating up to 0.9 mgd (39 L/s) of water from hydraulic fracturing operations for reuse in subsequent hydraulic fracturing operations. Marathon Oil’s Adams Ranch treatment facility in Sheridan, Wyo., is treating up to 1.5 mgd (66 L/s) of “produced water” through an innovative green sand, ion exchange softening, and RO process. This project, which returns water to the ranch for irrigation and stream flow augmentation, was recognized by the American Academy of Environmental Engineers with its 2012 Honor Award for Industrial Waste Practice.

5.2.7 Pacific Southwest: Arizona, California, Hawaii, Nevada, U.S. Pacific Insular Area Territories (Territory of Guam, Territory of American Samoa, and the Commonwealth of the Northern Mariana Islands), and 147 Federally Recognized Tribal Nations This section focuses on the regulatory context and drivers for water reuse in the Pacific Southwest region of the United States, which includes Arizona, California, Hawaii, Nevada, the U.S. Pacific Insular Area Territories, and 147 federally recognized tribal nations.

5.2.7.1 Population and Land Use Figure 5-33 compares the percent change in population for the Pacific Southwest states of Arizona, California, Hawaii, and Nevada to the entire United States over the past decade. The figure also compares the percent change in coverage of developed land in the region and the United States over the past decade.

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5.2.7.2 Precipitation and Climate

13.0

Figure 5-34 depicts average monthly precipitation in the states of the Pacific Southwest—Arizona, California, Hawaii, and Nevada.

9.7

8.0

7.0

The Pacific Southwest states have seen significant population growth over the past decade, particularly in Arizona (24.6 percent) and Nevada (35 percent). Looking back at two decades, Arizona and Nevada have experienced truly staggering growth, with 74.4 percent and 124.7 percent growth, respectively, since 1990. These two states experienced the greatest growth rates in the nation since 1990. California’s growth rate over the past decade was similar to the national average, at 10.0 percent, but has grown by 25.2 percent since 1990. With California being the most populous state in the nation, home to 37.3 million residents, the growth rate is nonetheless quite significant from a standpoint of natural resources, since the state added 3.4 million residents in 10 years. In terms of absolute numbers, this represents the largest population increase in the country during this period. Hawaii has exceeded the national average, with a growth rate of 12.3 percent. Hawaii has a resident population of 1.36 million people and annual visitor arrivals of 9.13 million. It is the only state not located on the North American continent and the only state located within the tropics. Lying 2,100 mi west and south of California, Hawaii shares the same general north latitude as Mexico City, Calcutta, Hong Kong, Mecca, and the Sahara Desert. Six major islands (Hawaii, Maui, Oahu, Kauai, Molokai and Lanai) and two smaller islands (Niihau and Kahoolawe) totaling 2 6,463 mi comprise an island chain stretching northwest to southeast over a zone 430 mi long.

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Dec

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Figure 5-33 Change in population (2000-2010) and developed land (1997-2007) in the Pacific Southwest region, compared to the United States

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Figure 5-34 Average monthly precipitation in the Pacific Southwest region

There is obvious variance in annual rainfall between Hawaii and the three contiguous states. Within California, the average condition shown in the graph is potentially misleading, with an annual average low rainfall of 1.6 in (4 cm) at Cow Creek in Death Valley and 104.18 in (264.6 cm) at Honeydew in northern California. With a statewide average of 22.2 in (56.3 cm), California ranks 40 in the list of wettest states (Coolweather, n.d.). Arizona averages 13.61 in (34.6 cm) per year with an annual range from 3.01 in (7.6 cm) in Yuma to 22.91 in (58.2 cm) in Flagstaff. Arizona is ranked the 47th wettest state (Coolweather, n.d.). Nevada is the driest state in the United States. Annual rainfall varies from 4.49 in (11.4 cm) per year in Las Vegas to 9.97 in (25.4 cm) in Ely (NOAA, n.d.). With the largest population and driest climate in the state, Las Vegas faces a significant challenge in meeting its water resource needs. Hawaii’s extreme geographical variations are manifest in extreme geographical rainfall variations. Although almost half the state is within 5 mi (8 km) of the seashore, 50 percent of the state is above 2,000 ft (609.6 m) in elevation and 10 percent is above 7,000 ft (2,133.6 m). Three mountain masses rise over 10,000 ft (3,048) above mean sea level, with Mauna Loa and Mauna Kea rising over 13,000 ft (3,962.4 m). It is not unusual for snow to cap the summits of Mauna Loa, Mauna Kea, and Haleakala when winter storm

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events are temperatures.

combined

with

below

freezing

Dominant trade winds blowing in a general east to west direction and the influence of the islands’ terrain provide special climatic character to the islands. Constant flow of fresh ocean air across the islands and small variation in solar energy are principal reasons for the slight seasonal temperature variations through much of Hawaii. Lowland daytime temperatures are commonly 70 to 80 degrees F (21.1 to 26.6 degrees C), and nighttime temperatures commonly range from 60 to 70 degrees F (15.5 to 21.1 degrees C). Hawaii’s steep rainfall gradients are reflected in the significant variations in precipitation throughout the islands and across individual islands. The lowest annual average precipitation is 5.7 in (14.5 cm) at Puako, Hawaii Island, and the highest average annual precipitation of 460.00 in (11.7 m) is at Mount Waialeale, Kauai. Overall, however, Hawaii’s actual average annual rainfall is about 70 in (178 cm). Figure 5-34 depicts average monthly precipitation in Hawaii.

5.2.7.3 Water Use by Sector Figure 5-35 shows freshwater use by sector in the Pacific Southwest region states of Arizona, California, Hawaii, and Nevada. The Pacific Southwest includes several of the driest states in the continental United States and Hawaii, with equally dry areas contrasted by areas with high rainfall. California has a long history of water reuse, while Hawaii’s experience is more recent.

Mining 2%

Thermoelectric 27%

Public supply 19%

Domestic selfsupply 1%

Industrial 1% Aquaculture 1% Livestock <1%

Irrigation 49%

Figure 5-35 Freshwater use by sector for the Pacific Southwest region

2012 Guidelines for Water Reuse

Irrigation use is common among the four states with California’s use for agricultural and landscape irrigation accounting for 54 percent of the reuse. Arizona has significant water reuse in the power 3 industry with over 80 mgd (3.5 m /s) devoted to supporting power generation at Palo Verde Nuclear Generation Station. One trend in each of the states is increased interest in IPR to support sustainable potable water supplies to meet growing populations.

5.2.7.4. States’ Regulatory Context

Arizona Reclaimed water regulations in Arizona have evolved since initial adoption in January 1972. The current regulations, adopted in January 2001, address reclaimed water permitting, requirements for reclaimed water conveyances, reclaimed water quality standards, and allowable end uses. These rules are codified in Arizona Administrative Code Title 18, Chapter 9, Articles 6 and 7 (Reclaimed Water Quality Conveyances and Direct Reuse of Reclaimed Water, respectively), and Title 18, Chapter 11, Article 3 (Reclaimed Water Quality Standards). Under the Chapter 11 provisions regarding reclaimed water quality standards, Arizona established five qualities of reclaimed water from A+ to C, with A+ being the highest quality. Class A+ reclaimed water in Arizona receives secondary treatment followed by filtration, disinfection, and nitrogen reduction to less than 10 mg/L total nitrogen. Table A in the regulation identifies the appropriate minimum quality for 27 categories of approved uses. Quality required for industrial reuse is industry specific and will be determined on a case-bycase basis by the ADEQ. In August 2009, the Governor formed a Blue Ribbon Panel on Water Sustainability consisting of 40 panelists representing a cross-section of state interest [US-AZ-Blue Ribbon Panel]. The purpose of the panel was “To advance statewide sustainability of water by increasing the reuse, recycling and conservation of water to support continued economic development in the state of Arizona while protecting Arizona’s water supplies and natural environment.” To accomplish this, the panel developed five goals and five working groups to address: 1) Increasing the volume of reclaimed water used for beneficial purposes in place of raw or potable water; 2) Advancing water conservation; 3) Reducing the amount of energy needed to produce, deliver, treat, reclaim, and reuse water; 4) Reducing the amount of water required to

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produce and provide energy by Arizona power generators; and 5) Increasing public awareness and acceptance of reclaimed water uses. The Panel’s 18 recommendations were released in a final report on November 30, 2010. The panel concluded that no new regulatory programs or major reconstruction of existing programs were needed and that current programs “constitute an exceptional framework within which water sustainability can be pursued.” The panel’s recommendations focused on improving existing capabilities in water management, education, and research. Significant research is being conducted in Arizona in support of the Blue Ribbon Panel recommendations, including chemical water quality; microbial water quality; optimization and life cycle analysis; and societal, legal, and institutional Issues. California Current regulations in California related to water reuse are complex and have been in a state of continual flux as water districts and utilities look to expand their use of reclaimed water. California statutes governing water use and the protection of water quality are contained in the California Water Code, which includes varying degrees of permitting authority by nine Regional Water Quality Control Boards (RWQCB), the SWRCB, and the CDPH. Each RWQCB is given authority to regulate specific reclaimed water discharges through the establishment of Water Quality Control Plans (Basin Plans), which include water quality objectives to protect beneficial uses of surface waters and groundwaters within the region. The SWRCB is authorized to adopt statewide policies for water quality control, which are then implemented by each RWQCB. The RWQCB issues the permits based on CDPH Title 22 requirements and comments on the specific project. Finally, CDPH is required to establish uniform statewide water reuse criteria for each type of reclaimed water, wherever the uses are related to public health. In 2009, the SWRCB adopted a Recycled Water Policy to provide uniformity in the interpretation and implementation of a 1968 anti-degradation policy by each RWQCB for water reuse projects. The policy includes specific requirements for salt/nutrient management plans, special provisions for groundwater recharge projects, anti-degradation, and monitoring for constituents of emerging concern.

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Salt/nutrient management plans are a critical component of the new Recycled Water Policy, as the accumulation of salts within soils and groundwater basins has been a long-term challenge in a state with little rainfall, high evaporation rates, and large agricultural and irrigation demands. The salt/nutrient management plans are being adopted by individual RWQCBs as amendments to their current basin plans and will include sources and loadings of salts, nutrients, and other pollutants of concern for each basin; implementation measures to manage pollutant loadings on a sustainable basis; and anti-degradation analysis demonstrating that all reclaimed water projects identified in the plan will collectively satisfy the state’s anti-degradation policy and applicable waterquality objectives in the basin plans. The special provisions for groundwater recharge projects in the Recycled Water Policy require sitespecific, project-by-project review and establish criteria for RWQCB approval, including a one year, expedited permit process for projects that use RO treatment for surface spreading. CDPH regulations are codified within the California Code of Regulations, with specific provisions related to reclaimed water within California Code of Regulations Title 22 and 17. Regulations governing nonpotable reuse include specific water quality, treatment, and monitoring requirements identified in California Code of Regulations Title 22 and enforced by the various RWQCBs. These regulations have remained relatively static over the last 10 years, with recent changes related primarily to laboratory and operator certification requirements. In addition, CDPH has developed a series of draft groundwater recharge regulations that are used as a basis for the case-by-case approval of individual groundwater replenishment projects. Current codified regulations in California Code of Regulations Title 22 include only narrative requirements for IPR, without specific provisions for treatment or water quality. Amendments to the California Water Code (CWC) made in 2010 require CDPH to adopt formal groundwater recharge regulations by December 31, 2013, while developing surface water augmentation regulations and a policy on direct potable reuse by December 31, 2016 (CWC 13350, 13521, and 13560 to 13569).

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The current draft of the groundwater recharge regulations was published in November 2011 and defines separate requirements for direct injection, surface spreading, and surface spreading without advanced treatment. Full advanced treatment, defined as RO followed by advanced oxidation, is required for direct injection or for surface spreading projects where strict TOC limits cannot be met and reclaimed water contribution to the groundwater exceeds 20 percent. The draft regulations include specific limits for TOC, total nitrogen, and other regulated and previously unregulated water quality parameters, as well as pathogen reduction requirements that include a 12-log reduction for enteric virus, 10-log for Giardia cyst, and 10-log for Cryptosporidium oocyst. Recharged water must be retained underground for a minimum of two months. The regulations also allow for alternative treatment approaches evaluated on a case-by-case basis and give credit for soil aquifer treatment when surface spreading is employed. Hawaii All water reuse projects in the state of Hawaii are subject to the review and approval by the Hawaii State Department of Health Wastewater Branch. The Hawaii State Department of Health issued the “Guidelines for the Treatment and Use of Reclaimed Water” in November 1993. The guidelines were adopted into Hawaii Administrative Rules Title 11, Chapter 62, Wastewater Systems updated in May 2002 and retitled, “Guidelines for the Treatment and Use of Recycled Water.” The guidelines define three classes of reclaimed water as R-1, R-2, and R-3 water: 1. R-1 Water is the highest quality reclaimed water. It is treated effluent that has undergone filtration and disinfection and can be utilized for spray irrigation without restrictions on use. 2. R-2 Water is disinfected secondary (biologically) treated effluent. Its uses are subjected to specific restrictions and controls. 3. R-3 Water is the lowest quality reclaimed water. It is undisinfected, secondary treated effluent whose uses are severely limited. Nevada In addition to regulations, Nevada has guidelines for reuse in the form of Water Technical Sheets: WTS-1A

2012 Guidelines for Water Reuse

(General Design Criteria for Reclaimed Water Irrigation Use) and WTS-1B (General Criteria for Preparing an Effluent Management Plan). These documents describe criteria to be included in the required engineering plan for irrigation reuse projects and information to be evaluated in preparing a management plan for reclaimed water use. U.S. Pacific Insular Area Territories (Territory of Guam, Territory of American Samoa, and CNMI), and 147 federally recognized tribal nations CNMI has regulations that allow the reuse of wastewater. The regulations include defined treatment standards for land application, including limited types of irrigation. Use of reclaimed water for food crops, parks, playgrounds, schoolyards, residential/ commercial garden landscaping, or fountains is specifically prohibited. The CNMI regulations require other safety measures for reuse, including contingency planning, reporting requirements, design requirements, and signage requirements in the Chamorro, Carolinian, and English languages. No information was located on regulations or guidelines promulgated by the territories of Guam and American Samoa or by federally recognized tribal nations.

5.2.7.5 Context and Drivers of Water Reuse

Arizona Water reuse has become critical to many communities in Arizona as a means of ensuring a stable alternative water supply. In Gilbert, reclaimed water is an important element of the town’s ability to demonstrate a 100-year assured water supply (a requirement of the Arizona Groundwater Management Act’s stringent water conservation requirements). Without water reuse, the town would be subject to a state imposed growth moratorium [US-AZ-Gilbert]. Further north in the town of Prescott Valley, a national precedent was set in 2006 when the town held an auction for its effluent, creating marketable rights for effluent as a commodity for the first time in Arizona and in the United States as a whole [US-AZ-Prescott Valley]. Significant reclaimed water is used in Arizona for energy production and building cooling needs. The Palo Verde Nuclear Generating Station operated by Arizona Public Service has been receiving reclaimed water from the 91st Avenue Water Reclamation Plant in Phoenix for 25 years. Recent use has been 67,000 ac-ft/yr (6.0 mgd or 263 L/s), and a new contract was signed in 2010 allocating 80,000 ac-ft (7.2 mgd or 314 L/s) of reclaimed water per year for cooling water 5-41

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demand [US-AZ-Phoenix]. Other significant programs in Arizona include the city of Tucson water reuse program; the Scottsdale Water Campus; the city of Peoria Butler Drive WRF; the Cave Creek Water Reclamation Plant; and the City of Surprise, with a 6.6 mgd (289 L/s) distribution of Class A+ reclaimed water for direct reuse (35 percent) and aquifer recharge. The city of Tucson’s reclaimed water use in 2010 is shown in Figure 5-36. The city’s program includes an established delivery system and model crossconnection control and site inspection program [USAZ-Tucson]. 52 Schools 8% Other 6%

39 Parks 17% Other Providers 13%

18 Golf Courses 56%

CY 2010 deliveries – 16,125 ac-ft

Figure 5-36 2010 Reclaimed water use in Tucson, Ariz.

A prominent addition to industrial water reclamation is represented by the expansion of the Frito-Lay production facility in Casa Grande with a 0.65 mgd (29 L/s) industrial Process Water Recovery Treatment Plant (PWRTP) that saves 100 million gallons of water per year. This facility and other environmental achievements are described in a case study [US-AZFrito-Lay]. The EOP is operated by the city of Sierra Vista, Arizona, in Cochise County in the southeastern corner of the state to polish 2.5 mgd (110 L/s) of current flow through constructed wetlands and to recharge the local aquifer in order to mitigate the adverse impacts of continued groundwater pumping in the San Pedro River system. This project is detailed in a case study [US-AZ-Sierra Vista]. Overall, the ADEQ estimates that 65 percent of the WWTPs in Arizona now distribute treated wastewater for reuse, including 10 of the 12 largest plants.

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California Due to low seasonal rainfall, large population centers, and strong agricultural demands, reclaimed water has been utilized within the state of California for almost a century to meet irrigation and other nonpotable water needs. Initiated in 1960 with spreading basin recharge at the Montebello Forebay, IPR has been employed to supplement over-stressed potable water supplies, both through surface water spreading and through direct injection into potable water aquifers [US-CA-Los Angeles County]. A 2009 Municipal Wastewater Recycling Survey released by the SWRCB identified 669,000 ac-ft/yr (600 mgd) of reclaimed water being used in California, with 37 percent of this used for agricultural irrigation, 24 percent for landscape and golf course irrigation, and 19 percent for groundwater recharge and injection into seawater intrusion barriers (SWRCB, 2011). Figure 5-37 identifies the uses of reclaimed water from the 2009 survey.

Groundwater Recharge 79,700 12% Other 15,800 2% Natural System Restoration, Wetlands, Wildlife Habitat 29,600 4% Recreational Impoundment 25,800 4% Seawater Intrusion Barrier 47,100 7% Commercial 6,400 1% Industrial 47,100 7%

2009 669,000 acre-feet

Agricultural Irrigation 244,500 37%

Landscape Irrigation 112,600 17%

Geothermal Energy Production 14,900 2% Golf Course Irrigation 43,600 7%

Figure 5-37 Uses of recycled water in Calif. (SWRCB 2011)

Agricultural reuse is the largest user of reclaimed water in California. In Monterey, reclaimed water has been used since 1998 on prime farmland to grow cool season vegetables as part of an effort to reduce groundwater extraction [US-CA-Monterey]. Long-term (10-year) studies of soil salinity have been implemented to understand how different soil types in the region respond to the salt content of reclaimed water. In San Diego, the North City Reclamation Plant uses an electrodialysis reversal (EDR) system to desalinate advanced treated reclaimed water to provide a new source of high quality irrigation water,

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thereby reducing demand on the freshwater supply [US-CA-North City]. The desalinated reclaimed water is used to irrigate golf courses, plant nurseries, parks, highway green belts, and residential areas. In the city of Temecula, north of San Diego, local avocado, citrus, and grape farmers currently use fully treated drinking water for irrigation. Faced with rising potable water costs, farmers may go out of business. Recognizing the un-sustainability of the current system, the Rancho California Water District recently conducted a feasibility study to replace part of the irrigation water with reclaimed water [US-CA-Temecula]. An example of reuse for ecological purposes comes from Lake Elsinore, a recreational lake [US-CAElsinore Valley]. Lake Elsinore was plagued for decades by low water levels and high concentrations of nutrients, causing algal blooms. To improve lake levels while addressing nutrient concentrations, 5 mgd (219 L/s) of reclaimed water is now sent to the lake. An example of two utility districts teaming together as a cost-effective solution to distribute reclaimed water comes from the San Ramon Valley Reclaimed Water Program [US-CA-San Ramon]. DSRSD and the East Bay Municipal Utility District (EBMUD) formed a joint powers authority to develop and manage the San Ramon Valley Reclaimed Water Program. Despite differences in size, structure, and culture, the two agencies have successfully joined to plan a system that serves both newly built and retrofitted neighborhoods with reclaimed water for landscape irrigation. While the majority of water reuse in the state remains nonpotable, indirect potable uses have been growing rapidly, forcing adaptation and development of recycled water regulations to address the changing demands. In the 1970s, RO began being utilized in Orange County to treat wastewater before injecting it into barrier wells, preventing seawater intrusion into the potable water supply aquifer [US-CA-Orange County]. San Diego has identified IPR through reservoir augmentation as the preferred strategy to reduce reliance on imported water [US-CA-San Diego]. The Water Purification Demonstration Project currently underway is evaluating the feasibility of using advanced treatment technology to produce water that can be sent to the city’s San Vicente Reservoir, to be later treated for distribution as potable water.

