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. 
ii 2012 Guidelines for Water Reuse

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.
2012 Guidelines for Water Reuse iii

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

Lek Kadeli

Acting Assistant Administrator

Office of Research & Development

U.S. EPA

Eric Postel

Assistant Administrator

Bureau for Economic Growth, Education & Environment

USAID
iv 2012 Guidelines for Water Reuse

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:

 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 v 

 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. 
vi 2012 Guidelines for Water Reuse

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
2012 Guidelines for Water Reuse vii

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 
viii 2012 Guidelines for Water Reuse

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
2012 Guidelines for Water Reuse ix

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 
x 2012 Guidelines for Water Reuse

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 
2012 Guidelines for Water Reuse xi

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 
xii 2012 Guidelines for Water Reuse

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 
2012 Guidelines for Water Reuse xiii

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 
xiv 2012 Guidelines for Water Reuse

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
2012 Guidelines for Water Reuse xv

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
xvi 2012 Guidelines for Water Reuse

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, BOD5 ................................................................. 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 
2012 Guidelines for Water Reuse xvii

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
xviii 2012 Guidelines for Water Reuse

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.
2012 Guidelines for Water Reuse xix

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
xx 2012 Guidelines for Water Reuse

 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

Constantia Achileos, MSc

Sewerage Board of Limassol Amathus

Limassol, Cyprus

Robert Adamski, P.E., BCEE

Gannett Fleming

Woodbury, NY

Pruk Aggarangsi, PhD

Energy Research and Development InstituteNakornping, 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

Robert Angelotti

Upper Occoquan Sewage Authority (UOSA)

Centreville, VA

David Arseneau, P.Eng, MEPP

AECOM

Kitchener, Ontario, Canada

Shelly Badger

City of Yelm

Yelm, WA

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 xxi

*Katherine Bell, PhD, P.E., BCEE

CDM Smith

Nashville, TN

Ignacio Benavente, Eng, PhD

University of Piura

Piura, Peru

Alon Ben-Gal, PhD

Agricultural Research Organization, Gilat Research 

Center

Negev, Israel

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

Sally Brown, PhD

University of Washington

Seattle, WA

Tom Bruursema

NSF International

Ann Arbor, MI

Laura Burton

CDM Smith

Cambridge, MA

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
xxii 2012 Guidelines for Water Reuse

Joseph Cleary, P.E., BCEE

HDR/HydroQual

Mahwah, NJ

Tracy Clinton, P.E.

Carollo Engineers

Walnut Creek, CA

Stacie Cohen

CDM Smith

Cambridge, MA

Octavia Conerly

EPA Office of Science and Technology

Washington, D.C. 

Teren Correnti

CDM Smith

Carlsbad, CA

*Joseph Cotruvo, PhD

Joseph Cotruvo and Associates

Washington, D.C. 

Jim Coughenour

City of Phoenix

Phoenix, AZ

*Patti Craddock, P.E.

Short Elliott Hendrickson Inc.

St. Paul, MN

Donald Cutler, P.E.

CDM Smith

Carlsbad, CA

*Allegra K. da Silva, PhD

CDM Smith

Wethersfield, CT

Walter Daesslé-Heuser, PhD

Autonomous University of Baja California (UABC)

Ensenada, Baja California, Mexico

Arnon Dag, PhD

Agricultural Research Organization, Gilat Research 

Center

Gilat, Israel

Liese Dallbauman, PhD

PepsiCo

Chicago, IL

Marla Dalton

City of Raleigh, NC

Raleigh, NC

Dnyanesh V Darshane, PhD, MBA

The Coca-Cola Company

Atlanta, GA

William Davis

CDM Smith

Denver, CO

Gary Dechant

Laboratory Quality Systems

Grand Junction, CO

Gina DePinto

Orange County Water District

Fountain Valley, CA

Clint Dolsby

City of Meridian

Meridian, ID

Amy Dorman, P.E.

City of San Diego

San Diego, CA

Karen Dotson, Retired

Tucson Water

Tucson, AZ

*Pay Drechsel, PhD

International Water Management Institute (IWMI)

Colombo, Sri Lanka

Jörg Drewes, PhD

Colorado School of Mines

Golden, CO

William Dunivin

Orange County Water District

Fountain Valley, CA

Yamaji Eiji

University of Tokyo

Tokyo, Japan

Mark Elbag

Town of Holden

Holden, MA

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 xxiii

Kraig Erickson, P.E.

RMC Water and Environment

Los Angeles, CA

Ramiro Etchepare, MSc

Universidade Federal do Rio Grande do Sul

Port Alegre, Brazil

Patrick J. Evans, PhD

CDM Smith

Bellevue, WA

Rob Fahey, P.E.

City of Clearwater

Clearwater, FL

Johnathan Farmer

Jones Hawkins & Farmer, PLC

Nashville, TN

MerriBeth Farnham

HD PR Group

Fort Myers, FL

James Ferguson, P.E.

Miami Dade Water and Sewer Department

Miami, FL

Diana Lila Ferrando, Eng, MSc

University of Piura

Piura, Peru

Colin Fischer

Aquacell

Leura, New South Wales, Australia

*Peter Fox, PhD

Arizona State University

Tempe, AZ

Mary Fralish

City of Mankato

Mankato, MN

Tim Francis, P.E., BCEE

ARCADIS

Phoenix, AZ

Steven A. Friedman, P.E., PMP

HDR Engineering

Riverside, CA

Paul Fu , PhD, P.E.

Water Replenishment District

Lakewood, CA

Naoyuki Funamizu , Dr. Eng.

Hokkaido University

Sapporo, Japan

Jocelyn L. Cheeks Gadson, PMP

The Coca-Cola Company

Atlanta, GA

Elliott Gall

University of Texas

Austin, TX

Patrick Gallagher, JD

CDM Smith

Cambridge, MA

*Monica Gasca, P.E.

Los Angeles County Sanitation Districts

Whittier, CA

Daniel Gerrity, PhD

UNLV

Las Vegas, NV

Patrick Girvin

GE

Boston, MA

Victor Godlewski

City of Orlando

Orlando, FL

Scott Goldman, P.E., BCEE

RMC Water and Environment

Irvine, CA

Fernando Gonzalez

Degremont, S.A. de C.V.

Mexico City, Mexico

Albert Goodman, P.E.

CDM Smith

Louisville, KY

Leila Goodwin, P.E.

Town of Cary

Cary, NC

Charles G. Graf, R.G.

Arizona Department of Environment Quality

Phoenix, AZ

Thomas Grizzard, PhD, P.E.

Virginia Tech

Manassas, VA
xxiv 2012 Guidelines for Water Reuse

Amit Gross, PhD

Ben Gurion University of the Negev

Sede Boqer, Midreshet Ben Gurion, Israel

*Elson Gushiken

ITC Water Management, Inc.

Haleiwa, Hawaii

Juan M. Gutierrez, MS

Javeriana University

Bogota, Colombia

Brent Haddad, MBA, PhD

UC Santa Cruz

Santa Cruz, CA

Josef Hagin, PhD

Grand Water Research Institute Technion – Israel 

Institute of Technology

Haifa, Israel

*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

Mark Hilty, P.E.

City of Franklin TN

Franklin, TN

Grant Hoag, P.E.

Black and Veatch

Irvine, CA

Rita Hochstrat, MTechn.

University of Applied Sciences Northwestern 

Switzerland

Muttenz, Switzerland

Abigail Holmquist, P.E.

Honeywell

Des Plaines, IL

Robert Hultquist

California Department of Public Health

El Cerrito, CA

Christopher Impellitteri, PhD

US Environmental Protection Agency

Cincinnati, OH

Ioanna Ioannidou, MSc, MBA

Larnaca Sewerage and Drainage Board

Larnaca, Cyprus

Kevin Irby, P.E.

CDM Smith

Raleigh, NC

*Jillian Jack, P.E.

CDM Smith

Atlanta, GA

JoAnn Jackson, P.E.

Brown and Caldwell

Orlando, FL

Afsaneh Janbakhsh, MSc, Cchem, MRSC, Csci

Northumbrian Water Ltd

Chelmsford, Essex, United Kingdom

Veronica Jarrin, P.E.

CH2M HILL

Atlanta, GA

Raymond Jay

Metropolitan Water District

Los Angeles, CA

Blanca Jiménez-Cisneros, PhD

Universidad Nacional Autónoma de México

Mexico City, Mexico

Mohammad Jitan, PhD

National Center for Agricultural Research and 

Extension

Baq'a, Jordan

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 xxv

Grace Johns, PhD

Hazen and Sawyer

Hollywood, FL

Daniel Johnson, P.E.

CDM Smith

Atlanta, GA

Jason Johnson, P.E.

CDM Smith

Miami, FL

Geoff Jones

Barwon Water

Geelong, Victoria, Australia

Jayne Joy, P.E.

Eastern Municipal Water District

Perris, CA

Graham Juby, PhD, P.E.

Carollo Engineers

Riverside, CA

Bader Kassab, MSc

USAID

Baq'a, Jordan

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

Stuart Khan, PhD

University of South Wales

Sydney, New South Wales, Australia

Robert Kimball, P.E., BCEE

CDM Smith

Helena, MT

Katsuki Kimura, Dr.Eng.

Hokkaido University

Sapporo, Japan

Kenneth Klinko, P.E.

CDM Smith

Carlsbad, CA

*Nicole Kolankowsky, P.E.

Black and Veatch

Orlando, FL

Ariel Lapus

USAID-PWRF Project

Manilla, Philippines

Cory Larsen, P.E.

North Carolina Department of Environment and 

Natural Resources

Raleigh, NC

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 of Public Health and 

Environment

Denver, CO
xxvi 2012 Guidelines for Water Reuse

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

W. Kirk Martin, P.G.

CDM Smith

Ft. Myers, FL

Pablo Martinez

SAWS

San Antonio, TX

Ignacio Martinez

Texas A&M AgriLife Research Center at El Paso

El Paso, TX

Jim Marx, MSc, P.E.

AECOM

Washington, D.C. 

*Robert Matthews, P.E., DEE

CDM Smith

Rancho Cucamungo, 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

Matt McTaggart, P.Eng, R.Eng

AECOM

Sharon Megdal, PhD

University of Arizona

Tucson, AZ

Leopoldo Mendoza-Espinosa, PhD

Autonomous University of Baja California (UABC)

Ensenada, Baja California, Mexico

Tracy Mercer, MBA

City of Clearwater

Clearwater, FL

Mark Millan

Data Instincts

Windsor, CA
2012 Guidelines for Water Reuse xxvii

Wade Miller

WateReuse Association

Alexandria, VA

*Dianne Mills

CDM Smith

Charlotte, NC

Seiichi Miyamoto, PhD

Texas A&M AgriLife Research Center at El Paso

El Paso, TX

Jeff Moyer

Rodale Institute

Kutztown, PA 

Rafael Mujeriego, PhD

Universidad Politécnica de Cataluña

Barcelona, Spain

Richard Nagel, P.E.

West Basin Municipal Water Districts

Carson, CA

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

Tressa Nicholas

Idaho Department of Environmental Quality

Boise, ID

Joan Oppenheimer, BCES

MWH

Arcadia, CA

Kerri Jean Ormerod

University of Arizona

Tucson, AZ

David Ornelas

El Paso Water Utilities

El Paso, TX

Alysia Orrel

CDM Smith

Newport News, VA

John Emmanuel T. Pabilonia

USAID

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
xxviii 2012 Guidelines for Water Reuse

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

Joseph Quicho

City of San Diego

San Diego, CA

Daphne Rajenthiram

CDM Smith

Austin, TX

Alison Ramoy

SWFWMD

Brooksville, FL

Laura Read

Tufts University

Medford, MA

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

Joel A. Rosenfield

The Coca-Cola Company

Atlanta, GA

Debra Ross

King County Wastewater Treatment Division

Seattle, WA

Jonathan Rossi

Western Municipal Water District

Riverside, CA

Suzanne Rowe, P.G., C.HG.

CDM Smith

Irvine, CA
2012 Guidelines for Water Reuse xxix

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

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
xxx 2012 Guidelines for Water Reuse

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

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 xxxi

*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

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
xxxii 2012 Guidelines for Water Reuse

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. 

Phil Berger, PhD

EPA Office of Ground Water and Drinking Water

Washington, D.C. 

Veronica Blette

EPA Office of Wastewater Management

Washington, D.C. 

Octavia Conerly

EPA Office of Science and Technology

Washington, D.C. 

Michael J. Finn

EPA Office of Ground Water and Drinking Water

Washington, D.C. 

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. 

Cheryl McGovern

EPA Region 9

San Francisco, CA

George Moore

EPA Office of Research and Development

Cincinnati, OH

Dan Murray, P.E., BCEE 

EPA Office of Research and Development

Cincinnati, OH

Joseph Morris

Tinker AFB

Midwest City, OK 

Tressa Nicholas, MSCE

Idaho Department of Environmental Quality Water 

Quality Division

Boise, ID

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 xxxiii

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
xxxiv 2012 Guidelines for Water Reuse

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 1-1 

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 

national overview of 

the status of reuse 

regulations and clarify 

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 

Organization (WHO) Guidelines for the Safe Use of 

Wastewater, Excreta and Greywater. 

Figure 1-1

The 2004 EPA Guidelines for 

Water Reuse has had global 

influence.

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 
Chapter 1 | Introduction

1-2 2012 Guidelines for Water Reuse

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. 

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.

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.
Chapter 1 | Introduction

2012 Guidelines for Water Reuse 1-3 

Table 1-1 Organization of 2012 Guidelines for Water Reuse

Chapter Overview of Contents

Chapter 2–Planning and 

Management 

Considerations

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. 

The steps that should be considered in the planning stage as part of an integrated water 

resources plan are then presented, followed by an overview of key considerations for managing 

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
Chapter 1 | Introduction

1-4 2012 Guidelines for Water Reuse

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. 

Water reclamation: The act of treating municipal 

wastewater to make it acceptable for reuse.

Water reuse: The use of treated municipal wastewater 

(reclaimed water). Other alternate sources of water, 

including graywater and stormwater, are discussed in 

Chapter 2. 

Wastewater: Used water discharged from homes, 

business, industry, and agricultural facilities. 

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).

 

Table 1-2 Categories of water reuse applications

Category of reuse Description

Urban Reuse

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

Agricultural 

Reuse 

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

Impoundments

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 

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

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

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
Chapter 1 | Introduction

2012 Guidelines for Water Reuse 1-5 

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.). 

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). 

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. 

(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).

1.4.2 Water-Energy Nexus

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. 

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 
Chapter 1 | Introduction

1-6 2012 Guidelines for Water Reuse

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).

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). 

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

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].
Chapter 1 | Introduction

2012 Guidelines for Water Reuse 1-7 

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
Chapter 1 | Introduction

1-8 2012 Guidelines for Water Reuse

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 

<http://www.water.ca.gov/swpao/notices.cfm>. 

California Energy Commission. 2005. Final Staff Report, 

California’s Water-Energy Relationship, CEC-700-2005-011-

SF. Retrieved August 2012 from 

<http://www.energy.ca.gov/2005publications/CEC-700-2005-

011/CEC-700-2005-011-SF.PDF>.

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 

<http://pubs.usgs.gov/circ/1344/>.

National Conference of State Legislatures (NCSL). 2009. 

Overview of the Water-Energy Nexus in the U.S. Retrieved 

August 2012 from <http://www.ncsl.org/issues-research/envres/overviewofthewaterenergynexusintheus.aspx>. 

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 

<http://www.census.gov/population/international/data/worldp

op/table_population.php>. 

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). 2012. 

Energy/Water. Retrieved August 2012 from

<http://water.epa.gov/action/energywater.cfm>.

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 2-1 

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.

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. 

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 

heavily discharge wastewater and stormwater into 

receiving waters.

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 

Figure 2-1

Traditional versus Integrated Water Management 

(adapted from O’Connor et al., 2010)

Beneficial reuse of stormwater

(e.g., groundwater recharge)

Reclaimed water Reduced flows 

from BMPs

Wastewater

Receiving 

Waters

Water Supply Stormwater

dry

weather

wet

weather

Wastewater

Receiving 

Waters

Water Supply Stormwater

dry

weather

wet

weather

Traditional Water Management (Non-integrated Water Resources)

Total Water Management (Integrated Water Resources)
Chapter 2 | Planning and Management Considerations

2-2 2012 Guidelines for Water Reuse

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,

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-3 

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 

(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. 
Chapter 2 | Planning and Management Considerations

2-4 2012 Guidelines for Water Reuse

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 

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-5 

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 

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 
Chapter 2 | Planning and Management Considerations

2-6 2012 Guidelines for Water Reuse

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 

million gallons (160,000 m3

) of reclaimed water are

being used each scheduled watering day, and 19 

million gallons (72,000 m3

) 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 

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. 

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

EPA 816-R-03-002 (EPA, 2003).
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-7 

Figure 2-2

36-inch CSC 301 purple mortar 

pipe, San Antonio Water System 

(Photo credit: Don Vandertulip)

 The amount of potable water to be saved that is 

not dependent on weather or climate conditions

 Other potential future users along each 

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

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 

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 

Antonio Water 

System (SAWS). 
Chapter 2 | Planning and Management Considerations

2-8 2012 Guidelines for Water Reuse

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. 

Figure 2-3 

Appropriate separation of potable, reclaimed water, and sanitary sewer pipes (FDEP, n.d.)

Location of Public Water System Mains in Accordance with F.A.C. Rule 62-555.314
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-9 

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. 

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 

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.

 

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 

Figure 2-4

Purple snap-on reclaimed water identification cap 

(Photo credit: Rain Bird)
Chapter 2 | Planning and Management Considerations

2-10 2012 Guidelines for Water Reuse

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 Production Wholesale Distribution Retail Distribution

Separate Authorities Wastewater Treatment Agency Wholesale Water Agency Retail Water Entity

Wholesaler/Retailer System Wastewater Treatment Agency Wastewater Treatment 

Agency Retail Water Entity

Joint Powers Authority (for 

Production and Distribution only) Joint Powers Authority Joint Powers Authority Retail Water Entity

Integrated Production and 

Distribution Water/Wastewater Authority Water/Wastewater 

Authority

Water/Wastewater 

Authority
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-11

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 

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 
Chapter 2 | Planning and Management Considerations

2-12 2012 Guidelines for Water Reuse

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 

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-13

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 

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, 
Chapter 2 | Planning and Management Considerations

2-14 2012 Guidelines for Water Reuse

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 

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-15

RECHARGE BASIN

Unconfined Aquifer

Aquitard

Confined Aquifer

Vadose Zone

VADOSE ZONE 

INJECTION WELL

DIRECT 

INJECTION 

WELL

Figure 2-5

Commonly used methods in managed aquifer recharge

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. 

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 

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.

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 

Figure 2-6

Sample decision tree for selection of groundwater 

recharge method

Is this aquifer 

confined or unconfined?

If Confined

Direct injection 

must be used.

If Unconfined

No constraint on 

recharge method.

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.
Chapter 2 | Planning and Management Considerations

2-16 2012 Guidelines for Water Reuse

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).

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-17

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.

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.
Chapter 2 | Planning and Management Considerations

2-18 2012 Guidelines for Water Reuse

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 

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 

Table 2-2 Comparison of vadose zone and direct injection recharge wells

Recharge Method Main Advantages Main Disadvantages

Vadose Zone Wells

- Suitable for unconfined aquifers

- Bypass low permeability layers

- Decreased travel time to aquifers versus 

surface spreading

- Lower cost

- SAT benefits to water quality

- May allow smaller setback from extraction 

wells

- 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

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

- Wells can be costly to install and 

maintain

- Periodic pumping required to maintain 

capacity

- Foot valves may be required to minimize 

air entrainment
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-19

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 

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 
Chapter 2 | Planning and Management Considerations

2-20 2012 Guidelines for Water Reuse

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 

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-21

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.

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).
Chapter 2 | Planning and Management Considerations

2-22 2012 Guidelines for Water Reuse

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 

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

Table 2-3 Operational status and source water treatment for reclaimed water ASR projects

State or Country City or County Operation Status Reclaimed Water Treatment Level

Arizona Chandler Full Operation Advanced treatment with UV disinfection

Arizona Fountain Hills Full Operation Conventional secondary treatment

/microfiltration/unknown method of disinfection

Arizona Scottsdale Full Operation Advanced treatment/microfiltration/RO/Cl2

disinfection

Florida Cocoa Testing Advanced treatment with Cl2 disinfection

Florida Englewood Full Operation Advanced treatment with Cl2 disinfection

Florida Hillsborough County Terminated NA

Florida Clearwater Terminated NA

Florida Lehigh Acres Testing Advanced treatment with Cl2 disinfection

Florida Manatee County Testing Advanced treatment with Cl2 disinfection

Florida Collier County Testing Advanced treatment with Cl2 disinfection

Florida Naples Testing Advanced treatment with Cl2 disinfection

Florida Oldsmar Permitting Advanced treatment with Cl2 disinfection

Florida Pinellas County Feasibility/Planning Advanced treatment with Cl2 disinfection

Florida St. Petersburg Testing Advanced treatment with Cl2 disinfection

Florida Tarpon Springs Feasibility/Planning Advanced treatment with Cl2 disinfection

Florida Sarasota County Construction Advanced treatment with Cl2 disinfection

Texas El Paso Full Operation Advanced treatment/ozone disinfection

Australia Adelaide (Bolivar) Full Operation Advanced treatment with Cl2 disinfection

Australia Willunga Testing Advanced treatment with Cl2 disinfection

Kuwait Sulaibiya Feasibility/Planning Advanced treatment/RO/unknown method of 

disinfection

(Source: Updated data from WRRF, 2007b) 

Cl2 means chlorine

NA means not applicable
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-23

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

 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 
Chapter 2 | Planning and Management Considerations

2-24 2012 Guidelines for Water Reuse

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.

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 all 

nonpotable components of the system

 Devise procedures for approval (and 

disconnection) of service

 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 

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. 

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.

Figure 2-7

Typical sign complying with FDEP signage 

requirements (Photo credit: Lisa Prieto)
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-25

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. 

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 

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 

Figure 2-8

Reclaimed water pumping station, San Antonio, 

Texas (Photo credit: Don Vandertulip)
Chapter 2 | Planning and Management Considerations

2-26 2012 Guidelines for Water Reuse

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? Examples

Monitoring 

frequency

Enterococci

(MPN/100mL)

Fecal Coliforms

or E. coli

(MPN/100mL)

CBOD5 

or

BOD5 

(mg/L)

Turbidity

(NTU)

Type I Yes

Irrigation, recreational 

impoundments, 

firefighting, toilet flush 

water

Twice weekly 9/41 75/201 5 3 

Type II No Restricted or remote 

reuse Once weekly 35 800/2001 15 or 202 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.
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-27

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 

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:
Chapter 2 | Planning and Management Considerations

2-28 2012 Guidelines for Water Reuse

 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 

between 1,500 and 100,000 gpd (5.6 to 380 m3

/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 

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.
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-29

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, 

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) 

Figure 2-9

Upper Occoquan schematic
Chapter 2 | Planning and Management Considerations

2-30 2012 Guidelines for Water Reuse

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 

water use rate ($0.85/1,000 gallons [$0.22/m3

] for the 

smallest meter size) that is slightly higher than existing 

reclaimed water use rates ($0.61/1,000 gallons 

[$0.16/m3

]). 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:

 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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-31

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. 

2.4.1 Water Conservation

Integrating water conservation goals and programs 

into utility water planning is emerging as a priority for 

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
Chapter 2 | Planning and Management Considerations

2-32 2012 Guidelines for Water Reuse

 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. 

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-33

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 

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 
Chapter 2 | Planning and Management Considerations

2-34 2012 Guidelines for Water Reuse

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 

gpd (5.7 m3

/d) or larger. The standards apply to 

graywater treatment systems having a rated treatment 

capacity of up to 1,500 gpd (5.7 m3

/d), residential 

wastewater treatment systems with treatment 

capacities up to 1,500 gpd (5.7 m3

/d), and commercial 

treatment systems with capacities exceeding 1,500 

gpd (5.7 m3

/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 

(5.7 m3

/d). For systems above 1,500 gpd (5.7 m3/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

Color MR1

Odor Non-offensive

Oily film and foam Non-detectable

Energy consumption MR

1 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

Parameter

Class R Class C

Test Average

Single Sample 

Maximum Test Average

Single Sample 

Maximum

CBOD5 (mg/L) 10 25 10 25

TSS (mg/L) 10 30 10 30

Turbidity (NTU) 5 10 2 5

E. coli 2

(MPN/100 mL) 14 240 2.2 200

pH (SU) 6.0 – 9.0 NA1 6.0 – 9.0 NA

Storage vessel disinfection

(mg/L)3 ≥ 0.5 – ≤ 2.5 NA ≥ 0.5 – ≤ 2.5 NA

Color MR4 NA MR NA

Odor Nonoffensive NA Nonoffensive NA

Oily film and foam Nondetectable Nondetectable Nondetectable Nondetectable

Energy consumption MR NA MR NA 1 NA: not applicable 2 Calculated as geometric mean 3 As total chlorine; other disinfectants can be used 4 MR: Measured reported only
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-35

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. 

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:
Chapter 2 | Planning and Management Considerations

2-36 2012 Guidelines for Water Reuse

 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 

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 

10 million ft2 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. 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-37

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 

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.
Chapter 2 | Planning and Management Considerations

2-38 2012 Guidelines for Water Reuse

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.

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 

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 
Chapter 2 | Planning and Management Considerations

2012 Guidelines for Water Reuse 2-39

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 

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 
Chapter 2 | Planning and Management Considerations

2-40 2012 Guidelines for Water Reuse

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.

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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.
2012 Guidelines for Water Reuse 3-1 

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.

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 

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.

Figure 3-1

Reclaimed water use in the United States

Approximately 7-8% 

reclaimed

The United States produces approximately 32 

billion gallons of municipal effluent per day.
Chapter 3 | Types of Reuse Applications

3-2 2012 Guidelines for Water Reuse

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 

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. 

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

Reuse Category

California

(% Use in 2009)

Florida

(% Use in 2010)

Irrigation 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 - 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-3 

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. 

In San Antonio, SAWS and Texas A&M University 

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 

Bermuda grass and Jamur zoysia grass 

(Thomas et al., 2006). The study evaluated 

leachate quality, soil ion retention, and grass 

quality. Of particular concern was the potential 

transport through the root zone of nitrate, 

which could potentially percolate in the local 

karst geology to the sole source Edwards 

Aquifer. Results indicated both grasses were 

well adapted to using the SAWS reclaimed 

water; the grasses maintained high quality but 

did not uptake all of the nitrogen applied during 

the December to February dormant period. Soil 

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

 Providing adequate drainage

Table 3-2 Interpretation of reclaimed water quality

Parameter Units

Degree of Restriction on Use

None

Slight to 

Moderate Severe

Salinity

Ecw dS m-1 < 0.7 0.7 - 3.0 > 3.0

TDS mg/L < 450 450 - 2,000 > 2,000

Ion Toxicity SAR < 3 3-9 > 9

Sodium (Na) meq/L < 3 > 3

Root Absorption mg/L < 70 > 70

Foliar Absorption meq/L < 2 2 - 10 > 10

Chloride (Cl) mg/L < 70 70 - 355 > 355

Root Absorption meq/L < 3 > 3

Foliar Absorption mg/L < 100 > 100

Boron mg/L < 1.0 1.0 - 2.0 > 2.0

pH 6.5 - 8.4
Chapter 3 | Types of Reuse Applications

3-4 2012 Guidelines for Water Reuse

 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 

1,000 ft2

). 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. 

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 

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.
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-5 

 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 

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)

State

Annual Agricultural Reuse 

Volume

mgd 1000 ac-ft/yr

Arizona 23 26

California 270 303

Colorado 2.97 3 

Florida 256 287

Idaho 0.27 0.3

North Carolina 1.0 1 

Nevada 13.4 15

Texas 19.4 22

Utah 0.81 1 

Washington 0.02 0.03

Wyoming 0.89 1 

Figure 3-2

Nationwide reuse summaries of reclaimed water use in agricultural irrigation (adapted from Bryk, et al., 2011)

29%

18% 20%

8%

7%

7%

5%

4% 2%

Agriculture Irrigation: 29%

Other: 20%

Landscape Irrigation/Golf Course Irrigation: 18%

Seawater Barrier: 8%

Commercial & Industrial: 7%

Recreational Impoundment: 7%

Groundwater Recharge: 5%

Natural System Restoration, Wetlands, Wildlife Habitat: 4%

Geothermal/Energy Production: 2%

Indirect Potable Reuse: 0% (not visible)

Surface Water Augmentation: 0% (not visible)
Chapter 3 | Types of Reuse Applications

3-6 2012 Guidelines for Water Reuse

3.2.1 Agricultural Reuse Standards

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. 

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.

3.2.2 Agricultural Reuse Water Quality

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.

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 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-7 

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 irrigation1

Potential Irrigation Problem Units

Degree of Restriction on Irrigation

None Slight to Moderate Severe

Salinity (affects crop water availability)2

ECw dS/m < 0.7 0.7 – 3.0 > 3.0

TDS mg/L < 450 450 – 2000 > 2000

Infiltration (affects infiltration rate of water into the soil; evaluate using ECw and SAR together)3

SAR 

0 – 3

and ECw = 

> 0.7 0.7 – 0.2 < 0.2

3 – 6 > 1.2 1.2 – 0.3 < 0.3

6 – 12 > 1.9 1.9 – 0.5 < 0.5

12 – 20 > 2.9 2.9 – 1.3 < 1.3

20 – 40 > 5.0 5.0 – 2.9 < 2.9

Specific Ion Toxicity (affects sensitive crops)

Sodium (Na)4

surface irrigation SAR < 3 3 – 9 > 9

sprinkler irrigation meq/l < 3 > 3

Chloride (Cl)4

surface irrigation meq/l < 4 4 – 10 > 10

sprinkler irrigation meq/l < 3 > 3

Boron (B) mg/L < 0.7 0.7 – 3.0 > 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

pH Normal Range 6.5 – 8.4 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. 
Chapter 3 | Types of Reuse Applications

3-8 2012 Guidelines for Water Reuse

 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 

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.
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-9 

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) Remarks

Aluminum 5.0 Can cause nonproductiveness in acid soils, but soils at pH 5.5 to 8.0 will precipitate 

the ion and eliminate toxicity

Arsenic 0.10 Toxicity to plants varies widely, ranging from 12 mg/L for Sudan grass to less than 

0.05 mg/L for rice

Beryllium 0.10 Toxicity to plants varies widely, ranging from 5 mg/L for kale to 0.5 mg/L for bush 

beans

Boron 0.75

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

Cadmium 0.01 Toxic to beans, beets, and turnips at concentrations as low as 0.1 mg/L; conservative 

limits are recommended

Chromium 0.1 Not generally recognized as an essential element; due to lack of toxicity data, 

conservative limits are recommended

Cobalt 0.05 Toxic to tomatoes at 0.1 mg/L; tends to be inactivated by neutral and alkaline soils

Copper 0.2 Toxic to a number of plants at 0.1 to 1.0 mg/L

Fluoride 1.0 Inactivated by neutral and alkaline soils

Iron 5.0 Not toxic in aerated soils, but can contribute to soil acidification and loss of 

phosphorus and molybdenum

Lead 5.0 Can inhibit plant cell growth at very high concentrations

Lithium 2.5 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

Manganese 0.2 Toxic to a number of crops at few-tenths to few mg/L in acidic soils

Molybdenum 0.01 Nontoxic to plants; can be toxic to livestock if forage is grown in soils with high 

molybdenum

Nickel 0.2 Toxic to a number of plants at 0.5 to 1.0 mg/L; reduced toxicity at neutral or alkaline 

pH

Selenium 0.02 Toxic to plants at low concentrations and to livestock if forage is grown in soils with 

low levels of selenium

Tin, Tungsten, 

and Titanium - Excluded by plants; specific tolerance levels unknown

Vanadium 0.1 Toxic to many plants at relatively low concentrations

Zinc 2.0 Toxic to many plants at widely varying concentrations; reduced toxicity at increased 

pH (6 or above) and in fine-textured or organic soils
Chapter 3 | Types of Reuse Applications

3-10 2012 Guidelines for Water Reuse

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]. 

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 

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.

3.2.3 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 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-11

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, 11-

year 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.

The success of this exemplary and pioneering project 

in Monterey County—from both technical and public 

acceptance points of view—has encouraged similar 

projects in other parts of the United States. and 

throughout the world [US-CA-Temecula, US-WA-King 

County, Argentina-Mendoza, Israel/Palestinian 

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. 
Chapter 3 | Types of Reuse Applications

3-12 2012 Guidelines for Water Reuse

Figure 3-4

Alfalfa irrigated with secondary effluent, Wadi Mousa (near Petra), Jordan

Figure 3-3

Monterey County vegetable fields irrigated with disinfected tertiary recycled water
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-13

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

Microbial Standards or 

Guidelines by 

State, Country, Region

Total 

Coliform

per 100 mL

Fecal 

Coliform 

or 

E. coli per 

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.

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 

(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 

in livestock drinking water1

Constituent (Symbol) Concentration 

(mg/L)

Aluminium (Al) 5.0

Arsenic (As) 0.2

Beryllium (Be)2 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

Lead (Pb)3 0.1

Manganese (Mn)4 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

Sodium (Na) 10005

Sulfate (as SO4) 10006

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.
Chapter 3 | Types of Reuse Applications

3-14 2012 Guidelines for Water Reuse

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. 

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.
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-15

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.

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 

snowmelt. An ac-ft (1,200 m3

) of medium-density snow 

(1 ac with 1 ft of snow on it) has an equivalent water 

volume of approximately 146,000 gallons (550 m3

). 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.

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) 

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.

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).

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 
Chapter 3 | Types of Reuse Applications

3-16 2012 Guidelines for Water Reuse

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 

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 

of 100 mJ/cm2 under maximum daily flow should be 

used. The design dose may be reduced to 80 mJ/cm2

for porous membrane filtration and 50 mJ/cm2 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. 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-17

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, 

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.

 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 
Chapter 3 | Types of Reuse Applications

3-18 2012 Guidelines for Water Reuse

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 

grasslands, and 1,800 ft2 (170 m2

) 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 

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. 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-19

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. 

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 
Chapter 3 | Types of Reuse Applications

3-20 2012 Guidelines for Water Reuse

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.

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 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-21

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. 

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 

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.

Figure 3-5

Large hyperbolic cooling towers (Photo Courtesy of International Cooling Towers)
Chapter 3 | Types of Reuse Applications

3-22 2012 Guidelines for Water Reuse

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 

Pressure (psig) 0-300 301-450 451-600 601-750 751-900

901-

1000

1001-

1500

1501-

2000 OTSG

Steam 

TDS max 

(ppm) 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

Boiler Water

TDS max 

(ppm) 700-3500 600-3000

500-

2500

200-

1000 150-750 125-625 100 50 0.05

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 

(μmho/cm) 

1100-

5400

900-

4600

800-

3800

300-

1500

200-

1200

200-

1000 150 80 0.15-

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 

(ppm O2) 0.007 0.007 0.007 0.007 0.007 0.007 0.007 0.007 n/a

Total Iron 

(ppm Fe) 0.1 0.05 0.03 0.025 0.02 0.02 0.01 0.01 0.01

Total Copper (ppm Cu) 0.05 0.025 0.02 0.02 0.015 0.01 0.01 0.01 0.002

Total Hardness 

(ppm CaCO3) 0.3 0.3 0.2 0.2 0.1 0.05 ND ND ND

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 

(ppm C) 1 1 0.5 0.5 0.5 0.2 0.2 0.2 ND

Oily Matter 

(ppm) 1 1 0.5 0.5 0.5 0.2 0.2 0.2 ND

Source: Boiler Water Quality Requirements and Associated Steam Quality for Industrial/Commercial and Institutional Boilers 

(American Boiler Manufacturers Association, 2005)
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-23

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.). 

Figure 3-6

Estimates of produced water by state (GWI, 2011) 

Texas 35%

California 12%

Wyoming 11%

Oklahoma 11%

Kansas 6%

Louisiana 5%

Other States 

20%

69.8 billion bbl/yr

Worldwide produced

water volume

20.7 billion 

bbl/yr

U.S. produced

water volume

(2007)
Chapter 3 | Types of Reuse Applications

3-24 2012 Guidelines for Water Reuse

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. 

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. 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-25

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 

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).
Chapter 3 | Types of Reuse Applications

3-26 2012 Guidelines for Water Reuse

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 

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 
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-27

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 

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). 
Chapter 3 | Types of Reuse Applications

3-28 2012 Guidelines for Water Reuse

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).

3.7.1 Planned Indirect Potable Reuse (IPR) 

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 

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 and yield of alternate 

sources

 High cost of developing alternate water sources

 Conscious or unconscious public acceptance

 Confidence in, and some level of control over, 

both advanced reclaimed water treatment 

processes and water treatment processes

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 

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)

Description of Advanced System for 

Potable Reuse Case Study

Belgium Wulpen 1.9 Reclaimed water is returned to the aquifer 

before being reused as a potable water source [Belgium-Recharge] 

India Bangalore 

(planned) 36

Reclaimed water will be blended in the 

reservoir, which is a major drinking water 

source

[India-Bangalore]

Namibia Windhoek 5.5

Reclaimed water is blended with 

conventionally-treated surface water for 

potable reuse

(NAS, 2012)

United States Big Spring, 

Texas 3 Reclaimed water is blended with raw surface 

water for potable reuse [US-TX-Big Spring]

United States

Upper 

Occoquan, 

Virginia

54 Reclaimed water is blended in the reservoir, 

which is a major drinking water source [US-VA-Occoquan]

United States Orange County, 

California 40 Reclaimed water is returned to the aquifer 

before being reused as a potable water source [US-CA-Orange County] 

United 

Kingdom Langford 10.5 Reclaimed water is returned upstream to a river, which is the potable water source

[United KingdomLangford]

Singapore Singapore 122 Reclaimed water is blended in the reservoir, 

which is a major drinking water source [Singapore-NEWater]

South Africa Malahleni 4.2 Reclaimed water from a mine is supplied as 

drinking water to the municipality

[South Africa-eMalahleni

Mine]

Source: Adapted from Von Sperling and Chernicharo (2002)
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-29

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 

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 

Figure 3-7

Planned IPR scenarios and examples
Chapter 3 | Types of Reuse Applications

3-30 2012 Guidelines for Water Reuse

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 

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.
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-31

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 

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 

Figure 3-8

Planned DPR and specific examples of implementation
Chapter 3 | Types of Reuse Applications

3-32 2012 Guidelines for Water Reuse

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. 

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
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-33

 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

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Water Quality Requirements and Associated Steam Quality 

for Industrial/Commercial and Institutional Boilers. ABMA. 

Vienna, VA. 

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Orleans Plans to Restore Wetlands Using Effluent Have 

‘Wow’ Factors.” Streamlines. 2(24).

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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. 

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Baydal, D. 2009. “Municipal Wastewater Recycling Survey.” 

California Water Recycling Funding Program (WRFP). 

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<http://www.swrcb.ca.gov/water_issues/programs/grants_loa

ns/water_recycling/munirec.shtml>

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 

<http://www.cdph.ca.gov/certlic/drinkingwater/Documents/La

wbook/RWregulations-01-2009.pdf>. 

California State Water Resources Control Board (California 

SWRCB). 2009. Recycled Water Policy. Retrieved July 

2012, from 

<http://www.swrcb.ca.gov/water_issues/programs/water_rec

ycling_policy/>

Cirelli, G. L., S. Consoli, F. Licciardello, R. Aiello, F. 

Giuffrida, and C. Leonardi. 2012. Treated Municipal 

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

<http://www.evs.anl.gov/pub/dsp_detail.cfm?PubID=2437>. 

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 

<http://www.dep.state.fl.us/water/reuse/inventory.htm>. 

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.
Chapter 3 | Types of Reuse Applications

3-34 2012 Guidelines for Water Reuse

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 

<http://www.gcsaa.org/Course/Environment/default.aspx>. 

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 

<http://pubs.usgs.gov/circ/1344/pdf/c1344.pdf>. 

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).

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(4-

5):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.
Chapter 3 | Types of Reuse Applications

2012 Guidelines for Water Reuse 3-35

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.

U.S. Department of Energy (DOE). n.d. Produced Water 

Management Information System. Retrieved on September 

5, 2012, from 

<http://www.netl.doe.gov/technologies/pwmis/>. 

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 

<http://water.epa.gov/grants_funding/cwsrf/upload/AlbanyMillersburg-Case-Study.pdf>. 

U.S. Environmental Protection Agency (EPA). 2011. Draft 

Recreational Water Quality Criteria 820-D-11-002. 

Retrieved August 2012, from 

<http://water.epa.gov/scitech/swguidance/standards/criteria/

health/recreation/upload/recreation_document_draft.pdf>. 

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 

and Standards for Potable Reuse and Feasible Alternatives.

EPA 570/9-82-005. Environmental Protection Agency. 

Washington, D.C.

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.

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.

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-06-

018-1A. 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 4-1 

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 

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. 
Chapter 4 | State Regulatory Programs for Water Reuse

4-2 2012 Guidelines for Water Reuse

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

Factor Description

1 Establish the objectives Objectives that encourage and promote reuse should be clear and concise. 

2 Commit to the long run A water reuse program should be considered a permanent, high-priority program within the state. 

3 Identify the lead agency or 

agencies

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.

4 Identify water reuse leader 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.

5 Enact needed legislation 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.

6 Adopt and implement rules 

or guidelines governing 

water reuse

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.

7 Be proactive 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. 

8 Develop and cultivate 

needed partnerships

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.

9 Ensure the safety of water 

reuse

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).

10 Develop specific program 

components

Program components are going to differ from state to state and maturity of the reuse program.

11 Focus on quality, integrity, 

and service

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.

12 Be consistent 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.

13 Promote a water reuse 

community

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.

14 Maintain a reuse inventory 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.

15 Address cross-connection 

control issues

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).
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-3 

Table 4-2 Fundamental components of a water reuse regulatory framework for states

Category Comment

Purpose and/or goal 

statement

 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.

Definitions  Define type of use and other water reuse-related terms used within the body of the rule or regulation.

Scope and applicability

 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.

Exclusions and 

prohibitions

 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.

Variances

 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.

Permitting requirements

 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.

Define or refine control 

and access to reclaimed 

water

 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.

Relationship to other 

rules 

 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.

Relationship to 

stakeholders 

 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.

Relationship to 

regulations or guidelines 

for uses of other nonconventional water 

sources

 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.

Reclaimed water 

standards 

 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).

Treatment technology 

requirements  In addition to reclaimed water standards, some states specify treatment technologies for specific reuse applications.

Monitoring requirements  Describe methods and frequency for monitoring all standards listed in the rules or regulations.

Criteria or standards for 

design, siting, and 

construction

 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).
Chapter 4 | State Regulatory Programs for Water Reuse

4-4 2012 Guidelines for Water Reuse

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 

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 

Table 4-2 Fundamental components of a water reuse regulatory framework for states (cont.) 

Category Comment

Construction requirements  Describe requirements for engineering reports, pilot studies, and certificates required to construct and to operate.

Operations and maintenance 

(O&M)

 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.

Management of pollutants from 

significant industrial users as 

source water protection

 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. 

Access control and use area 

requirements

 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.).

Education and notification

 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.

Operational flow requirements  Requirements for maintaining flow within design capacity of treatment system or planning for additional treatment 

capacity as needed.

Contingency plan  Include a requirement for a contingency plan that describes how system failures, unauthorized discharges, or 

upsets will be remedied or addressed.

Recordkeeping  Describe what operating records must be maintained, the location where they are retained, and the minimum 

period of retention.

Reporting  Describe what items must be reported, the frequency of reporting, and to whom they are reported.

Stakeholder participation  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.

Financial assistance  Describe state, local, or federal funding or financing sources.
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-5 

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, 

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 
Chapter 4 | State Regulatory Programs for Water Reuse

4-6 2012 Guidelines 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 

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.
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-7 

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). 

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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4-8 2012 Guidelines for Water Reuse

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

categories 1

Category of reuse Description

Number of States

or Territories with 

Rules, 

Regulations, or 

Guidelines 

Addressing

Reuse Category

Urban Reuse

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

Agricultural 

Reuse

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

Impoundments

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

Potable Reuse

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 

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
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-9 

Table 4-4 Suggested guidelines for water reuse

Reuse Category and 

Description Treatment Reclaimed Water Quality 2 Reclaimed Water Monitoring Setback Distances 3 Comments

Urban Reuse

The use of reclaimed water in 

nonpotable applications in municipal 

settings where public access is not 

restricted. 

Unrestricted  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.

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

Restricted 

 Secondary (4)

 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.

Agricultural Reuse

The use of reclaimed water for 

surface or spray irrigation of food 

crops which are intended for human 

consumption, consumed raw.

Food Crops 15

 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)

 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.

The use of reclaimed water for 

surface irrigation of food crops which 

are intended for human consumption, 

commercially processed. 

Processed Food Crops 15

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.

Non-Food Crops  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

 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.
Chapter 4 | State Regulatory Programs for Water Reuse

4-10 2012 Guidelines 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

The use of reclaimed water in an 

impoundment in which no limitations 

are imposed on body-contact.

Unrestricted  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

 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.

The use of reclaimed water in an 

impoundment where body-contact is 

restricted.

Restricted

 Secondary (4)

 Disinfection (6)

 ≤ 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

 500 ft (150 m) to potable water supply wells 

(min.) if bottom not sealed

 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

The use of reclaimed water to create 

wetlands, enhance natural wetlands, 

or sustain stream flows.

Environmental Reuse  Variable

 Secondary (4) and 

disinfection (6) (min.)

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

 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

 Secondary Once-through Cooling (4)

 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 – weekly

 Fecal coliform - daily

 Cl2 residual – continuous

 300 ft (90 m) to areas accessible to the 

public  Windblown spray should not reach areas accessible to workers or the public.

 Secondary (4)

Recirculating Cooling Towers  Disinfection (6)(chemical coagulation 

and filtration (5) may be 

needed)

Variable, depends on recirculation ratio: 

 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)

 300 ft (90 m) to areas accessible to the 

public. May be reduced if high level of 

disinfection is provided.

 Windblown spray should not reach areas accessible to workers or the public.

 Additional treatment by user is usually provided to prevent scaling, corrosion, biological growths, fouling and 

foaming.

 See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.

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.

 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.
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-11

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

 Secondary (4)

 Filtration (5)

 Disinfection (6)

 Soil aquifer treatment

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:

 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

 Distance to nearest potable water extraction 

well that provides a minimum of 2 months 

retention time in the underground.

 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.

Groundwater Recharge by 

Injection into Potable Aquifers

 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

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.

 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.

Augmentation of Surface Water 

Supply Reservoirs

 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

 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.

 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.
Chapter 4 | State Regulatory Programs for Water Reuse

4-12 2012 Guidelines 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:

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.

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.

3. There have been minor changes to the names of 

the reuse categories as follows:

a. “Urban reuse” is now “Urban Reuse – 

Unrestricted” 

b. “”Restricted access irrigation” is now “Urban 

Reuse – Restricted”

c. “Recreational impoundments” is now 

“Impoundments – Unrestricted”

d. “Landscape impoundments” is now 

“Impoundments – Restricted” 

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 
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-13

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. 

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 

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. 
Chapter 4 | State Regulatory Programs for Water Reuse

4-14 2012 Guidelines 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 

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 
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-15

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 

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)
Chapter 4 | State Regulatory Programs for Water Reuse

4-16 2012 Guidelines 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 

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 
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-17

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. 

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 

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 

<https://www.watereuse.org/governmentaffairs/usepa-guidelines>. 

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. 
Chapter 4 | State Regulatory Programs for Water Reuse

4-18 2012 Guidelines for Water Reuse

Table 4-5 Summary of State and U.S. Territory water reuse regulations and guidelines*

The intent of the state’s regulations or guidelines is oversight of water reuse 

The intent of the state’s regulations or guidelines is oversight of disposal and water reuse is considered incidental

-- The state does not have water reuse regulations or guidelines but may permit reuse on a case-by-case basis.

State 

RegulationsGuidelinesNo Regulations or Guidelines (1)Change from 2004 Edition Urban Reuse – UnrestrictedUrban Reuse – RestrictedAgricultural Reuse 

–

Food CropsAgricultural Reuse – Processed Food Crops and Non-Food CropsImpoundments 

–

UnrestrictedImpoundments 

–

RestrictedEnvironmental ReuseIndustrial ReuseGroundwater Recharge

–

Nonpotable ReuseIndirect Potable Reuse

Alabama   

Alaska  

Arizona  Update         

Arkansas  New (2) 

California  Update         

Colorado    

Commonwealth 

of the Northern 

Mariana Islands 

(CNMI)

 (3)  

Connecticut --

Delaware  Update        

District of 

Columbia --

Florida  Update        

Georgia  Update   

Guam (4)

Hawaii         

Idaho  Update      

Illinois    

Indiana  Update    

Iowa   

Kansas      

Kentucky --

Louisiana -- 
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-19

Table 4-5 Summary of State and U.S. Territory reuse regulations and guidelines* 

The state’s regulations or guidelines intent is for the oversight of water reuse 

The state’s regulations or guidelines intent is for the oversight of disposal and water reuse is incidental

-- The state does not have water reuse regulations or guidelines but may permit reuse on a case-by-case basis.

State 

RegulationsGuidelinesNo Regulations or Guidelines (1)Change from 2004 Edition Urban Reuse – UnrestrictedUrban Reuse – RestrictedAgricultural Reuse 

–

Food CropsAgricultural Reuse – Processed Food Crops and Non-Food CropsImpoundments 

–

UnrestrictedImpoundments 

–

RestrictedEnvironmental ReuseIndustrial ReuseGroundwater Recharge

–

Nonpotable ReuseIndirect Potable Reuse

Maine --

Maryland  Update      

Massachusetts  New (2)          

Michigan   

Minnesota  (5)      

Mississippi    

Missouri      

Montana  Update (6)        

Nebraska  Update        

Nevada  Update      

New Hampshire --

New Jersey   New (7)     

New Mexico  Update (8)       

New York -- (9) 

North Carolina  Update      

North Dakota  Update       

Ohio    

Oklahoma  Update    

Oregon  Update (10)        

Pennsylvania          

Rhode Island  New (11)    

South Carolina    

South Dakota  Update     
Chapter 4 | State Regulatory Programs for Water Reuse

4-20 2012 Guidelines for Water Reuse

Table 4-5 Summary of State and U.S. Territory reuse regulations and guidelines*

The state’s regulations or guidelines intent is for the oversight of water reuse 

The state’s regulations or guidelines intent is for the oversight of disposal and water reuse is incidental

-- The state does not have water reuse regulations or guidelines but may permit reuse on a case-by-case basis.

State 

RegulationsGuidelinesNo Regulations or Guidelines (1)Change from 2004 Edition Urban Reuse – UnrestrictedUrban Reuse – RestrictedAgricultural Reuse 

–

Food CropsAgricultural Reuse – Processed Food Crops and Non-Food CropsImpoundments 

–

UnrestrictedImpoundments 

–

RestrictedEnvironmental ReuseIndustrial ReuseGroundwater Recharge

–

Nonpotable ReuseIndirect Potable Reuse

Tennessee  Update (12)       

Texas  Update        

Utah        

Vermont   

Virginia  New (13)          

Washington  Update (14)          

West Virginia  (15)  

Wisconsin  Update    

Wyoming  Update     

(1) Specific regulations or guidelines on reuse not adopted; however, reuse may be approved on a case-by-case basis

(2) The state had guidelines prior, and now has adopted regulations.

(3) CNMI regulations were not listed in the 2004 guidelines. 

(4) 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.
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-21

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 

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.
Chapter 4 | State Regulatory Programs for Water Reuse

4-22 2012 Guidelines 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 

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.
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-23

Table 4-6 Abbreviations of terms for state reuse rules 

descriptions

Term Abbreviation

Annual ann

Average avg

Corrective action threshold CAT

Day d 

Geometric mean geom

Hour hr

Maximum max

Median med

Minimum min

Month mon

UV dose requirements including:

• 100 mJ/cm2 for media filtration

• 80 mJ/cm2 for membrane filtration

• 50 mJ/cm2 for RO treatment

There are additional requirements for 

bioassay validation and UV system 

design considerations

NWRI UV 

Guidelines*

Product of the total residual chlorine and 

contact time

CrT**

Total residual chlorine TRC

Week wk

Year 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 

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 
Chapter 4 | State Regulatory Programs for Water Reuse

4-24 2012 Guidelines 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

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.

4.5.2.5 Impoundments – Unrestricted

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 

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.

4.5.2.7 Environmental Reuse 

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.

4.5.2.8 Industrial 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.
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-25

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, 

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.
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-26

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.

Table 4-7 Urban reuse – unrestricted

Arizona

Class A

California

Disinfected Tertiary Florida

Hawaii

R1 Water

Nevada

Category A

New Jersey

Type I RWBR

North Carolina

Type 1

Texas

Type I

Virginia

Level 1

Washington

Class A

Treatment (System Design) 

Requirements

Unit processes Secondary treatment, 

filtration, disinfection

Oxidized, coagulated, 

filtered, disinfected

Secondary treatment, 

filtration, high-level 

disinfection

Oxidized, filtered, 

disinfected

Secondary treatment, 

disinfection

Filtration, high-level 

disinfection

Filtration 

(or equivalent) NS

Secondary treatment, 

filtration, high-level 

disinfection

Oxidized, coagulated, 

filtered, disinfected

UV dose, 

if UV disinfection used NS NWRI UV Guidelines NWRI UV Guidelines

enforced, variance allowed NWRI UV Guidelines NS 100 mJ/cm2 

at max day flow NS NS NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used 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 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

Monitored Reclaimed Water Quality Requirements

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)

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

10 mg/L (mon avg)

or CBOD5: 

8 mg/L (mon avg)

30 mg/L

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

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)

Bacterial indicators

Fecal coliform: 

-none detectable in

last 4 of 7 samples

-23/100mL (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)

Fecal coliform: 

-75% of samples below 

detection

-25/100mL (max)

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)

Fecal coliform: 

-2.2/100mL (wk med)

-14/100mL (max)

Fecal coliform or E. coli: 

-14/100mL (mon mean) 

-25/100mL (max)

Fecal coliform or E. coli:

-20/100mL (30-d geom)

-75/100mL (max)

Enterococci: 

-4/100mL (30-d geom)

-9/100mL (max)

Fecal coliform: 

-14/100mL (mon geom),

CAT > 49/100mL

E. coli: 

-11/100mL (mon geom),

CAT > 35/100mL

Enterococci: 

-11/100mL (mon geom),

CAT > 24/100mL

Total coliform

-2.2/100mL (7-d med)

-23/100mL (max)

Pathogens NS NS

Giardia and Cryptosporidium

sampling once each 2-yr 

period for plants ≥1 mgd; 

once each 5-yr period for

plants ≤ 1 mgd

TR TR NS NS NS NS NS

Other

If nitrogen > 10 mg/L, 

special requirements 

may be mandated to 

protect groundwater

- - - - (NH3-N + NO3-N) 

< 10 mg/L (max)

Ammonia as NH3-N: 

-4 mg/L (mon avg)

-6 mg/L (daily max)

- - 

Specific reliability or 

redundancy requirements 

based on formal reliability 

assessment
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-27

NS = not specified by the state reuse regulation

1 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. 2 There is no expressed designation between unrestricted and restricted urban reuse in North Carolina regulations. 

Table 4-8 Urban reuse – restricted

Arizona

Class B

California

Disinfected 

Secondary-23 Florida1 HawaiiR2 Water

Nevada

Category B

New Jersey

Type II RWBR

North Carolina2 

Type 1

Texas

Type II

Virginia

Level 2

Washington

Class C

Treatment (System 

Design) Requirements

Unit processes Secondary treatment, 

disinfection Oxidized, disinfected NS Oxidized, disinfected Secondary treatment, 

disinfection Case-by-case

Filtration

(or equivalent) NS Secondary treatment, 

disinfection Oxidized, disinfected

UV dose, 

if UV disinfection used NS NS NS NS NS 75 mJ/cm2at max day flow NS NS NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used NS NS 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 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

Monitored Reclaimed Water Quality Requirements

BOD5

(CBOD for Florida) NS NS NS 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)

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)

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)

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-day geom) 

-89/100mL (max)

Fecal coliform: 

-200/100mL (mon geom),

CAT > 800/100mL

E. coli:

-126/100mL (mon geom), 

CAT > 235/100mL

Enterococci: 

-35/100mL (mon geom), 

CAT > 104/100mL

Total coliform: 

-23/100mL (7-d med)

-240/100mL (max)

Other

If nitrogen > 10 mg/L, 

special requirements 

may be mandated to 

protect groundwater

- - - - (NH3-N + NO3-N): 

< 10 mg/L (max)

Ammonia as NH3-N: 

-4 mg/L (mon avg)

-6 mg/L (daily max)

- - - 
Chapter 4 | State Regulatory Programs for Water Reuse

4-28 2012 Guidelines for Water Reuse

Table 4-9 Agricultural reuse - food crops

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 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. 2 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. 3

 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.

Arizona

Class A

California

Disinfected Tertiary Florida1 HawaiiR1 Water Nevada

New Jersey

Type III RWBR

North Carolina Texas1

Type I Reclaimed 

Water

Virginia3 

Level 1

Washington

Class A

Processed

Type 1

NOT processed

Type 2

Treatment (System 

Design) Requirements

Unit processes

Secondary 

treatment, filtration, 

disinfection

Oxidized, coagulated, 

filtered, disinfected

Secondary treatment, 

filtration, high-level 

disinfection

Oxidized, filtered, 

disinfected NP Filtration, high-level 

disinfection

Filtration

(or equivalent)

Filtration, dual 

UV/chlorination

(or equivalent)

NS 

Secondary treatment, 

filtration, high-level 

disinfection

Oxidized, coagulated, filtered, 

disinfected

UV dose, 

if UV disinfection used NS NWRI UV Guidelines

NWRI UV Guidelines 

enforced, variance 

allowed

NWRI UV Guidelines NP 100 mJ/cm2

at max day flow NS dual UV/chlorination

(or equivalent) NS NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used 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

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

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

Monitored Reclaimed Water Quality Requirements

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)

30 mg/L or 60 mg/L 

depending on design flow NP NS -10 mg/L (mon avg)

-15 mg/L (daily max)

-5 mg/L (mon avg)

-10 mg/L (daily max) 5 mg/L

10 mg/L (mon avg)

or CBOD5

8 mg/L (mon avg)

30 mg/L

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

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) 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)

Bacterial indicators

Fecal coliform:

-none detectable in 

last 4 of 7 samples

-23/100mL (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)

Fecal coliform:

-75% of samples

below detection

-25/100mL (max)

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 

Fecal coliform:

-2.2/100mL (wk med)

-14/100mL (max)

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)

Fecal coliform or E. coli:

-20/100mL (30-d geom)

-75/100mL (max)

Enterococci:

-4/100mL (30-d geom)

-9/100mL (max)

Fecal coliform:

 -14/100mL (mon geom),

CAT > 49/100mL

E. coli:

-11/100mL (mon geom), CAT 

> 35/100mL

Enterococci:

-11/100mL (mon geom),

CAT > 24/100mL

Total coliform:

-2.2/100mL ( 7-d med)

-23/100mL (max)

Viral indicators NS NS NS TR NP NS NS 

Coliphage:

- 5/100mL (mon mean)

- 25/100mL (daily max)

NS NS NS 

Pathogens 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 

Other

If nitrogen > 10 mg/L, 

special requirements 

may be mandated to 

protect groundwater

- - Oxidized, filtered, 

disinfected - 

(NH3-N + NO3-N):

< 10mg/L (max)

Special information, crop 

tests may be required

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
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-29

Table 4-10 Agricultural reuse – non-food crops and processed food crops (where permitted)

NS = not specified by the state’s reuse regulation

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. 2 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).

Arizona California

Undisinfected

Secondary Florida

Hawaii

R2 Water

Nevada2 

Category E

New Jersey

Type II RWBR

North Carolina

Type 1

Texas

Type II

Virginia

Level 2

Washington

Class B Class C Class C

Treatment (System 

Design) Requirements

Unit processes

Secondary 

treatment, 

disinfection

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

UV dose, 

if UV disinfection used NS NS NS NS NS NS 75 mJ/cm2at max day flow NS NS NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used NS NS 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 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

Monitored Reclaimed Water Quality Requirements

BOD5

(or CBOD5) NS NS 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 -10 mg/L (mon avg)

-15 mg/L (daily max)

Without pond: 20 mg/L

(or CBOD5 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

-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 -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 NS 10 NTU (max) NS NS NS

Bacterial indicators

Fecal coliform: 

-200/100mL in last 4 

of 7 samples

-800/100mL (max)

Fecal coliform: 

-1000/100mL in last

4 of 7 samples

-4000/100mL (max)

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

Fecal coliform: 

-200/100mL (mon geom)

-400/100mL (wk geom)

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)

Fecal coliform: 

-200/100mL (mon geom),

CAT > 800/100mL

E. coli:

-126/100mL (mon geom),

CAT > 235/100mL

Enterococci: 

-35/100mL (mon geom), 

CAT > 104/100mL

Total coliform: 

-23/100mL (7-d med)

-240/100mL (max)

Other

If nitrogen > 10 mg/L, 

special requirements 

may be mandated to 

protect groundwater

If nitrogen > 10 mg/L, 

special requirements 

may be mandated to 

protect groundwater

- - - - (NH3-N + NO3-N): 

< 10 mg/L (max)

Ammonia as NH3-N: 

-4 mg/L (mon avg)

-6 mg/L (daily max)

- - - 
Chapter 4 | State Regulatory Programs for Water Reuse

4-30 2012 Guidelines for Water Reuse

Table 4-11 Impoundments – unrestricted

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 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. 2 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.

Arizona1

Class A

California

Disinfected Tertiary Florida Hawaii Nevada New Jersey North Carolina

Texas

Type I

Virginia

Level 1

Washington

Class A

Treatment (System Design) 

Requirements

Unit processes Secondary treatment, 

disinfection

Oxidized, coagulated, 

filtered, disinfected2 NR NR NP NR NS NS

Secondary treatment, 

filtration, high-level 

disinfection

Oxidized, coagulated, 

filtered and disinfected

UV dose, 

if UV disinfection used NS NWRI UV Guidelines NR NR NP NR NS NS NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used NS

CrT > 450 mg·min/L; 

90 minutes modal 

contact time at peak 

dry weather flow

NR NR NP NR NS 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

Monitored Reclaimed Water Quality Requirements

BOD5 NS NS NR NR NP NR NS 5 mg/L

10 mg/L (mon avg)

or CBOD5: 

8 mg/L (mon avg)

30 mg/L

TSS NS NS NR NR NP NR NS NS NS 30 mg/L

Turbidity 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)

Bacterial indicators

Fecal coliform: 

-none detectable in last 

4 of 7 samples

-23/100mL (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 NR NP NR NS

Fecal coliform or E.coli:

-20/100mL (avg)

-75/100mL (max)

Enterococci:

-4/100mL (avg)

-9/100mL (max)

Fecal coliform:

-14/100mL (mon geom),

CAT > 49/100mL

E. coli: 

-11/100mL (mon geom),

CAT > 35/100mL

Enterococci:

-11/100mL (mon geom),

CAT > 24/100mL

Total coliform: 

-2.2/100mL (7-day med)

-23/100mL (max)

Other

If nitrogen > 10 mg/L, 

special requirements 

may be mandated to 

protect groundwater

Supplemental pathogen 

monitoring - - NP NR - - - 

Specific reliability 

and redundancy 

requirements based on 

formal assessment
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-31

Table 4-12 Impoundments – restricted

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

Arizona

Class B

California

Disinfected 

Secondary-2.2 Florida

Hawaii

R-2 Water

Nevada

Category A New Jersey North Carolina

Texas

Type II

Virginia

Level 2

Washington

Class B

Treatment (System Design) 

Requirements

Unit processes Secondary treatment, 

disinfection Oxidized, disinfected NR Oxidized, disinfected Secondary treatment, 

disinfection NR NS NS Secondary treatment, 

disinfection Oxidized, disinfected

UV dose, 

if UV disinfection used NS NS NR NS NS NR NS NS NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used NS NS NR

Chlorine residual > 5 mg/L; 

actual modal contact time of 

10 minutes

NS NR NS 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

Monitored Reclaimed Water Quality Requirements

BOD5 NS NS NR 30 mg/L or 60 mg/L 

depending on design flow 30 mg/L (30-d avg) NR NS

Without pond: 20 mg/L

(or CBOD5 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 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

Fecal coliform: 

-200/100mL in last 4 of 

7 samples

-800/100mL (max)

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)

NR NS

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

Enterococci: 

-35/100mL (mon 

geom), CAT > 

104/100mL

Total coliform: 

-2.2/100mL (7-d med)

-23/100mL (max)

Other

If nitrogen > 10 mg/L, 

special requirements 

may be mandated to 

protect groundwater

- - - - NR - - -

Specific reliability 

and redundancy 

requirements based on 

formal assessment
Chapter 4 | State Regulatory Programs for Water Reuse

4-32 2012 Guidelines for Water Reuse

Table 4-13 Environmental reuse 

NS = not specified by the state’s reuse regulation; NR = not regulated by the state under the reuse program

1 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." 2 Florida requirements are for a natural receiving wetland regulated under Florida Administrative Code Chapter 62-611 for Wetlands Application. 3 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. 4 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. 5 These limits are not to be exceeded unless net environmental benefits are provided by exceeding these limits. 6 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.

Arizona1 California Florida2 Hawaii

Nevada

Category C New Jersey

North Carolina

Type 1 Texas Virginia4 WashingtonClass A

Treatment (System Design) 

Requirements

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

TRC > 0.5 mg/L; 15 

minutes contact time at 

peak hr flow3

NR NS NR NS NR NS

Chlorine residual > 

1 mg/L; 30 minutes 

contact time

Monitored Reclaimed Water Quality Requirements

BOD5 

(or CBOD5) NR NR

CBOD5:

-5 mg/L (ann avg)

-6.25 mg/L (mon avg)

-7.5 mg/L (wk avg)

-10 mg/L (max)

NR 30 mg/L (30-d avg) NR -10 mg/L (mon avg)

-15 mg/L (daily max) NR NS 20 mg/L

TSS NR NR

-5 mg/L (ann avg)

-6.25 mg/L (mon avg)

-7.5 mg/L (wk avg)

-10 mg/L (max)

NR 30 mg/L (30-d avg) NR -5 mg/L (mon avg)

-10 mg/L (daily max) NR NS 20 mg/L

Bacterial indicators NR NR

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)

Total Ammonia NR NR

-2 mg/L (ann avg)

-2 mg/L (mon avg)

-3 mg/L (wk avg)

-4 mg/L (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

Nutrients NR NR

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)

NR NS NR

Phosphorus: 

1 mg/L (max)5

Nitrogen: 

4 mg/L (max)5

NR NS Phosphorus:

1 mg/L (ann avg)6
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-33

Table 4-14 Industrial reuse1

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 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. 2 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. 3 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. 4

 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. 5 For industrial uses, that do not create a mist or have potential for worker exposure, less stringent requirements may apply. 6 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.