2012 Guidelines for Water Reuse

Today there are four large-scale facilities in southern California utilizing membrane filtration, RO, and varying levels of UV disinfection and advanced oxidation to produce high quality purified water for direct injection into potable water aquifers. The four facilities are the Orange County Groundwater Replenishment System [US-CA-Orange County], West Basin Municipal Water District Edward C. Little Water Recycling Facility [US-CA-West Basin], Los Angeles Bureau of Sanitation Terminal Island Water Reclamation Plant, and the Water Replenishment District of Southern California Leo J. Vander Lans Water Treatment Facility [US-CA-Vander Lans]. Other facilities are also utilizing infiltration basins for surface spreading to recharge previously over-drafted aquifers with advanced treated wastewater, including the Montebello Forebay [US-CA-Los Angeles County] and the Inland Empire Utility Agency [US-CA-Santa Ana River]. The Water Replenishment District of Southern California operates a program to artificially replenish groundwater basins by spreading and injecting replenishment water, which includes imported water and reclaimed water [US-CA-Vander Lans]. Some regional entities in water scarce parts of California are providing support and incentives for new water reuse projects. The Santa Ana River watershed encompasses parts of four large counties in Southern California. The Santa Ana Watershed Project Authority has a comprehensive, integrated planning process called “One Water One Watershed,” to increase reuse from 10 to 17 percent by 2030. Reclaimed water uses include municipal use, agricultural irrigation, groundwater recharge, habitat and environmental protection, industrial use, and lake stabilization. A 40-year salinity management program is a key aspect of the integrated planning. The Metropolitan Water District of Southern California is a regional water wholesaler serving approximately 19 million people across six counties [US-CA-Southern California MWD]. To meet long-term water demands, Metropolitan provides a regional financial incentive program to encourage development of reclaimed water and groundwater recovery projects that reduce demand on imported water supplies. To date, Metropolitan has provided incentives to 64 water reuse projects throughout Metropolitan’s service area, which are expected to produce an ultimate yield of about

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323,000 ac-ft (105 billion gallons) per year when fully implemented. Hawaii Each Hawaiian island has wet areas and dry areas with great surpluses in some areas and great deficiencies in others. Historically, there has been an overall abundance of water, but the challenge has been one of distribution rather than a general water shortage. The majority of Hawaii’s potable water sources are groundwater. A growing population is increasing stress on the sustainability of these limited groundwater resources. Almost 70 percent of Hawaii’s potable water is used to irrigate agricultural crops, golf courses, and residential and commercial landscaping. The state of Hawaii, the city and county of Honolulu (Oahu), the county of Maui (Maui, Lanai, and Molokai), the county of Kauai, and the county of Hawaii are increasing water conservation and water reuse efforts to manage and preserve potable water resources. The Hawaii State Department of Land and Natural Resources Commission on Water Resource Management in partnership with USACE have determined that a water conservation plan for the state of Hawaii should be established. Water reuse is anticipated to be a significant component of the plan’s policy and program development. Although all six major Hawaiian Islands have reclaimed water projects, the existence or nonexistence of reclaimed water programs varies by county. The county of Maui and city and county of Honolulu have committed significant resources to promote and develop their respective reclaimed water programs. The county of Kauai does not have a stated reclaimed water program. The county of Hawaii does not have a reclaimed water program. Please see the case study [US-HI-Reuse] for more detail on reuse applications in Hawaii and a timeline of implementation.

stormwater return to Lake Mead, which results in a continuous water reuse cycle, fed by new river inflows. With this knowledge, high levels of treatment are provided and high technology water quality monitoring is applied to meet potable water quality for utility customers. Individual on-site graywater reuse is not allowed in Nevada, as little treatment is provided in the graywater systems compared to the municipal treatment systems, and water rights accounting does not recognize graywater, even if used in place of potable water. CNMI One of the golf courses on Saipan—the main inhabited island of the CNMI—uses land application of reclaimed water on non-accessible areas of the grounds (not on the playing greens). Federally Recognized Tribal Nations In Region 9, several tribal nations practice water reuse, particularly at facilities with transient populations in arid areas. For example, in rural Capay Valley, Calif., the Yoche Dehe Wintun Nation’s Cache Creek Casino Resort has on-site water reclamation and reuse for golf course irrigation, toilet flushing, and decorative water features (S. Roberts Co., 2009). To manage salinity for irrigation, the system includes desalination. In Alpine, Calif. the Viejas Band of Kumeyaay Indians have incorporated water reuse for landscape irrigation on their reservation, which has 400 non-transient residents and an average of 5,000 transient residents who are visitors to the Viejas Casino, an Outlet Mall and Recreational Vehicle Park (Bassyouni et al., 2006).

5.2.8 Pacific Northwest: Alaska, Idaho, Oregon, and Washington This section focuses on the regulatory context and drivers for water reuse in four states in the Pacific Northwest region.

Nevada As the driest state whose largest population base is located in Las Vegas, Nevada is faced with a significant potable water supply challenge. Lake Mead serves as the primary water supply for the city, along with some groundwater resources. Within the Las Vegas area drainage, all reclaimed water and

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Figure 5-38 compares the percent change in population and developed land coverage in the Pacific Northwest compared to the entire United States over the past decade. 16.0

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Eastern Washington has roughly twice the land area and one-third the population of western Washington.

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Figure 5-39 Average monthly precipitation in the Pacific Northwest region

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Figure 5-38 Change in population (2000-2010) and developed land (1997-2007) in the Pacific Northwest region, compared to the United States

The Pacific Northwest region’s population grew at 14.2 percent over the past decade, with significant population increases in Alaska (13.3 percent), Idaho (21.1 percent), Oregon (12.0 percent), and Washington (14.1 percent). Alaska has a population of 0.7 million residents, adding about 80,000 residents over the past decade. Idaho is the 39th most populous state with 1.6 million residents and the 14th largest state by land area. Oregon has 3.8 million residents. Washington State is the 13th most populous state with 6.7 million residents. The Cascade Range runs north-south, bisecting the state.

5.2.8.2 Precipitation and Climate Figure 5-39 depicts average monthly precipitation in the Pacific Northwest region by state. Western Washington, from the Cascades westward, has a mostly marine west coast climate with mild temperatures and wet winters, autumns, and springs, and relatively dry summers. Eastern Washington, east of the Cascades, has a relatively dry climate. Summers are warmer, winters are colder and precipitation is less than half of western Washington.

2012 Guidelines for Water Reuse

The climate in Oregon varies greatly between the western and eastern regions of the state. The Columbia and Snake rivers delineate much of Oregon’s northern and eastern boundaries, respectively. The landscape in Oregon is diverse and varies from rain forest in the Coast Range in the western region to barren desert in the southeast. An oceanic climate predominates in Western Oregon, and a much drier semi-arid climate prevails east of the Cascade Range in Eastern Oregon. Population centers lie mostly in the western part of the state, which is generally moist and mild, while the lightly populated high deserts of Central and Eastern Oregon are much drier. The four seasons are distinct in all parts of Idaho, but different parts of the state experience them differently. Spring comes earlier and winter later to Boise and Lewiston, which are protected from severe weather by nearby mountains and call themselves “banana belts.” Eastern Idaho has a more continental climate, with more extreme temperatures; climatic conditions there and elsewhere vary with the elevation. Humidity is low throughout the state. Precipitation in southern Idaho averages 13 in (33 cm) per year; in the north, precipitation averages over 30 in (76 cm) per year. Average annual precipitation (1971 to 2000) at Boise was 12.2 in (31 cm), with more than 21 in (53 cm) of snow. Much greater accumulations of snow are experienced in the mountains. Though possibly perceived as a state with high precipitation, Alaska actually ranks as the 39th wettest

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Chapter 5 | Regional Variations in Water Reuse

state (22.70 in or 57.7 cm annually) with an annual rainfall range from 4.16 in (10.6 cm) in Barrow on the north coast to 75.35 in (191 cm) in Kodiak in the south. Due to a colder climate, snowfall ranges from 30.3 in (77 cm) per year in Barrow to 322.9 in (8.2 m) in Valdez. The colder weather conditions limit agricultural applications, one of the historically high uses for reclaimed water.

5.2.8.3 Water Use by Sector Figure 5-40 shows freshwater use by sector in the Pacific Northwest.

Public supply 10%

Domestic selfsupply 1%

Thermoelectric 30% Irrigation 38%

Mining 3% Industrial 3%

Aquaculture 15% Livestock <1%

Figure 5-40 Freshwater use by sector for the Pacific Northwest region

Idaho, Oregon, and Washington have well developed regulations and standards. Idaho’s continuing efforts to support reuse, considering the different types of land application and treatment systems and end uses, have led to updates in state regulations and guidance over the years. With emphasis on in-stream water quality, focused on nutrients and sediment, all of the sectors in Idaho, Oregon, and Washington could anticipate increased interest in water reuse.

5.2.8.4. States’ Regulatory Context

Alaska Alaska does not have regulations that specifically address water reuse. Idaho Idaho has both reuse regulations and guidelines whose scope includes treatment and beneficial reuse of municipal and industrial wastewater. Water reuse by different types of land application facilities is allowed

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by state regulations. In 1988, Idaho’s Wastewater Land Application permitting rules were promulgated and guidance was developed. Idaho has a public advisory working group that meets periodically to advise guidance development and review existing and future reuse guidance. In 2011 reuse regulations were updated, and the name of the rules changed to Recycled Water Rules (IDAPA 58.01.17). Idaho DEQ is the state agency tasked with issuing both industrial and municipal reuse permits. In Idaho, the NPDES permit program, which includes discharge of reclaimed water to surface waters, is administered by EPA, which means EPA is responsible for issuing and enforcing all NPDES permits in Idaho. Oregon The Oregon Administrative Rules, Chapter 340, Division 55 (OAR 340-055), “Recycled Water Use,” prescribe the requirements for the use of reclaimed water for beneficial purposes while protecting public health and the environment. The Oregon DEQ is responsible for implementing these rules. The department coordinates closely with other state agencies to ensure consistency; in particular, the Oregon Department of Human Services and the Oregon Water Resources Department also play key roles in implementing these rules. Facilities are required to manage and operate reclaimed water projects under a water reuse management plan. These plans are specific to each facility and are considered part of a facility’s NPDES or water pollution control facility (WPCF) water quality permit. Site-specific conditions, such as application rates and setbacks, may be established to ensure the protection of public health and the environment. Washington In 1992 the Washington State Legislature passed the Reclaimed Water Act, Chapter 90.46 RCW. The Reclaimed Water Act and Chapters 90.48 and 90.82 RCW encourage the development and use of reclaimed water, require consideration of reclaimed water in wastewater and water supply planning, and recognize the importance of reclaimed water as a strategy within water resource management statewide. Reclaimed water is recognized as a resource that can be integrated into state, regional, and local strategies to respond to population growth and climate change. The state also recognizes reclaimed water as an important mechanism for reducing discharge of treated wastewater into Puget Sound and other sensitive

2012 Guidelines for Water Reuse

Chapter 5 | Regional Variations in Water Reuse

areas for improving water quality in the Sound. For more history on the regulatory context in Washington state, refer to the case study [US-WA-Regulations].

5.2.8.5 Context and Drivers of Water Reuse

Alaska Water reuse in Alaska is not regularly implemented. Idaho Idaho has been supporting reuse since 1988, and 2011 Idaho DEQ data indicate that 8.5 billion gallons of wastewater were reused by municipal and industrial sites. The drivers for the use of reclaimed water include more stringent discharge regulations, water supply demands, the need to offset potable water use, and a need to reduce pollutant loads and discharge volumes in receiving waters. There are 136 reuse permits in the state, and the number of permits is expected to grow due to strict TMDL limits for pollutants such as phosphorus. The first municipal land application/reuse permit was issued to the city of Rupert in 1989, and the first industrial reuse permit was issued in 1990 to Lamb Weston, a potato processor. Although municipal reuse has been permitted for many years, the city of Meridian is the first municipal system in the state with a city-wide Class A permit. Several years ago the city had a desire to explore the use of reclaimed water at the city park, located one and a-half miles north of the WWTP. The city was able to convert a seldom used outfall line to transport reclaimed water from the plant to the park for irrigation. Additionally, this outfall line provided the chlorine contact time required to meet the city’s site-specific permit. The elevated chlorine levels at the park and nutrients in the reclaimed water presented challenges with the clarity of the holding pond that the city discharged into prior to irrigation. This and other factors led to the city moving to a pressurized reclaimed water system that is currently going through startup testing. This system, coupled with a citywide reuse permit, will allow the city to use reclaimed water at a new interchange, the city park, the WWTP, and a car wash. Since 2004 the Idaho DEQ has hosted an annual water reuse conference designed to enable water and wastewater professionals to continue their education, network, and discuss key issues related to water reuse in Idaho and the West.

2012 Guidelines for Water Reuse

Oregon Water reuse has been practiced in Oregon for several decades. There are more than two dozen facilities that implement water reuse programs throughout the state. Many people may think of water reuse in terms of crop or pasture irrigation. While this is a valuable use, there are many other uses practiced in Oregon, including irrigation of golf courses, playing fields, poplar tree plantations, and commercial landscapes; cooling in the production of electricity; and for wetland habitats. The drivers for water reuse in Oregon include limitations imposed by new surface water discharge regulations, impaired water bodies with TMDLs, opportunities due to upgrades with advanced treatment technologies, and water supply needs. The following are a few examples of how reclaimed water is used in Oregon: 

City of Prineville—golf course and pasture. Several years ago, the city of Prineville needed to look at non-discharge alternatives to the Crooked River during the summer months. An EPA construction grant assisted the city in developing a golf course irrigation system in which reclaimed water is used. The city owns and operates the golf course, thus generating revenue through playing fees. The city recently expanded the use of reclaimed water to irrigate nearby pasture land.



Clean Water Services (Washington County)— golf courses, playing fields, plant nursery. This public utility serving nearly 500,000 customers operates four major WWTFs and works with 12 member cities to provide reclaimed water for a variety of uses. Reclaimed water is used for irrigation of three golf courses, two school playing fields, and a plant nursery.



Metropolitan Wastewater Management Commission—poplar tree plantation. Serving the cities of Eugene and Springfield, this regional WWTF provides reclaimed water to its Biocycle Farm for a 596-ac poplar tree plantation. The irrigation system is designed to minimize overspray, wind drift, surface runoff, and ponding. Fences, buffers, and signage restrict unauthorized access to the site.



Albany Talking Water Gardens Projects— wetlands. A 37-ac integrated wetland treatment

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Chapter 5 | Regional Variations in Water Reuse

system enhances wildlife habitat while reducing the temperature, TDS, and nutrients in reclaimed water (CH2MHill, 2011). In addition, 13 ac of perimeter landscaping provides the opportunity to reuse effluent for irrigation to support more diverse habitat. The system is first in the nation designed to treat a unique combination of municipal and industrial WWTP effluents. 

City of Silverton Oregon Garden Project— wetlands. Similar to the system in Albany, the city of Silverton’s reclaimed water is used to create a thriving habitat through 17 acres of terraced ponds with cascading water, pools, and wetlands plants to a holding tank where it then flows into an irrigation system used to irrigate a garden (Oregon Garden, n.d.). The system lowers the temperature and removes nitrate and phosphorous prior to discharge in Brush Creek. The wetlands also play an active role in the education programs at The Garden.

Washington There are more than 25 reclaimed water facilities operating in Washington State—about one-third are located in eastern Washington and two-thirds are located in western Washington. The design capacity for these facilities range from less than 1 mgd (43.8 L/s) to 21 mgd (920 L/s). Approximately 35 reclaimed water facilities are in the planning or design phase. The drivers for reclaimed water facilities in Washington vary by facility and include discharge regulations, impaired water bodies with TMDLs, efforts to restore Puget Sound, opportunities due to upgrades or new facilities with advanced treatment technologies, and water supply needs. Water reuse in Washington includes golf course irrigation; urban uses, such as street sweeping; agricultural irrigation; forest irrigation; groundwater recharge; ASR; wetlands enhancement; stream-flow augmentation; and commercial and industrial processes. King County and the University of Washington collaborated in a study to demonstrate the safety of using Class A reclaimed water in a vegetable garden, as detailed in a case study [US-WA-King County]. In Sequim, a reclaimed water distribution system uses reclaimed water for toilet flushing, irrigation, stream augmentation, vehicle washing, street cleaning, fire truck water, and dust control [US-

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WA-Sequim], relying on a marine outfall to discharge wastewater when the reclamation process fails and seasonally when reclaimed water demand drops. In Yelm, reclaimed water is used in a wetlands park to have a highly visible and attractive focal point promoting reclaimed water use [US-WA-Yelm]. In addition, as part of planning for expansion of the reclaimed water system, a local ordinance was adopted establishing the conditions of reclaimed water use, which includes a “mandatory use” clause requiring construction of reclaimed water distribution facilities as a condition of development approval.

5.3 References

Bassyouni, A., M. Sudame, and D. McDermott. 2006. “Model Water Recycling Program.” WEFTEC Conference 2006. Water Environment Federation. Bennett, L. 2010. “Wastewater Reclamation and Reuse Projects in the State of Virginia, What’s Happening Around the State, VWEA/VA.” AWWA Water Reuse Committee Seminar, June 8, 2010. City of Raleigh. 2012. Reuse Water System. Retrieved on August 23, 2012 from . CH2MHill. 2011. Talking Water Gardens Natural Water Treatment and Reuse Project: Innovative Approach to Complex Water Quality Issues. Retrieved on August 23, 2012 from . Clinton, T. A. 2010. “Reclaimed Water.” City of Norman Public Forum Series On Sustainable Water Resources, February 4, 2010. Crook, J. 2005. “St. Petersburg, Florida, Dual Water System: A Case Study,” In Water Conservation, Reuse, and Recycling: Proceedings of an Iranian-American Workshop, National Academy Press. Retrieved on August 23, 2012 from . Coolweather. n.d. State Rainfall. Retrieved on August 23, 2012 from . Elfland, C. 2010. “UNC Chapel Hill’s Sustainable Water Infrastructure: A Ten Year Journey.” AWWA Sustainable Water Management Conference, April 12, 2010. Federal Register 77 (FR 77 2012):13496-13499, “Effective Date for the Water Quality Standards for the State of

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Chapter 5 | Regional Variations in Water Reuse

Florida’s Lakes and Flowing Waters.” 2012. Florida Department of Environmental Protection (FDEP). 2011. 2010 Reuse Inventory. Florida Department of Environmental Protection. Tallahassee, FL. Florida Department of Environmental Protection (FDEP). 2009. Connecting Reuse and Water Use: A Report of the Reuse Stakeholders Meetings. Florida Department of Environmental Protection. Tallahassee, FL. Retrieved on August 23, 2012 from . Florida Department of Environmental Protection (FDEP). 2012a. 2011 Reuse Inventory. Tallahassee, Florida. Retrieved on August 23, 2012 from . Florida Department of Environmental Protection. 2012b. Development of Numeric Nutrient Criteria for Florida’s Waters. Retrieved on August 23, 2012 from . Georgia Environmental Protection Division (GEPD). 2007. Reuse Feasibility Analysis, EPD Guidance Document. Atlanta, GA. Georgia Governor’s Office. 2009. Water Contingency Planning Task Force, Findings and Recommendations. Governor’s Task Force. Atlanta, GA. Global Water Intelligence (GWI). 2010. Municipal Water Reuse Markets 2010. Media Analytics Ltd. Oxford, UK. Goldenberg, B., C. Helfrich, A. Perez, A. Garcia, R. Chalmers, and P. Gleason. 2009. “The Impact of Legislation Eliminating the Use of Ocean Outfalls on Reuse in Southeast Florida.” WateReuse Symposium, Seattle, WA, October 2009. Kenny, J. F., N. L. Barber, S. S. Hutson, K. S. Linsey, J. K. Lovelace, and M. A. Maupin. 2009. “Estimated Use of Water in the United States in 2005.” United States Geological Survey (USGS). Retrieved on August 23, 2012 from . Metropolitan Area Planning Council (MAPC). 2005. “Once is Not Enough: A Guide to Water Reuse in Massachusetts.” Retrieved on August 23, 2012 from .

2012 Guidelines for Water Reuse

Metropolitan Council Environmental Services (MCES). 2007. Recycling Treated Municipal Wastewater for Industrial Water Use. A report prepared for the Legislative Commission on Minnesota Resources, August 2007. Metropolitan Council Environmental Services. St. Paul, MN. Retrieved August 23, 2012 from . Miles, W., R. Bonné, and A. Russell. 2003. “Startup and Operation of Cary, North Carolina’s Residential/Commercial Reclaimed Water System.” Virginia Water Environment Association. Glen Allen, VA. Miller, W. G. 2011. “Water Reuse in the U.S.A.: Current Challenges and New Initiatives.” 8th IWA International Conference on Water Reclamation and Reuse, Barcelona, Spain. Miller, W. G. 2012. Personal communication by document editors on extent of water reuse in the United States. Minnesota Department of Natural Resources (MDNR). 2008. Minnesota Water Appropriations Permit Program, State Water Use Data System. Data summarized through 2007 were obtained from the MDNR. Retrieved on August 23, 2012 from . Minnesota Pollution Control Agency (MPCA). 2011. “Salty Discharge” Monitoring at NPDES/SDS Permitted Facilities. Retrieved on August 23, 2012 from . Minnesota Pollution Control Agency (MPCA). 2010a. Biofuels: Reusing Municipal Wastewater. Retrieved on August 23, 2012 from . Minnesota Pollution Control Agency (MPCA). 2010b. Municipal Wastewater Reuse. Retrieved on August 23, 2012 from . Miyamoto, S. 2004. Landscape Plant Lists for Salt Tolerance Assessment. Texas A&M University Agricultural Research and Extension Center. El Paso, TX. Miyamoto, S. 2003. “Managing Salt Problems in Landscape Use of Reclaimed Water in the Southwest.” Watereuse Symposium. Alexandria, VA.

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Miyamoto, S. 2001. El Paso Guidelines for Landscape Uses of Reclaimed Water with Elevated Salinity. Texas A&M University Agricultural Research and Extension Center. El Paso, TX. Miyamoto, S. 2000. Soil Resources of El Paso: Characteristics, Distribution and Management Guidelines. Texas A&M University Agricultural Research and Extension Center. El Paso, TX. National Oceanic and Atmospheric Administration (NOAA). n.d. National Climatic Data Center. Thirty-year annual precipitation data. Retrieved on August 23, 2012 from . National Research Council (NRC) 2012. Water Reuse: Potential for Expanding the Nation’s Water Supply Through Reuse of Municipal Wastewater. National Academy Press. Washington, D. C. North Carolina Administrative Code (NCAC). 2011. North Carolina Reclaimed Water Regulations. 15A NCAC 02U. Retrieved on August 23, 2012 from . Oregon Garden. n.d. “Wetlands” Retrieved on August 23, 2012 from . Ornelas, D. and I. S. Rojas. 2007. “Managing Reclaimed Water Concerns Attributed to Declining Water Usage.” 11th Annual WateReuse Research Conference. WateReuse Association: Alexandria, VA. Rosencrans, M. 2012. U.S. Drought Monitor. Retrieved on August 31, 2012 from . Ryan, M. D. 2006. “Design-Build of Rio Rancho’s MBR Plants-A Win-Win-Win Success.” Design-Build Institute of America, January 26, 2006. Albuquerque, NM, S. Roberts Co. 2009. Cache Creek Desalination Facility. Retrieved on August 23, 2012 from .