Arizona2 California3Disinfected Tertiary Florida3 Hawaii1R-2 Water

Nevada

Category E

New Jersey

Type IV RWBR

North Carolina

Type 1

Texas1,5 

Type II

Virginia6 

Level 2

Washington5 

Class A

Treatment (System Design) 

Requirements

Unit processes

Individual Reclaimed 

Water Permit, 

case-specific2

Oxidized, coagulated, 

filtered, disinfected

Secondary treatment, 

filtration, high-level 

disinfection

Oxidized, disinfected Secondary treatment, 

disinfection Case-by-case

Filtration (or equivalent), 

unless there is no 

public access or employee 

exposure

NS Secondary treatment, 

disinfection

Oxidized, coagulated, 

filtered and disinfected

UV dose, 

if UV disinfection used NS NWRI UV Guidelines NWRI UV Guidelines 

enforced, variance allowed NS NS NS NS NS NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used 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 NS 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

Monitored Reclaimed Water Quality Requirements

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) 

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)

Without pond: 20 mg/L (or 

CBOD5 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 5 mg/L (max) 30 mg/L or 60 mg/L 

depending on design flow 30 mg/L (30-d avg) Case-by-case -5 mg/ (mon avg)

-10 mg/L (daily max) NS -30 mg/L (mon avg)

-45 mg/L (max wk) 30 mg/L

Turbidity 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 10 NTU (max) NS NS -2 NTU (avg)

-5 NTU (max)

Bacterial indicators 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)

Fecal coliform: 

-75% of samples

below detection

-25/100mL (max)

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)

NS 

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)

Fecal coliform: 

-200/100mL (mon goem),

CAT > 800/100mL

E. coli: 

126/100mL (mon geom), 

CAT > 235/100mL

Enterococci: 

-35/100mL (mon geom)

-CAT > 104/100mL

Total coliform: 

-2.2/100mL (7-d med)

-23/100mL (max)

Pathogens NS NS 

Giardia, Cryptosporidium 

sampling once each 2-yr 

period if high-level 

disinfection is required

NS TR NS NS NS NS NS 
Chapter 4 | State Regulatory Programs for Water Reuse

4-34 2012 Guidelines for Water Reuse

Table 4-15 Groundwater recharge - nonpotable reuse1

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 All state requirements are for groundwater recharge of a nonpotable aquifer. 2 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. 3 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. 4 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. 5 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). 6 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). 

Arizona2 California Florida3 Hawaii Nevada New Jersey5 North Carolina Texas Virginia6 WashingtonClass A

Treatment (System 

Design) Requirements

Unit processes Regulated by Aquifer 

Protection Permit2 Case-by-case 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

UV dose, 

if UV disinfection used NS NS NS NS ND NR NR NR NS NWRI UV Guidelines

Chlorine disinfection 

requirements, if used NS NS

TRC > 0.5 mg/L; 

15 minutes contact time 

at peak hr flow4

NS ND NR NR NR NS

Chlorine residual > 1 

mg/L 30 minutes contact 

time at peak hr flow

Monitored Reclaimed Water Quality Requirements

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)

NS ND NR NR NR NS 5 mg/L

TSS NS NS

-20 mg/L (ann avg)

-30 mg/L (mon avg)

-45 mg/L (wk avg)

-60 mg/L (max) 

NS ND NR NR NR NS 5 mg/L

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
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-35

Table 4-16 Indirect potable reuse (IPR)

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

Arizona1 California2 Florida4 Hawaii Nevada

New 

Jersey7 North Carolina Texas Virginia

Washington

Surface Percolation

Class A

Direct Groundwater Recharge8 

Class A

Streamflow Augmentation

Case-by-case

Treatment (System 

Design) Requirements

Unit processes NR

Oxidized, coagulated, 

filtered, disinfected, multiple 

barriers for pathogen and 

organics removal

Secondary treatment, filtration, 

high-level disinfection, multiple 

barriers for pathogen and 

organics removal

Case-by-case ND NR NR Case-by-case Case-by-case

Oxidized with nitrogen 

reduction, filtered, 

disinfected

Oxidized, coagulated, filtered, 

RO-treated, disinfected

Oxidized, clarified, 

disinfected

UV dose, 

if UV disinfection used NR NWRI Guidelines3 NWRI UV Guidelines enforced, 

variance allowed NS ND NR NR NS NS NWRI Guidelines NWRI Guidelines NWRI Guidelines

Chlorine disinfection 

requirements, if used 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 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

Monitored Reclaimed Water Quality Requirements

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)

NS ND NR NR 5 mg/L NS 30 mg/L 5 mg/L 30 mg/L

TSS NR NS 5 mg/L (max) NS ND NR NR NS NS 30 mg/L 5 mg/L 30 mg/L

Turbidity 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

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 coliform: 

-4/100mL (max) NS ND NR NR

Fecal coliform 

or E. coli

-20/100mL 

(30-d geom)

-75/100mL 

(max)

Enterococci

-4/100mL (30-

d geom)

-9/100mL 

(max)

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)

Total Nitrogen NR 10 mg/l (avg of 4 

consecutive samples) 10 mg/L (ann avg) NS ND NR NR NS NS NA 10 mg/L NPDES requirements to 

receiving stream 

TOC NR 0.5 mg/L

-3 mg/L (mon avg)

-5 mg/L (max); 

TOX6: 

< 0.2 (mon avg) or 0.3 mg/L 

(max); alternate limits allowed

NS ND NR NR NS NS NA 1 mg/L NS

Primary and Secondary 

Drinking Water Standards NR Compliance with most 

primary and secondary

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

Pathogens NR TR Giardia, Cryptosporidium 

sampling quarterly NS ND NR NR NS NS NS NS NS
Chapter 4 | State Regulatory Programs for Water Reuse

4-36 2012 Guidelines for Water Reuse

1 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]. 2 These requirements are DRAFT and were taken from CDPH Draft Regulations for Groundwater Replenishment with Recycled Water (CDPH, 2011). 3 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. 4 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. 5 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. 6 Total organic halides (TOX) are regulated in Florida. 7 For groundwater recharge reuse is on a case-by-case basis, State Groundwater Quality Standards must be met. 8 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. 
Chapter 4 | State Regulatory Programs for Water Reuse

2012 Guidelines for Water Reuse 4-37

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 

<http://www.cdph.ca.gov/certlic/drinkingwater/Documents/Re

charge/DraftRechargeReg-2011-11-21.pdf>.

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.

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.
Chapter 4 | State Regulatory Programs for Water Reuse

4-38 2012 Guidelines for Water Reuse

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2012 Guidelines for Water Reuse 5-1 

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.

5.1 Overview of Water Use and 

Regional Reuse Considerations 

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 

was 410,000 mgd (1.55 billion m3

/d), up from 402,000 

mgd (1.52 billion m3

/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, 

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.

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 

generates an estimated 32 bgd (121 million m3

/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 

Public

supply

11% Domestic selfsupply

1%

Irrigation

31%

Livestock

1%

Aquaculture Industrial 2%

4%

Mining

1%

Thermoelectric

49%

Figure 5-1 

Freshwater use by category in the United States

(Source: Kenny et al., 2009)
Chapter 5 | Regional Variations in Water Reuse

5-2 2012 Guidelines for 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

 Georgia Environmental Protection Division 

inventory of reuse installations

 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. 
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-3 
Chapter 5 | Regional Variations in Water Reuse

5-4 2012 Guidelines for Water Reuse

Figure 5-2 Legend

Map Code Text code Case Study Name

AZ-1 US-AZ-Gilbert Town of Gilbert Experiences Growing Pains in Expanding the 

Reclaimed Water System

AZ-2 US-AZ-Tucson Tucson Water: Developing a Reclaimed Water Site Inspection 

Program 

AZ-3 US-AZ-Sierra Vista Environmental Operations Park

AZ-4 US-AZ-Phoenix 91st Avenue Unified Wastewater Treatment Plant Targets 100

Percent Reuse

AZ-5 US-AZ-Blue Ribbon Panel Arizona Blue Ribbon Panel on Water Sustainability

AZ-6 US-AZ-Prescott Valley Effluent Auction in Prescott Valley, Arizona

AZ-7 US-AZ-Frito Lay Frito-Lay Process Water Recovery Treatment Plant, Casa Grande, 

Arizona 

CA-1 US-CA-Psychology The Psychology of Water Reclamation and Reuse: Survey Findings 

and Research Roadmap

CA-2 US-CA-San Ramon Managing a Recycled Water System through a Joint Powers 

Authority: San Ramon Valley

CA-3 US-CA-San Diego City of San Diego – Water Purification Demonstration Project

CA-4 US-CA-Orange County Groundwater Replenishment System, Orange County, California

CA-5 US-CA-North City EDR at North City Water Reclamation Plant

CA-6 US-CA-Santa Cruz Water Reuse Study at the University of California Santa Cruz 

Campus

CA-7 US-CA-Monterey Long-term Effects of the Use of Recycled Water on Soil Salinity 

Levels in Monterey County

CA-8 US-CA-Southern California MWD Metropolitan Water District of Southern California’s Local Resource 

Program 

CA-9 US-CA-Los Angeles County Montebello Forebay Groundwater Recharge Project using 

Reclaimed Water, Los Angeles County, California

CA-10 US-CA-Elsinore Valley Recycled Water Supplements Lake Elsinore

CA-11 US-CA-Temecula Replacing Potable Water with Recycled Water for Sustainable 

Agricultural Use

CA-12 US-CA-Santa Ana River Water Reuse in the Santa Ana River Watershed

CA-13 US-CA-VanderLans Leo J. Vander Lans Water Treatment Facility

CA-14 US-CA-Pasteurization Use of Pasteurization for Pathogen Inactivation for Ventura Water, 

California

CA-15 US-CA-Regulations California State Regulations

CA-16 US-CA-West Basin West Basin Municipal Water District: Five Designer Waters

CO-1 US-CO-Denver Zoo Denver Zoo

CO-2 US-CO-Denver Denver Water

CO-3 US-CO-Denver Energy Xcel Energy’s Cherokee Station

CO-4 US-CO-Denver Soil Effects of Recycled Water on Soil Chemistry

CO-5 US-CO-Sand Creek Sand Creek Reuse Facility Reuse Master Plan

CO-6 US-CO-Water Rights Water Reuse Barriers in Colorado

DC-1 US-DC-Sidwell Friends Smart Water Management at Sidwell Friends School

FL-1 US-FL-Miami So District Plant South District Water Reclamation Plant

FL-2 US-FL-Pompano Beach City of Pompano Beach OASIS

FL-3 US-FL-Orlando E. Regional Eastern Regional Reclaimed Water Distribution System 

FL-4 US-FL-Economic Feasibility Economic Feasibility of Reclaimed Water to Users

FL-5 US-FL-Reedy Creek Reuse at Reedy Creek Improvement District

FL-6 US-FL-Marco Island Marco Island, Florida, Wastewater Treatment Plant 

FL-7 US-FL-Everglade City Everglade City, Florida

FL-8 US-FL-Orlando Wetlands City of Orlando Manmade Wetlands System
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-5 

Figure 5-2 Legend

Map Code Text code Case Study Name

FL-9 US-FL-SWFWMD Partnership Regional Reclaimed Water Partnership Initiative of the Southwest 

Florida Water Management District

FL-10 US-FL-Altamonte Springs The City of Altamonte Springs: Quantifying the Benefits of Water 

Reuse

FL-11 US-FL-Clearwater Evolution of the City of Clearwater’s Integrated Water Management 

Strategy

FL-12 US-FL-Turkey Point Assessing Contaminants of Emerging Concern (CECs) in Cooling 

Tower Drift

GA-1 US-GA-Clayton County Sustainable Water Reclamation Using Constructed Wetlands: The 

Clayton County Water Authority Success Story 

GA-2 US-GA-Forsyth County On the Front Lines of a Water War, Reclaimed Water Plays a Big 

Role in Forsyth County, Georgia

GA-3 US-GA-Coca Cola Recovery and Reuse of Beverage Process Water

HI-1 US-HI-Reuse Reclaimed Water Use in Hawaii

MA-1 US-MA-Southborough Sustainability and LEED Certification as Drivers for Reuse: Toilet 

Flushing at The Fay School

MA-2 US-MA-Hopkinton Decentralized Wastewater Treatment and Reclamation for an 

Industrial Facility, EMC Corporation Inc., Hopkinton, Massachusetts

MA-3 US-MA-Gillette Stadium Sustainability and Potable Water Savings as Drivers for Reuse: 

Toilet Flushing at Gillette Stadium

ME-1 US-ME-Snow Snowmaking with Reclaimed Water

MN-1 US-MN-Mankato Reclaimed Water for Peaking Power Plant: Mankato, Minnesota

NC-1 US-NC-Cary Town of Cary, North Carolina, Reclaimed Water System

NY-1 US-NY-PepsiCo Identifying Water Streams for Reuse in Beverage Facilities: PepsiCo 

ReCon Tool

PA-1 US-PA-Kutztown The Water Purification Eco-Center

PA-2 US-PA-Mill Run Zero-Discharge, Reuse, and Irrigation at Fallingwater, Western 

Pennsylvania Conservancy

TN-1 US-TN-Franklin Franklin, Tennessee Integrated Water Resources Plan

TX-1 US-TX-San Antonio San Antonio Water System Water Recycling Program

TX-2 US-TX-Big Spring Raw Water Production Facility: Big Spring Plant

TX-3 US-TX-Landscape Study Site Suitability for Landscape Use of Reclaimed Water in the 

Southwest

TX-4 US-TX-NASA U.S. Water Recovery System on the International Space Station

TX-5 US-TX-Wetlands East Fork Raw Water Supply Project: A Natural Treatment System 

Success Story

VA-1 US-VA-Occoquan Potable Water Reuse in the Occoquan Watershed

VA-2 US-VA-Regulation Water Reuse Policy and Regulation in Virginia

WA-1 US-WA-Sequim City of Sequim’s Expanded Water Reclamation Facility and Upland 

Reuse System

WA-2 US-WA-Regulations Washington State Regulations

WA-3 US-WA-King County Demonstrating the Safety of Reclaimed Water for Garden 

Vegetables

WA-4 US-WA-Yelm City of Yelm, Washington
Chapter 5 | Regional Variations in Water Reuse

5-6 2012 Guidelines for 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 10) Oregon, 

Washington, Idaho, and Alaska. 

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)

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.
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-7 

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

and 1990-2010 (USCB, n.d.)

State or Region

% 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
Chapter 5 | Regional Variations in Water Reuse

5-8 2012 Guidelines for 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.)

State or Region

% 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
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-9 

5.2.1.1 Population and Land Use

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. 

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. 

5.2.1.3 Water Use by Sector

Figure 5-5 shows freshwater use by sector in the 

Northeast.

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 

Figure 5-5

Freshwater use by sector for the Northeast region

Public supply

16%

Domestic selfsupply

2% Irrigation

1%

Livestock

<1%

Aquaculture

2%

Industrial

6%

Mining

1%

Thermoelectric

72%

Figure 5-4

Average monthly precipitation (1971-2000) for states in 

the Northeast region

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Connecticut

Maine

Massachusetts

New Hampshire

Rhode Island

Vermont

New Jersey

New York

Figure 5-3

Percent change in population (2000-2010) and 

developed land (1997-2007) in the Northeast Region, 

compared to the United States

6.1

13.4

9.7

5.7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

Population Land Use

Percent Change

Northeast Region

US
Chapter 5 | Regional Variations in Water Reuse

5-10 2012 Guidelines for 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.

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.
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-11

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 

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 
Chapter 5 | Regional Variations in Water Reuse

5-12 2012 Guidelines for Water Reuse

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.

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 

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.

Figure 5-6

Change in population (2000-2010) and developed 

land (1997-2007) in the Mid-Atlantic region, 

compared to the United States 

7.2 

12.8

9.7

5.7

-

2.0 

4.0 

6.0 

8.0 

10.0 

12.0 

14.0 

Population Land Use

Percent Change

Mid-Atlantic Region

US
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-13

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.

5.2.2.3 Water Use by Sector

Figure 5-8 shows freshwater use by sector in the MidAtlantic Region.

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 

Figure 5-8

Freshwater use by sector for the Mid-Atlantic region

Public supply 

8%

Domestic selfsupply

1%

Irrigation

1%

Livestock

<1%

Aquaculture

2%

Industrial

7%

Mining

<1%

Thermoelectric

81%

Figure 5-7

Average monthly precipitation in the Mid-Atlantic 

region

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Delaware

Washington, DC

Maryland

Pennsylvania

Virginia

West Virginia
Chapter 5 | Regional Variations in Water Reuse

5-14 2012 Guidelines for 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 

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. 
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-15

 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, 

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 
Chapter 5 | Regional Variations in Water Reuse

5-16 2012 Guidelines for Water Reuse

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.

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 

million gallons per day (403,200 ac-ft/yr) (15.8 m3

/s)

than any other state. Part of the explanation lies in an 

initial regulatory driver to reuse instead of increasing 

deep well disposal. Figure 5-10 depicts typical 

monthly precipitation in the Southeast by state.

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. 

Figure 5-10

Average monthly precipitation in the Southeast region

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Alabama

Florida

Georgia

Kentucky

Mississippi

North Carolina

South Carolina

Tennessee

Figure 5-9

Change in population (2000-2010) and developed land 

(1997-2007) in the Southeast region, compared to the 

United States

14.7

11.2

9.7

5.7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

Population Land Use

Percent Change

Southeast Region

US
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-17

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 

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 

Figure 5-11

Freshwater use by sector for the Southeast region

Public 

supply

12%

Domestic selfsupply

1%

Irrigation

11%

Livestock

1%

Aquaculture

2%

Industrial

5%

Mining

1%

Thermoelectric

67%
Chapter 5 | Regional Variations in Water Reuse

5-18 2012 Guidelines for Water Reuse

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 

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 (7.9 m3

/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.
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-19

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 

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).
Chapter 5 | Regional Variations in Water Reuse

5-20 2012 Guidelines for 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 

434 reuse systems, where 722 mgd (31.6 m3

/ 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 

m3

/ 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.

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) 

Figure 5-12

Water reuse in Florida by type (FDEP, 2012)

Public Access 

Areas

58%

Wetlands and 

Other

5%

Groundwater 

Recharge

11%

Agriculture 

Irrigation

10%

Industrial Uses

16%
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-21

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 

(7.9 m3

/s) by 2025. These requirements are based in 

part on reducing nutrient load to the coastal waters 

(Goldenberg et al., 2009). 

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 

Figure 5-13

Map of per capita reuse flow by county in Florida 

(FDEP, 2012)

Over 50 gpd/person

Top 10 most populous counties

Below 15 gpd/person

Between 15 and 50 gpd/person

Per Capita Reuse Flow 2011

State Average = 38.19 gpd/person

Note: Calculations of reuse flow per capita includes population 

that is served by onsite sewage treatment and disposal 

systems (e.g., septic systems).
Chapter 5 | Regional Variations in Water Reuse

5-22 2012 Guidelines for Water Reuse

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 

article identified the Cary reclaimed water as 

“Purple...the new Gold” by serving as a resource 

during the drought to maintain landscape (Westmiller, 

2010).

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

(1.6 m3

/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 

Figure 5-14

Cary, N.C., bulk fill station allows approved 

contractors, landscapers, and town staff to use 

reclaimed water
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-23

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 100-

year 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. 

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.
Chapter 5 | Regional Variations in Water Reuse

5-24 2012 Guidelines for Water Reuse

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.

5.2.4.3 Water Use by Sector

Figure 5-17 shows freshwater use by sector in 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 

Figure 5-17

Freshwater use by sector for the Midwest and Great 

Lakes region

Public 

supply

10%

Domestic selfsupply

1%

Irrigation

17%

Livestock

1%

Aquaculture

1%

Industrial

5%

Mining

2%

Thermoelectric

63%

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Illinois

Illinois

Michigan

Minnesota

Ohio

Wisconsin

Iowa

Kansas

Missouri

Nebraska

Figure 5-16

Average monthly precipitation in the Midwest

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

3.9

6.9

9.7

5.7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

Population Land Use

Percent Change

Midwest and Great Lakes 

Regions

US
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-25

municipal wastewater facilities considering water reuse 

for future improvements projects.

An analysis of one state, Minnesota, is provided as a 

perspective on water use in other Midwest states.

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. 

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. 

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 

m3

/s), of which 75 mgd (3.3 m3/s) was used by 

industries in the Twin Cities area. The total WWTF

discharge for the state is 425 mgd (18.6 m3

/s), and 

255 mgd (11.2 m3

/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.

Figure 5-19

Water use in Minnesota by source*, 2007 (Source: 

MDNR 2008)

0

100

200

300

400

500

600

700

Public 

potable water 

supply

Industrial Irrigation Other

2007 Water Use, mgd

Surface

Ground

*power generation not included

Figure 5-18

Water use in Minnesota, 2007 (Source: MDNR 2008)

Public Potable 

Water Supply

16%

Other

1%

Irrigation

10%

Power Generation

61%

Industrial

12%
Chapter 5 | Regional Variations in Water Reuse

5-26 2012 Guidelines for Water Reuse

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 

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.
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-27

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. 

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 

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.

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 

Figure 5-20

The SMSC WRF and wetlands
Chapter 5 | Regional Variations in Water Reuse

5-28 2012 Guidelines for 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, 

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.

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 

Figure 5-21

Mankato Water Reclamation Facility
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-29

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. 

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.

Reclaimed water is an emerging water supply for 

Minnesota communities and industries. Economic 

development, water supply limitations, and 

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.

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.

Figure 5-22

Change in population (2000-2010) and developed 

land (1997-2007) in the South Central region, 

compared to the United States

15.5

4.3

9.7

5.7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

Population Land Use

Percent Change

South Central Region

US
Chapter 5 | Regional Variations in Water Reuse

5-30 2012 Guidelines for Water Reuse

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.

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.

Figure 5-24

Freshwater use by sector for the South Central region

Public 

supply

14%

Domestic selfsupply

1%

Irrigation

45%

Livestock

3%

Aquaculture

1%

Industrial

8%

Mining

3%

Thermoelectric

25%

Figure 5-23

Average monthly precipitation in the South Central 

region 

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Arkansas

Louisiana

New Mexico

Oklahoma

Texas
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-31

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 

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 
Chapter 5 | Regional Variations in Water Reuse

5-32 2012 Guidelines for 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 

27.5 mgd (1.2 m3

/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 

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 
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-33

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.

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. 
Chapter 5 | Regional Variations in Water Reuse

5-34 2012 Guidelines for Water Reuse

Figure 5-29

Wastewater influent strength, TSS

Figure 5-27

Wastewater influent strength, BOD5

Figure 5-28 

Wastewater influent strength, NH3-N 

Figure 5-26

Wastewater flows in El Paso, Texas

Figure 5-25

Water consumption in El Paso, Texas
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-35

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). 

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.).

5.2.6 Mountain and Plains: Colorado, 

Montana, South Dakota, North Dakota, 

Utah, and Wyoming

This section focuses on the regulatory context and 

drivers for water reuse in six states in the Mountain 

and Plains region.

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. 

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.

5.2.6.2 Precipitation

Figure 5-31 depicts average monthly precipitation in 

the Mountain and Plains region by state.

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.

Figure 5-31

Average monthly precipitation in the Mountain and 

Plains region

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Colorado

Montana

North Dakota

South Dakota

Utah

Wyoming

16.1

1.7

9.7

5.7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

Population Land Use

Percent Change

Mountain and Plains 

Region

US

Figure 5-30

Change in population (2000-2010) and developed land 

(1997-2007) in the Mountain and Plains region, 

compared to the United States
Chapter 5 | Regional Variations in Water Reuse

5-36 2012 Guidelines for Water Reuse

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.

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 R317-3-

11 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. 

Figure 5-32

Freshwater use by sector for the Mountain and Plains 

region

Public supply

8% Domestic selfsupply

<1%

Irrigation

70%

Livestock

2%

Aquaculture

2%

Industrial

1%

Mining

2%

Thermoelectric

15%
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-37

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 

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.
Chapter 5 | Regional Variations in Water Reuse

5-38 2012 Guidelines for Water Reuse

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 

6,463 mi2 comprise an island chain stretching 

northwest to southeast over a zone 430 mi long.

5.2.7.2 Precipitation and Climate

Figure 5-34 depicts average monthly precipitation in 

the states of the Pacific Southwest—Arizona, 

California, Hawaii, and Nevada.

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 

Figure 5-34

Average monthly precipitation in the Pacific Southwest 

region

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Arizona

California

Hawaii

Nevada

Figure 5-33

Change in population (2000-2010) and developed land 

(1997-2007) in the Pacific Southwest region, compared 

to the United States

13.0

3.6

9.7

5.7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Population Land Use

Percent Change

Pacific Southwest Region

US
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-39

events are combined with below freezing 

temperatures.

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. 

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 

industry with over 80 mgd (3.5 m3

/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 

Public supply

19%

Domestic selfsupply

1%

Irrigation

49%

Livestock

<1%

Aquaculture

1%

Industrial

1%

Mining

2%

Thermoelectric

27%

Figure 5-35

Freshwater use by sector for the Pacific Southwest 

region
Chapter 5 | Regional Variations in Water Reuse

5-40 2012 Guidelines for Water Reuse

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.

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).
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-41

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 

(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 
Chapter 5 | Regional Variations in Water Reuse

5-42 2012 Guidelines for Water Reuse

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].

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.

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.

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, 

Figure 5-37

Uses of recycled water in Calif. (SWRCB 2011)

Agricultural Irrigation 

244,500

37%

Geothermal Energy 

Production 14,900

2%

Golf Course Irrigation 

43,600

7%

Landscape 

Irrigation 112,600

17% Industrial 47,100

7%

Commercial 6,400

1%

Seawater Intrusion 

Barrier 47,100

7%

Recreational 

Impoundment 25,800

4%

Natural System 

Restoration, Wetlands, 

Wildlife Habitat 29,600

4%

Other 15,800

2%

Groundwater Recharge 

79,700

12% 2009

669,000 acre-feet

Figure 5-36

2010 Reclaimed water use in Tucson, Ariz.

52 Schools

8%

Other

6%

18 Golf Courses

56%

Other Providers

13%

39 Parks

17%

CY 2010 deliveries – 16,125 ac-ft
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-43

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.

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 
Chapter 5 | Regional Variations in Water Reuse

5-44 2012 Guidelines for Water Reuse

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.

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 

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.
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-45

5.2.8.1 Population and Land Use

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.

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. 

Eastern Washington has roughly twice the land area 

and one-third the population of western Washington. 

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 

Figure 5-39

Average monthly precipitation in the Pacific Northwest 

region

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sept

Oct

NovDec

Average Rainfall (inches)

Month

Alaska

Idaho

Oregon

Washington

Figure 5-38

Change in population (2000-2010) and developed land 

(1997-2007) in the Pacific Northwest region, compared 

to the United States

14.2

3.0

9.7

5.7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

Population Land Use

Percent Change

Pacific Northwest Region

US
Chapter 5 | Regional Variations in Water Reuse

5-46 2012 Guidelines for 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.

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 

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 

Public 

supply

10%

Domestic selfsupply

1%

Irrigation

38%

Livestock

<1%

Aquaculture

15%

Industrial

3%

Mining

3%

Thermoelectric

30%

Figure 5-40

Freshwater use by sector for the Pacific Northwest 

region
Chapter 5 | Regional Variations in Water Reuse

2012 Guidelines for Water Reuse 5-47

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.

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 
Chapter 5 | Regional Variations in Water Reuse

5-48 2012 Guidelines for 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 [USWA-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

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CH2MHill. 2011. Talking Water Gardens Natural Water 

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Elfland, C. 2010. “UNC Chapel Hill’s Sustainable Water 

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2012 Guidelines for Water Reuse 5-49

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Reuse Inventory. Florida Department of Environmental 

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Florida Department of Environmental Protection (FDEP). 

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_reuse-report.pdf>. 

Florida Department of Environmental Protection. 2012b. 

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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

<http://pubs.usgs.gov/circ/1344/pdf/c1344.pdf>. 

Metropolitan Area Planning Council (MAPC). 2005. “Once is 

Not Enough: A Guide to Water Reuse in Massachusetts.” 

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<http://www.495partnership.org/assets/Water/3-

1%20Once%20is%20Not%20Enough%20-

%20Guide%20to%20Water%20Reuse%2010-05.pdf>. 

Metropolitan Council Environmental Services (MCES). 2007. 

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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 

<http://www.metrocouncil.org/planning/environment/RTMWI

WU/RecyclingWastewater.htm>.

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

<http://www.dnr.state.mn.us/waters/watermgmt_section/appr

opriations/wateruse.html>. 

Minnesota Pollution Control Agency (MPCA). 2011. “Salty 

Discharge” Monitoring at NPDES/SDS Permitted Facilities.

Retrieved on August 23, 2012 from 

<http://www.pca.state.mn.us/index.php/viewdocument.html?gid=16079>. 

Minnesota Pollution Control Agency (MPCA). 2010a. 

Biofuels: Reusing Municipal Wastewater. Retrieved on 

August 23, 2012 from 

<http://www.pca.state.mn.us/index.php/viewdocument.html?gid=13494>. 

Minnesota Pollution Control Agency (MPCA). 2010b. 

Municipal Wastewater Reuse. Retrieved on August 23, 2012 

from <http://www.pca.state.mn.us/index.php/viewdocument.html?gid=13496>. 

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.
Chapter 5 | Regional Variations in Water Reuse

5-50 2012 Guidelines for Water Reuse

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.

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Center. El Paso, TX.

National Oceanic and Atmospheric Administration (NOAA). 

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precipitation data. Retrieved on August 23, 2012 from

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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

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%2002%20-

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Galveston, TX.

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nts_loans/water_recycling/munirec.shtml>. 

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For New Mexico. New Mexico Water Resources Institute, 

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2012 Guidelines for Water Reuse 5-51

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Water Quality Standards for the State of Florida. Retrieved 

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ReuseAA.pdf>. 

Vandertulip, D. and L. Pype. 2009. “Water Reuse Practices – 

Current Uses and Future Trends.” Pennsylvania Water 

Environment Association PENNTEC 2009, June 9, 2009.

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Whole New World of Reuse Opportunities.” Montana Section 

AWWA/WEA Annual Conference, May 15, 2008. Great Falls, 

MT. 

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“Texas 2003 Reuse Rule Revisions.” AWWA/WEF Water 

Sources Conference, January 2004.

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Westmiller, R. 2010. “Purple, the New Gold.” Irrigation and 

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Whitcomb, J. B. 2005. Florida Water Rates Evaluation of 

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Management District, St. Johns River Water Management 

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e_report.pdf>. 

WRA News. 2011. Bureau of Reclamation Awards $1.2 

Million for Water Reuse Studies in Three States. Retrieved 

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Wu, M., M. Mintz, M. Wang, and S. Arora. 2009. 

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Petroleum Gasoline. Center for Transportation Research, 

Energy Systems Division, Argonne National Laboratory. 
Chapter 5 | Regional Variations in Water Reuse

5-52 2012 Guidelines for Water Reuse

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2012 Guidelines for Water Reuse 6-1 

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). 

WWTP DAF Media

Filtration Ozone BAC/GAC UF BufferBlend WTP

WWTP MF RO IX UV-A Buffer

Blend WTP

WWTP MF RO UV-A Buffer WTP

WWTP MF GAC Ozone Buffer

Blend WTP

California Model IPR

Surface Water (nutrients)

RO UV-A Buffer MBR Blend WTP

Namibia Model (No RO)

Gwinnett County IPR

Cloudcraft Model (MBR)

Figure 6-1 

Potable reuse treatment scenarios (Chalmers et al., 2011)
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-2 2012 Guidelines for Water Reuse

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

Treatment 

Level 

Increasing Levels of Treatment

Primary Secondary Filtration and 

Disinfection Advanced

Processes Sedimentation Biological oxidation and 

disinfection

Chemical coagulation, 

biological or chemical 

nutrient removal, filtration, 

and disinfection

Activated carbon, reverse 

osmosis, advanced 

oxidation processes, soil 

aquifer treatment, etc. 

End Use No Uses 

Recommended

Surface irrigation of 

orchards and vineyards

Landscape and golf 

course irrigation

Indirect potable reuse 

including groundwater 

recharge of potable aquifer 

and surface water reservoir 

augmentation and potable 

reuse 

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
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-3 

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). 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-4 2012 Guidelines for Water Reuse

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 

scale (e.g., 1 million = 106 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 

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. 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-5 

Table 6-2 Infectious agents potentially present in untreated (raw) wastewater

Pathogen Disease

Numbers in Raw 

Wastewater (per liter)

Bacteria

Shigella Shigellosis (bacillary dysentery) Up to 104

Salmonella Salmonellosis, gastroenteritis (diarrhea, 

vomiting, fever), reactive arthritis, typhoid fever Up to 105

Vibro cholera Cholera Up to 105

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 Up to 104

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

Protozoa

Entamoeba Amebiasis (amebic dysentery) Up to 102

Giardia Giardiasis (gastroenteritis) Up to 105

Cryptosporidium Cryptosporidiosis, diarrhea, fever Up to 104

Microsporidia Diarrhea

Cyclospora Cyclosporiasis (diarrhea, bloating, fever, 

stomach cramps, and muscle aches)

Toxoplasma Toxoplasmosis

Helminths

Ascaris Ascariasis (roundworm infection) Up to 103

Ancylostoma Ancylostomiasis (hookworm infection) Up to 103

Necator Necatoriasis (roundworm infection)

Ancylostoma Cutaneous larva migrams (hookworm infection)

Strongyloides Strongyloidiasis (threadworm infection)

Trichuris Trichuriasis (whipworm infection) Up to 102

Taenia Taeniasis (tapeworm infection), 

neurocysticercosis

Enterobius Enterobiasis (pinwork infection)

Echinococcus Hydatidosis (tapeworm infection)

Viruses

Enteroviruses (polio, echo, coxsackie, new 

enteroviruses, serotype 68 to 71)

Gastroenteritis, heart anomalies, meningitis, 

respiratory illness, nervous disorders, others Up to 106

Hepatitis A and E virus Infectious hepatitis

Adenovirus Respiratory disease, eye infections, 

gastroenteritis (serotype 40 and 41) Up to 106

Rotavirus Gastroenteritis Up to 105

Parvovirus Gastroenteritis
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-6 2012 Guidelines for Water Reuse

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 Up to 109

Coronavirus Gastroenteritis

(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 

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. 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-7 

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 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-8 2012 Guidelines for Water Reuse

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 

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. 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-9 

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): 

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 

Table 6-3 Indicative log removals of indicator microorganisms and enteric pathogens during various stages of 

wastewater treatment 

Type of Microorganism

Indicator microorganisms Pathogenic microorganisms Escherichia coli (indicator bacteria) Clostridium perfringens Phage (indicator virus) Enteric bacteria (e.g., Campylobacter) Enteric viruses Giardia lamblia Cryptosporidium parvum

Helminths

Bacteria X X X 

Protozoa and helminths X X X 

Viruses X X 

Indicative Log Reductions in Various Stages of Wastewater Treatment1

Secondary treatment 1 - 3 0.5 - 1 0.5 - 2.5 1 - 3 0.5 - 2 0.5 - 1.5 0.5 - 1 0 - 2 

Dual media filtration2 0 - 1 0 - 1 1 - 4 0 - 1 0.5 - 3 1 - 3 1.5 - 2.5 2 - 3 

Membrane filtration (UF, 

NF, and RO)3 4 - >6 >6 2 - >6 >6 2 - >6 >6 4 - >6 >6

Reservoir storage 1 - 5 N/A 1 - 4 1 - 5 1 - 4 3 - 4 1 - 3.5 1.5 - >3

Ozonation 2 - 6 0 - 0.5 2 - 6 2 - 6 3 - 6 2 - 4 1 - 2 N/A

UV disinfection 2 - >6 N/A 3 - >6 2 - >6 1 ->6 3 - >6 3 - >6 N/A

Advanced oxidation >6 N/A >6 >6 >6 >6 >6 N/A

Chlorination 2 - >6 1 - 2 0 - 2.5 2 - >6 1 - 3 0.5 - 1.5 0 - 0.5 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
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-10 2012 Guidelines for Water Reuse

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 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-11

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 

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 be 

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.
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-12 2012 Guidelines for Water Reuse

 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., 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-13

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 Examples

Industrial chemicals 1,4-Dioxane, perflurooctanoic acid, methyl tertiary butyl ether, tetrachloroethane

Pesticides, biocides, and herbicides Atrazine, lindane, diuron, fipronil

Natural chemicals Hormones (17β-estradiol), phytoestrogens, geosmin, 2-methylisoborneol

Pharmaceuticals and metabolites

Antibacterials (sulfamethoxazole), analgesics (acetominophen, ibuprofen), betablockers (atenolol), antiepileptics (phenytoin, carbamazepine), veterinary and 

human antibiotics (azithromycin), oral contraceptives (ethinyl estradiol)

Personal care products Triclosan, sunscreen ingredients, fragrances, pigments

Household chemicals and food 

additives

Sucralose, bisphenol A (BPA), dibutyl phthalate, alkylphenol polyethoxylates, flame 

retardants (perfluorooctanoic acid, perfluorooctane sulfonate)

Transformation products NDMA, HAAs, and THMs
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-14 2012 Guidelines for Water Reuse

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 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-15

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. 

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]. 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-16 2012 Guidelines for Water Reuse

Table 6-5 Indicative percent removals of organic chemicals during various stages of wastewater treatment

Treatment

Percent Removal

B(a)p Antibiotics1

Pharmaceuticals Hormones

DZP CBZ DCF IBP PCT Steroid Fragrance NDMA 2 Anabolic3

Secondary

(activated sludge) nd 10–50 nd – 10–50 >90 nd >90 nd 50–90 – 

Soil aquifer 

treatment nd nd nd 25–50 >90 >90 >90 >90 nd >90 >90

Aquifer storage nd 50–90 10–50 – 50–90 50–90 Nd >90 nd – – 

Microfiltration nd <20 <20 <20 <20 <20 <20 <20 nd <20

Ultrafiltration/ 

powdered activated 

carbon (PAC)

nd >90 >90 >90 >90 >90 nd >90 nd >90 >90

Nanofiltration >80 50–80 50–80 50–80 50–80 50–80 50–80 50–80 50–80 50–80

Reverse osmosis >80 >95 >95 >95 >95 >95 >95 >95 >95 >95 25–50

PAC >80 20–>80 50–80 50–80 20–50 <20 50–80 50–80 50–80 50–80

Granular activated 

carbon >90 >90 >90 >90 >90 >90 >90 >90

Ozonation >80 >95 50–80 50–80 >95 50–80 >95 >95 >80 50–90 50–90

Advanced oxidation 50–80 50–80 >80 >80 >80 >80 >80 >80 50–80 >90

High-level ultraviolet 20–>80 <20 20–50 >80 20–50 >80 >80 20–50 nd >90

Chlorination >80 >80 20–50 –<20 >80 <20 >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
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-17

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 

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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6-18 2012 Guidelines for Water Reuse

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. 

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. 

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 

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.

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. 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-19

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. 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-20 2012 Guidelines for Water Reuse

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 

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). 
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2012 Guidelines for Water Reuse 6-21

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. 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-22 2012 Guidelines for Water Reuse

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 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-23

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 

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 

technologies are approved for operation at 2 gpm/ft2

(traveling bridge filters) and 5 gpm/ft2 (mono-, dual-, or 

mixed-media filters), and disinfection with chlorine gas 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-24 2012 Guidelines for Water Reuse

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 

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 

gpm/ft2

 (1200 L/min/m2), 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 

hydraulic loading rates up to 6 gpm/ft2 (230 L/min/m2

), 

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 

gpm/ft2 (620 L/min/m2

), 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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-25

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.

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 

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. 

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 

Table 6-6 Summary of filter type characteristics1

Filter Type Filtration Driving Force Nominal Pore Size, um Contaminants targeted

for removal

Depth

Non-Compressible Media Gravity or pressure differential 60-300 TSS, turbidity, some protozoan 

oocysts and cysts

Compressible Media

Surface Filtration

Surface Filtration Gravity 5-20 TSS, turbidity, some protozoan 

oocysts and cysts

Membrane2

Microfiltration Pressure differential 0.05

TSS, turbidity, some protozoan 

oocysts and cysts, some bacteria 

and viruses

Ultrafiltration Pressure differential 0.002-0.050 Macromolecules, colloids, most 

bacteria, some viruses, proteins

Nanofiltration Pressure differential <0.002 Small molecules, some 

hardness, viruses

Reverse Osmosis Pressure differential <0.002

Very small molecules, color, 

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)
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-26 2012 Guidelines for Water Reuse

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 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-27

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 Florida2

Chlorination 450 mg-min/L CrT1

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

UV

100 mJ/cm2 following sand or cloth 

filtration; 80 mJ/cm2 following MF or 

UF; 50 mJ/cm2 following RO

No uniform standard

Ozone 1 mg-min/L CT1 No standard

Pasteurization 10 second contact time at 179 degrees 

F No 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.
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-28 2012 Guidelines for Water Reuse

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). 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-29

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 

mJ/cm2

), but higher doses are required to meet the 5-

log virus requirement (100 mJ/cm2

) (NWRI, 2003). UV 

dose is measured in millijoules seconds per cm2

(mJ/cm2

) and is calculated by multiplying the UV 

intensity measured in mW/cm2 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 

for “tertiary recycled water” (100, 80 or 50 mJ/cm2

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. 

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):
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-30 2012 Guidelines for Water Reuse

 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 75-

percent 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 

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). 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-31

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).

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 

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).

Figure 6-2

Pasteurization demonstration system in Ventura, Calif. 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-32 2012 Guidelines for Water Reuse

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 

state, or Fe+6, 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 

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 

Figure 6-3

Example WRF treatment train that includes UV/H2O2 AOP
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-33

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)

Oxidizing Agent EOP [V]

EOP Relative 

to Chlorine

Hydroxyl Radical 2.80 2.05

Ozone 2.08 1.52

Peracetic Acid1 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

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 

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. 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-34 2012 Guidelines for Water Reuse

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 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-35

(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 

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, 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-36 2012 Guidelines for Water Reuse

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. 

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 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-37

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].

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. 

6.4.5.3 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 

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. 

6.4.6 Monitoring for Treatment 

Performance 

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 concentrations and diversion 

alternatives; 

2. Individual evaluation of multiple barriers that 

mitigate pathogenic contaminants; 

3. Robust study designs to determine contaminant 

fate e.g. biodegradation, sorption, photolysis, or 

health effects like gastrointestinal illness; 

4. Documented travel time without short circuits; 

5. Certified operators; and 

6. Communication protocols for corrective actions.

While the appropriate monitoring parameters represent 

an ongoing subject of research, particularly for potable 

reuse applications, the selection of which biological 

and chemical constituents to monitor must be carried 

out as part of a larger QA/QC program, as described in 

Chapter 4. But, it is useful to highlight some case 

study examples of performance assessment and 

monitoring to demonstrate that the treatment practices 

described in this chapter have been shown to be 

effective for meeting the objectives for the specified 

end uses of the treated reclaimed water. 

As part of the Montebello Forebay Groundwater 

Recharge Project, five studies were conducted 

following initial replenishment efforts in 1962: Pomona 

Virus Study, 1977; Health Effects Study, 1984; An

Investigation of Soil Aquifer Treatment for Sustainable 

Water Reuse, 2006; Rand Study, 1996; and Rand 

Study, 1999 [US-CA-Los Angeles County]. These 

studies included flow modeling, virus monitoring, 

toxicology, and limited epidemiological studies and 

showed that the majority of CECs are effectively 

removed through SAT. 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

6-38 2012 Guidelines for Water Reuse

In King County, Wash. [US-WA-King County], all 

reclaimed water meets “Class A” standards and is safe 

to use for irrigating food crops. However, to both gain 

customer confidence and illustrate that local soil and 

reclaimed water characteristics are suitable for a range 

of crops, King County partnered with the University of 

Washington to conduct a greenhouse study and a field 

trial to test for the potential for pathogen transfer and 

metal uptake from reclaimed water to garden 

vegetables. Soils, water samples, and washed and 

unwashed edible portion of plant tissue were analyzed 

for bacterial indicators (total coliforms, fecal coliforms, 

and E. coli) and heavy metals. Metal concentrations in 

the reclaimed water were at least two orders of 

magnitude below EPA regulations for drinking water, 

and the bacteria tests were either negative or below 

the state regulatory limit of 2 cfu per 100 mL. 

In Tossa de Mar, Costa Brava, Spain, the 

implementation of a reuse system that distributes 

reclaimed water for landscape irrigation in public 

spaces, fire hydrants, and wash-down water at a dog 

shelter included an extensive assessment of the 

overall human health infection risk and an ongoing 

monitoring program. The high quality of reclaimed 

water, the systematic follow-up studies, and the 

educational programs implemented have all 

contributed to assure a very positive public perception 

[Spain-Costa Brava]. 

6.4.7 Energy Considerations in Reclaimed 

Water Treatment

Conventional wastewater treatment is an energyintensive process, and adding filtration and disinfection 

systems, which is a typical practice to upgrade 

WWTPs for water reclamation for nonpotable reuse, 

only adds to energy consumption. Overall, the energy 

use in this scenario is dominated by pumping, 

aeration, and disinfection. It is critical to note that the 

quality of the water being disinfected will dictate the 

energy requirements for this process. For instance, for 

UV disinfection, a nitrified filtered secondary effluent 

with a UVT of 70 percent will require about half as 

much energy to disinfect as a non-nitrified filtered 

secondary effluent with a UVT of 55 percent (WRRF, 

2012h). 

Treatment alternatives that lower energy requirements 

represent the future of reclaimed water treatment. A 

recent study by the WRRF examined processes that 

could provide dramatic energy savings. In general, 

new approaches are moving treatment process toward 

higher mechanical efficiency, decreased oxygen use, 

and more effective biochemistry. The tradeoff to these 

gains may be increased complexity and reliance on 

technology. The full evaluation of the costs and 

benefits of these technologies must be conducted for a 

specific site based on local power rates, but general 

trends in energy savings are presented in Challenge 

Projects on Low Energy Treatment Schemes for Water 

Reuse (WRRF, 2012h). 

Disinfection processes can make up about a third of 

the total energy used at a WWTP, excluding pumping 

energy (WEF, 2009; EPRI, 2002). Novel approaches 

including pasteurization, UV disinfection using light 

emitting diodes (LEDs), and electrochemical reactors 

for combined coagulation/filtration/disinfection have 

potential to reduce this power demand. As discussed 

in Section 6.4.3.4, pasteurization has undergone 

rigorous testing, demonstrating near-zero energy input 

by capturing waste heat, and is now undergoing largescale piloting. UV LEDs save energy through the use 

of a better UV dose distribution, but this technology is 

at the very early stages of development for wastewater 

disinfection.

As aeration is a key consumer of energy at WWTPs, 

significant research has gone into optimizing 

processes to minimize this requirement. A range of 

energy-saving technologies at different levels of 

development offer up to 50 percent energy savings 

through improvements in aeration or reduced aeration 

requirements, optimized microorganisms for nutrient 

removal processes, and novel anaerobic processes 

(WRRF, 2012h).

In typical nonpotable reuse applications, filtration 

makes up about 3 percent of the total energy use of a 

WWTP (WEF, 2009; EPRI, 2002). While representing 

a small percentage of the overall energy budget, 

improved filtration technologies that optimize filtration 

backwash modes or the type of filter media have 

demonstrated reduced energy use compared to 

conventional sand filtration (Parkson, 2011). 

Natural treatment of reclaimed water in wetlands or 

through managed aquifer recharge systems are key 

treatment options for water reuse. These systems, in 

addition to potentially providing secondary 

environmental benefits such as enhanced stream 

flows, wildlife habitat, or a barrier from saltwater 

intrusion into groundwater, can also reduce the energy 
Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health

2012 Guidelines for Water Reuse 6-39

footprint of the overall treatment system, depending on 

the treatment application. Additional discussion of 

managed aquifer recharge is provided in Section 2.3.3; 

and a description of the treatment mechanisms 

through wetlands and SAT systems are provided in 

Section 6.4.5. 

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2012 Guidelines for Water Reuse 7-1 

CHAPTER 7 

Funding Water Reuse Systems

This chapter provides an overview of the financial 

viability of reclaimed water and also includes 

resources for how to properly fund reclaimed water 

systems.

7.1 Integrating Reclaimed Water into a 

Water Resource Portfolio 

Historically, wastewater utility systems have entered 

into long-term agreements with agricultural and golf 

course customers to deliver reclaimed water at little or 

no cost. Giving treated effluent away was viewed as 

mutually beneficial. Many of those original agreements 

for low cost reclaimed water have recently expired—or 

will soon expire—creating an opportunity to develop 

reasonable rates and charges for the value provided. 

Reclaimed water is now widely recognized as a fullfledged component of integrated water resources 

planning. As a result, ensuring adequate funding for 

reclaimed water systems is not dissimilar from funding 

other water services. Developing and operating a 

sustainable water system requires the use of sound 

business decision-making processes that are closely 

tied to the system’s strategic planning process. The 

underlying principles for a reclaimed water system’s 

funding strategy should reflect the following:

1. Revenues from rates and charges should be 

sufficient to provide annual operating 

maintenance and repair expenses, capital 

improvements costs, adequate working capital, 

and required reserves.

2. Accounting practices should separate reclaimed

water accounts from other governmental or 

entity operations for transparency and to 

prevent diversion of funds to uses unrelated to 

water services; this concept is typically reflected 

by use of an enterprise fund, which may be 

stand alone for the reclaimed water system, or 

combined with the utility’s potable water and 

wastewater systems.

3. Accounting practices should adhere to generally

accepted accounting principles and comply with 

applicable regulatory requirements.

4. Rates and fees should equitably distribute the 

cost of water service based on cost-of-service 

principles, compliance with legal requirements, 

and transparency of communication regarding 

non-quantifiable benefits to rate payers.

5. Budgeting should be adequate to support asset 

management, including planned and preventive 

maintenance, as well as infrastructure reinvestment.

There are a number of existing resources to assist 

utilities in understanding and implementing these 

principles, including:

 Principles of Water Rates, Fees, and Charges, 

5th Edition (AWWA, 2000) 

 Water Rates, Fees, and the Legal Environment, 

2nd Edition (AWWA, 2010)

 Financing and Charges for Wastewater 

Systems, (MOP 27) (WEF, 2004)

 Governmental Accounting, Auditing, and 

Financial Reporting: Using the GASB 34 Model

(GFOA, 2005)

 Water Reuse Rates and Charges, Survey 

Results, (AWWA, 2008)

Nonetheless, utilities often set reclaimed water rates 

lower than potable water rates to promote customer

conversion to reclaimed water use. In general, 

reclaimed water is priced from 50 percent to 100 

percent of potable water with the median rate 80 

percent of potable water rates (AWWA, 2008). This 

discount enables users to pay for retrofit costs, plus it 

serves as an incentive to use reclaimed water. There 

are some jurisdictions where reclaimed water is priced 

at full parity with potable water, especially where 

reclaimed water is not subject to the potable water use 

restrictions during droughts. 

The initiation and maintenance of a sound funding 

strategy for reuse programs requires prudent financial 

decisions and accounting controls, as well as a 
Chapter 7 | Funding Water Reuse Systems

7-2 2012 Guidelines for Water Reuse

comprehensive understanding of the technical, 

economic, and social factors that ultimately determine 

the sustainability of a system’s water resource 

portfolio. A planning process referred to as “Integrated 

Resource Planning” is often used as a means of 

accruing information that is critical to a fiscally and 

socially sustainable water system. 

A holistic planning process such as IRP sets the stage 

for clearly communicating an integrated funding 

strategy while characterizing and communicating both 

the costs and benefits of particular elements of the 

water resources management program. This 

comprehensive and transparent decision-making 

framework is critical to sustainable funding to ensure 

that water management meets a community’s needs. 

In an uncertain business environment (e.g., economic 

volatility, climate change), sustainable water utility 

funding strategies are based on a combination of 

capital, operations and maintenance considerations, 

and revenue tools that provide the greatest value for 

the system and its customers, while minimizing the 

potential “regret” of making a poor investment. 

A number of useful integrated planning resources have 

been published in recent years. The Water Resources 

Planning, Manual of Water Supply Practices (M50) 

(AWWA, 2007), Evaluating Pricing Levels and 

Structures to Support Reclaimed Water Systems 

(WRRF, 2009), Water Reuse Economic Framework 

Workshop Report (WRRF, 2004), An Economic 

Framework for Evaluating Benefits and Costs of Water 

Reuse (WRRF, 2006), and EPA’s draft Total Water 

Management document (Rodrigo et al., 2012) provide 

specific guidance on incorporating reuse into water 

resources plans.

7.2 Internal and Debt Funding 

Alternatives

While there are several mechanisms for funding 

reclaimed water systems, utilities typically use internal 

funding and debt funding. 

Internal funding is based on revenue generated from 

customers. The customers can be individual largevolume users or a wide network of users within the 

water reuse district or a region that has an agreement 

with the utility for taking and paying for the product. 

Large-volume customers, if available, can finance a 

significant portion of a project and may have welldefined water quality objectives that would impact the 

nature and character of the treatment and distribution 

system. They may, in fact, dictate these requirements 

to the utility and be willing to reserve reclaimed water 

for their operations. Typically these customers are 

industrial users, large-scale agricultural operations, or 

golf courses. The concern for the utility is the risk of 

losing the large-volume customer or the revenue from 

the service agreement. Protection for both parties 

should be incorporated into any service agreements 

that are based on revenue being generated from a 

small number of large customers. The utility will need 

to determine and weigh the risk of losing funding from 

this type of arrangement. 

There are several forms of debt funding, including 

revenue bonds and low interest loans. The benefits of 

these funding instruments are that they are typically 

long-term with the funding received up-front from 

bondholders, in contrast to the project being funded 

internally through an agreement with a large customer 

where funding is obtained from rates over the life of 

the project. 

Revenue bonds are supported by net operating 

income from recurring utility charges. These 

instruments are issued based on internal policy and 

financial standing through a bond counsel. The 

requirements include the assurance that the capital 

and operations and replacement costs are covered by 

the rates being charged with typically a 10 percent to 

25 percent debt service coverage generation, 

depending on the bonding authority or other 

requirements.

7.2.1 State and Federal Financial 

Assistance

Where available, grant programs are an attractive 

funding source, but they require that the proposed 

system meets grant eligibility requirements. These 

programs reduce the total capital cost borne by system 

beneficiaries, thus improving the affordability and 

viability of the project. Some funding agencies have an 

increasingly active role in facilitating water reuse 

projects. In addition, many funding agencies are 

receiving a clear legislative and executive mandate to 

encourage water reuse in support of water 

conservation.

To be financially successful over time, a reuse 

program, however, must be able to “pay for itself.” 

While grant funds may underwrite portions of the 
Chapter 7 | Funding Water Reuse Systems

2012 Guidelines for Water Reuse 7-3 

capital improvements necessary in a reuse project—

and in a few states, state-supported subsidies can also 

help a program to establish itself in early years of 

operation—grant funds should not be used for funding 

needs associated with annual operating costs. In fact, 

most federally-funded grant and loan programs 

explicitly prohibit the funding of operation, 

maintenance, and replacement (OM&R) costs. Once 

the project is underway, the program should strive to 

achieve self-sufficiency as quickly as possible, 

meeting OM&R costs and debt service requirements of 

the local share of capital costs by generating an 

adequate stream of revenues through local sources.

7.2.1.1 Federal Funding Sources

The CWA of 1977, as amended, has supported water 

reuse projects through the following provisions:

 Section 201 of PL 92-500 was amended to 

ensure that municipalities are eligible for “201” 

funding only if they have “fully studied and 

evaluated” techniques for “reclaiming and reuse 

of water”. A 201 facility plan study must be 

completed to qualify for state revolving loan 

funds.

 Section 214 stipulates that the EPA 

administrator “shall develop and operate a 

continuing program of public information and 

education on water reclamation and reuse of 

wastewater...”

 Section 313, which describes pollution control 

activities at federal facilities, was amended to 

ensure that WWTFs will utilize “recycle and 

reuse techniques: if estimated life-cycle costs 

for such techniques are within 15 percent of the 

most cost-effective alternative.”

There are a number of federal sources that might be 

used to generate funds for a water reuse project. 

While there are many funding sources, only certain 

types of applicants or projects are eligible for 

assistance under each program, with annual funding 

dependent on congressional authorizations. 

The USDA has several programs that may provide 

financial assistance for water reuse projects in rural 

areas, but the definition of a rural area varies 

depending upon the statutory language authorizing the 

program. Most of these programs are administered 

through the USDA Rural Development Office in each 

state.

Rural Utilities Service (RUS) offers funds through the 

Water and Waste Program, in the form of loans, 

grants, and loan guarantees. The largest is the Water 

and Waste Loan and Grant Program, with 

approximately $1.5 billion available nationwide per 

year. This program offers financial assistance to public 

bodies, eligible not-for-profits, and recognized tribal 

entities for development (including construction and 

non-construction costs) of water and wastewater 

infrastructure. Unincorporated areas are typically 

eligible, as are communities with less than 10,000 

people. Grants may be available to communities 

meeting income limits to bring user rates down to a 

level that is reasonable for the serviced population. 

Interest rates for loan assistance depend on income 

levels in the served areas as well. The Rural 

Development offices act to oversee the RUS-funded 

projects from initial application until the operational 

stage.

The Rural Housing Service (RHS) also known as Rural 

Development Housing and Community Facilities 

Programs (HCFP) is a division within the USDA’s 

Rural Development agency that administers aid to 

rural communities. The HCFP may fund a variety of 

projects for public bodies, eligible not-for-profits, and 

recognized tribal entities where the project serves the 

community. The HCFP provides grants to assist in the 

development of essential community facilities in rural 

areas and towns of up to 20,000 in population. 

The Rural Business-Cooperative Service offers the 

Rural Business Enterprise Grant (RBEG) program. 

The RBEG program is a broad-based program that 

reaches to the core of rural development in a number 

of ways. Examples of eligible fund use include: 

acquisition or development of land, easements, or

rights of way; construction activities, pollution control; 

and abatement and project planning. Any project 

funded under the RBEG program should benefit small 

and emerging private businesses in rural areas. A 

water reuse system serving a business or industrial 

park could potentially receive grant assistance through 

this program. An individual eligible business could 

apply for loan guarantees through the Rural BusinessCooperative Service to help finance a water reuse 

system that would support the creation of jobs in a 

rural area.
Chapter 7 | Funding Water Reuse Systems

7-4 2012 Guidelines for Water Reuse

Other agencies that have funded projects in 

cooperation with USDA may provide assistance for 

water reuse projects if eligibility requirements are met, 

include the Economic Development Administration, 

Housing and Urban Development (Community 

Development Block Grant), Appalachian Regional 

Commission, and the Delta Regional Commission. 

Finally, USBR, authorized under Title XVI, the 

Reclamation Wastewater and Groundwater Study and 

Facilities Act; PL 102-575, as amended, Reclamation 

Recycling and Water Conservation Act of 1996; PL 

104-266, Oregon Public Lands Transfer and Protection 

Act of 1998; PL 105-321, and the Hawaii Water 

Resources Act of 2000; PL 106-566, provides for 

USBR to conduct appraisal and feasibility studies on 

water reclamation and reuse projects. USBR can then 

fund construction of reuse projects after Congressional 

approval of the appropriation. This funding source is 

restricted to activities in the 17 western states unless 

otherwise authorized by Congress. Federal 

participation is generally up to 25 percent of the capital 

cost.

Information about specific funding sources can be 

found in the Catalog of Federal Domestic Assistance, 

prepared by the Federal Office of Management and 

Budget and available in federal depository libraries

(CFDA, n.d.). It is the most comprehensive compilation 

of the types and sources of funding available.

7.2.1.2 State, Regional, and Local Grant and 

Loan Support

There are a number of sources for grant funding and 

loans for reuse projects. A summary of several state, 

regional, and local sources of grants and loans is 

provided in this section. 

State Revolving Fund

State support is generally available for WWTFs, 

WRFs, conveyance facilities, and, under certain 

conditions, for on-site distribution systems. A prime 

source of state-supported funding is provided through 

State Revolving Funds (SRF) loans.

The SRF is a financial assistance program established 

and managed by the states under general EPA 

guidance and regulations and funded jointly by the 

federal government (80 percent) and state matching 

money (20 percent). It is designed to provide financial 

assistance to local agencies to construct water

pollution control facilities and to implement non-point 

source, groundwater, and estuary management 

activities, as well as potable water facilities.

Under SRF, states make low-interest loans to local 

agencies. Interest rates are set by the states and must 

be below current market rates and may be as low as 0 

percent. The amount of such loans may be up to 100 

percent of the cost of eligible facilities. Loan 

repayments begin within 1 year of completion of the 

facility construction and are generally completely 

amortized in 20 years—although this differs from state 

to state. Repayments are deposited back into the SRF 

to be loaned to other agencies. 

States may establish eligibility criteria within the broad 

limits of the Clean Water State Revolving Fund 

(CWSRF). Basic eligible facilities include secondary 

and advanced treatment plants, pump stations, and 

force mains needed to achieve and maintain NPDES 

permit limits. States may also allow for eligible new 

and rehabilitated collection sewers, combined sewer 

overflow correction, stormwater facilities, and the 

purchase of land that is a functional part of the 

treatment process. Water conservation and reuse 

projects eligible under the Drinking Water State 

Revolving Fund (DWSRF) include installation of 

meters, installation or retrofit of water efficient devices 

such as plumbing fixtures and appliances, 

implementation of incentive programs to conserve 

water (e.g., rebates, tax breaks, vouchers, 

conservation rate structures), and installation of dualpipe distribution systems as a means of lowering costs 

of treating water to potable standards.

In addition to providing loans to water systems for 

water conservation and reuse, states can use their 

DWSRF set-aside funds to promote water efficiency 

through activities such as development of water 

conservation plans, technical assistance to systems on 

how to conserve water (e.g., water audits, leak 

detection, rate structure consultation), development 

and implementation of ordinances or regulations to 

conserve water, drought monitoring, and development 

and implementation of incentive programs or public 

education programs on conservation.

States select projects for funding based on a priority 

system, developed annually and subject to public 

review. Such priority systems are typically structured 

to achieve the policy goals of the state and may range 

from “readiness to proceed” to very specific water 

quality or geographic area objectives. Each state is 
Chapter 7 | Funding Water Reuse Systems

2012 Guidelines for Water Reuse 7-5 

allowed to write its own program regulations for SRF 

funding, driven by its own objectives with annual 

approval by EPA. Some states, such as Virginia, 

provide assistance based on assessing the 

community’s economic health, with poorer areas being 

more heavily subsidized with lower interest loans.

Further information on SRF programs is available from 

each state’s water pollution control agency.

Additional Local Funding Sources

Although the number of states that have developed 

other financial assistance programs or reuse projects 

is still limited, there are a few examples. Texas has 

developed a financial assistance program that includes 

the Agriculture Water Conservation Grants and Loans 

Program, the Water Research Grant Program, and the 

Rural Water Assistance Fund Program. There is also a 

planning grant program—Regional Facility Planning 

Grant Program and Regional Water Planning Group 

Grants—that funds studies and planning activities to 

evaluate and determine the most feasible alternatives 

to meet regional water supply and wastewater needs.

Local or regional agencies, such as the regional water 

management districts in Florida, have taxing authority. 

In Florida, a portion of the taxes collected has been 

allocated to funding alternative water resources 

including reuse projects, which have a high priority, 

with as much as 50 percent of the transmission system 

eligible for grant funding. Various methods of 

prioritization exist, with emphasis on projects that are 

benefit to multi-jurisdictional users. The Southwest 

Florida Water Management District states: 

“Our Cooperative Funding Initiative program 

has contributed to more than 300 reuse 

projects to help communities develop 

reclaimed water systems. Reuse grant funding 

since 1987 exceeds $343 million. Our 

Regional Water Supply Plan describes a 

District wide reclaimed water long-term goal of 

75 percent utilization of all wastewater 

treatment plant flows and 75 percent offset 

efficiency of all reclaimed water used”.

The California SWRCB administers the Water 

Recycling Funding Program (WRFP). The mission of 

the WRFP is to promote the beneficial use of 

reclaimed water (water recycling) in order to augment 

freshwater supplies in California by providing technical 

and financial assistance to agencies and other 

stakeholders in support of water recycling projects and 

research. The Plan establishes a strategic goal, sets 

program objectives, and identifies specific measures 

and targets for tracking program performance. 

Currently, the WRFP administers 49 construction 

projects and 33 facilities planning studies.

In 2006, Proposition 84 (The Safe Drinking Water, 

Water Quality and Supply, Flood Control, River and 

Coastal Protection Bond Act of 2006) passed for $5.4 

billion. Proposition 84 funds water, flood control, 

natural resources, park, and conservation projects. 

The bonds would be used to fund various projects 

aimed at 1) improving drinking and agricultural water 

quality and management; 2) preserving, restoring, and 

increasing public access to rivers and beaches; 3) 

improving flood control, and 4) planning for overall 

statewide water use, conveyance, and flood control.

For example, the DSRSD received a $1.13 million 

grant for the Central Dublin Recycled Water project 

from the California Department of Water Resources 

Proposition 84 Integrated Regional Water 

Management Implementation Grant Program. The 

$4.6 million project will bring recycled water to irrigate 

Dublin’s oldest neighborhoods, providing a rationingresistant water supply for schools, parks, and other 

valuable public landscaping. New distribution pipelines 

in Central Dublin will connect to existing recycled

water infrastructure that already serves other parts of 

the city.

In 2007, the state of Washington offered $5.45 million 

in grants to help local governments in the 12 Puget 

Sound counties reclaim water and help Puget Sound. 

The State Department of Ecology was responsible for 

carrying out the grant program under legislative 

directive to specifically aid Puget Sound. The highest 

funding priority was to be given to projects in watershort areas and where reclaimed water will restore 

important ecosystem functions in Puget Sound. 

7.3 Phasing and Participation 

Incentives 

Reclaimed water program phasing can account for the 

various limitations of the parties involved. Phasing is 

often necessary to extend capital expenditures over 

multiple years to better match the funding capacity of 

the water purveyor. Other limitations that may dictate a 

phased approach to reclaimed water programs include 

the impacts of establishing and connecting new 

services, evaluating whether existing potable water 
Chapter 7 | Funding Water Reuse Systems

7-6 2012 Guidelines for Water Reuse

users can be feasibly connected, educating new users, 

and the ongoing costs of regulatory requirements, 

such as annual water quality and backflow prevention 

valve testing. Phasing may also be considered for 

agencies that have not yet verified technical and/or 

financial feasibility of the planned reclaimed water 

system. Once initial phases have proven successful, 

constructing additional phases can be considered. 

Phasing can also be beneficial from the perspective of 

the new reclaimed water customer. The benefits of 

reclaimed water may be more immediately apparent to 

some types of users, while others may be more 

inclined to implement reclaimed water only after its 

success has been fully demonstrated. 

It is important to identify and obtain commitments from 

future reclaimed water customers before undertaking 

costs of design and construction. Those commitments 

will be critical to determining design capacity, facility 

sizing, and other decisions about future distribution 

branches. Securing these commitments often begins

by conducting an initial survey in a service area, 

followed by a formal written agreement. These 

agreements may include a memorandum of 

understanding, particularly for customers with 

significant capacity requirements, such as golf 

courses, large industrial customers, or agricultural 

operations. These commitments assure the long-term 

viability and financially sustainability of the project. 

A reclaimed water purveyor can employ participation 

incentives to help motivate users to convert to 

reclaimed water. Several variations of incentives have 

been used, including rate-based, capital-based, or 

subjective types of incentives. The rate structure for 

SAWS sets reclaimed water rates comparable to base 

potable water rates; however, incremental fees for 

water supply, stormwater, and aquifer management 

are not applied to the reclaimed water rate. For 

reclaimed water customers that transfer aquifer 

pumping rights to SAWS, that same volume of 

reclaimed water is priced at 25 percent of the basic 

reclaimed water rate. A combination of incentives can 

be used to entice the necessary users to convert to 

reclaimed water. Financial factors that should be 

considered may include the avoided or reduced costs 

of wastewater disposal, future expansion of potable 

treatment and/or storage facilities, and the higher 

costs of future potable supplies. 

Rate-based incentives can emphasize either positive 

or negative reinforcements. For example, a positive 

incentive could include a lower rate (volumetric unit 

price) for reclaimed water, e.g., less than 100 percent 

of the current potable rate. A negative incentive could 

include conservation-based increasing block rates that 

effectively penalize customers that have the types of 

summer peak usage that would benefit from using 

reclaimed water. 

Capital-based incentives include options to help pay 

for conversion costs. Some agencies in southern 

California have paid for and constructed on-site facility 

conversions, provided grants, or provided low or nointerest loans. At least one agency has used a 

surcharge that, in effect, sets the reclaimed water rate 

equal to the potable water rate until the loan is repaid. 

The Metropolitan Water District of Southern 

California’s Local Resource Program case study 

provides an example of a capital-based incentive [USCA-Southern California WMD].

Subjective incentives may have little cost impact to the 

reclaimed water purveyor but require effort to educate 

new reuse customers. Persuading them of the 

increased reliability and lower cost of reclaimed water 

is one approach. The increased nutrient levels that 

reclaimed water may provide are often important 

factors in obtaining commitments from agricultural 

customers. Most users can be convinced of the 

benefits of reclaimed water when there are no 

available potable supplies and reclaimed water is, 

therefore, their only option.