Smith, D. A. and J. D. Wert. 2007. “University Area Joint Authority Beneficial Reuse Project-20 Months of Operation.” WEFTEC 2007. San Diego, CA. State Water Resources Control Board (SWRCB). 2011. Water Recycling Funding Program: Municipal Wastewater Recycling Survey. Retrieved on August 23, 2012 from . Stomp, J. 2004. Water Desalination And Reuse Strategies For New Mexico. New Mexico Water Resources Institute, Las Cruces, NM. Tennessee Tech University (TTU). 2012. Water Reuse Survey. Retrieved on August 23, 2012 from . Texas Commission on Environmental Quality (TCEQ). n.d. General Permits for Waste Discharges. Retrieved on August 23, 2012 from . Tien, C. 2010. “Maryland Water Reuse Regulations.” 19th Maryland Ground Water Symposium, September 29, 2010. Town of Cary. n.d. Reclaimed Water System. Retrieved on December 27, 2012 from . United States Census Bureau (USCB). n.d. Resident Population Data: 2000 and 2010. Retrieved on August 23, 2012 from . U.S. Department of Agriculture (USDA). 2009. Summary Report: 2007 National Resources Inventory. Natural Resources Conservation Service and Center for Survey Statistics and Methodology, Iowa State University. Retrieved on August 31, 2012 from . U.S. Department of the Interior, Bureau of Reclamation (USBR). 2012. WaterSMART (Sustain and Manage America’s Resources for Tomorrow). Retrieved on August 23, 2012 from .

Schenk, R. E. and D. Vandertulip. 2009. “The Next Step in Improving Texas Reclaimed Water Projects – Proposed Update of Chapter 210.” Texas Water, April 11, 2009. Galveston, TX.

U.S. Environmental Protection Agency (EPA). 2004. Guidelines for Water Reuse. 625/R-04/108. Environmental Protection Agency. Washington, D.C.

Shakopee Mdewakanton Sioux Community (SMSC), n.d. Shakopee Mdewakanton Sioux Community Department of Land and Natural Resources. Retrieved on August 31, 2012 from .

U.S. Environmental Protection Agency (EPA). 2007. National Nutrient Strategy. Retrieved on August 23, 2012 .

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U.S. Environmental Protection Agency (EPA). n.d. Federal Water Quality Standards for the State of Florida. Retrieved on August 23, 2012 from . The Utah Division of Water Resources. 2005. Water Reuse In Utah. Retrieved on August 23, 2012 from . Vandertulip, D. and L. Pype. 2009. “Water Reuse Practices – Current Uses and Future Trends.” Pennsylvania Water Environment Association PENNTEC 2009, June 9, 2009. Vandertulip, D. and L. Prieto. 2008. “Irrigation to Industrial: A Whole New World of Reuse Opportunities.” Montana Section AWWA/WEA Annual Conference, May 15, 2008. Great Falls, MT. Vandertulip, D., R. E. Schenk, and A. Plummer. 2004. “Texas 2003 Reuse Rule Revisions.” AWWA/WEF Water Sources Conference, January 2004. WaterWorld. n.d. Water Reuse: Experiences from the Santa Ana Pueblo. Retrieved on August 23, 2012 from

2012 Guidelines for Water Reuse

. Westmiller, R. 2010. “Purple, the New Gold.” Irrigation and Green Industry. October 2010(10):26-32. Whitcomb, J. B. 2005. Florida Water Rates Evaluation of Single-Family Homes. Prepared for Southwest Florida Water Management District, St. Johns River Water Management District, South Florida Water Management District, and Northwest Florida Water Management District. Retrieved on August 23, 2012 from . WRA News. 2011. Bureau of Reclamation Awards $1.2 Million for Water Reuse Studies in Three States. Retrieved on August 23, 2012 from . Wu, M., M. Mintz, M. Wang, and S. Arora. 2009. Consumptive Water Use in the Production of Ethanol and Petroleum Gasoline. Center for Transportation Research, Energy Systems Division, Argonne National Laboratory.

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2012 Guidelines for Water Reuse

CHAPTER 6 Treatment Technologies for Protecting Public and Environmental Health When discussing treatment for reuse, the key objective is to achieve a quality of reclaimed water that is appropriate for the intended use and is protective of human health and the environment. Secondary objectives for reclaimed water treatment are directly tied to the end application, and can include aesthetic goals (e.g., additional treatment for color or odor reduction) or specific user requirements (e.g., salt reduction for irrigation or industrial reuse). As described in Section 1.5 “Fit for Purpose,” treatment for reclaimed water is and should be tailored to a specific purpose so that treatment objectives can be appropriately set for public health and environmental protection, while being cost effective. Additionally, the appropriate treatment for reuse will vary depending upon state-specific requirements. Some states require specific treatment processes, others impose reclaimed water quality criteria, and some require both. Many states also include requirements for treatment reliability and resilience to process upsets, power outages, or equipment failure (see Chapter 4 for additional regulatory discussion). There have been hundreds of reuse projects implemented in the United States for various end uses and these projects, cumulatively, have demonstrated that use of properly treated reclaimed water meeting cross connection controls and use area requirements is protective of human health and the environment. While specifically proving the negative is difficult, i.e.,

that there have not been human health or environmental impacts associated with use of reclaimed water, at least one report notes that, “There have not been any confirmed cases of infectious disease that have been documented in the U.S. as having been caused by contact, ingestion, or inhalation of pathogenic microorganisms at any landscape irrigation site subject to reclaimed water criteria” (WRRF, 2005). Further, with respect to chemical hazards and risks, the NRC reports that, “To date, epidemiological analyses of adverse health effects likely to be associated with use of reclaimed water have not identified any patterns from water reuse projects in the United States” (NRC, 2012). There is a continuum of possible scenarios for nonpotable and potable reuse, ranging from distributed nonpotable reclaimed water, to long-term storage in an environmental buffer prior to reuse, to direct replenishment of potable water sources (prior to additional drinking water treatment). As an example, Figure 6-1 depicts a variety of treatment scenarios that have been developed for indirect or direct potable end use applications. There are other treatment technologies, not reflected in Figure 6-1, such as conventional secondary followed by natural treatment systems (wetlands or soil aquifer treatment prior to augmentation of drinking water supplies, which is described further in Section 6.4.5).

California Model IPR

WWTP

MF

RO

UV-A

Buffer

WTP

Surface Water (nutrients)

WWTP

MF

RO

IX

UV-A

Buffer Blend

WTP

Namibia Model (No RO)

WWTP

DAF

Media Filtration

Ozone

BAC/GAC

UF

Buffer Blend

Gwinnett County IPR

WWTP

MF

GAC

Ozone

Buffer Blend

WTP

MBR

RO

UV-A

Buffer Blend

WTP

Cloudcraft Model (MBR)

WTP

Figure 6-1 Potable reuse treatment scenarios (Chalmers et al., 2011) 2012 Guidelines for Water Reuse

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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

The important lesson is that now, regardless of the end use and desired reclaimed water quality there are technologies available to treat water to whatever level is required for the targeted end use. In addition to successful implementation of current advanced treatment technologies for producing reclaimed water, there is ongoing research into optimizing these processes and investigating emerging technologies to meet treatment objectives for both pathogens and chemical constituents (WRRF, 2007a; 2012a).

6.1 Public Health Considerations The most critical objective in any reuse program is to protect public health and a portfolio of treatment options exists to mitigate microbial and chemical contaminants in reclaimed water and meet specific water quality goals (NRC, 2012). Other objectives, such as preventing environmental degradation, avoiding public nuisance, and meeting user requirements, must also be satisfied, but the starting point remains the safe delivery and use of properly treated reclaimed water. In order to put concerns about protecting public health and the environment into perspective with respect to water reclamation, it is important to consider several key questions.

6.1.1 What is the Intended Use of the Reclaimed Water? Protection of public health is achieved by 1) reducing or eliminating concentrations of pathogenic bacteria, parasites, and enteric viruses in reclaimed water; 2) controlling chemical constituents in reclaimed water; and 3) limiting public exposure (contact, inhalation, or ingestion) to reclaimed water. Reclaimed water projects may vary significantly in the level of human exposure incurred, with a corresponding variation in the potential for health risks. Where human exposure is likely, reclaimed water should be treated to a high degree prior to its use (Table 6-1). Reclaimed water used for irrigation of non-food crops on a restricted agricultural site may be of lesser quality than water for landscape irrigation at a public park or school, which may be of a lesser quality than reclaimed water intended to augment potable supplies. To make reuse cost-effective, the level of treatment must be “fit for purpose.” Secondary effluent can become reclaimed water nonpotable reuse by addition of filtration and enhanced disinfection. Higher level uses (e.g., potable reuse) may include additional processes, such as membranes, advanced oxidation, or soil aquifer treatment to remove chemical and biological constituents.

Table 6-1 Types of reuse appropriate for increasing levels of treatment Increasing Levels of Treatment Treatment Level Processes

End Use

Primary Sedimentation

No Uses Recommended

Filtration and Disinfection

Secondary Biological oxidation and disinfection

Chemical coagulation, biological or chemical nutrient removal, filtration, and disinfection

Surface irrigation of orchards and vineyards

Landscape and golf course irrigation

Non-food crop irrigation

Toilet flushing

Restricted landscape impoundments

Vehicle washing

Groundwater recharge of nonpotable aquifer

Food crop irrigation

Wetlands, wildlife habitat, stream augmentation

Unrestricted recreational impoundment

Industrial cooling processes

Industrial systems

Human Exposure

Increasing Acceptable Levels of Human Exposure

Cost

Increasing Levels of Cost

6-2

Advanced Activated carbon, reverse osmosis, advanced oxidation processes, soil aquifer treatment, etc.

Indirect potable reuse including groundwater recharge of potable aquifer and surface water reservoir augmentation and potable reuse

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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

Regardless of the reclaimed water use, whether irrigation, IPR, potable reuse, or car washing, the most critical treatment objective is pathogen inactivation. The reclaimed water must not pose an unreasonable risk due to infectious agents if there is human contact, which could occur by whole body contact or ingestion. EPA has established risk assessment methods and criteria that have been used in developing standards and criteria for microbial risks for both drinking water and whole body contact. These risk assessment methods and acceptable levels of risks are described in the Use of Microbial Risk Assessment in Setting U.S. Drinking Water Standards and the draft Recreational Water Quality Criteria (EPA, 1992; 2011). While the potential human health impacts of reclaimed water is the subject of ongoing research, (e.g., WRRF project 10-07, Bio-analytical Techniques to Assess the Potential Human Health Impacts of Reclaimed Water, currently in preparation), additional discussion specific to risk assessment methods and tools specific to water reuse and exposure to reclaimed water are provided in other recent research reports (WRRF, 2007b; 2010a).

6.1.2 What Constituents are Present in a Wastewater Source, and What Level of Treatment is Applicable for Reducing Constituents to Levels That Achieve the Desired Reclaimed Water Quality? Constituents that may be present in wastewater are described in Section 6.2. Numerous studies and fullscale projects have demonstrated that combining several treatment processes in sequence provides multiple barriers to remove almost all constituents to currently-accepted analytical detection levels and does not allow microbial and chemical contaminants to reach finished water at levels of potential concern. In addition, the effective use of pretreatment requirements can prevent introduction of refractory or difficult to treat contaminants to the incoming wastewater in the first place. Section 6.4 discusses the state of treatment technologies to provide extensive control of microbial and chemical contaminants for reuse projects. It is important to note that the NRC’s recent survey of epidemiological studies of reuse concluded that “adverse health effects likely to be associated with use of reclaimed water have not identified any patterns from water reuse projects in the United States” (NRC, 2012).

2012 Guidelines for Water Reuse

The successful record of water reuse installations in the United States and around the world is the result of highly-engineered redundant treatment processes, which assure the safety of human health and the environment based on current standards. However, based on the last two decades of intensive experience in reuse, numerous studies, technology advances, and monitoring of successful projects, it may not always be necessary to provide such high levels of redundancy in the treatment train given the effectiveness and reliability of available technologies. For example, AOP may not be generally necessary when additional treatment will be applied at a drinking water plant, and UV alone can provide removal of the disinfection byproduct NDMA, if needed; UV/AOP prior to discharge to a surface water storage reservoir may also be unnecessary. Excellent reduction of nitrogen and phosphorus nutrients may be essential for reclaimed water discharge to a storage reservoir, whereas these nutrients represent an advantage for certain irrigation applications and might not need to be removed. The allowable concentrations of microbial and chemical constituents in reclaimed water are a function of the specific reuse application or category of reuse. And while these requirements may vary slightly from state to state, they have been designed to be protective of human health given some of the current thinking. Reclaimed water quality standards and practices have evolved, based on both scientific studies and practical experience. In particular, reclamation for potable reuse will meet drinking water standards; thus, it is not necessary to create a national list of concentration limits for specific chemical constituents for indirect or direct potable reuse projects (similar to drinking water MCLs), regardless of whether reclaimed water is part of the supply. Treatment guidelines and drinking water health advisory-type benchmarks for emerging chemicals of potential interest (pharmaceuticals, pesticides, and other “chemicals of emerging concern”) are useful for assisting engineers in design of the multiple barriers that continue to protect the public from health risks.

6.1.3 Which Sampling/Monitoring Protocols are Required to Ensure that Water Quality Objectives are Being Met? The successful record of water reuse installations is also the result of programs that ensure treatment reliability, establish cross-connection controls, manage conveyance and distribution system controls, display

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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

user area controls (such as signage, color-coded pipes and appurtenances, and setback distances), and monitor water quality to ensure safety, as described in Chapter 4. It is also essential to have an appropriate HACCP-type management system; to employ appropriate, reliable, and multi-barrier redundant treatments; and to utilize as much as possible realtime monitoring of surrogates to assure continuous performance. While a number of online methods for performance monitoring are currently being used (e.g., turbidity and chlorine residual), the WRRF has funded additional research on monitoring for reliability and process control for potable reuse projects under project number WRF-11-01, which is anticipated for publication in 2015.

6.2 Wastewater Constituents and Assessing Their Risks

Before a particular treatment process train design can be selected for implementation in a reuse project, it is important to understand which constituents are of concern and in what concentrations. Untreated municipal wastewater contains a range of constituents, from dissolved metals and trace organic compounds to large solids such as rags, sticks, floating objects, grit, and grease. All reuse systems require a minimum of secondary treatment, which addresses large objects and particles, most dissolved organic matter, some nutrients, and other inorganics. However, there are some particles, including microorganisms and dissolved organic and inorganic constituents that remain in the secondary-treated wastewater, and further treatment is most often required before it can be reused. This section provides an overview of the key wastewater constituents that are addressed in reclaimed water treatment systems.

6.2.1 Microorganisms in Wastewater Microorganisms are ubiquitous in nature, and most are not pathogenic to humans. Microorganisms, also called microbes, are diverse and are critical to nutrient recycling in ecosystems. In wastewater treatment systems, which are effectively engineered ecosystems, they act as beneficial decomposers of nutrients and organic matter. Concentrations of microorganisms are typically reported on a logarithmic 6 scale (e.g., 1 million = 10 microorganisms) because they can be present in very high concentrations. Likewise, they can be removed to significant extents, and logarithmic scales help capture these huge ranges

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in concentrations. Removal of microorganisms is typically reported logarithmically, where 1-log indicates 90 percent removal, 2-log is 99 percent removal, 3-log is 99.9 percent removal, 4-log is 99.99 percent removal, and so forth. In addition to beneficial microorganisms, raw domestic wastewater can contain a large variety of pathogenic microorganisms that are derived principally from the feces of infected humans and primarily transmitted by the “fecal-oral” route. A pathogen is a microorganism that causes disease in its host. Most pathogens found in untreated wastewater are known as ‘enteric’ microorganisms; they inhabit the intestinal tract where they can cause disease, such as diarrhea. The source of human pathogens in wastewater is the feces of infected individuals who exhibit disease symptoms, as well as carriers with inapparent infections. Pathogens may also be present in urine, including pathogens that can cause urinary schistosomiasis, typhoid fever, leptospirosis, and some sexually transmitted infections. However, the first three diseases represent very low disease incidence in the United States, and the latter cannot survive for long in wastewater conditions. Thus, pathogens from urine are of low public health risk in water reuse. Table 6-2 lists many of the infectious agents potentially present in raw domestic wastewater. These are classified into three broad groups: bacteria, parasites (parasitic protozoa and helminths), and viruses. Table 6-2 also lists some of the diseases associated with each pathogen. The concentration of pathogens in wastewater varies greatly depending on the health of the general population, as well as the season. Concentrations of some organisms observed in the research are reported in Table 6-2 to provide a general comparison, but available data are sparse due to lack of funding for these types of testing. Water bodies, such as rivers, lakes, streams, landscape impoundments, engineered stormwater channels, groundwater, and swimming pools, can become contaminated from exposure to untreated or inadequately treated domestic sewage and agricultural runoff. Pathogen survival in the aquatic environment is governed by distance of travel, rate of transport, temperature, soil moisture content, humidity, exposure to sunlight, water chemistry (pH, salinity, etc.), and predation by other organisms, but varies greatly from pathogen to pathogen.

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Table 6-2 Infectious agents potentially present in untreated (raw) wastewater Pathogen

Disease

Numbers in Raw Wastewater (per liter)

Bacteria 4

Shigella

Shigellosis (bacillary dysentery)

Up to 10

Salmonella

Salmonellosis, gastroenteritis (diarrhea, vomiting, fever), reactive arthritis, typhoid fever

Up to 10

Vibro cholera

Cholera

Up to 10

Enteropathogenic Escherichia coli (many other types of E. coli are not harmful)

Gastroenteritis and septicemia, hemolytic uremic syndrome (HUS)

Yersinia

Yersiniosis, gastroenteritis, and septicemia

Leptospira

Leptospirosis

Campylobacter

Gastroenteritis, reactive arthritis, Guillain-Barré syndrome

Atypical mycobacteria

Respiratory illness (hypersensitivity pneumonitis)

Legionella

Respiratory illness (pneumonia, Pontiac fever)

Staphylococcus

Skin, eye, ear infections, septicemia

Pseudomonas

Skin, eye, ear infections

Helicobacter

Chronic gastritis, ulcers, gastric cancer

5 5

4

Up to 10

Protozoa 2

Entamoeba

Amebiasis (amebic dysentery)

Up to 10

Giardia

Giardiasis (gastroenteritis)

Up to 10

Cryptosporidium

Cryptosporidiosis, diarrhea, fever

Up to 10

Microsporidia

Diarrhea

Cyclospora

Cyclosporiasis (diarrhea, bloating, fever, stomach cramps, and muscle aches)

Toxoplasma

Toxoplasmosis

5 4

Helminths 3

Ascaris

Ascariasis (roundworm infection)

Up to 10

Ancylostoma

Ancylostomiasis (hookworm infection)

Up to 10

Necator

Necatoriasis (roundworm infection)

Ancylostoma

Cutaneous larva migrams (hookworm infection)

Strongyloides

Strongyloidiasis (threadworm infection)

Trichuris

Trichuriasis (whipworm infection)

Taenia

Taeniasis (tapeworm infection), neurocysticercosis

Enterobius

Enterobiasis (pinwork infection)

Echinococcus

Hydatidosis (tapeworm infection)

3

2

Up to 10

Viruses Enteroviruses (polio, echo, coxsackie, new enteroviruses, serotype 68 to 71)

Gastroenteritis, heart anomalies, meningitis, respiratory illness, nervous disorders, others

Hepatitis A and E virus

Infectious hepatitis

Adenovirus

Respiratory disease, eye infections, gastroenteritis (serotype 40 and 41)

Up to 10

Rotavirus

Gastroenteritis

Up to 10

Parvovirus

Gastroenteritis

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Up to 10

6 5

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Table 6-2 Infectious agents potentially present in untreated (raw) wastewater Pathogen

Disease

Numbers in Raw Wastewater (per liter)

Viruses Astrovirus

Gastroenteritis

Caliciviruses (including Norovirus and Sapovirus)

Gastroenteritis

Coronavirus

Gastroenteritis

9

Up to 10

(Sources: NRC, 1996; Sagik et. al., 1978; Hurst et. al., 1989; WHO, 2006; Feachem et al., 1983, Mara and Silva, 1986; Oragui et al., 1987, Yates and Gerba, 1998, da Silva et al., 2007, Haramoto et al., 2007, Geldreich, 1990; Bitton, 1999; Blanch and Jofre, 2004; and EPHC, 2008)

The main potential routes of waterborne disease transmission, in the context of water reclamation, include ingestion or consumption of contaminated water or foods from vectors via hand-to-mouth contact, or by inhalation from breathing in a mist or aerosolized water containing suspended pathogens. The potential transmission of infectious disease by pathogenic agents is the most common concern associated with reuse of treated municipal wastewater. Fortunately, treatment technologies are capable of removing pathogens from water to below detection limits. However, it is still useful to understand what pathogenic microorganisms are potentially present in wastewater so that appropriate treatment can be applied. The following sections provide information on the major classes of microorganisms in wastewater.

6.2.1.1 Protozoa and Helminths Parasites can be excreted in feces as spores, cysts, oocysts, or eggs, which are robust and resistant to environmental stresses such as desiccation, heat, freezing, and sunlight. Most parasite spores, cysts, oocysts, and eggs range in size from 1 μm to over 60 μm (larger than bacteria). Helminths can be present as the adult organism, larvae, eggs, or ova. The eggs and larvae, which range in size from about 10 μm to more than 100 μm, are resistant to environmental stresses. The occurrence of these microorganisms in reclaimed water has been the subject of recent research (WRRF, 2012b), which confirms that eliminating protozoa and helminthes from wastewater can be achieved through either a “removal” or an “inactivation” process (WRRF, 2012b). In reclaimed water, protozoa and helminths can be physically removed by sedimentation or filtration (Section 6.4) because of their relatively large size. Protozoa and helminths may be resistant to disinfection by chlorination or other chemical

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disinfectants, but may be inactivated using UV disinfection (Section 6.4.3.2) by inducing mutations in their DNA. Recent research on development of molecular assays that can rapidly discriminate between infectious cysts and cysts unable to cause an infection in reclaimed water have confirmed this mode of disinfection (WRRF, 2012c).

6.2.1.2 Bacteria Bacteria are microscopic organisms ranging from approximately 0.2 to 10 μm in length. Many types of harmless bacteria colonize in the human intestinal tract and are routinely shed in the feces. Pathogenic bacteria are also present in the feces of infected individuals; therefore, municipal wastewater can contain a wide variety and concentration range of bacteria, including those pathogenic to humans. The numbers and types of these agents are a function of their prevalence in the animal and human community from which the wastewater is derived. Bacterial levels in wastewater can be significantly lowered through removal or inactivation processes, which typically involve the physical separation of the bacteria from the wastewater through sedimentation and/or filtration. Due to density considerations, bacteria do not settle as individual cells or even colonies. Bacteria can adsorb to particulate matter or floc particles, and these particles settle during sedimentation, secondary clarification, or during an advanced treatment process such as coagulation/ flocculation/sedimentation. Bacteria can also be removed by using a filtration process that includes sand filters, disk (cloth) filters, or membrane processes. Bacteria can also be inactivated by disinfection. Both filtration and disinfection are discussed further in Section 6.4.