7.4 Sample Rate and Fee Structures 

There are several types of rate and fee structures that 

have been used for the recovery of reuse costs, 

including a fixed monthly fee, volumetric rates, 

connection fees, impact fees, and special 

assessments. Table 7-1 shows a comparison of rate 

types for a number of U.S. communities.

7.4.1 Service Fees

Service fees are typically charged to cover the cost of 

the meter or hose bib connection. The fee is typically 

related to the size of the meter or service line. 

Connection fees are also used as an incentive, with 

connection fees for those made in a specified time 

frame waived. The city of St. Petersburg Beach, Fla., 

charged a $250 connection fee that was waived if the 

connection was made within 1 year of availability.
Chapter 7 | Funding Water Reuse Systems

2012 Guidelines for Water Reuse 7-7 

Table 7-1 Comparison of reclaimed water rates

Community

Potable Water Rates 

First Tiers Only) Reclaimed Water Rates

Rate per

1,000 gal Use

Rate per

1,000 gal Use

% of Potable 

Rate

Tucson, AZ $2.19 1 - 15 ccf

$2.45 Variable on all uses

112%

$7.82 16 - 30 ccf 31%

Dublin San Ramon 

Services District, CA

$3.28

$3.48

Tier 1 Volume charge, first 

22,440 gallons $3.19 Flat rate volume charge

97% 

92% Tier 2 Volume charge, 

over 22,440 gallons

Eastern Municipal 

Water District, CA

$2.07

$3.79

Tier 1 Indoor use

Tier 2 Outdoor use

$0.80

$0.88

R-452 Non-Ag, Secondary, 

Disinfected-2009 21% of Tier 2

23% of Tier 2 R-462 Non-Ag, Tertiary, Disinfected, 

Filtered-2009

Glendale Water and

Power, CA $3.18 Commercial Rate $2.39 Nonpotable purposes 75% 

Irvine Ranch Water 

District, CA1

$1.62

$3.34

$5.78

Residential Detached 

Base Rate 5-9 ccf $1.44

$3.01

$5.20

Landscape Irrigation

Base Index 41-100% ET

89%

111%

111%

Residential Detached 

Inefficient Rate 10-14 ccf

Landscape Irrigation Inefficient Index 

101-110% ET

Residential Detached 

Excessive Rate 15-19 ccf

Landscape Irrigation Excessive Index 

111-120% ET

Los Angeles 

Department of Water 

and Power, CA

$4.77

Schedule C-First Tier

Jul-Sep High Season

1.42

1.76

Valley and Metro

West Side and Harbor

30% 

37% 

Boca Raton, FL $0.742 0 - 25,000 gal $0.449 0 - 25,000 gallons

Tiered rates per 1,000 gal 61%

Cape Coral, FL $3.81 0 - 5,000 gal

$0.0012

$9.50

$0.50

Res per lot sq. ft. multi-family

Fixed fee

Non-Res - per 1,000 gal.

13%

Orange County, FL $1.04

$1.39

0 - 3,000 gal

4,000 - 10,000 gal

$0.74 Variable on > 4,000 gal/month

71%

53%

St. Petersburg, FL $3.45 0 - 5,600 gal

$17.63

$10.10

$0.50

Unmetered - First acre

Unmetered > 1 acre

Metered**

14%

City of Tampa, FL $2.43

$2.82

0 - 5 ccf

6 - 13 ccf

$1.60 Variable on all uses

66%

57%

Cary, NC $3.60

$5.79

0 - 5,000 gal

0 - 15,000 gal

$3.60 Variable on all uses

100%

62%

El Paso, TX $1.94 Over 4 ccf $1.24 Variable on all use 64%

Hampton Roads 

Sanitation District, VA $4.00 Average rate for all uses $1.50 Variable on all uses 38%

Loudoun Water, 

Loudoun County, VA $1.82 Variable, non-peak rate $1.28 Variable, non-peak rate 70 %

San Antonio Water 

System, San Antonio, 

TX

$1.09

$1.63

Base volume charge at 90 

% annual average use $0.92

$0.99

Base Rate, first 748,000 gal 84 %

61 % Volume charge at 125 -

150% annual average use Seasonal Rate, first 748,000 gal

ccf = 100 cubic feet

1Irvine Ranch Water District employs a steep inclined rate based on watering in excess of the evapotranspiration (ET) rate.
Chapter 7 | Funding Water Reuse Systems

7-8 2012 Guidelines for Water Reuse

7.4.2 Special Assessments

Special assessments are established to defray the 

initial capital costs of a reuse system, primarily the 

distribution system. This type of assessment may be 

applied to those connecting to the reuse system or to 

all that have reuse system availability. Availability is 

typically defined as the distance to a nearby pipeline. 

The cities of Cape Coral and St. Petersburg, Fla., 

utilize special assessments for this purpose. Cape 

Coral has established service areas, with all of the 

residences within that area subject to a special 

assessment. St. Petersburg relies on a customer 

application process, with the majority of the owners in 

a specific area required to agree to the service. While 

many reuse systems are partially supported by their 

water or wastewater system revenues, the systems in 

these two communities are self-supporting.

7.4.3 Impact Fees

Impact fees have been used to recover the capital 

costs of water and wastewater systems from new 

customer connections. Included in the calculation of 

the impact fee are effluent disposal costs for 

wastewater, as well as the cost of the treatment 

system. A rational nexus is needed to justify the costs 

recovered from impact fees. A portion of the reuse 

system costs may be recoverable from either water or 

wastewater impact fees due to the ability to defer or 

reduce the costs of supplying water or wastewater 

service. Hillsborough County, Fla., has defined the 

benefit to water and wastewater systems in terms of 

additional capacity available due to the implementation 

of the reuse system. The decreased cost of capacity 

was estimated and identified as a revenue source for 

the reuse system (percent of impact fee). 

7.4.4 Fixed Monthly Fee

Fixed monthly fees are used for a variety of purposes. 

In some cases, actual use is not metered, and the 

operation and maintenance costs and/or capital costs 

are collected from this fee. There are several methods 

used to establish these fees, such as a cost per acre, 

a cost per acre-foot, a cost per pervious square feet, a 

cost per equivalent residential connection, a cost per 

meter size, or a cost per customer. When there is a 

combination of a fixed monthly fee and a volumetric 

rate, the fixed monthly fee may include the costs of 

administration and customer service only, or this 

portion of the fee may also include a portion of capital 

costs. This approach could then base the fixed 

monthly fee on a per customer basis, per meter size, 

or per equivalent residential connection. When there is 

only a fixed monthly fee and no volumetric rate, there 

is generally a basis that attempts to relate an 

estimated use to the fee. The costs per acre, acre-foot, 

or pervious square foot all provide a means of 

establishing use without actually metering the use. 

The city of St. Petersburg Beach, Fla., has a fixed 

monthly fee that is consistent for residential customers 

and a commercial fee that was calculated based on 

permeable acres. There is no volumetric metering. 

Another example of a fixed fee with volumetric rates is 

provided in the reuse rate study for Durham, N.C., 

where a combination of a fixed monthly fee and 

volumetric rates were recommended. The fixed 

monthly fee is designed to recover this wholesale 

reuse system’s capital costs, with the costs allocated 

per estimated capacity for each of three customers.

7.4.5 Volumetric Rates

Volumetric rates may be the primary fee, with either 

operation/maintenance and/or capital costs recovered. 

These rates may be charged per thousand gallons or 

per hundred cubic feet. The actual volumetric rates 

may differ per phase of connection. Initial reuse 

systems may offer incentives for early connections. 

This is specifically true when reuse is the primary 

means of effluent disposal. Bulk users, such as 

agriculture, golf courses, and industrial applications, 

have benefited from these early connection rates. 

These large volume users may also need rates that 

are competitive with the costs of groundwater use 

rather than potable water. Lee County, Fla., has 

established user fee rates for their large customers on 

this basis. 

Other variations on the volumetric rates exist when 

water is distributed in low versus high pressure 

systems. Such cases are typical for golf courses that 

utilize storage ponds, where the pipeline distributing 

reclaimed water does not require high pressure, since 

high pressure distribution systems also have higher 

pumping costs. Collier County, Fla. has rates that are 

set on this basis. Inclining blocks are also used to 

conserve a limited resource. Hillsborough County and 

Boca Raton, Fla., have established three tiers of 

inclining blocks. 

7.5 Developing Rates 

There are typically two methods used for developing 

reclaimed water rates. The rate either fully covers the 
Chapter 7 | Funding Water Reuse Systems

2012 Guidelines for Water Reuse 7-9 

cost of reclaimed water production, distribution, 

administration, and operation, or rates are lowered by 

subsidizing the cost from other sources.

Full cost recovery rates include the appropriate portion 

of capital and annual costs to plan, design, construct, 

administer, and operate a reclaimed water program. 

Capital costs include treatment, distribution, and 

possibly on-site facilities. The allocation of treatment 

facilities between reclaimed water and wastewater 

rates can be challenging, but it is generally accepted 

that facilities necessary for meeting NPDES discharge 

requirement levels are attributed to wastewater rates. 

Anything in addition to costs necessary to produce 

reclaimed water of a higher quality is attributed to 

reclaimed water rates. 

The annual costs for reclaimed water rates include 

everything necessary for treatment (as allocated 

above) and operation of a reclaimed water distribution 

system. Costs necessary to meet regulatory 

requirements, such as annual testing and site 

monitoring, should not be overlooked. Estimating the 

operating cost of a reclaimed water system involves 

determining those treatment and distribution 

components that are directly attributable to the 

reclaimed water system. Direct operating costs involve 

additional treatment facilities, distribution, additional 

water quality monitoring, and inspection and 

monitoring staff.

Often the current costs of constructing reuse facilities 

cannot compete with the historical costs of an existing 

potable water system. Hence, a full cost recovery 

calculation frequently results in rates higher than 

potable water rates. As discussed in Section 7.1, 

reclaimed water rates have historically been expected 

to be lower than potable water to incentivize current 

potable water users to convert to reclaimed water. 

Therefore, reclaimed water rates are often subsidized 

to reduce the rate at or below the potable water rate. 

There are many opportunities in the rate calculation for 

subsidies from other sources, some of which are 

described below: 

Potable water. Reuse reduces potable water 

demands, thereby allowing the deferral or elimination 

of developing new potable water supplies or treatment 

facilities. These savings can be passed on to the reuse 

customer.

Wastewater. Costs saved from effluent disposal may 

be considered a credit. Indirect costs include a 

percentage of administration, management, and 

overhead. Another cost is replacement reserve, i.e., 

the reserve fund to pay for system replacement in the 

future. In many instances, monies generated to meet 

debt service coverage requirements are deposited into 

replacement reserves. 

General and administrative costs. These costs can 

also be allocated proportionately to all services, just as 

they would be in a cost-of-service allocation plan for 

water and wastewater service. In some cases, lower 

wastewater treatment costs may result from initiating 

reclaimed water usage. Therefore, the result may be a 

reduction in the wastewater user charge. In this case, 

depending on local circumstances, the savings could 

be allocated to the wastewater customer, the 

reclaimed water customer, or both. 

Conservation. In California, replacement of potable 

water with reclaimed water can be applied toward the 

conservation goal of a 20 percent reduction by the 

year 2020. Therefore, funds set aside for a 

conservation program could be applied to the reuse 

program to subsidize the reclaimed water rate.

With more than one category or type of reclaimed 

water user, different qualities of reclaimed water may 

be needed. If so, the user charge becomes somewhat 

more complicated to calculate, but it is no different 

than calculating the charges for treating different 

qualities of wastewater for discharge. For example, if 

reclaimed water is distributed for two different irrigation 

needs with one requiring higher quality water than the 

other, then the user fee calculation can be based on 

the cost of treatment to reach the quality required. This 

assumes that it is cost-effective to provide separate 

delivery systems to customers requiring different water 

quality. Clearly this will not always be the case, and a 

cost/benefit analysis of treating the entire reclaimed 

water stream to the highest level required must be 

compared to the cost of separate transmission 

systems. Consideration should also be given to 

providing a lower level of treatment to a single 

reclaimed water transmission system with additional 

treatment provided at the point of use as required by 

the customer and consistent with local/state 

regulations. 
Chapter 7 | Funding Water Reuse Systems

7-10 2012 Guidelines for Water Reuse

7.5.1 Market Rates Driven by Potable 

Water

Reclaimed water rate structures and rate values are 

set by the utility through the utility’s governing council 

or, in the case of private utilities, the public service 

commission. Reclaimed water and potable water 

variable rates are typically expressed as dollars per 

thousand gallons, dollars per 100 ft3

, or dollars per acft. The dollar value of reclaimed water rates is typically 

based on the value of reclaimed water to those who 

have nonpotable water demands, such as for irrigation 

or industrial applications. 

Reclaimed water rates are at their lowest values when 

the availability of freshwater and/or reclaimed water is 

significantly greater than demand. As fresh and 

reclaimed water supplies tighten relative to demand, 

there is pressure on the utility to raise reclaimed water 

rates to encourage reclaimed water conservation so 

that increasing demands can be supplied. In some 

cases, water conservation pricing is used to further 

encourage efficient reclaimed water use. In areas with 

sufficient freshwater supply but limited wastewater 

effluent disposal options, reclaimed water is produced 

and applied to constructed wetlands, pastures, and 

irrigated areas to reduce effluent discharges to surface 

waters or near shore coastal areas. The reclaimed

water rates in these areas can be much lower than 

potable water rates and reclaimed water costs.

In some cases, reclaimed water is provided at no 

charge or at a nominal charge that does not recover its 

full costs. As a result, the full costs are recovered 

through wastewater customers, through water 

customers, or through state or federal subsidies. For 

many utilities, reclaimed water use provides significant 

benefits to other customers by providing an 

environmentally-safe alternative to wastewater effluent 

disposal, by reducing ground and surface water 

pumping, and/or by delaying the need for additional 

water supply well fields and water treatment plant 

facility capacity.

Nationally, reclaimed water rates as a percent of 

potable water rates range from 0 to at least 100 

percent. According to a survey by AWWA, the median 

reclaimed water rate charged by sampled utilities in 

2000 and 2007 was 80 percent of the potable water 

rate (AWWA, 2008). The median reclaimed water rate 

as a percent of the potable water rate did not change 

between the two survey years. However, the number 

of respondents in 2007 (30) was significantly lower 

than those in 2000 (109). Of the utilities surveyed in 

2007, 42 percent set their reclaimed water rate to 

encourage reclaimed water use, and 11 percent based 

their reclaimed water rate on the estimated cost of 

service. The town of Cary, N.C., Reclaimed Water 

System case study is an example of setting reclaimed

water rates at a level to compete favorably with 

potable water rates [US-NC-Cary].

Florida treats and uses more reclaimed water per day 

and per person than any state in the nation, with 

California running a close second (FDEP, 2011b). 

Florida has a long history of water reuse beginning 

with agricultural irrigation in Tallahassee in the mid1960s and the development of the city of St. 

Petersburg system in the late-1970s (Toor and Rainey, 

2009). Florida utilities charge a wide range of 

reclaimed water rates recovering from none to most of 

the reclaimed water costs, depending on the 

availability of freshwater supplies relative to demand. 

About 177 utilities provide irrigation water to residential 

and/or non-residential customers in Florida. Of these, 

104 utilities provide reclaimed water use for residential 

irrigation; for 94 of these utilities, the reclaimed water 

rate was compared to the potable water rate. For 

brevity, the evaluation included only the water rates of 

residential single-family customers.

According to Florida’s 2010 Annual Reuse Inventory, 

the median residential variable rate for reclaimed 

water was $0.80 per 1,000 gallons in 2010 for the 29 

utilities that did not include a flat rate in their rate 

structures. For the 49 utilities that collected a flat rate, 

the median flat rate was $8.00 per month per account, 

and the median variable rate was $0.31 per 1,000 

gallons. These utilities do not include the 16 that 

provided reclaimed water service to their residential 

customers at no charge.

For each of these 94 utilities, the ratio of the reclaimed 

water variable rate to the potable water variable rate 

times 100 was calculated to obtain a percentage 

comparison metric. The potable water variable rate 

chosen from each utility’s inclining block rate structure 

was the rate at 10,000 gallons of water per month. For 

two of these utilities, the potable water rate at 10,001 

gallons per month was used because it is the same 

rate as the reclaimed water rate. These rate values are 

thought to capture the cost of using potable water for 

irrigation. Potable water rates are those that were 
Chapter 7 | Funding Water Reuse Systems

2012 Guidelines for Water Reuse 7-11

implemented in either 2010 or 2011. The distribution of 

these percentages among the 94 utilities is provided in 

Table 7-2. 

Table 7-2 Utility distribution of the reclaimed water 

rate as a percent of the potable water rate for singlefamily homes in Florida

Percent Range

Number of 

Utilities

Percent of 

Utilities

0% 39 41%

1% to 5% 0 0%

6% to 10% 8 9%

11% to 20% 10 11%

21% to 30% 10 11%

31% to 40% 7 7%

41% to 50% 7 7%

51% to 60% 4 4%

61% to 70% 2 2%

71% to 80% 1 1%

81% to 90% 1 1%

91% to 99% 0 0%

100% 5 5%

Total 94 100%

Average percent 22%

Median percent 10%

Minimum percent 0%

Maximum percent 100%

(a) Reclaimed water rates for single-family residential customers 

by utility are from the Florida Department of Environmental 

Protection, “2010 Reuse Inventory,” Tallahassee, Fla., May 2011

(FDEP, 2011a). Sources of utility potable water rates at 10,000 

gallons per month for residential single-family customers: For 

utilities in the Southwest Florida Water Management District the 

source is in-house data provided by the district. For all other 

public utilities the sources are the individual utility web sites. For 

all other private utilities, the source is the Florida Public Service 

Commission, "Comparative Rate Statistics as of December 31, 

2010". Potable water rates are those implemented in either 2010 

or 2011.

The most common ratio of reclaimed water to potable

water rates is 0 percent, with 41 percent of utilities 

levying either no charge or just a flat charge for 

residential reclaimed water use. The second most 

common reclaimed water rate as a percent of the 

potable water rate is in the range of 11 percent to 30 

percent, and 20 utilities, or 22 percent, are in this 

category. Only 13 utilities, or about 13 percent, set 

their reclaimed water rate in the range of 50 percent to 

100 percent of the potable water rate. About 5 percent 

of the utilities charge the same variable rate for 

reclaimed water as they do for potable water (100 

percent). The average reclaimed water rate as a 

percent of the potable water rate is 22 percent and the 

median is 10 percent. All of these utilities collect a flat 

charge for potable water service that ranges from $2 to 

$25 per single-family connection per month. Of these 

utilities, 49 (or 52 percent) collect a flat charge for 

reclaimed water service that ranges from $2.50 to $25 

per connection per month. 

Given this comparison of flat and variable rates 

between residential potable water service and 

reclaimed water service, most Florida utilities designed 

their 2010 reclaimed water rates to significantly lower 

customer water bills when reclaimed water is used 

instead of potable water. Many nonpotable water users 

are not fully aware of the benefits that reclaimed water 

provides. User benefits of reclaimed water may 

include: 

 Having a guaranteed and reliable water supply

 Ability to conserve fresh water for their other 

uses 

 Ability to irrigate more frequently than if a 

traditional water source was used 

 Ability to reduce fertilizer applications 

 Ability to apply more water to the crop or 

landscape than with a traditional water source 

(Hazen and Sawyer, 2010) 

 Typically costs less than potable water

As nonpotable water users begin to understand the 

benefits of reclaimed water to their household or 

business, the amount of money they are willing to pay 

for reclaimed water will increase along with reclaimed 

water demand.

7.5.2 Service Agreements Based on Take 

or Pay Charges

There are many types of reclaimed water service 

agreements with varying complexity, covenants, and 

restrictions. A survey by the AWWA (2008) indicated 

that most utilities either recovered less than 25 percent 

of their operating costs or they did not know how much 

they were recovering. Service agreements and cost 
Chapter 7 | Funding Water Reuse Systems

7-12 2012 Guidelines for Water Reuse

recovery for utilities is a large part of the socioeconomic balance that is required by utilities to 

properly value a reclaimed water product. The high 

cost of treating wastewater is one of the reasons that 

utilities have historically not wanted to pass the entire 

cost of a system onto their reclaimed water customers. 

This situation is also prevalent in the costs of potable

water systems and is a water industry-wide concern 

for the future. 

Service agreements can be relatively simple with a 

single rate, but normally they are complex and multitiered, depending on water quality, supply and 

demand, specialized reuse districts, and peaking 

factors. For example, the Irvine Ranch Water District’s 

recovery costs include no less than nine different 

classes of commodity charges for nonpotable and 

reclaimed water. Service agreements that include full 

cost recovery for reclaimed water should be promoted 

because reclaimed water is a reclaimed and delivered 

product that inherently includes all the costs in the 

value chain, from point of water withdrawal to point of 

use. First and best use, in terms of a service 

agreement, is not a factor; all water is reclaimed, and 

reclaimed water performance should be rated on the 

basis of delivered water quality. Additionally, the 

service agreements can include cost recovery for 

meters, commodity charges, tiered rates, surcharges, 

seasonal use, and peaking factors, and may include a 

market analysis to assess supply and demand for a 

regional system. A schedule of rates for each service 

agreement should include terms and conditions, 

covenants and restrictions, water quality parameters, 

allocations by intended use or service sector, and a 

dispute resolution clause.

7.5.3 Reuse Systems for New 

Development 

Similar to ordinances that require the installation of 

roads, water systems, and sewer systems, municipal 

ordinances can also require installation of reuse 

systems for new developments. Where new 

development occurs on sizeable tracts of open land, 

requiring the installation of a reuse system is an 

efficient method to provide for facilities to deliver 

reclaimed water. Examples exist in the southwest 

where reclaimed water systems were installed years 

prior to reclaimed water becoming available. Typically, 

such systems are designed to serve irrigation 

demands for the common areas of the new 

development, such as median strips, green belts, and 

parks. Under such an approach, developers incur the 

cost of constructing the reclaimed water delivery 

system. The installation of a reuse system before or 

during development will be less expensive than doing 

so afterwards or as a retrofit.

7.5.4 Connection Fees for Wastewater 

Treatment versus Distribution

Typically, connection fees for reuse systems are 

limited to recovering the costs of transmission and 

distribution. Treatment costs are generally the 

responsibility of the wastewater utility that provides 

reclaimed water; the wastewater utility and its 

customers assume financial responsibility for treating 

the wastewater to applicable standards, whether for 

discharge or reuse. Thus, the connection fee for a 

reclaimed water meter is often the same as the 

connection fee for a potable water meter because 

reclaimed water is considered a water resource and 

often is distributed by the water utility just like potable 

water. The cost of wastewater treatment would not be 

part of such a fee. 

There are examples of utilities including the cost of 

reclaimed water treatment in their fees or splitting such 

costs with the wastewater utility. The reuse utility may 

be a separate agency that simply takes wastewater 

treated to discharge standards and provides the 

necessary extra level of treatment to produce 

reclaimed water. In that circumstance, connection fees 

would properly include treatment costs. Situations can 

also be found where treatment costs are split and any 

responsibility borne by the water utility could be 

included in the reuse connection fees. Each situation 

is unique, and various costs must be identified to be 

sure a nexus exists between the cost and the ultimate 

service being provided to end users.

The amount of the potable water connection fees must 

be considered when setting the reuse connection fees. 

If the reuse connection fee is higher than the potable

water connection fee, there will be less incentive for a 

user to choose reclaimed water over potable water, 

unless the reclaimed water is priced at a discount to 

potable water. This is the same concept that applies to 

setting reclaimed water rates. Thus, while it may be 

possible to justify higher reuse fees, practical 

considerations may dictate that such fees are set 

below cost.
Chapter 7 | Funding Water Reuse Systems

2012 Guidelines for Water Reuse 7-13

An excellent case study example of a city successfully 

expanding its reclaimed water system by managing 

customer concerns about connection fees is the city of 

Pompano Beach, Fla. [US-FL-Pompano Beach]. 

7.6 References

American Water Works Association (AWWA). 2000. 

Principles of Water Rates, Fees, and Charges (M1). 5th

edition. American Water Works Association. Denver, CO.

American Water Works Association (AWWA). 2007. Water 

Resources Planning, Manual of Water Supply Practices 

(M50), 2nd edition. American Water Works Association. 

Denver, CO.

American Water Works Association (AWWA). 2010. Water 

Rates, Fees and the Legal Environment. 2nd edition. 

American Water Works Association. Denver, CO.

American Water Works Association (AWWA). 2008. Water 

Reuse Rates and Charges - Survey Results. American 

Water Works Association. Denver, CO.

Catalog of Federal Domestic Assistance (CFDA). n.d. 

Catalog of Federal Domestic Assistance. Retrieved on 

August 23, 2012 from <https://www.cfda.gov/>.

Florida Department of Environmental Protection (FDEP). 

2011a. 2010 Reuse Inventory, Tallahassee, Florida.

Retrieved on August 23,2012 from

<http://www.dep.state.fl.us/water/reuse/inventory.htm>. 

Florida Department of Environmental Protection (FDEP). 

2011b. “Table of Reuse Flow per Capita for the Nine 

States that Reported Having Reuse in 2006.” Based 

on data from the Water Reuse Foundation 

National Database of Water Reuse Facilities Summary 

Report, 2006. Retrieved on August 23, 2012 from

<http://www.dep.state.fl.us/water/reuse/inventory.htm>. 

Government Finance Officers Association (GFOA). 2005. 

Governmental Accounting, Auditing, and Financial 

Reporting: Using the GASB 34 Model. Government Finance 

Officers Association. Washington, DC.

Hazen and Sawyer. 2010. Economic Feasibility of 

Reclaimed Water Use by Non-Utility Water Use Permittees 

and Applicants, Final Report, prepared for the Southwest 

Florida Water Management District, Brooksville, Florida, 

June 2010.

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.

Toor, G. S., and D. P. Rainey. 2009. “History and Current 

Status of Reclaimed Water Use in Florida.” Institute of Food 

and Agricultural Sciences, University of Florida, Soil and 

Water Science Department. Gainesville, FL.

Water Environment Federation (WEF). 2004. Financing and 

Charges for Wastewater Systems (MOP 27). Water 

Environment Federation. Alexandria, VA.

WateReuse Research Foundation (WRRF). 2009. 

Evaluating Pricing Levels and Structures to Support 

Reclaimed Water Systems, WRRF 05-001.WateReuse 

Research Foundation. Alexandria, VA. 

WateReuse Research Foundation (WRRF). 2006. An 

Economic Framework for Evaluating Benefits and Costs of 

Water Reuse, WRRF 03-006-02. WateReuse Research 

Foundation. Alexandria, VA.

WateReuse Research Foundation (WRRF). 2004. Water 

Reuse Economic Framework Workshop Report, WRRF 03-

006. WateReuse Research Foundation, Alexandria, VA. 
Chapter 7 | Funding Water Reuse Systems

7-14 2012 Guidelines for Water Reuse

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2012 Guidelines for Water Reuse 8-1 

CHAPTER 8 

Public Outreach, Participation, and Consultation

This chapter provides an overview of key elements of 

public involvement, which is critical to success of any 

reuse program (WRA, 2009), as well as several case 

studies illustrating public involvement and/or 

participation approaches to support successful reuse 

programs 

8.1 Defining Public Involvement 

Public outreach, participation, and consultation 

programs work to identify and engage key stakeholder 

audiences on planned projects that directly impact the 

population. Generally, effective public participation 

programs invite two-way communication, provide 

education, and ask for meaningful input as the reuse 

program is developed and refined. Depending on the 

project, public involvement can involve a range of 

types and levels of outreach, participation, and 

consultation. Some projects require only limited 

contact with a number of specific users. Others take 

an expanded approach to include formation of a formal 

advisory committee or an extensive campaign with 

multiple methods of public engagement.

Regulatory agencies often require some level of public 

involvement in water management decisions, and 

stakeholders are increasingly vocal about being 

involved in those decisions. This is strikingly different 

from the past when members of the public were often 

informed about projects only after final decisions had 

been made. Today, responsible leaders recognize the 

need to inform and consult with the public to obtain 

their values and advice about science, technology, and 

legal aspects. Advancing the understanding of water 

issues can facilitate real, workable, and implementable 

solutions tailored to meet specific needs.

Public information efforts often begin by targeting the 

most impacted stakeholders. Over time, as an early 

education base is built among stakeholders, the 

education effort then broadens to include the public at 

large. Regardless of the audience, all public 

involvement efforts are geared to help ensure that 

adoption of a selected water reuse program will 

communicate benefits and fulfill real user needs and 

generally recognized community goals, including 

public health, safety, and program cost.

Two-way communication cannot be emphasized 

enough. In addition to building community support for 

a reuse program, public participation can also provide 

valuable community-specific information to reuse 

planners. Community residents may have legitimate 

concerns that quite often reflect their knowledge of 

detailed technical information. In reuse planning, 

especially, where one sector of the public comprises 

potential users of reclaimed water, this point is critical. 

Several case studies highlight how prompt and regular 

communication and a collaborative spirit between 

utilities, regulators, the general public, consultants, 

and contractors led to project success [US-CASouthern California MWD], [US-FL-Orlando E. 

Regional], [US-NC-Cary].

8.1.1 Public Opinion Shift: Reuse as an 

Option in the Water Management Toolbox

Over the past decade, public dialogue about reuse has 

increased, particularly in communities of water 

scarcity, and there is greater general public knowledge 

about water reuse as an option. In cities in the states 

of Arizona, California, Florida, and Texas where water 

reuse is already occurring, a survey by the WRRF

found that 66 percent of respondents knew what 

reclaimed or recycled water is, 23 percent were not 

sure, and 11 percent were unaware (WRA, 2009). 

Research has shown that public involvement for water

reuse projects can result in a community having a 

more favorable collective attitude toward a project as 

its level of familiarity with water reuse increases 

(USBR, 2004). Proactive education and involvement 

programs that put water reuse into perspective and 

promote shared decision-making help to ensure that 

public understanding develops.

A study conducted by San Diego County Water 

Authority demonstrates a shift in public opinion about 

reuse in the community between 2004 and 2011 

(Figure 8-1). The percentage of respondents who 

“strongly oppose” using advanced treated recycled 

water as an addition to drinking water supply dropped 

from 45 percent in 2004 to 11 percent in 2011 (San 

Diego County Water Authority, n.d.). 
Chapter 8 | Public Outreach, Participation, and Consultation

8-2 2012 Guidelines for Water Reuse

Media coverage of high-profile water reuse projects 

has taken center stage in television and national 

newspapers. In 2011, USA Today ran a cover story 

about potable reuse in Big Spring, Texas. In 2012, the 

New York Times published a front page story titled “As 

‘Yuck Factor’ Subsides, Treated Wastewater Flows 

From Taps.” By engaging with the media and larger 

communities, water utility public outreach campaigns 

have encouraged the dissemination of more sciencebased information about the risks and benefits of 

reuse.

8.1.2 Framing the Benefits

The process of public engagement begins with clearly 

defining the problem: What is the driving reason for 

which people are being asked to make a change and 

investment? What are the options for solving it?

Equally important is discussion of the benefits: What 

will the community and the individuals that comprise it 

gain from each of the solutions? It is important to 

discuss how water reuse can be of value to the public 

and the contexts in which it can surpass other options 

for securing supply reliability and/or quality. Once the 

reuse options—including status quo—are fully 

explored, it is then appropriate to discuss the 

technologies at our disposal to address the potential 

risks associated with reuse. In the past, dialogue has 

focused on risks and the associated mitigating 

technologies rather than beginning from a 

collaborative problem-solving standpoint.

This focus on identifying benefits is stressed in the 

WRRF report “Best Practices for Developing Indirect 

Potable Reuse Projects” (Resource Trends, Inc., 

2004). The report concludes that, “Although a 

compelling value may be created with products or 

services, the customer or audience must perceive that 

benefit. When a meaningful problem is solved, the 

perception will likely be that the state of affairs has 

improved. This goal is why clearly stating the problem 

is so important.”

So what are the perceived benefits? In a 2009 survey 

conducted by the WRA in eight target U.S. cities, 

“Conserving water in my community” was the 

dominant benefit driver by a 4 to 1 margin (WRA, 

2009). Other key benefits that were found to be strong 

motivators were “positive impact on wetland, streams, 

and wildlife habitat;” and “irrigating crops without 

wasting water.” Other possible benefits ranked lower, 

e.g., “industrial/manufacturing use,” “groundwater 

replenishment,” and “conserving water in my 

workplace.”

Figure 8-1

Survey results from San Diego: opinion about using advanced treated recycled water as an addition to 

drinking water supply (2004 and 2011) (SDWWA, 2012)

12%

16% 18%

45%

10%

34% 33%

14%

11%

8%

0

5

10

15

20

25

30

35

40

45

50

Strongly Favor Somewhat 

Favor

Somewhat 

Oppose

Strongly 

Oppose

Unsure

Percentage

2004

2011
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-3 

8.2 Why Public Participation is Critical 

Over the past few decades people have come to 

expect or even demand information and engagement 

related to utility decision-making and initiatives. The 

intensity of people’s interest in having a role in public 

decisions parallels the potential for impacts on their 

health, security, and quality of life. Water recycling in 

all its forms does or can be perceived to impact all of 

these factors; thus, public outreach and involvement 

have become key components in the success of water

reuse programs. 

Public participation begins with having a clear 

understanding of why reuse needs to be implemented, 

the water reuse options available to the community, 

and the potential concerns related to each option. 

Once an understanding of possible alternatives is 

developed, a list of stakeholders, including possible 

users, can be identified and early public contacts may 

begin. Why begin engaging stakeholders before a plan 

is in place? It is important to get early adopters that 

stakeholders can look to and even access for 

questions or concerns. These community resident 

stakeholders can provide early indications regarding 

acceptance of the reuse program and where 

management and other implementation team 

members may need to shore up or spend time on 

additional information and outreach components. 

Beyond that, informed residents can help identify and 

resolve potential problems before they occur and 

develop alternatives that may work more effectively for 

the community.

8.2.1 Project Success

Involvement of the public in each stage of project 

planning can be a critical step in achieving a 

successful project. Hundreds of water reuse projects 

have been undertaken in the last two decades; many 

have succeeded and others have failed. Economic, 

scientific, and technical soundness have not always 

translated into public support. Some projects failed 

after millions of dollars had already been spent for 

development, design, and community involvement, 

with opposition groups filing lawsuits as a means of 

stopping them. Public opposition, where present, has 

included concerns about potential or perceived risks to 

human health and the environment, economic 

concerns such as the cost to produce the water, 

population growth and development, environmental 

justice and equity, and competing water rights. In 

some cases, it has taken the form of general rejection 

of reuse except as an “option of last resort” (USBR, 

2004). A 2001 AWWA Research Foundation Highlights 

Report, Public Involvement – Making It Work, stresses 

this approach: “Drinking water utilities must involve the 

public prior to implementing projects that affect the 

public. Understanding this principle will save utilities 

time and money through avoided litigation and project 

delays. It will also lay the foundations for establishing 

public trust and support for future projects” (CH2M Hill, 

2001).

8.2.2 The Importance of an Informed 

Constituency 

A public participation program can build an informed 

constituency that is comfortable with the concept of 

reuse, knowledgeable about the issues involved in 

reclamation/reuse, and supportive of program 

implementation. Ideally, community residents who 

have taken part in the planning process will be 

effective proponents of the selected plans. Having 

educated themselves on the issues involved in 

adopting reclamation and reuse, they will also 

understand how various interests have been 

accommodated in the final plan. Public understanding 

of the decision-making process will, in turn, be 

communicated to larger interest groups—

neighborhoods, clubs, and municipal agencies—of 

which they are a part. Indeed, the potential reuse 

customer who is enthusiastic about the prospect of 

receiving service may become one of the most 

effective means of generating support for a program. 

This is certainly true with the urban reuse programs in 

St. Petersburg and Venice, Fla. In these communities, 

construction of distribution lines is contingent on the 

voluntary participation of a percentage of customers 

within a given area.

8.2.3 Building Trust 

Trust lies at the core of people’s understanding, 

support, and acceptance of reclaimed water as a 

supply alternative. Unfortunately, the current social 

and political environment has resulted in a general 

lack of trust and confidence in utility service providers; 

both public and private. Public involvement provides 

opportunities to build trust, not only by fully and 

truthfully informing individuals within the community, 

but ideally by engaging them to share information, 

provide feedback, or contribute to utility decisions. 

Trust is earned over time by actions and not just 

words, by taking risks and sharing power. Early public 

engagement and continuing participation throughout 
Chapter 8 | Public Outreach, Participation, and Consultation

8-4 2012 Guidelines for Water Reuse

the project (and even beyond) provides greater 

opportunities to develop trusting relationships. “Trying 

to sell a completely designed project does not 

embrace the true spirit of the word communicate—

coming to a common understanding” (AWWA, 2008;

WEF, 2008).

The AWWA/WEF Special Publication Using Reclaimed 

Water to Augment Potable Water Resources provides 

a path through the process of fully engaging the public 

in exploring the needs and benefits of water recycling. 

While targeted at IPR, the ideas and processes in this 

publication are applicable to all forms of water reuse

(AWWA, 2008). 

8.3 Identifying the “Public” 

Outreach and engagement regarding increased 

recycled water use must encompass a diverse crosssection of the communities that are impacted or who 

believe the project has some effect on their interests. 

Utilities with successful reuse initiatives identify these 

communities early on and develop a strategy to 

provide them with information in a format that adds to 

the credibility of the communication and to hear and 

address their ideas and concerns.

There is no such thing as “the general public.” People 

belong to geographic, socio-economic, gender, and 

age groups. They belong to groups according to 

political ideology, social orientation, and recreation 

interests. From a marketing perspective, they are 

frequent fliers, homeowners, credit card holders, 

health food eaters, and vacation takers. The 

segmentation of America is prolific, so there are 

groups and magazines tailored to just about any issue 

or interest. When planning for public outreach related 

to reclaimed water use, this diversity needs to be 

considered.

Diversity should be considered from a variety of 

perspectives, including ethnic, demographic, 

geographic, cultural, professional, and political 

background. Outreach and engagement also should 

reach multi-cultural, multi-lingual, and multi-ethnic 

communities and organizations. Market research has 

shown that some ethnic groups mistrust the safety of 

water supplies and are wary of government much 

more than the general population. Working to build 

support within multi-cultural organizations that are 

already trusted in these communities can help build 

awareness and acceptance of a reuse project more 

effectively and quickly than doing so independently. 

Outreach to organized groups is as important as 

outreach to individuals, if not more so. Groups that are 

likely to have an interest in reclaimed water use 

include chambers of commerce and environmental 

organizations, as well as health advocacy groups, 

service organizations, homeowners associations, 

academia, and organized labor. Outreach and public 

participation could take significant effort and time 

upfront but will ultimately save time over the life of the 

project.

One particularly successful example of this 

inclusiveness is the diversity of outreach by the OCWD 

for its Groundwater Replenishment System. For 

several years, OCWD staff provided presentations to 

hundreds of community organizations and leaders in 

the diverse communities of Orange County before 

seeking their support. Sometimes this meant 

presenting to three or four groups in a single day. The 

process was rigorous and time consuming, but the 

utility was able to secure support from the majority of 

these organizations. Supporters were listed on the 

project website, in informational materials, and in other 

public forums. This far-reaching inclusiveness helped 

the Groundwater Replenishment System become a 

reality [US-CA-Orange County].

8.4 Steps to Successful Public 

Participation 

From the experience of reuse projects over the past 

decade, it is possible to develop a core set of 

behaviors common to successful public engagement. 

Those actions include the steps presented in this 

section:

 Begin with an assessment of the community 

and of the utility itself. 

 Determine early the level of public involvement 

that will be sought, including a preliminary list of 

potential stakeholders. 

 Develop and follow a comprehensive strategic 

communication plan that presents information 

clearly and anticipates long-term implications of 

reuse messages. 

 Gauge community and utility opinions and 

attitudes; assess trusted information sources 

and avenues for participation. 
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-5 

 Meet with community officials and leaders early 

and then regularly. 

 Engage neutral, credentialed outside experts, 

as potential spokespeople or evaluators while 

establishing the utility as the primary, credible 

source of information. 

 Engage the media, approaching every available 

information channel, including social media. 

 Involve employees and ensure they are 

informed with accurate, timely information. 

 Dialogue with the broader community of 

stakeholders directly through various means; 

understand opposition, and be proactive in 

responding. 

A 2003 Water Environment Research Foundation 

(WERF) report outlines a framework to help water 

utilities engage constructively with the public on 

challenging, contentious issues. While outlining 

principles for success, the report stresses that no 

checklist of “to-do's” exists for establishing public 

confidence and trust. Quite the opposite, the research 

suggests that a one-size-fits-all model cannot work 

because the most appropriate steps must be tailored 

to the specific context. The report provides an 

analytical structure that utilities can use to assess the 

community and design an appropriate approach 

(Hartley, 2003). 

Several case studies illustrate how public participation 

is tailored to meet the needs of the specific context, 

from formal outreach and involvement campaigns to 

simpler informational programs. In an environment of 

distrust in government, OCWD and the OCSD 

successfully partnered to build a potentially 

controversial 70 mgd (3,067 L/s) IPR project that 

garnered overwhelming public support and overcame 

the “toilet-to-tap” misperception [US-CA-Orange 

County].

In many communities, reclaimed water has been 

widely accepted with little to no opposition. In these 

contexts, public education may include tours and 

websites, but not require dedicated public relations 

staff or a formal public outreach and communication 

program [US-GA-Forsyth County]. In Big Spring, 

Texas, a new water reclamation plant was launched in 

2010 that blends reclaimed water with raw water 

supplies. Open and proactive communications with 

state regulators and the public have been keys to the 

project’s success [US-TX-Big Spring].

Another example of public support of reuse comes 

from Virginia. Reclaimed water has been successfully 

augmenting the drinking water supply for over three 

decades at the Occoquan Reservoir in Northern 

Virginia near Washington, D.C. Though first 

unintended, a newly-conceived framework set in 

motion the intentional, planned use of reclaimed water 

for the purpose of supplementing a potable surface

water supply. A number of hearings were conducted to 

explain what was to be implemented and to allow the 

public a venue to express their views. While the UOSA 

has had an active 30-year program to provide 

information on its website and tours to local students 

from grade school through college, a formal public 

outreach campaign has not been necessary [US-VAOccoquan]. 

8.4.1 Situational Analysis

Planning for successful public outreach and 

engagement should begin with an assessment of the 

community and of the utility itself. While there are 

models of successful outreach for water reuse

programs to emulate, the selection of specific public 

involvement approaches, strategies, and tools should 

be based on the specific attributes and conditions in a 

community. In combination, this is termed a 

“Situational Analysis.” In analyzing the community, it is 

important to assess factors such as: 

 The current political environment in which the 

project will be implemented

 Economic, social, and environmental issues that 

might indirectly become part of the debate and 

communication platforms

 Public awareness and knowledge of waterrelated issues and how these issues may be 

interconnected

 The history and reputation of the utility, 

particularly related to trust

 Potential supporters and opponents

 What people currently are seeing and hearing in 

the media, particularly related to water quality 

and health
Chapter 8 | Public Outreach, Participation, and Consultation

8-6 2012 Guidelines for Water Reuse

 The principal conduits people rely upon for 

information, and which of those they trust

Findings likely will vary among differing geographies 

and demographics within the community. It is 

important to tap into all of these using tools such as: 

 A review of recent media coverage and social 

media content

 Interviews with elected and appointed officials

 Sit-down conversations with “inherent” 

community leaders who, though not titled, are 

respected and listened to by local constituents

 Discussions with customer service staff

 Public opinion surveys and focus groups

The WateReuse guidebook Marketing Nonpotable

Recycled Water provides a strategic plan template for 

public outreach, as well as example market research 

results on the types of messages and modes of 

communication that would be most reassuring

(Humphreys, 2006). As an example, the San Diego 

County Water Authority conducts annual surveys 

within its service area to measure public knowledge 

and opinions of water issues and share the results with 

the public (San Diego County Water Authority, 2012). 

Equally important is an inward assessment of the utility 

to understand factors such as:

 The amount of connectivity with the community 

and its values

 Openness to engaging people who may express 

varied perspectives of the project as well as of 

the utility and its leadership

 Willingness to share decision-making authority

 Willingness and capacity to sustain the hard 

work of going out to inform and engage the 

community, including making presentations to 

diverse and potentially adversarial groups

 Ability and willingness of management to 

support these efforts over time, including 

resource allocation

8.4.1.1 Environmental Justice

Environmental justice is of critical concern not only 

when planning a reuse project, but also while involving 

the community in the educational process. 

Environmental justice issues are a result of either 

procedural or geographic inequity. Procedural 

inequities occur when there is no “meaningful 

involvement” of community or stakeholder groups. 

EPA defines “meaningful involvement” as the seeking 

out and providing for the affected community an 

“appropriate opportunity” to participate in the decisionmaking process, as well as providing the opportunity 

for the community to have input that will be considered 

and has the potential to influence the decision-making 

process. Geographic inequity issues arise when one 

portion of the community perceives, rightly or wrongly, 

that it is required to share a majority, or 

disproportionate share, of the impact from project 

siting, ultimate water application location (where the 

water is ultimately used), or potential decreases in 

property values. Geographic inequity concerns arise 

primarily where projects are situated in economically 

or historically disadvantaged areas. 

Respectfully and clearly acknowledging and 

addressing environmental justice issues is critical to 

success. The guiding principle of environmental justice 

is that no group of people should bear an unbalanced 

share of negative environmental impacts of a project 

or program, and all should have equal right to 

environmental protection. Insightful tools that can help 

utilities address the delicate and potentially volatile 

issues of environmental justice include EPA’s 

Environmental Justice Web site, EPA “Toolkit for 

Assessing Potential Environmental Justice 

Allegations”, and Executive Order 12898, established 

during the Clinton administration (EPA, 2004). 

Questions to ask with regard to the potential for 

environmental justice issues related to a project are:

 Is each social group in the community being 

treated fairly or the same as others?

 Is everyone receiving equal access to safe, 

reliable drinking water?

 Is everyone protected equally from health risks?

 Is any social group bearing the burden of a 

negative aspect of this project or program? 
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-7 

Engagement of leaders in minority and under-served 

communities provides an opportunity to better

understand their sense of the potential for 

environmental justice issues related to a water reuse

project to arise, and establishes another forum for 

public outreach and involvement.

8.4.2 Levels of Involvement

It is important to understand and align community 

member expectations for public participation with what 

a utility, municipality, or agency is actually willing to 

commit to and able to deliver. If the two are aligned, 

public satisfaction with both the process and the 

outcome can be enhanced.

The appropriate scope, complexity, and content of 

public involvement will vary according to the type of 

reuse proposed, the nature of the community, and the 

magnitude of the project. A project for median 

irrigation or industrial uses, for example, is likely to 

directly touch far fewer individuals and evoke less 

opposition and controversy than a project involving 

playground irrigation or indirect potable reuse. (Metcalf 

& Eddy/AECOM, 2007). All reuse projects, however, 

warrant a thoughtful, targeted, transparent, and truthful 

public sharing of information with customers and 

stakeholders, as well as associated opportunities for 

participation.

The concept of varying levels of participation is 

captured by the “Spectrum of Public Participation” 

developed by the International Association of Public 

Participation (IAP2). The spectrum designates five 

levels of involvement ranging from informing, which 

provides balanced and objective information to help 

people understand the problem as well as alternatives 

for resolving it, to empowering, in which the utility turns 

over final decision making or a significant portion of it 

to the public or a representative unit of that public. The 

IAP2 spectrum articulates a “promise to the public” 

associated with each progressive level of participation. 

For example, informing promises that the utility will 

help the public understand, while empowering

promises the utility will implement what the public 

decides (IAP2, 2007). 

It is important to determine early the level of 

involvement that will be sought, keeping in mind the 

willingness and capacity of the utility (particularly its 

leadership) to broadly share the decision-making 

power. Once a level of involvement has been publicly 

promised, it can be more damaging to renege on that 

promise than to have no public involvement at all. 

8.4.3 Communication Plan 

Regardless of project scope, it is critical to develop at 

the earliest possible stage a comprehensive strategic 

communication plan that identifies how the utility will 

present information and solicit involvement of 

stakeholders. This plan should pre-identify and provide 

for training for those who will speak on behalf of the 

project, especially. The plan must consider consistent 

messaging, including the long-term implications of 

reuse messages. The various references at the end of 

this chapter may be useful planning tools.

8.4.3.1 The Role of Information in Changing 

Opinion

To communicate with the public in a way that fosters 

public understanding, utilities must consider carefully 

the way information is presented. Two recent WRRF

projects provide valuable and surprising feedback for 

the water industry about public communication about 

potable reuse, but the lessons are applicable for any 

type of reuse project. WRRF 07-03: Talking about 

Water; Images and Phrases that Support Informed 

Decisions about Water Reuse and Desalination

illustrates that while some staunch opponents are 

unlikely to change in opposition, a significant portion of 

community members may change their opinion to 

favor reuse when provided clear information (WRRF, 

2011). Figure 8-2 provides data from focus groups 

where individuals were noted as being of one of three 

mind-sets according to their responses about drinking 

reclaimed water: “minded a little,” “don’t mind at all,” or 

“minded a lot” (WRRF, 2011). Participants were then 

provided information related to water reuse, including 

easy-to-understand technical details and graphics 

explaining the water purification process. Following

this information sharing, most of those who had 

“minded a little,” changed their opinion to “don’t mind 

at all,” though many had additional questions. Most 

who had indicated they “minded a lot” maintained that 

position.
Chapter 8 | Public Outreach, Participation, and Consultation

8-8 2012 Guidelines for Water Reuse

This research led to the conclusions that information 

presented to the public needs to be simple enough to 

understand yet technical enough to trust and that 

public communications should be treated as a 

dialogue that avoids technical jargon and acronyms. 

An interactive web-based urban water cycle was 

developed to assist in explaining reuse to the public in 

the context of urban water management. While 

potential users generally know what flow and quality of 

reclaimed water are acceptable for different 

applications, it is critical to ensure a common baseline 

understanding among the community about local water 

cycle. A water cycle glossary and informational videos 

have been put together by the WRA to assist in a 

holistic and contextual understanding of water reuse 

(A Thirsty Planet, n.d.). 

8.4.3.2 Words Count

WRRF 07-03 clearly demonstrated that the industry’s 

vocabulary and means of communicating with the 

public are not well understood or well received, often 

resulting in confusion and contributing to public 

mistrust or lack of acceptance of water reuse projects. 

The terms to describe reclaimed water produced for 

augmentation of drinking water supply that survey 

respondents found the most reassuring all described 

the very high quality of the water, and did not include 

the “re” prefix (reuse, reclaimed, etc.), as summarized 

in Figure 8-3. On the other end of the spectrum, the 

terms found least reassuring are the terms most often 

used by the water industry (WRRF, 2011).

This study also found that most participants preferred 

that reclaimed water quality be described by the uses 

for which it is suitable, rather than a grading system, 

degree or type of treatment, or type of pollutants 

removed. Earlier research speaks of people’s 

“visceral” aversion to human waste and the difficulty 

overcoming a perception of contamination (Rozin and 

Fallon, 1987 and USBR, 2004). However, WRRF 09-

01: The Effect of Prior Knowledge of 'Unplanned' 

Potable Reuse on the Acceptance of 'Planned' Potable 

Reuse demonstrated that when reuse options are 

placed into context of the water cycle’s de facto

“unplanned potable reuse,” there is higher acceptance 

of “planned potable reuse” (WRRF, 2012). When 

compared to the IPR options of continuing to use the 

current water supply (“business as usual”), blending 

reclaimed water in a reservoir, and discharging treated 

water upstream of a drinking water treatment facility, 

direct potable reuse was judged to produce the safest 

drinking water by 41 percent of focus group 

participants (Figure 8-4). 

Figure 8-2

Focus group participant responses: before and after viewing information (Source: Adapted From WRRF, 

2011)

0

10

20

30

40

50

60

70

80

90

100

Don’t mind at all Mind a little Mind a lot

Number of focus group participants

Before information

After information
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-9 

Figure 8-4

Focus group participants preferred “direct potable use” over “business as usual,” “blended reservoir,” or 

“upstream discharge” IPR options (WRRF 09-01)

16%

23%

20%

41%

Reuse Scenario Preference

SCENARIO 1: Business As Usual

SCENARIO 2: Blended Reservoir

SCENARIO 3: Upstream Discharge

SCENARIO 4: Direct Potable Use

Figure 8-3

Water reclamation terms most used by the water industry are the least reassuring to the public. (Selected 

data from WRRF 07-03 – refer to the report for the complete list of terms studied.)

0

10

20

30

40

50

60

70

80

Water that 

is purer 

than 

drinking 

water

Water that 

is a 

standard 

higher than 

drinking 

water

Very pure 

water

Purified 

recycled 

water

Reverse 

osmosis 

water

Repurified 

water

NEWater Recycled 

water

Reclaimed 

water

Respondents who feel the term is 

reassuring or very reassuring

Without information With information
Chapter 8 | Public Outreach, Participation, and Consultation

8-10 2012 Guidelines for Water Reuse

The study suggests that the public is less concerned 

about the source of the drinking water supply than 

about monitoring and reliability of the safety and taste 

of their drinking water. Additionally, positive 

terminology leads to early acceptance of reuse. The

water purification plant described in the study 

appeared to strongly influence people’s preference.

A 2010 WRRF study titled The Psychology of Water 

Reclamation and Reuse: Survey Findings and 

Research Road Map found that only 13 percent of 

respondents said they would be unwilling to drink 

certified safe recycled water. In this study, messages 

of “recycled water is safe” and “all water has the 

properties of recycled water” were tested—each 

showed an increase in willingness to drink certified 

safe recycled water [US-CA-Psychology] (WRRF, 

2010a). 

Taken together, this research emphasizes the 

importance of language in setting the context for 

people’s perceptions about reclaimed water. 

Outcomes of the studies include recommendations for 

practices and terminology related to water reuse that 

will facilitate rather than erode people’s ability to 

understand and accept reused water as a safe and 

reliable water supply option. These include:

 Facilitate Understanding: Focus groups 

demonstrated that simple and easy-tounderstand information results in increased 

knowledge and acceptance of water reuse. At 

the same time, materials should not be overly 

simplistic. People want more in-depth 

information about water, as opposed to general 

information (WRRF, 2011). This result supports 

the benefit of informing people early in a reuse 

initiative, with information specific to the project 

being proposed. 

 Forget the Past: Reclaimed water is best 

presented in terms of its suitability for specific

uses, rather than its source.

 Emphasize Purity: The word “pure” and its 

derivatives help reassure people that the water 

is safe.

 Show that it is Integral to the Cycle: Water 

reuse is best presented in the context of the 

complete water cycle, setting the framework for 

people to understand the truth that all water is 

recycled. 

 Avoid Jargon: Many terms common to water 

utility professionals (flocculation, primary 

treatment, effluent) are obscure to most people. 

It’s important to explain the purification process 

and its outcomes in clear, readilyunderstandable terms. Some people perceive 

highly technical terminology as an attempt at 

obfuscation, which serves to erode rather than 

engender trust.

 Use Pictures: Graphics and pictures that 

clearly (and even cleverly) illustrate the 

technical steps of the water treatment process 

help people to understand and believe in the 

technology behind water purification. 

 Present Analogies: Comparisons can help 

people better understand and evaluate risk. 

Examples given include the explanation that 

“Wastewater is mostly water—a 53-gallon drum 

of it contains only about one tablespoon of dirt.” 

Similarly, researcher Shane Snyder noted in a 

Congressional hearing, “The highest 

concentration of any pharmaceutical compound 

in U.S. drinking waters is approximately 5 

million times lower than the therapeutic dose 

and that ...one could safely consume more than 

50,000 8-ounce glasses of this water per day 

without any health effects.” (Snyder, 2008). 

Another useful study is WRRF 09-07 - Research 

Update: Risk Assessment Study of PPCPS in 

Recycled Water to Support Public Review

(WRRF, 2010b).

 Tell It Like It Is: Terminology commonly used 

by the industry can get in the way of public 

understanding and acceptance of reclaimed 

water. The terms “constituents of emerging 

concern,” “trace organic compounds,” and 

“microconstituents,” are alternative terms to 

identify a number of anthropogenic chemical 

compounds that have been detected in water or 

wastewater, generally at very low levels, but 

that are not commonly regulated. While experts 

struggle to identify this category of constituents 

with an accurate term (as described in Chapter 

6), these terms can be confusing or alarming to 

the public. The term “emerging” is likely to 

increase a person’s sense of worry, connoting 

this not only exists, but is prone to become 

larger or more virulent. Use of the word 

“concern” expresses that this is something that 
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-11

should be a cause for apprehension. Alternative 

terms have been proposed, categorizing them 

by end use (e.g., pharmaceuticals, personal 

care products, flame retardants), by 

environmental and human health effect, if any 

(e.g., hormonally active agents or endocrine 

disrupting compounds), or by type of compound 

(e.g., chemical vs. microbiological, phenolic vs. 

polycyclic aromatic hydrocarbons). The sheer 

array of different types of compounds can 

likewise cause confusion and are not well 

understood by the general public.

The term endocrine disruptors can be misinterpreted 

as having proven implications for human endocrine 

systems, whereas current evidence is limited to 

disruptions in frogs and fish. A report by WERF, 

Communication Principles and Practices, Public 

Perception and Message Effectiveness provides 

guidance on effective risk communication practices, 

particularly around TrOC (Deeb, 2010). The report 

suggests a less stigmatizing term for most of these 

constituents is “pharmaceuticals and personal care 

products” with the added words “and other unregulated 

constituents” to broaden the term to be inclusive of a 

wider array of constituents. 

Common terms like “toilet-to-tap” tend to resurface in 

people’s minds the link between reclaimed water and 

wastewater. Still, perpetuation of such words and 

phrases often is beyond the control of those proposing 

reuse projects; it is, in fact, in the control of those most 

commonly perpetuating the words and phrases, 

namely the media and project opponents. The utility 

should be prepared and ready (and willing) to clarify 

the inaccuracy of “toilet-to-tap” and similar terms, 

either by explaining that reuse is but one segment of 

the ongoing water cycle or by stressing the multiple 

intervening treatment steps between toilet and tap. 

While a great deal is now understood around how to 

build public understanding and involvement in reuse, 

some questions remain, and are described in the case 

study [US-CA-Psychology] originally reported by 

WRRF (2010a). 

8.4.3.3 Slogans and Branding

As emphasized in the previous section, the choice of 

slogan for a reuse campaign must be easy to 

understand and must communicate the benefits that 

resonate most with the target audience. WRRF found 

that “Water... it’s too valuable to be used just once” 

was the branding statement that was preferred by 

more than a 2 to 1 margin over all alternatives in their 

eight-city stakeholder survey (WRA, 2009). Since 

public understanding and attitudes about water reuse 

varies greatly by location and is dynamic, it is 

important to understand and stay current on 

stakeholder attitudes and beliefs about key benefits in 

a given location. 

8.4.3.4 Reclaimed Water Signage 

One undervalued, and often overlooked, method for 

communicating the benefits of water reuse to the 

public is the posted signage provided to reclaimed 

water irrigation customers. As just described, the 

terminology presented on the sign can convey the 

message of the benefits of reuse, while properly 

advising the community on the type of water being 

used for irrigation. Many states still require a symbol 

with drinking glass and a slash with text “Do Not 

Drink,” but also allow the inclusion of more positive 

language as shown in the adjacent signage example.

Some states have specific requirements for reuse 

signage. An additional discussion on signage is 

provided in Chapter 2. An example of terminology 

used by the Cucamonga Valley Water District, Calif., 

(CVWD) is shown in Figure 8-5. The signage 

emphasizes the benefits of using recycled water for 

irrigation (i.e., supporting conservation) through the 

use of large centered text. The advisory language, 

shown in smaller text on the lower right hand corner, is 

still present but is not the focus of the sign. This simple 

choice in word selection and imaging results in a 

positive message being conveyed to the audience and 

eases public concerns. 
Chapter 8 | Public Outreach, Participation, and Consultation

8-12 2012 Guidelines for Water Reuse

8.4.4 Public Understanding

To build an informed constituency, pre-conceived 

notions about reclaimed water and its risks must be 

identified and addressed. In water reuse, a challenge 

may lie in the difference between the technical experts’ 

understanding and the lay public’s perceptions of 

water reuse projects.

8.4.4.1 Perception of Risk

In general, the public tends to perceive risks differently 

than scientists schooled in the statistical analysis of 

risk. A growing body of research is examining the 

factors that explain the public’s perceptions of risk and 

thus influence decision-making and project 

implementation. Researchers in this area of study are 

finding that the range of factors that underlie the 

public’s perception of risk is very large. Technical 

information and public participation can influence the 

public’s response to those factors, but it is only one 

influence and may not be sufficiently persuasive on its 

own. Other factors that influence the public’s 

perception of risk associated with water reuse include:

 The cluster of mental pictures or associations 

that follow mention of the words “wastewater,” 

“reclaimed water,” or “reuse water”

 The way in which different groups within the 

general public rank and evaluate other risks 

relative to water reuse, such as sunbathing, 

caffeine, a poor diet, or driving without a 

seatbelt

 The baseline knowledge that different groups 

already possess about causality or different risk 

factors associated with disease-specific 

outcomes

 The level of trust in which the public holds the 

agency or body responsible for managing a risk

Given the importance of each of these variables to 

understanding perceptions of different health and 

environmental risks and to communicating effectively 

about reuse, public information campaigns must 

consider:

 Perceived risk

 Effect and image

 Language and stigma

 Mental and cultural models (context)

 Trust

As previously mentioned, a useful study is WRRF 09-

07 - Research Update: Risk Assessment Study of 

PPCPS in Recycled Water to Support Public Review 

(WRRF, 2010b).

8.4.4.2 Trusted Information Sources 

Survey research conducted by individual utilities 

continues to indicate that the public has a greater level 

of trust in opinions about potable reuse projects 

provided by scientific experts. A WRRF research study 

found that independent (e.g., university-affiliated) 

scientists are the most credible source of information 

on recycled water, followed by state and federal 

government scientists (WRRF, 2010a). Hired actors, 

neighbors, and employees of private water-related 

companies are least credible, according to this study 

[US-CA-Psychology]. The WRRF 09-01 study (WRRF, 

2012) resulted in slightly different conclusions about 

which sources of information about reuse the public 

trusts most to provide information about reuse 

(Table 8-1). 

In this study, respondents from the United States and, 

to an even greater degree, from Australia, identified 

regulators as the most trustworthy source of reclaimed 

water information. Regulators were chosen by more 

people than consultants, professors, doctors, and local 

water agency spokespeople.

Figure 8-5

CVWD encourages its wholesale customers to 

promote the notification of water reuse benefits 

(Photo credit: Miguel Garcia)
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-13

Because trusted sources can vary from community to 

community, state to state, and country to country—as 

evidenced when comparing the WRRF (2010a) and 

WRRF 09-01 results—it is best to conduct a public 

opinion survey in each community where water reuse 

is being considered.

8.4.5 Community Leaders

Public involvement early in the planning process, even 

as alternatives are beginning to be identified, allows 

ample time for the dissemination and acceptance of 

new ideas among the constituents. Public involvement 

can even expedite a reuse program by uncovering any 

opposition early enough to adequately address 

concerns and perhaps modify the program to better fit 

the community. As mentioned previously, engagement 

of leaders in groups with specific interests or from 

under-served communities provides opportunities to 

understand the needs and concerns of the community 

as a whole.

Further, because many reuse programs may ultimately 

require a public referendum to approve a bond issue 

for funding reuse system capital improvements, 

diligently soliciting community viewpoints and 

addressing any concerns early in the planning process 

can be invaluable in garnering support. Engaging 

policy makers, educating them on the facts about 

reuse, and gaining their acceptance can be a critical 

component to public involvement. By providing policy 

makers with proper education on reuse, they will be 

prepared with facts and tools should stakeholders call 

them or their representatives with questions or 

concerns. 

8.4.6 Independent Experts

To demonstrate that the utility is seen as taking 

community concerns seriously and as the primary, 

credible source of information, the outreach program 

can target the use of stakeholder advisory groups or 

neutral experts to inform the planning and evaluation 

process.

8.4.6.1 Advisory Groups

Making decisions about recycled water projects, 

especially potable reuse projects, can be challenging 

when different interest groups are involved. One way 

to address those challenges, as well as to ensure that 

community values and diverse opinions are 

considered, is to establish an advisory group or 

taskforce composed of representatives of the range of 

perspectives in the community. The community 

advisory group provides a forum to enable 

stakeholders to enter into a dialogue with each other 

and even develop recommendations related to a 

specific project. There is one key element to consider 

before deciding whether a community advisory group 

should be established: early agreement on the group’s 

role in the decision-making process and/or work 

product. An advisory group should clearly understand 

what they are being asked to do in context of the 

project, and each group should have and agree to a 

mission statement and principles of participation. This 

ensures the group members, as well as utility staff and 

decision-makers, clearly understand what is expected 

of the group. Further it is critical to make sure that 

human and financial resources are available to support 

the group process, an independent facilitator is 

retained to guide the group process and ensure its 

independence, group participants are selected to 

represent various community perspectives needed by 

the project team, and also that adequate time is 

allocated for the group to meet and develop

recommendations and input. 

There are several benefits that can accrue from a 

properly designed and administered community 

advisory group:

 All stakeholders can gain an understanding of 

each other’s perspectives.

Table 8-1 Focus group participant responses – most trusted sources (Source: Adapted from WRRF, 2012)

Source

U.S. Respondents

(n=302)

Australia Respondents

(n=349)

Number Percentage Number Percentage

Regulators 130 43% 215 62%

Consultants 27 9% 13 4%

University professors 42 14% 36 10%

Medical doctors 56 19% 48 14%

Local water agency spokesperson 47 16% 37 11%
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8-14 2012 Guidelines for Water Reuse

 Stakeholders can develop a better 

understanding of the decision-makers’ dilemma 

in trying to satisfy groups holding differing 

positions. 

 Meetings of the group allow time for members to 

gain a deeper understanding about technical, 

fiscal, and community issues that must be 

considered. 

 Participating in a series of meetings on a 

specific topic can help build trust and also result 

in ownership of recommendations by the group 

members. 

 The group itself, or its individual members, can 

become a legitimate voice in the community for 

supporting a decision. 

At the University of California, Santa Cruz campus, 

future enrollment growth will result in a 25 percent 

increase in water demand. A campus workshop 

involving faculty was held to rank a range of potential 

reuse projects. Steps are now in place to help offset 

the potential increase in demand [US-CA-Santa Cruz].

8.4.6.2 Independent Advisory Panels 

Another important group to consider is an independent 

advisory panel composed of science, health, water 

quality, and other technical experts. Such independent 

advisory panels have multiple benefits for utilities 

seeking to implement or expand water recycling. Panel 

members provide access to a broad range of 

worldwide technical and scientific expertise. They offer 

an unbiased review of proposed actions and activities, 

advancing sound public-policy decisions. And, relative 

to public outreach and information, the panels offer 

highly expert and impartial validation of the project’s 

soundness and safety. 

Utilities can use a number of independent research 

organizations to convene and manage an independent 

advisory group, which further validates their 

independent evaluation of the project. The utility 

should recognize from the start that engagement of the 

panel and work to support its studies is likely to add to 

the time commitment and cost of the project. Like all 

aspects of public engagement, it is a matter of 

weighing costs and benefits. The utility will want to 

carefully outline the purpose and specific focus areas 

of the panel, which will help to establish its 

membership, guide its work, and avoid unnecessary 

costs. 

Reports from independent advisory panels can serve 

many purposes, including suggesting technical 

enhancements to the project design; identifying costsaving measures; serving as a focal point for public 

information; providing independent corroboration of the 

project’s validity and safety, particularly to skeptics; 

and serving as a resource to regulators and oversight 

agencies. While the independent advisory panel’s 

report will be technical in nature and will be read in its 

entirety by the project team and those with technical 

interests, developing an accompanying executive 

summary is recommended, so that technical findings 

are accessible and easily understood by a lay 

audience. 