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6.2.1.3 Viruses Viruses occur in various shapes and range in size from 0.01 to 0.3 μm, a fraction of the size of bacteria. Bacteriophages are viruses that infect bacteria; they have not been implicated in human infections and are often used as indicators. Coliphages are host-specific viruses that infect coliform bacteria. Enteric viruses multiply in the intestinal tract and are released in fecal matter of infected persons. Not all types of enteric viruses have been determined to cause waterborne disease, but more than 100 different enteric viruses are capable of producing infections or disease. In general, viruses are more resistant to environmental stresses than many bacteria, and some viruses persist for only a short time in wastewater. Similar to bacteria and protozoan parasites, viruses can be physically removed or inactivated (Myrmel et al., 2006). However, due to the relatively small size of typical viruses, sedimentation and filtration processes are less effective at removal. Significant virus removal can be achieved with ultrafiltration membranes, possibly in the 3- to 4-log range. However, for viruses, inactivation is generally considered the more important of the two main reduction methods and is often accomplished by UV disinfection. Interestingly, disinfection of viruses requires relatively higher doses of UV compared to inactivation of bacteria and protozoa. While monitoring specific virus pathogens in wastewater samples would provide more reliable information for risk assessments of waterborne viral infections, direct monitoring of several viral pathogens in water is challenging and impractical, despite the recent development of real-time quantitative polymerase chain reaction (PCR) analyses (LeCann et al. 2004; Van den Berg et al. 2005). Until more data regarding the detection of active, infectious viruses is available, data generated from seeded studies to evaluate the efficacy of wastewater treatment processes should be carefully evaluated to provide treatment designs that remove infectious viruses.

6.2.1.4 Aerosols Aerosols are particles less than 50 μm in diameter that are suspended in air. Viruses, most pathogenic bacteria, and pathogenic protozoa are in the respirable size range; hence, inhalation of aerosols is a possible direct means of human infection. Aerosols are most often a concern where improperly-treated reclaimed water is applied to urban or agricultural sites with

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sprinkler irrigation systems or where it is used for cooling water make-up. Infection or disease may be contracted directly through inhalation or indirectly from aerosols deposited on surfaces, such as food, vegetation, and clothes. The infective dose of some pathogens is lower for respiratory infections than for infections via the gastrointestinal tract; thus, for some pathogens, inhalation may be a more likely route for disease transmission than either contact or ingestion. Thus, for intermittent spraying of disinfected reclaimed water, occasional inadvertent contact should pose little health hazard from inhalation. Cooling towers issue aerosols continuously and may present a greater concern if the water is not properly disinfected. In either case, aerosol exposure is limited through design or operational controls that are discussed in detail in the 2004 guidelines (EPA, 2004).

6.2.1.5 Indicator Organisms It is important to distinguish between the actual pathogens versus indicator microorganisms that are used to measure treatment performance of a particular treatment system with respect to addressing pathogenic organisms from fecal contamination. Indicators are not themselves dangerous to human health, but are used to indicate the likelihood of occurrence of a health risk. The variety and often lower concentrations of pathogenic microorganisms in environmental waters, necessitating concentration combined with specialized analytical methodologies for pathogen detection, makes it difficult for the typical wastewater laboratory to run such tests. Regulatory agencies have historically required routine monitoring of other more abundant and more easily detected fecal bacteria as indicators of the presence of fecal contamination. In some states, total coliform bacteria are used as an indicator; however, in most states that have specific regulations, the microbiological safety of reclaimed water is evaluated by daily monitoring of fecal coliform bacteria in disinfected effluent based on a single, 100-mL grab sample. Some states do require monitoring of certain pathogens, such as Giardia and Cryptosporidium requirements in Florida, Arizona, and California. Monitoring for viruses is also required for reclaimed water used for irrigation of food-crops in North Carolina. The specific monitoring requirements for these states are provided in Section 4.5.2. In addition, pathogen analyses are sometimes conducted as part

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of special studies or by proactive utilities that wish to confirm the treatment reliability of the process used to produce reclaimed water. More often, indicators including total coliforms; fecal coliforms, a subset of total coliforms; Escherichia coli (E. coli); enterococci; and coliphage are used to validate performance of treatment and the quality of the final reclaimed water quality. The main drawback to using microbial indicators is that they are somewhat limited in their ability to predict the presence of pathogens. Also, all current uses of microbial indicators employ cultivation methods that delay results for at least 24 hours. For example, nonpathogenic coliforms, such as those that may be found in soil, can grow in water under certain conditions, leading to positive results that may not be indicative of wastewater impact. Additionally, coliform bacteria do not adequately reflect the occurrence of pathogens in disinfected reclaimed water due to their relatively high susceptibility to chemical disinfection and failure to correlate with protozoan parasites such as Cryptosporidium and enteric viruses (Bonadonna, et al., 2002; Havelaar et al., 1993). Alternative microbiological indicators have been suggested for evaluation of wastewater, drinking water, and environmental waters, including Enterococcus, Clostridium, and coliphages. But there have been only a few studies of reclaimed water in which the levels of indicator organisms have been directly compared to those of viral, bacterial, or protozoan pathogens at each stage of treatment, and additional research on this topic is needed (Harwood et al., 2005). Analytical methods for actual pathogen monitoring continue to evolve, and recent studies have not relied solely on the traditional standard culture methods (Fox and Drewes, 2001; Sloss et al., 1996; Sloss et al., 1999; Yanko 1999). PCR is now commonly used to study pathogens and indicators by detecting the DNA or RNA in the environment. PCR is useful because the methods are sensitive. In addition, PCR can be much less expensive and time consuming than traditional pathogen methods, and culture methods are not currently available for some pathogens. Recent studies have reported pathogen

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DNA and RNA in secondary and advanced municipal wastewater effluents, some recycled water, groundwater, and in ocean water impacted by wastewater discharges (Aw and Gin, 2010; De Roda et al., 2009; Hunt et al., 2010; Jjemba et al., 2010; Symonds et al., 2009, da Silva et al., 2008; da Silva et al., 2007; Haramoto et al, 2007). However, it is important to emphasize that PCR does not determine pathogen viability or infectivity; it only indicates the existence of DNA or RNA derived from the microorganisms. There is ongoing research using PCR-based detection methods into how this information can be used to evaluate potential risk; quantitative PCR in particular has potential to provide data for quantitative microbial risk assessment (QMRA), however, it must be kept in mind that indicators only evaluate “potential” risk. These indicators have not been related to any epidemiological risks except for E. coli and enterococci in recreational settings (Section 6.3.1). Additionally, evaluation of certain disinfection processes is particularly limited with respect to using molecular tools and indicators, although molecular viability methods are emerging.

6.2.1.6 Removal of Microorganisms Removal of indicators and pathogens can be demonstrated both by challenge testing and operational monitoring. Challenge testing allows large log removals to be demonstrated by spiking influent concentrations with higher than normal microorganism concentrations to allow detection in the effluent. Because detected concentrations of actual pathogens tend to approach or fall at the lowest detectable concentrations of current analytical methods, further research in this area could provide greater confidence in the sensitivity of operational monitoring. Table 6-3 presents an indicative range of microbial log reductions reported in the literature for different treatment processes, which are further discussed in Section 6.4. These ranges are intended to present relative removals; they should not be used as the basis of design for treatment schemes.

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Type of Microorganism Bacteria X X X Protozoa and helminths X X Viruses X X 1 Indicative Log Reductions in Various Stages of Wastewater Treatment Secondary treatment 1-3 0.5 - 1 0.5 - 2.5 1-3 0.5 - 2 0.5 - 1.5 0.5 - 1 2 Dual media filtration 0-1 0-1 1-4 0-1 0.5 - 3 1-3 1.5 - 2.5 Membrane filtration (UF, 4 - >6 >6 2 - >6 >6 2 - >6 >6 4 - >6 3 NF, and RO) Reservoir storage 1-5 N/A 1-4 1-5 1-4 3-4 1 - 3.5 Ozonation 2-6 0 - 0.5 2-6 2-6 3-6 2-4 1-2 UV disinfection 2 - >6 N/A 3 - >6 2 - >6 1 ->6 3 - >6 3 - >6 Advanced oxidation >6 N/A >6 >6 >6 >6 >6 Chlorination 2 - >6 1-2 0 - 2.5 2 - >6 1-3 0.5 - 1.5 0 - 0.5

Helminths

Cryptosporidium parvum

Giardia lamblia

Enteric viruses

Enteric bacteria (e.g., Campylobacter)

Phage (indicator virus)

Clostridium perfringens

Escherichia coli (indicator bacteria)

Table 6-3 Indicative log removals of indicator microorganisms and enteric pathogens during various stages of wastewater treatment Indicator microorganisms Pathogenic microorganisms

X

0-2 2-3 >6 1.5 - >3 N/A N/A N/A 0–1

(Sources: Bitton, 1999; EPHC, 2008; Mara and Horan, 2003; NRC, 1998; NRC, 2012; Rose et al., 1996; Rose, et al., 2001; EPA, 1999, 2003, 2004; WHO, 1989) 1

Reduction rates depend on specific operating conditions, such as retention times, contact times and concentrations of chemicals used, pore size, filter depths, pretreatment, and other factors. Ranges given should not be used as design or regulatory bases—they are meant to show relative comparisons only. 2 Including coagulation 3 Removal rates vary dramatically depending on the installation and maintenance of the membranes. N/A = not available

6.2.1.7 Risk Assessment of Microbial Contaminants While most microbes are harmless or beneficial, some are extremely dangerous—these are sometimes referred to as biological agents of concern (BAC). All BAC can cause serious and often fatal illness, but they differ in their physical characteristics, movement in the environment, and process of infection. QMRA measures microbes’ behavior to identify where they can become a danger and estimate the risk (including the uncertainty in the risk) that they pose to human health. QMRA has four stages, based on the National Academy of Sciences framework for Quantitative Risk Analysis, but is modified to account for the properties of living organisms like BAC (NAS, 1983):

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Hazard Identification: This process describes a microorganism and the disease it causes, including symptoms, severity, and death rates from the microbe; it identifies sensitive populations that are particularly prone to infection. Dose-Response: Establishing the relationship between the dose (number of microbes received) and the resulting health effects is a critical step in the process. Data sets from human and animal studies allow the construction of mathematical models to predict dose-response. Exposure Assessment: This step describes the pathways that allow a microbe to reach individuals and cause infection (through the air, through drinking water, etc.). It is necessary to determine the size and

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duration of exposure by each pathway as well as estimate the number of people exposed and the categories of people affected. Risk Characterization: The final step of the process integrates information from previous steps into a single mathematical model to calculate risk—the probability of an outcome such as infection, illness, or death. Because the first three steps do not provide a single value but instead offer a range of values for exposure, dose, and hazard, risk needs to be calculated for all values across those ranges. This is accomplished using Monte Carlo analysis, and the result is a full range of possible risks, including average and worstcase scenarios. These are the risks decision-makers evaluate when defining regulatory policy and the risks that scientists review to determine where additional research is needed to obtain better information. Additional information on QMRA is available in a 2006 report to the European Commission entitled QMRA: Its Value for Risk Management (Medema and Ashbolt, 2006).

6.2.2 Chemicals in Wastewater All water is ultimately reused in the natural cycle and contains detectable levels of various chemicals. Rainwater collects chemicals from atmospheric contact; groundwater contains inorganics from the geology; surface waters collect natural products and possibly pesticides and other chemicals from runoff and discharges from industrial and other facilities. Wastewater contains chemicals, and the number and concentrations of the constituents detected depends on many factors, including the municipal source, the condition of the collection system, and the treatment processes employed.

6.2.2.1 Inorganic Chemicals Inorganic constituents in wastewater include metals, salts, oxyhalides, nutrients, and, potentially, engineered nanomaterials. The concentrations of inorganic constituents in reclaimed water depend mainly on the source of wastewater and the degree of treatment the water has received. The presence of inorganic constituents may affect the acceptability of reclaimed water for different reuse applications. Wastewater treatment using existing technology can generally reduce many trace elements to below recommended maximum levels for irrigation and drinking water. In general, the health hazards

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associated with the ingestion of inorganic constituents, either directly or through food, are well established. Under the SDWA, the EPA has set MCLs for contaminants in drinking water. Aggregate measures of most inorganic constituents in water are TDS and conductivity, although they both may include some organic constituents, as well. Residential use of water typically adds about 300 mg/L of dissolved inorganic solids, although the amount added can range from approximately 150 mg/L to more than 500 mg/L (Metcalf & Eddy, 2003). Metals and Salts. Regulatory statutes for treated wastewater discharge and industrial pretreatment regulations promulgated through the CWA specifically target toxic metals; as a result, most municipal effluents have concentrations of toxic metals below public health guidelines and standards. Boron, a metalloid in detergents, can be present in domestic wastewater, but concentrations generally are well below EPA health advisory and WHO guidelines. Boron can be toxic to some plants at concentrations approaching levels that may be present in reclaimed water, which can limit the types of plants that can be irrigated with the water. Likewise, salts (measured as TDS) present in reclaimed water generally do not exceed thresholds of concern to human health but can affect crops [Israel/Jordan-Brackish Irrigation]. Salinity can cause leaf burn, reduce the permeability of claybearing soils, and affect soil structure. Salinity also can cause aesthetic concerns (e.g., taste in potable reuse or residues in car washing operations), scaling, and corrosion. Salinity can be removed in treatment, but options tend to be costly, and liquid waste (brine) disposal is an issue. Salinity management in irrigation reuse applications is described further in Chapter 3. Oxyhalides. Oxyhalides of concern in water reuse include bromate, chlorate, and perchlorate. Bromate can be created when bromide-containing wastewater is ozonated; therefore, treatment facilities must be designed and operated properly to minimize oxyhalide formation during treatment. Bromate, chlorate, and perchlorate can be derived from household bleach. Perchlorate, a component of propellants, can bioaccumulate in certain plants and must be managed in irrigation. Nutrients. Nitrogen and phosphorus from human waste products can pose environmental and health concerns but can also be beneficial in certain irrigation

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applications. Therefore, the need to remove nutrients during treatment for reuse depends on the intended use of the product water. Engineered Nanomaterials. Nanomaterials are materials with morphological features on the nanoscale (1 nm = 10-9 m), that often have special properties stemming from their dimensions. Nanomaterials have one or more dimensions ranging from 1 to 100 nm: nanofilms (one dimension), nanotubes (two dimensions), and nanoparticles (three dimensions). Larger particles, such as zeolites (1,000 to 10,000 nm, or 1 to 10 µm), may also be considered nanomaterials because their pores fall into the nanoscale size range (0.4 to 1 nm). Nanomaterials can be organic, inorganic, or a combination of organic and inorganic components. Nanotechnology promises exciting new possibilities in water treatment and water quality monitoring. Nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle-enhanced filtration are categories of novel nanotechnologies that may change water treatment and water quality monitoring (Savage and Diallo, 2005). Indeed, research is ongoing to develop novel membranes for water and wastewater treatment (including desalination) built around nanotube pores. Many consumer products now contain engineered nanomaterials because of their unique surface chemistry, catalytic properties, strength, weight, and conductive properties compared to their larger-scale counterparts (National Science and Technology Council, 2011; WEF, 2008). The market for nanomaterials in consumer products is taking off—the United Nations Environment Programme projects that the market for nanomaterial-containing products could exceed $2 trillion by 2014 (United Nations Environment Programme, 2007). While naturally-occurring particles in this range include viruses and natural organic matter, the more recent introduction of engineered nanomaterials into the environment from consumer products poses new questions about the fate and potential environmental and health effects of these materials. Preliminary studies to determine the health effects caused by exposure to nanomaterials and the risk assessment, toxicity, and treatability of nanomaterials show inconsistent results, warranting ongoing investigation (WEF, 2008). To date, no link has been made between

2012 Guidelines for Water Reuse

trace levels of engineered nanoparticles in wastewater and an adverse human health impact (O’Brien and Cummins, 2010). Because most engineered nanoparticles in municipal wastewater originate from household and personal care products, direct exposure in the household itself is likely far greater than from potential exposure in water reuse. However, potential ecotoxicological risk posed by the release of nanoparticles to surface waters highlights the need for guidance and restriction on the usage and disposal of nanomaterial-containing commercial products (O’Brien and Cummins, 2010). A review of research on the relevance of nanomaterials in water reuse has been compiled (WRRF, 2012d). Limited research has been conducted on their fate in wastewater treatment, but initial findings suggest that engineered nanoparticles will associate with biosolids or remain in effluents, depending on their size and surface chemistry, as well as the type of treatment process employed (Kaegi et al., 2011; Kiser et al., 2009; and WEF, 2008).

6.2.2.2 Organics The organic composition of raw wastewater includes naturally-occurring humic substances, fecal matter, kitchen wastes, liquid detergents, oils, grease, consumer products, industrial wastes, and other substances that, in one way or another, become part of the sewage stream. The level of treatment for these constituents in reclaimed water is related to the end use of reclaimed water. Some of the adverse effects associated with organic substances include: 

Aesthetic effects. Organics may malodorous and impart color to the water.



Clogging. Particulate matter may clog sprinkler heads or accumulate in soil and affect permeability.



Proliferation of microorganisms. Organics provide food for microorganisms.



Oxygen consumption. Upon decomposition, organic substances deplete the DO content in streams and lakes. This negatively impacts the aquatic life that depends on the oxygen supply for survival.



Use limitation. Many industrial applications cannot tolerate water that is high in organic content.

be

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Disinfection effects. Organic matter can interfere with chlorine, ozone, and UV disinfection, thereby making them less available for disinfection purposes. Further, chlorination may result in formation of potentially harmful chlorinated DBPs.



Health effects. Ingestion of water containing certain organic compounds may result in acute or chronic health effects.

The detection of a variety of organic chemicals in municipal wastewater effluent has raised concerns about the potential presence of wastewater-derived chemical contaminants in reclaimed water as well as about their health effects. And, for some reuse applications, regulatory agencies and utilities have struggled with this issue of wastewater-derived compounds, some of which are often present at extremely low concentrations. Because many of these compounds are not currently regulated, current research has focused on the composition of highly processed wastewaters to identify residual chemicals that might be a health concern, determine what studies would be needed as a basis for risk assessment, and develop lists of compounds for which more information is needed to assess the potential human health concerns (WRRF, 2012e). Additionally, the WRRF has funded work on identification and validation of surrogate parameters and analytical methods for wastewater-derived contaminants to predict removal of wastewater-derived contaminants in reclaimed-water treatment systems (WRRF, 2008). Parameters that have historically been used for this purpose and can serve as aggregate measures of organic matter include TOC, dissolved organic carbon (DOC) (that portion of the TOC that passes through a 0.45-µm pore-size filter), particulate organic carbon (POC) (that portion of the TOC that is retained on the filter), BOD, and chemical oxygen demand (COD). These measures are indicators of treatment efficiency and water quality for many nonpotable uses of reclaimed water. Organic compounds in wastewater can be transformed into DBPs where chlorine is used for disinfection purposes. There are strong associations between DBP exposure and bladder cancer among individuals who carry inherited variants in three genes (GSTT1, GSTZ1, and CYP2E1), the code for key enzymes that metabolize DBPs (Freeman, 2010; Cantor et al.,

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2010). In the past, most attention was focused on the trihalomethane (THM) compounds; a family of organic compounds typically occurring as chlorine or brominesubstituted forms of methane. Chloroform, a commonly found THM compound, has been implicated in the development of cancer of the liver and kidney. Haloacetic acids (HAAs) are another undesirable byproduct of chlorination with similar health effects. Improved analytical capabilities to detect extremely low levels of chemical constituents in water have resulted in identification of several health-significant chemicals and DBPs in recent years. For example, the carcinogen NDMA is present in sewage and is also produced when reclaimed water is disinfected with chlorine or chloramines (Mitch et al., 2003). And because chlorination of wastewater is still the most commonly used form of wastewater disinfection, research to further address the challenge of DBP in de facto reuse is a critical need. In some planned reuse applications, the concentration of NDMA present in reclaimed water exceeds action levels set for the protection of human health in drinking water, even after RO treatment. To address concerns associated with DBPs and other trace organics in reclaimed water, several utilities in California have installed UVAOP for treatment of RO permeate to address NDMA [US-CA-Vander Lans; US-CA-Orange County; US-CASan Diego].