8.4.6.3 Independent Monitoring and 

Certification

Several reuse projects have benefitted from the use of 

monitoring and certification programs to build public 

trust. The city of Tucson has augmented its reuse 

water service inspection program to build public trust. 

The program includes testing for cross-connections, 

ordinances, and inspector training and certification 

programs [US-AZ-Tucson]. Tossa de Mar in Spain is 

one of the leading cities in Costa Brava to recognize 

the benefits of turning wastewater into reclaimed water 

after the region suffered from a prolonged drought. 

The water supply and sanitation agency promoted a 

high-quality branding through their website, the 

municipality website, and Facebook [Spain-Costa 

Brava].

King County, Wash., is constructing a new WWTF 

designed to produce Class A reclaimed water, which is 

safe to use for irrigating food crops. To gain customer 

confidence and to confirm suitability to end users, King 

County partnered with the University of Washington to 

conduct research on the safety and efficacy of Class A 

reclaimed water use [US-WA-King County].

As customers connect to the reclaimed water system, 

outreach is undertaken to inform users of safe and 

proper applications of reclaimed water. Many states, 

such as Florida, include customer education as a 

reuse permit requirement. 
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-15

8.4.7 Media Outreach 

Local media play an integral role in shaping public 

opinion about projects. Numerous case studies 

demonstrate the value of media as an outreach 

conduit regarding water reuse, with the added 

credibility of originating from a neutral third party. To 

establish effective media relations, several BMPs will 

help to create a positive working environment.

 Identify specific reporters who will likely cover 

the topic on a regular basis and take time to 

provide them with background information when 

they are not facing a deadline in order to 

develop longstanding relationships and foster 

more accurate reporting.

 Identify, internally, who will speak regularly with 

the media and provide them with training on 

how to explain the project in concise, easy-tounderstand statements that will, in turn, become 

good quotes.

 Determine local media preferences for 

communication and make use of the preferred 

resources, including formal news releases, 

Twitter, Facebook, email, phone, fax, and inperson communication.

 Identify local newspaper editorial boards and 

begin to educate them on the benefits of reuse 

early on. These are different individuals than the 

news reporters.

 Be responsive and direct in answering media 

questions. A reporter who knows that he/she 

can come to a source for direct answers, even 

to difficult questions, will develop a respectful 

relationship with that source.

 Think about ways to help reporters tell the story 

visually; consider illustrations or props and plan 

for short-term successes (i.e., landscaped 

medians) that can be showcased. Many media 

outlets can take files directly from an in-house 

graphic artist.

 Humanize the story rather than presenting all 

details on a clinical level. This also helps to 

humanize the organization. Reporters will also 

look for other third-party sources to interview. 

Be ready to suggest positive interview 

candidates and story ideas.

 If something negative happens with a project, 

consider the facts that are most likely to go 

public and be direct, never evasive, in 

presenting the facts.

Media coverage of the city of San Diego’s Water 

Purification Demonstration Project with the potential 

for reservoir augmentation is a prime example of how 

a utility can work with the media to present more 

accurate information about a reuse project. In the late 

1990s, the San Diego Union-Tribune, San Diego’s 

largest regional newspaper, editorialized against water 

reuse in any form, particularly potable reuse. The city 

of San Diego conducted the Water Reuse Study, 

which resulted in a community group endorsing the 

concept of reservoir augmentation as the most 

sensible use of the recycled water the city plants were 

producing. This study laid the groundwork for providing 

more factual information to reporters, culminating in an 

article by a Union-Tribune writer that very accurately 

described the purification processes that would be 

used at the city’s Advanced Water Purification Facility, 

the cornerstone of the Demonstration Project. Four 

months later, the paper published an editorial titled 

“The Yuck Factor – Get Over It.” Thanks also to the 

progress made on the potable reuse project in Big 

Spring, Texas, television and national newspapers 

began to cover the topic in a more factual way during 

2011, including a cover story in USA Today. In 2012, 

the New York Times published a front-page story titled 

“As ‘Yuck Factor’ Subsides, Treated Wastewater 

Flows From Taps.” Many hard-working water utility 

public outreach staffers have spent countless hours 

talking to reporters and encouraging more sciencebased information about potable reuse, a trend that 

will hopefully continue.

8.4.7.1 New Media Outreach Methods – Social 

Networking

In today’s dynamic environment, it is important that 

utility professionals use the most effective and 

dynamic communication tools available to connect with 

stakeholders and communities on an ongoing basis. In 

a 2012 paper titled “Social Media Demonstrates Their 

Worth for Utilities and Their Stakeholders,” the authors 

present the value that social media can provide as a 

utility communication tool and describe how D.C. 

Water has completely integrated social media 

elements into a larger communications strategy 

(Peabody et al., 2012).
Chapter 8 | Public Outreach, Participation, and Consultation

8-16 2012 Guidelines for Water Reuse

Social media should not be ignored. In today’s 

dynamic environment, social media can provide 

interesting insights into the stakeholder population, 

can offer early alerts to opposition, and can provide 

direct contact to stakeholder groups. A caution, 

though, is the reality that effective use of social media 

requires commitment of staff resources and time that 

is continuous and can become significant, particularly 

if there is controversy or opposition surrounding a 

project. Ignoring or failing to keep current with the flow 

of conversation in such circumstances can be 

detrimental to the project and the organization's 

reputation. 

8.4.8 Involving Employees

Employees comprise another often-overlooked but 

highly important component of the public. People 

working for the utility (as well as for associated 

organizations, such as departments within the same 

city) often are questioned by family and neighbors and 

are seen as a reliable source of information about 

projects and initiatives. Special, targeted efforts to 

inform and engage this specialized audience is a way 

to ensure they have accurate, timely information to 

convey to others. It also provides the opportunity for 

them to bring back ideas and concerns they hear from 

others. 

8.4.9 Direct Stakeholder Engagement

As described in Section 8.1, public involvement often 

begins by targeting the most impacted stakeholders, 

with the outreach effort broadening to include the 

public at large over time. For instance, a community 

may work closely with golf course owners and 

superintendents to introduce reclaimed water as a 

resource to keep the golf course in prime condition, 

even at times when other water supplies are low. This 

small, informed constituency can then provide the 

community with a lead-in to other reclaimed water 

options in the future. Golf course superintendents 

spread the word informally, and, as golfers see the 

benefits, the earliest of education campaigns has 

subtly begun. Later, the same community may choose 

to introduce an urban system, offering reclaimed water 

for irrigation use. 

8.4.9.1 Dialogue with Stakeholders

A broad range of involvement techniques are available 

for direct dialogue with stakeholders, including: 

surveys, public information programs, public meetings, 

workshops, interviews with key stakeholders, 

community events, presentations, and regular eupdates (Metcalf & Eddy/AECOM, 2007). It is critical 

that language translation of informational materials is

incorporated into the outreach strategy to ensure that 

all stakeholders within the utility’s diverse community 

of interests will benefit from outreach and public 

participation opportunities.

8.4.9.2 Addressing Opposition

Opposition frequently is aroused by prospects of water 

reuse, most often when a project involves children 

and/or use of reclaimed water as a potable source. As 

part of public involvement, it is critical to anticipate and 

be prepared to address opposing viewpoints. In 

developing groups for public involvement, it is 

preferable for the utility to include opponents as part of 

the mix of participants. This will help bring to the 

surface issues that need to be addressed and also 

may help to make the opposing individuals more 

informed and more comfortable with reuse.

People voicing opposition to reclaimed water projects 

most often cite health concerns, though sometimes 

there are other underlying drivers of opposition. For 

example, opposition to urban growth or specific 

political agendas has underlying factors masked in 

health-issue opposition to projects. A 2011 WRRF

study conducted in Arizona (WRRF 06-016-01) found 

that survey respondents’ views on the acceptability of 

reclaimed water for various uses was influenced by 

their perception of the desirability of growth in their 

community (Scott et al, 2011).

Opposition can surface at any point in the project’s 

lifecycle. In Pompano Beach, objections to 

development were one source of opposition to reuse 

[US-FL-Pompano Beach]. The potential for political 

opportunism during an election cycle underscores the 

importance of developing a public engagement 

program where community and stakeholder 

involvement occurs at all stages of the project so that 

stakeholders are involved in the decision-making 

process and the community and politicians know about 

and accept the project. Project timing must be 

considered in the broader sense to avoid political 

opportunism, if possible (USBR, 2004). When met with 

opposition, it is important to:

 Include both individuals who might support the 

utility’s position as well as those who might 

oppose it when forming participation groups.
Chapter 8 | Public Outreach, Participation, and Consultation

2012 Guidelines for Water Reuse 8-17

 Be prepared to respond promptly and calmly to 

misinformation.

 Be prepared to address opposition with clear, 

readily-comprehensible information and 

illustrations.

 Get support in writing if someone voices such 

support.

8.5 Variations in Public Outreach

Public outreach can vary, depending on the project 

itself and/or the community it will serve. Decisionmakers may choose to test a novel approach (whether 

technological or regulatory) through demonstration 

projects, in order to demonstrate reliability to 

constituencies. While demonstration projects can add 

time to the overall implementation schedule of a reuse 

project, public buy-in may be enhanced if participation 

is built from the demonstration phase and an 

appropriate, tailored solution can be constructed from 

all available approaches, rather than succumbing to 

the temptation to simply copy existing ‘proven’ 

approaches (e.g., the treatment train of Orange 

County). In some cases, a demonstration project may 

be an appropriate step prior to setting new regulation, 

rather than the reverse.

In the case of King County, Wash., in addition to 

sharing data with the public on the quality of the 

reclaimed water and the crops irrigated by it, 

luncheons and tastings were held at the end of each 

year’s research. The staff of the King County 

Wastewater Treatment division, potential reclaimed 

water customers, members of the community, and 

other stakeholders were invited, as shown in 

Figure 8-6 [US-WA-King County].

In San Diego, Calif., public demonstration is a major 

phase of the reuse project. In 2004, the city embarked 

on its Water Reuse Program with the goal of 

maximizing water reuse, either through nonpotable

market expansion, potable reuse, or a combination of 

the two. IPR through reservoir augmentation was 

chosen as the preferred strategy and is currently being 

evaluated in the Water Purification Demonstration 

Project (anticipated completion in 2013). 

A successful public outreach and education program is 

attributed for a recent shift in perception about IPR in 

San Diego, cited earlier in this chapter. Aggressive 

outreach to community leaders and the media, public 

tours of the Advanced Water Purification 

demonstration facility, and project presentations to 

interested groups throughout the community helped to 

increase public understanding of the processes 

involved in providing safe reclaimed water [US-CASan Diego]. At the Denver Zoo, where reclaimed water 

is used for animal habitats, animal health and public 

relations experts have ensured and communicated the 

safety and beneficial aspects of water reuse through 

education and outreach efforts [US-CO-Denver Zoo].

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. (Photo courtesy of Jo Sullivan). 
Chapter 8 | Public Outreach, Participation, and Consultation

8-18 2012 Guidelines for Water Reuse

8.6 References

American Water Works Association (AWWA) and Water 

Environment Federation (WEF). 2008. Using Reclaimed 

Water to Augment Potable Water Resources. Second 

Edition. American Water Works Association. Denver, CO.

CH2MHill. 2001. Public Involvement – Making It Work.

AWWA Research Foundation. Denver, CO.

Deeb, R. A. 2010. Communication Principles and Practices, 

Public Perception and Message Effectiveness. Water 

Environment Research Foundation. Alexandria, VA.

Hartley, T. 2003. Water Reuse: Understanding Public 

Perception and Participation. Water Environment Research 

Foundation. Alexandria, VA.

Humphreys, L. 2006. Marketing Nonpotable Recycled Water, 

A Guidebook for Successful Public Outreach & 

Customer Marketing. WateReuse Foundation, accessed 

on February 29, 2012 from 

<http://www.swrcb.ca.gov/water_issues/programs/grants_loa

ns/water_recycling/research/03_005_01.pdf>

International Association of Public Participation. 2007. IAP2. 

Retrieved on May 4, 2012, from IAP2 from

<

. 

http://www.iap2.org/associations/4748/files/IAP2%20Spectr

um_vertical.pdf>

Metcalf & Eddy/AECOM. 2007. Water Reuse Issues, 

Technologies and Applications. McGraw Hill. New York, NY.

.

Peabody, K.; A. Heymann; K. Hurlbutt and S. Merrill 2012. 

“Social Media Demonstrate Their Worth for Utilities and 

Their Stakeholders.” Joint Water Environment Federation 

and American Water Works Association Utility Management 

Conference, February 1, 2012.

Resource Trends, Inc. 2004. Best Practices for Developing 

Indirect Potable Reuse Projects: Phase 1 Report.

WateReuse Foundation. Alexandria, VA. 

Rozin, P., and A. E. Fallon. 1987. “A perspective on disgust.” 

Psychological Review. 94(1),:23 - 41.

San Diego County Water Authority. n.d. Public Opinion 

Research Website. Retrieved February 29, 2012, from 

<http://sdcwa.org/public-opinion-research>. 

Scott, C. A., A. Browning-Aiken, K. J. Ormerod, R. G. 

Varady, C. D. Mogollon, and C. Tessmer. 2011. Guidance 

on Links Between Water Reclamation and Reuse and 

Regional Growth. WRF 06-016-01. WateReuse Research 

Foundation and the U.S. Bureau of Reclamation. 

WateReuse Foundation. Alexandria, VA.

Snyder, S. A. 2008. Pharmaceuticals in the nation's water: 

Assessing potential risks and actions to address the issue. 

Senate Subcommittee on Transportation Safety, 

Infrastructure Security, and Water Quality Hearing. Tuesday, 

April 15, 2008. Washington, D.C.

A Thirsty Planet. n.d.. Your Water. Retrieved July 31, 2012, 

from <http://www.athirstyplanet.com/your_h20>.

U.S. Environmental Protection Agency (EPA). 2004. 

Toolkit for Assessing Potential Allegations of 

Environmental Justice Issues. Retrieved November 

8, 2011, from U.S. Environmental Protection Agency. 

Retrieved August 23, 2012, from 

<http://www.epa.gov/compliance/ej/resources/policy/ejtoolkit.pdf>.

U.S. Bureau of Reclamation (USBR). 2004. Successful 

Public Information and Education Strategies: Southern 

California Water Recycling Projects Initiative. 

Retrieved February 29, 2012, from 

<http://www.usbr.gov/lc/socal/reports/TM_PublicInfoStrategi

es.pdf>

WateReuse Association (WRA). 2009. How To Develop and 

Water Reuse Program. WateReuse Association. Alexandria, 

VA.

. 

WateReuse Association (WRA). 2009. WateReuse 

Association 2008 Property Owner and Homeowner Market 

Perception Study: Final Report. Group 3 Research, 

Pittsburg, PA. 

WateReuse Research Foundation (WRRF). 2010a. The 

Psychology of Water Reclamation and Reuse: Survey 

Findings and Research Road Map. WRF-04-008. 

WateReuse Foundation. Alexandria, VA. 

WateReuse Research Foundation (WRRF). 2010b. 

Research Update: Risk Assessment Study of PPCPS in 

Recycled Water to Support Public Review. WRRF-09-07. 

WateReuse Research Foundation. Alexandria, VA.

WateReuse Research Foundation. (WRRF). 2011. Talking 

About Water: Vocabulary and Images that Support Informed 

Decisions about Water Recycling and Desalination. WRF07-03. WateReuse Research Foundation. Alexandria, VA.

WateReuse Research Foundation (WRRF). 2012. In 

production. The Effect of Prior Knowledge of 'Unplanned' 

Potable Reuse on the Acceptance of 'Planned' Potable 

Reuse. WRF-09-01.WateReuse Research Foundation. 

Alexandria, VA.
2012 Guidelines for Water Reuse 9-1 

CHAPTER 9 

Global Experiences in Water Reuse

9.1 Introduction 

This chapter provides an overview of global 

experiences in water reuse. The primary objectives of 

this chapter are to 1) review a range of drivers, 

barriers, benefits, and incentives for water reuse and 

wastewater use outside of the United States; 2) outline 

the state of, and geographic variation in, water reuse 

and wastewater use; and 3) review paths for 

expanding the scale of safe and sustainable water 

reuse and wastewater use in different contexts. 

Discussion is provided to address these objectives; it

draws on experiences from more than 40 global case 

studies that provide an array of approaches to safe 

and sustainable water reuse. While EPA guidelines 

focus on water reuse, the global abundance of 

wastewater use and the gray lines dividing water reuse 

and wastewater use have led the contributors to 

broaden the scope of this chapter to discuss both 

water reuse and wastewater use outside of the United 

States.

The planning, technical, institutional, and socioeconomic settings in which water reuse is practiced 

varies both among and within countries as a function 

of specific geographic and economic conditions. As a 

result, it is important to define the context of these 

practices, as well as provide case study examples of 

these practices.

9.1.1 Defining the Resources Context

As this chapter examines water reuse across a 

spectrum of resource contexts, it is necessary to draw 

a distinction between resource-endowed and the 

resource-constrained countries. For the purposes of 

this chapter, the term “resource-endowed” countries or 

settings will refer to locations in high-income or 

“developed” countries, and “resource-constrained” 

countries or settings will refer to locations in lowincome or “developing” countries. Locations in middleincome countries or settings may fall into either 

category depending on the context. 

Most resource-endowed countries have established 

human health risk guidelines or standards that involve 

high-technology/high-cost approaches. This enables 

the institution of practices that extend beyond 

protecting human health to providing environmental 

protection and restoration. Many resource-constrained

countries have considered adopting an approach to 

protecting human health based on the WHO’s

recommendations in the WHO Guidelines for the Safe 

Use of Wastewater, Excreta, and Greywater, which 

usually entail a fit-for-purpose, gradational process 

toward reducing health risks (WHO, 2006).

9.1.2 Planned Water Reuse and 

Wastewater Use

For this chapter especially, it is necessary to make a 

distinction between water reuse and wastewater use. 

As defined in Chapter 1, water reuse, for the purposes 

of this document, is the use of treated municipal 

wastewater. Globally, water reuse occurs both in 

resource-constrained settings using low-cost methods 

(as illustrated in case studies [Palestinian TerritoriesAuja] and [Philippines-Market]), as well as in resourceendowed settings, where the more typical high-tech 

applications are seen (as illustrated in case studies: 

[China-MBR], [India-Bangalore], [Japan-Building 

MBR], [South Africa-eMalahleni Mine], and [SpainCosta Brava]). 

Wastewater use is the intentional or unintentional use 

of untreated, partially treated, or mixed wastewater 

that is not practiced under a regulatory framework or 

protocol designed to ensure the safety of the resulting 

water for the intended use. This practice does not 

occur in the United States, as wastewater treatment is 

ubiquitous. Wastewater use occurs mainly for 

agricultural irrigation, and often it is officially prohibited, 

yet unofficially tolerated (informal irrigation sector), 

because many people derive their livelihoods from 

access to untreated or partially treated wastewater. 

Wastewater use may occur, for example, where 

wastewater is knowingly taken from outfall pipes or 

drainage canals because it is easily accessible at no 

cost or can confer benefit over other sources because 

of its high nutrient content when water is used for 

irrigation. Wastewater use can also occur where water 

is taken from natural stream or river channels that 

contain large loads of untreated wastewater mixed 

with freshwater. It should be noted that these 

definitions do not include any judgment about water 
Chapter 9 | Global Experiences in Water Reuse

9-2 2012 Guidelines for Water Reuse

quality and related health risks. In resourceconstrained countries, for example, the quality of 

“treated” wastewater in a planned reuse project can be 

worse than that of untreated, but diluted, wastewater 

collected from streams.

Although wastewater use can have various livelihood 

benefits and support food security, it presents serious 

risks to human health from a range of pathogens that 

may be contained in the wastewater, as described in 

Chapter 6. In addition, where urban or agricultural 

runoff or industrial wastes impact wastewater, 

chemical pollutants may also be present. Exposure to 

untreated wastewater is a likely contributor to the 

burden of diarrheal disease worldwide (WHO, 2004). 

Epidemiological studies suggest that the exposure 

pathways to the use of wastewater in irrigation can 

lead to significant infection risk for the following 

groups:

 Farmers and their families—Several 

epidemiological investigations have found 

excess parasitic, diarrheal, and skin infection 

risks in farmers and their families directly in 

contact with wastewater. There is, in particular, 

a high prevalence of hookworm disease and 

ascariasis infections among those who do not 

use protective gear as the organisms that cause 

those infections (hookworm and roundworm) 

are common in hot climates (WHO, 2006).

 Populations living near wastewater irrigation 

sites, but not directly involved in the 

practice—Populations, particularly children, 

living within or near wastewater irrigation sites 

using sprinklers may be exposed to aerosols 

from untreated wastewater and at risk of 

bacterial and viral infections (Shuval et al. 

1989).

 Consumers of raw produce irrigated with 

wastewater—Excess diarrheal diseases and 

cholera, typhoid, and shigellosis outbreaks have 

been associated with the consumption of 

wastewater-irrigated vegetables eaten 

uncooked (WHO, 2006). In Ghana, for example, 

a burden of disease of 12,000 disabilityadjusted life years (DALY) annually, or 0.017 

DALY per person per year was estimated, which 

represents nearly 10 percent of the WHOreported DALYs occurring in urban Ghana due 

to various types of water- and sanitation-related 

diarrhea (Drechsel and Seidu, 2011). The 

contribution of wastewater use, and in particular 

its impact on consumer food safety, has not 

been quantified so far at larger scale. 

In cases where wastewater treatment prior to use is

not possible, alternative strategies for protecting

human health need to be evaluated and applied (Scott 

et al., 2010; Amoah et al., 2011). In such cases, 

guidelines for the development, contracting, and 

implementation of water reuse can facilitate the 

transition from wastewater use to planned reuse 

systems. 

9.1.3 International Case Studies

A broad range of global water reuse practices are 

discussed in this chapter and in accompanying case 

studies. The geographic location and reuse application 

associated with each case study is displayed in 

Figure 9-1. As a group, the case studies illustrate 

water reuse experiences in a variety of contexts and 

demonstrate the possibilities for expanding the scale 

of safe and sustainable water reuse practices across 

geographies and resource settings. Throughout the 

text, the case studies are referenced by a code name 

in brackets. In the pdf version of this document, 

hyperlinks will direct the reader to the international 

case studies, which are located in Appendix E. A table 

with links to international regulatory websites is also 

provided in Appendix E. 
Chapter 9 | Global Experiences in Water Reuse

2012 Guidelines for Water Reuse 9-3 
Chapter 9 | Global Experiences in Water Reuse

9-4 2012 Guidelines for Water Reuse

Figure 9-1 Legend

Map code Text code Case Study Name

AR-1 Argentina-Mendoza Special Restricted Crop Area in Mendoza, Argentina

AU-1 Australia-Sydney Sewer Mining to Supplement Blackwater Flow in a Commercial High-rise

AU-2 Australia-Graywater Retirement Community Graywater Reuse

AU-3 Australia-Victoria End User Access to Recycled Water via Third Party-Owned Infrastructure

AU-4 Australia-Replacement 

Flows St Marys Advanced Water Recycling Plant, Sydney

BB-1 Barbados-Economic 

Analysis

Economic Analysis of Water Reuse Options in Sustainable Water Resource 

Planning 

BE-1 Belgium-Recharge Water Reclamation for Aquifer Recharge in the Flemish Dunes 

BR-1 Brazil-Car Wash Car Wash Water Reuse - A Brazilian Experience

CA-1 Canada-Nutrient 

Transfer

Water Reuse Concept Analysis for the Diversion of Phosphorus from Lake Simcoe, 

Ontario, Canada

CN-1 China-MBR Water Reuse in China

CO-1 Colombia-Bogotá The Reuse Scenario in Bogotá

CY-1 Cyprus-Irrigation Water Reuse In Cyprus

GH-1 Ghana-Agriculture Implementing Non-conventional Options for Safe Water Reuse in Agriculture in 

Resource Poor Environments

IN-1 India-Delhi Reuse Applications for Treated Wastewater and Fecal Sludge in the Capital City of 

Delhi, India 

IN-2 India-Bangalore V Valley Integrated Water Resource Management: the Bangalore Experience of 

Indirect Potable Reuse

IN-3 India-Nagpur City of Nagpur and MSPGCL Reuse Project

IL-1 Israel/Jordan-Brackish 

Irrigation

Managing Brackish Irrigation Water with High Concentrations of Salts in Arid 

Regions

IL-2 

Israel/Palestinian 

Territories/JordanOlive IrrigationIrrigation of Olives with Recycled Water

IL-3 Israel/Jordan-AWT 

Crop Irrigation Advanced Wastewater Treatment Technology and Reuse for Crop Irrigation

IL-4 Israel/Peru-Vertical 

Wetlands

Treatment of Domestic Wastewater in a Compact Vertical Flow Constructed 

Wetland and its Reuse in Irrigation

JP-1 Japan-Building MBR A Membrane Bioreactor (MBR) Used for Onsite Wastewater Reclamation and 

Reuse in a Private Building in Japan

JO-1 Jordan-Irrigation Water Reuse and Wastewater Management in Jordan

JO-2 Jordan-Cultural 

Factors Cultural and Religious Factors Influence Water Reuse

MX-1 Mexico-Tijuana Water, Wastewater, and Recycled Water Integrated Plan for Tijuana, Mexico

MX-2 Mexico-Mexico City The Planned and Unplanned Reuse of Mexico City’s Wastewater

MX-3 Mexico-Ensenada Maneadero Aquifer, Ensenada, Baja California, Mexico

MX-4 Mexico-San Luis 

Potosi Tenorio Project: A Successful Story of Sustainable Development

PK-1 Pakistan-Faisalabad Faisalabad, Pakistan: Balancing Risks and Benefits

PS-1 Palestinian TerritoriesAuja Friends of the Earth Middle East's Community-led Water Reuse Projects in Auja

PE-1 Peru-Huasta Assessing Water Reuse for Irrigation in Huasta, Peru
Chapter 9 | Global Experiences in Water Reuse

2012 Guidelines for Water Reuse 9-5 

Figure 9-1 Legend

Map code Text code Case Study Name

PH-1 Philippines-Market Wastewater Treatment and Reuse for Public Markets: A Case Study in Sustainable, 

Appropriate Technology in the Philippines

SN-1 Senegal-Dakar Use of Wastewater in Urban Agriculture in Greater Dakar, Senegal: “Adapting the 

2006 WHO Guidelines”

SG-1 Singapore-NEWater The Multi-barrier Safety Approach for Indirect Potable Use and Direct Nonpotable 

Use of NEWATER

ZA-1 South AfricaeMalahleni Mine

Turning Acid Mine Drainage Water into Drinking Water: The eMalahleni Water 

Recycling Project

ZA-2 South Africa-Durban Durban Water Recycling Project

ES-1 Spain-Costa Brava Risk Assessment for Legionella sp. in Reclaimed Water at Tossa de Mar, Costa 

Brava, Spain

TH-1 Thailand-Pig Farm Sam Pran Pig Farm Company: Using Multiple Treatment Technologies to Treat Pig 

Waste in an Urban Setting

TT-1 Trinidad and TobagoBeetham Evaluating Reuse Options for a Reclaimed Water Program in Trinidad, West Indies

UK-1 United KingdomLangford Langford Recycling Scheme 

AE-1 United Arab EmiratesAbu Dhabi Water Reuse as Part of Holistic Water Management in the United Arab Emirates

VN-1 Vietnam-Hanoi Wastewater Reuse in Thanh Tri District, Hanoi Suburb, Vietnam
Chapter 9 | Global Experiences in Water Reuse

9-6 2012 Guidelines for Water Reuse

9.2 Overview of Global Water Reuse 

This section provides an overview of the global status 

of water reuse, and the case studies illustrate the 

diverse range of water reuse applications worldwide. 

9.2.1 Types of Water Reuse

Water is reused worldwide for agriculture, aquaculture, 

industry, drinking water, nonpotable household uses, 

landscape irrigation, recreation, and groundwater 

recharge. Note that these uses are described in 

greater detail in Chapter 3, as they are likewise 

practiced in the United States. Figure 9-2 shows types 

of reuse after advanced (tertiary) treatment, which 

describes only a portion of the actual reuse practiced 

worldwide. 

9.2.1.1 Agricultural Applications 

Consistent with the high proportion of fresh water use 

in the agricultural sector, most reclaimed water used 

globally serves crop production. Many of the case 

studies describe applications of using reclaimed water 

or wastewater for irrigation or other agricultural 

applications, such as projects highlighted in the 

following case studies from around the world. In 

Victoria, reclaimed water is used to irrigate vineyards, 

tomatoes, potatoes, and other crops in addition to 

traditional landscape irrigation [Australia-Victoria]. 

Citrus and olive trees and fodder crops use 

approximately 90 percent of the available reclaimed 

water on Cyprus [Cyprus-Irrigation]. Constructed 

vertical wetlands are being tested and applied for 

irrigation of fruit trees and gardens in decentralized 

treatment systems [Israel/Peru-Vertical Wetlands]. In 

Mexico City, nearly 46 mgd or reclaimed water is used 

for irrigation of green areas, recharge of recreational 

lakes and agriculture [Mexico-Mexico City]. Fodder 

crop irrigation predominates in Jordan with some 

application for irrigation of date palms and olives 

[Jordan-Irrigation].

9.2.1.2 Urban and Industrial Applications

Technology-driven approaches that promote advanced 

reuse include the NEWater project in Singapore 

[Singapore-NEWater], sensitive manufacturing 

operations [South Africa-Durban], high-rise office 

treatment and recycling in Sydney [Australia-Sydney], 

retirement center toilet flushing and landscape 

irrigation [Australia-Graywater], and in high-rise 

buildings in Japan [Japan-Building MBR], other 

industrial reuse including vehicle washing ([Brazil-Car 

Wash] and [Mexico-Mexico City]), and cooling for 

manufacturing operations or energy production as 

demonstrated in several case studies throughout the 

world ([Jordan-Irrigation], [Trinidad and TobagoBeetham], [Mexico-Mexico City], [India-Delhi], and 

[India-Nagpur]). In the Philippines, reclaimed water 

from a satellite plant serving the produce market is 

used for toilet flushing, street washing and plant 

watering [Philippines-Market]. Reclaimed water is used 

in Spain for traditional nonpotable irrigation, street 

Other 1.5%

Landscape irrigation 

20.01%

Groundwater 

recharge 2.1%

Recreational 6.39%

Non-potable urban

uses 8.25%

Indirect potable 

reuse 2.3%

Agricultural irrigation 

32.01%

Industrial 19.32%

Environmental 

enhancements 8.04%

Water Reuse 

by Application

Figure 9-2

Global water reuse after advanced (tertiary) treatment: market share by application (Figure 

taken from Municipal Water Reuse Markets 2010 from the publishers of Global Water 

Intelligence) 
Chapter 9 | Global Experiences in Water Reuse

2012 Guidelines for Water Reuse 9-7 

washing, fire hydrants, and washdown at the 

community dog shelter [Spain-Costa Brava]. A wide 

variety of industries, including commercial laundries, 

vehicle-washing establishments, pulp and paper 

industries, steel production, textile manufacturing, 

electroplating and semiconductor industries, boilerfeed water, water for gas stack scrubbing, meat 

processing industries, brewery and beverage

industries, and power plants, have the capability to use 

reclaimed water in their operations (Jimenez and

Asano, 2008). In the food and beverage industry, 

reclaimed water is used for cooling and site amenities. 

Internal process water may also be recirculated or 

reused with appropriate treatment. Urban amenities, 

such as stream restoration and other features, may 

involve reclaimed water, thus representing elements of 

“cities of the future” visions for sustainable cities 

(Jimenez and Asano, 2008). In the case study from 

Barbados, the economic, environmental, and social 

trade-offs of various reuse schemes were considered 

[Barbados-Economic Analysis].

9.2.1.3 Aquifer Recharge 

Groundwater or aquifer recharge, both planned and de 

facto, is likewise practiced globally (Jimenez and 

Asano, 2008). Documented cases of aquifer recharge 

are reported in Israel, South Africa, Germany, Belgium 

[Belgium-Recharge], Australia, Namibia, India, Italy, 

Mexico, China, Barbados [Barbados-Economic 

Analysis], and Cyprus [Cyprus-Irrigation]. Indirect 

potable recharge following advanced treatment has 

been studied in Tijuana but not yet implemented 

[Mexico-Tijuana]. Planned recharge with reclaimed 

water provides subsurface storage and can enable 

additional treatment, as discussed in Chapters 3 and 

6. In addition to storage for nonpotable reuse (e.g., for 

agricultural or landscape irrigation, industrial use, etc.) 

or IPR, replenishment of aquifers experiencing higher 

rates of withdrawal than natural recharge can prevent 

saltwater intrusion in groundwater supply in coastal 

areas and supplement groundwater base flows to 

promote ecosystem health. On a global scale, 

wastewater-impacted aquifer recharge is widespread. 

Often highly polluted and only partially treated (if at 

all), wastewater drains to rivers or drainage canals 

connected to underlying unconfined aquifers that may 

be used for drinking water.

Regardless of the type of reuse application, water 

quality issues are an important dimension. Ideally, the 

wastewater source and type of treatment should be 

matched to the eventual reuse application, also known 

as “Fit for Purpose,” as described in Chapter 1. 

Reclaimed water suppliers may need to be certified 

and provide proof of compliance with water quality 

specifications before they are allowed to supply water 

to consumers, and systems should be in place to store 

and retreat water that fails to meet standards and to 

avoid cross-connection between the distribution 

systems for reclaimed water and potable drinking 

water. The planning and management of water reuse 

is described in Chapter 2.

9.2.2 Magnitude of Global Water Reuse

The total volume of domestic wastewater generated in 

the world every day is estimated to be between 180 

and 250 billion gallons (680 and 960 million m3), as 

shown in Table 9-1 (GWI, 2010; FAO, 2010). The 

current global capacity to treat wastewater to 

advanced levels (like tertiary treatment) is 

approximately 8 billion gallons per day (32 million 

m3/day), or only 4 percent of the total volume of 

wastewater that is generated (GWI, 2010). The volume 

of wastewater treated beyond secondary treatment for 

reuse has grown by an average of 500 mgd (2 million 

m3/day) each year since 2000, allowing a greater 

proportion of water to be safely reused (GWI, 2010). 

Wastewater production is likely to increase with 

population growth; with expanded sewerage networks

there is great potential for expanding the magnitude of 

global water reuse, especially for high-end usages. 

Table 9-1 Global domestic wastewater generated and 

treated (in billion gallons per day and million cubic 

meters per day)

Volume (billion 

gallons per 

day)

Volume 

(million 

m3/day)

Total volume of domestic 

wastewater generated as of 

2009

180-250 680-960

Current global capacity to 

treat wastewater to 

advanced levels as of 2009

8 32

Total volume of domestic 

wastewater that is not 

treated to advanced levels 

as of 2009

172-242 648-928

Growth in global capacity to 

treat wastewater to 

advanced levels (per year 

since 2000) 

0.5 2 

Sources: GWI, 2010; FAO, 2010

There is limited reliable data documenting quantities of 

water reuse and wastewater use in the agricultural 
Chapter 9 | Global Experiences in Water Reuse

9-8 2012 Guidelines for Water Reuse

sector. The limited evidence that does exist, which is 

not geographically comprehensive, suggests that the 

area of land irrigated with untreated wastewater is 

more than 10 times as great as the area irrigated with 

reclaimed water (Scott et al., 2010). Rough estimates 

suggest that about 20 million ha of agricultural land is 

irrigated with mostly untreated wastewater globally 

(Figure 9-3), and crops produced from such irrigation 

comprise 10 percent of global agricultural production 

from irrigation (Scheierling et al., 2010; Drechsel et al., 

2010). As such, the proportion of wastewater used in 

agriculture may be far greater than that shown in 

Figure 9-3, which only summarizes documented 

cases. 

Growth in the global water reuse sector is expected to 

migrate from being dominated by agricultural reuse 

toward higher-value applications, mostly in municipal 

applications, such as potable, industrial, and 

landscape irrigation reuse. China, the United States, 

Spain, Mexico, India, Australia, Israel, Kuwait, Japan, 

and Singapore lead the world in total installed 

advanced water reuse capacity to date (GWI, 2010). 

GWI projects that global capital expenditure in 

advanced water reuse is expected to grow 19.5 

percent annually between 2009 and 2016 (GWI, 

2010). The countries that are projected to add the 

greatest additional advanced water reuse are shown in 

Table 9-2. Many of these countries have recently 

completed major investments in desalination and are 

now turning to growth in the water reuse sector to 

meet needs, particularly in growing urban populations.

Table 9-2 Projected reuse capacity in selected 

countries (data taken from Municipal Water Reuse 

Markets 2010 from the publishers of Global Water 

Intelligence)

Country

Additional advanced reuse 

capacity (2009-2016)

Billion gallons 

per day

Million 

m3/day

USA 2.8 10.7

China 1.6 5.9

Saudi Arabia 0.9 3.5

Australia 0.7 2.5

Spain 0.6 2.1

Mexico 0.6 2.1

United Arab Emirates 0.5 1.9

Oman 0.4 1.6

India 0.3 1.2

Algeria 0.3 1.1

Source: GWI, 2010

DPR and planned IPR still account for a minor 

proportion of water reuse worldwide (2.30 percent), but

the proportion is growing. Of all advanced reuse, 

approximately 2.3 percent is potable reuse (GWI, 

2010). Growth in potable reuse applications is driven 

by pressures on water supply, along with increased 

public acceptance because of successful records of 

performance demonstrated by notable installations in 

the United States, Namibia, South Africa, and 

Singapore (GWI, 2010, NRC, 2012). A table 

summarizing a sampling of IPR installations (and 

potable in Namibia) is provided in Chapter 3 to 

illustrate that this practice occurs worldwide, at both 

very small and very large scales. Singapore has made 

water reuse a national priority, as described in a case 

study [Singapore-NEWater]. Decision-makers in 

Bangalore, India, are developing plans to include IPR

as part of an overall approach to narrow gaps between 

water supply and the demands of a growing population 

[India-Bangalore]. And in South Africa, a novel 

partnership between a mining company and a 

township is turning acid mine drainage into drinking 

water [South Africa-eMalahleni Mine]. Note that 

countless other planned IPR applications exist where 

reclaimed water is deliberately recharged to a 

groundwater aquifer using rapid infiltration basins or 

injection wells or to a drinking water reservoir. A 

representative example of this is from Wulpen, 

Belgium, where reclaimed water is returned to the 

aquifer before being reused as a potable water source 

[Belgium-Recharge]. An example of de facto IPR

comes from Langford, UK, where reclaimed water is 

returned upstream to a river that is the potable water 

source [United Kingdom-Langford].

9.3 Opportunities and Challenges for 

Expanding the Scale of Global Water 

Reuse

While the opportunities for expanding reuse are quite 

significant, there are some challenges related to the 

country-specific drivers, the regional variation of 

climate, social acceptance, and financial resources. 

While some of these factors are barriers to reuse, the 

benefits of expanding the water reuse will likely 

outweigh the challenges, ultimately paving the way for 

reuse to become an ever-growing part of the global 

water resource/water supply solution. 
Chapter 9 | Global Experiences in Water Reuse

2012 Guidelines for Water Reuse 9-9 

9.3.1 Global Drivers 

Global water reuse is primarily driven by two main 

factors. First, reuse is a response to rising demand for 

water and limitations on freshwater availability. 

Second, water reuse is driven by a desire to capture 

and harness the economic benefits of wastewater. 

Wastewater use, on the other hand, is usually driven 

by the lack of wastewater collection and/or treatment 

facilities, resulting in untreated wastewater being 

discharged into the environment where, especially in 

urban and peri-urban areas of resource-constrained 

settings, safer water sources are difficult to find 

(Jimenez et al., 2010; Scott et al., 2010).

The first group of drivers for water reuse typically 

catalyzes reuse in areas of physical water scarcity, 

such as the Middle East and North Africa region, 

Australia, Singapore, and parts of southern Africa. 

Thus, poor water resources management and climate 

change may exacerbate conditions of scarcity in some 

countries and create conditions of scarcity in others. In 

resource-endowed settings, a desire to protect 

freshwater resources has fostered the creation of 

environmental regulations that limit the quantity of 

water available for human use and uphold standards 

for the quality of effluent resulting from such use. 

Application of these regulations has, in turn, promoted 

greater reuse of existing water rather than 

development of new water sources. 

Economic considerations are also beginning to drive 

water reuse in high-resource contexts, as the 

possibility of marketing reclaimed water as a 

commodity holds the promise of partial return on 

investment for wastewater treatment (Jimenez et al., 

2010). Trends in resource-endowed settings are 

moving toward the use of treated water at increasingly 

higher water quality standards for higher-value uses, 

such as industrial and municipal uses. The prospect of 

water scarcity begins to discourage lower-value uses, 

such as agricultural irrigation and aquifer recharge and 

free or heavily-subsidized use of reclaimed water 

(GWI, 2010). Economic benefits associated with 

formal water reuse projects are more likely to be 

achieved over longer timeframes compared to shorterterm gains from transporting water from distant 

sources, groundwater mining, and reservoir 

construction (GWI, 2010). 

Figure 9-3 

Countries with greatest irrigated areas using treated and untreated wastewater 

(Adapted from Scott et al., 2010). 
Chapter 9 | Global Experiences in Water Reuse

9-10 2012 Guidelines for Water Reuse

Wastewater use is often driven by resource constraints 

and high rainfall variability; wastewater may constitute 

a large proportion or even all of the flow in water 

bodies during the dry season. Scarcity of safe water 

due to the pollution of water resources with 

wastewater is common in low-resource contexts 

across any climate, leading to wastewater use. Indeed, 

in resource-constrained settings, untreated wastewater 

can serve as an economic resource for poor urban and 

peri-urban farmers. In many instances, these farmers 

have no viable alternative to the use of wastewater for 

their livelihood needs, yet use of such wastewater or 

polluted stream water often poses a significant threat 

to the public health of producers and consumers of 

farm products if not appropriately addressed. An 

interesting case of wastewater use comes from 

Pakistan, where local farmers, following extensive 

legal cases and now with permission from the local 

water and sanitation authority, have installed a 

permanent conveyance of untreated wastewater to 

their irrigation networks. While there is an existing 

WWTP (a waste stabilization pond), farmers have 

been opposed to using treated effluent, as it was much 

lower in nutrients and much higher in salinity (as a 

result of massive evaporation from the waste 

stabilization pond) than untreated wastewater 

[Pakistan-Faisalabad]. 

9.3.2 Regional Variation in Water Reuse

Factors affecting the regional dynamics of water reuse 

include economic development priorities, water 

management options, environmental and climatic 

factors, social acceptance, and availability of financial 

resources. Water reuse in the Middle East and North 

Africa region is typically driven by water scarcity. 

Some high-income countries in the region use 

desalination to meet drinking water supply needs and 

use reclaimed water for agricultural and landscape 

irrigation using standards based on California Title 22. 

Middle- and low-income countries in the region use 

partially-treated or untreated wastewater primarily for 

specific restricted types of agricultural irrigation and 

utilize the previous WHO (1989) guidelines to inform 

approaches to improve human health and safety of 

water reuse practices (Jimenez and Asano, 2008).

Analysis of reuse patterns in sub-Saharan Africa is 

hampered by a lack of reliable data. Limited existing 

evidence suggests that water reuse is driven by water 

scarcity (Jimenez et al., 2010). In this region, 

wastewater serves as a reliable water supply for 

multiple uses and as a source of high nutrient content 

for agricultural irrigation. Although much of the 

wastewater use in this region is informal and occurs in 

the agricultural sector, one of the most high profile and 

pioneering examples of potable water reuse is a 40-

year ongoing project in Namibia involving direct human 

consumption of highly-purified reclaimed water.

In northern Europe, water reuse is practiced primarily 

for environmental and industrial applications, whereas 

in southern Europe, environmental and agricultural 

applications dominate. Practices generally follow the 

WHO (1989) guidelines or regulations that closely 

emulate California Title 22 standards.

Across Central and South America, water reuse is 

driven by water scarcity and by a desire to recycle 

wastewater nutrients in areas of poor soil quality. But 

lack of sanitation is also leading to some of the largest 

areas of wastewater use, like in Mexico and Chile. 

Water scarcity is the main driver for planned reuse in 

the drier areas of the Caribbean islands, Mexico, and 

Peru. Agricultural irrigation is the primary application. 

Wastewater use dominates, although there are many 

documented cases of planned reuse projects. WHO 

(1989) guidelines are used to improve the safety of 

reuse practices, but implementation is not universal.

The situation in Asia varies among its subregions. 

While China and India show significant progress in 

high-quality reuse (GWI, 2010), both countries are still 

among the global leaders of unplanned use of 

wastewater (Figure 8-3), often via contaminated 

streams. Poor sanitation is also driving wastewater 

use across Central Asia and, to an even greater 

degree, Southeast Asia, where, in addition to 

agriculture, wastewater-fed aquaculture is also 

common. 

Reuse in Australia is driven by both water scarcity and 

high environmental standards. Key applications 

include industrial mining, agricultural irrigation, and 

recreation. National coordinated water policies have 

incentivized expansion of water reuse practices, and 

regulations recognize a combination of natural 

treatment and advanced technology approaches.
Chapter 9 | Global Experiences in Water Reuse

2012 Guidelines for Water Reuse 9-11

9.3.3 Global Barriers to Expanding 

Planned Reuse

From a technical standpoint, water reuse is a logical 

part of the overall water supply and water resources 

management solution. However, there are often 

projects that are technically feasible but do not get 

implemented. In these cases, the barriers to 

implementing reuse are often institutional, economic, 

organizational, or related to public perception/

education. Thus, a discussion of these non-technical 

barriers to expanding planned reuse is provided in this 

section. 

9.3.3.1 Institutional Barriers

A basic driver of wastewater use—and barrier to 

wastewater treatment and planned reuse—in much of 

the world is the dearth of effective collection and 

treatment systems for fecal matter and sewage 

(Table 9-3). In resource-endowed urban areas, 

comprehensive sewer system coverage serves as a 

conduit for wastewater to be channeled to treatment 

plants in order to be safely released or reused. In 

resource-constrained settings, however, such 

infrastructure often either does not exist or does not 

terminate in functional treatment plants. While 

developing an extensive sewerage network is often a 

recommended step toward improving water reuse, it is 

important to recognize that improvements in on-site 

sanitation systems and related collection services can 

also significantly reduce the environmental burden and 

health risks associated with wastewater management. 

It is worth noting that China has made a strong 

emphasis on installing urban wastewater treatment 

over the past decade. As of 2010, 75 percent of 

Chinese cities are now connected to wastewater 

treatment, according to official governmental estimates 

(Xinhua, 2011).

While lack of appropriate infrastructure poses a 

constraint on water collection, treatment, and safe 

reuse in some areas, there are at least two broader 

barriers to planned water reuse. They are 1) limited 

institutional capacity to formulate and institutionalize 

enabling legislation and to subsequently conduct 

adequate enforcement and monitoring of water reuse 

activities, and 2) lack of expertise in health and 

environmental risk assessment and mitigation. One 

limiting factor is a lack of political will to formalize an 

existing use of untreated or partially treated 

wastewater due to the institutional and enforcement 

hurdles that must be put in place to support planned 

reuse. Governments may feel they lack the capacity 

and budget to adequately implement these necessary 

reforms and thus risk causing farmers to lose access 

to existing sources of irrigation water. An underlying 

basis for these barriers, in turn, has been a funding 

bias towards conventional infrastructure investments, 

which may not always be fit-for-purpose (Nhapi and 

Gijzen, 2004; Murray and Drechsel, 2011). A critical 

issue, highlighted in subsequent sections, is adapting 

regulations and institutional capacities to local contexts 

to achieve the achievable rather than adopting overambitious policies that spur few sustainable, on-theground improvements. Australia has provided 

technical guidance to providers and users in designing 

agreements that address the legal and technical 

aspects of reuse and, therefore, allow providers to 

better control their costs (Wintgens and Hochstrat, 

2006). 

Table 9-3 Percent of urban populations connected to 

piped sewer systems in 2003-2006 (regional averages)

Region

Number of 

countries with 

available data

Connected 

urban 

population 

(%)

United States and 

Canada 2 94

European Union* 18 90

Australia* 1 87

Central Asia 5 83

Middle East and North 

Africa 7 83

Namibia, South Africa, 

Zambia, Zimbabwe 4 68

Latin America and the 

Caribbean 21 64

China 1 56

South Asia 6 31

Sub-Saharan Africa ** 24 9

South-East Asia 5 3 

Source (all countries except United States): Modified after 

Evans et al. 2012; based on Joint Monitoring Programme, 

2012; United Nations Department of Economic and Social 

Affairs, 2011; United Nations Statistics Division, 2011; and 

Eurostat, 2006. US data: GWI, 2010 (population served in 

2004) and JMP, 2012 (population in 2004).

* Rural and urban population 

** Excluding Namibia, South Africa, Zambia, Zimbabwe 

Note: Sewer connection does not automatically imply 

wastewater treatment. 
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9-12 2012 Guidelines for Water Reuse

9.3.3.2 Public Perception/ Educational 

Barriers

Additional barriers include public perceptions that may 

drive fear of the dangers of consuming food irrigated 

with reclaimed water, spurring a preference for use of 

freshwater. Concerns about the failure of conventional 

treatment technologies to remove TrOCs, such as 

pharmaceuticals and endocrine disruptors, are also an 

impediment to reuse for drinking water supply 

purposes (GWI, 2010). However, successful potable 

reuse projects and increased familiarity with advanced 

treatment technologies, such as UF, RO, and UV 

disinfection, signal a possibility that public discomfort 

with potable reuse may be declining (GWI, 2010). As 

described in Chapter 8, public outreach programs to 

build awareness and involve community members in 

planning can change resistance to reuse. Singapore 

has carried out an impressive public awareness 

program to build a national commitment to water reuse 

[Singapore-NEWater]. In the city of San Diego, Calif., 

intense public opposition to water reuse changed over 

a period of many years, largely because of public 

outreach and stakeholder involvement, in addition to 

the economic driver of local water scarcity [US-CASan Diego].

In resource-constrained settings, public attention to 

risks of using untreated wastewater has not reached 

the level of attention as in resource-endowed settings. 

However, public attitudes are subject to change, 

particularly in response to real or perceived failures or 

contamination events and associated media attention 

(Wintgens and Hochstrat, 2006). Establishing a 

regulatory framework for water reuse practices and 

health- or environmental-based standards or 

guidelines, ideally based on internationally-recognized 

guidelines, should be a first step (Jimenez and Asano, 

2008). To promote risk awareness and behavior 

change, educational campaigns and social marketing 

techniques will be required where obvious benefits are 

not perceived (Karg and Drechsel, 2011) 

As discussed in Chapter 8, proper use of language 

that does not stigmatize reclaimed water is also quite 

important when water professionals communicate 

water reuse ideas to the public. Words such as 

“wastewater reuse,” “reuse water,” etc., are 

stigmatizing and negative to the public while “water 

recycling,” “new water,” “purified water”—and to a 

lesser extent “reclaimed water”—are more appealing 

and likely to promote public acceptance (Macpherson, 

2012). To clarify the appropriateness of reclaimed 

water to the faithful, certain Muslim scholars have 

issued Fatwas declaring that reclaimed water is clean 

enough for ablution and other purposes, as long as 

technical experts attest to its purity and safety for such 

uses. Examples of these Fatwas can be viewed in 

original Arabic and in English translation and are 

described in a case study from Jordan [Jordan-Cultural 

Factors] (Senior Scholars Board in the City of Taif, 

1978; Abu Dhabi Islamic Court, 1999).

9.3.3.3 Economic Barriers

The long-term economic viability of reuse projects also 

represents an important barrier to water reuse. 

Reclaimed water is often priced just below the 

consumer cost of drinking water to make it more 

attractive to potential users, but this may also affect 

the ability to recover costs (Jimenez and Asano, 

2008). Distortion in the market for drinking water 

supply complicates the pricing of reclaimed water, as 

does the lack of accounting for externalities, including 

water scarcity and social, financial, and environmental 

burdens of effluent disposal in the environment 

(Wintgens and Hochstrat, 2006; Sheikh et al., 1998). 

Although there is a movement towards increased or 

even full operations and maintenance cost recovery in 

the large market of agriculture water reuse (Morocco, 

Tunisia, Jordan), this is still the exception among many 

state-run service providers. There may, however, be 

opportunities to set different tariff levels for different 

classes or types of users, thus subsidizing the 

resource for the poor while recovering costs from 

groups that are able to pay. Finally, financing of upfront costs remains an important barrier to introducing 

new reuse programs and often requires government 

intervention in the form of grants or subsidies 

combined with eventual revenues. 

9.3.3.4 Organizational Barriers

Fragmentation of responsibilities for and authority over

different parts of the water cycle is another impediment 

that must be overcome before water reuse projects 

can go forward. In many regions the authority over the 

water supply sector resides in an entirely different 

organization than that over wastewater management. 

This separation of powers leads to long periods of 

inaction, stalemate, disagreement, negotiation, and 

complex interagency agreements that make the 

resulting water reuse project far more costly and 

complex than need be. Regions where the same 

authority manages water, wastewater, stormwater, and 
Chapter 9 | Global Experiences in Water Reuse

2012 Guidelines for Water Reuse 9-13

the watershed are far more nimble, implementing their 

water reuse projects quickly, efficiently, and at much 

lower cost (Sheikh, 2004).

9.3.4 Benefits of Expanding the Scale of 

Water Reuse 

Similar to the factors driving current levels of water 

reuse, a range of incentives for increasing, especially, 

planned water reuse in the coming years appear to 

exist. Indeed, there are at least several economic, 

environmental, and social benefits that can be 

achieved through expanding safe and sustainable 

reuse of water. 

First, there is an opportunity to increase water 

availability and reliability without tapping new water 

sources, which either may not exist or may carry 

adverse consequences. For example, as there has 

been increased opposition on environmental grounds 

to dam-building projects, new desalination plants, and 

groundwater mining as a means of securing new water 

supplies, water reuse has emerged as a viable and 

more environmentally-sound alternative (GWI, 2010). 

Water reuse also avoids environmental pollution 

caused by releasing wastewater, treated or not, to 

receiving streams. Reclaimed water is available 

continuously, even during drought periods, and is 

produced where people live. Additionally, the use of 

reclaimed water may augment natural flows in surface 

waters (with cascading positive effects on ecosystem 

health and biodiversity) and may contribute to rising 

groundwater tables where reclaimed water is used for 

crop or landscaping irrigation, as has been 

documented in parts of Mexico (IWMI and Global 

Water Partnership, 2006). 

Second, reuse provides opportunities to recover 

valuable resources, including water, energy, and 

nutrients. Third, expanding safe and sustainable water 

reuse helps reduce the human health costs associated 

with unplanned wastewater use. Finally, increasing 

water availability through reuse may help to reduce 

conflicts over water due to scarcity or resource 

limitations. 

Some benefits are specific to or more commonly occur 

in resource-endowed or resource-constrained settings. 

For example, recreational (contact or non-contact) or 

aesthetic benefits may be experienced in resourceendowed settings when water is reused in urban water 

features and stream restoration projects. Other 

benefits that are more likely to occur in resourceendowed contexts include partial recovery of treatment 

costs; savings on production costs in industrial reuse 

scenarios; and cost savings when treatment is 

matched to eventual reuse applications. In resourceconstrained settings, likely benefits include increased 

nutrition, food security, and income (Keraita et al., 

2008) for farmers, as well as other groups along the 

urban/peri-urban agricultural value chain, including 

women who are often traders of urban agricultural

products in Sub-Saharan Africa (IWMI and GWP, 

2006).

9.4 Improving Safe and Sustainable 

Water Reuse for Optimal Benefits 

There are different options for optimizing benefits of 

safe and sustainable water reuse. In areas where 

wastewater use is currently being practiced, there are 

ways to reduce the risks associated with it without 

treating wastewater prior to use. It may also be 

possible to begin transitioning to wastewater treatment 

and water reuse when certain factors are present, as 

described in Section 9.4. Finally, in areas where water 

reuse is currently occurring, there are ways to optimize 

benefits of reuse by transitioning to higher-value uses 

and imposing stricter regulations for environmental 

conservation. 

Importantly, the sheer scale of the opportunity (or 

challenge) for increasing safe and sustainable water 

reuse may call for use of any combination or all of 

these approaches. There is indeed tremendous 

potential to increase the scale of safe and sustainable 

water reuse, for at least two reasons. First, as 

highlighted above, only a small proportion of 

wastewater that is currently generated is used in a 

planned context for high-value applications. Second, 

given trends in population growth and urbanization, the 

quantity of wastewater generated is likely to increase 

substantially in the future. 

9.4.1 Reducing Risks of Unplanned 

Reuse: The WHO Approach

Improving safe and sustainable water reuse in areas of 

currently unplanned practice has been greatly 

influenced by the WHO guidelines (1989, 2006). In 

2006 the WHO released a four-volume report titled 

Guidelines for the Safe Use of Wastewater, Excreta 

and Greywater. The first volume focuses on policy and 

regulatory aspects of wastewater, excreta, and 

graywater use; the second volume focuses on use of 
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9-14 2012 Guidelines for Water Reuse

wastewater in agriculture; the third volume focuses on 

wastewater and graywater use in aquaculture; the 

fourth volume focuses on excreta and graywater use in 

agriculture. The discussion in the WHO guidelines is 

limited to wastewater, excreta, and graywater from 

domestic sources that are applied in agriculture and 

aquaculture.

Rather than relying on water quality thresholds as in 

past editions (WHO, 1989), the most current WHO 

guidelines (2006) adopt a comprehensive risk 

assessment and management framework. This risk 

assessment framework identifies and distinguishes 

among vulnerable communities (agricultural workers, 

members of communities where wastewater-fed 

agriculture is practiced, and consumers) and considers 

trade-offs between potential risks and nutritional 

benefits in a wider development context. As such, the 

WHO approach recognizes that conventional 

wastewater treatment may not always be feasible, 

particularly in resource-constrained settings, and offers 

alternative measures that can reduce the disease 

burden of wastewater use. The specific approach 

utilized by the WHO (2006) guidelines is to 1) define a 

tolerable maximum additional burden of disease, 2) 

derive tolerable risks of disease and infection, 3) 

determine the required pathogen reduction(s) to 

ensure that the tolerable disease and infection risks 

are not exceeded, 4) determine how the required 

pathogen reductions can be achieved, and 5) put in 

place a system for verification monitoring.

Table 9-4 presents an overview of selected treatment 

and non- or post-treatment health protection measures 

in agricultural water reuse and their potential to reduce 

pathogen loads (WHO, 2006; Amoah et al., 2011). 

While each of the risk mitigation measures can be 

employed in isolation, comprehensive risk reduction is 

best achieved when measures are used in 

combination—the multi-barrier approach. To protect 

farmers themselves, awareness campaigns on the 

invisible risk of pathogens should accompany the 

promotion of protective clothing (boots, gloves, etc.), 

hygiene, and where possible, a shift to irrigation 

methods that minimize human exposure, like drip 

irrigation. Compared to conventional wastewater 

treatment, on- and off-farm risk mitigation measures 

are usually cheaper and more cost-effective, indicating 

suitability for resource-constrained contexts. For 

example, estimates from Ghana show that some of 

these measures can avert up to 90 percent of the 

estimated disease burden related to wastewater 

irrigation at a cost-effectiveness below $100 per 

averted DALY [Ghana-Agricultural] (Drechsel and 

Seidu, 2011). The case study from Senegal illustrates 

how unsafe wastewater use can be tied up in complex 

political factors. In Dakar, Senegal, urban farmers 

divert wastewater from sewage pipes to irrigate their 

small plots. As these plots are often seized for 

housing, farmers choose to grow short-rotation crops 

such as lettuce. If farmers were guaranteed a more 

formalized land tenure status, they might be willing to 

make longer-term investments in on-site water 

treatment approaches or switch crop choices to those 

that grow slower (with similar overall profit), but are not 

eaten raw [Senegal-Dakar]. The health protection 

measures listed in Table 9-4 could be implemented to 

improve the unsafe use of diluted wastewater for 

vegetable production pictured in Figure 9-4. 

The most effective health protection recommendation 

is the production of crops not eaten raw. However, this 

option requires appropriate monitoring capacity and 

viable crop alternatives for farmers. Other options 

include on-farm treatment and application techniques, 

as well as the support of natural die-off as described in 

two Africa case studies, [Ghana-Agricultural] and 

[Senegal-Dakar], and natural attenuation in non-edible 

aquatic plants lining irrigation canals [Vietnam-Hanoi]

(Amoah, et al., 2011). There is reported success of 

blending of wastewater with higher-quality water to 

make it more suitable for production ([Vietnam-Hanoi], 

[Senegal-Dakar], [India-Delhi], [Jordan-Irrigation], and 

[Israel/Palestinian Territories/Jordan-Olive Irrigation]. 

In addition to the risks from pathogen contamination, 

wastewater may have chemical contaminants from 

industrial discharges or stormwater runoff. The WHO 

(2006) guidelines provide maximum tolerable soil 

concentrations of various toxic chemicals based on 

human exposure through the food chain. For irrigation 

water quality, WHO refers to the FAO guidelines, 

which focus on plant growth requirements and 

limitations (Ayers and Westcot, 1985; Pescod, 1992). 

The guidelines do not specifically address how to 

reduce chemical contaminants from wastewater for 

use in irrigation. Resource-constrained countries may 

have historically been less prone to heavy metal 

contamination that is usually localized and associated 

with industrial activities, but where industries are 

emerging, industrial source control measures are 

required to avoid potential contamination in food crops. 
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2012 Guidelines for Water Reuse 9-15

Likewise, where required, stormwater should be 

diverted and treated to remove pollutants. Alternative 

options for low-income countries to reduce the 

potential risk of chemical contamination, like through 

phytoextraction, crop selection, and soil treatment are 

limited (Simmons et al., 2010).

Table 9-4 Selected health-protection measures and associated pathogen reductions for wastewater reuse in 

agriculture

Control measure

Pathogen 

reduction (log 

units) Notes

A. Wastewater treatment 1−6 Pathogen reduction depends on type and degree of treatment 

technology selected.

B. On-farm options

Alternative land and water source 6-7 

In Ghana, authorities supported urban farmers using 

wastewater by drilling wells. In Benin, farmers were offered 

alternative land with access to safer water sources.

Crop restriction (i.e., no food crops 

eaten uncooked) 6−7

Depends on (a) effectiveness of local enforcement of crop 

restriction, and (b) comparative profit margin of the alternative 

crop(s). 

On-farm treatment:

(a) Three-tank system 1−2 One pond is being filled by the farmer, one is settling and the 

settled water from the third is being used for irrigation

(b) Simple sedimentation 0.5−1 Sedimentation for ~18 hours.

(c) Simple filtration 1−3 Value depends on filtration system used

Pathogen die-off (fecal sludge) in line with WHO 

2006

Raw fecal sludge used in cereal farming in Ghana and India 

should be dewatered on-farm for ≥ 60 days or ≥ 90 days 

depending on the application method (spread vs. pit) to 

minimize occupational health risks. 

Method of wastewater application:

(a) Furrow irrigation 1−2 Crop density and yield may be reduced.

(b) Low-cost drip irrigation 2−4 2-log unit reduction for low-growing crops, and

4-log unit reduction for high-growing crops.

(c) Reduction of splashing 1−2

Farmers trained to reduce splashing when watering cans used 

(splashing adds contaminated soil particles on to crop surfaces 

which can be minimized).

Pathogen die-off (wastewater) 0.5−2

per day

Die-off support through irrigation cessation before harvest 

(value depends on climate, crop type, etc.). 

C. Post-harvest options at local markets

Overnight storage in baskets 0.5−1

Selling produce after overnight storage in baskets (rather than 

overnight storage in sacks or selling fresh produce without 

overnight storage).

Produce preparation prior to sale 1−2 (a) Washing salad crops, vegetables and fruit with clean water. 

2−3 (b) Washing salad crops, vegetables and fruit with running tap 

water.

1−3 (c) Removing the outer leaves on cabbages, lettuces, etc. 

D. In-kitchen produce-preparation options

Produce disinfection 2−3 Washing salad crops, vegetables and fruit with an appropriate 

disinfectant solution and rinsing with clean water.

Produce peeling 2 Fruits, root crops.

Produce cooking 6−7 Option depends on local diet and preference for cooked food. 

Sources: EPHC, NRMMC, and AHMC, 2006; WHO 2006; Amoah et al. 2011; modified from Mara et al., 2010
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9-16 2012 Guidelines for Water Reuse

9.4.2 Expanding and Optimizing Planned 

Water Reuse

As countries or municipalities in resource-constrained 

settings build operational and financial capacity, reuse 

safety should progress incrementally from on-farm and 

off-farm safety options to centralized or decentralized

wastewater treatment, while establishing sound 

regulatory and monitoring protocols (Von Sperling and 

Fattal, 2001; Drechsel and Keraita, 2010; and 

Scheierling et al., 2010). This step-wise approach, 

recommended by WHO (2006), provides local public 

health risk managers with flexibility to address 

wastewater irrigation risks with locally viable options 

matching their capacity within a multi-barrier 

framework (Figure 9-5), instead of struggling to 

achieve water quality threshold levels as the only 

regulatory option (Von Sperling and Chernicharo, 

2002). When treatment capacity has increased and 

irrigation water quality can be managed, the 

introduction of water quality standards should follow a 

similar incremental approach. The shift from water 

quality standards (WHO, 1989) to health-based targets 

(WHO, 2006), has helped to support a much broader 

range of measures for improving safe water reuse. 

Reuse schemes often evolve from household and 

decentralized systems to eventual centralized urban 

systems (Scheierling et al., 2010). However, it is 

important to remember that household and 

decentralized schemes may continue to be desirable 

in high-resource settings for some applications, such 

as graywater reuse for toilet flushing and sewer mining 

([Palestinian Territories-Auja] and [AustraliaGraywater]). The regulatory framework for reuse in 

these contexts should continue to support small-scale 

and potentially low-cost options where appropriate and 

where health and environmental risks can be 

minimized.

Wastewater quality regulations and standards from 28 

countries are compiled by GWI (2011). Common 

challenges associated with establishing and 

implementing standards, especially in countries with 

limited resources, are summarized in Table 9-5, along 

with recommendations to overcome these challenges. 

Appropriate technologies and practices for wastewater 

treatment for agricultural reuse are one way to reduce 

risks to public health where direct wastewater use is 

prevalent. There is a wide range of wastewater 

treatment options for safe water, nutrient recovery, and 

irrigation with particular relevance for resourceconstrained countries. Many experts in the field have 

summarized appropriate treatment options, including 

Mara (2004), Laugesen et al. (2010), Von Sperling and 

Chernicharo (2005), and Scheierling et al. (2010). As 

advances are made to drive down the cost of 

centralized and decentralized treatment technologies 

in resource-endowed contexts, some of the “high-tech” 

technologies, including MBR, may be adapted to 

lower-resource settings. Advances in decentralized 

wastewater treatment technologies and schemes may 

be particularly relevant in rapidly growing urban 

contexts where installation of centralized collection 

and treatment infrastructure is not cost-effective 

([Japan-Building MBR] and [Australia-Graywater]). 

However, decentralized systems are not a panacea 

where institutional capacities are generally low (Murray 

and Drechsel, 2011).

(Pictured left) The use of diluted untreated wastewater is prevalent in vegetable production in West Africa, such as here from a 

wastewater canal (Photo credit: IWMI). In the absence of wastewater treatment, possible pathogenic health risks from unsafe wastewater 

use could be reduced by implementing on-farm, post-harvest, and in-kitchen protection measures. (Pictured right) One on-farm option is 

the use of settling basins prior to irrigation. Comprehensive risk reduction is best achieved when multiple measures are used in 

combination. (Photo credit: Andrea Silverman)

Figure 9-4

Reducing the pathogenic health risks from unsafe use of diluted wastewater
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2012 Guidelines for Water Reuse 9-17

Table 9-5 Challenges and solutions for reuse standards development and implementation

Observation Recommendation

Guidelines, frequently copied from 

developed countries, are directly adopted 

as national standards.

Each country should adapt the guidelines, based on local conditions, and 

derive the corresponding national standards. In developed countries, these 

resulted from a long period of investment in infrastructure, during which 

standards were progressively improved. Cost and maintenance implications of 

too strict standards in the short term should be taken into account.