6.2.2.3 Trace Chemical Constituents Sophisticated analytical instrumentation makes it possible to identify and quantify extremely low levels of individual inorganic and organic constituents in water. Examples include gas chromatography/tandem mass spectrometry (GC/MS/MS) and high-performance liquid chromatography/mass spectrometry (HPLC/MS). These analyses are costly and may require extensive and difficult sample preparation, particularly for nonvolatile organics. Advancements in these and other analytical chemistry techniques have enabled the quantification of chemicals in water at parts per trillion (ppt) and even parts per quadrillion levels. With further analytical advancements, nearly any chemicals will be detectable in environmental waters, wastewater, reclaimed water, and drinking water in the future, but the human and environmental health relevance of detection of diminishingly low concentrations remains a greater challenge to evaluate. As analytical techniques have improved, a number of anthropogenic chemical compounds that are not

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commonly regulated have been detected in drinking water, wastewater effluent, or environmental waters, generally at very low levels. Detection of these compounds does not imply that they have been recently released to the environment—many have likely been in the environment for decades. This broad group of individual chemicals and classes of compounds present at trace concentrations is sometimes termed contaminants of emerging concern (CECs), TrOCs, or microconstituents. This broad group of CECs can include groups of compounds categorized by end use (e.g., pharmaceuticals, nonprescription drugs, personal care products, household chemicals, food additives, flame retardants, plasticizers, and biocides), by environmental and human health effect, if any (e.g., hormonally active agents, endocrine disrupters [EDs], or endocrine disrupting compounds [EDCs]), or by type of compound (e.g., chemical vs. microbiological, phenolic vs. polycyclic aromatic hydrocarbons). Contaminants under these sub-groupings that are not regulated under national drinking water standards may be on the Drinking Water Contaminant Candidate List (CCL), including some known EDCs, which include chemicals shown to disrupt animal endocrine systems, as well as those with adverse human health interactions. Table 6-4 provides categories of compounds which may be detectable in reclaimed water. Although trace chemical constituents are “pollutants” when they are found in the environment at concentrations above background levels, they are not necessarily “contaminants” (that is, found in the environment at levels high enough to induce ecological and/or human health effects). Experts have struggled to agree on a term that captures the range of constituents because the public often finds terms such

as CEC confusing or alarming, as described in Chapter 6. However, describing the numerous constituents by sub-group or as individual chemicals can likewise cause confusion, because these are also not well understood by the general public. Debate and discussion is ongoing in the water community about how to discuss trace chemical compounds, including terminology and relative risk. Removal of Trace Chemical Constituents. As reclaimed water is considered a source for more and more uses, including industrial process water or potable supply water, the treatment focus has expanded far beyond secondary treatment and disinfection to include treatment for other contaminants, such as metals, dissolved solids, and trace chemical constituents. Chemical constituents are amenable to treatment depending on the physiochemical properties of the compounds and the removal mechanisms of particular treatment processes. EPA has released a report with results of an extensive literature review of published studies of the effectiveness of various treatment technologies for CECs (EPA, 2010). The results of this literature review are also available in a searchable database, “Treating Contaminants of Emerging Concern—A Literature Review Database” (EPA, 2010). EPA developed this information to provide an accessible and comprehensive body of historical information about current CEC treatment technologies. Given the wide range of properties represented by trace chemical constituents, there is no single treatment process that provides an absolute barrier to all chemicals. To minimize their presence in treated water, a sequence of diverse treatment processes capable of tackling the wide range of physiochemical

Table 6-4 Categories of trace chemical constituents (natural and synthetic) potentially detectable in reclaimed water and illustrative example chemicals (NRC, 2012) End use Category Industrial chemicals Pesticides, biocides, and herbicides Natural chemicals Pharmaceuticals and metabolites Personal care products Household chemicals and food additives Transformation products 2012 Guidelines for Water Reuse

Examples 1,4-Dioxane, perflurooctanoic acid, methyl tertiary butyl ether, tetrachloroethane Atrazine, lindane, diuron, fipronil Hormones (17β-estradiol), phytoestrogens, geosmin, 2-methylisoborneol Antibacterials (sulfamethoxazole), analgesics (acetominophen, ibuprofen), betablockers (atenolol), antiepileptics (phenytoin, carbamazepine), veterinary and human antibiotics (azithromycin), oral contraceptives (ethinyl estradiol) Triclosan, sunscreen ingredients, fragrances, pigments Sucralose, bisphenol A (BPA), dibutyl phthalate, alkylphenol polyethoxylates, flame retardants (perfluorooctanoic acid, perfluorooctane sulfonate) NDMA, HAAs, and THMs 6-13

Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

properties is needed (Drewes and Khan, 2010). Fullscale and pilot studies have demonstrated that this can be accomplished by combinations of different processes: biological processes coupled with chemical oxidation or activated carbon adsorption, physical separation (RO) followed by chemical oxidation, or natural processes coupled with chemical oxidation or carbon adsorption. The question is whether all of these technologies are necessary to assure health protection or whether a particular sequence is over-treatment, especially when the water will be returned to the environment via a reservoir or aquifer. The water, therefore, will likely be degraded to some degree prior to being withdrawn for further drinking water treatment. A recent survey of the fate of pharmaceuticals and personal care products (PPCPs) in WWTPs revealed that many EDCs are present at mg/L concentrations and are not significantly removed during conventional wastewater treatment processes (Miège et al., 2008). Some removal or chemical conversion can be expected during drinking water disinfection (i.e., sulfamethoxazole, trimethoprim estrone, 17β-estradiol, 17α-ethinylestradiol, acetaminophen, triclosan, bisphenol A, and nonylphenol). Chlorine, chlorine dioxide, and ozone disinfection are oxidation processes (Alum et al., 2004; Huber et al., 2005); among the three oxidants, ozone is the most reactive with many trace organic chemicals. Activated carbon adsorption can readily remove many organic compounds from water, with the exception of some polar water-soluble compounds, such as iodinated contrast agents and the antibiotic sulfamethoxazole (Adams et al., 2002; Westerhoff et al., 2005). Although they are very effective, AOP treatment processes are inefficient for oxidizing trace chemical constituents because they are energy intensive and involve random reactions with much of the TOC in addition to the target chemicals present in only minute quantities. Compared to ozone treatment alone, AOPs provide only a small increase in removal efficacy (Dickenson et al., 2009). Low-pressure membranes, such as MF and ultrafiltration (UF), have pore sizes that are insufficient to retain trace chemical constituents; however, some hydrophobic compounds can still adsorb onto MF and UF membrane surfaces providing some short-term attenuation of the hydrophobic compounds and TOC. However, high-pressure membranes, such as RO and

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nanofiltration (NF), are very effective in the physical separation of a variety of pharmaceuticals and other organics and inorganics from water (Bellona et al., 2008). Low-molecular-weight organics are problematic for high-pressure membranes, and the disposal of the concentrate (brine) with elevated levels of trace chemical constituents can be an issue. Natural processes, such as riverbank filtration (RBF) and SAT, can be employed either as an additional treatment step for wastewater reclamation or as a pre-treatment to subsequent drinking water treatment (Amy and Drewes, 2007; Hoppe-Jones et al. 2010). RBF and SAT are very effective in attenuating a wide range of chemicals by sorption and biotransformation processes in the subsurface but are limited in attenuating refractory compounds, such as antiepileptic drugs or chlorinated flame retardants (Drewes et al., 2003). AOP processes are being researched for their ability to remove organic compounds. For example, while UV photolysis is generally not an effective treatment option for removing organic compounds, UV photolysis in combination with H2O2 achieves high removal rates of a variety of potential EDCs, including bisphenol A, ethinyl estradiol, and estradiol (Rosenfeldt and Linden, 2004). Table 6-5 presents a summary of indicative reductions of organic chemical concentrations. Data presented are intended to present relative removals but should not be used as a design or regulatory basis. Scheme proponents must validate the treatment technology for the specific application and operational conditions. Risk Assessment of Trace Chemical Constituents. Because WWTPs using conventional treatment processes cannot remove trace organic chemicals completely, wastewater discharge can introduce some of these constituents into receiving environments. Thus, in de facto reuse, chemical constituents can be introduced into drinking water supplies (Benotti et al., 2009). Detection of trace chemical constituents in drinking water systems and environmental waters raise understandable concerns about the potential implications for public and ecological health. Research organizations around the world, including EPA, are exploring these implications and assessing the risks with respect to acute, chronic illness, and sequelae. Although a number of comprehensive studies have been conducted to address the concern about

2012 Guidelines for Water Reuse

Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

potential human health risks of unknown and unidentified trace level chemicals in reclaimed water (Nellor et al., 1984; Sloss et al., 1996; Anderson et al., 2010), there is currently no definitive documentation of risk with respect to trace chemicals for the use of reclaimed water to augment drinking water supplies. On the basis of available information, there is no indication that health risks from using highly-treated reclaimed water for potable purposes are greater than those from using existing water supplies (NRC, 2012). A recent report by the Global Water Research Coalition (GWRC) synthesized results of nine recently published reports addressing the occurrence and potential for human health impacts of pharmaceuticals in the drinking water system (GWRC, 2009). The report concludes that there is no known impact on human health due to pharmaceutical exposure in drinking water, and that if a person consumed drinking water with the reported levels of pharmaceuticals, that person would consume only 5 percent (or less) of one daily therapeutic dose (i.e., a single pill) of an individual pharmaceutical over his or her whole lifetime. Further, a recent report from a WHO expert panel concluded that the risk of adverse human health effects from exposure to the trace levels of pharmaceuticals in drinking water is considered to be unlikely (WHO, 2011); this report did not assess nonpharmaceutical trace chemicals. Public exposure to trace chemical constituents in water reuse for irrigation or other types of nonpotable reuse is negligible. In planned potable reuse, the treatment technologies employed in the United States ensure that concentrations of trace chemicals are at extremely low levels, often below analytical detection limits. And, in fact National Academy of Sciences 2012 Report on water reuse (Water Reuse: Expanding the Nation’s Water Supply Through the Reuse of Municipal Wastewater) presented a risk comparison between potable reuse projects and de facto reuse scenarios (as described in Section 3.7), concluding that potable reuse scenarios have reduced risk of pathogen exposure and lower or equivalent risk of chemical contaminant exposure compared to existing water supplies (NRC, 2012). While the risk associated with trace chemical constituents in drinking water is indeed very low, the water sector continues to investigate the issue and invest in precautionary treatment technologies.

2012 Guidelines for Water Reuse

Because a human health risk of zero is not an achievable condition with exposure of any level, it is necessary to reach a consensus on upper bound de minimis risk goals that can be the basis for design and operation of planned potable reuse facilities. The greater impact of trace chemical constituents may be the ecological effects from the presence of chemicals in wastewater discharges and stormwater runoff to surface waters. Recent concern over ecological effects of discharged chemical constituents is primarily from studies in the 1990s of surface waters receiving treated municipal wastewater where feral fish in proximity of the discharge were found to have altered reproduction strategies and high incidences of hermaphrodism (Sumpter and Johnson, 2008). When advanced wastewater treatment, which includes RO, is used, almost all microconstituents can be effectively removed, and the RO effluent poses no hormonal threat to tissue cultures and live fish (WRRF, 2010b). Thus, while many environmental monitoring programs are underway, toxicological studies conducted at environmentally relevant concentrations are not likely to provide much information due to the very low hypothetical risks at the trace concentrations that are detected, the difficulty in conducting chronic studies, and the large margins of exposures. In response to uncertainties that may be associated with potential risks in potable reuse applications, adoption of appropriate treatment technologies has been employed to minimize exposure of humans to wastewater-derived trace chemical constituents. Many analytical studies have been conducted to identify the few residual chemicals that may pass through advanced treatment. Residual TOC levels, which can be considered a surrogate for trace chemical constituents in planned potable reuse finished water, are usually a fraction of a milligram per liter. Additional information on guidance for developing monitoring programs that assess potential CEC threats from water reuse provided by the SWRCB is provided in the regulatory section that follows, Section 6.3 (SWRCB, 2011; Anderson et al., 2010). Additional research on evaluating and explaining the relative human health risks related to the reuse of reclaimed water continue to be funded, and in 2012 the WRRF published a series of reports in which quantitative relative risk assessments were conducted at the Montebello Forebay [US-CA-Los Angeles County].

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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health Table 6-5 Indicative percent removals of organic chemicals during various stages of wastewater treatment Percent Removal Pharmaceuticals Treatment Secondary (activated sludge) Soil aquifer treatment

B(a)p

Antibiotics

nd

1

Hormones

DZP

CBZ

DCF

IBP

PCT

Steroid

10–50

nd



10–50

>90

nd

>90

nd

nd

nd

25–50

>90

>90

>90

Aquifer storage

nd

50–90

10–50



50–90

50–90

Microfiltration

nd

<20

<20

<20

<20

Ultrafiltration/ powdered activated carbon (PAC)

nd

>90

>90

>90

Nanofiltration

>80

50–80

50–80

Reverse osmosis

>80

>95

PAC

>80

Granular activated carbon Ozonation

>80

Advanced oxidation High-level ultraviolet Chlorination

>80

2

Anabolic

3

Fragrance

NDMA

nd

50–90



>90

nd

>90

>90

Nd

>90

nd





<20

<20

<20

nd

<20

>90

>90

nd

>90

nd

>90

50–80

50–80

50–80

50–80

50–80

50–80

50–80

>95

>95

>95

>95

>95

>95

>95

>95

20–>80

50–80

50–80

20–50

<20

50–80

50–80

50–80

50–80

>90

>90

>90

>90

>90

>95

50–80

50–80

>95

50–80

>95

>95

50–80

50–80

>80

>80

>80

>80

20–>80

<20

20–50

>80

20–50

>80

20–50

–<20

>80

<20

>90

>90

25–50

>90

>90

>80

50–90

50–90

>80

>80

50–80

>90

>80

>80

20–50

nd

>90

>80

>80

<20

20–>80



Chloramination 50–80 <20 <20 <20 50–80 <20 >80 >80 <20 <20 (Sources: Ternes and Joss, 2006; Snyder et al., 2010) B(a)p = benz(a)pyrene; CBZ = carbamazepine, DBP = disinfection by-product; DCF = diclofenac; DZP = diazepam; IBP = ibuprofen; NDMA=Nnitrosodimethylamine; nd = no data; PAC = powdered activated carbon; PCT = paracetamol. 1 erythromycin, sulfamethoxazole, triclosan, trimethoprim 2 ethynylestradiol; estrone, estradiol and estriol 3 progesterone, testosterone

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The Montebello Forebay project is a potable reuse project that meets drinking water standards for chemical constituents. The second part of this research extended into identifying safe exposure concentrations for a broad range of chemicals of interest to the recycled water community based on published toxicity information; the final task of this work included identification of contaminants that would be a concern in 5 to 20 years (WRRF, 2010c, 2011a, and 2012f). Results from this report point to the potential for a shift in the pharmaceutical industry to increase focus on research, development and production of more biodegradable pharmaceuticals. Treatment technologies for producing reclaimed water are well documented to remove trace chemical constituents to very low concentrations, resulting in very low risks to human health. However, the continuous stream of reported detection of CECs in reclaimed water has led to public concern about their presence and the implications for adopting planned potable reuse. Better public education regarding the effectiveness of the available treatment technologies and the safety of highly treated reclaimed water, as described in Chapter 6, should be a high priority for scientists and regulators. Potential Impact of Residual Trace Chemical Constituents. Most WWTPs and many water reclamation facilities are not designed for removal of TrOCs. As a result, residual antibiotics and metabolites are inadvertently released into the environment. This may lead to proliferation of antibiotic resistance (AR) in pathogenic or nonpathogenic environmental microorganisms (Pauwels and Verstraete, 2006). However, the proliferation of AR is not limited to the environment and may actually occur during therapeutic use, during which intestinal flora are exposed to high concentrations of antibiotics, or during wastewater treatment, particularly secondary biological processes (Clara et al., 2004; Dhanapal and Morse, 2009). A 2000 WHO report identified AR as a critical human health challenge for the next century and heralded the need for “a global strategy to contain resistance” (WHO, 2000). According to the report, more than two million Americans are infected each year with antibiotic-resistant pathogens, and 14,000 die as a result. A potential source of this proliferation of AR is the use, whether for human health or animal

2012 Guidelines for Water Reuse

husbandry, and subsequent release of antibiotics and metabolites into the environment. It is estimated that up to 75 percent of antibiotics are excreted unaltered or as metabolites (Bockelmann et al., 2009). And yet, few studies have attempted to identify processes contributing to the selection of AR bacteria. Such information will be critical in the development of treatment strategies to reduce the potential for AR proliferation in the environment. There are several critical locations within a typical WWTP where AR may accumulate or develop. AR genes may already be present in raw sewage entering a WWTP, but there is also considerable evolutionary pressure within a WWTP to induce such changes. Specifically, the conventional activated sludge (CAS) and MBR processes may be a significant source of AR due to their continuous exposure of bacteria in ideal growth conditions to relatively high concentrations of antibiotics. Despite the direct correlation between solids retention time (SRT) and reductions in antibiotic concentrations, higher SRT also provides prolonged exposure of bacterial populations to relatively high concentrations of antibiotics present in primary effluent (Clara et al., 2005; Gerrity et al., 2012; Salveson et al., 2012). Some MBRs will operate at SRTs on the order of 50 days, while CAS processes may be operated in the range of 1 to 20 days, which is more than sufficient to allow for bacterial adaptation given their high growth rates. In both MBR and CAS configurations, AR bacteria may accumulate in biosolids and may also be discharged to the environment in finished effluent or reclaimed water. To reduce the potential for AR proliferation, future research should target identification of the major source(s) of AR (i.e., raw sewage, biosolids, or treated effluent), determine treatment conditions that promote AR development, and characterize the persistence of AR in the environment. Ultimately, this knowledge will assist in developing mitigation strategies and alleviating environmental and public health concerns.

6.3 Regulatory Approaches to Establishing Treatment Goals for Reclaimed Water

Countless studies have provided information about the operating conditions of wastewater treatment processes; treatment efficacy; and pathogen and contaminant behavior, fate, and activity in the environment along with geological parameters

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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

necessary for developing and maintaining adequate processes to prevent contamination of groundwater and other water sources. Together, these studies established the role of each unit process in ensuring treatment efficiency. Many state guidelines and regulations emphasize the use of a multiple-barrier approach that combines several unit processes to ensure redundancy. Title 22 of the California Code of Regulations for Water Recycling Criteria (Title 22) (2009) and in Chapter 62-610 of the Florida Administrative Code for Reuse of Reclaimed Water and Land Application (2009) both require a multibarrier approach.

6.3.1 Microbial Inactivation With respect to understanding the human health impacts as a function of exposure to microbial contamination, it is useful to review historical work that was conducted and has been used as the basis for the EPA’s Recreational Water Quality Criteria (RWQC). The criteria recommendations are for the protection of people using bodies of water for recreational uses, such as swimming, bathing, surfing, or similar watercontact activities, and are based on an indicator of fecal contamination, which is a pathogen indicator. The EPA RWQC may be used by states to establish water-quality standards that can provide a basis for controlling the discharge or release of pollutants from WWTPs. In many cases, individual states have used these criteria as the basis for development of microbial standards for some reuse. Interestingly, many of the states have used the EPA RWQC as the basis for reuse.

density was about 2,300 per 100 mL (Stevenson, 1953). In 1968, the National Technical Advisory Committee (NTAC) translated the total coliform concentrations to 400 cfu/100 mL based on a ratio of total coliform to fecal coliform, and then halved that number to 200 cfu/100 mL (EPA, 1986). The NTAC criteria for recreational waters were recommended again by EPA in 1976. In the late 1970s and early 1980s, EPA conducted a series of epidemiological studies to evaluate several additional organisms as possible indicators of fecal contamination, including E. coli and enterococci; these studies showed that enterococci are a good predictor of gastrointestinal illnesses in fresh and marine recreational waters and E. coli is a good predictor in freshwater (Cabelli et al., 1982; Cabelli, 1983; Dufour, 1984). The current 2012 draft RWQC now has acknowledged the use of quantitative real time polymerase chain reaction (qPCR) data for enterococci and set levels in recreational settings. The qPCR method was found to be superior to cfu in predicting illness (Wade et al. 2008), and acceptable risk levels of 8 illnesses per 1,000 exposures have been set. Thus, at the state level this allows discussion if these approaches and levels of risk could be appropriate for the various levels of use for reclaimed water.

In December 2011, EPA released a new draft RWQC that recommended using the bacteria enterococci and E. coli as indicator organisms for freshwater. While the numeric criteria for the geometric mean of organisms are identical to the 1986 RWQC, there are also recommendations for how to address the maximum statistical values. It is unknown at this time what, if any, changes to the draft will be implemented before the new criteria are published as final.

Concurrently, several key studies were conducted that contributed significantly to understanding recycled water treatment processes, benefits of the multiplebarrier approach, and the long-term impacts of using recycled water. The Pomona Virus Study (Miele, 1977) was a landmark study that provided a database for wastewater-treatment unit process performances. The data could be used to make regulatory decisions regarding alternative treatment system variances of the California recycled water regulatory requirements (Title 22), at that time (California Administrative Code, 1978; Dryden et al., 1979; Miele, 1977). The study concluded that nearly complete virus removal is possible using additional filtration and disinfection steps and opened up the possibilities of wastewater reuse for various applications.

The historical development of the EPA RWQC began in the 1960s, when the U.S. Public Health Service recommended using fecal coliform bacteria as the indicator of primary contact with fecal indicator bacteria. Studies showed that in surface waters impacted by wastewater discharges, there was a reported, detectable health effect when total coliform

Since then, the potential health effects from long-term use of recycled water were evaluated in three epidemiological studies (Nellor et al., 1984; Sloss et al., 1996; Sloss et al., 1999). Almost 600 filtered effluent and groundwater well samples were analyzed for human viruses, and no viruses were found. Further, two additional studies were conducted to increase the

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2012 Guidelines for Water Reuse

Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

understanding of the effectiveness of SAT processes for use in designing, operating, and regulating SAT systems, which are further discussed in Section 6.4.5.3 (Fox et al., 2001; Fox et al., 2006). In these studies, culturable human viruses were found in disinfected secondary effluents and downstream monitoring wells, indicating that SAT does not completely remove these viruses. However, where coagulation and filtration processes are added to the reclaimed water treatment process, the disinfected effluent samples and water associated with groundwater spreading operations does not contain culturable human viruses. These findings reiterate that plants with different levels of treatment produce different qualities of recycled water and that properlydesigned treatment can remove viruses to below detection limits. Thus, there is a substantial body of scientific evidence that most states use in development of microbiological criteria for reuse; and most states that have reuse rules or guidelines base their criteria on the removal of indicator organisms. Generally, reuse applications in which only specific applications with minimal human contact are allowed (e.g., irrigation of fodder crops for livestock use) do not require the same level of disinfection as applications in which human contact is more likely to occur (e.g., irrigation of landscaping or turf in a public area). A majority of states that allow and permit applications specify microbiological effluent quality and do not specifically require certain treatment technologies, with several notable exceptions (e.g., California, Washington, and Hawaii). For example, North Carolina has recently produced reuse-quality specifications for two categories of reuse applications. The level of treatment required for the use with the highest potential for human contact includes criteria of 6-log (99.9999 percent) removal for E. coli, 5-log (99.999 percent) removal for coliphage, and 4-log (99.99 percent) removal for Clostridium perfringens. In California, the regulatory approach is based on treatment technology with specific performance requirements. The most stringent reclaimed water treatment uses in California include oxidation, sedimentation, coagulation, filtration, and disinfection. Taken as a whole, these treatment strategies are useful for the removal and inactivation of pathogens to undetectable or very low levels in reclaimed water.

2012 Guidelines for Water Reuse

California’s recycled water requirements were adopted from the guidelines developed for the SDWA requirements of 1974 and are currently the most protective requirements in the nation. For unrestricted public access, including edible crop irrigation and swimming, the California Title 22 requirements include specific filtration and disinfection criteria that are designed to remove and/or inactivate 5-log of viruses. The requirements also include monitoring limits for total coliform bacteria, while many states have less stringent limits based on fecal coliforms. Rigorous turbidity requirements that are a component of the California criteria are used as a surrogate measure of filtration performance, which, as described in Section 6.4.2, is an important factor in achieving the rigorous microbial inactivation requirements. Further, disinfection technologies that are approved for application in reuse projects must demonstrate the equivalent of 5-log reduction of poliovirus over a range of operating conditions. More recently in California, new draft groundwater replenishment regulations have been discussed for indirect potable reuse by planned groundwater replenishment reuse projects (GRRP) that use highly treated municipal wastewater to replenish groundwater basins designated as potable water supplies by 2013 (CDPH, 2011). Draft provisions of the GRRP regulations would be based on reducing the risk of waterborne disease and would include pathogen controls requiring treatment systems to achieve 12-log virus reductions and 10-log reductions of the protozoan parasites Cryptosporidium oocysts and Giardia cysts through at least three treatment barriers. Up to 6-log removal credit would be allowed for surface and groundwater storage that is at least 6 months in duration. Treatment facilities that employ approved filtration and disinfection processes or an approved AOP process with at least 6 months of underground retention prior to use can obtain a 10-log removal credit for Cryptosporidium oocysts and Giardia cysts. Use of proven, CDPH accepted technology/treatment processes reduces the burden on utilities to pilot proven processes and to prove reduction of microbial contaminants through underground storage.

6.3.2 Constituents of Emerging Concern The majority of wastewater-derived trace chemical constituents are not specifically regulated in the United States, although pretreatment requirements and

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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

effluent guidelines and secondary and advanced treatment are beneficial for reducing loadings of many chemicals. Moreover, with thousands of chemicals potentially present in reclaimed water, compiling a comprehensive list of chemicals that could be present in trace concentrations is not feasible. In fact, EPA considered a select number of trace chemical constituents on their most recent Candidate Contaminant List (CCL3) and the proposed Unregulated Contaminants Monitoring Rule 3 (UCMR3) for drinking water. In the absence of federal mandates, individual states may choose to regulate individual chemical constituents. The WHO concluded that WHO guidelines were not necessary for pharmaceuticals in water supplies, and it did not recommend general monitoring of water supplies for pharmaceuticals (WHO, 2011). Extensive regulations for trace chemical constituents in recycled water for potable applications and drinking water are probably neither feasible nor necessary. Treatment specifications or guidelines for particular end uses, such is the approach for all U.S. drinking water supplies, may be useful. However, benchmarks for water quality composition are useful for decisionmakers as well as public confidence. Development of benchmarks for specific chemicals, especially pharmaceuticals and pesticides, is feasible because they usually have very extensive databases developed as part of their registration or approval process, and margins of exposures are available relative to therapeutic or toxic doses (Bull, et al., 2011). Screening techniques, such as estimation of Thresholds of Toxicological Concern, are also available for use in prioritizing and reducing long lists of chemicals to those of potential greater interest (Cotruvo, 2011). These techniques could be applied rapidly and at relatively low cost. Another useful model for producing benchmarks for unregulated water contaminants would be like the nonregulatory EPA Drinking Water Health Advisories that were initiated more than 20 years ago (EPA, 2012; Cotruvo, 2012). While there are no specific regulations for CECs in reclaimed water as of 2012, further investigation is necessary before any final decisions can be made on the subject. While the application of reclaimed water for urban and landscape irrigation (i.e., lawns, golf courses, parks, non-food gardens, etc.) is thought to pose very low risk to humans in contact with the various plants/surfaces irrigated, recent research by

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Knapp et al. (2010) indicates that there may be indirect health effects resulting from use of reclaimed water in agricultural applications . In that study, changes in antibiotic resistance in soil bacteria in samples taken and archived in the Netherlands between 1940 (when antibiotic use was beginning to be widespread) until 2008 showed supported growing evidence that resistance to antibiotics is increasing both in benign and pathogenic bacteria, which could pose an emerging threat to public and environmental health (Knapp et al., 2010). In order to understand these broader, indirect effects of CECs, one of the stated areas of priority for the USDA Agriculture and Food Research Initiative (AFRI) Program is to investigate the potential and relevance of bioaccumulation of CECs when recycled water is applied at typical irrigation rates. The USDA-AFRI is funding work to examine the potential for bioaccumulation of PPCPs by crops under irrigation with reclaimed water. This work is being conducted to help address the concerns over potential health risks posed by consuming raw food crops that may bioaccumulate these chemicals (Wu et al., 2010).

6.3.2.1 Example of California’s Regulatory Approach to CECs Over the years, the CDPH has developed a series of incremental draft criteria for the use of reclaimed municipal wastewater to recharge groundwater basins that are sources of domestic water supply (CDPH, 2008). These criteria were designed to ensure that groundwater supplies are augmented with reclaimed water that meets all drinking water standards, and other requirements. In 2009, California’s SWRCB adopted a new Recycled Water Policy that created a “blue ribbon” panel to guide future state actions relative to CECs by conducting a review of scientific literature related to use of reclaimed water and current knowledge on risks that might be posed by CECs and to make recommendations regarding monitoring for CECs (SWRCB, 2009). Background on the California Recycled Water Policy and CECs, including links to public hearings and reports, is available online (SWRCB, 2011). The Advisory Panel report Monitoring Strategies for Chemicals of Emerging Concern (CECs) in Recycled Water – Recommendations of a Scientific Advisory Panel was issued in June 2010 (Anderson et al., 2010).

2012 Guidelines for Water Reuse

Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

The panel provided a conceptual framework for assessing potential CEC targets for monitoring and used the framework to identify a list of chemicals that should be monitored currently (Anderson et al., 2010). The panel also recommended that the prioritization process be reapplied on at least a triennial basis and that the state establish an independent review panel to periodically review CEC monitoring efforts. The CECs the panel recommended for monitoring currently are those found in recycled water at concentrations with human health relevance, as defined by the exposure screening approach recommended by the panel. Further, the panel recommends monitoring both the performance of treatment processes to remove CECs using selected “performance indicator CECs,” and surrogate/operational parameters to verify that treatment units are working as designed. Surrogates include turbidity, DOC, and conductivity. Health-based CECs selected for monitoring included caffeine, 17βestradiol, NDMA, and triclosan. Performance-based indicator CECs were selected by the panel, each representing a group of CECs: caffeine, gemfibrozil, n,n-diethyl-meta-toluamide (DEET), iopromide, NDMA, and sucralose. Caffeine and NDMA serve as both health and performance-based indicator CECs. CDPH provided recommendations to the SWRCB specific to CECs and the CDPH monitoring requirements for surface spreading groundwater recharge projects (CDPH, 2010). CDPH recommendations were specific for chemicals on the current CDPH notification-level list, other chemicals, and chemicals specific to a new permit. CDPH notification-list chemicals to be monitored are boron; chlorate; 1,4- dioxane; nitrosamines (NDMA, NDEA, and NDPA); 1,2,3-trichloropropane; naphthalene; and vanadium, with initial quarterly testing that could be reduced to annual testing if the chemicals are not detected. Initial quarterly monitoring was also recommended for chromium-6, diazinon, and nitrosamines NPYR and N-Nitrosodiphylamine, with the ability to reduce to annual testing if the chemical is not detected. Three additional chemicals, bisphenol A, carbamazepine, and TCEP, were recommended for annual monitoring. CDPH also included a statement that it would consider source waters and treatment process when recommending project-specific monitoring requirements, such as monitoring for formaldehyde when an AOP process is used.

2012 Guidelines for Water Reuse

The most current draft regulations, issued in November 2011, are scheduled to be finalized in 2013 (CDPH, 2011). Other scientific oversight groups required by legislation for individual projects have recommended other performance-monitoring regimens to demonstrate the effectiveness of the treatment trains being employed. Very few chemicals are being detected, even at ppt levels, in fully-treated waters.

6.3.2.2 Example of Australia’s Regulatory Approach to Pharmaceuticals In 2008, Australia was the first country to develop national guidelines for potable reuse with the release of Phase 2 of the Australian Guidelines for Water Recycling (AGWR): Augmentation of Drinking Water Supplies (EPHC, 2008). The AGWR provide a risk management framework, rather than simply relying on end-product (reclaimed-water) quality testing as the basis for managing water recycling schemes. They include concentration-based numeric guidelines for at least 86 pharmaceuticals in reclaimed water. The guideline concentrations are based on application of a safety factor of 1,000 to 10,000 relative to a single therapeutic dose. These are not mandatory and have no formal legal status, but they were provided as nationally consistent guidance for those recycling projects. In general, the guideline concentrations are far higher than concentrations found in drinking water or reclaimed water. While there is no definitive risk assessment tool for some types of trace chemical constituents in recycled water, the Australian guidelines do provide a methodology for evaluating the potential risk from known and emerging chemical constituents (NHMRCNRMMC, 2004; EPHC, 2008; and Snyder et al., 2010).

6.4 Wastewater Treatment for Reuse

The level of wastewater treatment required for any project depends on the end use or discharge location, but in the United States, all wastewater is required to be treated to secondary levels, at a minimum. Secondary treatment is designed to achieve removal of degradable organic matter and suspended solids. Filtration and disinfection provide additional removal of pathogens and nutrients, and AOPs can target trace chemical constituents. Wastewater treatment from raw to secondary is well understood and covered in great detail in other publications, such as the WEF Manual of Practice (MOP) 8, Design of Municipal Wastewater Treatment Plants (WEF, 2010). The discussion here is

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limited to treatment processes with a particular application to water reuse and reclamation, which also includes source control. For many uses of reclaimed water, appropriate water quality can be achieved through conventional, widelypracticed secondary, filtration and disinfection processes. However, as the potential for human contact increases, advanced treatment beyond secondary treatment may be required. As discussed in Section 1.5, the level of treatment and treatment processes to be employed for a reuse project should consider the end use to establish water quality goals and treatment objectives. Not all constituents have negative impacts for all uses. Nutrients, for example, can be beneficial when water is reused for agricultural irrigation, offsetting the need for supplementally applied fertilizers, and in these cases nutrient removal in treatment may not be helpful. On the other hand, where water is reused for environmental flows, nutrient removal could be critical to avoid overloading aquatic ecosystems with these nutrients. Likewise, nutrient removal would be targeted where reclaimed water would impact future drinking water sources, such as groundwater, as excess nutrients can be harmful to human health. A summary of the level of treatment required for specific reclaimed-water end uses in 10 states is provided in Section 4.5.2. Three processes have seen significant technology advances since publication of the 2004 guidelines: filtration, disinfection, and advanced oxidation. The purpose of this section is to describe these processes and some of the recent technology advances, as well as highlight the increasingly important role of natural treatment systems, such as wetlands and SAT systems, for polishing or further treating the reclaimed water.

6.4.1 Source Control A critical component of any water reuse program is to develop and implement an effective industrial source control program as the first barrier to preventing undesirable chemicals or concentrations of chemicals from entering the system. The pollutants in industrial wastewater may compromise municipal treatment processes or contaminate the treated effluent by passthrough. To protect municipal treatment plants and the environment, the CWA established the National Pretreatment Program, which requires industrial dischargers to use treatment and management

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practices to reduce or eliminate the discharge of harmful pollutants to sanitary sewers. The term “pretreatment” refers to the requirement that nondomestic sources discharging to publicly-owned treatment works control their discharges. EPA has established technology-based numeric effluent guidelines for 56 categories of industry, and the CWA requires EPA to annually review its effluent guidelines and pretreatment standards and to identify potential new categories for pretreatment standards; recommendations are presented in a Preliminary Effluent Guidelines Program Plan. The 2010 Plan included a strategy for the development of BMPs for unused pharmaceutical disposal at hospitals and other healthcare facilities that is intended to eliminate inconsistency in messages and policies regarding flushing of drugs to municipal sewer systems. Wastewater management agencies are required to establish local limits for industries as needed to comply with NPDES permits and to prevent discharges into sewerage systems that inhibit or disrupt treatment processes, or the uses/disposal of treated wastewater. Generally, pollution prevention programs will be effective if certain conditions can be met: 

The pollutant can be found at measurable levels in the influent and collection system.



A single source or group of similar sources accounting for most of the influent loading can be identified.



The sources are within the jurisdiction of the agency to control (or significant outside support/resources are available).

Industrial sources are most easily controlled because industries are regulated and required to meet seweruse permit requirements. If a pollutant source is a commercial product, such as mercury thermometers or lindane head lice remedies, it may not be within the local agency’s power to ban or restrict the use of the product; in such cases, to be effective, restrictions on product use must be enforced on a regional, statewide, or national basis, such as the ban on nonylphenol (a surfactant ingredient with endocrine disrupting properties) use in the European Union. For agencies implementing IPR projects, source control programs may go beyond the minimum federal requirements. Many agencies have developed local or

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statewide “no drugs down the drain programs” and/or drug take-back programs. For example in Texas, SAWS has developed a collection program for unused medications. Other agencies have included additional program elements to enhance their pollution prevention efforts; the OCSD, which provides reclaimed water to the OCWD for the Groundwater Replenishment System Project in southern California, has instituted additional program elements that build on the agency’s traditional source control program. These elements include a pollutant prioritization scheme that includes chemical fate assessment for a broad range of chemicals; an outreach program for industries, businesses, and the public; and a toxics inventory that integrates a geographical information system and chemical fact sheets. The OCSD successfully used its source control program to reduce the discharge of NDMA and 1,4-dioxane from industries into its wastewater management system. Oregon has passed rules that set trigger levels for pollutants, requiring municipal wastewater facilities to develop toxics reduction plans for listed priority persistent pollutants if any of the pollutants are found in their effluent above the trigger levels set by the rule (Oregon DEQ, n.d.). The rule includes numeric effluent concentration values for 118 priority persistent pollutants for which drinking water MCLs have not been adopted, but that the Oregon Environmental Quality Commission has determined should be included in a permitted facility’s toxic-pollutant reduction plan. The list includes pollutants that persist in the environment, and pollutants that accumulate in animals. All of the pollutants on the list have the potential to cause harm to human health or aquatic life; some are known carcinogens and others are believed to disrupt endocrine functions. The list includes both well-studied pollutants that people have worked to reduce for many years and others for which little information exists. Results of wastewater effluent monitoring will be compared against trigger levels, and where effluent concentrations exceed the trigger level, the facility will be required to develop a toxics reduction plan aimed at reducing levels of that pollutant in its discharge. The Oregon DEQ consulted with a Science Peer Review Panel to develop the list of pollutants and triggers.

6.4.2 Filtration Filtration removes particulates, suspended solids, and some dissolved constituents, depending on the filter

2012 Guidelines for Water Reuse

type. In addition, by removing particles remaining after secondary treatment, filtration can result in a more efficient disinfection process. While chemical or biophysical disinfection processes inactivate or destroy many classes of microorganisms, pathogens removed by filtration are removed by physical adsorption or entrapment. The ability of filtration to help reduce pathogens is a function of the pore size of the media, the size of the pathogen, and the impact of chemical addition, if used. Most types of filtration are able to remove some of the largest pathogens, such as protozoan cysts. Smaller pathogens, including bacteria or viruses, can be removed in filtration either through size exclusion by filters with very small pore sizes, or by filtering out larger particles to which the smaller pathogens are adsorbed. Because a large proportion of pathogens in treated wastewater prior to disinfection tend to be associated with particles, many states with reuse regulations also include requirements for removal of particles. The rationale of these requirements is that effective filtration, and thus particle removal, is part of a multiple-barrier treatment process. A second benefit is improvement in disinfection efficiency with fewer particles, lower turbidity, and higher transmittance. Regulatory factors can affect the design of filtration, where required, for water reuse activities. For example, the regulatory requirements for water reuse filtration in California and Florida (the two states where the most water reuse occurs) are worth comparing. Florida does not stipulate the type of approved filters or loading rate to the filter as long as water quality requirements for TSS are satisfied. On the other hand, in California, the filtration technology must be conditionally accepted by the CDPH prior to its application for treatment of recycled water, in addition to meeting strict turbidity limits during performance. Many types of filtration, including depth filtration, surface filtration, and membrane filtration, have received approval from CDPH; the loading rate at which the conditionally-accepted filter can be operated is also specified. Both states require chemical feed facilities to improve filtration by first coagulating particles, but the chemical feed facilities can remain idle if the TSS or turbidity limits are satisfied. In California, several conventional filtration 2 technologies are approved for operation at 2 gpm/ft 2 (traveling bridge filters) and 5 gpm/ft (mono-, dual-, or mixed-media filters), and disinfection with chlorine gas

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or sodium hypochlorite is allowed under stipulated conditions. All other filtration and disinfection technologies must undergo rigorous third-party testing and receive “conditional acceptance” from the CDPH prior to use. For filtration testing, this includes longterm performance demonstration for meeting turbidity criteria and other objectives. In recent years, with increased emphasis on improving treatment for reuse, there have been many innovations in filtration, and today there are numerous types of commercially-available filtration technologies. Therefore, a brief discussion of recent advances in filtration technology as it relates to treatment of reclaimed water is merited. Regardless of the significant variations in configurations and characteristics of the filters, there are three types of commercially-available filtration technologies: depth filtration, surface filtration, and membrane filtration.

6.4.2.1 Depth Filtration Depth filters have the longest history of use at WWTPs. Depth filters consist of a bed of noncompressible or compressible media. Noncompressible media, such as sand, anthracite, or garnet, is most commonly used. Depending on the type of filter (i.e., mono-, dual-, or mixed-media), the effective size of the media in noncompressible media filters varies between 0.0016 and 0.08 in (0.4 and 2.0 mm) in average diameter. Noncompressible media filters contain columns packed with several feet of media, and, depending on the filter configuration, utilize a continuous, semi-continuous, or batch backwash process. Utilities with existing depth filtration plants are also increasing their existing filtration capacity by conducting filtration studies to document the ability of their filters to operate at higher hydraulic loading rates. These advances in loading rates allow for substantial reduction in filtration costs. In 2000, depth filters with synthetic compressible media became commercially available. These compressible-media filters utilize a synthetic medium that has a diameter of approximately 1.25 in (32 mm). During normal filtration, media in the compressiblemedia filters is compressed 15 to 40 percent, and filtration occurs. Backwashing occurs in a batch process, during which the media is uncompressed and then cleaned with an air scour and a hydraulic wash. The high porosity of the compressible media (around 88 percent) allows for higher hydraulic loading rates

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than other depth filter, while the backwashing continuously recharges the media surface to prepare it for another round of filtration so that filtration efficiency is not compromised. Conditional acceptance of this technology for water reuse applications was granted in 2003 by CDPH for hydraulic loading rates up to 30 2 2 gpm/ft (1200 L/min/m ), which is more than six times the approved filtration rate of conventional depth filters. More recent advances in this technology have resulted in the development of a modified compressible media that operates at even higher hydraulic loading rates (Caliskaner et al., 2011).

6.4.2.2 Surface Filtration The main difference between surface and depth filters is the depth of the packed media and the media material. Depth filtration typically includes several feet of packed media, while surface filters are generally a fraction of a millimeter to several millimeters thick. Surface filters typically consist of screens or fabric manufactured from nylon, polyester, acrylic, and stainless steel fibers. Most surface filters are gravity fed, and backwashing is semi-continuous; however, for short periods of time it may be necessary to perform backwash in a continuous mode. Manufacturers of disk filters, which are a type of surface filter with the filtration screen mounted on a series of disks, have made recent improvements in performance and efficiency; increasing numbers of disk filter configurations are gaining regulatory approval in California, where filter technologies must be approved. In 2001, the CDPH approved the first disk filtration technology for water reuse applications at 2 2 hydraulic loading rates up to 6 gpm/ft (230 L/min/m ), and other disk filtration configurations have more recently received conditional acceptance at the same loading rate. A high-rate disk filter was granted conditional acceptance for loading rates up to 16 2 2 gpm/ft (620 L/min/m ), in 2009 (State of California, 2009). At least one manufacturer has received CDPH approval for a submerged, fixed cloth media, and there are several others that have applied for acceptance.

6.4.2.3 Membrane Filtration A membrane may be defined as a thin film separating two phases and acting as a selective barrier to the transport of matter; detailed discussion of membrane filtration processes are provided in EPA’s Membrane Filtration Guidance Manual (EPA, 2005). For water to flow through a membrane there must be some type of

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secondary effluent using a continuous backwash sand filtration system in parallel with a 0.2 nominal pore size MF system for comparison of filtration efficiency [USCA-San Ramon]. Studies conducted on this reuse system show that a higher level of particle rejection (which was achieved with the MF system) correlates with higher microorganism rejection (Cryptosporidium, Giardia, and total coliforms), and that the filtration system can be an important part of a multi-barrier approach to reclaimed water treatment (WRRF, 2012a). It is important to note that neither filtration system in this case study example was able to provide virus rejection. While smaller pore size membranes, such as UF, NF, and RO systems, can achieve virus removal when membranes do not have any flaws, chemical disinfection is needed for virus removal, which is why the multi-barrier approach is needed.

driving force, and for reuse applications, membrane processes are typically pressure-driven processes. Some novel desalination approaches, which may gain application in reclamation of brackish waters, use osmotic gradients as the driving force. A summary of the driving force and nominal pore size is provided in Table 6-6 for major, commercially-available filtration processes. There are significant differences in the pore sizes of various filter types available (Table 6-6). The use of filters from the membrane group will result in a higher filter effluent quality than can be achieved by using either surface or depth filters. This higher effluent water quality with MF or UF membranes comes at a higher cost of 1.5 to 2 times that of depth or surface filtration systems because of energy and equipment costs. NF and RO costs are substantially higher, due to high energy costs and specialized equipment.