Guideline values are treated as absolute 

values, and not as target values.

Guideline values should be treated as target values, to be attained on a short, 

medium or long term, depending on the country’s technological, institutional or 

financial conditions. 

Treatment plants that do not comply with 

global standards do not obtain licensing or 

financing.

Environmental agencies should license and banks should fund control 

measures which allow for a stepwise improvement of water quality, even 

though standards are not immediately achieved. However, measures should be 

taken to effectively guarantee that all steps will be effectively implemented. 

There is no affordable technology to lead to 

compliance of standards.

Control technologies should be within the countries’ financial conditions. The 

use of appropriate technology should always be pursued.

Standards are not actually enforced. 

Standards should be enforceable and actually enforced. Standard values 

should be achievable and allow for enforcement, based on existing and 

affordable control measures. Environmental agencies should be institutionally 

well developed in order to enforce standards. 

Discharge standards are not compatible 

with water quality standards.

In terms of pollution control, the true objective is the preservation of the quality 

of the water bodies. Discharge standards should be based on practical (and 

justifiable) reasons, assuming a certain dilution or assimilation capacity of the 

water bodies.

Number of monitoring parameters are 

frequently inadequate (too many or too 

few). 

The list of parameters should reflect the desired protection of the intended 

water uses and local laboratory and financial capacities, without excesses or 

limitations.

There is no institutional development that

could support and regulate the 

implementation of standards.

The efficient implementation of standards requires an adequate infrastructure 

and institutional capacity to license, guide, and control polluting activities and to 

enforce standards.

Reduction of health or environmental risks 

due to compliance with standards is not 

immediately perceived by decision makers 

or the population.

Decision makers and the population at large should be well informed about the 

benefits and costs associated with the maintenance of good water quality, as 

specified by the standards. 

Figure 9-5

Multi-barrier approach to safeguard public health where wastewater treatment is limited (Amoah et al., 

2011)
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9-18 2012 Guidelines for Water Reuse

When transitioning from wastewater use to planned 

reuse, it is important to consider a country or city’s 

readiness to sustain investments in wastewater 

collection and treatment and the value added by 

treatment versus risk reduction through non-treatment 

barriers. There is no shortage of sanitation 

infrastructure that has fallen into disrepair, for 

example, and restrictions associated with reuse of 

treated wastewater has at times caused farmers to 

return to using untreated wastewater (Scheierling et 

al., 2010). It is therefore necessary to move toward 

planned reuse in a circumspect, phased approach 

whereby initial implementation is monitored for efficacy 

and sustainability before a larger-scale initiative is 

undertaken. Moving from wastewater use toward 

planned reuse requires a context-specific approach in 

light of institutional limitations and resource 

constraints. The following lessons of transitioning to 

wastewater collection, treatment, and reuse can be 

drawn from global experiences: 

Consider overall infrastructure needs. In many 

cities of the world without functioning wastewater 

collection systems, stormwater and wastewater flow 

through unlined engineered or natural drainage paths.

The cost of upgrading or constructing a collection 

system must be considered.

Consider local capacities. A key consideration in 

choosing appropriate treatment technologies is 

operator capacity. If a water reuse scheme is being 

planned and institutionalized at the municipality level, 

as exemplified in several case studies from India 

([India-Nagpur], [India-Delhi], and [India-Bangalore]), 

as opposed to a community or small institution scale 

([Palestinian Territories-Auja], [Israel/Peru-Vertical

Wetlands], and [Peru-Huasta]), a different set of 

technologies and practices will be appropriate and 

perhaps required in consideration of differing operator 

capacity, sophistication, and resource levels. 

Treatment and reuse schemes should therefore be 

designed to align with the social, environmental, 

technological, and economic circumstances of the 

target location/operator to achieve maximum 

sustainability (Von Sperling and Chernicharo, 2002; 

Nhapi and Gijzen, 2004).

Match treatment approach with reuse application 

at design stage. Several considerations should be 

taken into account when choosing an appropriate set 

of technologies to incorporate into the design of a 

planned reuse scheme. The treatment approach 

should be chosen to match the intended reuse 

application at the design stage rather than retrofitted 

after construction (Huibers et al., 2010; Murray and 

Buckley, 2010). This approach may represent a 

departure from conventional approaches that treat 

wastewater immediately to meet water quality 

standards for discharge to receiving waters. This goal 

may not be achievable where there is an existing

WWTP and no capability to convey treated wastewater 

directly to the reuse application. It also may not apply 

where the reuse application can only absorb a small 

amount of the discharged wastewater. However, 

where there is an opportunity to design a new facility 

with a reuse component, there is potential to achieve 

significant cost and energy savings by matching the 

level of treatment (and thus the investment in 

treatment technology and construction) to the intended 

reuse, as water quality standards for uses such as 

irrigation of forest plantations and cooling water for 

industrial processes may be much lower than 

standards for aquatic discharge. Also, for some 

irrigation applications it is necessary to reduce 

fertilization rates based on the increased nutrient 

content found in reclaimed water. Where possible, it 

will be important to implement a design flexible enough 

to accommodate future increases in demand for 

reclaimed water for the same application, as well as 

additional applications. This may require a phased 

approach to constructing treatment capacity and a 

design that does not preclude potential future 

treatment processes required for a broader range of 

water reuse applications. 

Consider overall costs and benefits. As highlighted 

in the Hyderabad Declaration of 2002, wastewater 

irrigation can have significant positive livelihood 

implications for poor smallholder farmers (EPA, 2004). 

These cost benefits can be considerable—even where 

wastewater is used without ideal treatment, especially 

in a low-resource context where households are facing 

multiple health risks. These economic benefits might 

outweigh health risks to the farmer and his/her family. 

Overly strict standards in these circumstances might 

be counterproductive, even for public health. In 

Ouagadougou and Lima, for example, farmers are not 

allowed to use treated wastewater as it does not meet 

ideal standards. As a result, farmers continue using 

untreated wastewater for crop production. 
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2012 Guidelines for Water Reuse 9-19

Where planned reuse is already being undertaken, 

there are at least two ways to strengthen its safety and 

sustainability for optimal benefits:

1. Transition to higher-value planned water reuse

2. Give greater consideration to environmental 

protection

Both options for strengthening planned water reuse 

imply moving beyond the WHO guidelines focus on 

protecting human health. The first point above calls for 

a shift from viewing treatment of wastewater as an 

obligation, either to protect human health or to satisfy 

environmental regulations, to viewing it as an 

opportunity to exploit a valuable economic resource. 

There is, indeed, growing recognition on the part of 

governments, from Arizona to Saudi Arabia, that the 

sale of treated wastewater can generate valuable 

revenues (GWI, 2010).

However, the greatest revenues come almost entirely 

from advanced water reuse applications, which require 

more advanced treatment and as such are better 

suited to applications other than agriculture. A major 

constraint to unlocking the market potential of water 

reuse are policies in many countries that force utilities 

to provide treated wastewater—even wastewater 

treated to an advanced level—to the agriculture sector. 

A major key to tapping the high value potential of 

water reuse, therefore, is overcoming strict 

government regulations and the public perceptions 

that often drive them, in order to open the domestic 

and industrial sectors to greater use for treated water 

(GWI, 2010).

It should be noted that liberalizing the allocation of 

reused water could result in a greater proportion of 

wastewater allocation to high-value, non-agriculture 

uses, possibly resulting in less water for agriculture. 

However, it is important to remember that this is not a 

zero-sum game. As highlighted above, there are large 

quantities of wastewater that are currently untreated 

and/or unused. It may very well be possible with 

treatment of growing volumes of wastewater, for 

example, to continue to provide reclaimed water to 

agriculture in addition to fostering increased reuse for 

higher-value applications, such as industrial and 

municipal applications.

Nonetheless, transitioning to higher-value uses can be 

hampered by the often low, subsidized price of 

Resource Recovery and Reuse: a 

Strategic Research Portfolio

An international research program addressing 

water reuse—Resource Recovery and Reuse 

(RRR) Strategic Research Portfolio—was 

recently launched by the Consultative Group 

on International Agricultural Research 

(CGIAR). The RRR research is part of the 

CGIAR’s strategic objective to enhance 

sustainable management of the natural 

resource base supporting agriculture to feed 

a rapidly growing global population. The first 

three-year budget (2011–13) is estimated at 

US$ 7 million and is coordinated by IWMI, a 

CGIAR center. USAID is one of several major 

donors to the CGIAR system.

The research under this theme will look at 

how to enhance the recovery of water, 

nutrients, organic matter, and energy from 

otherwise wasted resources for use in 

agriculture, serving two critically important 

goals. First, more nutrients and water will be 

available for use in agriculture even as the 

natural stocks of nutrients, such as 

phosphorus, become more expensive to 

mine. Second, the research will engage the 

private sector to identify opportunities for 

generating revenue that will support the 

sanitation service chain for the benefit of 

those exposed to poor sanitation and unsafe 

food. 

The research will explore existing, emerging, 

and potential business models; provide 

scientific guidance; and make policy 

recommendations to maximize the untapped 

potential for recovering water, essential 

nutrients, and biogas. At the same time, the 

research will promote safer and healthier 

practices when reusing waste materials on 

farms and when processing crops for 

consumption in local markets. 

Critically, the research will contribute to 

notable gains in food security by helping to 

alleviate water scarcity and restore nutrient 

losses on agricultural lands. 

For more information, see IWMI’s website on 

the research program: 

<www.iwmi.org/Topics/RRR> 
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9-20 2012 Guidelines for Water Reuse

drinking water, which drives down the sale price of 

recycled water, as well as the subsidized cost of 

sanitation and treatment services (Jimenez and 

Asano, 2008). Water pricing policies may need to be 

adopted that promote total water management, cost 

recovery of treatment, and service provision as a 

means of incentivizing water reuse. Comparing the 

cost of highly-treated recycled water with the price of 

highly-subsidized potable or irrigation water is an 

economic fallacy. This common comparison ignores 

both the numerous benefits inherent in water reuse 

and externalized costs of potable water under nearly 

all circumstances. The more appropriate comparison 

takes into account both sets of economic values and 

services using sophisticated quantification methods 

that go beyond simplistic benefit/cost ratios or priceversus-cost comparisons.

In addition to transitioning to higher-value uses, a 

second way to strengthen the safety and sustainability 

of planned water reuse is to give greater consideration 

to environmental protection, enhancement, and 

restoration. Indeed, countries may decide to graduate 

from the WHO model and address environmental 

concerns along with public health issues. In particular, 

water quality standards and guidelines for 

environmental flows may be instated to promote a 

desired level of treatment and volumes to divert for 

reuse. Standards are often set to reflect the degree of 

pathogen and contaminant removal possible with bestavailable treatment technologies. An overall regulatory 

strategy for water reuse is typically driven by the 

economics of treatment and monitoring, as well as 

enforcement capacity (Jimenez and Asano, 2008). In 

the agricultural sector, water quality standards for 

water reuse on export crops may also be influenced by 

standards required by the importing countries or 

regions. These improvements would build on previous 

low-cost steps to reduce public health risks and toxic 

contamination at the source, as outlined in the 

Hyderabad Declaration (IWMI and International 

Development Research Centre, 2002). 

9.5 Factors Enabling Successful 

Implementation of Safe and 

Sustainable Water Reuse 

Global experiences have demonstrated that choosing 

an appropriate set of technologies or regulations is not 

in itself sufficient to ensure the safety and 

sustainability of a given water reuse project, especially 

under resource-constrained conditions. A set of factors 

must be established to support the long-term 

functioning of the water reuse program to achieve 

sustainability. Some of these factors are discussed in 

this section. 

Stakeholder process. Although participatory 

processes can take more time compared with lessparticipatory approaches, risk of failure will be reduced 

by explicit integration of all relevant institutions and 

stakeholders in the planning and design phases of 

water reuse schemes. This applies in particular to 

water reuse in agriculture, which links different sectors 

(sanitation, agriculture, health, and environment). 

While regulatory frameworks that govern wastewater 

treatment and reuse schemes are typically crafted at 

the national or regional level of government, it is 

usually the responsibility of local or municipal 

institutions to implement the programs, including longterm financing, cost recovery, operations and 

maintenance, and performance monitoring. In the case 

of Ghana, for example, treatment plants at universities, 

hospitals, and military camps were operated by the 

Ministries of Education, Health, and Defense, 

respectively (Murray and Drechsel, 2011). This places 

a significant responsibility on local institutions without 

ensuring their improved capacities. National-level 

frameworks are indeed a key enabling factor, as 

illustrated in the Nagpur, India case study [IndiaNagpur]. 

Another critical element of the multi-stakeholder 

planning process is involving the end users in the 

planning and design phases. If end-user preferences 

for reclaimed water volumes and quality are not taken 

into account during the planning phase, the end users 

may not be able to make full use of the provided water 

or may refuse to pay for the service. Also, the 

treatment technology selected for the project should 

consider local experience in what works and what 

does not. Involving representatives from the 

communities that both supply and use the treated 

water will facilitate negotiations and “water swaps.” For 

example, farmers may be willing to transfer a portion 

of their freshwater allocations to meet urban water 

demand if they are provided access to treated, 

nutrient-rich, and reasonably-priced reclaimed water 

for agricultural activities (Winpenny et al., 2010; 

Huibers et al., 2010). Transitioning from a traditional 

top-down approach to a user-centered approach for 

planning and design has the potential to achieve more 
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2012 Guidelines for Water Reuse 9-21

sustainable outcomes. This approach is described 

further in Chapter 8.

Sustainable Financial and Institutional Capacity 

Management. Forward-minded consideration of 

financing and capacity building is critical to 

sustainability. Operation and maintenance costs are 

often underestimated, and high staff turnover is a key 

challenge of public sector projects such as those 

related to water reuse. These factors often drive a runto-failure trajectory (Murray and Drechsel, 2011). 

Development of a longer-term strategy and/or 

involvement of the private sector could help avoid such 

an outcome. Although WWTPs are often publicly 

financed, the public-private partnership model is being 

piloted (e.g., Scheierling et al., 2010; Murray et al., 

2011). An example of cost-recovery is the use of 

treatment ponds for aquaculture in Ghana (Waste 

Enterprisers, 2012).

Public Outreach. A successful and sustainable water 

reuse program must integrate a public involvement 

campaign, particularly where the involved public will be 

consumers of the reclaimed water or the product 

developed using the reclaimed water. This is 

described further in Chapter 8. Just as a water reuse 

project may fail due to a lack of early stakeholder 

involvement, failure to garner public acceptance of 

water reuse through a well-conceived and 

implemented communication campaign can limit 

market demand for the product. There are several 

good examples of public acceptance campaigns for 

water reuse associated with potable reuse [SingaporeNEWater] and [India-Bangalore], irrigation [SpainCosta Brava], [Palestinian Territories-Auja], 

[Israel/Peru-Vertical Wetlands], and industrial reuse 

[India-Nagpur]. Public outreach will be more 

challenging where risk awareness is low or hazards of 

multiple origins (water-borne, food-borne) affect 

households, such as in many low-resource settings. In 

these circumstances, a significant investment in risk 

education is required. Lessons can be learned from 

hand-washing campaigns. 

9.6 Global Lessons Learned About 

Water Reuse

There are key themes emerging in the global dialogue 

on water reuse that are of relevance to the United 

States and that merit discussion; regardless of the 

context of reuse, there are common challenges.

We have a common challenge. Pressure on the 

world’s water resources has been growing 

dramatically, and climate change is accentuating 

patterns of droughts and floods. Water scarcity is 

affecting communities around the world, presenting an 

incredible opportunity for collaboration. And as 

solutions are developed in one context, they can be 

adapted to new contexts. For example, the U.S. is one 

of the world’s leaders in advanced water reclamation 

technologies and stands to benefit from taking 

advantage of low-cost, low-energy solutions being 

demonstrated as described in several case studies 

from outside of the U.S. [Brazil-Car Wash], 

[Israel/Peru-Vertical Wetlands], [Philippines-Market]. 

Likewise, advances in salinity management and drip 

irrigation in agricultural reuse is a key topic for 

scientific exchange between the United States and 

countries in the Middle East and other arid regions. 

The world has learned a great deal from Singapore’s 

advanced reuse technology as well as its leadership in 

integrated management and holistic planning under its 

long-term water supply strategy called “Four National 

Taps.” Regulators in the United States have gained 

insight from the experience of other countries setting 

national guidelines and regulations, notably Australia. 

Current challenges in reuse, including economic 

models for partial or full cost recovery and technical 

challenges in nutrient recovery and energy efficiency, 

are also opportunities for international exchange. 

Multi-purpose reuse. Some of the reuse projects 

described in the international case studies are multipurpose programs, where reclaimed water within one 

system is treated to different water quality standards to 

supply reclaimed water to an array of end uses. In 

contrast, most water reuse applications in the United 

States are designed for water reuse for a singular 

purpose. Multi-purpose systems may be more robust 

and adaptable than single-use applications, and new 

installations in the United States might take note from 

successes in other regions of the world.

Fine tuning the treatment. The concept of “fit-forpurpose” is illustrated dramatically in many of the 

international reuse case studies ([AustraliaReplacement Flows], [Brazil-Car Wash], [ColombiaBogota], [India-Nagpur], [South Africa-eMalahleni 

Mine], and [South Africa-Durban]). In these reuse 

installations, careful study was conducted to ensure 

that the water produced would have the appropriate 

water quality for the intended use. Water reuse market 
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9-22 2012 Guidelines for Water Reuse

growth is projected to take this approach—designing 

reuse for a specific purpose to achieve economic 

efficiency. Both high- and low-tech solutions are 

imminently relevant to tuning our approaches, and as 

mentioned above, multiple endpoints may be 

appropriate for multi-purpose systems. Global 

experiences can help reuse planners answer the 

following questions: Are we choosing the easiest 

solution or the best solution? How carefully have the 

options been weighed?

Increasing dialogue about water reuse in all 

corners of the world. Confidence in water and 

wastewater treatment technologies has grown among 

scientists and engineers, regulators, and increasingly, 

the general public such that the public and the 

decision-makers have security in the safety of 

reclaimed water. As the market grows, public 

awareness will increase, which has been shown to 

improve acceptance of and investment in reuse. 

Countries with only emerging wastewater collection 

and treatment systems will benefit from this dialogue if 

their opportunities and constraints are taken into 

account. The case studies show an encouraging 

spectrum of options where increased sanitation and 

wastewater management efforts in resourceconstrained countries can move unplanned 

wastewater use to planned reuse, while taking 

advantage of modern treatment and non- or posttreatment options for safeguarding public health. With 

increasing population pressures for more available 

water resources, increasing recovery of the water 

resource from wastewater can help in meeting the total 

water needs of many nations.

9.7 References

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Realities, November 11-14, 2002, Hyderabad, India.

Jiménez, B., P. Drechsel, D. Koné, A. Bahri, L. RaschidSally, and M. Qadir. 2010. “Wastewater, Sludge and Excreta 

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2011.
2012 Guidelines for Water Reuse A-1 

APPENDIX A 

Funding for Water Reuse Research

A.1 Federal Agency Reuse Research

Several federal agencies provide funding for various 

aspects of water reuse research, including EPA, 

USAID, U.S. Bureau of Reclamation (USBR), USDA, 

U.S. Geological Survey (USGS), the Centers for 

Disease Control and Prevention (CDC), the 

Department of Energy (DOE), and the National 

Science Foundation (NSF). The only agency with a 

specific directive driving research in water reuse is 

USBR, which is focused mainly on water quantity. 

EPA’s research looks at water quality, while DOE’s 

research examines the energy requirements of water 

reuse. USDA focuses on the benefits of water reuse in 

agriculture. USDA, CDC, and USGS fund research 

examining public health and water reuse. USAID’s 

research targets water reuse as a component of 

sustainable development in developing countries and 

as a collaboration tool for developing peace and 

security between nations. NSF funds water reuse 

research around the themes of water treatment 

technology and infrastructure renewal.

A.1.1 EPA 

Water reuse is relevant to the water elements of EPA’s 

2011-2015 Strategic Plan (EPA, N.D.), which include 

strengthening water quality standards, adoption of 

sustainable management practices, and promoting 

innovative, cost-effective practices to protect water 

quality. EPA has many ongoing efforts related to water 

reuse, with no single lead office on the topic. Research 

that supports water reuse includes EPA’s program on 

human health effects of chemicals (using screening 

and laboratory studies) and pathogens (using 

epidemiological data). Advances in analytical methods 

and monitoring are supported through research with 

the Unregulated Contaminant Monitoring Rule (UCMR) 

program. The program also collects and analyzes data 

on the occurrence of endocrine-disrupting chemicals in 

the environment to better understand human health 

and environmental effects (NRC, 2012). 

A.1.2 USAID 

USAID has a major programmatic focus on integrated 

water resources management and in water and 

sanitation for health in developing countries. USAID 

has sponsored projects to implement nonpotable water 

reuse projects in India, Jordan, Morocco, Philippines, 

Thailand, and West Bank/Gaza, as illustrated in 

several case studies. 

USAID also provides some funding for water reuse 

research in three different programmatic areas. First, 

USAID supports the Consultative Group on 

International Agricultural Research (CGIAR), which is 

global partnership that unites organizations engaged in 

research for sustainable development. Part of the 

CGIAR research portfolio includes research in the area 

of water reuse and resource recovery. This research is 

described further in Chapter 9 in the text box 

“Resource Recovery and Reuse: a Strategic Research 

Portfolio.”

USAID’s Middle East Research Cooperation Program 

(MERC) was created in 1979 to promote Arab-Israeli 

cooperation through joint applied research projects; 

and to contribute to the peace process through the 

establishment of cooperative relationships that will last 

beyond the life of the projects. As part of its portfolio of 

research, MERC has funded peer-reviewed 

cooperative projects in the areas of agriculture, health, 

environment, economics, and engineering, including 

wastewater treatment and water reuse. Case studies 

from Israel, Jordan, and West Bank/Gaza include 

examples of MERC-funded projects [Israel/JordanAWT Crop Irrigation; Israel/Palestinian 

Territories/Jordan-Olive Irrigation; Israel/JordanBrackish Irrigation].

USAID’s U.S.-Israel Cooperative Development 

Research (CDR) Program was created in 1985 to 

support joint research projects between Israeli (and 

U.S.) scientists with their counterparts in developing 

countries around the globe to address problems 

facing the developing-country partners. Each project’s 

budget is spent primarily on capacity-building 

measures in the participating developing country such 

as student training, essential equipment and outreach. 

As part of its portfolio of research, CDR has funded 

peer-reviewed cooperative projects in the areas of 

agriculture, health, and environment, including 

wastewater treatment and water reuse. CDR is, 
Appendix A | Funding for Water Reuse Research

A-2 2012 Guidelines for Water Reuse

however, presently closed to new applications. A CDR 

case study from Israel and Peru is included [Case 

study: Israel/Peru - Vertical Wetlands].

A.1.3 USBR 

The only federal agency with a directive to fund water 

reuse research is USBR. The USBR water reclamation 

and reuse program is authorized by the Reclamation 

Wastewater and Groundwater Study and Facilities Act 

of 1992 (Title XVI of Public Law 102-575) (USBR, 

2009). Also known as Title XVI, the act directs the 

Secretary of the Interior to undertake a program to 

investigate and identify opportunities for water 

reclamation and reuse of municipal, industrial, 

domestic and agricultural wastewater, and naturally 

impaired ground and surface waters, and for design 

and construction of demonstration and permanent 

facilities to reclaim and reuse wastewater. It also 

authorized the Secretary to conduct research, 

including desalting, for the reclamation of wastewater 

and naturally impaired ground and surface waters. 

Currently, funding is used for demonstration and 

desalination projects and the WateReuse Research 

Foundation. Reclamation’s partnership with the 

WateReuse Research Foundation funds applied 

research in the areas of water reclamation, reuse and 

desalination. Both solicited and unsolicited projects are 

funded for cutting edge research that expands the 

water and wastewater communities knowledge in a 

wide range of subjects, which include: chemistry and 

toxicology; desalination and concentrate management; 

microbiology and disinfection; natural systems, 

groundwater recharge, storage; policy, social 

sciences, and applications; treatment technologies. 

The Foundation is funded primarily by a group of 

subscribers, which typically include: water and 

wastewater utilities, consulting firms, equipment 

suppliers and other organizations. Reclamation’s 

financial contributions supplement these subscriber 

funds.

Active reclaimed water research funded by the 2008 

National Irrigation Water Quality Program (NIWQP) of 

USBR sought to develop tools and guidelines for risk 

management decisions based on the microbial 

monitoring of surface derived irrigation water and 

assessing potential risks from using treated effluent for 

irrigation of food crops in the Lower Colorado River 

Basin. Project directors are finalizing the determination 

of the variation and environmental factors affecting the 

microbial risks from reclaimed irrigation water, 

identifying relationships among total fecal coliform, 

generic E. coli, and E. coli O157:H7 in irrigation water 

and corresponding levels found in irrigated vegetables, 

shaping criteria needed to estimate cumulative risk of 

reclaimed irrigation water followed by appropriate 

testing and decision tools, assess the microbial risk, 

and conduct an aggressive outreach program to 

implement irrigation water risk assessment 

management practices.

A.1.4 USDA

USDA has interest in water reuse as an alternative 

reliable supply of water for irrigation. USDA currently 

funds research on the potential health and agricultural 

sector effects of using reclaimed water for crops. 

USDA/NIFA has made funding for water reuse 

research, education, and extension one of its priorities. 

As a result of the 2005 Agricultural Water Security 

Listening Session (Dobrowolski and O’Neill, 2005), 

NIFA (formerly the Cooperative State Research, 

Education and Extension Service, CSREES) chose to 

develop three research, education, and extension 

themes. These three themes—biotechnology, 

conservation, and reclaimed water—fit within the 

research and education challenges (water availability, 

quantity and quality, water use, and water institutions) 

described by the National Research Council (2004). 

Subsequent to the 2005 session, NIFA sponsored two 

specialty conferences in 2007 and 2008 in partnership 

with the WateReuse Association titled “Water Reuse in 

Agriculture Opportunities and Challenges” and “Water 

Reuse in Agriculture Ensuring Food Safety.” The 

purpose of the conferences is to provide a forum for 

discussion, collaboration, and coordinated funding in 

reclaimed water among USDA agencies and 

others. More recently, the Research, Education, and 

Economics mission area of USDA drafted a Strategic 

Action Plan with water as a sub-goal and recycled 

water in agriculture as an action item for both research 

agencies. This included a commitment to invest in 

research, development, and extension of new irrigation 

techniques and management of limited water 

resources, including strategies for water reuse. NIFAfunded research includes studies on impacts of 

reclaimed water on plants and soils, treatment 

methods to prevent impacts to soils, long-term effects 

of irrigating with reclaimed water, minimizing food 

safety hazards, and fate of pharmaceuticals and 

hormones in agricultural production. 
Appendix A | Funding for Water Reuse Research

2012 Guidelines for Water Reuse A-3 

USDA/NIFA’s Agriculture and Food Research Initiative 

(AFRI) Foundational program in 2010 funded six 

projects currently investigating the bioaccumulation 

and potential contamination of reclaimed water 

constituents applied at typical irrigation rates used 

exclusively or through blending with surface and 

ground water sources. NIFA awarded these projects 

competitively, evaluated by peer-review panels. 

Scientists focused their studies on six issues: 

 The bioaccumulation of pharmaceutical and 

personal care products (PPCPs) by common 

vegetables and fruit (lettuce, cabbage, bell 

pepper, tomato, carrot, parsley, radish, and 

strawberry) in both field and greenhouse 

hydroponic experiments irrigating with treated

wastewater. 

 The dose-dependent bioaccumulation of 

chemicals of emerging concern (CEC) assessed 

in both laboratory and field studies with 

reclaimed water fortified with CECs; subsequent 

studies will examine the effects of soil organic 

matter and cumulative use of recycled water on 

selected crops eaten fresh. 

 The uptake of reclaimed water chemicals from 

irrigation of commonly grown vegetable crops 

with water containing several isotopically 

labeled chemicals, using a range of irrigation 

regimens to simulate varying degrees of water 

stress. 

 The integration of hydroponic, column, and 

greenhouse studies to evaluate bioaccumulation 

of antimicrobials by food crops with fate 

modeling and risk assessment to determine 

relevance; with results synthesized into an 

assessment of health risk from antimicrobial 

exposure through food, water, and reclaimed 

water use. 

 The minimization of antibiotic resistant (ABR) 

Salmonella in vegetables irrigated with 

reclaimed water; identifying the fate of ABR 

Salmonella in soil and lettuce after irrigation, 

and developing best management practices 

both lowering pathogen levels through blending 

water source and avoiding using reclaimed 

water at critical stages of plant growth, to 

minimize accumulation in lettuce.

 The clear understanding of the fate and 

potential bioaccumulation of estrogenic 

chemicals (endocrine disrupting compounds, 

EDCs) within the edible portion of crop plants 

through root and foliar exposure followed by sap 

flow and plant extraction methodologies; results 

will be useful for predicting bio-concentration 

potential, potential dietary intake, and risks to 

human health.

NIFA also collects annual information on the extent of 

the use of reclaimed water in irrigation in an annual 

inventory of farms conducted by its National 

Agricultural Statistics Service (NRC, 2012). This 

research will provide a more in-depth understanding of 

the impacts of long-term water reuse on the nation’s 

agricultural sector.

A.1.5 USGS 

USGS supports water reuse research through its 

Water Census, aquifer storage and recovery (ASR) 

program, and program on the occurrence of humanuse compounds in the nation’s surface waters. The 

Water Census is nation-wide accounting of water 

supplies and water use in the United States, which is 

cited in Chapter 5 for each region of the United States. 

The ASR research program looks at how geochemistry 

changes with subsurface storage of water. USGS’s 

surface water program has also conducted extensive 

research on the occurrence, pathways, uptake, and 

effects of these human-derived contaminants, 

including from wastewater (NRC, 2012).

A.1.6 CDC 

The CDC has supported research on water reuse as a 

means to protect human health during drought 

conditions and a research project to enhance capacity 

to investigate links between wastewater, groundwater 

contamination, and human health (NRC, 2012).

A.1.7 DOE 

As part of DOE’s National Energy Technology 

Laboratory’s efforts to reduce water demands in 

energy production, DOE is conducting research on the 

technical, financial, and long-term challenges and 

benefits associated with using reclaimed wastewater 

for power plant cooling (NRC, 2012).

A.1.8 NSF

NSF sponsors one fifth of the water resources

research in the United States (NRC, 2004), but does
Appendix A | Funding for Water Reuse Research

A-4 2012 Guidelines for Water Reuse

not have a specific funding emphasis on water reuse.

Water reuse is a consideration under many of the 

urban/suburban focused “Water Sustainability and 

Climate” grants, a new NSF initiative. The goal of 

these grants is to assess the overall impact of 

decisions about water resources, including 

downstream impacts on water quality. An NSF-funded 

center on water treatment technology (the Center of 

Advanced Materials for the Purification of Water with 

Systems (WaterCAMPWS) includes research related 

to water reuse technologies (NRC, 2012). Another 

NSF-funded engineering research center ReNWUIt 

brings together environmental engineering, earth 

sciences, hydrology, ecology, urban studies, 

economics, and law to address the nation’s urban 

water infrastructure. 

A.2 Non-Governmental Organization 

(NGO)-Sponsored Research

Several U.S.-based and international NGOs sponsor 

research in water reuse.

A.2.1 Global Water Research Coalition 

(GWRC)

The GWRC is a collaboration between 12 research 

organizations around the globe, with partnership from 

EPA. The GWRC aims to leverage funding and 

expertise toward water quality research of global 

interest (NRC, 2012).

A.2.2 National Water Research Institute

The National Water Research Institute (NWRI) 

supports research and outreach related to ensuring 

clean and reliable water. NWRI was founded in 1991 

and has six member organizations, all based in 

Southern California. NWRI has invested over $17 

million in research, largely focused on water reuse 

since its member organizations have strong interest in 

sustainable water solutions. Research has included 

disinfection guidelines for water reuse, the fate and 

transport of trace organic contaminants, subsurface 

transport of bacteria and viruses, and use of bioassays 

and monitoring to assess trace contaminant removal in 

water reuse (NRC, 2012).

A.2.3 Water Environment Research 

Foundation

The Water Environment Research Foundation (WERF) 

is a subscriber-based organization that funds 

wastewater- and stormwater-related research. 

WERF’s areas of active water reuse research include: 

 Advanced wastewater treatment processes for 

removal of trace organic compounds

 Fate and transport of trace organic chemicals in 

treated municipal wastewater used for turf 

irrigation

 Demonstration of membrane zero liquid 

discharge technologies as a long-term solution 

for concentrate disposal following municipal 

wastewater treatment

 Demand, waste and cost estimation tools for 

urban water management

 Source separation of household graywater from 

blackwater for graywater reuse

 Fate and transport of chemical and pathogen 

constituents in household graywater used for 

landscape irrigation

 Technologies and practices for sustainable 

stormwater reuse

A.2.4 WateReuse Research Foundation 

The WateReuse Research Foundation is an 

educational, nonprofit public benefit corporation that 

serves as a centralized organization for the water and 

wastewater community to advance the science of 

water reuse, recycling, reclamation, and desalination. 

The Foundation funds research covering a broad 

spectrum of issues, including chemical contaminants, 

microbiological agents, treatment technologies, salinity 

management, public perception, economics, 

marketing, and industrial reuse. 

The Research Foundation's primary sources of 

funding are its subscribers and its funding partners, 

which include the Bureau of Reclamation, the 

California State Water Resources Control Board, and 

the California Energy Commission. The Foundation's 

subscribers include water and wastewater agencies 

and other interested organizations. The Foundation is 

committed to pursuing new partners to collaborate on 

research and leverage resources.

Full reports are available for purchase through the 

WateReuse Research Foundation website 

(http://www.watereuse.org/foundation/publications). 
Appendix A | Funding for Water Reuse Research

2012 Guidelines for Water Reuse A-5 

A.2.5 Water Research Foundation

The Water Research Foundation (formerly known as 

the American Water Works

Association Research Foundation) supports applied 

research related to drinking water. The Water 

Research Foundation is a subscriber-based 

organization. Water reuse-related research has 

included research on soil aquifer treatment and on 

trace organic contaminants in drinking water, including 

assessment of exposure, improvements in analytical 

methods, and improved frameworks for risk 

communication for utilities (NRC, 2012).

A.3 Research Funding Outside the U.S. 

This section describes government initiatives in 

Australia, Egypt, and Qatar to fund water reuse 

research. Though this is not meant to be 

comprehensive of global efforts; instead it illustrates 

the interest in water reuse by many countries around 

the world. 

A.3.1 Australian Federal Funding 

In Australia, water reuse (generally referred to as 

water recycling in Australia) has been growing at 

around 10% per year over the past 5 years. Rapidly 

growth in investment in reuse began in the mid 2000s, 

partially in response to a dry period from 2001 to 2009. 

For urban areas the greatest value of water reuse is 

attached to replacement of potable demand. 

Concurrent with the rapid investment in water reuse 

projects, state and federal government agencies, 

water utilities, research institutions and the broader 

water sector embarked upon a rapid increase in water 

reuse research. There were two major driving forces 

behind this increased research investment. 

First, national health and environmental guidelines 

were developed for potable and non-potable water 

reuse. In response to conservative targets based on 

existing data, regulators and utilities soon identified a 

range of research needs to manage and reduce 

treatment costs while ensuring that risk management 

and prevention remained the critical underpinning of 

water reuse projects. 

Second, politics around potable reuse drove 

investments in research. In a referendum in 

Toowomba, Queensland in 2006, the community voted 

against potable reuse to alleviate their water supply 

problems. This highlighted the need for greater 

community engagement and how political water 

decisions could be. Just a few years later, having 

spent billions on an indirect potable reuse scheme in 

South East Queensland, elected officials decided at 

the last minute to set very conservative requirements 

to introduce highly purified water into the local surface 

reservoirs that would not be reached for many years 

and beyond the subsequent few electoral cycles. 

Again, potable reuse had been stymied by politics.

This background leads to the current state of water 

reuse research in Australia which is well funded and is 

addressing the highest priority issues:

1. The Federal Government has provided $20

million dollars (over 5 years) to develop a 

Centre of Excellence. The Australian Water 

Recycling Centre of Excellence is now half way 

through its term and has 4 major research goals 

encompassing community and stakeholder 

acceptance of potable reuse, developing a 

national framework for validation of treatment 

technologies, a program of projects dedicated to 

understanding and measuring the sustainability 

of water recycling, and development of skills 

and capability in managing the complexity of 

water reuse projects from a planning, 

technological and operational perspective.

2. Water utilities have had an ongoing research 

program working both collaboratively through 

Water Services Association of Australia, Water 

Quality Research Australia and through local 

and state based Research collaborations 

including the Smart Water Fund in Victoria and 

the Urban Water Security Research Alliance in 

Queensland. These collaborative research 

programs continue to generate highly valued 

research in water quality, health and ecosystem 

protection and sustainability analysis. Water 

utilities also undertake their own research on 

water reuse covering issues such as treatment 

technology and validation and customer and 

community research.

3. More recently, the Federal Government has 

provided multi million dollars of funding over 8 

years to a Cooperative Research Centre on 

Water Sensitive Cities which, inter alia, will be 

addressing the next frontier of water reuse, the 

safe and sustainable use of storm water 

harvesting. This large national collaboration 
Appendix A | Funding for Water Reuse Research

A-6 2012 Guidelines for Water Reuse

brings together researchers, industry, 

governments and utilities to research 

approaches to urban water management that 

encompass traditional water supplies, water 

reuse from sewage, graywater and storm water 

and the integration of desalinated supplies. 

Other research entities funding water reuse research 

in Australia include the National Groundwater Centre 

of Excellence and the Commonwealth Scientific and 

Industrial Research Organisation (CSIRO), Australia's 

national science agency. These entities undertake 

water reuse research under contract or through 

strategic partnerships. In addition, in 2012 the 

Australian Water Recycling Centre of Excellence 

(AWRCE) announced Aus$ 3 million (US$ 3 million) 

for a research project to investigate and address the 

barriers to public acceptance of reusing water for 

augmenting drinking water supplies. 

A.3.2 Egypt National Water Research 

Center (NWRC)

Egypt’s NWRC funds research on drainage water 

reuse that is conducted by the Drainage Research 

Institute (one of the NWRC twelve institutes), through 

its governmental budget. Research areas under this 

topic include drainage water quantity and quality 

monitoring and assessment and simulation of national 

drainage water reuse policy in the context of integrated 

water resources management of the Nile Delta. The 

NWRC also provides guidelines for drainage water 

reuse in irrigating old and newly reclaimed lands.

A.3.3 Qatar National Research Fund 

(QNRF) and Qatar Water Sustainability 

Center

The purpose of the Qatar National Research Fund 

(QNRF) is to foster a research culture in Qatar. Water 

reuse is one of the research areas identified as 

relevant to Qatar’s national needs, based on an 

internal study commissioned by Qatar Foundation after 

consultation with a variety of relevant stakeholders in 

Qatar. The Global Water Sustainability Center will 

work with industrial and municipal organizations in 

Qatar to promote water recycling and reuse. 

References

Dobrowolski, J.P. and M.P. O’Neill. 2005. Agricultural Water 

Security Listening Session Final Report. USDA REE. 

Washington, D.C.

National Council for Science and the Environment. 2004. 

Water for a Sustainable and Secure Future: A Report of the 

Fourth National Conference on Science, Policy and the 

Environment. Washington, D.C.

National Research Council (NRC). 2004. Confronting the 

Nation’s Water Problems: The Role of Research. National 

Academies Press: Washington, DC.

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.

U.S. Bureau of Reclamation. (USBR) 2009. Title XVI (Water 

Reclamation and Reuse) Program. Retrieved July 31, 2012. 

<http://www.usbr.gov/lc/socal/titlexvi.html>. 

U.S. Environmental Protection Agency (EPA). N.D. An 

Introduction to the Water Elements of the EPA’s Strategic 

Plan. Retrieved July 31, 2012. 

<http://water.epa.gov/aboutow/goals_objectives/goals.cfm>. 
2012 Guidelines for Water Reuse B-1 

APPENDIX B 

Inventory of Recent Water Reuse Research 

Projects and Reports

Project 

Number Publication Date Title Organization

- 2009

Sustainable Wastewater Management in Developing 

Countries: New Paradigms and Case Stories from the 

Field

American Society of 

Civil Engineers

- 2009 Planning for the Distribution of Reclaimed Water AWWA

- 2012 (prepublication)

Assessment of Water Reuse as an Approach for 

Meeting Future Supply Needs AWWA

- 

Advanced Oxidation of Pharmaceuticals and Personal 

Care Products: Preparing for Indirect and Direct Water 

Reuse

AWWA

- 2008 Survey of High Recovery and Zero Liquid Discharge 

Technologies for Water Utilities AWWA

- 2008 Regional Solutions for Concentrate Management AWWA

- 2008 The Impacts of Membrane Process Residuals on 

Wastewater Treatment: Guidance Manual AWWA

- 2011

Membrane Treatment of Impaired Irrigation Return and 

Other Flows: Creating New Sources of High Quality 

Water

AWWA

- Research Strategy for Water Reuse Workshop AWWA

- 2008 Inland Membrane Concentrate Treatment Strategies for 

Water Reclamation Systems AWWA

- 2008 Design, Operation and Maintenance for Sustainable 

Underground Storage Facilities AWWA

- 2007 Comparing Nanofiltration and Reverse Osmosis for 

Treating Recycled Water AWWA

- 2009 Water Quality Changes During Aquifer Storage and 

Recovery AWWA

- 2006 Organic Nitrogen in Drinking Water and Reclaimed 

Water AWWA

- 2004 Industrial Water Quality Requirements for Reclaimed 

Water AWWA

- 2005 Water Quality Improvements During Aquifer Storage 

and Recovery AWWA

- 2003 ASR in Wisconsin Using the Cambrian-Ordovician 

Aquifer AWWA

- 2003 Comparison of Alternative Methods of Recharge of a 

Deep Aquifer AWWA

- 1996 Aquifer Storage and Recovery of Treated Drinking 

Water AWWA

- 2002 and 2006 Investigation of Soil-Aquifer Treatment for Sustainable 

Water Reuse AWWA

- 1998 Issues with Potable Reuse: The Viability of Augmenting 

Drinking Water Supplies with Reclaimed Water AWWA

- 2004 Industrial Water Quality Requirements for Reclaimed 

Water

AWWA Research 

Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

B-2 2012 Guidelines for Water Reuse

Project 

Number Publication Date Title Organization

- 2007 Removal of EDCs and Pharmaceuticals in Drinking and 

Reuse Treatment Processes

AWWA Research 

Foundation

- 2006 Characterizing and Managing Salinity Loadings in 

Reclaimed Water Systems

AWWA Research 

Foundation

94-PUM-1CO 1998 Soil Treatability Pilot Studies to Design and Model Soil 

Aquifer Treatment Systems AWWA/WERF

- 2010 Whitepaper on Graywater AWWA/WERF/

WateReuse Foundation

- 2009 Technical Memorandum on Gray Water Black and Veatch

- 2005 Water Reuse for Irrigation: Agriculture, Landscapes, 

and Turf Grass

Chemical Rubber 

Company Press

- 2006 Growing Crops with Reclaimed Wastewater CSIRO Publishing

- 2009 Sustainable Water for the Future, Volume 2: Water 

Recycling Versus Desalination 

Elsevier, Amsterdam 

Netherlands

- 2010 Municipal Water Reuse Markets 2010 Global Water Intelligence

- 2012 Water-Energy Interactions in Water Reuse International Water 

Association

- 2008 Water Reuse: An International Survey of Current 

Practice, Issues and Needs

International Water 

Association

- 2012

Sustainable Treatment and Reuse of Municipal 

Wastewater for Decision Makers and Practicing 

Engineers

International Water 

Association

- Milestones in Water Reuse: The Best Success Stories International Water 

Association

- 2006 Water Reuse: Issues, Technologies, and Applications McGraw-Hill

- 2012 Water Reuse: Potential for Expanding the Nation's 

Water Supply through Reuse of Municipal Wastewater

National Research 

Council

- 2011 Water Recycling and Water Management (Water 

Resource Planning, Development and Management) Nova Science Publishers

- 2011 Onsite Residential and Commercial Water Reuse 

Treatment Systems NSF

- Jan-12

Direct Potable Reuse: Benefits for Public Water 

Supplies, Agriculture, the Environment, and Energy 

Conservation

NWRI

- Apr-10 Regulatory Aspects of Direct Potable Reuse in 

California NWRI

- 2008 Efficient Management of Wastewater: Its Treatment 

and Reuse in Water-Scarce Countries

Springer-Verlag, Berlin 

Germany

- 2011 Waste Water Treatment and Reuse in the 

Mediterranean Region

Springer-Verlag, Berlin 

Germany

- 2009

Development of Indicators and Surrogates for Chemical 

Contaminant Removal During Wastewater Treatment 

and Reclamation

Water Environment 

Research Foundation

- 2006 Advances in Soil Aquifer Treatment Research for 

Sustainable Water Reuse

Water Environment 

Research Foundation

- 2007 Towards an Innovative DNA Array Technology for 

Detection of Pharmaceuticals in Reclaimed Water

Water Environment 

Research Foundation

- 2005 Membrane Treatment of Secondary Effluent for 

Subsequent Use

Water Environment 

Research Foundation

- 2006 Long-Term Effects of Landscape Irrigation Using 

Household Graywater

Water Environment 

Research Foundation

- 2011 Guidance Manual for Separation of Graywater from 

Blackwater for Graywater Reuse

Water Environment 

Research Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

2012 Guidelines for Water Reuse B-3 

Project 

Number Publication Date Title Organization

- 2004 Evaluation of Microbial Risk Assessment Techniques 

and Applications

Water Environment 

Research Foundation

- 2008 Using Reclaimed Water to Augment Potable Water 

Resources

Water Environment 

Research Foundation

92-WRE-1 - Water Reuse Assessment Water Environment 

Research Foundation

92-HHE-1-CO Use of Reclaimed Water ad Sludge in Food Crop 

Production

Water Environment 

Research Foundation

97-IRM-6 - Non-Potable Water Reuse Management Practices Water Environment 

Research Foundation

98-CTS-1 - Research Needs to Optimize Wastewater Resource 

Utilization

Water Environment 

Research Foundation

98-CTS-5 - Feasibility and Application of Membrane Bioreactor 

Technology for Water Reclamation

Water Environment 

Research Foundation

98-HHE-1 - Cryptosporidium in Wastewater Occurrence, Removal 

and Inactivation

Water Environment 

Research Foundation

98-PUM-1CO - 

A Comparative study of Physiochemical Properties and 

Filtration of Several Human and Bacteria Viruses: 

Implication for Groundwater Recharge

Water Environment 

Research Foundation

99-HHE-1 - Effects of Wastewater Disinfection on Human Health Water Environment 

Research Foundation

99-HHE-4ET - Handheld Advanced Nucleic Acid Analyzer (HANNA) 

for Waterborne Pathogen Detection

Water Environment 

Research Foundation

99-HHE-5-UR - Development of Molecular Methods for Detection of 

Infectious Viruses in Treated Wastewater

Water Environment 

Research Foundation

99-PUM-4 - Impact of Surface Storage on Reclaimed Water: 

Seasonal and Long Term

Water Environment 

Research Foundation

99-WWF-6 - Online Monitoring of Water Effluent Chlorination Using 

ORP vs. Residual Chlorine Measurement

Water Environment 

Research Foundation

00-CTS-8 - Membrane Technology: Feasibility of Solid/Liquid 

Separation in Wastewater Treatment

Water Environment 

Research Foundation

00-CTS-11 - Membrane Technology: Pilot Studies of MembraneAerated Bioreactors

Water Environment 

Research Foundation

00-CTS- 14-ET - A Novel Membrane Process for Autotrophic 

Denitrification

Water Environment 

Research Foundation

00-HHE-2A - Overcoming Molecular Sample Processing Limitations: 

New Platform Technologies

Water Environment 

Research Foundation

00-HHE-2C - Overcoming Molecular Sample Processing Limitations: 

Quantitative PCR

Water Environment 

Research Foundation

00-HHE-7-CO - Endocrine Disruptors and Pharmaceutically Active 

Chemicals in Drinking Water

Water Environment 

Research Foundation

00-HHE-2C - Overcoming Molecular Sample Processing Limitations: 

Fiber Optic Biosensors

Water Environment 

Research Foundation

00-PUM-1 - Water Reuse: Understanding Public Perception and 

Participation

Water Environment 

Research Foundation

OO-PUM-2T - 

Reduction of Pathogens, Indicator Bacteria, and 

Alternative Indicators by Wastewater Treatment and 

Reclamation Processes

Water Environment 

Research Foundation

00-PUM-3 - Evaluation of Microbial Risk Assessment Techniques 

and Applications

Water Environment 

Research Foundation

00-WSM-6 - Strategies for Sustainable Water Resource 

Management

Water Environment 

Research Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

B-4 2012 Guidelines for Water Reuse

Project 

Number Publication Date Title Organization

00-WSM-6A - 

Moving Towards Sustainable Water Resources 

Management: A Framework and Guidelines for 

Implementation

Water Environment 

Research Foundation

01-CTS-6 and

01-CTS-6A - Membrane Treatment of Secondary Wastewater Effluent for Subsequent Use

Water Environment 

Research Foundation

01-CTS-19-UR - Effects of Biosolids Properties on Membrane 

Bioreactors and Solids Processing

Water Environment 

Research Foundation

01-CTS-31-ET - Dynamic Medialess Microfiltration for Membrane 

Prefiltration

Water Environment 

Research Foundation

01-HHE-1 - Applications of DNA Microarray Technology for 

Wastewater Analysis

Water Environment 

Research Foundation

01-HHE-2A - Molecular Alternatives to Indicator and Pathogen 

Detection: Real-Time PCR

Water Environment 

Research Foundation

01-HHE-4A - Online Methods of Evaluating the Safety of Reclaimed 

Water

Water Environment 

Research Foundation

02-CTS-4 & 02-

CTS-4A - Membrane Bioreactors for Anaerobic Treatment of 

Wastewaters

Water Environment 

Research Foundation

03-CTS-17cCO - Impacts of Membrane Process Residuals on 

Wastewater Treatment

Water Environment 

Research Foundation

03-CTS-18C0 - Long-Term Effects of Landscape Irrigation Using 

Household Graywater

Water Environment 

Research Foundation

03-CTS-22-UR - Fate of Pharmaceuticals and Personal Care Products 

through Wastewater Treatment Processes

Water Environment 

Research Foundation

04-SW-1 - Using Rainwater to Grow Livable Communities Water Environment 

Research Foundation

04-HHE-3 - Microbial Risk Assessment Interface Tool and User 

Documentation Guide

Water Environment 

Research Foundation

06-CTS-1C0 - Long-Term Study on Landscape Irrigation using 

Household Graywater- Experimental Study (Phase 2)

Water Environment 

Research Foundation

DEC3R06 - When to Consider Distributed Systems in an Urban and 

Suburban Context

Water Environment 

Research Foundation

- 2007 Dewatering Reverse Osmosis Concentrate from Water 

Reuse Applications Using Forward Osmosis WateReuse Foundation

- 2009 How to Develop a Water Reuse Program : Manual of 

Practice WateReuse Foundation

- 2010 Reaction Rates and Mechanisms of Advanced 

Oxidation Processes (AOP) for Water Reuse WateReuse Foundation

- 2005 Irrigation of Parks, Playgrounds, and Schoolyards with 

Reclaimed Water: Extent and Safety WateReuse Foundation

- 2006

Rejection of Wastewater-Derived Micropollutants in 

High-Pressure Membrane Applications Leading to 

Indirect Potable Reuse: Effects of Membrane and 

Micropollutant Properties

WateReuse Foundation

- 2009 The Psychology of Water Reclamation and Reuse : 

Survey Findings and Research Roadmap WateReuse Foundation

- 2006 Marketing Nonpotable Recycled Water WateReuse Foundation

- 2004 Water Reuse Economic Framework Workshop Report WateReuse Foundation

- 2011

Talking About Water : Vocabulary and Images That 

Support Informed Decisions About Water Recycling 

and Desalination 

WateReuse Foundation

- 2006 An Economic Framework for Evaluating the Benefits 

and Costs of Water Reuse WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

2012 Guidelines for Water Reuse B-5 

Project 

Number Publication Date Title Organization

- 2004 Best Practices for Developing Indirect Potable Reuse 

Projects: Phase 1 Report WateReuse Foundation

- 2008 The Impacts of Membrane Process Residuals on 

Wastewater Treatment Guidance Manual WateReuse Foundation

- 2011

Optimization of Advanced Oxidation Processes for 

Water Reuse : Effect of Effluent Organic Matter on 

Organic Contaminant Removal

WateReuse Foundation

- 2010 Low-Cost Treatment Technologies for Small-Scale 

Water Reclamation Plants WateReuse Foundation

- 2011 Direct Potable Reuse : A Path Forward WateReuse Foundation

- 2010 Oxidative Treatment of Organics in Membrane 

Concentrates WateReuse Foundation

WRF-01-001 Dec-05 Alternative Methods for the Analysis of NDMA and 

Other Nitrosamines in Water and Wastewater WateReuse Foundation

WRF-01-002 May-06 Removal and/or Destruction of NDMA in Wastewater 

Treatment Processes WateReuse Foundation

WRF-01-004 Jun-05 Best Practices for Developing Indirect Potable Reuse 

Projects: Phase 1 Report WateReuse Foundation

WRF-01-005 May-06 Characterizing and Managing Salinity Loadings in 

Reclaimed Water Systems (AWWARF 91009) WateReuse Foundation

WRF-01-006 May-06 Characterizing Microbial Water Quality in Reclaimed 

Water Distribution Systems (AWWARF 91072F) WateReuse Foundation

WRF-01-007 2006 Removal of Endocrine Disrupting Compounds in Water 

Reclamation Processes (WERF 01HHE20T) WateReuse Foundation

WRF-01-008 2007

Innovative DNA Array Technology for Detection of 

Pharmaceutics in Reclaimed Water (WERF 

01HHE21T)

WateReuse Foundation

WRF-02-001 May-06 Rejection of Wastewater-Derived Micropollutants in 

High-Pressure Membrane Applications WateReuse Foundation

WRF-02-002 Jun-06 Investigation of NDMA Fate and Transport WateReuse Foundation

WRF-02-003 Aug-11 Filter Loading Evaluation for Water Reuse WateReuse Foundation

WRF-02-004 Nov-08 National Database on Water Reuse Facilities - 

Summary Report WateReuse Foundation

WRF-02-006a Aug-08 Survey of High Recovery and Zero Liquid Discharge 

Technologies for Water Utilities WateReuse Foundation

WRF-02-006b Sep-06 Beneficial and Non-Traditional Uses of Concentrate WateReuse Foundation

WRF-02-006c Jul-08 The Impacts of Membrane Process Residuals on 

Wastewater Treatment WateReuse Foundation

WRF-02-006d Aug-08 Regional Solutions for Concentrate Management WateReuse Foundation

WRF-02-007 2003 Using Surfactants in Optimizing Water Usage on Turf 

Grasses WateReuse Foundation

WRF-02-008 Mar-09 A Reconnaissance-Level Quantitative Comparison of 

Reclaimed Water, Surface Water, and Groundwater WateReuse Foundation

WRF-02-009 Aug-12 Study of Innovative Treatment on Reclaimed Water WateReuse Foundation

WRF-02-011 2005

Framework for Developing Water Reuse Criteria with 

Reference to Drinking Water Supplies (UKWIR 

05/WR/29/1)

WateReuse Foundation

WRF-03-001 2007 Pathogen Removal and Inactivation in Reclamation 

Plants - Study Design WateReuse Foundation

WRF-03-005 Sep-06 Marketing Nonpotable Recycled Water: A Guidebook 

for Successful Public Outreach & Customer Marketing WateReuse Foundation

WRF-03-006-01 2004 Water Reuse Economic Framework Workshop Report WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

B-6 2012 Guidelines for Water Reuse

Project 

Number Publication Date Title Organization

WRF-03-006-02 Sep-06 An Economic Framework for Evaluating Benefits and 

Costs of Water Reuse WateReuse Foundation

WRF-03-009 Aug-07 Reclaimed Water Aquifer Storage and Recovery: 

Potential Changes in Water Quality WateReuse Foundation

WRF-03-010 2004 Water Reuse Foundation's Water Reuse Research 

Needs Workshop WateReuse Foundation

WRF-03-011 2004

Research Needs Assessment Workshop on Integrating 

Human Reactions to Water Reclamation into Reuse 

Project Design

WateReuse Foundation

WRF-03-012 Aug-08 Salt Management Guide WateReuse Foundation

WRF-03-013 2008

Rejection of Contaminants of Concern by NF and 

ULPRO Membranes for Treating Water of Impaired 

Quality

WateReuse Foundation

WRF-03-014 Dec-08

Development of Indicators and Surrogates of Chemical 

Contaminants and Organic Removal in Wastewater 

and Water Reuse

WateReuse Foundation

WRF-04-001 2008 Prospects for Managed Underground Storage of 

Recoverable Water WateReuse Foundation

WRF-04-002 May-06 Effects of Recycled Water on Turfgrass Quality 

Maintained Under Golf Course Fairway Conditions WateReuse Foundation

WRF-04-003 2008 Toxicological Relevance of Endocrine Disruptors & 

Pharmaceuticals in Drinking Water (AWWARF 91238) WateReuse Foundation

WRF-04-004 Jan-09 Honolulu Membrane Bioreactor Pilot Study WateReuse Foundation

WRF-04-005 Mar-12 Use of Recycled Water for Community Gardens WateReuse Foundation

WRF-04-006 2005 Irrigation of Parks, Playgrounds, and Schoolyards with 

Reclaimed Water: Extent and Safety WateReuse Foundation

WRF-04-007 2005 GWRC Water Reuse Research Strategy WateReuse Foundation

WRF-04-008 Dec-09 The Psychology of Water Reclamation and Reuse: 

Survey Findings and Research Roadmap WateReuse Foundation

WRF-04-009 Aug-12 Reclaimed Water Inspection and Cross Connection 

Control Guidebook WateReuse Foundation

WRF-04-010 Nov-07 Extending the IRP Process to Include Water Reuse and 

Other Non-Traditional Water Sources WateReuse Foundation

WRF-04-011 Nov-07 Application of Microbial Risk Assessment Techniques 

to Estimate Risk Due to Exposure to Reclaimed Waters WateReuse Foundation

WRF-04-012 Aug-09

Exploring, Interpreting, and Presenting Microbial Data 

Associated with Reclaimed Water Systems: A 

Guidance Manual

WateReuse Foundation

WRF-04-013 Aug-10 Improved Sample Collection and Concentration Method 

for Multiple Pathogen Detection WateReuse Foundation

WRF-04-014 Apr-09 Decision Support System for Selection of Satellite vs. 

Regional Treatment for Reuse WateReuse Foundation

WRF-04-016 Jun-09 A Protocol for Estimating Potential Water Quality 

Impacts of Recycled Water Projects WateReuse Foundation

WRF-04-017 Mar-10 Reaction Rates and Mechanisms of Advanced 

Oxidation Processes (AOP) for Water Reuse WateReuse Foundation

WRF-04-018 2009

Contributions of Household Chemicals to Sewage and 

Relevance to Municipal Wastewater Systems and the 

Environment (WERF 03CTS21UR)

WateReuse Foundation

WRF-04-019 Apr-09

Methods for the Detection of Residual Concentrations 

of Hydrogen Peroxide in Advanced Oxidation 

Processes

WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

2012 Guidelines for Water Reuse B-7 

Project 

Number Publication Date Title Organization

WRF-04-021 Dec-09 Selecting Treatment Trains for Seasonal Storage of 

Reclaimed Water WateReuse Foundation

WRF-05-001 Nov-09 Evaluating Pricing Levels and Structures to Support 

Reclaimed Water Systems WateReuse Foundation

WRF-05-002 Jan-10 Microbiological Quality/Biostability of Reclaimed Water 

Following Storage and Distribution WateReuse Foundation

WRF-05-004 Nov-11

Development of Surrogates to Determine the Efficacy 

of Soil Aquifer Treatment Systems for the Removal of 

Organic Chemicals

WateReuse Foundation

WRF-05-005 Aug-10

Identification of PPCPs for Screening Based on 

Persistence through Treatments used for Indirect 

Potable Reuse and Toxicity

WateReuse Foundation

WRF-05-006 Jan-11 Evaluate Wetland Systems for Treated Wastewater 

Performance to Meet Competing Effluent Quality Goals WateReuse Foundation

WRF-05-007 Jun-09

Selection and Testing of Tracers for Measuring Travel 

Times in Groundwater Aquifers Augmented with 

Reclaimed Water

WateReuse Foundation

WRF-05-008 Sep-09 The Effect of Salinity on the Removal of Contaminants 

of Concern during Biological Water Reclamation WateReuse Foundation

WRF-05-009 Aug-07 Dewatering Reverse Osmosis Concentrate from Water 

Reuse Applications Using Forward Osmosis WateReuse Foundation

WRF-05-010 May-10 Oxidative Destruction of Organics in Membrane 

Concentrates WateReuse Foundation

WRF-05-011 Aug-09 Formation and Fate of Chlorination Byproducts in 

Desalination Systems WateReuse Foundation

WRF-06-001 Nov-08 Conduct Survey Research to Obtain Information/Data 

from all Water Recycling Facilities in CA WateReuse Foundation

WRF-06-002 Jan-09 Developing a Pragmatic Research Agenda for 

Examining the Value of Water Supply Reliability WateReuse Foundation

WRF-06-003 Expected Oct-12 The Occurrence of Infectious Cryptosporidium Oocysts 

in Raw, Treated and Disinfected Wastewater WateReuse Foundation

WRF-06-004 Aug-12

Identifying Health Effects Concerns of the Water Reuse 

Industry and Prioritizing Research Needs for 

Nomination of Chemicals for Research

WateReuse Foundation

WRF-06-005 Dec-09

Leaching of Metals from Aquifer Soils during Infiltration 

of Low-Ionic-Strength Reclaimed Water: Determination 

of Kinetics and Potential Mitigation Strategies

WateReuse Foundation

WRF-06-006 Expected Mar-13 Comparisons of Chemical Composition of Recycled 

and Conventional Waters WateReuse Foundation

WRF-06-007 Mar-12 Investigation of Membrane Bioreactor Effluent Water 

Quality and Technology WateReuse Foundation

WRF-06-008 Jul-10 Low-Cost Treatment Technologies for Small-Scale 

Water Reclamation Plants WateReuse Foundation

WRF-06-009 Expected Jan-13 Predictive Models to Aid in Design of Membrane 

Systems for Organic Micropollutants Removal WateReuse Foundation

WRF-06-010a Expected Oct-12 State of the Science Review of Membrane Fouling: 

Organic, Inorganic, and Biological WateReuse Foundation

WRF-06-010b Expected Sep-12 Feasibility Study of Offshore Desalination Plants WateReuse Foundation

WRF-06-010d Expected Dec-12 Consideration for the Co-Siting of Desalination 

Facilities with Municipal and Industrial Facilities WateReuse Foundation

WRF-06-010e Expected Jan-13 Development of Selective Recovery Methods for 

Desalination Concentrate Salts WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

B-8 2012 Guidelines for Water Reuse

Project 

Number Publication Date Title Organization

WRF-06-010f 2010 Post Treatment Stabilization of Desalinated Water 

(WaterRF 4079) WateReuse Foundation

WRF-06-010g 2011 Assessing Seawater Intake Systems for Desalination 

Plants (WaterRF 4080) WateReuse Foundation

WRF-06-011 Expected Jan-13 Enhanced Disinfection of Adenoviruses with UV 

Irradiation WateReuse Foundation

WRF-06-012 May-11 Optimization of Advanced Oxidation Processes (AOP) 

for Water Reuse WateReuse Foundation

WRF-06-013 Expected Oct-12 Investigating the Feasibility of MBR to Achieve Low 

Nitrogen Levels for Water Reuse WateReuse Foundation

WRF-06-014 Dec-11

Characterization of US Seawaters & Development of 

Standardized Protocols for Evaluation of Foulants in 

Seawater RO Desalination

WateReuse Foundation

WRF-06-015 Dec-10 Sequential UV and Chlorination for Reclaimed Water 

Disinfection WateReuse Foundation

WRF-06-016 Jul-11 Guidance on Links between Water Reclamation and 

Reuse and Regional Growth WateReuse Foundation

WRF-06-017 May-12 Water Reuse in 2030: Identifying Future Challenges 

and Opportunities WateReuse Foundation

WRF-06-018 Apr-11

Development and Application of Tools to Assess and 

Understand the Relative Risks of Regulated Chemicals 

in Indirect Potable Reuse Projects - Tasks 1-3 

WateReuse Foundation

WRF-06-018 Nov-10

Tool to Assess and Understand the Relative Risks of 

drugs and Other Chemicals in Indirect Potable Reuse 

Water: Development and Application

WateReuse Foundation

WRF-06-018 Expected Oct-12

Tool to Assess and Understand the Relative Risks of 

drugs and Other Chemicals in Indirect Potable Reuse 

Water: Executive Summary

WateReuse Foundation

WRF-06-019 May-10

Monitoring for Microcontaminants in an Advanced 

Wastewater Treatment Facility and Modeling Discharge 

of Reclaimed Water to Surface Canals for Indirect 

Potable Use

WateReuse Foundation

WRF-06-020 Sep-11 Attenuation of Emerging Contaminants in Streams 

Augmented with Recycled Water WateReuse Foundation

WRF-06-021 Jun-12 Interagency Partnerships to Facilitate Water Reuse WateReuse Foundation

WRF-07-01 Expected Nov-12 Validation of Microbiological Methods for Use with 

Reclaimed Waters WateReuse Foundation

WRF-07-02 Expected Oct-12 Development of a Knowledge Base on Concentrate 

and Salt Management Practices WateReuse Foundation

WRF-07-03 Jul-11

Talking About Water: Vocabulary and Images that 

Support Informed Decisions about Water Recycling and 

Desalination

WateReuse Foundation

WRF-07-04 Expected Oct-12 Evaluation of Impact of Nanoparticle Pollutants WateReuse Foundation

WRF-07-05 Expected Oct-12 Membrane Distillation using Nanostructured 

Membranes WateReuse Foundation

WRF-07-06 Expected Oct-12 Recycled Water Use in Zoo/Wildlife Facility Settings WateReuse Foundation

WRF-08-01 Nov-10 Assessment of Approaches to Achieve Nationally 

Consistent Reclaimed Water Standards WateReuse Foundation

WRF-08-02 Dec-12 Attenuation of PPCP/EDCs through Golf Courses using 

Reuse Water (WERF1C08) WateReuse Foundation

WRF-08-04 Expected Jan-13 Approaches to Maintain Consistently High Quality 

Reclaimed Water in Storage and Distribution Systems WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

2012 Guidelines for Water Reuse B-9 

Project 

Number Publication Date Title Organization

WRF-08-05 Expected Feb-13 Use of Ozone in Water Reclamation for Contaminant 

Oxidation WateReuse Foundation

WRF-08-06 Expected Jan-13 Evaluation of Alternatives to Domestic Ion Exchange 

Water Softeners WateReuse Foundation

WRF-08-07 Expected Nov-12 Disinfection Guidelines for Satellite Water Recycling 

Facilities WateReuse Foundation

WRF-08-08 Expected Apr-13 Pilot-Scale Oxidative Technologies for Reducing 

Fouling Potential in Membrane Systems WateReuse Foundation

WRF-08-09 Expected Oct-12 Value of Water Supply Reliability in Residential Sector WateReuse Foundation

WRF-08-10 Dec-11 Maximizing Recovery of Recycled Water for 

Groundwater Recharge WateReuse Foundation

WRF-08-11 Expected Jul-13 Process Optimization, Monitoring and Control 

Strategies, and Carbon and Energy Footprint UV/H2O2 WateReuse Foundation

WRF-08-12 Expected Dec-12 Assess water use requirements and establish water 

quality criteria WateReuse Foundation

WRF-08-13 Expected Oct-12 Renewable energy, peak power management, and 

optimization of advanced treatment technologies WateReuse Foundation

WRF-08-14 Expected Oct-12 Evaluation and optimization of existing and emerging 

energy recovery devices WateReuse Foundation

WRF-08-15 Expected Sep-12 Evaluating Emergency Planning under Climate Change 

Scenarios WateReuse Foundation

WRF-08-16 Aug-12 Implications of Future Water Supply Sources on Energy 

Demands WateReuse Foundation

WRF-08-17 Feb-12 Reclaimed Water Desalination Technologies: 

Performance/Cost Comparison EDR & MF/RO WateReuse Foundation

WRF-08-18 Mar-12 Infectivity Assay for Giardia lamblia Cysts WateReuse Foundation

WRF-08-19 Expected Mar-13 Investigation of Desalination Membrane Biofouling WateReuse Foundation

WRF-09-01 Expected Dec-12 The Effect of Prior Knowledge of ‘Unplanned’ Potable 

Reuse on Acceptance of ‘Planned’ Potable Reuse WateReuse Foundation

WRF-09-02 Expected Jun-13 Develop a Framework to Determine When to Use 

Indirect Potable Reuse Systems vs. Dual Pipe WateReuse Foundation

WRF-09-03 Expected Apr-13 Utilization of HACCP Approach for Evaluating Integrity 

of Treatment Barriers for Reuse WateReuse Foundation

WRF-09-04 Expected Apr-13 The Value of Water Supply Reliability in the CII Sector WateReuse Foundation

WRF-09-05 Expected Sept-12 Case Studies of Seasonal Storage of Reclaimed Water 

for Discharge into Surface Waters WateReuse Foundation

WRF-09-06a Expected Mar-13 Develop New Techniques for Real-Time Monitoring of 

Membrane Integrity WateReuse Foundation

WRF-09-06b Expected Mar-13 Develop New Techniques for Real-Time Monitoring of 

Membrane Integrity WateReuse Foundation

WRF-09-07 May-12 Risk Assessment Study of PPCPs in Recycled Water to 

Support Public Review - Toolkit WateReuse Foundation

WRF-09-07 Expected Oct-12 Risk Assessment Study of PPCPs in Recycled Water to 

Support Public Review - Main Report WateReuse Foundation

WRF-09-08 Expected Feb-13 Evaluation of Potential Nutrient Impacts Related to 

Florida's Water Reuse Program WateReuse Foundation

WRF-09-09 Expected Sep-12 Pilot Testing Pre-Formed Chloramines as a Means of 

Controlling Biofouling in Seawater Desalination WateReuse Foundation

WRF-09-10 Feb-13

Use of UV & Fluorescence Spectra as Surrogate 

Measures for Contaminant Oxidation and Disinfection 

in Ozone/Peroxide Advanced Oxidation Processes

WateReuse Foundation

WRF-09-11 Expected Feb-14 Development of New Tracers for Determining Travel 

Time Near MAR Operations WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

B-10 2012 Guidelines for Water Reuse

Project 

Number Publication Date Title Organization

WRF-09-12 Expected Nov-12 Continuous Flow Seawater RO System for Recovery of 

Silica Saturated RO Concentrate WateReuse Foundation

WateReuse-10-

01 Expected May-14 Fit for Purpose Water: The Cost of "Over-Treating" 

Reclaimed and other Water WateReuse Foundation

WateReuse-10-

02 Expected Mar-13 Treatment, Public Health, and Regulatory Issues Associated with Graywater Reuse WateReuse Foundation

WateReuse-10-

03 Expected Jun-13 Regulatory Workshop on Critical Issues of Desalination Permitting WateReuse Foundation

WateReuse-10-

04 Expected Jul- 2013 Improvements to Minimize I&E of Existing Intakes WateReuse Foundation

WateReuse-10-

05 Expected Nov-14 Role of Retention Time in the Environmental Buffer of Indirect Potable Reuse Projects WateReuse Foundation

WateReuse-10-

06a Aug-13 Lower Energy Treatment Schemes for Water Reuse, Part A WateReuse Foundation

WateReuse-10-

06b Expected Aug-13 Lower Energy Treatment Schemes for Water Reuse, 

Part B WateReuse Foundation

WateReuse-10-

06c Expected May-13 Lower Energy Treatment Schemes for Water Reuse, Part C WateReuse Foundation

WateReuse-10-

06d Expected Aug-13 Lower Energy Treatment Schemes for Water Reuse, Part D WateReuse Foundation

WateReuse10-

06 II TBD Lower Energy Treatment Schemes for Water Reuse - 

Phase II WateReuse Foundation

WateReuse-10-

07 Expected May-14 Bio-analytical Techniques to Assess the Potential 

Human Health Impacts of Reclaimed Water WateReuse Foundation

WateReuse-10-

08 Expected Feb-13 Guidance for Implementing Reuse in New Buildings & Developments to Achieve LEED/Sustainability Goals WateReuse Foundation

WateReuse-10-

09 Expected Apr-13 Guidance for Selection of Salt, Metal, Radionuclide, 

and other Valuable Metal Recovery Strategies WateReuse Foundation

WateReuse-10-

10 Expected Nov-12 Demonstration of Filtration and Disinfection 

Compliance through SAT WateReuse Foundation

WateReuse-10-

11 Expected Jul-13 Ozone Pretreatment of Non-Nitrified Secondary Effluent before Microfiltration WateReuse Foundation

WateReuse-10-

12 Expected May-13

Feasibility Study on Model Development to 

Estimate/Minimize GHG Concentrations and Carbon 

Footprint of WateReuse and Desalination Facilities

WateReuse Foundation

WateReuse-10-

13 Expected Nov-12 Review of Nano-Material Research and Relevance for Water Reuse WateReuse Foundation

WateReuse-10-

14 Expected Nov-12

Future of Purple Pipes: Exploring best use of nonpotable recycled water in diversified urban water 

systems

WateReuse Foundation

WateReuse-10-

15 Expected Oct-13 Establishing Nitrification Reliability Guidelines for Water Reuse WateReuse Foundation

WateReuse-10-

16 Expected Oct-13 Enzymes: The New Wastewater Treatment Chemical for Water Reuse WateReuse Foundation

WateReuse-10-

17 Expected Jul-13

Understanding the Influence of Stakeholder Groups on 

the Effectiveness of Urban Recycled Water Program 

Implementation

WateReuse Foundation

WateReuse-10-

18 Expected Dec-13 Regulated and Emerging Disinfection by-Products during the Production of High Quality Recycled Water WateReuse Foundation

WateReuse-11-

01 Expected Mar-16 Monitoring for Reliability and Process Control of 

Potable Reuse Applications WateReuse Foundation

WateReuse-11-

02 Expected Jul-15 Equivalency of Advanced Treatment Trains for Potable 

Reuse WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

2012 Guidelines for Water Reuse B-11

Project 

Number Publication Date Title Organization

WateReuse-11-

03 Expected Sep-14

Develop Best Management Practices to Control 

Potential Health Risks and Aesthetic Issues Associated 

with Storage/Distribution of Reclaimed Water

WateReuse Foundation

WateReuse-11-

04 Expected Mar-15 Emerging Desalination Technologies for Energy Reduction WateReuse Foundation

WateReuse-11-

05 Expected May-14 Demonstrating the Benefits of Engineered Direct versus Unintended Indirect Potable Reuse Systems WateReuse Foundation

WateReuse-11-

06 Expected Oct-13 Real Time Monitoring for Microbiological Contaminants 

in Reclaimed Water: State of the Science Assessment WateReuse Foundation

WateReuse-11-

07 Expected Jan-15

Application of the Bioluminescent Saltwater Assimilable 

Organic Carbon Test as a Tool for Identifying and 

Reducing Reverse-Osmosis Membrane Fouling in 

Desalination

WateReuse Foundation

WateReuse-11-

08 Expected Oct-14 Formation of Nitrosamines and Perfluorochemicals 

during Ozonation in Water Reuse Applications WateReuse Foundation

WateReuse-11-

09 Expected Jan-14 Desalination Concentrate Management Policy Analysis for the Arid West WateReuse Foundation

WateReuse-11-

10 Expected Dec-13 Evaluation of Risk Reduction Principles for Direct Potable Reuse WateReuse Foundation

WateReuse-12-

01 TBD Desalination Facility Guidelines (Scoping Study) WateReuse Foundation

WateReuse-12-

02 TBD Development of Public Communication Toolbox for Desalination Projects WateReuse Foundation

WateReuse-12-

03 TBD

Analysis of Technical and Organizational Issues in the 

Development and Implementation of Industrial Reuse 

Projects 

WateReuse Foundation

WateReuse-12-

05 TBD Management of Legionella in Water Reclamation 

Systems WateReuse Foundation

WateReuse-12-

06 TBD Guidelines for Engineered Storage Systems WateReuse Foundation

WateReuse-12-

07 TBD Standard Methods for Integrity Testing of NF and RO 

Membranes WateReuse Foundation

WateReuse-12-

08 TBD Public Acceptance Clearinghouse of Information for 

Website WateReuse Foundation

WateReuse-12-

10 Expected Sept-13

Demonstrating an Innovative Combination of Ion 

Exchange Pretreatment and Electrodialysis Reversal 

for Reclaimed Water RQ Concentrate Minimization

WateReuse Foundation
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports

B-12 2012 Guidelines for Water Reuse

This page intentionally left blank.
2012 Guidelines for Water Reuse C-1 

APPENDIX C 

Websites of U.S. State Regulations and 

Guidance on Water Reuse 

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 

https://www.watereuse.org/government-affairs/usepa-guidelines. 