6.4.2.4 Biofiltration Biological filtration or biofiltration is a treatment technique in which a granular media filter is allowed to be biologically active for the purpose of removing biodegradable constituents such as TOC. Most any granular media filter is capable of supporting microbial growth, assuming that the water being filtered does not have a disinfectant residual. As a result, the biological activity can improve treatment performance beyond particle removal such that water quality is improved with respect to a wide range of dissolved organic

The capacity of a filtration system is usually evaluated based on filtration rate and the available surface area in the filtration system. Manufacturers are constantly developing new filtration technologies or modifying their established technologies to improve filter performance by increasing the hydraulic loading rates or increasing water quality, thus making their filters more economical or providing better value. In San Ramon, Calif., the DSRSD provides filtration of 1

Table 6-6 Summary of filter type characteristics Filter Type

Filtration Driving Force

Nominal Pore Size, um Depth

Non-Compressible Media

Gravity or pressure differential

Compressible Media Surface Filtration

60-300

Surface Filtration Gravity

5-20 Membrane

2

Contaminants targeted for removal TSS, turbidity, some protozoan oocysts and cysts

TSS, turbidity, some protozoan oocysts and cysts

TSS, turbidity, some protozoan oocysts and cysts, some bacteria and viruses Macromolecules, colloids, most Ultrafiltration Pressure differential 0.002-0.050 bacteria, some viruses, proteins Small molecules, some Nanofiltration Pressure differential <0.002 hardness, viruses Very small molecules, color, Reverse Osmosis Pressure differential <0.002 hardness, sulfates, nitrate, sodium, other ions 1 Information taken from California Department of Public Health (2012), Metcalf & Eddy (2003) 2 Information from Water Treatment Membrane Processes (AWWA, 1996) Microfiltration

Pressure differential

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0.05

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contaminants, including pesticides, EDCs, and pharmaceuticals, although the degree to which biological activity contributes to treatment performance varies (Bonne et al., 2006; Wunder et al., 2008; Van der Aa et al., 2003). Several types of biofiltration can be used, including slow sand, rapid-rate, and granular activated carbon (GAC) (Evans, 2010). Depending on the pore size of the filter media, substantial removal of trace chemical compounds can be obtained. The mechanisms of physical removal include removal of particles with sorbed chemicals, removal of chemicals by sorption into media pores, or electrostatic repulsion (WRRF, 2012a; Kimura et al., 2003). Biofiltration, which is commonly used in potable reuse schemes, enhances the use of common physical and chemical means to remove contaminants through biodegradation. With increasing interest in obtaining higher quality reclaimed water, biofiltration, as part of a multi-barrier treatment process, could replace higher energy processes such as RO in certain applications (see sections 3.1 and 3.7 for the Namibia model for potable reuse). Slow Sand Filtration. Slow sand filtration, along with natural filtration processes, such as SAT and riverbank filtration, which are discussed in Section 6.4.5, is actually one of the oldest drinking water treatment processes still being used today. Slow sand filtration uses small-diameter sand with low surface-loading rates without chemical coagulation. In slow sand biofiltration, the sand’s top surface becomes coated with a biologically active layer called a schmutzdecke, which is periodically scraped off or harrowed to renew a system’s hydraulic capacity. Although slow sand filtration primarily uses both physical and biological mechanisms to remove contaminants, the biological mechanism dominates. Rapid-Rate Filtration. Rapid-rate filtration uses larger-diameter media, such as sand and anthracite, and surface loading rates about 100 times higher than slow sand filtration. A coagulant, such as ferric chloride or alum, is added upstream of the process to remove turbidity and organic matter. The filter must be backwashed periodically with chlorinated or nonchlorinated water. A preoxidation process that uses ozone, chlorine, chlorine dioxide, or permanganate is sometimes used, which can enhance biological activity by oxidizing complex organic matter

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into smaller, more biodegradable organic compounds that are readily removed by a rapid-rate filter. GAC Filtration. When compared with sand or anthracite media, GAC has the additional property of adsorption and can accumulate greater microbial biomass (or biofilm) on activated carbon media. Biomass plays an important role in biodegrading contaminants and supplementing GAC filtration. GAC lifetime—the time between media replacements—can be extended by biological processes. Therefore, GAC filtration uses physical and biological processes for contaminant removal. Depending on contact time requirements to remove target contaminants, GAC filtration can be designed as a GAC rapid-rate filter, a mono-media deep-bed contactor, or a filter cap on top of a sand or anthracite filter bed. As with conventional rapid-rate filters, upstream coagulants and oxidants frequently are used to improve contaminant removal. Additionally, GAC’s adsorptive properties aids in producing the desired filtered water quality through adsorption; thus, GAC must be regenerated periodically, particularly where adsorption may play a more dominant treatment role than the biological mechanism of contaminant removal.

6.4.3 Disinfection Relative removal of microbial indicators and pathogens by various treatment stages is included in Table 6-3; however, in order to provide reclaimed water that meets the intended use, disinfection using one or more of these technologies is an important part of any reuse scheme. Disinfection is designed to inactivate microorganisms, including viruses, bacteria, protozoan oocysts and cysts, and helminthes; these pathogenic organisms and the associated health risks were discussed in Section 6.2.1. The most common reclaimed water disinfection method in use to date is chlorination. UV disinfection is a well-proven and commonly-used alternative to chlorine. Other disinfection alternatives are peracetic acid (PAA), ozone, pasteurization, and ferrate (WERF, 2008); PAA is not discussed further because no municipal reuse applications have been implemented in the United States, to date. To date, California is the only state that has technology-based regulations for disinfection, although Florida references the NWRI UV Guidelines in its regulatory code as guidance for permitting reuse applications (NWRI, 2003). Thus, while there are many

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disinfection technologies that show promise for reuse applications, this section covers those technologies that have demonstrated pathogen reduction through rigorous research and have obtained “conditional acceptance” from the CDPH for use on reclaimed water treatment, with the exception of ferrate, which is also included. There are four technologies accepted by the CDPH: chlorination, UV disinfection, ozone, and pasteurization. Dose requirements for these disinfection technologies under California Title 22 are provided in Table 6-7, along with comparative dose requirements for reuse in Florida under FAC 62-610.

6.4.3.1 Chlorination Chlorine disinfection may be accomplished using free chlorine or chloramines. Regardless of the mode of chlorination, the efficiency of chlorine disinfection depends on the water temperature, pH, degree of mixing, time of contact, presence of interfering substances, concentration and form of chlorinating species, and nature and concentration of the organisms to be destroyed. In general, bacteria are less resistant to chlorine than viruses, which, in turn, are less resistant than parasite ova and cysts. Disinfection requirements often include monitoring of total chlorine (which includes free chlorine, chloramines, and other chlorine/organic compounds) remaining in the treated water after a certain contact time. When ammonia is present in wastewater, it will combine with free chlorine to form chloramines (typically monochloramine), which is less effective as a disinfectant than free chlorine and requires a disinfectant dose an order of magnitude or more than

free chlorine (WEF, 2010). Additionally, chlorine reacts with other organic constituents that remain in treated wastewater to form compounds that provide a measurable combined chlorine residual, but with a potentially low disinfection capability. The occurrence and effects of this phenomenon have been well documented (Black and Veatch, 2010; Szerwinski, et al., 2012). Chlorine disinfection efficacy is typically measured as CrT, which is the product of the total chlorine residual times the contact time. Methods of calculating CrT can vary. The CDPH, for example, specifies the CrT concept, with Cr being the total combined residual and T being the contact time at the point of measurement. CrT can also be defined as the integration of the residual concentration of the disinfectant concentration CrT over the measured contact time T. Depending on water quality and chemistry, there may be a significant chlorine demand that yields a difference in the applied and residual concentration at the required or recommended contact time. Because of the complications in wastewater, the chlorine CrT values required for various rates of inactivation must be determined empirically. Many studies have shown that a CrT for free chlorine outperforms the same CrT for chloramines; however, the assumption that a lower dose may be required for disinfection using free chlorine is misleading, because achieving free chlorine residual in wastewater effluents can be challenging for the reasons given above. Planners and designers are cautioned to confirm the currently-accepted calculation approach for any specific project.

Table 6-7 California and Florida disinfection treatment-based standards for tertiary recycled water and highlevel disinfection Disinfection Process

California 1

Florida

2

25 mg-min/L for fecal coliform <1,000 MPN/100 mL 40 mg-min/L for fecal coliform 1,000 to <10,000 MPN/100mL 120 mg-min/L for fecal coliform >10,000 MPN/100mL

Chlorination

450 mg-min/L CrT

UV

100 mJ/cm following sand or cloth 2 filtration; 80 mJ/cm following MF or UF; 50 mJ/cm2 following RO

Ozone

1 mg-min/L CT

No standard

Pasteurization

10 second contact time at 179 degrees F

No standard

2

1

No uniform standard

1

CT is the multiplication of a measured modal contact time and oxidant residual at the end of the contact period. CrT is the product of the total chlorine residual times the contact time. 2 Florida’s sliding disinfection standards for chlorination assume a direct correlation between fecal coliform concentrations and pathogen levels. Lower fecal coliform counts thus require less disinfection. 2012 Guidelines for Water Reuse

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Free and combined chlorine have measurable differences in disinfection ability. Free chlorine is a rapid and effective viral disinfectant in wastewater, but a moderate concentration of ammonia results in a combined residual with reduced disinfection potential for poliovirus and MS2 coliphage (MS2) (Cooper, 2000). In California, for example, the CrT of 450 mgmin/L is required for nonpotable water reuse applications with potential for direct public contact. At this dose, the CDPH assumes that disinfection will provide 4-log virus reduction for chlorine or chloramines. However, recent research has shown that in a high-quality nitrified effluent, a CrT value of 50 mg-min/L or lower can meet the stringent “tertiary recycled water” disinfection quality for reuse in California (Maguin et. al., 2009). Pathogenic protozoan parasites, such as Giardia lamblia and Cryptosporidium parvum and hominis, are found in the environment as cysts or oocysts, which protect them from environmental insults and inactivation by oxidants such as chlorine (EPA, 2004). In light of recent protozoan treatment goals, research, and publications, concerns over the use of chlorine for reclaimed water disinfection have been raised (Gennaccaro et al., 2003; Garcia et al., 2002). Gennaccaro et al. (2003) found infectious Cryptosporidium oocysts in 40 percent of final disinfected effluent samples in a survey of several reclamation facilities that used filtration and chlorination. Thus, Giardia and Cryptosporidium (some viable) have been documented in the literature to be found in reclaimed water effluents, the majority of which utilized chlorination. Some viable protozoan pathogens in reclaimed water disinfected with chlorine should be anticipated. Because of the challenges of Giardia and Cryptosporidium inactivation, combining chlorine disinfectants with UV has recently attracted increasing attention, because of benefits such as disinfection of a wider range of pathogens, improved reliability through redundancy, reduced DBPs, and potential cost savings. A recent report showed that when chloramines were combined with UV, median total coliform levels below 2 cfu/100 mL and 5-log poliovirus inactivation can be achieved; however, free chlorine is still a more effective disinfectant than chloramines (WRRF, 2010d).

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EPA specifies that in drinking water treatment engineers should only anticipate significant Giardia inactivation with free chlorine (3-log inactivation at a CrT of 50 mg-min/L, depending on temperature and pH), as combined chlorine requires a CrT of 1,000 mgmin/L for an equivalent level of treatment. For those states that dictate a required chlorine CrT, regulatory compliance includes continuous monitoring and control of CrT in conjunction with maintaining microbiological targets. Some states, such as California, require demonstration of minimum contact times upon completion of new chlorination facilities. And, for reclaimed water entering a reclaimed water distribution system, it is common to increase the chlorine residual based on time of travel and residual demand. If reclaimed water is released to a stream for flow augmentation and dechlorination is required, dechlorination can be provided as an end-of-pipe treatment.

6.4.3.2 Ultraviolet Disinfection UV disinfection of reclaimed water is gaining in use due to increasingly energy-efficient and lower-cost UV technologies. Large systems are now successfully operating in cities such as Roseville, Calif. (45 mgd; 1,972 L/s), and Mesa/Gilbert, Ariz. (32 mgd; 1,402 L/s) [US-AZ-Gilbert]. As of 2012, UV is a well-proven and robust disinfection method; however, disinfection of treated wastewater by UV can be complicated by several factors. Most of these factors are governed by the level of treatment the utility has implemented prior to the UV disinfection reactor. Two key water quality issues that can impact UV disinfection performance and efficiency are the presence of particle-associated microorganisms and the UV transmittance (UVT) of the wastewater. Particles can shade target microbes, shielding them from UV light; bacteria frequently become embedded in particulate matter, partially or wholly protecting them from the UV light (Paraskeva et al., 2002; Emerick et al., 1999). Particle size distribution may indicate the potential for UV disinfection efficiency, with smaller particles having less effect on UV efficiency than larger particles, as the shielding effect is reduced (Jolis et al., 2001); particles larger than 10 microns in size can shield microorganisms from disinfection by UV light. UV disinfection is enhanced by filtering water prior to disinfection, both by the reduction in particulates (a reduction in the number of large particles with embedded and shielded microorganisms) and by the

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increase in UVT (a reduction in smaller particulates that do not shield organisms but do reduce UVT and thus reduce UV efficiency). Chevrefils et al. (2006) provide a thorough review of the literature on bacteria, virus, and protozoa disinfection with UV and clearly shows that UV is a powerful disinfectant for most microorganisms, including viruses such as poliovirus, calicivirus, reovirus, coxsackievirus, rotavirus, and hepatitis. Typically, UV systems are designed to meet regulations for bacterial indicator organisms; thus, total and/or fecal coliform bacteria are the primary regulatory targets. For instance, California’s regulated total coliform level for “tertiary recycled water” reuse is 2.2 cfu per 100 mL of water (cfu/100 mL), which can be obtained at a relatively low UV doses (~35 to ~75 2 mJ/cm ), but higher doses are required to meet the 52 log virus requirement (100 mJ/cm ) (NWRI, 2003). UV 2 dose is measured in millijoules seconds per cm 2 (mJ/cm ) and is calculated by multiplying the UV 2 intensity measured in mW/cm and the exposure time in seconds. One challenge with UV disinfection is the possibility that some organisms may undergo photoreactivation after UV exposure; this can occur when the microorganisms repair their DNA damaged by the UV light. Photoreactivation of disinfected organisms can occur when UV-damaged cells are exposed to light in the visible wavelength spectrum (310 to 480 nm) that prompts cell-initiated repair of damaged DNA (Harris et al., 1987; Ni et al., 2002). Photoreactivation can be a function of UV dose, the concentration of organisms, UV transmittance, and suspended solids concentration. But, Lindenauer and Darby (1994) found that photoreactivation of total coliforms in UV disinfected wastewater decreased with increasing UV dose. Thus, where treated water is stored in uncovered basins, the use of moderately higher UV dose values, such as the values required in California 2 for “tertiary recycled water” (100, 80 or 50 mJ/cm depending upon filtration technology) could be employed. The UV industry has experienced substantial advances since implementation of the original systems that consisted of vast quantities of low pressure (LP), low intensity lamps, which had reasonable energy efficiency but maintenance challenges due to the large number of lamps that need to be replaced regularly.

2012 Guidelines for Water Reuse

Medium pressure (MP) UV systems solved the problem of numerous lamps but resulted in three to four times the energy use of LP systems. The UV industry responded again by developing LP, high output (LPHO) UV systems, ranging in watts/lamp from 160 watts all the way to 1,000 watts of energy to individual lamps. One of the more innovative UV technologies to reach the mainstream marketplace is microwave UV systems, which utilize microwaves to generate UV light instead of the conventional voltage differential from electrode lamps. These innovations in LPHO and microwave technologies allow for lowercost UV installation at reasonable energy use values. It is not uncommon for UV systems to have lower construction and operational costs compared to the costs for sodium hypochlorite. For those states where UV dose is regulated (e.g., California, Washington, Hawaii), UV systems must be either pre-validated or undergo on-site validation after construction. The validation process consists of detailed third-party research of individual UV reactors over the range of potential operating conditions. For UV equipment that is to be used for reuse applications in California, validation must adhere to the requirements in Title 22 to receive conditional approval from the CDPH. The CDPH requires detailed testing and operation in accordance with the National Water Research Institute’s (NWRI) Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse (NWRI UV Guidelines). The NWRI UV guidelines apply specifically to the disinfection of wastewater meeting the definition of “filtered wastewater” in California’s Water Recycling Criteria (WRC), Title 22, Division 4, Chapter 3, of the California Code of Regulations. The NWRI UV Guidelines present guidance such that after disinfection, the disinfected filtered reclaimed water is essentially pathogen free, meeting the requirement of 5-log poliovirus inactivation and a 7-day median total coliform of 2.2 MPN/100 mL. Additionally, the NWRI UV guidelines were recently revised and its publication was announced in August 2012, during final preparation of this document. The key revisions with respect to reclaimed water incorporated into the 2012 version include (NWRI, 2012):

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All reclamation systems must undergo commissioning tests that demonstrate disinfection performance is consistent with design intent.



Velocity profiles have been eliminated as an option for transferring pilot data to full-scale facility design.



On-site MS-2 based viral assays are used for both the validation and commissioning test.



A standard MS-2 dose-response curve is used to derive the reduction equivalent dose.



The design equation is based on the lower 75percent prediction interval for reclamation systems.



Commissioning tests will require seven out of eight on-site measurements exceeding the operational design equation.



Addition of an appendix to illustrate the computations involved in the application and evaluation of UV disinfection systems.

It is important to note that the NWRI UV Guidelines are applicable for specific reuse types, and there are other guidance documents available for low-dose applications. Other validation protocols for low-dose reuse applications have been recently published by Whitby et al. (2011).

6.4.3.3 Ozone The detection of pharmaceutically active and EDCs in reclaimed water has resulted in an increased interest in the application of ozone disinfection. Ozone is a mature disinfection technology with secondary benefits of removal of CECs as well as color removal. Additional research funded by the WRRF under project WRF-08-05 on use of ozone for water reclamation is ongoing, and a report on contaminant oxidation in reclaimed water using ozone is scheduled for release in 2013. With respect to disinfection, the mechanism of microbial inactivation is similar to chlorine in that it is a chemical process that disrupts cell membranes and nucleic acids, altering transport across the membrane. This causes cell lysis, causing irreversible damage to the DNA. The high oxidation potential of ozone makes it suitable for oxidizing CECs and other compounds that can cause taste and odor issues in indirect potable applications. It also breaks down larger organic compounds that can act as precursors to

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chlorinated DBPs and bring about an increase in UVT, thus leading to more energy-efficient UV disinfection following ozonation (Kleiser and Frimmel, 2000). While ozonation has substantial benefits, as of 2010, it was used at fewer than a dozen treatment plants in the United States, of which only two are specifically reuse applications: El Paso, Texas, and Gwinnett County, Ga. (Oneby et al., 2010). While ozone has been prevalent in the drinking water industry, it is important to recognize the growing body of ozone disinfection research in reuse, as documented in Ishida et al. (2008), which highlights novel approaches to the application of ozone for reclaimed water disinfection. The task of designing and operating ozone disinfection systems for wastewater reclamation may be approached in an alternative manner than utilized in the drinking water industry. Drinking water ozone disinfection is based on the traditional drinking water Ct concept, the product of contact time and ozone residual for dose determination (in mg-min/L). Application of the traditional drinking water Ct concept may be inappropriate for wastewater disinfection as significant bacterial reduction can be achieved prior to the appearance of an ozone residual, since ozone decays rapidly (Absi et al., 1993; Janex et al., 2000; Lazarova et al., 1998). Bacterial inactivation by ozone in wastewater disinfection is highly dependent on effluent quality. Compared to drinking water applications, the process is less dependent on contact time than ozone concentrations, once an initial amount of ozone is transferred to the wastewater (Tyrrell et al., 1995; Janex et al., 2000; Ishida et al., 2008). Although this observation may be specific to the target microorganism, the presence or absence of readily oxidizable materials seems to determine the importance of contact time (Sommer et al., 2004). Detailed research on filtered wastewater has resulted in conditional acceptance of ozone by the CDPH for reclaimed water disinfection. For all test conditions, this research demonstrated that a Ct below 1 mgmin/L met nondetectable total coliform counts and provided the 5-log virus barrier required by CDPH; thus, CDPH has set an ozone minimum Ct requirement of 1 mg-min/L (Ishida et al., 2008). It should be noted that Ct values greater than 1.0 mgmin/L have been reported to meet various reclaimed water coliform standards (WRRF, 2012a).

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The addition of hydrogen peroxide (H2O2) to ozone in wastewater has been shown to reduce bromate formation (Ishida et. al., 2008) where this is a concern due to the presence of bromide. Research reports conflicting results, and the reasons for these differences are not fully understood, although it is known to be related to water chemistry. Further, increasing the ozone contact time (while maintaining ozone residual) from 30 seconds to 120 seconds does not appear to substantially boost disinfection performance (WRRF, 2012a). Because of improvements in ozone generation and dissolution technologies in recent years, which improve the economics of the process along with increasing interest in addressing CECs, several new ozone systems for wastewater disinfection are under design, under construction, and recently in operation. In Anaheim, Calif., a 0.1 mgd (4.4 L/s) pressurized ozone reactor (HiPOx by APTwater) will be in operation by 2012 (Robinson, 2011). This system was installed as part of a combined effort to produce highquality reclaimed water and to educate the community. The Clark County Water Reclamation District has chosen to upgrade its treatment from sand filtration and UV to membrane filtration and ozone. The first 30 mgd (1,314 L/s) (average annual flow, peak flow of 45 mgd [1,972 L/s]) of this upgrade was under construction in 2012. A second upgrade of an additional 30 mgd (1,314 L/s) of average annual flow is under design (Drury, 2011).

parameters (Moce´-Llivina et al., 2003; Salveson et al., 2011). Pasteurization has been demonstrated at the city of Santa Rosa’s Laguna Wastewater Reclamation Plant, where validation testing was conducted as part of the CDPH program to review new technologies and provide conditional approval (often referred to as “Title 22” approval) (Salveson et al., 2007). Based upon this and other work, the CDPH approved pasteurization to meet the stringent “tertiary recycled water criteria” for specific minimum contact times and temperature. The economic value of pasteurization is favorable when waste heat can be captured and transferred for disinfection. Heat exchangers can be used to recapture heat from hot disinfected water to preheat undisinfected water, also cooling the disinfected effluent to just a few degrees above the influent undisinfected water. Example sources of waste heat include exhaust heat from a turbine fueled by natural gas, digester gas, or hot water. Favorable economics for pasteurization has been demonstrated in Ventura, Calif., where a 400 gpm (25 L/s) demonstration system (Figure 6-2) has been constructed and is in continuous operation. Because of the high cost of power at this utility, pasteurization is projected to save several million dollars in lifecycle costs compared to UV disinfection (US-CA-Pasteurization).