State Title of Regulations or Guidelines

Link to State Reuse Regulations 

or Guidance

Alternate Link to Reuse 

Fact Sheet or Report

Alabama

Guidelines and Minimum Requirement 

for Municipal, Semi-Public and Private 

Land Treatment Facilities

http://adem.alabama.gov/alEnviroRe

gLaws/default.cnt

Alaska

Alaska Administrative Code, Title 18 – 

Environmental Conservation, Chapter 

72 - Wastewater Disposal

http://dec.alaska.gov/commish/regul

ations/pdfs/18%20AAC%2072.pdf

Alaska - 

additional 

http://dec.alaska.gov/water/wwdp/in

dex.htm

Arizona Arizona Administrative Code - Title 18, 

Environmental Quality

http://www.azsos.gov/public_service

s/Title_18/18_table.htm

http://www.azdeq.gov/en

viron/water/permits/reclai

med.html 

Arkansas 

40 CFR 257, 40 CFR 503, and 

guidance from NRCS (for animal 

wastes)

http://www.adeq.state.ar.us/water/re

gulations.htm

California Title 22 California Code of Regulations http://www.cdph.ca.gov/certlic/drinki

ngwater/Pages/Lawbook.aspx

http://www.waterboards.c

a.gov/water_issues/progr

ams/grants_loans/water_

recycling/directory.shtml 

California - 

additional

http://www.cdph.ca.gov/HealthInfo/e

nvironhealth/water/Pages/Waterrecy

cling.aspx

Colorado

Water Quality Control Commission: 

Regulation No. 84 - Reclaimed Water 

Control Regulation (effective 9/30/07)

http://www.cdphe.state.co.us/regulat

ions/wqccregs/ 

Colorado - 

additional

http://www.cdphe.state.co.us/regulat

ions/wqccregs/100284wqccreclaime

dwater.pdf

Commonwealth 

of the Northern 

Mariana Islands

Commonwealth of the Northern 

Mariana Islands Wastewater 

Treatment and Disposal Rules and 

Regulations

http://www.deq.gov.mp/artdoc/Sec6

art32ID130.pdf

Connecticut No regulations or guidelines at this 

time

http://www.ct.gov/dep/cwp/view.asp

?a=2709&q=324216&depNav_GID=

1643

Delaware

http://www.dnrec.delaware.gov/wr/In

formation/regulations/Pages/Ground

WaterDischargesRegulations.aspx

Delaware - 

additional

http://www.dnrec.state.de.us/water2

000/Sections/GroundWat/Library/Re

claimedWaterFactSheet.pdf 
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse

C-2 2012 Guidelines for Water Reuse

State Title of Regulations or Guidelines

Link to State Reuse Regulations 

or Guidance

Alternate Link to Reuse 

Fact Sheet or Report

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.

Florida

Chapter 62-610 of the Florida 

Administrative Code "Reuse of 

Reclaimed Water and Land 

Application; Section 403.064 of the 

Florida Statutes

http://www.dep.state.fl.us/water/reus

e/apprules.htm 

Georgia

Guidelines for Water Reclamation and 

Urban Water Reuse; Georgia 

Guidelines for Reclaimed Water 

Systems for Buildings; Constructed 

Wetlands Municipal Wastewater 

Treatment Facilities Guidelines; 

Guidelines for Slow-Rate Land 

Treatment of Wastewater Via Spray 

Irrigation (LAS Guidelines)

http://www.gaepd.org/Files_PDF/tec

hguide/wpb/reuse.pdf 

Georgia - 

additional

http://www.gaepd.org/Documents/te

chguide_wpb.html

Guam

http://epa.guam.gov/rulesregs/regulations/water-pollutionregulations/

Hawaii Guidelines for the Treatment and Use 

of Recycled Water

http://hawaii.gov/wastewater/pdf/reu

se-final.pdf 

Hawaii - 

additional

http://hawaii.gov/dlnr/cwrm/planning

_augmentation.htm 

Idaho

Idaho Administrative Code, Tittle 01, 

Chapter 17, IDAPA 58.01.17 - 

Recycled Water Rules 

http://adminrules.idaho.gov/rules/cur

rent/58/0117.pdf 

Idaho - 

additional

http://adminrules.idaho.gov/rules/cur

rent/58/index.html

Illinois

Title 35 Illinois Administrative Code 

Part 372 - Illinois Design Standards for 

Slow Rate Land Application of Treated 

Wastewater

http://www.ipcb.state.il.us/document

s/dsweb/Get/Document-12046/

http://www.ilga.gov/legisl

ation/ilcs/fulltext.asp?Doc

Name=007023050K7

Indiana

Article 6.1 "Land application of 

Biosolid, Industrial Waste Product, and 

Pollutant-bearing Water" of Title 327 

Water Pollution Control Board, Indiana 

Administrative Code.

http://www.in.gov/idem/4877.htm http://www.in.gov/legislati

ve/iac/title327.html 

Iowa

Iowa Administrative Code Chapter 62: 

Effluent and Pretreament Standards: 

Other Effluent Limits or Prohibitinos

http://www.iowadnr.gov/InsideDNR/

RegulatoryWater/NPDESWastewate

rPermitting/NPDESRules.aspx

http://www.iowadnr.gov/p

ortals/idnr/uploads/water/

wastewater/dstandards/c

hapter21.pdf?amp;tabid=

1316

Kansas http://www.kdheks.gov/water/downlo

ad/28_16.pdf

http://www.kwo.org/Kans

as_Water_Plan/KWP_Do

cs/VolumeIII/LARK/Rpt_L

ARK_BPI_Role_Reuse_

KWP2009.pdf 
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse

2012 Guidelines for Water Reuse C-3 

State Title of Regulations or Guidelines

Link to State Reuse Regulations 

or Guidance

Alternate Link to Reuse 

Fact Sheet or Report

Kentucky No regulations or guidelines at this 

time

Web Address could not be located 

at time of publication.

Louisiana No regulations or guidelines at this 

time

Web Address could not be located 

at time of publication.

Maine No regulations or guidelines at this 

time

Web Address could not be located 

at time of publication.

Maryland

Environment Article, Title 9, Subtitle 3; 

COMAR 26.08.01through 26.08.04 

and 26.08.07.

http://www.mde.state.md.us/assets/

document/MDE-WMA001%20%28landtreatment%20Guidelines%29.pdf

http://www.mde.state.md.

us/programs/Permits/Wat

erManagementPermits/D

ocuments/www.mde.stat

e.md.us/assets/document

/permit/MDE-WMAPER014.pdf 

Maryland - 

additional

http://www.mde.state.md.us/progra

ms/Permits/WaterManagementPerm

its/WaterDischargePermitApplication

s/Pages/Permits/WaterManagement

Permits/water_permits/index.aspx 

Massachusetts http://www.mass.gov/dep/service/re

gulations/314cmr20.pdf

http://www.mass.gov/dep

/water/wastewater/wrfaqs

.htm#permit 

Massachusetts - 

additional

http://www.mass.gov/dep/service/re

gulations/314cmr05.pdf 

Michigan Web Address could not be located 

at time of publication.

Minnesota http://www.pca.state.mn.us/index.ph

p/view-document.html?gid=13496

Mississippi

http://www.deq.state.ms.us/newweb/

MDEQRegulations.nsf?OpenDataba

se

Missouri http://www.sos.mo.gov/adrules/csr/c

urrent/10csr/10csr.asp#10-20 

http://www.dnr.mo.gov/en

v/wpp/permits/index.html

Montana http://deq.mt.gov/wqinfo/pws/docs/d

eq2 revisions.pdf

Nebraska

Title 119, Chapter 12 - Land 

Application of Domestic Effluent, Land 

Application of Single Pass Noncontact 

Cooling Water and Disposal of 

Domestic Biosolids

http://www.deq.state.ne.us/RuleAnd

R.nsf/pages/119-Ch-12

http://www.deq.state.ne.u

s/RuleandR.nsf/Pages/R

ules

Nebraska - 

additional

http://www.deq.state.ne.us/RuleAnd

R.nsf/23e5e39594c064ee852564ae

004fa010/97c32c5cd6c1802d86256

74b006da528?OpenDocument

Nebraska - 

additional

http://www.deq.state.ne.us/RuleAnd

R.nsf/23e5e39594c064ee852564ae

004fa010/235cf139930e82d086256

74b006e0738?OpenDocument

Nebraska - 

additional

http://www.deq.state.ne.us/RuleAnd

R.nsf/23e5e39594c064ee852564ae

004fa010/6fc9b4ab05f90c8e862567

4b006fa9ab?OpenDocument
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse

C-4 2012 Guidelines for Water Reuse

State Title of Regulations or Guidelines

Link to State Reuse Regulations 

or Guidance

Alternate Link to Reuse 

Fact Sheet or Report

Nevada

Nevada Administrative Code, Chapter 

445A, Sections 274 - 280; WTS-1A 

General design criteria for reclaimed 

water irrigation use; WTS-1B General 

design criteria for preparing an effluent 

management plan; WTS-3 Guidance 

Document For An Application For 

Rapid Infiltration Basins; WTS-7 

Guidance Document for Reclaimed 

Water Storage Ponds

http://www.leg.state.nv.us/nac/nac445a.html#NAC445ASec275http://ndep.nv.gov/bwpc/f

act01.htm

Nevada - 

additional http://ndep.nv.gov/admin/nrs.htm

New Hampshire No regulations or guidelines at this 

time

http://des.nh.gov/organization/comm

issioner/legal/rules/index.htm#water

New Jersey http://www.state.nj.us/dep/dwq/714a

.htm 

http://www.state.nj.us/de

p/dwq/techmans/reusem

an.pdf

New Mexico

NMED Ground Water Quality Bureau 

Guidance: Above Ground Use of 

Reclaimed Domestic Wastewater

http://www.nmenv.state.nm.us/gwb/

documents/NMED_REUSE_1-24-

07.pdf 

http://www.rmwea.org/reu

se/NewMexico.html 

New Mexico - 

additional

http://www.nmenv.state.nm.us/gwb/

NMED-GWQB-Regulations.htm 

New York Web Address could not be located 

at time of publication.

North Carolina

15A North Carolina Administrative 

Code Subchapter 02U – Reclaimed 

Water

http://reports.oah.state.nc.us/ncac.a

sp?folderName=\Title%2015A%20-

%20Environment%20and%20Natura

l%20Resources\Chapter%2002%20-

%20Environmental%20Management 

http://reports.oah.state.nc

.us/ncac/title%2015a%20

-

%20environment%20and

%20natural%20resource

s/chapter%2002%20-

%20environmental%20m

anagement/subchapter%

20u/subchapter%20u%2

0rules.html

North Dakota

Criteria for Irrigation with Treated 

Wastewater; Recommended Criteria 

for Land Disposal of Effluent

http://www.ndhealth.gov/WQ/

Ohio http://www.epa.state.oh.us/portals/3

5/rules/42-13.pdf

http://www.epa.state.oh.u

s/portals/35/rules/42-

13_factsheet_feb08.pdf 

Ohio - additional http://www.epa.state.oh.us/dsw/pti/in

dex.aspx

Oklahoma

OAC 252:656 "Water Pollution Control 

Construction Standards; OAC 252:627 

Operation and Maintenance of Water 

Reuse; These regulaitons OAC 

252:656 Subchapter 27 and OAC 

252:627 are proposed. 

http://www.deq.state.ok.us/rules/656

.pdf

http://normantranscript.co

m/x1552633625/City-ofNorman-considers-usingreclaimed-water-forpurposes 

Oklahoma - 

additional

http://www.deq.state.ok.us/rules/627

.pdf

Oregon Oregon Administrative Rules, Division 

55 - Recycled Water Use

http://arcweb.sos.state.or.us/pages/r

ules/oars_300/oar_340/340_055.ht

ml 

http://www.deq.state.or.u

s/wq/reuse/reuse.htm
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse

2012 Guidelines for Water Reuse C-5 

State Title of Regulations or Guidelines

Link to State Reuse Regulations 

or Guidance

Alternate Link to Reuse 

Fact Sheet or Report

Pennsylvania

Manual for Land Treatment of 

Wastewater; Reuse of Treated 

Wastewater Guidance Manual

http://www.elibrary.dep.state.pa.us/d

sweb/Get/Document-88575/385-

2188-002.pdf

http://www.elibrary.dep.st

ate.pa.us/dsweb/View/Co

llection-10105

Puerto Rico Web Address could not be located 

at time of publication.

Rhode Island

http://www.dem.ri.gov/programs/ben

viron/water/permits/wtf/pdfs/reusegy

d.pdf

South Carolina

Section 67.300 of South Carolina 

Regulation 61-67, Standards for 

Wastewater Facility Construction 

"State Land Application Permit"

http://www.scdhec.gov/environment/

water/landpage.htm

South Dakota http://www.denr.sd.gov/des/sw/docu

ments/DesignCriteriaManual.pdf. 

South Dakota - 

additional

http://legis.state.sd.us/statutes/Displ

ayStatute.aspx?Type=StatuteChapt

er&Statute=34A-2

Tennessee www.tn.gov/environment/permits/wq

operm.shtml

www.tn.gov/environment/

wpc/publications/#tech 

Tennessee - 

additional

http://denr.sd.gov/des/sw/eforms/D0

449V1-a_potw_appl.pdf 

Texas http://www.tceq.texas.gov/rules/indx

pdf.html#210 

US Virgin 

Islands

Web Address could not be located 

at time of publication.

Utah Reuse requirements moved to UCA 

R317-3-11 (from UCA R317-1-2). 

http://www.rules.utah.gov/publicat/co

de/r317/r317-001.htm#T4 

http://www.rules.utah.gov

/publicat/code/r317/r317-

003.htm#T11

Vermont Environmental Protection Rules, 

Chapter 14, Indirect Discharge Rules

http://www.anr.state.vt.us/dec/ww/rul

es.htm#os 

http://www.anr.state.vt.us

/dec/ww/Rules/IDR/Adopt

ed-IDR-4-30-03.pdf

Virginia

Virginia Administrative Code Agency 

25, Chapter 740 - Water Reclamation 

and Reuse Regulation

http://lis.virginia.gov/000/reg/TOC09

025.HTM#C0740

Washington Chapter 90.46 Revised Code of 

Washington - Reclaimed water use

http://apps.leg.wa.gov/rcw/default.as

px?cite=90.46&full=true 

http://www.ecy.wa.gov/pr

ograms/wq/reclaim/index.

html 

West Virginia

Title 64 Series 47 Chapter 16-1 

Sewage Treatment and Collection 

System Design Standards

http://apps.sos.wv.gov/adlaw/csr/rul

eview.aspx?document=2802

Wisconsin

Domestic Wastewater to Subsurface 

Soil Absorption Systems Permit (WI0062901-2)

http://dnr.wi.gov/org/water/wm/ww/st

atauth.htm

Wyoming

Chapter 21 Water Quality Rules - 

Standards for the Reuse of Treated 

Wastewater

http://soswy.state.wy.us/Rules/RUL

ES/2804.pdf

http://deq.state.wy.us/wq

d/WQDrules/index.asp
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse

C-6 2012 Guidelines for Water Reuse

This page intentionally left blank.
2012 Guidelines for Water Reuse D-1 

APPENDIX D 

U.S. Case Studies 

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

D-5 US-AZ-Gilbert Town of Gilbert Experiences Growing Pains 

in Expanding the Reclaimed Water System Guy Carpenter, P.E. (Carollo Engineers)

D-7 US-AZ-Tucson Tucson Water: Developing a Reclaimed 

Water Site Inspection Program Karen Dotson (Retired, Tucson Water) 

D-10 US-AZ-Sierra Vista Environmental Operations Park Kerri Jean Ormerod (University of 

Arizona)

D-12 US-AZ-Phoenix 91st Avenue Unified WWTP Targets 100

Percent Reuse

Steve Rohrer, P.E. and Tim Francis, 

P.E., BCEE (Malcolm Pirnie, the Water 

Division of ARCADIS); Andrew Brown, 

P.E. (City of Phoenix)

D-14 US-AZ-Blue Ribbon 

Panel

Arizona Blue Ribbon Panel on Water 

Sustainability

Channah Rock, PhD (University of 

Arizona); Chuck Graf, R.G. (Arizona 

Department of Environmental Quality); 

Christopher Scott, PhD (University of 

Arizona); Jean E.T. McLain, PhD 

(USDA-Agricultural Research Service, 

U.S. Arid Land Agricultural Research 

Center); and Sharon Megdal, PhD 

(University of Arizona)

D-18 US-AZ-Prescott 

Valley Effluent Auction in Prescott Valley, Arizona Christopher Scott, PhD (University of 

Arizona)

D-20 US-AZ-Frito Lay Frito-Lay Process Water Recovery 

Treatment Plant, Casa Grande, Arizona Al Goodman, P.E. (CDM Smith)

D-22 US-CA-Psychology

The Psychology of Water Reclamation and 

Reuse Survey: Findings and Research 

Roadmap

Brent M. Haddad, MBA, PhD (University 

of California, Santa Cruz)

D-24 US-CA-San Ramon

Managing a Recycled Water System 

through a Joint Powers Authority: San 

Ramon Valley

David A. Requa, P.E. (Dublin San 

Ramon Services District)

D-27 US-CA-San Diego City of San Diego – Water Purification 

Demonstration Project

Marsi A. Steirer; Amy Dorman, P.E.; 

Anthony Van; and Joseph Quicho

(City of San Diego Public Utilities 

Department)

D-30 US-CA-Orange 

County

Groundwater Replenishment System, 

Orange County, California

Mike Markus, P.E., D.WRE; Mehul 

Patel, P.E.; William Dunivin (Orange 

County Water District)

D-33 US-CA-North City EDR at North City Water Reclamation Plant Eugene Reahl and Patrick Girvin (GE)

D-35 US-CA-Santa Cruz Water Reuse Study at the University of 

California Santa Cruz Campus

Tracy A. Clinton, P.E. (Carollo 

Engineers)

D-38 US-CA-Monterey

Long-term Effects of the Use of Recycled 

Water on Soil Salinity Levels in Monterey 

County

B.E. Platts (Monterey Regional Water 

Pollution Control Agency)

D-40 US-CA-Southern 

California MWD

Metropolitan Water District of Southern 

California’s Local Resource Program

Raymond Jay (Metropolitan Water 

District)

1 To search for case studies by region or by category of reuse, please refer to Figure 5-2.
Appendix D | U.S. Case Studies

D-2 2012 Guidelines for Water Reuse

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

D-42 US-CA-Los Angeles 

County

Montebello Forebay Groundwater Recharge 

Project using Reclaimed Water, Los Angeles 

County, California

Monica Gasca, P.E. and Earle Hartling 

(Los Angeles County Sanitation 

Districts)

D-46 US-CA-Elsinore 

Valley Recycled Water Supplements Lake Elsinore Ronald E. Young, P.E., DEE (Elsinore 

Valley Municipal Water District)

D-48 US-CA-Temecula Replacing Potable Water with Recycled 

Water for Sustainable Agricultural Use

Graham Juby, PhD, P.E. (Carollo 

Engineers)

D-51 US-CA-Santa Ana 

River

Water Reuse in the Santa Ana River 

Watershed

Celeste Cantú (Santa Ana Watershed 

Project Authority)

D-53 US-CA-Vander Lans Leo J. Vander Lans Water Treatment 

Facility

R. Bruce Chalmers, P.E. (CDM Smith) 

and Paul Fu, P.E. (Water 

Replenishment District)

D-55 US-CAPasteurization

Use of Pasteurization for Pathogen 

Inactivation for Ventura Water, California

Andrew Salveson, P.E. (Carollo 

Engineers)

D-57 US-CA-Regulations California State Regulations James Crook, PhD, P.E., BCEE (Water 

Reuse Consultant)

D-61 US-CA-West Basin West Basin Municipal Water District: Five

Designer Waters

Shivaji Deshmukh, P.E. (West Basin 

Municipal Water District)

D-63 US-CO-Denver Zoo Denver Zoo

Abigail Holmquist, P.E. (Honeywell); 

Damian Higham (Denver Water); and 

Steve Salg (Denver Zoo)

D-65 US-CO-Denver Denver Water

Abigail Holmquist, P.E. (Honeywell);

Mary Stahl, P.E. (Olsson Associates); 

and Steve Price, P.E. (Denver Water)

D-68 US-CO-Denver 

Energy Xcel Energy’s Cherokee Station Abigail Holmquist, P.E. (Honeywell) and Damian Higham (Denver Water)

D-70 US-CO-Denver Soil Effects of Recycled Water on Soil Chemistry Abigail Holmquist, P.E. (Honeywell) and 

Damian Higham (Denver Water)

D-73 US-CO-Sand Creek Sand Creek Reuse Facility Reuse Master 

Plan 

Bobby Anastasov, MBA and Richard 

Leger, CWP (City of Aurora)

D-76 US-CO-Water 

Rights Water Reuse Barriers in Colorado Cody Charnas (CDM Smith)

D-77 US-DC-Sidwell 

Friends

Smart Water Management at Sidwell 

Friends School

Laura Hansplant, RLA, ASLA, LEED AP

(Andropogon Associates [formerly]

and Roofmeadow) and Danielle 

Pieranunzi, LEED AP BD+C 

(Sustainable Sites Initiative)

D-80 US-FL-Miami So 

District Plant South District Water Reclamation Plant

R. Bruce Chalmers, P.E. (CDM Smith) 

and James Ferguson (Miami Dade 

Water and Sewer Department)

D-83 US-FL-Pompano 

Beach City of Pompano Beach OASIS A. Randolph Brown and Maria Loucraft (City of Pompano Beach)

D-85 US-FL-Orlando E. 

Regional

Eastern Regional Reclaimed Water 

Distribution System 

Victor J. Godlewski Jr. (City of Orlando); 

Greg D. Taylor, P.E. and Karen K. 

McCullen, P.E., BCEE (CDM Smith)

D-87 US-FL-Economic 

Feasibility

Economic Feasibility of Reclaimed Water to 

Users

Grace M. Johns, PhD (Hazen and 

Sawyer) and C. Donald Rome, Jr. 

(Southwest Florida Water Management 

District)

D-90 US-FL-Reedy Creek Reuse at Reedy Creek Improvement District Ted McKim, P.E., BCEE (Reedy Creek 

Improvement District)

D-93 US-FL-Marco Island Marco Island, Florida, Wastewater 

Treatment Plant 

Jennifer Watt, P.E. (General Electric); 

Solomon Abel, P.E. (CDM Smith); and 

Rony Joel, P.E., DEE (AEC Water)
Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse D-3 

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

D-96 US-FL-Everglade 

City Everglade City, Florida Rony Joel, P.E., DEE (AEC Water)

D-98 US-FL-Orlando 

Wetlands City of Orlando Manmade Wetlands System Mark Sees (City of Orlando)

D-99 US-FL-SWFWMD 

Partnership

Regional Reclaimed Water Partnership 

Initiative of the Southwest Florida Water 

Management District

Alison Ramoy (Southwest Florida Water 

Management District)

D-102 US-FL-Altamonte 

Springs 

The City of Altamonte Springs: Quantifying 

the Benefits of Water Reuse David Ammerman, P.E. (AECOM)

D-104 US-FL-Clearwater Evolution of the City of Clearwater’s 

Integrated Water Management Strategy

Laura Davis Cameron, BSBM; Tracy 

Mercer, MBA;

Nan Bennett, P.E.; and Rob Fahey, P.E. 

(City of Clearwater Public Utilities)

D-107 US-FL-Turkey Point Assessing Contaminants of Emerging 

Concern (CECs) in Cooling Tower Drift

James P. Laurenson (HEAC) and 

Edward L. Carr (ICF International)

D-110 US-GA-Clayton 

County

Sustainable Water Reclamation Using 

Constructed Wetlands: The Clayton County 

Water Authority Success Story

Veronica Jarrin, P.E. and Jim Bays, 

P.W.S (CH2M HILL); Jim Poff (Clayton 

County Water Authority)

D-113 US-GA-Forsyth 

County

On the Front Lines of a Water War, 

Reclaimed Water Plays a Big Role in 

Forsyth County, Georgia

Daniel E. Johnson, P.E. (CDM Smith)

D-115 US-GA-Coca Cola Recovery and Reuse of Beverage Process 

Water

Dnyanesh V Darshane, PhD, MBA; 

Jocelyn L. Gadson, PMP; Chester J. 

Wojna; Joel A. Rosenfield, Henry Chin, 

PhD; Paul Bowen, PhD (The Coca-Cola 

Company)

D-118 US-HI-Reuse Reclaimed Water Use in Hawaii Elson C. Gushiken (ITC Water 

Management, Inc.)

D-121 US-MASouthborough

Sustainability and LEED Certification as 

Drivers for Reuse: Toilet Flushing at The 

Fay School

Mark Elbag (Town of Holden)

D-123 US-MA-Hopkinton

Decentralized Wastewater Treatment and 

Reclamation for an Industrial Facility, EMC 

Corporation Inc., Hopkinton, Massachusetts

Mike Wilson, P.E. (CH2M Hill)

D-124 US-MA-Gillette 

Stadium

Sustainability and Potable Water Savings as 

Drivers for Reuse: Toilet Flushing at Gillette 

Stadium

Mike Wilson, P.E. (CH2M Hill)

D-126 US-ME-Snow Snowmaking with Reclaimed Water Don Vandertulip, P.E., BCEE (CDM 

Smith) 

D-129 US-MN-Mankato Reclaimed Water for Peaking Power Plant: 

Mankato, Minnesota

Mary Fralish (City of Mankato) and Patti 

Craddock (Short Elliott Hendrickson 

Inc.)

D-132 US-NC-Cary Town of Cary, North Carolina, Reclaimed 

Water System

Leila R. Goodwin, P.E. (Town of Cary) 

and Kevin Irby, P.E. (CDM Smith)

D-134 US-NY-PepsiCo Identifying Water Streams for Reuse in 

Beverage Facilities: PepsiCo ReCon Tool

Liese Dallbauman, PhD (Pepsi-Co 

Global Operations)

D-136 US-PA-Kutztown The Water Purification Eco-Center Jeff Moyer and Christine Ziegler Ulsh 

(Rodale Institute)

D-139 US-PA-Mill Run

Zero-Discharge, Reuse, and Irrigation at 

Fallingwater, Western Pennsylvania 

Conservancy

Mike Wilson, P.E. (CH2M Hill)

D-141 US-TN-Franklin Franklin, Tennessee Integrated Water 

Resources Plan

Jamie R. Lefkowitz, P.E. and Kati Bell, 

PhD, P.E. (CDM Smith); and Mark Hilty, 

P.E. (City of Franklin)
Appendix D | U.S. Case Studies

D-4 2012 Guidelines for Water Reuse

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

D-145 US-TX-San Antonio San Antonio Water System Water Recycling 

Program 

Pablo R. Martinez (San Antonio Water 

System)

D-148 US-TX-Big Spring Raw Water Production Facility: Big Spring 

Plant

David W. Sloan, P.E., BCEE (Freese 

and Nichols)

D-150 US-TX-Landscape 

Study

Site Suitability for Landscape Use of 

Reclaimed Water in the Southwest

Seiichi Miyamoto, PhD and Ignacio 

Martinez (Texas A&M Agrilife Research 

Center at El Paso)

D-152 US-TX-NASA U.S. Water Recovery System on the 

International Space Station

J. Torin McCoy (NASA Johnson Space 

Center)

D-154 US-TX-Wetlands East Fork Raw Water Supply Project: A 

Natural Treatment System Success Story

Ellen T. McDonald, PhD, P.E. and Alan 

H. Plummer, Jr., P.E., BCEE (Alan 

Plummer Associates Inc.) and James M. 

Parks, P.E. (North Texas Municipal 

Water District)

D-157 US-VA-Occoquan Potable Water Reuse in the Occoquan 

Watershed

Robert W. Angelotti (Upper Occoquan 

Service Authority) and Thomas J. 

Grizzard, PhD, P.E. (Virginia Tech)

D-160 US-VA-Regulation Water Reuse Policy and Regulation in 

Virginia 

Valerie Rourke, CPSS, LPSS, CNMP 

(Virginia Department of Environmental 

Quality)

D-163 US-WA-Sequim

City of Sequim’s Expanded Water 

Reclamation Facility and Upland Reuse 

System 

Chad Newton, P.E. (Gray & Osborne, 

Inc.)

D-166 US-WA-Regulations Washington State Regulations

Chad Newton, P.E. (Gray and Osborne, 

Inc.) and Craig Riley, P.E. (Washington 

State Department of Health)

D-169 US-WA-King County Demonstrating the Safety of Reclaimed 

Water for Garden Vegetables

Sally Brown, PhD (University of 

Washington)

D-172 US-WA-Yelm City of Yelm, Washington Shelly Badger (City of Yelm)
2012 Guidelines for Water Reuse

Town of Gilbert Experiences Growing Pains in Expanding 

the Reclaimed Water System

Author: Guy Carpenter, P.E. (Carollo Engineers) 

US-AZ-Gilbert

Project Background or Rationale 

The Town of Gilbert, population 208,453, is a 73 mi2

(190-km2

First, Gilbert is several miles away from any possible 

discharge outfall to receiving waters (such as a river or 

lake), so there was no cost effective disposal option for 

treated wastewater. Second, the State of Arizona 

Groundwater Management Act’s stringent water 

conservation requirements (which regulate all sources 

of water, not just groundwater) encourage the use of 

reclaimed water to maintain compliance with the act. 

The Act was adopted in 1980 to stop the rapid decline 

of aquifer water levels and for Arizona to receive 

congressional approval to build the Central Arizona 

Project, the 336-mile (540 km) canal that brings 

Colorado River water to Arizona’s largest urban and 

agricultural centers. These factors encouraged town 

leaders to install a reclaimed water distribution system 

with connections required for new development, 

thereby ensuring a systematic and cost-effective 

expansion of the system. 

) city located in the Phoenix, Arizona, 

metropolitan area. By 1986, and with a population of 

over 11,000, Gilbert’s rudimentary sewage treatment 

system was replaced by a facility that produced 

reclaimed water of sufficient quality for open access 

urban irrigation. While Gilbert had a water resources 

portfolio sufficient to meet near-term water demands, 

there were a number of drivers for Gilbert to implement 

reuse. 

Reclaimed water is an important element of the town’s 

ability to demonstrate a 100-year assured water supply 

(a requirement of the act), a designation without which 

the town would be subject to a state-imposed growth 

moratorium. 

Capacity and Type of Reuse 

Application 

Gilbert operates two WRFs that treat produce A+ 

quality reclaimed water, with a loss of approximately 8 

to 10 percent of the influent total to solids treatment. 

The Neely Water Reclamation Facility (WRF) has a 

treatment capacity of 11 mgd (482 L/s). The Greenfield 

WRF is a joint facility operated in partnership with the 

city of Mesa and the town of Queen Creek. The plant 

capacity is currently 16 mgd (700 L/s), with 8 mgd (350 

L/s) of capacity available to Gilbert, and is planned to 

be expanded to treat up to 42 mgd (1840 L/s), with 

Gilbert’s share of the capacity at 16 mgd (700 L/s). 

Reclaimed water was initially used by a single 

customer, the town parks and recreation department.

Over the past two decades, with rapid population 

growth, the system has expanded to include a 

distribution system throughout newly developed areas, 

the Riparian Preserve at Water Ranch, the South 

Recharge facilities, and eight facilities. The town of 

Gilbert now has over 60 miles (96 km) of reclaimed 

water transmission mains and approximately 37 

reclaimed water customers.

In addition to reclaimed water distribution, because 

Gilbert is committed to 100 percent reuse, reclaimed 

water that is not used in the distribution system is 

recharged for the purpose of accumulating Long Term 

Storage Credits, which are utilized to offset current 

and future groundwater pumping, as well as to firm up 

the Assured Water Supply. Recharge facilities consist 

of percolation basins and injection wells. 

Initial Phase of Implementation 

In 1986, the new reclamation facility provided water to 

the Town’s first regional park, Freestone Park, which is 

approximately two miles east of the Neely WRF. 

Freestone Park is a 60-acre (24 hectares) multi-use 

park with two attractive, non-recreational lakes out of 

which reclaimed water is pressurized and distributed 

throughout the park for spray irrigation. 

Soon after the construction of the Neely WRF, a rapid 

increase in population growth and lack of additional 

reclaimed water customers forced Gilbert to look at 

alternatives. The evaporation ponds that were 

constructed to receive reclaimed water that was not 

otherwise used by the park were under capacity. 

D-5
Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Because evaporating the unused reclaimed water did 

not meet the objectives of the Groundwater 

Management Act, the evaporation ponds on 35 ac (14 

ha), adjacent to the Neely WRF were converted to 

recharge basins in 1989. 

Growing Pains and Lessons Learned 

As the town continued to grow, additional reclaimed 

water customers eventually responded to the 

availability of the inexpensive and continuous supply of 

reclaimed water. Additionally, recharge basins were 

expanded by another 40 ac (16 ha) and in response to 

suggestions by the public, the recharge facility was 

enhanced to include habitat for native and migratory 

birds. 

At the time of the town’s implementation of the 

reclaimed water system, there were no state, county, 

regional, or local construction standards specifically for 

reclaimed water systems. Several design issues 

caused operational problems. Basic, regional potable 

water system construction standards were used for 

expansion of the reclaimed water system, but valve 

spacing was allowed to be greater than that in the 

potable system. Thus, when breaks occurred, draining 

the lines for repair took significant time and reclaimed 

water cannot be drained to a retention basin without a 

permit, so management of a break was a labor and 

administrative intensive effort. Other challenges were 

related to developer-installed reclaimed water pipeline 

additions which often had valve boxes of the same 

specification as the potable water system. This caused 

confusion for operators and utility locators attempting 

to respond to system breaks and water delivery 

changes; incorrect valves were opened and closed 

due to the lack of differentiating features. This was 

also problematic from a health and safety standpoint.

Positive changes also occurred at this time, such as 

reclaimed water identification standards. To ensure 

compliance with its reuse permit through the state, and 

to provide limited system design guidance to 

developers, the town developed a reclaimed water 

user’s manual. Along with the manual, each customer, 

except Gilbert Parks and Recreation, was required to 

enter a reclaimed water use agreement stipulating 

requirements and an annual volume of water that must 

be taken by the customer.

In 1999, in response to increasing conservation 

requirements, the mayor formed an “ad hoc” water 

conservation committee made up of the mayor, two 

council members, landowners, developers, engineers, 

and the large untreated water providers whose service 

areas overlapped the town of Gilbert water service 

area. Accurate information regarding the complexities 

of water resource management was conveyed and 

understood by stakeholders and the attitude of 

“disposing” reclaimed water was effectively overcome, 

and the importance of reclaimed water was finally 

understood. 

Also in 1999, and in response to the need to recharge 

water to offset groundwater pumping debits and to 

manage “excess” reclaimed water associated with 

seasonal demand fluctuations, a second basin 

recharge facility was constructed on 120 ac (49 ha). 

Following the success of the original recharge facility’s 

habitat enhancements, the new facility (called the 

Riparian Preserve at Water Ranch) was designed as 

an open-access, passive recreation park, in addition to 

a fully functional recharge facility (Figure 1). 

Expansion 

In 2005, the South Recharge Facility was constructed 

to accommodate increases in wastewater flows from 

the Greenfield Water Reclamation Plant, which began 

operation in 2005. In 2006, the Town’s integrated 

water resources master plan was updated to guide the 

allocation of reclaimed water to ensure a long-term 

water supply.

Figure 1

Reclaimed water sustains a diverse wildlife habitat at 

the Gilbert Riparian Preserve, while replenishing the 

regional aquifer (Photo credit: Patty Jordan, Town of 

Gilbert)

D-6
2012 Guidelines for Water Reuse

Tucson Water: Developing a Reclaimed Water Site 

Inspection Program

Author: Karen Dotson (Retired, Tucson Water)

US-AZ-Tucson

Project Background or Rationale 

The city of Tucson is part of a metropolitan area of 

over 1 million people in the northern semi-arid reaches 

of the Sonoran Desert in eastern Pima County, 

Arizona. The City owns and operates Tucson Water, 

the largest regional municipal water utility in the area. 

Tucson Water provides potable water to about 75 

percent of the metropolitan area’s population and nonpotable reclaimed water service in the City and three 

other governmental jurisdictions. Recognizing the 

importance of maintaining public safety, protecting the 

quality of water supplies, and fostering a positive 

public perception of reclaimed water for non-potable 

purposes, Tucson Water developed a program to 

periodically inspect all sites having reclaimed water 

service. This program includes training and

certification for staff conducting testing at reclaimed 

water sites.

Capacity and Type of Reuse 

Application 

Until 1993, when Colorado River water was introduced 

as part of the potable water supply, the Tucson area 

relied exclusively on pumped groundwater. Today, 

Colorado River water makes up over half of Tucson 

Water’s potable supplies –approximately 98,000 acft/yr (121 MCM/yr) as of 2010. In 2010, 15,000 ac-ft 

(18.5 MCM) were delivered to over 900 reclaimed 

water customers – water that would otherwise have 

been drawn from the potable water system of Tucson 

Water or another water provider. Fifty-six percent of 

the deliveries went to 18 golf courses; another 17 

percent was delivered to parks. The remainder was 

delivered to schools (8 percent), other water providers 

(13 percent), and single family, agriculture, 

commercial, multi-family, and street landscape 

irrigation (6 percent).

Reuse Treatment Technology 

Since 1984, Tucson Water has operated its reclaimed 

water system while systematically expanding it to 

accommodate areas of growing customer demand. 

Today, the system has more than 160 miles (257 km) 

of pipeline and 15 million gallons (57,000 m3

1. Secondary effluent from Pima County’s Roger 

Road WWTP that receives additional filtration and 

disinfection at Tucson Water’s Filtration Plant 

) of 

surface storage. Reclaimed water is produced in three 

ways and depending on the demand, water from a 

combination of the sources below is delivered through 

the Reclaimed Water System:

2. Secondary effluent from Pima County’s Roger 

Road WWTP that is recharged in constructed 

basins or the Santa Cruz River and later 

recovered and disinfected 

3. Tertiary effluent from Pima County’s Randolph 

Park WWTP 

The average daily delivery of reclaimed water is 13.5 

mgd (657 L/s), and the summer peak delivery is 

approximately 31 mgd (1358 L/s).

Project Description 

1. Until 2010, Tucson Water only inspected sites with 

reclaimed water service once (prior to the initiation 

of service). At these inspections, a Tucson Water 

cross-connection control specialist checked the 

site for compliance with state and local regulations 

and conducted a dye test (Figure 1) to identify 

cross-connections. A manual was developed to 

guide cross-connection control specialists step-bystep through the dye test procedure (Tucson 

Water, 2010). The Reclaimed Water Site 

Inspection Program was implemented in phases:

2. Adoption of an ordinance requiring periodic 

reclaimed water site inspections

3. Development of a Reclaimed Water Site Testers 

Certification Program and training manual for 

Reclaimed Water Site Testers

4. Development of a training program

D-7
Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

5. Inspection of reclaimed water sites

The first phase of implementation of the Reclaimed 

Water Site Inspection Program was the adoption of a 

2010 ordinance requiring all reclaimed water sites to 

be inspected periodically, with provisions including the 

following:

 Annual inspections for schools, parks, and

commercial sites

 Residential site inspections once every five 

years

 Inspection of non-residential sites by a private 

sector certified Reclaimed Water Site Tester 

beginning in 2015

The second phase included development of a 

reclaimed water site database and Reclaimed Water 

Site Testers certification program. Tucson Water’s 

backflow prevention online database was modified to 

allow the addition of reclaimed water site information 

and the results of Reclaimed Water Site Testers’ site 

inspections the same way that the annual backflow 

prevention assembly tests are entered.

The Reclaimed Water Site Testers certification 

program requires attendance at an eight-hour class 

instructed by Tucson Water, and a passing score on a 

written examination. Re-certification is required every 

three years. Because the site inspection program 

focused heavily on prevention and identification of 

cross-connections, Tucson Water required that a 

current certification as a Backflow Prevention Tester 

from a recognized agency, (e.g. AWWA or American 

Backflow Prevention Association), would be required. 

The Tucson Water Cross-connection Control 

Specialists developed a training manual that includes 

chapters addressing: Tucson Water’s reclaimed water 

system, Tucson Water’s responsibilities, reclaimed 

water customers’ responsibilities, and reclaimed water 

site testers’ responsibilities; concepts addressed 

include:

 Ensuring that reclaimed water sites comply with 

state and local regulations

 Visiting a reclaimed water site and hands on

experience conducting pressure tests

 Reporting cross-connections to Tucson Water 

and the customer

 Entering test results online into Tucson Water’s 

database

Tucson Water conducts Reclaimed Water Site Tester 

classes several times a year and has certified more 

than 30 Reclaimed Water Site Testers. The initial 

classes were attended by cross-connection control 

specialists from Tucson Water and the Peoria, Arizona 

Public Works Utilities Department, and backflow 

prevention testers from the City of Tucson Parks and 

Transportation Departments, Pima County Natural 

Resources and Transportation Departments, Tucson 

Unified School District, the University of Arizona, and 

the Arizona Department of Environmental Quality 

(ADEQ). The ADEQ has approved the class for eight 

hours of professional development credit.

The Tucson Water Cross-connection Control 

Specialists are now working closely to mentor newly 

certified Reclaimed Water Site Testers as they begin 

inspecting schools, parks, and street medians. The 

mentoring program provides confidence that sites are 

being correctly inspected and tested and gives the 

new Site Testers a positive environment in which to 

ask questions. In 2013 Tucson Water Site Testers will 

begin inspecting residential sites.

Project Funding and Management 

Practices 

The Reclaimed Water Site Inspection Program was 

developed by existing staff from the Backflow 

Prevention/Reclaimed Water Section. The only new 

expense for the Program’s development was $10,000 

for consultant services to modify the backflow 

prevention database to accommodate reclaimed water 

site information. When the program was implemented, 

a fifth cross-connection control specialist was hired 

and the total recurring annual cost for this position, 

including benefits, is $72,000. There was also a onetime $37,000 expense, including a vehicle, equipment, 

and training for the new specialist.

Successes and Lessons Learned

Development of the Reclaimed Water Site Inspection 

Program took more than 5 years from conception to 

implementation. Although the importance of the 

program was recognized, competing priorities often 

overshadowed implementation efforts. Ultimately, the 

D-8
Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

program was implemented as the result of a project 

“champion” within Tucson Water and support from the 

Southern Arizona Office of the ADEQ. Once the 

commitment to implement the program had been 

made, strict adherence to the schedule made its 

completion a reality. 

Tucson Water’s Reclaimed Water Site Inspection 

Program is the first of its type in Arizona and will 

hopefully be used as a model for other programs and a 

template for State certification of Reclaimed Water Site 

Testers.

References

Tucson Water. 2010. Dye Testing: Ensuring the Separation 

of Potable and Reclaimed Water Systems. Available from 

<http://cms3.tucsonaz.gov/files/water/docs/dyetesting.pdf>. 

City of Tucson. 2010. Mayor and Council Ordinance: 

Requiring Inspections. Available from 

<http://cms3.tucsonaz.gov/sites/default/files/water/docs/back

flow-ordinance.pdf>.

Tucson Water. 2010. A Training Manual for Reclaimed 

Water Site Testers. Available at 

<http://cms3.tucsonaz.gov/files/water/docs/recl-train-1-

2.pdf>.

D-9
2012 Guidelines for Water Reuse

Environmental Operations Park

Author: Kerri Jean Ormerod (University of Arizona)

US-AZ-Sierra Vista

Project Background or Rationale 

The key water management challenges in Arizona are 

increasing demands for water, fully allocated existing 

water resources, and groundwater depletion. 

Groundwater depletion, or overdraft, is a result of 

excessive groundwater pumping and is problematic for 

numerous reasons, including its environmental 

impacts. Groundwater sustains rivers, streams, lakes, 

and wetlands providing the riparian habitat for wildlife. 

In the 19th century, wetlands, marshlands or cienegas, 

were common along rivers in Arizona; however, heavy 

pumping of groundwater beginning in the mid-20th 

century led to dewatered rivers and streams and loss 

of riparian ecosystems (Glennon, 2002). 

Recently, artificially constructed wetlands have been 

designed to simultaneously provide natural wastewater 

treatment and enhance wildlife habitat. Environmental 

Operations Park (EOP) in southern Arizona serves as 

a case study, where water from the wastewater 

reclamation facility is polished in constructed wetlands 

and recharged to the local aquifer in order to mitigate 

the adverse impacts of continued groundwater 

pumping in the San Pedro River system. 

The EOP is operated by the city of Sierra Vista, 

Arizona, in Cochise County in the southeastern corner 

of the state. Sierra Vista is adjacent to the upper San 

Pedro River and the U.S. Army’s Fort Huachuca. The 

city and surrounding communities in Cochise County 

are experiencing rapid growth and subsequent 

increases in water demand. The addition of over 

13,500 new residents between 2000 and 2010 

represented a 12 percent change in population (U.S. 

Census Bureau, 2010) and by 2025 an estimated 

7,000 ac-ft (8.6 MCM) will be necessary to serve the 

projected population (Glennon, 2002). Cochise county 

communities rely on the groundwater resources in the 

Sierra Vista sub-watershed, part of the bi-national San 

Pedro Watershed. Within the watershed, the San 

Pedro River flows north from Mexico into Arizona. The 

river is distinct as the last free-flowing undammed river 

in Arizona, which supports a unique desert riparian 

ecosystem. The wells supporting Sierra Vista and Fort 

Huachuca have created cones of depression that 

threaten the surface flow of the river (Glennon, 2002). 

While there is technically sufficient groundwater to 

sustain the rising population in and around Sierra 

Vista, a significant drop in the water table will reduce 

the amount of water available to the river and its 

riparian vegetation. Ecological considerations, 

including the protection of endangered species, 

prompted the decision to recharge available reclaimed

water supplies to the underlying aquifer. 

The ecological importance of Arizona’s San Pedro 

River was recognized by Congress in 1988 when it 

established the San Pedro Riparian National 

Conservation Area with the explicit mission to protect 

approximately 40 miles (64 km) of the river and its 

riparian habitat. The San Pedro River system provides 

habitat for over two-thirds of all bird species in North 

America and is an internationally renowned attraction 

for birders (Glennon, 2002; Sprouse, 2005). In addition 

to the hundreds of bird species, the San Pedro 

provides habitat 82 mammals, 43 reptiles, including 

seven federally recognized endangered species 

(Sprouse, 2005). 

In Sierra Vista, reclaimed water functions solely as a 

water supply for aquifer recharge. The artificial 

recharge occurs a couple miles from the San Pedro 

River with the ultimate goal of safe yield (balance 

between water withdraw and natural and artificial 

recharge). The immediate goal of the recharge is to 

mitigate groundwater pumping by creating a mound 

between the existing cone of depression and the San 

Pedro River in order to protect baseflow of the river. 

Capacity and Type of Reuse 

Application 

The Sierra Vista EOP was established as a multi-use 

center. The park spans 640 ac (260 ha) and includes 

30 open basins that recharge nearly 2,000 ac-ft (2.5 

MCM) of reclaimed water to the aquifer on an annual 

basis, 50 ac (20 ha) of constructed wetlands, nearly 

200 ac (81 ha) of native grasslands, and an 1,800 ft2

(170 m2

) wildlife viewing facility. The reclamation 

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facility includes a 10-ac (4-ha) complete mix/partial mix 

lagoon system. 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 treated to tertiary standards naturally.

The primary purpose of EOP is to offset the effects of 

continued groundwater pumping that negatively impact 

the river and protect the habitat for native and 

endangered species. The present volume of 

wastewater generated from the EOP treatment plant is 

2.5 mgd (110 L/s). The facility system capacity is 4 

mgd (175 L/s). Over 11,000 ac-ft (13.5 MCM) of water 

have been recharged since opening in 2002. The 

recharge facility is permitted and monitored by Arizona 

Department of Water Resources, the agency 

responsible for protecting water quality in the state.

Project Funding and Management 

Practices 

The $7.5 million reclamation project at EOP was 

funded through a cooperative agreement with the City 

of Sierra Vista and the Bureau of Reclamation with 

assistance from Arizona Water Protection Fund 

Program and Department of Housing and Urban 

Development. Per the Bureau of Reclamation funding, 

the City of Sierra Vista is required to recharge all 

wastewater at the EOP facility until 2022. 

Institutional/Cultural Considerations 

In response to growing environmental concerns, 

considerable collaborative community effort has been 

made to protect the region’s assets, including the 

watershed, endangered species, and the continued 

presence of Fort Huachuca—the region’s biggest 

employer. The most influential group is the Upper San 

Pedro Partnership, a consortium of interested parties 

including federal, state, and local agencies, 

development groups, and environmental organizations 

committed to actively protecting the river and the fort. 

Successes and Lessons Learned

Reclaimed water is utilized in Sierra Vista to protect 

the San Pedro River from the principal threat of 

increased groundwater pumping associated with 

population growth. The primary benefits reclaimed 

water provides to the region are recreational and 

economic. In addition to providing wastewater 

treatment, the wetlands, foot trails, trees, native 

grasses and animals at EOP are recognized as a 

community amenity. Recharge of reclaimed water 

within the watershed assists in sustaining the 

baseflows of the river and mitigating the damaging 

effects of continued groundwater pumping, helping to 

maintain essential migration corridors for wildlife and 

protect the habitat for endangered species. 

Nonetheless, future development and its associated 

increase in water demand are expected to exacerbate 

the environmental impacts of groundwater overdraft in 

the region (Glennon, 2002). 

References

Glennon, RJ. (2002). Water Follies: Groundwater Pumping 

and the Fate of America's Fresh waters. Washington, D.C: 

Island Press.

Sprouse, T. (2005). Water issues on the Arizona-Mexico 

border, the Santa Cruz, San Pedro and Colorado Rivers. 

Water Resources Research Center, University of Arizona. 

U.S. Census Bureau (2010). Census 2000 Redistricting Data 

(Public Law 94-171) Summary File, Table PL1, and 2010 

Census Redistricting Data (Public Law 94-171) Summary 

File, Table P1.

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2012 Guidelines for Water Reuse

91st Avenue Unified Wastewater Treatment Plant

Targets 100 Percent Reuse

Authors: Steve Rohrer, P.E. and Tim Francis, P.E., BCEE (Malcolm Pirnie, the Water 

Division of ARCADIS); Andrew Brown, P.E. (City of Phoenix)

US-AZ-Phoenix

Introduction 

The 91st Avenue Wastewater Treatment Plant 

(WWTP) treats wastewater from the cities of Glendale, 

Mesa, Phoenix, Scottsdale, and Tempe, Arizona, 

which together constitute the Sub-Regional Operating 

Group (SROG), formed in 1979 and jointly owns the 

WWTP. The 230 mgd (10,100 L/s) facility uses 

nitrification/denitrification in treating municipal and 

industrial wastewater from the SROG cities. The 

WWTP is one of the largest water reclamation facilities 

in the country. Currently, the plant processes 

approximately 158,000 ac-ft/year (195 MCM/yr), of 

which approximately 60 percent is reused; 67,700 acft/yr (83.5 MCM/yr) is delivered to a nuclear, powergenerating station for cooling tower makeup water, 

1,400 ac-ft/yr (1.7 MCM/yr) is delivered to new 

constructed wetlands, and 28,200 ac-ft (34.8 MCM/yr) 

is delivered to an irrigation company for agricultural 

reuse. The remaining effluent is discharged to the dry

Salt River riverbed that bisects the SROG 

communities.

The 91st Avenue WWTP 

The original 5 mgd (219 L/s) WWTP was built in 1958 

near 91st Avenue and the Salt River in Phoenix. This 

plant was later replaced with a 45 mgd (1,970 L/s) 

plant that was subsequently expanded throughout the 

years. The plant initially discharged secondary treated 

wastewater to the dry Salt River, but in 2000, the 

SROG developed a 25-year Facility Master Plan that 

envisioned a unified plant concept for all future 

expansions. The first project under this plan, the 

Unified Plant 2001 (UP01), was designed in 2001 and 

completed in September 2008, increasing plant 

capacity to 204 mgd (8,900 L/s). The second plant 

expansion project, UP05, was completed in October 

2010 and increased the capacity to the current 230 

mgd (10,100 L/s).

The unified plant concept consists of process units that 

operate as part of an integrated system. Flow from 

each process is combined into a common channel so 

that the following process can be fed to any of the 

subsequent process units. One of the major 

advantages of the unified plant concept is that, in the 

event of a process upset or a scheduled maintenance 

event, a single process unit can be taken out of 

service while maintaining the treatment capacity in 

adjacent and follow-on process areas. Process units 

have been sized with built-in redundancy such that 

follow-on process units with slightly decreased influent 

quality can still satisfy the plant’s permit water quality 

requirements, thus maintaining reliable reclaimed 

water production.

91st Avenue WWTP Water Reuse 

Program 

The 25-Year Master Plan considered the likelihood of 

future advanced treatment that may be required as the 

result of evolving regulations or customer 

requirements. It is estimated that, by 2025, up to 60 

mgd (2630 L/s) of the WWTP effluent could be 

allocated to end uses that require advanced treatment 

and the SROG envisions a Market Resource Center 

on the WWTP site that could include membrane 

filtration and reverse osmosis systems. As a result, 

planning estimates for the development area include 

space on the plant site for advanced treatment 

systems. Currently, the reuse program includes 

several agreements for delivery of the reclaimed 

water, including consideration for future uses of the 

resource. 

Cooling Tower Use at the Palo Verde Nuclear 

Generating Station. SROG’s original water pact with 

the Palo Verde Nuclear Generating Station (PVNGS) 

was signed in 1973 and water deliveries under that 

agreement began in 1985 when the facility’s Unit 1 

began operations. Because of its desert location, the 

PVGNS is the only nuclear power plant in the world 

that uses treated effluent for cooling tower use. 

Treated effluent is piped from the 91st Avenue WWTP 

a distance of 36 miles (58 km) to the PVNGS site, 

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where it is further treated to meet the nuclear energy 

plant's cooling needs. 

The original agreement required SROG to set aside 

105,000 ac-ft/yr (130 MCM/yr) for the PVNGS. And, 

although the plant used considerably less water than 

this, SROG was required to maintain this capacity 

under the terms of the contract. In early 2010, SROG 

and owners of PVNGS renegotiated a new, 

comprehensive water contract which calls for an 

annual allotment of 80,000 ac-ft (98.7 MCM/yr) 

through 2050, freeing up an annual volume of 25,000 

ac-ft (30.8 MCM) for other SROG uses. 

Tres Rios Constructed Wetlands. The SROG 

worked with the U.S. Army Corps of Engineers to 

develop the Tres Rios Constructed Wetlands Project 

along the Salt River downstream of the 91st Avenue 

WWTP. The project will restore eight miles of unique 

riparian habitat near the confluence of the Salt, Gila 

and Agua Fria Rivers using reclaimed water from the 

91st Avenue WWTP. In addition to meeting water 

quality and supply objectives, the project is intended to 

restore habitats for threatened and endangered fish 

and wildlife species, reduce potential for flood 

damage, and provide public recreation opportunities. 

The wetlands were constructed and put into operation 

in 2010 and are currently receiving 1,400 ac-ft/yr (1.7 

MCM/yr) of reclaimed water. It is projected that the 

wetlands can accept 19,000 to 23,000 ac-ft (23 to 28 

MCM) annually as it matures and operations are 

stabilized.

Buckeye Irrigation Company Agricultural 

Irrigation. Buckeye Irrigation Company (BIC) has a 

service area located approximately 20 miles (32 km) 

west of the 91st Avenue WWTP. The company got its 

start in 1907 after many periods of drought, floods, 

economic downturns, changing land and water 

policies, and fiscal uncertainties. Currently, some of 

BIC’s water supply is purchased reclaimed water; BIC 

operates a diversion structure downstream from the 

plant, capturing and diverting reclaimed water 

discharged from the WWTP and/or the Tres Rios 

Constructed Wetlands into agricultural canals. BIC, by 

agreement, can take up to 20,000 ac-ft/yr (25 MCM/yr) 

of effluent through the year 2015, with options to 

extend to 2030.

Potential Future Reuses. Critical riparian and 

wetland habitats along the Salt, Gila and Agua Fria 

Rivers have been lost because of water resources 

development in the Phoenix metropolitan area. In 

addition to the Tres Rios Constructed Wetlands 

project, the SROG cities have evaluated other major 

groundwater recharge and habitat restoration projects 

near these three rivers. The projects will play 

significant roles in the transformation of the 91st 

Avenue WWTP, and likely other area WWTPs, in 

becoming major providers of reclaimed water.

Summary 

The 91st Avenue WWTP currently delivers 60 percent 

of its reclaimed water produced to industrial, wetlands 

and irrigation uses. If current reuse customers take 

their full allotments, the effective reuse rate could be 

as high as 80 percent of the current plant production. 

In addition to increasing deliveries to the wetlands and 

continuing deliveries to the other reclaimed water 

customers, the SROG cities envision implementing 

other regional groundwater recharge and 

environmental and riparian habitat restoration projects. 

These projects, along nearby riverbeds, could accept 

all the remaining reclaimed water that would otherwise 

be discharged to the riverbed. This would effectively 

make the 91st Avenue WWTP the largest water 

reclamation facility in the country whose effluent is 100 

percent reused.

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2012 Guidelines for Water Reuse

To advance water sustainability 

statewide by increasing reuse, 

recycling, and conservation to protect 

Arizona’s water supplies and natural 

environment while supporting 

continued economic development and 

to do so in an effective, efficient and 

equitable manner.

Arizona Blue Ribbon Panel on Water Sustainability

Authors: Channah Rock, PhD (University of Arizona); Chuck Graf, R.G. (Arizona 

Department of Environmental Quality); Christopher Scott, PhD (University of Arizona); 

Jean E.T. McLain, PhD

US-AZ-Blue Ribbon Panel

(USDA-Agricultural Research Service, U.S. Arid Land Agricultural 

Research Center); and Sharon Megdal, PhD (University of Arizona)

Background or Rationale 

In response to the pressure of population growth 

coupled with an arid environment, Arizona has 

conventionally addressed water challenges by 

increasing supply. This case study demonstrates how 

decision-makers are reconsidering the other side of 

the equation—alleviating water demand, especially 

through conservation, recycling, and reuse. In 

particular, the expanding practice of water reuse has 

become the centerpiece of efforts to achieve 

sustainability. 

Blue Ribbon Panel on Water 

Sustainability 

In 2009, Arizona Governor Jan Brewer announced 

formation of the Blue Ribbon Panel on Water 

Sustainability (BRP) to focus on water conservation 

and recycling as strategies to improve water 

sustainability in Arizona. The BRP was jointly chaired 

officials responsible for regulation and management of 

water resources: Ben Grumbles, Director, Arizona 

Department of Environmental Quality (ADEQ); Herb 

Guenther, Director, Arizona Department of Water 

Resources (ADWR); and Kris Mayes, Chairperson, 

Arizona Corporation Commission (ACC), Arizona’s 

constitutionally established regulatory body for 

privately owned utilities. Additionally, 40 members 

representing diverse water interests in Arizona were 

appointed to the BRP, including representatives of 

large and small cities, counties, agriculture, industry, 

Indian Tribes, environmental interests, universities, 

legislative leaders, and other experts. The BRP held 

its first meeting in January 2010 and was challenged 

to identify and overcome obstacles to increase water 

sustainability. The initial goal was to agree upon a 

succinct purpose statement:

Members agreed to provide recommendations on 

statute, rule, and policy changes that, by the year 2020 

in Arizona, would significantly;

1. Increase the volume of reclaimed water reused for 

beneficial purposes in place of raw or potable 

water

2. Advance water conservation, increase the 

efficiency of water use by existing users, and 

increase the use of recycled water for beneficial 

purposes in place of raw or potable water

3. Reduce the amount of energy needed to produce, 

deliver, treat, and reclaim and recycle water by the 

municipal, industrial, and agricultural sectors

4. Reduce the amount of water required to produce 

and provide energy by Arizona power generators

5. Increase public awareness and acceptance of 

reclaimed water uses and the need to work toward 

water sustainability

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BRP Working Groups 

Five working groups were formed, chaired by BRP 

members, with participation open to the public, to 

facilitate discussion of issues and involve broadest 

broad spectrum of stakeholders and technical 

expertise. Working groups were chaired by Arizona 

representatives from Pima County Regional 

Wastewater Reclamation; WateReuse Association; 

Arizona WateReuse Association; Arizona Municipal 

Water Users Association; and Pinal County to explore:

 Public perceptions related to reclaimed water 

reuse quality

 Regulatory and policy changes to further 

promote reuse and recycling

 Reclaimed water infrastructure and retrofit best 

practices

 Conservation/efficiency and energy/water nexus 

issues

 Economic and funding opportunities, including

both public and private mechanisms

The chairs and working group participants 

accomplished substantial work from January through 

November 2010. Cumulatively, 58 meetings were held, 

involving some 320 individuals. The working groups 

identified 40 separate issues, which the BRP

condensed and prioritized. The working groups were 

directed to write "white papers" analyzing these 

challenges and provided recommendations based on 

the analyses. Priority issues included a diversity of 

subjects, including public perception, education, 

research needs, regulatory impediments, efficient use 

of water supplies, expanded use of rainwater and 

storm water, the interface between water and energy, 

funding and incentives.

BRP White Papers 

Subsequent panel meetings were used to provide an 

overview of the 26 issues and to present the 

recommendations developed in the white papers. The 

BRP reviewed recommendations and consolidated 

them into categories: 1) education/outreach, 2) 

standards, 3) information development and research 

agenda, 4) regulatory improvements, and 5) 

incentives. 

BRP Final Report and 

Recommendations 

Although the final report contains too many 

recommendations to summarize here, several 

involving data collection and management stand out 

because they cross all three agencies chairing the 

BRP. Accurate information is essential to promoting a 

common understanding of Arizona's water supplies 

and the extent to which water sustainability is 

achieved. Development of rational policies and 

regulations that encourage use of recycled water while 

protecting public health and safety, and fostering 

public confidence depends on appropriate, timely, and 

accurate data. In addition to data management, a few 

select recommendations of the Panel, relevant to 

reuse are presented. 

Data Management. Most generators and end users of 

reclaimed water submit data manually, which is timeconsuming and often involves more than one permit or 

application. Data may be submitted to one agency and 

the same data or data in a slightly different form may 

be required by another report or agency. Agencies 

store this information in paper files and multiple 

electronic databases, which are hard to access and 

often difficult to compare. This creates administrative 

complexity and added costs for both the regulatory 

agencies and the regulated community, and is not 

conducive to expanding the use of recycled water in 

Arizona. 

The BRP recommended streamlining data submission 

and management as a means of reducing 

administrative burden and improving data quality. 

ADEQ and ADWR would initiate a process to review 

and revise permit and non-permit data submittal 

requirements for frequency, consistency, and 

relevance. Electronic data submittal should be 

standard, and agencies should develop common data 

management systems available to regulators, 

permittees, contractors, and the public. The system 

also should incorporate data needs of the ACC in 

support of their application and review process. The 

BRP also recommended that agencies utilize expertise 

of independent information technology professionals 

and share costs of developing data management 

system(s). 

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Regulatory Programs. Ultimately, the BRP 

recommended no new regulatory programs for reuse 

and water sustainability or major reconstruction of 

existing programs. Instead, less dramatic adjustments 

to Arizona's existing toolbox of water management, 

education, and research capabilities are highlighted.

The BRP concluded that current programs 

administered by ADWR, ADEQ, and the ACC

constitute an exceptional framework within which 

water sustainability and reuse can be pursued.

No major new programs were recommended for 

addressing reuse; this reflected the success of 

transformative rule changes adopted by ADEQ in 

January, 2001. At that time, following more than two 

years of stakeholder involvement, ADEQ adopted 

rules for reclaimed water permits for end users, 

reclaimed water conveyances, and reclaimed water 

quality standards. Simultaneously, ADEQ adopted 

rules requiring modern, high-performance, tertiary 

treatment for new or expanding wastewater treatment 

plants (WWTPs) under BADCT (Best Available 

Demonstrated Control Technology) provisions of its 

Aquifer Protection Permit program. The BADCT 

requirements provide that the high-quality, reclaimed 

water produced is suitable for reuse. This allows the 

permitting program for end users to be simple, 

concentrating on operation, maintenance and reporting 

matters, because end users are delivered high quality 

reclaimed water. Arizona’s modern approach to 

wastewater treatment, combined with comprehensive 

but relatively simple requirements, has incentivized 

reuse throughout the state. Arizona’s rules governing 

reclaimed water and prescribing high-performance 

WWTPs constitute a framework for regulating 

reclaimed water that can be used as a model for other 

states developing their own regulatory programs.

Reclaimed Water Infrastructure Standards. ADEQ 

adopted criteria for reclaimed water distribution 

systems in 2001 for both pipeline and open water 

conveyances; however, these criteria, which pertain to 

design and construction, are quite limited. For 

example, they do not address retrofit situations, 

including conversions of drinking water system piping 

to reclaimed water or vice versa. They insufficiently 

address cross connection control and do not address 

augmentation of the reclaimed water system with other 

sources, such as pumped groundwater. The BRP 

recommended convening a stakeholder group to 

compile a matrix of state, regional and local 

specifications and infrastructure standards to identify 

similarities, inconsistencies, and gaps and develop 

recommendations on a suite of standards to provide a 

common foundation of safety and good engineering 

practices. 

Indirect Potable Reuse (IPR) Guidelines. 

Recognizing trends in other states, the BRP saw a 

need to develop definitions and guidance for IPR to 

clarify and facilitate drinking water source approval 

and local and state agency permitting requirements. 

The BRP believed that IPR guidance would facilitate a 

standardized and efficient approach to design, 

permitting and operation of advanced treatment 

operations with the intent of IPR and suggested that 

regulations be established to address water quality 

standards (regulated and unregulated constituents), 

hydro-geological circumstances of recharge and 

recovery, and multiple/engineered barriers needed to 

obtain approval. Thus, the BRP recommended 

creation of an IPR Multi-Agency Steering Committee 

comprised of diverse membership with the mission to 

develop approaches to streamlining agency reviews, 

incorporating new technologies, and devising a 

statewide policy on IPR. The policy would define the 

objectives of IPR; clarify how recharged reclaimed 

water can become acceptable for potable purposes; 

and outline the process for issuing approvals for IPR 

facilities. 

Next Steps 

Each BRP recommendation can be moved forward by 

the Governor, Legislature, the ACC, ADEQ, and 

ADWR. However, many recommendations involve 

implementation by ADEQ and ADWR, which will be a 

challenge in light of budget cuts that have reduced 

staff and program capabilities. Accordingly, agency 

efforts have recently focused on recommendations 

with university involvement to increase collaboration 

and move forward some of the research issues 

identified by the BRP, ranging from investigations in 

public perception to determinations of the linkages, if 

any, between residual trace organic compounds in 

treated wastewater effluents and impacts on the 

environment and human health.

Although implementation will take time, a clear punch 

list exists. As the agencies begin work, resulting 

progress in water conservation and reuse will benefit 

all the citizens of Arizona and stand as a tribute to the 

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dedication and intellect of the participants who 

contributed long hours to the BRP process.

References

ADEQ, Arizona Department of Environmental Quality Annual 

Report: Water Quality Report, Appendix iii, 1997.

ADHS, Arizona Department of Health Services, Engineering 

Bulletin No. 11: Minimum Requirements for Design, 

Submission of Plans and Specifications of Sewage Works, 

July 1978.

Arizona Administrative Code, A.A.C. Title 18, Ch. 9, Art. 6, 

R18-9-601 through 603

Arizona Administrative Code, A.A.C. Title 18, Ch. 11, Art. 3, 

R18-9-301 through 309

Arizona Administrative Code, A.A.C. Title 18, Ch. 9, Art. 7, 

R18-9-701 through 720

Arizona Administrative Code, A.A.C. Title 18, Ch. 9, Art. 2, 

Part B, R18-9-B201 through B206

Arizona Revised Statutes, A.R.S. 49-203(A)(6) 

Arizona Department of Water Resources. 2010. “Final 

Report of the Governor's Blue Ribbon Panel on Water 

Sustainability.” Retrieved on Spet. 7, 2012 from 

<http://www.azwater.gov/AzDWR/waterManagement/BlueRi

bbonPanel.htm>.

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2012 Guidelines for Water Reuse

Effluent Auction in Prescott Valley, Arizona

Author: Christopher Scott, PhD (University of Arizona)

US-AZ-Prescott Valley

Background 

Arizona and other areas of the Southwest are 

experiencing rapid growth in population and water 

demand (Eden and Megdal, 2006). Despite the 

economic and real estate downturn that began in 

2007, future demands for water and the resulting need 

for wastewater reclamation and reuse are expected to 

continue to grow (Scott et al., 2011), especially in 

Arizona’s urban corridor stretching from Flagstaff and 

Prescott in the north, through Phoenix, and to Tucson 

and Nogales in the south (Morrison Institute, 2008). 

This region has a semiarid to arid climate with warm, 

mostly dry winters, and hot summers. Rainfall primarily 

occurs in convective thunderstorms that characterize 

the North American monsoon. Surface waters are 

subject to increased climate change and variability, 

exerting ever-greater pressure on groundwater and 

effluent as sources of supply (e.g., Tucson Water, 

2008).

Arizona formed Active Management Areas (AMAs) 

under the Groundwater Management Act of 1980 in 

order to address long-term water sustainability and as 

a quid pro quo to secure federal funding for the Central 

Arizona Project aqueduct and canal system. Among 

other stipulations, the Act requires that assured water 

supply for 100 years be demonstrated for any new 

growth that is planned in the AMAs. In a process 

regulated by the Arizona Department of Water 

Resources (ADWR), jurisdictions have thus far 

exclusively relied on surface water or groundwater to 

meet assured water supply rules.

In a first-of-its-kind, in Arizona and the nation, the 

Town of Prescott Valley in 2006 made the case, in 

physical-hydrological terms and according to 

institutional and administrative rules, that effluent 

recharged into aquifers within town limits could be 

used to meet future water demands. As a result, in 

2007, Prescott Valley auctioned rights to its future 

effluent to the highest bidder, allowing real estate 

interests to continue development that could otherwise 

have been restricted due to water scarcity. The bidder 

would receive credits to extract groundwater to be 

used to satisfy the assured water supply requirement. 

Prescott Valley intended to use the proceeds to help 

pay its share of the costs of a pipeline to move water 

from the Big Chino ranch to Prescott and Prescott 

Valley, both part of the Prescott AMA. The prospect of 

receiving water in the future from this pipeline was 

deemed to be uncertain by ADWR in 2006, and 

therefore was disallowed as a source of assured water 

supply for Prescott Valley.

This case study describes the Prescott Valley effluent 

auction and demonstrates that a) specific institutional 

conditions were necessary to allow the effluent-rights 

transfer to occur, b) effluent is a marketable 

commodity that benefits a specific set of interests, and 

thus requires further scrutiny to ensure broader, 

beneficial outcomes, and c) policy choices favoring 

effluent for growth must consider environmental uses 

and in-stream flows. These observations have 

implications for water reuse within Arizona, across the 

Southwest, and beyond.

Effluent Auction: Water Resources and 

Regulatory Considerations 

Prescott Valley offered for auction the right to 2,724 

ac-ft (3.36 MCM) of effluent on an annual basis. By 

Arizona’s assured water supply rules, this would 

provide the buyer the right to use the effluent for 100 

years. The initial auction in 2006 failed, bringing only 

one bid that did not conform to the conditions 

established. Subsequently, the Town entered into an 

agreement with Nebraska-based Aqua Capital 

Management, which provided a floor-price guarantee 

at a pre-negotiated price of $19,500 per ac-ft 

($15.80/m3

). This left the Town the option to auction 

the effluent for a better price, but by doing so, it would 

pay a contract breakup penalty. In 2007, WestWater 

Research coordinated the auction, which brought in 

three bids. Water Asset Management through its 

subsidiary Water Property Investors, LLC offered the 

highest bid at $24,650/ac-ft ($19.98/m3

) for a total of 

$67 million. 

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There is extensive U.S. and international experience 

with marketing effluent pollution credits. However, the 

Prescott Valley case has set precedent in creating 

marketable rights for effluent as a commodity (Scott 

and Raschid-Sally, 2012). This was only possible with 

prior institutional and legal arrangements, briefly 

summarized here. 

Effluent from Growth, Effluent for 

Growth 

Effluent, and reclaimed water of other qualities suitable 

for a range of uses, is generated as a result of urban 

growth. Under conditions of water scarcity such as 

those in Arizona, effluent is viewed as a resource to 

meet growth-related water demands. This is 

increasingly the case in the context of regulatory limits 

on new surface water diversions and additional 

groundwater pumping. At the same time, climate 

change and variability, which water managers in the 

region address as “extended drought,” make effluent 

an integral part of water supply planning—an attractive 

alternative to conventional supplies.

Two features of the Prescott Valley case are especially 

interesting. First, the Town chose not to retain the 

rights to its effluent and instead used it as a financial 

mechanism to secure other, more conventional, water 

supplies from the Big Chino ranch. Second, the 

purchaser of the effluent, Water Property Investors, 

was not an Arizona developer but instead a holding 

company – essentially a speculator in effluent – that 

subsequently sold portions of the effluent rights it had 

purchased at auction. In 2009, developer John 

Crowley II of Denver, Colorado, purchased 200 ac-ft 

(0.25 MCM) and Cavan Real Estate Investments of 

Scottsdale, Arizona purchased 700 ac-ft (0.86 MCM) – 

both for undisclosed amounts price. These aspects of 

the effluent sale have important management and 

policy implications for water use, real estate growth, 

and environmental quality in Prescott Valley and more 

broadly. 

According to the town manager, the auction process 

that resulted in the transfer of water credits to 

developers heightened competition in water markets 

with resulting financial benefits for local residents. The 

water resources manager of Prescott Valley observed 

that: a) existing infrastructure and available effluent 

were necessary, b) effluent rights needed to be eligible 

under assured water supply rules, and c) partnering 

with the private sector was necessary in order to 

navigate water markets and to structure financial risks 

allowing the town to auction its effluent. 

Conclusions and Lessons Learned 

It appears inevitable that markets for effluent as a 

resource will expand. The Prescott Valley case is likely 

the first of many such transactions. Markets in effluent 

as a resource require regulatory oversight of the actual 

sale process and the transfer of water rights. In July 

2006 Prescott Valley was granted by ADWR, a 

Physical Availability Demonstration of 2,724 ac-ft (3.36 

MCM) of effluent (that meets water quality criteria) for 

100 years. In addition, Prescott Valley applied for a 

certificate to utilize the effluent on 14,000 ac (5670 ha) 

of land within the Prescott Valley Water District. This 

required a Notice of Intent to Serve, Verification of 

Construction Assurance, and evidence of financial 

capability. However, the environmental impacts of 

allocating effluent flows to real estate development 

were not required under the regulatory process. 

Effluent that is released to local streams plays an 

important role in sustaining riparian vegetation. In 

many instances, effluent is the primary source of water 

in streams that have been diverted for use in 

agriculture and urban areas. The quality of riparian 

vegetation is not simply a habitat and biodiversity 

issue—which are important in their own right; it also 

has implications for recreation, the attractiveness of 

local surroundings and indirectly for the value of real 

estate.

References

Eden, S., S. Megdal. 2006. Water and Growth, Chapter 4, 

pp. 63-101. 88th Arizona Town Hall Background Report. 

Morrison Institute. 2008. Megapolitan Sun Corridor. 

Retrieved on Sept. 7, 2012 from 

<http://morrisoninstitute.asu.edu/publicationsreports/Mega_AzSunCorr/view>.

Scott, C.A., A. Browning-Aiken, K.J. Ormerod, R.G. Varady, 

C.D. Mogollon, C. Tessmer. 2011. Guidance on Links 

between Water Reclamation and Reuse and Regional 

Growth. WateReuse Research Foundation Report 06-016-1. 

WateReuse Research Foundation, Arlington Virginia. 67 pp.

Scott, C.A., L. Raschid-Sally. 2012. The global 

commodification of wastewater. Water International 37(2): 

147–155.

Tucson Water. 2008. Water Plan: 2000-2050, 2008 Update.

D-19
2012 Guidelines for Water Reuse

Frito-Lay Process Water Recovery Treatment Plant, Casa 

Grande, Arizona

Author: Al Goodman, P.E. (CDM Smith)

US-AZ-Frito Lay

Project Background

PepsiCo and Frito-Lay, a key brand within PepsiCo, 

are proud to be reducing the effect of their operations 

on the environment. Since 1979, Frito-Lay has 

implemented conservation programs to shrink its 

overall environmental footprint as part of its snack food 

production. Frito-Lay’s manufacturing plant in Casa 

Grande, Arizona, makes snacks including corn and

potato products (Lay’s, Ruffles, Doritos, Tostitos, 

Fritos and SunChips). In the arid region of the 

southwest U.S., Frito-Lay completed a project with the 

ambitious goal to run the plant almost entirely on 

renewable energy and reclaimed water while 

producing nearly zero waste—something the company 

refers to as “Near Net Zero.” Major environmental 

projects implemented at the facility to achieve “Near 

Net Zero” included: process water recovery and reuse, 

use of renewable solar energy, generating steam from 

a renewable biomass boiler, and zero landfill waste 

projects.

Frito-Lay sought to integrate state-of-the-art 

technology and best practices from other Frito-Lay 

plants for a Process Water Recovery Treatment Plant 

(PWRTP). This PWRTP allowed the previous 

wastewater treatment system (which used land 

application of treated effluent) to be decommissioned, 

allowing those fields to be repurposed for solar energy 

production. The PWRTP system recycles up to 75 

percent of the facility’s process water—enabling FritoLay to reduce its water use by 100 million gallons 

(380,000 m3

Production at the facility is a 24 hours/day, 7 

days/week opeartion, requiring the PWRTP to be 

robust, reliable, and cost efficient. Design/build of the 

facility began in August 2009 with startup in June 

2010. 

) annually. An aerial view of the PWRTP is 

shown in Figure 1.

Capacity, Water Quality Standards, and 

Type of Reuse 

The average daily design flow of the PWRTP is 0.648 

mgd (28 L/s) from the production facility; 

characteristics of the influent are biochemical oxygen 

demand of 2,006 mg/L and total dissolved solids of 

2,468 mg/L. All sanitary wastes (i.e. bathroom 

connections) are segregated and discharged to the 

city sanitary sewer for conventional treatment at the 

City of Casa Grande Wastewater Treatment Plant.

The reuse quality established by Frito-Lay/PepsiCo 

required the water to meet EPA primary and 

secondary drinking water standards. The process 

water that is used to move and wash potatoes and 

corn, clean production equipment, and for other inplant cleaning and production needs, is reclaimed for 

reuse in the process. The reclaimed water quality from 

the PWRTP is of higher quality than the local potable 

water supply in terms of alkalinity, arsenic, and silica. 

A photo of the reclaimed water at various stages of the 

treatment process is shown in Figure 2. 

Figure 1

Aerial View of PWRTP (Photo credit: Frito-Lay)

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Treatment Technology 

The treatment train at the PWRTP is depicted in 

Figure 3. Oily wastewater (from specific production 

processes) is segregated to minimize adverse effects 

on the membrane bioreactor (MBR) and low pressure 

reverse osmosis (LPRO) processes; it is collected by 

separate drains and a free oil recovery sump. In 

addition, the plant recovers starch from specific 

production steps to recover resources for cost 

recovery and reduce nutrient loads on the PWRTP.

The treatment process includes: internal-feed rotary 

drum screening, equalization with pH adjustment using 

carbon dioxide, primary clarification/sedimentation, 

activated sludge with biological nutrient (nitrogen) 

removal in concentric steel bioreactor tanks, MBR, 

granular activated carbon (GAC), UV disinfection, 

LPRO, and chlorine disinfection prior to reuse. Treated 

water is stored in a 200,000 gallon storage tank. The 

GAC system was added in 2011 to enhance treatment 

for additional recovery and to further protect the LPRO 

membranes; the system uses lead-lag parallel carbon 

vessels. Reject water from the LPRO is discharged to 

the city of Casa Grande Wastewater Treatment Plant. 

Solids generated from the screening (corn and potato 

wastes) are collected and combined with the primary 

clarifier sludge for dewatering by centrifuge and is 

used as animal feed. The waste activated sludge is 

dewatered by a dedicated centrifuge and disposed by 

land application.

Providing MBR equipment outdoors, in pre-engineered 

vessels, using factory-mounted skids enabled faster 

installation and startup, helped control costs, and 

reduced ventilation challenges in the control building. 

The prepackaged GAC filters and LPRO membranes 

are housed in an isolated room with that are visible 

from the control room. A laboratory, conference room 

and offices are provided within an 8,000+ square foot 

control building and visitors center. All PWRTP 

systems are SCADA monitored and controlled.

Project Funding and Management 

Practices 

The project was fully funded by PepsiCo and Frito-Lay; 

project costs are confidential. A staff of six full-time 

operators is contracted by Frito-Lay to operate and 

maintain the PWRTP. 

Public Considerations 

Frito-Lay and PepsiCo have received the several state 

and national awards for this facility and include: 

WateReuse Association Small Plant Award (2011); 

Clean Water America Alliance U.S. Water Prize 

(2012); 2009 BE Inspired Award in the “Innovation in 

Water and Wastewater Treatment Plants” category, 

Plant-of-the-Year Award by Food Engineering

magazine.

In October 2009, Frito-Lay Casa Grande became the 

first snack food manufacturing facility to be certified 

LEED 2.0 Existing Building Gold in the company, the 

state of Arizona, and the United States. 

Successes and Lessons Learned 

The project provides better water quality than initially 

targeted by designers, and has enabled Frito-Lay to 

install 5 megawatts of solar photovoltaic and Sterling 

dish technology on land previously used for land 

application of treated wastewater effluent.

Figure 2

Water at Various Stages of the Treatment Process 

(Photo credit: Frito-Lay)

Figure 3

PWRTP process flow diagram

D-21
2012 Guidelines for Water Reuse

The Psychology of Water Reclamation and Reuse: Survey 

Findings and Research Roadmap

Brent M. Haddad, MBA, PhD (University of California, Santa Cruz) 

US-CA-Psychology

Project Background

The primary message of this report is the U.S. public is 

open to considering water reclamation and reuse for 

both potable and non-potable uses. Surveys were 

taken from 2695 respondents in five locations (San 

Diego, San Jose, Philadelphia, Oregon, and Phoenix) 

in 2006-2007. Surveys used the term “certified safe 

recycled water” as a term that would have meaning to 

the lay public although it does not correspond to any 

regulatory category of reclaimed water.

Survey Results

There were no significant regional or demographic 

differences in willingness to drink reclaimed water. 

And, other key findings included:

 Only 13 percent of respondents said they would 

be unwilling to drink certified safe recycled 

water.

 Roughly 26 percent of respondents do not 

believe that treatment systems can bring 

recycled water to a state of purity at which they 

would want to use the water. These 

respondents generally expressed a preference 

for natural treatment over technological 

treatment of water.

 Independent (e.g., university-affiliated) scientists 

are the most credible source of information on 

recycled water. State and federal government 

scientists are also credible. Hired actors, 

neighbors, and employees of private waterrelated companies are least credible. 

 30 percent of respondents are not interested in 

technical explanations of the water’s safety as 

long as they have credible and trustworthy 

assurances of its safety.

 Systems that include natural barriers such as 

groundwater recharge or reintroduction to a 

river are slightly more trustworthy compared to 

systems without these features.

 In the short run (long run was not tested), 

exposure to information about the safety of 

reclaimed water has an effect on willingness to 

use it, even those initially fully opposed to 

drinking certified safe recycled water. Both the 

approach of recycled water is safe and all water 

has the properties of recycled water (i.e., no 

such thing as pure or pristine water) were tested 

and each showed an increase in willingness to 

drink certified safe recycled water.

 Although the statistical relationships are often 

weak, the person most likely to reject certified 

safe recycled water has the following 

characteristics:

- Highly concerned about and easily 

disgusted by the presence of potential 

contagions in many settings (not just waterrelated)

- Self-identified as not politically moderate

- Less trusting in government institutions and 

science

- Less favorable toward technology in general

- Less impressed by successively more 

effective water treatment technologies

- More interested in knowing about the 

history of one’s drinking water

 Individuals most likely to accept and use 

certified safe recycled water have the following 

characteristics:

- They have been exposed to the idea that all 

water is used

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

- They have been exposed to statements 

about the purity of certified safe recycled 

water

- They are confident they will get used to 

drinking certified safe recycled water over 

time if it is introduced

 Reclaimed water intended for drinking is least 

likely to be rejected by individuals if it is:

- Certified safe by scientists 

- Extensively treated prior to use

- Used in some natural way (river, lake, 

groundwater replenishment) prior to it being 

directly reintroduced to the drinking water 

system

Future Research Needs 

The study identified research needs in the following 

areas:

 Fundamental research on human reactions to 

water quality, including demographic factors; 

psychological attributes; beliefs about 

hydrology, geology and water technology; and 

beliefs about natural systems and hybrid 

natural-engineered water treatment systems. 

Insights would inform agency-public 

communication strategies and regulatory 

reform.

 Research into modes of introduction of 

reclaimed water. Two approaches include slow, 

incremental introduction versus rapid, complete 

introduction. Each has general strengths and 

weaknesses when used in other contexts of 

introducing new technologies. Insights would 

inform how agencies introduce water reuse to 

their service territories.

 Research into opposition and opponents of 

water reuse. Insights could inform the public 

decision-making process and other modes of 

agency-public communication and decisionmaking that may be unnecessarily fueling the 

stridency of opposition.

 Research into the relationship between 

understanding water treatment technology and 

public acceptance of recycled water. How do 

images and statements about water treatment 

technology found in mailers, facility tours, public 

meetings, and websites influence the public? 

Results could help water agencies communicate 

with the public.

References

Haddad, B., Rozin, P., Slovic, P., and Nemeroff, C., 2010. 

The Psychology of Water Reclamation and Reuse: Survey 

Findings and Research Roadmap. Arlington, VA: 

WateReuse Foundation.

D-23
2012 Guidelines for Water Reuse

Managing a Reclaimed Water System through a Joint 

Powers Authority: San Ramon Valley

Author: David A. Requa, P.E. (Dublin San Ramon Services District)

US-CA-San Ramon

The Dublin San Ramon Services District (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 

California agencies have successfully used the joint 

powers model to plan a system that serves both newly 

built and retrofitted neighborhoods, to work through 

multiple phases of construction, and to coordinate 

distribution and customer service.

Project Background 

DSRSD and EBMUD have delivered potable water to 

adjacent communities since 1967. Although they rely 

on different water sources, both agencies face supply 

constraints in dry years; as a result, both agencies 

have long supported water recycling to increase 

reliability of potable water supplies. The DSRSD and 

EBMUD service areas and recycled water system are 

shown in Figure 1. 

In the early 1990’s DSRSD agreed to provide water for 

major new developments approved by the two cities in 

its service area. Its water service plans were 

predicated upon requiring customers to use reclaimed 

water to irrigate large landscapes. DSRSD had an 

available supply of secondary effluent from its own 

wastewater treatment plant, and in 1993 obtained a 

state permit to distribute reclaimed water. EBMUD had 

developed reclaimed water projects in other parts of its 

service area, but in the San Ramon Valley it lacked a 

local source of effluent. A reclaimed water partnership 

was a cost-effective solution for both agencies. As a 

much larger agency, EBMUD also could provide the 

financial and political base to support the program and 

better obtain grant funding.

Figure 1

San Ramon Valley reclaimed water system (March 2010)

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Management Practices

In 1995, the two agencies formed the DSRSD-EBMUD 

Reclaimed Water Authority (DERWA) to plan, build 

and operate the new program. DERWA is a wholesale 

entity with two retail customers—EBMUD and DSRSD. 

It is governed by a four-member Board of Directors 

comprised of two board members from each partner. 

Day-to-day operations are handled by an authority 

manager, who is a part-time contract employee.

The program is designed to ultimately deliver 6,420 

ac-ft/yr (7.9 MCM/yr)—3,730 ac-ft/yr (4.6 MCM/yr) to 

DSRSD customers and 2,690 ac-ft/yr (3.3 MCM/yr) to 

EBMUD customers (DERWA 2003). The DERWA 

system consists of a sand filtration/UV disinfection 

(SFUV) treatment facility, a microfiltration/UV 

disinfection (MFUV) system used as backup and 

during the winter, three pump stations, two reservoirs, 

and 16 miles (26 km) of main transmission pipeline.

EBMUD and DSRSD designed and constructed the 

parts of the system to operate with minimal DERWA 

staffing (one part-time administrator to assist the 

authority manager). Ownership and labor are divided 

as follows: 

 DSRSD owns the treatment plant and an initial 

high-lift pumping station at the plant. 

 DERWA owns two pumping stations, two 

reservoirs, and the backbone transmission 

pipelines.

 Under contract to DERWA, DSRSD operates 

and maintains the entire system.

 EBMUD provides the DERWA treasurer and 

manages financial matters.

 Each agency owns and operates its distribution 

system and interacts with its own customers.

Funding 

DSRSD and EBMUD divided $82 million dollars in 

DERWA capital costs based upon the benefit received 

from each facility or reach of pipeline. The resulting 

cost-share—52 percent DSRSD and 48 percent 

EBMUD—also was applied to grants and loans that 

DERWA obtained to build joint-use facilities (DSRSD, 

2011b). These included $5 million in grants from the 

California State Water Resources Control Board 

(SWRCB), $14.5 million in grants from the U.S. Army 

Corps of Engineers, and $25 million in SWRCB lowinterest loans. EBMUD and DSRSD provided 

remaining funding from internal sources. DERWA 

divides the annual cost of operation between DSRSD 

and EBMUD in proportion to the amount of reclaimed 

water delivered by each agency during the year. 

The backbone of the system was completed in stages, 

from 1998 to 2010. DSRSD’s initial customers were 

located in newly developed areas, where reclaimed 

water use is mandated by ordinance. DSRSD is 

building its reclaimed water distribution systems at the 

same time as other infrastructure in those areas 

develop. EBMUD has the more difficult task of 

connecting existing customers to its reclaimed water 

distribution system. In addition to managing complex 

infill construction, EBMUD must work with customers 

to retrofit their irrigation systems.

Water Quality and Treatment 

Technology 

In 2010, the partnership produced 2,174 ac-ft (2.68 

MCM) of reclaimed water that meets California Title 22 

standards for unrestricted non-potable reuse (DSRSD, 

2011c). When irrigation demand is high, SFUV 

facilities produce up to 9.7 mgd (425 L/s); during the 

winter, MFUV is typically used to produce smaller, 

intermittent deliveries up to 3 mgd (131 L/s). The 

redundant treatment systems increase reliability and 

operational flexibility. The two systems may also be 

operated in parallel to produce up to 12.7 mgd (556 

L/s). A planned future expansion will increase the 

SFUV capacity to 16.5 mgd and the total treatment 

capacity to 19.5 mgd (854 L/s) (DSRSD, 2011a).

Institutional/Cultural Considerations 

EBMUD has close to 2,000 employees and DSRSD 

about 110. The partners have had to overcome 

differences in size and corporate culture to 

communicate efficiently with each other and their 

customers. For example, as operations began in 2006, 

small bits of plastic debris began clogging sprinklers 

and meters. DSRSD and EBMUD field crews 

responded to their customers and began looking for 

causes, but in the early stages they did not discuss the 

problem with each other. The problem was eventually 

traced to dime-sized plastic produce labels passing 

through the SFUV system. Both agencies realized they 

could have provided better customer service by 

comparing notes earlier during the troubleshooting 

process (Requa et al,, 2008).

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Similarly, DSRSD failed to notify EBMUD when the 

reclaimed water plant went offline after a series of 

process upsets in 2007. DSRSD staff assessed the 

quantity of water in storage and struggled for many 

hours to resume reclaimed water production before 

deciding to add potable water to the distribution 

system. However, a major EBMUD customer ran out 

of water, and EBMUD was unaware of the production 

problem until contacted by a customer (Requa et. al., 

2008).

The partners have since jointly developed and agreed 

to processes to improve communications and 

coordinate responses. In the second year of operation, 

they also began conducting an annual 

communications roundtable to walk through potential 

incidents such as cross-connections, pressure 

problems, and water quality concerns. These 

roundtables bring together a cross-section of staff from 

each agency. Simply getting to know each other has 

helped to foster a team culture. 

Successes and Lessons Learned

The partners also have found ways to leverage their 

differences. For example, it was a challenge to 

standardize automated meter reading (AMR) devices. 

EBMUD had a pilot AMR study in progress and 

decided to also evaluate DSRSD’s device. Since 

DSRSD had meters in stock, its employees installed 

them for EBMUD, avoiding lengthy procurement and 

training delays. DSRSD crews also installed isolation 

couplings on both DSRSD and EBMUD connections to 

the DERWA backbone. The couplings protect field 

staff from stray current from overhead electrical lines. 

Because DSRSD operates the DERWA system, its 

staff was already trained in how to avoid shocks while 

working on DERWA pipelines and could install the 

needed protection more quickly (Requa et. al., 2008). 

Using a joint powers authority to develop reclaimed 

water service has benefited both partners. They share 

construction and operations costs and are maximizing 

the beneficial reuse of the only source of effluent in the 

area. Because the distribution systems are completely 

integrated, the two agencies must communicate about 

water quality and customer service on almost a weekly 

basis. Unexpected operational issues always occur in 

a new enterprise. Partners must work as a team to 

successfully operate a joint system.

References

DSRSD•EBMUD Reclaimed Water Authority. 2003. 

Agreement for the Sale of Reclaimed Water by the 

DSRSD•EBMUD Reclaimed Water Authority to the Dublin 

San Ramon Services District and the East Bay Municipal 

Utility District. Dublin, California.

Dublin San Ramon Services District. 2011a. 2010 Urban 

Water Management Plan. Dublin, California.

Dublin San Ramon Services District. 2011b. DERWA 

Budget, Fiscal Year 2011-2012. Dublin, California.

Dublin San Ramon Services District. 2011c. DERWA Report 

of Operations, January-December 2010. Dublin, California.

Requa, David, Dan Gallagher, and Linda Hu. 2008. “Startup 

Challenges of a Joint Agency Reclaimed Water System.” 

2008 WateReuse California Annual Conference 

Proceedings. Newport Beach, California. March 24-26, 2008.

D-26
2012 Guidelines for Water Reuse

City of San Diego – Water Purification Demonstration 

Project

Authors: Marsi A. Steirer; Amy Dorman, P.E.; Anthony Van; and Joseph Quicho 

(City of San Diego Public Utilities Department)

US-CA-San Diego

Project Background or Rationale 

The City of San Diego is the eighth largest city in the 

United States and delivers an annual average of 210 

mgd (9200 L/s) to 1.3 million people in a water service 

area of 404 square miles (1,046 km2

). With 

approximately 10 inches of rain a year, nearly 85 

percent of San Diego’s water supply is imported from 

the Colorado River and the California State Water 

Project. In the past, importing water from the Colorado 

River and Northern California has been a low-cost, 

dependable water supply option, but in recent years, 

these sources have become less reliable and more 

expensive. Additionally, the cost of imported water has 

increased by 85 percent in the last eight years and is 

expected to double by 2020. These conditions have 

intensified the need to identify new, locally controlled 

water sources.

San Diego has had an active water conservation 

program since the mid-1980s, and has been recycling 

water for irrigation and industrial use since the late 

1990s. While this has helped reduce dependence on 

imported water, non-potable reclaimed water use is 

seasonal, does not provide relief the entire year, and 

requires a separate distribution infrastructure to be 

operated and maintained. In 2004, the city embarked 

on its Water Reuse Program with the goal of 

maximizing water recycling, either through a nonpotable market expansion, potable reuse, or a 

combination of these practices. The Water Reuse 

Study was the first phase of the Water Reuse Program 

and was completed in 2006; indirect potable reuse 

through reservoir augmentation was identified as the 

preferred strategy. This case study focuses on the 

second phase of the Water Reuse Program, the Water 

Purification Demonstration Project (Demonstration 

Project), which will conclude in early 2013.

Type of Reuse Application and 

Capacity

The Demonstration Project will evaluate 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. This multiple barrier concept is depicted in 

Figure 1. If this concept for developing a new local 

supply proves viable, Phase 3 of the Water Reuse 

Program would implement a full-scale facility.

As part of the Demonstration Project, the city is testing 

and operating a 1 mgd (44 L/s) demonstration-scale 

Advanced Water Purification (AWP) Facility at the 

North City Water Reclamation Plant (North City). It is 

using the tertiary-treated water from North City as feed 

and is producing purified water of distilled water 

quality. Water quality is being monitored across the 

entire purification process to determine the 

effectiveness of the process and to ensure that all 

systems are functioning properly. Ultimately, the city 

will be able to determine if the purified water meets all 

drinking water standards and can be put in the San 

Vicente Reservoir; test water will not be placed in San 

Vicente Reservoir during the demonstration phase. 

Additionally, an independent advisory panel (IAP) of 

experts has been convened to provide the technical 

oversight and input throughout the demonstration 

process.

A limnology study of the San Vicente Reservoir is 

being conducted to establish minimum residence time, 

water quality, and other regulatory requirements. The 

dam is currently being raised to nearly triple the 

reservoir’s storage capacity. The primary tool for this 

study is a three-dimensional computer model of the 

enlarged reservoir, which has been calibrated, 

reviewed by an IAP, and validated for use on this 

project.

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

As of 2012, regulatory requirements for Indirect 

Potable Reuse through reservoir augmentation have 

not been defined in California. Thus, defining such 

requirements is a key component of this demonstration 

project, and the city has engaged both the California 

Department of Public Health (CDPH) and Regional 

Water Quality Control Board (RWQCB). The State’s 

draft guidelines for groundwater recharge systems are 

being referenced for the advanced water treatment 

performance criteria. 

Treatment Technology and Water 

Quality Parameters 

The AWP Facility is equipped with microfiltration (MF) 

and ultrafiltration membranes, reverse osmosis, and 

advanced oxidation (ultraviolet and hydrogen 

peroxide); the demonstration system incorporates 

membranes of the same size, specification, and 

configuration as those that would be utilized for a fullscale facility. Demonstration testing is being conducted 

over a 12-month period and in accordance with the 

Testing and Monitoring Plan that incorporated review 

comments from the IAP, CDPH, and RWQCB. 

Monitoring of several water quality parameters in the 

Testing and Monitoring Plan include, but not limited to 

the following:

 Contaminants regulated by the Safe Drinking 

Water Act or California State regulations

 Disinfection by-products and trace constituents

 Nutrients that may lead to eutrophication of San 

Vicente Reservoir

 Specific contaminants and surrogates that 

effectively monitor integrity of each unit process

Figure 1 

Water Purification Demonstration Process

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

 Local constituents of concern, endocrine 

disrupting compounds, pharmaceuticals, and 

personal care products

Project Funding and Management 

Practices 

In 2008, the San Diego City Council approved a 

temporary water rate increase to fund the project. The 

Water Purification Demonstration Project has a budget 

of $11.8 million with federal and state grants providing 

up to $4 million in assistance. In addition to the AWP 

Facility and reservoir study, the project also includes 

public outreach, energy and economic analysis, and 

an alignment study for the 23-mile (37-km) purified 

water pipeline to San Vicente Reservoir.

Institutional/Cultural Considerations 

The indirect potable reuse concept was first introduced 

to the community in the mid-1990s. There was 

negative public reaction at the time that continued well 

into the next decade. Some dubbed it, “toilet to tap.” 

However, comprehensive education efforts about the 

need for conservation, increasing calls for water 

supply diversification and increased awareness of the 

region’s existing raw water supply sources, have all 

helped turn the tide. In January 2011 and editorial in 

the local paper stated, “...this water would likely be the 

purest and safest water in the system.”

To build upon the growing awareness of the need for 

local supplies, a comprehensive public outreach 

program was launched as part of the Demonstration 

Project. Through the program substantial collateral 

material has been produced, a project website was 

created, e-updates and e-newsletters are sent out 

regularly to a growing interested parties list, and over 

100 project presentations have been given to 

community and business groups, especially those of 

underserved communities, throughout the city. These 

efforts will continue through the duration of the project. 

With the completion of the AWP Facility, facility tours 

are being offered to the public.

Successes and Lessons Learned

While the project is ongoing there have been two 

interim successes that can be highlighted. One 

success is the regulatory agencies involvement and 

cooperation. Both CDPH and RWQCB have been 

willing to attend and engage in project workshops on 

approximately a quarterly basis and provided 

comments to Demonstration Project reports.

Another success is that public outreach and education 

program efforts appear to be effective. There has been 

a recent shift in perception regarding purified water 

within the media and the community. The 

Demonstration Project received positive coverage both 

locally and nationally in early July 2011. It is not just 

the media who are coming to accept water purification 

as a viable option for San Diego. Public opinion polls 

show that strong opposition to indirect potable reuse 

dropped from 45 percent in 2004, to 12 percent in 

2009, and to 11 percent in 2011 (SDCWA, 2011). The 

same 2011 study by the San Diego County Water 

Authority found that 65 percent of respondents 

somewhat or strongly favor adding purified water to 

the drinking water supply and 77 percent of 

respondents informed about the Demonstration Project 

either strongly favor or somewhat favor the goals of 

the Demonstration Project.

With continued regulatory involvement and public 

outreach and education efforts the Demonstration 

Project is on the path for gaining regulatory approval 

and public acceptance. If the concept of using purified 

water to augment local reservoir supplies is deemed 

viable by the mayor, the city council, and the 

regulators, the city would implement it on a large 

scale. Full-scale facilities could produce up to 15 mgd 

(660 L/s) of purified water.

References

City of San Diego Water Reuse Study Final Draft Report. 

2006, prepared by PBS&J for the City of San Diego. 

<http://www.sandiego.gov/water/waterreuse/waterreusestud

y/news/fd2006.shtml>.

City of San Diego Public Utilities Department – Water 

Purification Demonstration Project website. 2011. 

<http://www.sandiego.gov/water/waterreuse/demo/>. 

San Diego Water Authority (SDCWA). 2011. Public Opinion 

Research. Retrieved on Sept. 7, 2012 from 

<www.sdcwa.org/public-opinion-research>.

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2012 Guidelines for Water Reuse

Groundwater Replenishment System,

Orange County, California

Authors: Mike Markus, P.E., D.WRE; Mehul Patel, P.E.; William Dunivin (Orange County 

Water District)

US-CA-Orange County

Project Background and Rationale 

For decades, semi-arid Orange County, Calif., has 

depended on Northern California and the Colorado 

River for much of its drinking water. However, with 

multi-year droughts and environmental constraints, 

imported water is becoming more expensive and less 

available. Population studies indicate that California 

could increase by 15 million people by 2020; Southern 

California alone could grow by 7 million and Orange 

County by 300,000. As new water supplies are sought, 

water recycling plays an important and key role.

In the 1990s, the Orange County Water District 

(OCWD) and Orange County Sanitation District 

(OCSD) joined efforts to provide a reliable water 

supply by developing a water purification program 

called the Groundwater Replenishment System 

(GWRS), which came on-line in January 2008. Prior to 

the GWRS, OCWD operated Water Factory 21 (WF21), a first-of-its-kind water treatment facility that 

produced 15 mgd (960 L/s) for a seawater intrusion 

barrier, from 1976 through 2004.

Using up to two-thirds less energy than it would take to 

import water from Northern California, and three times 

less energy than ocean desalination, the GWRS 

currently produces enough water for nearly 600,000 

residents, while saving enough energy to power 

21,000 homes each year. Additional benefits include 

eliminating the need for another ocean outfall and 

increasing “water diversity” in an arid region.

Capacity and Type of Reuse 

Application 

The GWRS is the largest advanced water purification 

facility of its kind, capable of producing 70 mgd (3070 

L/s) for indirect potable reuse (IPR). This revolutionary 

and innovative system removes pharmaceuticals, 

pesticides and other harmful contaminants before it is 

pumped to recharge basins, where it naturally filters 

into the groundwater basin, replenishing scarce 

drinking water supplies. The heart of the GWRS is the 

Advanced Water Treatment Facility (AWPF) facility, 

which includes microfiltration, reverse osmosis, and 

advanced oxidation processes, which consist of 

ultraviolet and hydrogen peroxide (Figures 1, 2 and 

3). The plant may be upsized in the future to produce 

130 mgd (5,700 L/s). 

Figure 1

GWRS microfiltration system (Photo Credit: Gina 

DePinto) 

Figure 2

GWRS reverse osmosis trains (Photo Credit: Gina 

DePinto) 

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Appendix D | U.S. Case Studies

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Water Quality and Treatment 

Technology 

During startup of the AWPF, monitoring water quality 

was an important component of the permit issued by 

the Regional Water Quality Control Board (RWQCB), 

in conjunction with the California Department of Public 

Health (CDPH). During acceptance testing of the 

AWPF, specific water quality tests were required.

Water quality monitoring is a fundamental component 

of ongoing GWRS operations. During the first two 

years of operation (2008-2009), 

concentrations of metals (e.g., 

aluminum and chromium), organic 

contaminants (e.g., 

trichloroethylene, NDMA, and 1,4-

dioxane), nutrients (nitrogen and 

phosphorous), and microbial 

indicators were all either nondetectable or well below state and 

federal drinking water quality 

limits. Similarly, unregulated 

chemicals such as pharmaceuticals 

and personal care products (e.g., 

ibuprofen, bisphenol-A) and 

endocrine disrupters (e.g., 

hormones) were consistently nondetectable in 2008, at parts per 

trillion concentrations. Nearly 

identical results were found in 

2009, with two isolated detections 

(e.g., caffeine) occurring at 

concentrations below available 

health screening guidelines. 

The GWRS water quality data is reported quarterly 

and formally documented in an annual report to state 

regulators. The GWRS is also reviewed annually by an 

Independent Scientific Advisory Panel of experts 

appointed by the National Water Research Institute 

(NWRI). 

Project Funding and Management 

Practices 

The GWRS capital cost was $480.9 million. OCWD 

received $92 million in grants from state and federal 

agencies and a $196 million contribution from 

OCSD. OCWD used a combination of long-term debt 

and state loans to fund the remaining capital cost, 

which has an annual debt service of $11.5 million. The 

debt service and cost to operate the GWRS is covered 

by OCWD’s general fund. The annual operating 

budget (excluding debt service) is about $28.5 million, 

which includes electricity, chemicals, labor and 

maintenance. The project receives an annual 

operational subsidy of approximately $7.5 million for 

12 years from the Metropolitan Water District of 

Southern California for reducing demand on the state’s 

imported water supplies.

OCWD receives revenue primarily from three sources: 

the replenishment assessment paid by retail agencies 

for pumping groundwater, a 

percentage of local property 

taxes, and investment income. 

The assessment is currently 

$249/ac-ft ($0.20/m3

), which is 

well below the cost of imported 

water supplies that start at 

$750/ac-ft ($0.61/m3

). To 

replenish the groundwater 

basin, OCWD uses a 

combination of flows from the 

Santa Ana River, GWRS water 

and imported water. The cost 

of GWRS water is less than 

treated imported water and is 

the highest quality, droughtproof and reliable source of 

water available. Imported 

water supplies, especially 

untreated or raw water 

supplies, can be interruptible 

and available for purchase 

only when a surplus exists. 

Institutional/Cultural Considerations 

The GWRS program is a direct result of a mutually 

beneficial partnership between OCWD and OCSD, 

cultivated over nearly 40 years, beginning with WF-21 

in the 1970s. In the mid-1990s, OCSD faced the 

possibility of building a second ocean outfall at a cost 

of $200 million. At the same time, OCWD was dealing 

with problems of seawater intrusion and the need to 

expand WF-21 from 15 to 35 mgd (920 to 1530 L/s). 

Joining efforts in 1997, OCSD agreed to supply 

OCWD with 96 mgd (4200 L/s) of secondary treated 

wastewater at no cost. OCSD committed to 

maintaining a stringent source control program to keep 

potentially harmful contaminants out of the treated 

wastewater before it was supplied to the GWRS. 

OCSD and OCWD also agreed to share the $481 

Figure 3

GWRS ultraviolet reactor system (Photo 

Credit: Gina DePinto)

D-31
Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

million cost to construct the GWRS. Approving the 

GWRS was a significant and risky step for its Boards 

of Directors because, at the time, IPR had been 

politicized and suffered major defeat in San Diego. 

Coordinating two Boards and gaining support was 

challenging. One month after signing a cooperative 

agreement to plan and construct the GWRS, OCWD 

and OCSD established the GWRS Steering 

Committee to oversee planning, design and 

construction in cooperation with each agency’s 

governing board. The committee made decisions and 

approved expenditures, while OCWD led engineering, 

construction, operations and outreach with OCSD’s 

engineers and Public Affairs. Today, communication 

between the staffs is excellent and the Steering 

Committee is still intact to work through ongoing 

operational issues. 

One of the most important measures OCWD uses to 

evaluate success is public acceptance of IPR. An 

aggressive outreach program was established to 

educate and secure support from local, state and 

federal policymakers, business and civic leaders, 

health experts, environmental advocates and 

academia. Because of the negative and misinformed 

public perception of purifying wastewater to drinking 

water, the agencies decided that the “clean water” 

agency should be out front to manage day-to-day 

management of the outreach campaign. 

To brand the safety, purity and high quality of water, 

OCWD staff led outreach and interfaced with 

consumer media, while OCSD staff served as advisors 

on outreach decisions and helped manage trade 

media relations. The team made more than 1,200 

presentations from 1999 to 2007, secured thousands 

of media impressions, and garnered more than 600 

letters of support including those from all 21 city 

councils, the district’s senators and congressional 

representatives, local state assembly members, state 

senators, the governor, and the Orange County Board 

of Supervisors. Agencies that govern or influence 

water policy were also supportive including the 

Department of Water Resources, CDPH and the Santa 

Ana RWQCB.

Without such strong support from policymakers, the 

project may not have moved forward, nor would 

OCWD have been able to secure $92 million in state, 

federal and local grants to help fund the project. The 

Metropolitan Water District of Southern California also 

awarded GWRS an $85 million operational subsidy for 

reducing dependence on the state’s imported water 

supplies. 

As public support grew, a comprehensive supporter list 

was developed, and eventually the Boards formed a 

committee of respected community opinion leaders 

and experts that served as project spokespeople. In 

preparation of the initial expansion to 100 mgd (4381 

L/s), the agencies are mindful that opposition is still a 

threat, and so the outreach effort continues. OCWD 

continues to make presentations to business and civic 

groups and at conferences, employs social media, and 

conducts tours of the GWRS. In 2010, about 4,000 

visitors toured the facility. Many were elected officials 

and water experts from across the United States, 

Africa, Australia, China, Japan, Korea, Spain, Italy, 

Germany and Israel. To date, there has been no 

organized or significant public opposition to the GWRS 

and the outreach initiative is touted as one of the key 

reasons for the project’s success.

Successes and Lessons Learned

OCWD and OCSD successfully partnered to build a 

potentially controversial water project that garnered 

overwhelming public support and overcame a “toiletto-tap” misperception. The GWRS has revolutionized 

how consumers look at wastewater—as another 

resource they should take care of and reuse. 

The partnership between OCWD and OCSD has 

become an international model for water recycling 

recognized globally with numerous awards, including 

the prestigious Stockholm 2008 Industry Water Award, 

Säid Khoury Award for Engineering Construction 

Excellence and the American Society of Civil 

Engineers Outstanding Civil Engineering Achievement. 

Municipalities across California, the United States, and 

Australia are planning similar projects, and the citystate of Singapore modeled a smaller scale IPR 

project after the GWRS. By developing a project that 

puts recycled water into the drinking water supply, 

OCWD is paving the way for others to gain public 

acceptance of this environmentally-friendly and safe 

practice.

D-32
2012 Guidelines for Water Reuse

EDR at North City Water Reclamation Plant

Authors: Eugene Reahl and Patrick Girvin (GE)

US-CA-North City

Project Background

The city of San Diego, Calif., shares a problem 

common with many other western cities—meeting the 

ever-increasing challenge of developing adequate 

drinking water supplies to satisfy regional 

development. Unfortunately, new sources of fresh 

water are not readily available without large capital 

expenditures. As a result, in the late 1990s, San Diego 

took a major step in helping to solve this problem by 

equipping the brand new North City Reclamation Plant 

with an electrodialysis reversal (EDR) system. The 

EDR system could desalinate tertiary treated 

wastewater to provide a new source of high quality 

irrigation water, thereby reducing demand on the fresh 

water supply. 

Treated wastewater effluent that supplies the 

reclamation facility has salinity levels up to 1,300 mg/L 

TDS during the summer and early fall. In order to use 

this water for golf courses, plant nurseries, parks, 

highway green belts, and irrigation water for common 

areas in homeowner associations, the treated water 

needed to have a water quality of less than 1,000 mg/L

TDS with low sodium levels. EDR was able to achieve 

the required removals and also allow for blending of a 

stream of raw water with the feed, increasing total 

volume of reuse water produced.

Treatment Process and Capacity 

The EDR system operates at 85 percent recovery of 

the treated flow, compared to 80 percent offered by a 

more conventional microfiltration-reverse osmosis 

(MF-RO) system, which was originally evaluated as an 

alternative to the existing system. Another added 

benefit of the EDR system is a reduction in use of 

chemicals compared to other technologies for reducing 

TDS concentrations. The EDR runs with no chemicals 

added to the feed stream; although, chlorine is added 

to the concentrate recirculation loop of the EDR to help 

prevent biological growth. The EDR membranes are 

not sensitive to chlorine and can tolerate brine 

residuals, reducing frequency of cleaning.

When the reclamation plant was originally installed in 

1998, the capacity of the EDR system was 2.2 mgd 

(96 L/s). Since this initial installation, the facility has 

undergone 4 expansions. In 2011, the EDR capacity at 

the plant could produce 6.6 mgd (290 L/s) as shown in 

Figure 1. This treated water is blended with treated 

wastewater effluent to provide up to 15 mgd (660 L/s) 

of total blended reclaimed water flow.

San Diego used an existing 47-mile (75 km) pipeline to 

deliver high quality reclaimed water to local customers. 

This challenge of this strategy was to sell this water as 

an attractive alternative to using hard-to-replace fresh 

drinking water in non-potable applications such as 

irrigation. But, after successful implementation, the 

end result has been a reduction in use of potable 

water for these applications, conserving that precious 

supply for potable water uses.

Project Funding and Management 

Practices 

Over the years, the facility has been expanded several 

times. For most of these projects, the city has provided 

their own funding for the expansion to their facility; 

however, addition of the 6th unit was partially funded 

through the Bureau of Reclamation.

Figure 1

North City WRP with 6th EDR unit installed

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Successes and Lessons Learned

The plant has successfully operated for over 10 years. 

Much of the plant’s success may be attributed to the 

excellent operation and maintenance of the 

equipment. The EDR system utilizes liquid sodium 

hypochlorite addition to minimize biogrowth, and 

regular cleanings help maintain optimum membrane 

performance.

Due to the variable quality of the feed water to the 

facility, the EDR’s ability to handle higher organic 

loading, up to 15 mg/L of total organic carbon was an 

important factor in keeping the facility running. The 

system could accept the higher levels without any 

negative impact on the product water conductivity. 

This produced a consistent product to the City’s 

customers as shown in Figure 2. 

References

Reahl, Eugene. 2004. San Diego Uses EDR Technology for 

Desalination, GE Water & Process Technologies.

Figure 2

Performance of North City EDR system

D-34
2012 Guidelines for Water Reuse

Water Reuse Study at the University of California Santa 

Cruz Campus

Author: Tracy A. Clinton, P.E. (Carollo Engineers)

US-CA-Santa Cruz

Project Background

In response to the master plan for higher education, 

the president of University of California (UC) asked UC 

campuses to consider enrollment growth. For UC 

Santa Cruz (UCSC), this request corresponded to a 25 

percent increase in student population. Already faced 

with severe water supply shortages and limited to no 

possibilities for increases, UCSC decided to increase 

self-reliance and sustainability of campus water 

resources, and define measures for utilization of 

recycled water. These goals were to be achieved while 

considering challenges such as seasonal population 

fluctuations of the UCSC campus, city water supply 

limitations, campus elevation gradients, and the future 

challenge of UCSC population growth. Although 

campus water demand was expected to grow from 200

million gallons per year (MGY) (760,000 MCM/yr) in 

2009 to 400 MGY (1.5 MCM/yr) in 2020, the city of 

Santa Cruz had previously reported that there was 

little to no increase in water supply available to UCSC. 

In response, the campus began addressing challenges 

by developing a decision analysis framework to enable 

the selection and ranking of a range of potential reuse 

projects that could be implemented both immediately, 

and in response to future potable water and/or energy

reduction requirements. 

Capacity and Type of Reuse 

Application 

Approximately one-half of the allocation of total 

campus water consumption included non-potable uses 

(Table 1) that could be offset by using alternate 

sources (Maddaus, 2007). In addition, roughly 97 MGY 

(0.37 MCM/yr) could be offset with recycled water, 

rainwater, graywater, and well water, which are 

available in sufficient volumes (Table 2). Both the 

demand and the alternate water supplies have 

seasonal dependencies that must be considered. For 

example, water use is highest when classes are in 

session and lowest during summer and between 

quarters. The reuse opportunities that UCSC

considered were ones that minimize energy 

consumption, maximize sustainability, and where 

seasonal and spatial dependence considering varying 

campus elevations of sources and demands for nonpotable water are aligned. 

Table 1 Summary of non-potable water demands

Demand

Volume 

Required 

(MGY)

Seasonal 

Dependence

Toilet Flushing 6.3 Dependent on student 

populations

Irrigation 291 Dependent on weather

Cooling Towers 82 Dependent on student populations and 

weather 1 Volume for irrigation by the top 10 users; submetered 

irrigation demand on campus is 40 MGY

2 Includes volume required at new cooling tower location

Table 2 Summary of alternate water supplies available 

for non-potable use

Demand

Volume 

Required 

(MGY)

Seasonal 

Dependence

Rainwater 8.3 Dependent on weather

Graywater 13.8 Dependent on student 

populations

Recycled 1571 Dependent on student 

populations

Well 56.5 Not seasonally 

dependent 1 Represents entire campus wastewater flow

The lower area of campus, which includes 

administration offices and faculty housing, has an

elevation of 426 feet and receives about 30 inches (76 

cm) of rain annually. The upper area of campus, with 

an elevation of 982 feet (300 m) and about 48 inches 

(122 cm) of annual rainfall, includes residences and 

academic buildings. The middle area of the campus is 

open space and agricultural land. Peak rainfall occurs 

in January with little to no rain in the summer months 

of June through September. Rainwater is currently 

collected and systematically conveyed from the

campus to minimize erosion. Figure 1 shows the 

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

existing non-potable supplies and 

demands by general campus 

location/elevation. Options for replacing 

potable water demands were identified and 

grouped with respect to implementability 

into immediate, near-term, or long-term 

projects. 

Water Quality Standards and 

Treatment Technology 

The regulatory requirements defined for 

reuse of non-potable sources are outlined 

in Table 3.

Project Management Practices 

A “Model College” was developed as a 

planning tool. This model considers nonpotable supplies and demands assuming 

100 beds (i.e., residential component only). 

This model can be used by the campus to 

analyze future proposed reuse projects 

regarding demands relative to non-potable 

water supplies, sustainability, and energy 

use. UCSC now has tools to move 

aggressively to offset the increased water 

demand that will accompany its growth. 

The campus potentially has more supply of 

non-potable water than demand for it, so 

factors other than maximizing supply can 

be figured into project selection. For 

example, future project selection criteria 

include cost per gallon of non-potable 

water, construction cost of specific 

projects, volume of potable water offset, 

components of sustainability (mainly 

environmental impacts), educational value, 

and ease of operations of the project. 

The cost of implementing a reuse project is 

largely driven by the storage volume required for it, 

thus matching the seasonality of supply and demand 

(such as using rainwater for toilet flushing instead of 

irrigation) helps in reducing the cost of reuse projects. 

Another driver of cost is the proximity of supplies and 

demands because of energy requirements for 

pumping, particularly on this campus, which has over 

550 ft (168 m) elevation difference between the upper 

and lower campus areas.

Institutional/Cultural Considerations 

The UC released a Policy on Sustainable Practices in 

May 2007 which provided guidelines to all the UC 

campuses to: Incorporate the principles of energy 

efficiency and sustainability in all capital projects, 

renovation projects, operations and maintenance 

within budgetary constraints and programmatic 

requirements. The current version of the Policy 

requires LEEDTM Silver certification for new UC 

construction and existing renovations. 

Figure 1

Existing non-potable supplies and demands on UC campus

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Table 3 Requirements for reuse depending on source water

Source Possible Reuse Applications

Appendix G 

Graywater 

Guidelines

Title 22 Reuse 

Guidelines

Campus 

Plumbing Codes 

and Ordinances

Rainwater Irrigation, Toilet Flushing, HVAC 

processes

X 

Graywater1 Subsurface Irrigation X X 

Additionally Treated 

Graywater2 Irrigation, Toilet Flushing, HVAC processes

X X 

Tertiary Treated/Disinfected 

Wastewater3 Irrigation, Toilet Flushing, HVAC processes

X X 

Well Water Irrigation, Toilet Flushing, HVAC 

processes

X 

1 Treated and applied as outlined in the California Greywater Reuse Guidelines - Appendix G, Title 24, Part 5, California 

Administrative Code. 2 Treated to greater levels than outlined in the California Greywater Reuse Guidelines 3 Treated to levels outlined in the Recycled Water Requirements – Title 22.

A campus workshop was held to determine screening 

criteria for construction and renovations; these criteria 

were then used to review the proposed projects. Key 

conclusions from the workshop included establishing a 

minimum microbial water quality requirement for all 

non-potable water, comparing the cost per gallon of 

non-potable to potable sources, developing a “model 

college” as a planning tool for future projects, and 

considering the educational value of a project in the 

project screening.

Successes and Lessons Learned

The campus study did not recommend which projects 

should be implemented; rather it provided a decision 

analysis framework to select and rank projects as 

triggers occur that require a reduction in use of potable 

water and/or energy. Project selection is a two-stage 

process. First, the projects are grouped into 

“implement,” “maybe implement,” and “currently 

infeasible.” “Implement” reuse projects are those that 

are the easiest to execute and that UCSC sees a clear 

value in implementing right away. The “maybe 

implement” are projects that merit further discussion. 

The projects should also be sorted into immediate, 

near and long-term periods. The second stage 

involves screening and ranking the projects, such as 

with a pairwise analysis, based on the screening 

criteria developed at the beginning of the process.

A small subset of possible projects were selected 

using the Campus Model based on input from USCS

staff; six near-term projects were identified (Table 4). 

A trigger-based approach allows UCSC to implement 

projects activated by flow triggers based on a demand 

matrix. This approach considers meeting immediate 

needs such as droughts, short-term needs when a 

dormitory is being updated and refurbished, and longterm needs for future planned facilities. The outcome 

of this project is being monitored by all UC campuses 

for sustainably meeting growth demands. With the 

implementation of projects identified on the campus, 

UCSC has the opportunity to become a model campus 

for schools and areas in water stressed regions 

throughout the country.

Table 4 Summary of campus reuse projects selected

for near-term implementation

Project Supply Demand

1. East Parking Lot East 

Field Irrigation Rainwater Irrigation

2. Porter College Toilet 

Flushing Rainwater Toilet 

Flushing

3. Biomedical Sciences 

Facility Toilet Flushing Rainwater Toilet 

Flushing

4. Jordan Gulch Middle 

Fork Cooling Towers Rainwater Cooling Towers

5. Irrigation Recycled 

Water Irrigation

6. Family Student Housing 

Landscape Irrigation Graywater Irrigation

References

Maddaus Water Management and UC Santa Cruz. 2007. UC 

Santa Cruz Water Efficiency Survey, Draft Report. 

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2012 Guidelines for Water Reuse

Long-term Effects of the Use of Recycled Water on Soil 

Salinity Levels in Monterey County

Author: B.E. Platts (Monterey Regional Water Pollution Control Agency)

US-CA-Monterey

Project Background or Rationale 

Agriculture in Monterey County, Calif., is more than a 

$3 billion per year industry. Over-pumping of 

groundwater has caused sea water to intrude into 

wells located near the coast. In an effort to reduce 

groundwater extraction in the northern Salinas Valley, 

the Monterey Regional Water Pollution Control Agency 

(MRWPCA) in partnership with the Monterey County 

Water Resources Agency (MCWRA) began providing 

reclaimed water to 12,000 acres (4,860 hectares) of 

prime farmland used to grow cool season vegetables 

in April 1998. The dominant soil types in this region 

are clay loam and heavy clay soils, both of which are 

susceptible to sodium accumulation and water 

penetration problems. Because of grower concerns 

that salts, particularly Na and Cl, in the reclaimed 

water would reduce yield and quality of their crops a 

long-term study was developed to monitor salinity 

levels in commercial vegetable fields. 

Capacity and Type of Reuse 

Application 

The MRWPCA water recycling facility provides a 

relatively constant flow, around 20 mgd (876 L/s) of 

reclaimed water. This rate is inadequate to serve the 

Monterey County Water Recycling Projects (MCWRP) 

service area during peak demand periods. Therefore, 

supplemental wells, tapping groundwater from the 

400-ft (122-m) aquifer, are used to augment the 

reclaimed water supply, as necessary. During periods 

when reclaimed water must be supplemented, 

incidental blending of reclaimed water with well water 

takes place within the pressurized distribution system. 

The prime irrigation water constituents of concern are 

sodium and chloride. Reclaimed water, blended with 

well water, is used to irrigate artichokes, broccoli, 

Brussels sprouts, celery, cauliflower, lettuce, spinach, 

and strawberries within the project area.

Water sampling was conducted throughout the 

recycling project system as standard procedure in the 

MCWRP Monitoring Program. First, MRWPCA’s 

tertiary effluent was sampled on a weekly basis to 

determine the levels of salt present in the reclaimed 

water before blending with the supplemental well 

water. Second, monthly delivery system sampling 

confirmed the specific quality of the water received by 

the growers after supplemental well water was added 

to the reclaimed water. These data were used to 

generate the observed and calculated values of water 

delivered to each field sampling location. The water 

samples were analyzed for pH, conductivity, sodium, 

potassium, magnesium and chloride. The MRWPCA 

laboratory, an accredited laboratory, analyzed the 

water. 

Soil salinity levels were monitored at eight sites 

receiving reclaimed water beginning in the spring of 

2000. The different sites received a range of blends of 

the reclaimed and well water depending on location. 

The range of blends was from 1:1 reclaimed to well 

water to reclaimed water only. The soil was sampled 

three times per year at each site and composites of 4 

cores were collected from the 1- to 36-in (2- to 90-cm) 

depth at 12-in (30-cm) intervals. Soil samples were 

analyzed for pH, electrical conductivity (ECe), 

extractable cations (B, Ca, Mg, Na, and K) and 

extractable anions (Cl, NO3, and SO4). Valley Tech 

Agriculture Lab Services in Tulare, CA, an accredited 

laboratory, analyzed the soil samples.