6.4.3.4 Pasteurization Pasteurization is a process of applying heat to a substance to inactivate pathogenic or spoilage microorganisms. The process was discovered by Louis Pasteur in 1864 and has since become standard practice in the food industry. Pasteurization has also become accepted practice in sewage sludge processing, with the goal of inactivating pathogens to achieve Class A Biosolids standards. Thermal inactivation of microorganisms may depend on a number of factors: characteristics of the organism, stress conditions for the organism (e.g., nutrient limitation), growth stage, characteristics of the medium (e.g., heat penetration, pH, presence of protective substances like fats and solids, etc.), and temperature and exposure time combinations. In design of pasteurization systems, temperature and exposure time combinations are the dominant

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Figure 6-2 Pasteurization demonstration system in Ventura, Calif.

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Figure 6-3 Example WRF treatment train that includes UV/H2O2 AOP

6.4.3.5 Ferrate Ferrate was explored in the 1970s as a replacement chemical for chlorine, but prior synthesis methods made its utilization cost prohibitive. With recent advances in new on-site production methods of ferrate, it has the potential to be applied as an alternative to other widely-practiced oxidation and disinfection processes. Research has demonstrated that ferrate can be an extremely competitive oxidizing agent for disinfection processes, with the key benefit of minimizing by-product formation. Ferrate chemistry results from formation of iron in the plus 6 oxidation +6 state, or Fe , and is a powerful oxidant, depending upon the pH of the solution. As pH will dictate the stability and reactivity of ferrate in solution, testing is required to determine the conditions under which ferrate disinfection is feasible. There are many reports on the use of ferrate in wastewater disinfection, and an excellent summary of the most relevant literature has been provided in Skaggs et al. (2009 and 2008). The on-site generation of ferrate requires bulk caustic, bulk ferric chloride, and bulk liquid sodium hypochlorite solutions. The components of a ferrate disinfection system are similar to that of a liquid hypochlorination system with the exception of the addition of an on-site generation system. Additional solids are produced in ferrate disinfection, so solids handling may be an additional component of a ferrate disinfection system. Site-specific testing must be conducted to determine the required disinfection dose. While there have been numerous laboratory and pilotscale investigations, the first full-scale installation of ferrate at the 100 mgd (4,400 L/s) East Bank treatment plant in New Orleans, La., is not anticipated to be implemented until after 2012. The technology was selected for this application due to its advantages over other technologies, including the fact that it can

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provide oxidation and disinfection in the same application, similar to ozone. This allows the disinfection process to also address EDCs, which were a concern for reuse of the water at the East Bank WWTP for wetlands restoration (AWWA, 2010).

6.4.4 Advanced Oxidation AOPs are a class of water treatment technologies, including UV/H2O2, ozone/H2O2, ozone/UV, UV/TiO2 (titanium dioxide), and a variety of Fenton reactions (Fe/H2O2, Fe/ozone, Fe/H2O2/UV) (Asano et al., 2007; Stasinakis, 2008; Munter, 2001) that can be added to the end of a treatment train, as shown in Figure 6-3. These technologies have a broad range of applications, from reducing the CECs and toxicity of industrial effluent and wastewater to finishing water for high-tech industries (Munter, 2001; WRRF, 2012f). This process is especially valuable for reclaimed water treatment for potable applications because of its ability to address PPCPs and EDCs that are not significantly removed during conventional wastewater treatment processes (Miège et al., 2008). Although a variety of base treatment technologies can drive AOPs, each AOP is similar in that it is designed to generate highly reactive, nonspecific intermediate species (such as hydroxyl radicals and superoxide radicals) (Glaze et al., 1987). There are several technologies available for advanced oxidation that show promise for reuse applications. AOPs are designed to take advantage of the high electrochemical oxidation potential of radical species, combining parallel disinfection and oxidation processes as shown in Table 6-8. The hydroxyl radicals formed in an AOP work in parallel to the primary disinfectant by breaking apart organic compounds, resulting in the transformation of toxic organic compounds into less-toxic daughter

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compounds (Stasinakis, 2008). Hydroxyl radical formation and availability is affected by pH, but only at pH extremes (Arakaki, 1999); at typical pH values, hydroxyl radical formation rates will not vary significantly (Watts et al., 1994). Free radicals quickly react with electron acceptors in water, and as a result wastewater has a high scavenging capacity (RosarioOrtiz et al., 2010). Because of this, organic species present in treated wastewater can compete for hydroxyl radicals and it is less likely that the preferred reaction, the oxidation of TrOCs, will take place. Table 6-8 Electrochemical oxidation potential (EOP) for several disinfectants (adapted from Tchobanoglous et al., 2003) EOP [V]

EOP Relative to Chlorine

Hydroxyl Radical

2.80

2.05

Ozone

2.08

1.52

1.81

1.33

Hydrogen Peroxide

1.78

1.3

Hypochlorite

1.49

1.1

Chlorine

1.36

1

Chlorine Dioxide

1.27

0.93

Oxidizing Agent

Peracetic Acid

1

1

Peracetic acid data courtesy of Enviro-Tech Chemical Services Inc.

Advanced oxidation processes are most commonly used in potable reuse applications to address treatment objectives that include recalcitrant organic compounds, such as PPCPs, and a wide range of potential EDCs. Compared to other treatment alternatives, such as activated carbon, AOPs also disinfect a wide variety of microbial targets and result in an overall removal of pathogens and CECs (WRRF, 2012g), as opposed to simply sequestering compounds via adsorption or physical separation. UVbased AOPs are also frequently employed to destroy nitrosamines, particularly the carcinogenic DBP NDMA in potable reuse applications [US-CA-San Diego]. This is in response to regulations on NDMA in California, which is ahead of EPA in regulating this compound; EPA placed NDMA (and the other five nitrosamines) on its second Unregulated Contaminant Monitoring List (UCMR2) in 2006. When the operational costs of advanced oxidation systems are compared to the total operational expenses of the treatment process for potable reuse applications, these costs are marginal. In a recent

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study from Australia, the electrical costs of running the UV system were only 3.5 percent of the total energy costs, and H2O2 costs made up only 4 percent of the total costs of the chemicals used on-site (Poussade et al., 2009). WRRF (2012a) demonstrated that the lowest-cost AOP process following media filtration, MF filtration, and UF filtration is ozone. More expensive technologies following media, MF, and UF filtration included UV/H2O2, ozone/H2O2, TiO2/UV, peracetic acid with UV, and several other technologies. Following RO treatment, the optimum AOP system is dependent on the target compound. If NDMA destruction is the key target, UV/H2O2 will be the lowest-cost treatment; if an organic compound is the primary target, likely ozone/H2O2 or ozone will be the lowest-cost technology. In some reuse scenarios, augmentation of existing potable water supplies is required. The practice of IPR continues to grow in acceptance and application. One of the main drivers for this acceptance is the growing public knowledge of water treatment, particularly the extensive treatment the wastewater undergoes before being considered safe for potable consumption. A vital component of the extensive treatment train in IPR is the combined use of UV light and H2O2. In IPR applications, UV/H2O2 not only provides disinfection, but also destroys CECs (Drewes et al., 2002). Examples include the OCWD and the WBMWD, whose IPR projects provide groundwater replenishment, and the community of Big Spring, Texas, which has begun a project that will purify wastewater to quality better than drinking water for the augmentation of local surface water. In these cases, an integrated membrane system (IMS) provides significant pretreatment to the UV/H2O2 AOP. The full-scale Advanced Water Purification Facility at the OCWD’s Groundwater Replenishment System, commissioned in 2008, uses filtered secondary wastewater effluent from a neighboring WWTP and treats it to water that meets all drinking water quality standards. The 70-mgd (3,100 L/s) system consists of MF, RO, and UV/H2O2. The UV/H2O2 treatment step at OCWD consists of a LPHO amalgam lamp UV system comprised of multiple parallel trains of stacked UV chambers (connected in series). To verify predicted NDMA reductions, this UV/H2O2 system was tested to demonstrate both NDMA destruction and microorganism disinfection, showing that the system was effective for both treatment objectives.

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6.4.5 Natural Systems Natural filtration processes take advantage of intrinsic characteristics of riverbanks, aquifers, and wetlands comprised of media—soil and plants—that can filter water and in some cases provide a surface for biofilm growth that can biologically oxidize or reduce contaminants. Two natural treatment approaches include wetlands and soil aquifer filtration (which also includes riverbank filtration for the purposes of this discussion). The principles of how these natural filtration processes can be used to confer additional treatment are described in the EPA Process Design Manual for Land Treatment of Municipal Wastewater Effluents (EPA, 2006).

6.4.5.1 Treatment Mechanisms in Natural Systems Natural systems have the potential to reduce or remove pathogens, organic carbon, contaminants of concern, and nutrients during sub-surface transport. As reclaimed water filters through the subsurface, physical, biological, and chemical water quality improvement occurs during SAT where spreading basins are used (Section 2.3.3.2). During ASR, vadose zone injection, or direct injection, these mechanisms can also occur to a varying extent; this is especially true of ASR systems, in which sub-surface residence time can be highly variable. Pathogens. Pathogens are a major concern in all reclaimed water systems, and the highest risk associated with pathogens is ingestion. Pathogen removal efficacy for SAT systems via filtration and disinfection is described in Demonstration of Filtration and Disinfection Compliance through SAT (WRRF, 2012g). Pathogen removal during SAT is most efficient during unsaturated flow but the unsaturated zone is bypassed by direct injection into the aquifer during ASR. For ASR, treatment efficiency determination is site specific. Furthermore, pathogen removal during ASR is less efficient when non-porous media is present, for example, recharge into bedrock (e.g. basalt) rather than into granular aquifers (sand). Concerns over pathogens have resulted in the implementation of travel time requirements for environmental buffers in IPR systems. Travel times are average values and some groundwater takes a faster path and arrives sooner than average. Travel times are most accurately calculated for only porous media aquifers. In non-porous media aquifers, travel times are best determined using site specific field tracer

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tests. In either case, travel times are uncertain and are especially uncertain for non-porous media. In California, travel time requirements range from 6 to 12 months, depending on the percentage of reclaimed water in the IPR system. In 2009, Massachusetts adopted a 6-month travel time requirement for environmental buffers in IPR systems. The retention times required for environmental buffers ranges from 50 days to 12 months, and this has a major impact on design and implementation. The AwwaRF study titled “Water Quality Improvements during Aquifer Storage and Recovery” (2005) reported on extensive laboratory and field studies on the survival of the bacteria, E. coli, a nonpathogenic indicator. A summary of studies on E. coli decay rates revealed that most researchers found decay rates of 0.1/d or greater when studying the decay of E. coli in a sub-surface environment (Roslev et al., 2004). Many of these studies were conducted under controlled conditions in groundwater without the effects of straining and sorption (filtration). Therefore, decay alone may result in 5-log removal of E. coli in less than 20 days during sub-surface transport. However, E. coli decay rates do not inform pathogenic human viral or parasitic protozoan decay rates. Concern over viruses has prompted continued research on virus transport and survival in environmental buffers. Soil saturation and aquifer flow type (porous or non-porous media), media composition, ground water pH, and virus strain all interact to affect the sorptive capacity and virus die-off rate in soils and aquifers. Because viral subsurface inactivation rates are an estimate, a second barrier with reliable, effective disinfection is recommended. Furthermore, virus removal by sorption is an active research area and remains difficult to predict in field studies. Similar concerns over protozoa have been raised because Cryptosporidium oocysts and Giardia cysts have been found in groundwater (Bridgman et al. 1995; Hancock et al. 1998) and in reclaimed water (Gennancaro et al., 2003; Huffman et al., 2006) including infectious Giardia. And, there have been Cryptosporidium and Giardia outbreaks, some associated with heavy rainfall (Bridgman et al. 1995; Willocks et al. 1998; Rose et al. 2000; Curriero et al. 2001), with research revealing that Cryptosporidium oocysts and Giardia cysts can be transported in the subsurface under normal conditions, soil, especially when preferential porous media flow paths exist

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(Darnault et al. 2003 and Park et al., 2012). Additional research into the transport of protozoan pathogens is needed. Organic Carbon. Residual organic carbon is a concern in IPR systems because these compounds are associated with a broad spectrum of potential health concerns (Asano, 1998). Three groups of residual organic chemicals require attention (Drewes and Jekel, 1998): 1) natural organic matter (NOM) present in most water supplies, 2) CECs added by consumers and generated as DBPs during the disinfection of water and wastewater, and 3) soluble microbial products (SMPs) formed during the wastewater treatment process and resulting from the decomposition of organic compounds. NOM and SMPs are mixtures of compounds that cannot be effectively measured individually. When NOM and SMPs are measured as a group, the concentrations of organic carbon are typically measured in the mg/L range; CECs are typically present in the μg/L to ng/L range. Most waters contain NOM, and reclaimed waters contain a mixture of NOM and SMPs (Drewes and Fox, 2000). Most reclaimed waters used in managed aquifer recharge systems receive limited characterization of NOM and/or SMPs that comprise the bulk of the organic carbon compounds present. Typically, these compounds are quantified by DOC measurements and ultraviolet absorbance (UVA) (Fox and Drewes, 2001). Organic compounds are removed during sub-surface transport by a combination of filtration, sorption, oxidation/reduction, and biodegradation. Biodegradation is the key sustainable removal mechanism for organic compounds during sub-surface transport (Fox et al., 2005; AWWARF, 2001). The concentrations of NOM and SMPs are reduced during sub-surface transport as high molecular weight compounds are hydrolyzed into lower molecular weight compounds and the lower molecular weight compounds serve as substrate for microorganisms (Drewes et al., 2006). Synthetic organic compounds at concentrations too low to directly support microbial growth may be co-metabolized, as NOM and SMPs serve as the primary substrate for growth (RauschWilliams et al, 2010, Nalinakumari et al, 2010). During sub-surface transport, the transformation of organic compounds may be divided up into several different regimes defined as short-term

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transformations where relatively fast reactions occur and long-term transformations where recalcitrant compounds continue to transform at slower rates over time (Fox and Drewes, 2001). Easily biodegradable carbon is transformed within a time-scale of days. The environmental buffer of IPR systems typically contains much longer time-scale over which DOC can continue to be transformed. Constituents of Concern. The removal of CECs in general tends to parallel the removal of DOC. Easily biodegradable constituents of concern, such as caffeine and 17β-Estradiol, tend to degrade on a timescale of days while more refractory compounds, such as NDMA and sulfamethoxazole, tend to degrade over a time-scale of weeks to months (Dickerson et al., 2008). Persistent compounds, such as carbamezapine and primodone, can persist for months or years in an environmental buffer (Clara et al., 2004, Heberer, 2002). The transformation of organic constituents of concern can depend on the presence of biodegradable dissolved organic carbon (BDOC) because the concentrations of constituents of concern are very low and may not support growth (Rausch-Williams et al., 2010; Nalinakumari et al., 2010). Nitrogen. Reclaimed water that has not been nitrified or denitrified may contain greater than 20 mg/L of ammonia-nitrogen, which can exert over 100 mg/L of nitrogenous oxygen demand. The majority of studies on the fate of nitrogen have been done in the vadose zone because wet/dry cycles can result in alternating aerobic/anoxic conditions (Miller et al., 2006). Alternating aerobic/anoxic conditions may facilitate nitrogen cycling, and greater than 70 percent nitrogen removal has been observed in the vadose zone at the Tucson Sweetwater Underground Storage and Recovery Facility. Other facilities have also sustained nitrogen removal in the vadose zone when alternating aerobic/anoxic conditions were maintained (Kopchynski et al., 1996). This mechanism for removal is not dependent on the retention time in the buffer zone but is a function of recharge basin operation. The aquifer below a vadose zone becomes anoxic when ammonia is present in recycled water at levels sufficient to deplete oxygen in percolating water (AWWARF, 2001). Reduction of nitrate will occur as a function of retention time under anoxic conditions as nitrate is used as the electron acceptor for organic compound transformations. If nitrate becomes depleted, more reduced conditions can develop,

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leading to reduced transformation of organic compounds and the release of soluble iron and manganese. Indirect potable reuse systems are not operated under these conditions because the produced water will require post-treatment. These conditions do occur in bank filtration systems in Europe, and post-treatment for iron and manganese is commonly practiced.

6.4.5.2 Wetlands Wetland treatment technology has been under development, with varying success, for more than 40 years in the United States. A great deal of research has been performed documenting the ability of wetlands, both natural and constructed, to provide consistent and reliable water quality improvement. With proper execution of design and construction elements, constructed wetlands exhibit characteristics that are similar to natural wetlands in that they support similar vegetation and microbes to assimilate pollutants. In addition, constructed wetlands provide wildlife habitat and environmental benefits that are similar to natural wetlands. Constructed wetlands are effective in the treatment of BOD, TSS, nitrogen, phosphorus, pathogens, metals, sulfates, organics, and other toxic substances. There are hundreds of wastewater treatment wetlands operating in the United States today (Source: EPA832-R-93-005). Water quality enhancement is provided by transformation and/or storage of specific constituents within the wetland. The maximum contact of reclaimed water within the wetland will ensure maximum treatment assimilation and storage. This is due to the nature of these processes. If optimum conditions are maintained, nitrogen and BOD assimilation in wetlands will occur indefinitely, as they are primarily controlled by microbial processes and generate gaseous end products. In contrast, phosphorus assimilation in wetlands is finite and is related to the adsorption capacity of the soil and long-term storage within the system. The wetland can provide additional water quality enhancement (polishing) to the reclaimed water product. A review of wastewater recycling and reuse alternatives performed by Carey and Migliaccio (2009) indicate that natural or constructed wetlands can, in certain instances, replace other advanced wastewater treatment processes, removing up to 79 percent of total nitrogen and 88 percent of total phosphorus concentrations.

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In addition to our current state of knowledge on the design and performance of known pollutants in surface-flow and subsurface-flow constructed wetland systems, including BOD, TSS, nutrients, and pathogens, a description of removal of wastewaterderived organic compounds (WDOCs) is provided in Evaluate Wetland Systems for Treated Wastewater Performance to Meet Competing Effluent Quality Goals (WRRF, 2011b). This report provides identification of specific chemicals that best represent or act as surrogates for various classes of pollutants and WDOCs, which supports continuing consideration of constructed wetlands as an option for providing polishing treatment to protect aquatic ecosystems and potable water supplies. A series of long successful examples of wetlands treatment projects are described in Constructed Wetlands for Wastewater Treatment and Wildlife Habitat: 17 Case Studies (EPA, 1993). More recently, constructed wetlands have been employed in Phoenix, Ariz., where in 1990 city managers were faced with needed improvements at the WWTP to meet new state water quality standards. After determining that upgrading the plant might cost as much as $635 million, managers looked for a more cost-effective solution to provide final treatment for discharge into the Salt River. A preliminary study suggested that a constructed wetland system would address discharge water quality requirements while supporting highquality wetland habitat for birds, including endangered species, and protect downstream residents from flooding. These benefits would be achieved at a lower cost than retrofitting the existing treatment plant. As a result, the 12-acre Tres Rios Demonstration Project began in 1993 with assistance from the USACE, the BOR, and EPA’s Environmental Technology Initiative. The Tres Rios treatment wetlands are currently the largest of their kind in Arizona. Highly-treated effluent from the 91st Avenue WWTP was first delivered to a 98-ac cell in July 2010 with discharges regulated under a NPDES permit overseen by EPA and an Aquifer Protection Permit as mandated by the ADEQ. The remaining two wetland cells are developing mature wetland vegetation and were brought online late in 2011. Treated water from the Tres Rios wetlands is reused to support approximately 137 ac of wetland and riparian habitat along the north bank of the Salt River while at the same time conveying water to satisfy contractual obligations to the Buckeye Water Conservation District. This site, which serves as a

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home for thousands of birds and other wildlife, will be open to the public and will serve as a platform for environmental education and passive recreation [USAZ-Phoenix].

Pilot Studies to Design and Model Soil Aquifer Treatment Systems (AwwaRF, 1998). Because the soil and aquifer are natural treatment systems, SAT systems have a positive impact on public acceptance.

Thus, while in most reclaimed water wetland projects the primary intent is to provide additional treatment of effluent prior to discharge from the wetland, it is also important to consider the design considerations that will maximize wildlife habitats, and thereby provide important ancillary benefits, which are discussed in Section 3.4.1.1. With respect to constructed wetlands, there are some well-established types of treatment systems, including free water surface wetlands that have open water areas and emergent vegetation, and subsurface flow (SSF) wetlands in which water does not flow above the surface of the media. There are several key documents available that provide information that can be used to assist in the design of wetland treatment systems, including: Treatment Wetlands, Second Edition; Treatment Wetlands; Small-scale Constructed Wetland Treatment Systems: Feasibility, Design Criteria, and O&M Requirements; Constructed Wetlands for Pollution Control: Process, Performance, Design and Operation; Water Environment Federation Manual of Practice FD-16. Natural Systems for Wastewater Treatment, Chapter 9: Wetland Systems; and Free Water Surface Wetlands for Wastewater Treatment.

6.4.6 Monitoring for Treatment Performance

6.4.5.3 Soil Aquifer Treatment Systems Essentially, SAT is a low-technology, advanced wastewater treatment system. The process is most commonly implemented at spreading basins (Section 2.3.3.2), where reclaimed water percolates into the soil, consisting of layers of loam, sand, gravel, silt, and clay. As the reclaimed water filters through the soil, these layers allow it to undergo further physical, biological, and chemical treatment through the SAT (WRRF, 2012g). SAT systems require unconfined aquifers, vadose zones free of restricting layers, and soils that are coarse enough to allow for sufficient infiltration rates but fine enough to provide adequate filtration. This process of filtration, in which the unsaturated or vadose zone acts as a natural filter and can remove essentially all suspended solids, biodegradable materials, bacteria, viruses, and other microorganisms, results in significant reductions in nitrogen, phosphorus, and heavy metals concentrations. Additional information on piloting and design of SAT systems is presented in Soil Treatability

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Reliable monitoring to detect process failures and assess water quality in a reuse scheme have been recommended in several recent reference documents (NRC, 2012; WRRF, 2011c; Colford et al., 2009) and, in summary, should include: 1. A source control program documenting contaminant