Water Quality Standards and 

Treatment Technology 

Reclaimed water in the state of California must meet 

Title 22 standards for microbiological quality. However, 

there are no legal requirements in the state of 

California for the quality of reclaimed water in 

reference to agronomic standards for agricultural use. 

MRWPCA’s long-term study early on in the 

development of the water recycling project found no ill 

effects on vegetable production with the use of water 

of the estimated quality to be supplied (Engineering 

Science, 1987). By agronomic standards, the average 

sodium adsorption ratio (SAR) of the reclaimed water 

at 4.94, in combination with an ECw (electrical 

D-38
Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

conductivity) of 1.6, are quite safe for long-term 

irrigation (Richards, 1969). The optimum level of 

sodium in agricultural irrigation water is less than 5.0 

meq/L (115 mg/L) (Ayers, 1985). The average sodium 

in reclaimed water before addition of supplemental 

well water is 7.64 meq/L (175 ppm). The optimum level 

of chloride in agricultural irrigation water is less than 

5.0 meq/L (177 mg/L) (Ayers, 1985). The average 

chloride of reclaimed water before addition of 

supplemental well water is 7.36 meq/L (257 ppm).

Thus, sites receiving reclaimed water only were at risk 

for increasing levels of sodium and chloride. 

After 10 years of monitoring, data showed that soil 

salinity levels exhibited a range of responses including 

increased salinity, decreased salinity and stable 

salinity at different sites. The increase at some sites 

was due to chloride accumulation and was large 

enough to potentially affect chloride sensitive crops 

such as strawberries. The decrease in soil salinity at 

some sites and improved the soil productivity and was 

due to sodium leaching. Sites with stable salinity were 

at values acceptable for growing cool season 

vegetable and berry crops. Average soil salinity values 

were highly correlated with average water quality over 

the length of the study. 

Project Funding and Management 

Practices 

Funding for the salinity monitoring project was 

incorporated into the annual operations and 

maintenance costs by MRWPCA. The water sampling 

plan was an expansion of the standard operating 

procedure. The incremental cost of the soil sampling 

program was approved by the Water Quality and 

Operations committee, which provides input to 

MRWPCA and MCWRA in regard to operational and 

budgetary decisions for the recycling water project. 

MRWPCA, MCWRA and grower representatives have 

reviewed water quality and operations decisions 

monthly since the project became operational in 1998. 

Institutional/Cultural Considerations 

The value of crops and farmland within the MCWRP 

area is significant. At the inception of the water 

recycling projects, MRWPCA and MWCWRA were 

very aware that grower acceptance would be key to 

the project’s success. Therefore, the initial water 

quality study studying agricultural productivity was 

conducted to provide data to the growers. Throughout 

the development of the project, grower support and 

cooperation were good and the Agencies provided 

multiple avenues for grower input and participation in 

making critical decisions. The Water Quality and 

Operations Committee has been the long-term method 

of incorporating stakeholder involvement in the project.

Successes and Lessons Learned

The variation in annual water quality and annual 

variation in soil values for SAR, sodium and chloride at 

each site did not correlate. However, average water 

quality and average soil values for these parameters 

over the ten-year study correlated very well. This 

indicates that short-term studies may not accurately 

reflect changes in soil salinity. Correlation coefficients 

for averages over the study were robust. It is important 

to note that the range of SAR, sodium and chloride in 

the reclaimed water, applied to the different sites, were 

near or only slightly higher than optimum values. This 

demonstrates that slight increases in SAR, sodium and 

chloride in irrigation water are associated with 

increasing levels of SAR, sodium and chloride in the 

heavy clay irrigated soils within the water recycling 

project area. Therefore, initial concerns about changes 

in soil salinity were justified. 

Variability of the trends between different sites is an 

important observation. For all three salinity 

parameters, SAR, sodium and chloride, there were 

multiple trends observed. The different test sites were 

selected to represent the range of water quality, 

farming and soil type conditions within the water 

recycling project area. The wide variety of sites 

resulted in a wide range of soil salinity trends, 

indicating that soil salinity studies should include broad 

range of conditions in order to accurately estimate the 

variability of soil salinity responses.

References

Ayers, R. S. and Westcot, D.W. Water Quality for Agriculture 

– FAO irrigation and drainage paper 29. Rome: Food and 

Agriculture Organization of the United Nations, 1985.

Engineering Science. 1987. Monterey Wastewater 

Reclamation Study for Agriculture final report, 25 October, 

2011. Retrieved on August 30 from

<http://www.mrwpca.org/dwnloads/wr/mwrsa.pdf>.

Richards, L.A. (Ed). Diagnosis and improvement of saline 

and alkali soils. Agriculture Handbook No. 60. Washington: 

U.S.D.A., U.S. Govt. Printing Office, 1969.

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2012 Guidelines for Water Reuse

Metropolitan Water District 

of Southern California’s Local Resource Program

Author: Raymond Jay (Metropolitan Water District)

US-CA-Southern California MWD

Can regional incentive programs maximize 

development of local recycled water projects? 

Background 

The Metropolitan Water District of Southern California 

(Metropolitan) was established in 1928 by the state 

legislature to import water supplies to Southern 

California. Metropolitan is a regional water wholesaler 

to 26 member agencies serving approximately 19 

million people across six counties and delivers 

approximately 1,700 mgd (74,500 L/s) of water from 

the Colorado River Aqueduct and State Water Project 

in its 5,200-square-mile (13,470-km2

) service area. 

Metropolitan is in the Southwest part of California, the 

most urbanized and populous region of the state, with 

slightly more than half of the state’s population. The 

region has a mild, dry subtropical climate with 

approximately 75 percent of the rainfall occurring 

between December and March. The region 

experienced significant drought and regulatory 

reductions in the past challenging Metropolitan’s ability 

to meet growing demand with imported water. As a 

result, Metropolitan is both actively developing 

imported water and incentivizing the development of 

local water resources for the region. 

Metropolitan’s Integrated Resources Plan (IRP), 

provides a long-term strategy to protect the region 

from future supply shortages, with an emphasis on 

water-use efficiency through conservation and local 

supply development. The 2010 IRP calls for meeting 

increased future demand within Southern California 

through expanded local supplies and conservation 

programs. The IRP includes a target of 580,000 acrefeet (189 billion gallons) per year of combined water 

conservation and water recycling, which incorporates 

California’s goal of 20 percent reduction in per capita 

potable water use by the year 2020.

In order to meet long-term water demands, 

Metropolitan provides financial incentives through the 

Local Resource Program (LRP) for recycled water and 

groundwater recovery projects that reduce demand on 

imported water supplies. Metropolitan also provides 

educational outreach to stakeholders to advance 

acceptance of recycled water and the LRP program.

LRP History 

The LRP was initiated in 1982 to provide financial 

incentives to local and member agencies for water 

recycling projects that reduce demand on 

Metropolitan’s imported water supplies and enhance 

local supply reliability. In consultation with its member 

agencies, Metropolitan has made periodic 

improvements to the LRP including refinements to 

eligibility, selection, performance, and incentive levels. 

The program has evolved from a fixed incentive to 

competitive selection and now to its current version 

providing a sliding scale incentive based on actual 

project costs up to Metropolitan’s estimated avoidable 

cost of importing water, currently $250/ac-ft 

($0.20/m3

). The LRP program is currently undergoing 

review by a Local Resources Development Strategy 

Task Force to assess alternate approaches to support 

and expand local resources development.

Metropolitan currently accepts LRP applications on a 

continual basis. Applications are reviewed for 

estimated yield and readiness to proceed. Incentives 

up to $250/ac-ft ($0.20/m3

) are provided monthly 

based on the difference between the actual cost and 

Metropolitan’s prevailing water rates. Incentives are 

reconciled annually. LRP agreements can last up to 25 

years or until the maximum yield is achieved, or until 

the average price of Metropolitan’s water exceeds the 

cost of the project water. 

LRP Analysis

To date, Metropolitan has provided incentives to 64 

water recycling projects throughout Metropolitan’s 

service area (Figure 1). The map in Figure 1 shows 

the wide distribution and success of the LRP. 

Participating projects are expected to produce an 

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

ultimate yield of about 323,000 ac-ft/yr (398 MCM/yr) 

when fully implemented.

Most recycled water developed through the program is 

used for irrigation, groundwater replenishment and 

seawater intrusion barriers for coastal groundwater 

basins. LRP funding can be used for treatment, 

storage, or distribution facilities. Water quality and 

treatment technology for each project is based on the 

proposed use and appropriate California standards. 

Treatment technologies differ among projects.

Since inception of the LRP in 1982, Metropolitan has 

provided approximately $271 million for production of 

about 1.5 million ac-ft (1,850 MCM) of recycled water. 

During fiscal year 2009/10, Metropolitan provided 

$29,000,000 for development of 177,000 ac-ft (218 

MCM) of recycled water.

Successes and Lessons Learned

Several key factors that contribute to the success of 

the LRP include: cost effective financial incentives; 

collaboration among local and regional agencies; 

appropriate recycled water targets; an open 

application process; strong performance provisions 

including requiring construction within 2 years and 

operational within 5 years; allowing long-term 

agreements up to 25 years for the project to be 

completed; and regular refinement of the program 

have contributed to the success of the LRP. 

Summary and Conclusions 

There are several long-standing constraints to the 

development of recycled water including cost, public 

acceptance, institutional coordination, and regulatory 

approval. Metropolitan addresses three of these 

constraints with the LRP. Cost and institutional barriers 

are directly addressed through the LRP. Metropolitan’s 

incentives reduce the cost of recycled water projects 

and Metropolitan’s regional structure provides strong 

institutional coordination and collaboration 

opportunities. The LRP also facilitates public 

acceptance of recycled water by incentivizing local 

projects throughout the region. Although, the LRP 

does not directly address regulatory approval 

constraints, Metropolitan’s participation in 

organizations like the WateReuse Association 

facilitates sound regulatory reform. The LRP has 

played a significant and important role in expanding 

the number of recycled water projects developed in 

Southern California. 

Recycled water projects require large upfront capital 

and take a significant amount of time to build and 

become fully utilized. Without strong local support, 

development of additional recycled water projects is 

slow. 

California is unlikely to meet recycled water goals 

adopted in the State Recycled Water Policy without 

regional support like Metropolitan’s LRP. Recycled 

water projects can be increased through incentive 

programs like the LRP but also require strong local 

commitment and often additional State and federal 

funding. Funding sources for recycled water including 

SRF and Title XVI are necessary to maximizing 

development of local recycled water projects.

References

Metropolitan Water District of Southern California. 2010 

Integrated Water Resources Plan, Report 1373. 

Metropolitan Water District of Southern California. 2011 

Local Resources Program summary report. 

Figure 1

Local Resource Program Recycled Water Projects

Metropolitan Water District 

of Southern California

2/3/11

Number 

of 

Projects

Contract 

Yield 

(AFY)

Deliveries 

to Date 

(AF)

Incentives to 

Date 

64 323,000 1,490,000 $271,000,000

Recycled Water Projects

Local Resource Program

D-41
2012 Guidelines for Water Reuse

Montebello Forebay Groundwater Recharge Project using 

Recycled Water, Los Angeles County, California

Authors: Monica Gasca, P.E. and Earle Hartling 

(Los Angeles County Sanitation Districts)

US-CA-Los Angeles County

Project Background

The Montebello Forebay Groundwater Recharge 

Project (MFGRP) has successfully been recharging 

the groundwater with recycled water since August 20, 

1962. This is the oldest planned groundwater recharge 

project using recycled water in California. To date, 

over 1.6 million ac-ft (1,970 MCM) of recycled water 

has been recharged at the MFGRP to replenish the 

Central Groundwater Basin, which provides 40 percent 

of the total water supply for Los Angeles County. 

In the 1950’s, following a rapid population growth in 

the region, excessive and unregulated pumping 

resulted in an overdraft that dropped the groundwater 

table and allowed seawater to intrude into the aquifer. 

In response, the Water Replenishment District of 

Southern California (WRD) was formed to manage this 

basin by regulating pumping and purchasing 

supplemental water supplies for replenishing the 

groundwater.

Sources of groundwater replenishment in the Central 

Basin include recycled water, imported river water 

(Colorado River and State Project water), and local 

storm runoff. Use of recycled water for replenishment 

began at the Montebello Forebay area of the Central 

Basin in 1962, following construction of the Whittier 

Narrows WRP. The effectiveness of reuse from the 

Whittier Narrows WRP led to the decision to construct 

additional WRPs in the Los Angeles area in the 

1970’s, two of which (San Jose Creek and Pomona) 

also contribute to the recharge of the Central Basin. In 

the late 1970’s, the WRPs were upgraded with tertiary 

treatment resulting in production of an effluent that met 

federal and state drinking water standards for heavy 

metals, pesticides, trace organics, major minerals, 

nitrogen, and radionuclides, and had extremely low 

levels of microorganisms and turbidity. 

In the early 2000’s, the WRPs were upgraded again, to 

provide nitrification/denitrification, further improving the 

quality of the recycled water. In the late 2000’s, 

Figure 1

Montebello Forebay Groundwater Recharge Sites

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

sequential chlorination was implemented, minimizing 

production of trihalomethanes and Nnitrosodimethylamine. And in 2011, the Whittier 

Narrows WRP began using UV disinfection. All of 

these water quality improvements increased the 

suitability of recycled water for indirect augmentation 

of potable water supplies through groundwater 

recharge (Table 1). 

Project Operation

Water is percolated into the groundwater using two 

sets of spreading grounds (Figure 1): the Rio Hondo 

Coastal Spreading Grounds, which consist of 570 ac 

(235 ha) with 20 individual basins, and the San Gabriel 

Coastal Spreading Grounds which consists of 128 ac 

(52 ha) with 3 individual basins, and within portions of 

the San Gabriel River (308 ac [125 ha]). Recycled 

water is conveyed to spreading grounds by gravity 

through existing waterways and operated under a 

wetting/drying cycle designed to optimize inflow and 

discourage development of vectors. Extensive 

monitoring is conducted at the WRPs, at the 

headworks to the spreading grounds, and in the 

groundwater aquifers.

Project Effectiveness

In a typical year, more recycled water from the 

Sanitation Districts’ WRPs is used for groundwater 

recharge than for all other (direct non-potable) 

applications combined due to its cost-effectiveness. 

The major advantage of the MFGRP is that it avoids 

significant construction costs and energy requirements 

of a dual distribution system for delivering recycled 

water to direct non-potable users by taking advantage 

of existing waterways to convey the water to spreading 

grounds. In addition, greater quantities of recycled 

water can be conserved by utilizing the substantial 

under-ground storage capacities of the local aquifers, 

and there is no strict daily, or even seasonal, 

timeframe in which recharge must take place; it can 

occur whenever recycled water supplies are available 

and infiltration capacity is not taken up by storm runoff.

Project Management and Funding 

The MFGRP is jointly managed by three agencies: 

WRD manages the basin, Los Angeles County 

Department of Public Works (LACDPW) operates the 

system, and Los Angeles County Sanitation Districts 

(Sanitation Districts) provides the recycled water.

Funding is provided by the respective agencies. 

Treatment is funded by the Sanitation Districts through 

charges to users of its sewerage system. The recycled 

water must be treated to a tertiary level even if it’s to 

be discharged to the river and wasted to the ocean; 

therefore, no additional treatment costs are incurred 

for this project. Delivery costs are minimal, as the 

WRPs were constructed alongside rivers for disposal 

and are upstream of the spreading grounds. Recycled 

water is delivered by gravity through existing 

infrastructure, obviating the need for additional capital 

or energy costs. Operation costs for the river channels, 

through which the recycled water is transported, and 

the spreading grounds are incurred by LACDPW as 

part of their ongoing maintenance and operation of 

their flood control system and their mission to 

conserve local water. Recycled water is purchased by 

WRD as part of their mission to increase storage of 

groundwater in the Central Groundwater Basin. The 

Sanitation Districts sells recycled water to WRD at a 

significant discount over imported water for the same 

purpose. Groundwater monitoring costs are also borne 

by WRD as part of their mission to ensure the 

groundwater quality in their service area. WRD’s funds 

are derived from replenishment fees collected from 

pumpers of groundwater in their service area, which 

are collected as part of the basin adjudication.

Project Driven Research 

The three agencies involved have successfully 

collaborated to perform in-depth research over the 

years to reassure regulators and the public that 

recycled water is safe for aquifer recharge. The 

effectiveness of Soil Aquifer Treatment (SAT) has 

been demonstrated for decades, and a number of 

health effects studies related to the use of 

groundwater for human consumption have been 

undertaken over that time. In addition, numerous 

studies have been performed on the presence and fate 

of pharmaceuticals and personal care products in the 

water, virus fate and transport, recycled water 

residence time in the aquifers using tracer tests, and 

total organic carbon reduction. None of these studies 

have found any adverse health effects associated with 

using the recycled water for groundwater recharge in 

the Montebello Forebay. 

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Table 1 Average recycled water quality and California drinking water limits October 2010-September 2011

Constituent Units SJC- East SJC- West Whit. Nar. Pomona Limit

Organics

1,1-Dichloroethane ug/L < 0.50 < 0.50 < 0.50 < 0.50 5 P

1,1-Dichloroethene ug/L < 0.50 < 0.50 < 0.50 < 0.50 6 P

1,1,1-Trichloroethane ug/L < 0.50 < 0.50 < 0.50 < 0.50 200 P

1,1,2-Trichloroethane ug/L < 0.50 < 0.50 < 0.50 < 0.50 5 P

1,1,2,2-Tetrachloroethane ug/L < 0.50 < 0.50 < 0.50 < 0.50 1 P

1,2-Dichloroethane ug/L < 0.50 < 0.50 < 0.50 < 0.50 0.5 P

1,2-Dichloropropane ug/L < 0.50 < 0.50 < 0.50 < 0.50 5 P

1,2,4-Trichlorobenzene ug/L < 5.0 < 5.0 < 5.0 < 5.0 5 P

2,4-D ug/L < 0.56 < 0.60 < 0.53 < 0.53 70 P

2,4,5-TP (silvex) ug/L < 0.56 < 0.60 < 0.53 < 0.53 50 P

Atrazine ug/L < 0.12 < 0.10 < 0.11 < 0.11 1 P

Benzene ug/L < 0.50 < 0.50 < 0.50 < 0.50 1 P

bis(2-Ethylhexyl) phthalate ug/L < 2.0 < 2.0 < 2.0 < 2.0 4 P

Carbon tetrachloride ug/L < 0.50 < 0.50 < 0.50 < 0.50 0.5 P

Chlorobenzene ug/L < 0.50 < 0.50 < 0.50 < 0.50 70 P

cis-1,2-Dichloroethene ug/L < 0.50 < 0.50 < 0.50 < 0.50 6 P

Endrin ug/L < 0.01 < 0.01 < 0.01 < 0.01 2 P

Ethylbenzene ug/L < 0.50 < 0.50 < 0.50 < 0.50 300 P

Gamma-BHC (Lindane) ug/L < 0.01 < 0.01 < 0.01 < 0.01 0.2 P

Heptachlor ug/L < 0.01 < 0.01 < 0.01 < 0.01 0.01 P

Heptachlor epoxide ug/L < 0.01 < 0.01 < 0.01 < 0.01 0.01 P

Methoxychlor ug/L < 0.01 < 0.01 < 0.01 < 0.01 30 P

Methylene chloride ug/L < 0.50 < 0.50 < 0.50 < 0.50 5 P

o-Dichlorobenzene ug/L < 0.50 < 0.50 < 0.50 < 0.50 600 P

p-Dichlorobenzene ug/L < 0.50 < 0.50 < 0.50 < 0.50 5 P

Pentachlorophenol ug/L < 1.0 < 1.0 < 1.0 < 1.0 1 P

Polychlorinated biphenyls (PCBs) ug/L ND ND ND ND 0.5 P

Simazine ug/L < 0.12 < 0.10 < 0.11 < 0.11 4 P

Tetrachloroethene ug/L < 0.50 < 0.50 < 0.50 < 0.50 5 P

Toluene ug/L < 0.50 < 0.50 < 0.50 < 0.50 150 P

Toxaphene ug/L < 0.5 < 0.5 < 0.5 < 0.5 3 P

trans-1,2-Dichloroethene ug/L < 0.50 < 0.50 < 0.50 < 0.50 10 P

Trichloroethene ug/L < 0.50 < 0.50 < 0.50 < 0.50 5 P

Trichlorofluoromethane ug/L < 1.0 < 1.0 < 1.0 < 1.0 150 P

Vinyl chloride ug/L < 0.50 < 0.50 < 0.50 < 0.50 0.5 P

Xylenes ug/L ND ND ND ND 1750 P

Inorganics

Arsenic ug/L 0.347 0. 592 0. 722 0. 295 10 P

Barium ug/L 61.6 26.9 38.8 34.5 1000 P

Cadmium ug/L < 0.20 < 0.20 < 0.20 < 0.20 5 P

Total Chromium ug/L 0.74 0.83 1.0 0.83 50 P

Copper ug/L 3.00 5.69 5.00 5.47 1000 S

Fluoride mg/L 0.446 0.708 0.685 0.342 2 P

Iron ug/L 66 51 25 29 300 S

Manganese ug/L 23.5 25.4 9.38 6.17 50 S

Mercury ug/L 0.00123 0.00150 0.00245 0.00147 2 P

Nickel ug/L 5.83 3.01 7.83 1.96 100 P

Nitrate + Nitrite nitrogen mg/L 4.50 9.49 6.59 6.90 10 P

Selenium ug/L <1.00 <1.00 <1.00 <1.00 50 P

Silver ug/L < 0.20 < 0.20 < 0.20 < 0.20 100 S

Zinc ug/L 52.4 47.0 56.3 62.3

Other Constituents

Color CU 9 8 13 14 15 S

Surfactant (MBAS) Mg/L < 0.10 < 0.10 < 0.10 0.0083 0.5 S

Gross alpha radioactivity pCi/L 0.898 1.40 1.02 0.670 15 P

P = Primary Maximum Contaminant Level (health)

S = Secondary Maximum Contaminant Level (aesthetic)

Values with “<” were below the Reporting Detection Limit reported

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Regulatory Climate 

Replenishment of the groundwater with recycled water 

in Montebello Forebay is regulated by the California 

Department of Public Health (CDPH) and Los Angeles 

Regional Water Quality Control Board (RWQCB) for 

protection of human health and of beneficial uses of 

groundwater. The recycled water used at the MFGRP 

receives rigorous tertiary treatment that ensures the 

high water quality standards are met. 

Initially, the annual amount of recycled water 

recharged was limited to 32,700 ac-ft/yr (40 MCM/yr), 

which was determined to be the amount of effluent that 

had historically entered the groundwater from other 

sources. In 1987 (following the Health Effects Study), 

the maximum amount of recycled water used for 

recharge was increased to 50,000 ac-ft/yr (62 

MCM/yr). In 1991, this was again increased to 60,000 

ac-ft/yr (74 MCM/yr) in order to allow WRD to make up 

for those years in which excessive rainfall runoff 

prevented full utilization of the previous recycled water 

allotment. 

In April 2009, the limit was revised again, as the 

RWQCB, with CDPH’s concurrence, removed the 

quantity limits, replacing them with a dilution-based 

limitation of no more than 35 percent in any running 

five year period. WRD estimates that this could allow 

for the recharge of an additional 5,000 to 7,000 ac-ft/yr 

(6.2 to 8.6 MCM/yr) of recycled water, with a long-term 

goal of increasing replenishment with recycled water to 

75,000 ac-ft/yr (93 MCM/yr). Currently, about 44,000 

ac-ft/yr (54 MCM/yr) of disinfected tertiary municipal 

wastewater is being delivered to the MFGRP for 

groundwater recharge.

Successes

The MFGRP provides a new water supply, roughly 

equivalent to the demands of a quarter of a million 

people. After fifty years of operation, the WRPs 

continue to operate consistently, producing an 

extremely high quality effluent, and monitoring 

continues to indicate that groundwater quality has not 

been adversely impacted. In addition, the use of 

recycled water in lieu of imported water for 

replenishing the groundwater has saved tens of 

millions of dollars a year in water purchases.

Because recycled water is highly reliable, cost 

effective, locally controlled, and drought-resistant, 

there are ongoing plans to increase the amount of 

recycled water recharged in the Central Groundwater 

Basin and ultimately eliminate the basin’s dependence 

on imported water.

References

Nellor, 1984. Health Effects Study.

Rand Corporation, 1996. Groundwater Recharge with 

Reclaimed Water: An Epidemiological Assessment in Los 

Angeles County, 1987-1991.

Rand Corporation, 1999. Groundwater Recharge with 

Reclaimed Water: Birth Outcomes in Los Angeles County, 

1982-1993.

Fox, Nellor, et al., 2006. An Investigation of Soil Aquifer 

Treatment for Sustainable Water Reuse.

Sanitation Districts of Los Angeles County, 1977. Pomona 

Virus Study.

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2012 Guidelines for Water Reuse

Recycled Water Supplements Lake Elsinore

Author: Ronald E. Young, P.E., DEE (Elsinore Valley Municipal Water District) 

US-CA-Elsinore Valley

Project Background or Rationale 

As imported water becomes more expensive, finding 

ways to make the most of existing water supplies 

becomes increasingly important. One of the best ways 

to stretch supplies is to recycle water. Elsinore Valley 

Municipal Water District (EVMWD) in southern 

California is finding more ways to use recycled water, 

including water for local playgrounds, commercial 

landscapes and most importantly, maintaining stable 

water levels in Lake Elsinore.

Lake Elsinore is southern California’s largest natural 

lake and is situated at the bottom of the San Jacinto 

Watershed. Because Lake Elsinore is a natural lake, 

fed only by rain and natural runoff, with annual 

evaporation of 4.5 feet, it has been plagued, for 

decades, by low water levels and high concentrations 

of nutrients. Large amounts of nutrients are

responsible for producing algae blooms which choke 

off oxygen in the lake and result in fish kills. The lake 

is a full body contact recreational lake with fishing, 

speed boats, beaches and swimming areas. The lake 

is not a drinking water source.

Water Quality Standards and 

Treatment Technology 

In 1997, a local task force comprised of community 

leaders issued a white paper on the benefits and 

safety of using recycled water in the community and to 

fill Lake Elsinore. In 2003, through a 2-year pilot 

program, EVMWD implemented an extensive 

monitoring program to examine biological and nutrient 

impacts that recycled water might have on water 

quality in the outflow channel and throughout the entire 

lake. 

The monitoring program was administered by Dr. 

Michael Anderson of University of California Riverside. 

The Anderson report was used by the Regional Water 

Quality Control Board to set total maximum daily load 

(TMDL) load allocations in 2004, which were then 

translated into the 2005 National Pollutant Discharge 

Elimination System (NPDES) Permit for EVMWD. This 

resulted in a lake target value of total phosphorus of 

0.01 mg/l by 2015 and a reclaimed water limit of 0.5 

mg/l based on phosphorus mass loading, instead of 

concentration. 

Thus, phosphorus reduction was needed and 

ultimately grant funded to achieve the NPDES 

requirements. The Anderson report concluded 

“stabilizing the lake level may be of greater short-term 

concern than increasing nutrient concentrations. The 

poorest water quality observed in the lake was, in fact 

more closely associated with declining lake level than 

inputs of recycled water or high lake nutrient 

concentrations.”

In 2005, the Regional Water Quality Control Board 

approved EVMWD’s two-year pilot project to introduce 

recycled water into Lake Elsinore. Over this two year 

period EVMWD successfully completed the various 

State required permits to be able to permanently 

provide recycled water to Lake Elsinore as part of 

TMDL requirements for the watershed.

Project Summary

The two year EVMWD pilot study resulted in a 

construction project including almost 4,000 feet of 

pipeline, at a cost of $2.2 million. The project delivers 

approximately 5 mgd (219 L/s) of recycled water to 

Lake Elsinore. Also included in the project, was repair 

and retrofit of three local, shallow groundwater wells 

that deliver approximately 1 mgd (44 L/s) of nonpotable water to Lake Elsinore. An additional $1.5 

million project added chemical phosphorus removal to 

the Regional WRP. 

The project was funded by EVMWD and the Lake 

Elsinore San Jacinto Watershed Authority (LESJWA). 

LESJWA was formed in 2000 to improve water quality 

and protect wildlife habitats in the 700 square mile 

watershed that runs from the San Jacinto Mountains to 

Lake Elsinore. The annual operations and 

maintenance costs are borne equally between 

EVMWD and the City of Lake Elsinore through a 

cooperative agreement that outlines funding guidelines 

and operating requirements.

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Successes and Lessons Learned

EVMWD received several honors for its state of the art 

reclamation facility and the recycled water program for 

Lake Elsinore including being named 2006 Plant of the 

Year by the California Water Environment Association 

and the Theodore Roosevelt Environmental Award 

from the California Association of Water Agencies. 

Figure 1 shows the Project Commemoration 

Ceremony.

Figure 1

October 2007 Commemoration Ceremony (Photo credit: Elsinore Valley Municipal Water District)

D-47
2012 Guidelines for Water Reuse

Replacing Potable Water with Recycled Water for 

Sustainable Agricultural Use

Author: Graham Juby, PhD, P.E. (Carollo Engineers)

US-CA-Temecula

Project Background

The city of Temecula, Calif., is located about 60 miles 

(97 km) north of San Diego. To the east and west lie 

agricultural areas that produce avocados, citrus and 

grapes. The agricultural area falls within the boundary 

of the Rancho California Water District (Rancho 

Water), which provides irrigation water to the local 

farmers. Rancho Water provides over 30,000 ac-ft/yr 

(37 MCM/yr) of fully-treated, drinking water for 

irrigation. Recognizing that delivering such large 

volumes of drinking water to agricultural users in 

water-short southern California is unsustainable, and 

the fact that discounted water rates for farmers was 

being phased out, Rancho Water conducted a study to 

determine the feasibility and cost of delivering recycled 

water. 

In addition to purchasing irrigation water, farmers 

spend considerable funds on commercial fertilizers to 

provide nutrients to their crops, while treatment 

facilities spend considerable sums to remove some of 

the very same nutrients. The opportunity to provide 

nutrient-rich recycled water to farmers would benefit 

both sectors. Additionally, recycled irrigation water 

could improve plant nutrient uptake, and reduce 

nutrient runoff, providing another benefit to the region.

Capacity and Type of Reuse 

Application 

Approximately 30,000 ac-ft/yr (37 MCM/yr) of drinking 

water is applied to the east and west farming areas. 

This project would be built in phases to ultimately 

replace the drinking water with 18,000 ac-ft/yr (22 

MCM/yr) of recycled water and 12,000 AFY (315

MCM/yr) of untreated drinking water. 

Recycled water would be obtained from two existing 

WWTPs centrally located between the eastern and 

western agricultural areas. One treatment plant is 

owned and operated by Rancho Water and has a 

capacity of 5 mgd (219 L/s). The second facility is 

owned and operated by the Eastern Municipal Water 

District and has a current capacity of 18 mgd, (790 L/s) 

expandable to 23 mgd (1000 L/s). Some of the treated 

tertiary effluent produced by these plants is already 

recycled for landscape irrigation, so the agricultural 

reuse project would make use of any remaining water. 

In order to implement such a project, significant new 

infrastructure would be needed to distribute the 

recycled water. Most of the agricultural demand, about 

25,000 AFY (8.1 billion gallons), is in the western 

region (Santa Rosa Division) where avocado farms are 

located. This area also has steep terrain (Figure 1) 

and construction of new distribution pipes will be 

challenging.

Untreated surface water supply would be used to 

make up the required volume to match irrigation 

demands; water would be provided from the existing 

connections to Metropolitan Water District of Southern 

California’s raw water system. Seasonal storage would 

be provided to match seasonal demand for agricultural 

irrigation water by constructing additional storage 

volume to augment Rancho Water’s existing seasonal 

irrigation storage capacity.

Water Quality Standards and 

Treatment Technology 

Water quality goals for the project were twofold. The 

first is the requirement of the San Diego Regional 

Water Quality Control Board that specifies irrigation 

water contains less than 500 mg/L of total dissolved 

Figure 1

Avocado farming area, west of Temecula, Calif. (Photo 

credit: Graham Juby)

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

solids (TDS), which applies to both the eastern and 

western areas that overlie groundwater basins. The 

second water quality requirement is limits for chloride, 

sulfate and boron, which are key considerations for 

irrigation of avocados, citrus and grapes.

The two WWTPs produce tertiary effluent containing 

between 690 and 720 mg/L TDS thus some salt 

removal would be required. However, once the TDS is 

reduced to below 500 mg/L to satisfy the groundwater 

basin objectives, the concentrations of other 

constituents that are of concern for agricultural use are 

also reduced to acceptable levels (Welch, 2006).

To achieve the desired recycled water quality for 

agricultural irrigation, conventional and advanced 

treatment would be required. Two treatment 

approaches were evaluated. The first treatment 

approach (Figure 2) would use microfiltration (MF) 

and reverse osmosis (RO) to treat about a third of the 

secondary effluent to result in a combined stream with 

the desired TDS limit of less than 500 mg/L. 

Considering that wastewater treatment includes 

nutrient removal, this approach would result in 

irrigation water that would apply nitrogen and 

phosphate at a rate of about 17 and 16 lb/ac, 

respectively, based on present agricultural-use water 

data.

Such nutrient application rates are much lower than 

typical rates used in California for oranges, avocados 

and grapes; which are 85, 116 and 33 lb/ac (95, 130 

and 37 kg/ha) for nitrogen, and 34, 61 and 38 lb/ac 

(38, 68 and 43 kg/ha) for phosphate, respectively 

(Agricultural Statistics Board, 2004). Consequently, 

farmers would still need to apply significant quantities 

of commercial fertilizer.

A novel treatment approach that was also evaluated 

included the use of MF and RO treatment of primary 

effluent rather than secondary effluent. This approach 

would allow nutrients in the primary effluent be 

retained through the MF step, resulting in higher 

concentrations after blending with one third of the 

stream that passes through RO, as shown in Figure 3. 

The recycled water, in this case, would increase 

irrigation water nitrogen and phosphorus 

concentrations such that the application rates would 

become 124 and 25 lb/acre (139 and 28 kg/ha), for 

nitrogen and phosphate, respectively. These 

application rates would provide sufficient nitrogen for 

oranges, avocados and grapes; meaning that farmers 

would not need to supplement nutrients with 

commercial fertilizers.

As shown in Figure 3, other nutrient-rich side streams 

in the treatment plant (such as the belt press filtrate) 

could be utilized to further increase nutrient 

concentrations in the agricultural reuse water, avoiding 

the energy-intensive treatment of the high-nutrient 

return stream in the plant. By blending streams 

appropriately, nutrient levels could be controlled to 

supply a suitable range for agricultural reuse.

Providing water and nutrients are benefits of the 

treatment approach described in Figure 3; energy 

savings would be significant too. Avoiding the need for 

nitrogen removal in the secondary treatment process 

would save about 2060 BTU/lb (4.8 GJ/tonne) of 

nitrogen removed. But the biggest energy saving 

comes from manufacturing less commercial fertilizer – 

about ten times more energy than that needed to 

remove nitrogen via wastewater treatment, equating to 

19,000 BTU/lb (44 GJ/tonne) of nitrogen (EFMA, 

2007). For Phase I of the project, the 10,000 ac-ft/yr 

(12 MCM/yr) reuse is estimated to result in energy 

savings (associated with nitrogen) equivalent to 3,600 

Figure 3

Use of primary effluent as source water results in 

higher nutrient concentrations in recycled water

Figure 2

Conventional approach to producing partially 

desalted recycled water

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

bbl/yr of oil, also reducing greenhouse gas emissions 

by 2800 tons/yr (2,500 tonnes/yr) of carbon dioxide 

equivalent (Juby et al., 2010). 

Project Costs

Project cost estimates were updated in 2010 to include 

avoided costs and the latest projections for potable 

water costs in the region. Avoided costs included 

savings that would result from implementation of the 

project, such as the costs saved by importing less 

water to the region, and capital and operations and 

maintenance (O&M) costs that would be saved as a 

result of the modified treatment process.

The project was assumed to have a 30-year life, and 

interest on capital was calculated at an annual rate of 

5 percent. Capital and O&M costs were annualized to 

develop an annual total, from which unit costs were 

calculated. The cost analysis showed that building the 

project to include 18,000 ac-ft/yr (22 MCM/yr) of 

partially-desalted, recycled water would result in the 

biggest long-term savings, $545 million over the life of 

the project. The project payback is projected to be 

between 8 and 10 years when compared with the “donothing” alternative that assumes continued use of 

potable water for crop irrigation.

Project Funding and Management 

Practices 

Rancho Water applied for Title XVI funding through the 

U.S. Department of the Interior, Bureau of 

Reclamation. A total of $20 million was available for 

the project from this source. An additional $4 million 

was potentially available through the State of 

California via Proposition 84, and the Metropolitan 

Water District of Southern California offered a credit of 

$250/ac-ft ($0.20/m3

) of recycled water used to off-set 

potable water production through a local resources 

program.

A key to success of potential funding applications was 

the fact that this project had regional benefits in terms 

of its ability to reduce the demand for imported water 

and that it would free-up significant treated potable 

water; enough for a city of more than 120,000 people. 

The project’s more sustainable approach in terms of 

water use and energy savings were also important 

success factors.

Institutional/Cultural Considerations 

The key aspect for the overall success of this project is 

the availability of excess wastewater from the local 

treatment plants. Linked to that factor, is the 

institutional issue of sharing water between agencies. 

The economic downturn in Southern California since 

2008, coupled with a drive to increase water 

conservation, has resulted in wastewater flows 

declining to most treatment plants. Concurrently, the 

rapid increase in potable water cost has resulted in 

two challenges for this project. First, the decline in 

wastewater flows has delayed the implementation plan 

for the project by several years. Second, other uses for 

recycled water have left less wastewater available for 

this project. 

Consequently, Rancho Water has recently 

investigated smaller, alternative projects that would 

utilize around 5,000 to 10,000 ac-ft/yr (6 to 2 MCM/yr) 

of recycled water. These projects would not involve 

conversion of the entire agricultural region to recycled 

water; but one alternative would convert the entire 

eastern farming region (vineyards) to recycled water. 

The current lack of “excess” wastewater flow for reuse 

equates to higher risk of stranded assets, if costly 

infrastructure is installed without guarantee that water 

will be available in future. Another risk to the project is 

if farmers go out of business, due to the rising cost of 

potable water, before the recycled water project can 

be built.

Successes and Lessons Learned

This project is still in development however, a key 

lesson for success is securing wastewater resources 

for recycled water projects early in arid regions where 

these resources are in high demand.

References

Agricultural Statistics Board. 2004. Agricultural Chemical 

Usage 2003 Fruit Summary, NASS, USDA, August.

EFMA. 2007. European Fertilizer Manufacturers Association, 

Harvesting Energy with Fertilizers, Brussels, Belgium. 

Retrieved on August 29, 2012 from <www.efma.org>. 

Juby, G.J.G, Zacheis, G.A and Louck, P. 2010. “Possible 

Paradigm Shift Ahead”, Water Environment & Technology, 

January pp 44-48.

Welch, M.R. 2006. “Demineralization and Non-Potable 

Conversion Project: Recommended Recycled Water 

Quality”, Report to Carollo Engineers, Inc.

D-50
2012 Guidelines for Water Reuse

Water Reuse in the 

Santa Ana River Watershed

Author: Celeste Cantú (Santa Ana Watershed Project Authority)

US-CA-Santa Ana River

Project Background

Water reuse has long been seen as key to integrated 

regional water management planning in the Santa Ana 

River watershed and has been used as a strategy to 

stretch water supplies and improve supply reliability. 

The watershed includes most of Orange County, the 

western corner of Riverside County, the southwestern 

corner of San Bernardino County and a small portion 

of Los Angeles County in Southern California. When 

the watershed is viewed as a system, a 

comprehensive approach to managing water can be 

implemented, allowing available water to be matched 

to end uses by quality. For example, in the Santa Ana 

River watershed, there is significant demand for 

irrigation of landscaping, parks, golf courses and 

sports fields. Typical domestic wastewater can be 

recycled for these purposes without much more 

expense than would be required to discharge the 

wastewater legally to local receiving waters. In this 

case, reuse requires less energy than pumping 

imported water over the mountains into the watershed. 

Additionally, recycled water often contains nutrients, 

which can reduce the fertilizer needs for smart 

landscape managers.

Project Development

The Santa Ana Watershed Project Authority (SAWPA) 

has led the agencies and stakeholders in the 

watershed in a comprehensive, integrated planning 

process called “One Water One Watershed” (OWOW). 

The OWOW Steering Committee and the SAWPA 

Commission have developed goals for the watershed, 

several of which are related to water reuse, including 

increasing use of recycled water, matching water 

quality with intended uses, leveraging existing assets, 

reducing energy consumption, and identifying projects 

with multiple benefits. 

SAWPA’s member agencies have been leaders in 

reusing domestic wastewater. The Eastern Municipal 

Water District, Inland Empire Utilities Agency, Orange 

County Water District, and Western Municipal Water 

District have all developed recycled water supplies; 

other retail agencies in the watershed have also been 

very aggressive in making use of recycled water. 

Capacity and Type of Reuse 

Application 

The Santa Ana River watershed currently meets 10 

percent of its total demand in average years with water 

reused within the watershed, and SAWPA expects this 

to increase to 15 percent by 2030. Recycled water 

uses include municipal use, agricultural irrigation, 

groundwater recharge, habitat and environmental 

protection, industrial use, and lake stabilization. 

California currently recycles approximately 725,000 

ac-ft (894 MCM) per year and has a goal of reusing 

2.5 million ac-ft (3080 MCM) per year. This watershed 

represents a significant opportunity for the State to 

reach its recycling goal as the Santa Ana River 

watershed already reuses 217,000 ac-ft (268 MCM) 

per year or 29 percent of all of California’s current 

reuse. The OWOW plan envisions increasing that to 

437,000 ac-ft (539 MCM). 

Water Quality Standards 

Another of the OWOW goals includes salinity 

management, which has also been a key effort of 

SAWPA for forty years on a watershed scale. Salt is 

introduced into the watershed by way of domestic 

sewage, industrial discharges, and the importation of 

water. A side effect of increasingly efficient water use 

is that less water flows to the ocean, which normally 

also reduces the export of salt. As a result, water 

reused in the watershed can cause a salinity increase 

which has undesirable consequences. 

Thus, SAWPA and its member agencies constructed 

the Inland Empire Brine Line, which is used to collect 

salty wastes from industry, allowing those economic 

activities to thrive while keeping the salt segregated 

from the river, the groundwater, and the reusable 

wastewater. The isolation and export of brine creates 

capacity for reuse of domestic wastewater. 

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2012 Guidelines for Water Reuse

Importation of water from the Colorado River accounts 

for about one-third of the salt inputs to the system. In 

addition to the Inland Empire Brine Line, SAWPA and 

its member agencies also invested in groundwater 

desalters, which also discharge brine to the Inland 

Empire Brine Line. 

In the lower part of the watershed, another SAWPA 

member agency, the Orange County Water District 

(OCWD), operates extensive diversion and recharge 

facilities to capture as much surface flow as possible 

and move it to groundwater storage. For decades 

OCWD has used recycled water to protect the basin 

from salinity by injecting it to create a seawater 

intrusion barrier. More recently, OCWD has partnered 

with the Orange County Sanitation District to develop 

the Groundwater Replenishment System (GWRS), the 

premier indirect potable reuse project in the U.S., 

which treats and percolates 72,000 ac-ft (89 MCM) per 

year back into the basin for storage and reuse. The 

OCWD GWRS uses RO treatment to remove salt, 

ultimately keeping it out of the basin. 

The upper watershed’s desalters and the Inland 

Empire Brine Line reduce the salinity of the surface 

flows that OCWD captures and recharges, also 

protecting the quality of the groundwater resource. As

a result, the Orange County groundwater basin 

supplies 65 to 75 percent of the water needs of the 2.5 

million residents of north Orange County. 

Successes and Lessons Learned

The Santa Ana River watershed experience illustrates 

the need for a comprehensive, watershed approach to 

resources management, as even laudable actions can 

have negative impacts that need to be balanced. The 

desire to increase water use efficiency and to reuse 

water to stretch supplies and improve reliability has 

focused attention on the need to manage salinity. The 

need to integrate strategies and invest in significant 

infrastructure to achieve these goals required 

collaboration and trust among stakeholders throughout 

the watershed. 

The communities and stakeholders in the watershed 

are now implementing the OWOW plan and will 

continue to look for ways to optimize available water 

resources. Moving forward, the OWOW Steering 

Committee and the SAWPA Commission will look 

even harder at addressing the long-term impacts 

associated with climate change. In Southern 

California, this is likely to create greater impetus to 

increase efficiency and maximize the use of local 

supplies and groundwater storage. Water reuse, storm 

water management, and salinity management are key 

strategies in the plan, and the SAWPA and its member 

agencies will continue to aid watershed stakeholders 

in developing new cooperative agreements for 

implementing strategies in the context of a systemwide plan.

D-52
2012 Guidelines for Water Reuse

Leo J. Vander Lans Water Treatment Facility

Authors: R. Bruce Chalmers, P.E. (CDM Smith) and Paul Fu, P.E. 

(Water Replenishment District)

US-CA-Vander Lans

Project Background or Rationale 

The Water Replenishment District of Southern 

California (WRD) was established in 1959 to manage 

groundwater resources of the Central and West Coast 

Basins. WRD is responsible for maintaining adequate 

groundwater supplies, preventing seawater intrusion 

into underground aquifers, and protecting groundwater 

quality against contamination. WRD operates a 

program to artificially replenish the Central and West 

Coast Groundwater Basins by spreading and injecting 

replenishment water. Several sources are used for 

replenishment, including imported water and treated 

recycled water. WRD utilizes spreading facilities and 

three seawater intrusion barriers, including the 

Alamitos Seawater Intrusion Barrier. 

Capacity and Type of Reuse 

Application 

WRD constructed the Leo J. Vander Lans Water 

Treatment Facility (LVLWTF) in 2005 with a capacity 

of 3 mgd (130 L/s). The plant is being expanded to 

increase capacity to 8 mgd (350 L/s). WRD receives 

tertiary treated (Title 22) reclaimed water from the Los 

Angeles County Sanitation Districts (LACSD) Long 

Beach Water Reclamation Plant (LBWRP). WRD is 

also planning to acquire tertiary effluent from LACSD’s 

Los Coyotes Water Reclamation Plant (LCWRP), 

approximately 6 miles (9.6 km) to the north of 

LVLWTF, to provide a sufficient supply of water to 

meet expansion requirements of the LVLWTF.

Treated water from the existing plant is mixed with 

imported potable water prior to injection into the 

Alamitos Barrier. The LVLWTF expansion will provide 

the entire supply to the barrier; therefore, eliminating 

the need for imported water.

Water Quality and Treatment 

Technology 

Water quality from the LCWRP is essentially the same 

as the LBWRP. Comparison of average influent and 

effluent water quality parameters from 2010 is shown 

in Table 1. 

Table 1 Influent and effluent water quality from 2010

Parameter

Influent Product

LBWRP LCWRP LVLWTF

TOC (mg/L) 6.7 7.5 0.44

Turbidity (NTU) 0.48 0.50 0.07

TDS (mg/L) 703 787 83

pH (SU) 7.9 7.9 8.12

TN (mg/L) 9 9.3 2.05

Nitrate (mg/L as N) 6 5.3 1.74

Ammonia (mg/L) 1.5 2.0 0.22

NDMA (ng/L) 291 296 4.9

1,4 Dioxane (ug/L) RNR 2.55 ND

The treatment processes used at the LVLWTF follow 

the “California Model” for indirect potable reuse, using 

microfiltration (MF), reverse osmosis (RO), and 

ultraviolet (UV) (Figure 1). Facilities are located on a 

site adjacent to the LBWRP shown in Figure 2.

Microfiltration System. The existing MF system will 

be expanded to provide 8.35 mgd (370 L/s) of filtrate. 

The expanded system will have 6 MF racks with 100 

modules per rack and is sized for a flux rate of 35 

gallons per square foot per day (gfd) (58 L/m2

/hr) and 

a recovery rate of about 95 percent. Maintenance 

Figure 1

LVLWTF process flow diagram (Photo credit: CDM 

Smith 2011)

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

cleans can be performed daily while clean-in-place 

protocols are performed monthly. Half of the existing 

MF system will be modified to treat MF backwash from 

expanded MF equipment; while the remaining modules 

will be moved to the new MF racks.

MF Backwash Treatment. MF backwash will be 

treated with a DAF and MF membranes as shown in 

Figure 3. Due to this level of treatment and the fact 

that no virus removal credit is being taken for the MF, 

0.42 mgd (18 L/s) of water can be used as influent to 

the RO system.

Reverse Osmosis System. The current two stage RO 

system will be expanded to produce 8 mgd (350 L/s) of 

RO permeate at a flux rate of 12.2 gfd (20.3 L/m2

/hr). 

The two stage RO system will be supplemented with a 

third stage to increase the overall RO recovery to 

approximately 92 percent (Figure 4).

UV-A System. Additional equipment is being added to 

the UV system during the expansion to increase 

capacity to 8 mgd (350 L/s). Hydrogen peroxide will 

also be added to provide advanced oxidation. The 

system will provide 1.62-log to 2-log removal of NDMA 

and 0.5-log 1,4-dioxane removal. 

Appurtenances. Finished water pumps deliver water 

to the barrier. Calcium chloride and sodium hydroxide 

will be added to provide minerals and pH control to 

stabilize the water. A chloramine residual will be 

required for the barrier injection. Plant wastes, 

including the RO concentrate, are conveyed to the 

local trunk sewer for further treatment downstream 

prior to discharge to the ocean outfall.

Project Funding and Management 

Practices 

A Federal Title XVI grant and California Proposition 84 

grant provided partial funding for the design and 

construction of the LVLWTF, with the remaining 

funded by WRD via debt financing. Operation of the 

LVLWTF is contracted to the Long Beach Water 

Department (LBWD). Influent water is obtained from 

the LBWD and the LACSD. The Alamitos Barrier is 

owned and operated by the LACDPW.

Institutional/Cultural Considerations 

The expansion is similar to the existing facility except 

the waste flow is limited to 760,000 gpd (2,900 m3

/d). 

The LVLWTF expansion provides the additional 5 mgd 

(220 l/s) of treatment capacity without increasing 

waste flows to sewer. To accomplish this, backwash 

from the MF system will be treated and used while a 

third stage will be added to the RO to increase the 

recovery. The expanded plant will have an overall 92 

percent water recovery rate.

Successes and Lessons Learned

The LVLWTF was the first indirect potable reuse plant 

in California to be designed to remove NDMA while the 

expansion construction may be the first permitted 

under the California Recycled Water Recharge 

regulations.

Figure 4

Three stage RO system (Photo credit: SPI 2011)

Figure 3

MF and MF backwash treatment systems (Photo credit: 

CDM Smith 2012)

Figure 2

LVLWTF site (Photo credit: CDM Smith 2011)

D-54
2012 Guidelines for Water Reuse

Use of Pasteurization for Pathogen Inactivation for 

Ventura Water, California

Author: Andrew Salveson, P.E. (Carollo Engineers)

US-CA-Pasteurization

Project Background or Rationale 

Pasteurization, discovered by Louis Pasteur in 1864, is 

a process of applying heat to inactivate pathogenic or 

spoilage microorganisms. The process has since 

become standard practice in the food industry and has 

recently become an accepted practice in sewage 

sludge processing, to achieve Class A Biosolids 

standards. This technology has the ability to be used 

in sewage sludge processing as well as treated 

wastewater disinfection. The use of pasteurization as a 

disinfection technology was originally demonstrated to 

the California Department of Public Health (CDPH) at 

the City of Santa Rosa, California’s, Laguna 

Wastewater Reclamation Plant. A demonstration scale 

system (Figure 1) was built by Pasteurization 

Technology Group for Ventura Water at the Ventura 

Water Reclamation Facility in Ventura, Calif.

Treatment Technology 

Pasteurization is based on thermal inactivation of 

microorganisms. This process 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 protection 

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 parameters. The 

most useful information within the literature is the 

demonstration of the relative sensitivities to heat for 

various pathogens and indicator organisms. The 

particular temperature and contact time required for 

bacterial and viral disinfection of treated wastewater is 

presented in Figures 2 and 3, respectively (adapted 

from Salveson [2007]).

Figure 3

Disinfection of MS2 Coliphage in treated effluent 

(Salveson, 2007)

Figure 2

Disinfection of total coliform in treated effluent 

(Salveson, 2007)

Figure 1

400 gpm Wastewater Pasteurization Demonstration 

System in Ventura California (Photo credit: Greg 

Ryan, Pasteurization Technology Group)

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

Moce-Llivina et al. (2003) investigated pasteurization 

of seeded bacteriophages and enteroviruses in raw 

sewage and tested the effect of pasteurization at 140 

degrees F (60 degrees C) for 30 minutes. They found 

that MS2 was the most heat sensitive coliphage and 

that somatic coliphages and phages infecting B. 

fragilis were the most resistant. Enteroviruses were 

significantly more heat sensitive than any of the 

phages, with poliovirus being the most heat sensitive. 

Based upon this and other work, primarily the testing 

in Santa Rosa, Calif., the CDPH determined that a 4-

log reduction in a seeded MS2 coliphage test 

conservatively provided equivalent disinfection to 5-log 

reduction of poliovirus. Pasteurization to this rigorous 

reclaimed water standard was 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). The detailed research is summarized in 

Salveson et al. (2011). 

The CDPH approved pasteurization to meet the 

stringent “tertiary recycled water criteria” for coliform 

and virus reduction based upon a minimum contact 

time of 10 seconds at or above 179 degrees F (81.6 

degrees C). Figures 2 and 3 illustrate disinfection 

performance for bacteria and virus, respectively in 

filtered and unfiltered effluents. This data suggests that 

water quality does play a role in pasteurization 

disinfection kinetics, particularly with regard to coliform 

disinfection.

Economic and Management Practices 

The economic value of pasteurization is favorable 

when waste heat can be captured and transferred for 

disinfection. The goal of pasteurization is to keep all 

heat in a loop, continuously transferring the heat in the 

disinfected water with the cool undisinfected water. To 

accomplish this, a series of carefully designed heat 

exchangers are used. The ongoing demonstration 

testing in Ventura, Calif., shows that all but two 

degrees of heat is continuously transferred, resulting in 

only a minimal need for continuous heat addition. 

Example sources of waste heat include exhaust heat 

from a turbine fueled by natural gas, digester gas, hot 

water, or a combination of the waste heats. The 

economics of pasteurization appear extremely 

favorable where power costs are high. In Ventura, 

Calif., pasteurization costs project to be millions of 

dollars less than other alternative disinfection 

technologies. These economics (summarized in 

Salveson et. al, 2011) led to the demonstration testing 

in Ventura. Pasteurization Technology Groups has a 

worldwide patent for the process.

References

Salveson, A., Ryan, G., Goel, N. (2011) Pasteurization – Not 

Just for Milk Anymore. Water Environment and Technology; 

March 2011, p. 42-45.

Salveson, A. (2007) RP&P Wastewater Pasteurization 

System Validation Report. Technical Report by Carollo 

Engineers Submitted to the CDPH; July 2007.

Moce-Llivina, L., Muniesa, M., Pimenta-Vale, H., Lucena, F., 

and Jofre, J. (2003). Survival of Bacterial Indicator Species 

and Bacteriophages after Thermal Treatment of Sludge and 

Sewage. Applied and Environmental Microbiology, Mar. 

2003, p. 1452-1456.

D-56
2012 Guidelines for Water Reuse

California State Regulations

Author: James Crook, PhD, P.E., BCEE (Water Reuse Consultant) 

US-CA-Regulations

Project Background or Rationale 

The state of California has a long history of water 

reuse and regulatory activity and was the first agency 

to develop regulations specifically directed at the safe 

use of reclaimed water. The evolution of water 

reclamation and reuse criteria truly began in California, 

and the philosophy and rationale behind that state’s 

regulations have pervaded many other regulations 

around the world. 

Regulatory Authority

The principal state regulatory agencies involved in 

water recycling in California are the California 

Department of Public Health (CDPH), the California 

State Water Resources Control Board (SWRCB), and 

the nine Regional Water Quality Control Boards 

(RWQCBs) (Crook, 2010). In 1991, the SWRCB and 

RWQCBs were brought together with five other state 

environmental protection agencies under the newly 

crafted California Environmental Protection Agency 

(Cal/EPA). 

The nine semi-autonomous RWQCBs are divided by 

regional boundaries based on major watersheds. Each 

RWQCB makes water quality planning and regulatory 

decisions for its region. The SWRCB is generally 

responsible for setting statewide water quality policy 

and considering petitions contesting RWQCB actions. 

CDPH has statutory authority in two areas with respect 

to direct potable reuse. It regulates public water 

systems (drinking water purveyors) and develops and 

adopts water recycling criteria. 

History of Regulation Development 

At the turn of the 20th century, California had at least 

20 communities using either raw or settled sewage for 

agricultural irrigation. The earliest reference to a public 

health viewpoint on water quality requirements in 

California appeared in the California State Board of 

Health Monthly Bulletin dated February 1906, in which 

it was stated:

1906: “Oxnard is installing a septic tank 

system of sewage disposal, with an outlet in 

the ocean. Why not use it for irrigation and 

save the valuable fertilizing properties in 

solution, and at the same time completely 

purify the water? The combination of the 

septic tank and irrigation seems the most 

rational, cheap, and effective system for this 

State.” (Ongerth and Jopling, 1977) 

Therefore, the first water quality requirement for 

reclaimed water use in California was septic tank 

treatment.

Official control on the sewage irrigation of crops began 

in 1907, with the publication of State Board of Health's 

April 1907 Bulletin specifying that local health 

authorities "watch irrigation practices" and not allow 

use of "sewage in concentrated form and sewagepolluted water...to fertilize and irrigate vegetables 

which are eaten raw, and strawberries." (Crook, 2002)

The first standards adopted by the State Board of 

Health in 1918, titled Regulation Governing Use of 

Sewage for Irrigation Practices (California State Board 

of Health, 1918), prohibited the use of raw sewage for 

crop irrigation and limited the use of treated effluents 

to irrigation of nonfood crops and food crops that were 

cooked before being eaten or food crops that did not 

come in direct contact with the wastewater. Garden 

crops of the type that are cooked before being eaten 

could be irrigated if the application of effluent was not 

made within 30 days of harvest. The regulations 

provided several exemptions, such as permitting 

irrigation of melons if the sewage did not come in 

contact with the vine or product and irrigation of treebearing fruit or nuts if windfalls or products lying on the 

ground were not harvested for human consumption. 

The regulations were revised in 1933 and renamed 

Regulations on the Use of Sewage for Irrigating Crops

(CDPH, 1933). These regulations prohibited the use of 

raw sewage for crop irrigation and prohibited the use 

of sludge as a fertilizer for growing vegetables, garden 

truck, or low growing fruits or berries unless the sludge 

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was rendered innocuous. It prohibited the use of 

settled or undisinfected sewage effluent for the 

irrigation of the same type of crops and for the 

irrigation of orchards or vineyards during seasons in 

which windfalls or fruit lie on the ground. Irrigation of 

fodder, fiber, or seed crops with settled or 

undisinfected sewage was allowed, but milk cows 

could not be pastured on the land that was moist with 

sewage. The regulations exempted restriction of 

wastewater for the irrigation of garden truck crops 

eaten raw if the wastewater was well oxidized, 

nonputrescible, and reliably disinfected or filtered to 

meet a bacterial standard approximately the same as

the then-current drinking water standard. Disinfection 

reliability was emphasized in that two or more 

chlorinators, weighing scales, reserve supply of 

chlorine, twice daily coliform analyses, and records 

were required. It was noted that the revisions were

made because of an expressed interest by the Los 

Angeles Chamber of Commerce and others in the 

nearby communities to conserve water, to provide 

employment for fieldworkers in contemplated truck 

gardens, and to save beaches (Ongerth and Jopling, 

1977). The 1933 standards marked the first 

appearance of cross connection control regulations. 

Cross connections between wastewater and domestic 

water supply pipelines were prohibited, and signs 

warning against drinking the water were specified on 

pipes and appurtenances that contain wastewater.

The 1933 regulations continued in effect until passage 

of the Water Pollution Act of 1949 eliminated the 

permit system that constituted the statutory basis for 

the regulation (Ongerth and Jopling, 1977). They were 

re-issued without change in 1953 as Regulations 

Relating to Use of Sewage for Irrigating Crops (CDPH, 

1953).

The number of water reuse projects increased 

dramatically in the 1960s, and it became necessary to 

develop water reclamation standards for various types 

of use. In 1967, a state legislative committee reported 

that legislation relating to the use of reclaimed 

wastewater was needed to protect public health and 

that the CDPH should be required to establish 

statewide contamination standards. The committee 

recommended that the RWQCBs establish 

requirements for the use of reclaimed water that are in 

conformity with the statewide contamination standards. 

These recommendations resulted in revisions to the 

California Water Code in 1967, which gave the CDPH 

the authority and responsibility to establish reclamation 

criteria and gave the RWQCBs the responsibility to 

enforce the criteria (California State Water Resources 

Control Board, 1967).

As a result of the above-mentioned legislation, more 

comprehensive regulations were enacted in 1968 that 

were directed mainly at the control of disease agents. 

These Statewide Standards for the Safe Direct Use of 

Reclaimed Water for Irrigation and Impoundments

(CDPH, 1968) included treatment and quality 

requirements intended to assure that the use of 

reclaimed water for the applications specified in the 

regulations would not impose undue risks to the public 

health.

Several studies conducted by the Department of 

Health in the late 1960s and early 1970s indicated a 

record of poor reliability at wastewater treatment plants 

(Crook, 1976; California Department of Health, 1973). 

At the request of the Department of Health, a 

modification in state law authorized the Department of 

Health to establish regulations on treatment reliability. 

The 1968 standards specified levels of constituents of 

reclaimed water and were revised in 1975 to include 

treatment reliability requirements, then renamed 

Wastewater Reclamation Criteria (California 

Department of Health Services, 1975). There have 

been two subsequent revisions to the criteria, one in 

1978 that added general requirements for groundwater 

recharge and differentiated between different types of 

landscape irrigation (California Department of Health 

Services, 1978). Research and demonstration studies 

conducted in the late 1970s and 1980s, along with 

advances in treatment technology and a need to 

include requirements for additional types of reuse, 

resulted in a protracted effort to revise the 1978 

criteria. This effort, begun in 1988, culminated in 

adoption of a new set of criteria in 2000. These Water 

Recycling Criteria include requirements for several 

new applications of reclaimed water, modify some of 

the treatment and quality requirements, prescribe 

requirements for dual water systems, include cross 

connection control requirements, and include use area 

requirements that formerly were issued as guidelines 

(California Department of Health Services, 2000). In 

conformance with terminology in the California Water 

Code, the word “reclaimed” was replaced with 

“recycled” and “reuse” was replaced with “recycling” in 

all regulations. 

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Additional information on the decision-making and 

rationale that went into the details of the 1968, 1975, 

1978, and 2000 updated water reuse regulations in 

California is available in Crook (2002). California has 

used advisory committees, public meetings, and other 

means of communication with a broad spectrum of 

interested parties, including waste dischargers, 

regulatory agencies, and potential users over the 

years during development of its water reuse 

regulations in order to arrive at a proper balance of 

realistic and workable standards that ensure an 

acceptable level of public health protection.

Recycled Water Policy

In 2009 the SWRCB adopted a Recycled Water Policy 

(California State Water Resources Control Board, 

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 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.” 

The policy also 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 state-wide objectives to 

achieve sustainable water resource management.

The SWRCB included a provision in the 2009 

Recycled Water Policy to establish a Science Advisory 

Panel to provide guidance for future development of 

monitoring programs that assess potential threats from 

constituents of emerging concern (CECs) where 

recycled water is used for various water recycling 

applications. Recycling applications could include 

urban landscape irrigation and indirect potable reuse 

via surface water augmentation as well as drinking 

water aquifer recharge using surface spreading or 

subsurface injection. The Science Advisory Panel’s 

report, entitled “Monitoring Strategies for Chemicals of 

Emerging Concern in Recycled Water” was published 

in 2010 (California State Water Resources Control 

Board, 2010). The SWRCB subsequently released 

draft amendments to the Recycled Water Policy 

(California State Water Resources Control Board, 

2012) in response to the Science Advisory Panel’s 

report that added many of the Panel’s 

recommendations related to monitoring strategies for 

CECs in recycled water. 

Proposed Indirect Potable Reuse 

Regulations 

CDPH first began crafting comprehensive regulations 

for indirect potable reuse (IPR) via groundwater 

recharge by surface spreading and direct injection into 

potable water supply aquifers more than two decades 

ago. The most recent version of the draft regulations 

(California Department of Public Health, 2011) was 

released in November 2011. The draft regulations 

include (among other criteria) requirements for 

treatment unit processes, water quality, dilution, 

source control programs, response time between 

treatment and extraction of the water for potable 

purposes, monitoring wells, and monitoring for 

indicators, surrogates, and selected CECs. They are 

scheduled to be finalized and adopted by the end of 

2013. Upon adoption, the groundwater recharge 

regulations will be included in the CDPH Water 

Recycling Criteria. 

References

California Department of Health. 1973. Development of 

Reliability Criteria for Water Reclamation Operations.

California Department of Health Services, Water Sanitation 

Section, Berkeley, California.

California Department of Health Services. 1975. Wastewater 

Reclamation Criteria. California Administrative Code, Title 

22, Division 4, California Department of Health Services, 

Water Sanitation Section, Berkeley, California.

California Department of Health Services. 1978. Wastewater 

Reclamation Criteria. California Administrative Code, Title 

22, Division 4, California Department of Health Services, 

Sanitary Engineering Section, Berkeley, California.

California Department of Health Services. 2000. Water 

Recycling Criteria. California Code of Regulations, Title 22, 

Division 4, Chapter 3. California Department 

of Health Services, Sacramento, California. Retrieved on 

August 30, 2012 from

<http://www.cdph.ca.gov/certlic/drinkingwater/Documents/La

wbook/RWregulations-01-2009.pdf>. 

California Department of Public Health. 1933. Special 

Bulletin No. 59: Regulations on Use of Sewage for Irrigating 

Crops. State of California Department of Public Health, 

Sacramento, California.

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California Department of Public Health. 1953. Regulations 

Relating to Use of Sewage for Irrigating Crops. California 

Administrative Code, Title 17, Chapter 5, Subchapter 1, 

Group 7, State of California Department of Public Health, 

San Francisco, California.

California Department of Public Health. 1968. Statewide 

Standards for the Safe Direct Use of Reclaimed Water for 

Irrigation and Recreational Impoundments. California 

Administrative Code, Title 17, Group 12, California 

Department of Public Health, Berkeley, California.

California Department of Public Health. 2011. Groundwater 

Replenishment Reuse DRAFT Regulation. California 

Department of Public Health, Drinking Water Program, 

Sacramento, California. Retrieved on August 30, 2012 from 

<http://www.cdph.ca.gov/certlic/drinkingwater/Documents/Re

charge/DraftRechargeReg-2011-11-21.pdf>. 

California State Board of Health. 1918. Regulations 

Governing Use of Sewage for Irrigation Purposes. California 

State Board of Health, Sacramento, California.

California State Water Resources Control Board. 1967. 

Wastewater Reclamation and Reuse Law. California Water 

Code, Chapter 6, Division 7, California State Water 

Resources Control Board, Sacramento, California.

California State Water Resources Control Board. 

2009. Water Recycling Policy. California State Water 

Resources Control Board, Sacramento, California.

Retrieved on August 30, 2012 from 

<http://www.waterboards.ca.gov/water_issues/programs/wat

er_recycling_policy/index.shtml>. 

California State Water Resources Control Board. 2010. Final 

Report: Monitoring Strategies for Chemicals of Emerging 

Concern (CECs) in Recycled Water. Recommendations of a 

Science Advisory Panel, State Water Resources Control 

Board, Sacramento California.

California State Water Resources Control Board. 2012. 

Draft Revised Water Recycling Policy. State Water 

Resources Control Board, Sacramento California. Retrieved 

on August 30, 2012 from

<http://www.waterboards.ca.gov/water_issues/programs/wat

er_recycling_policy/docs/amendment_docs/draft_rwp_clean.

pdf>. 

Crook, J. 1976. Reliability of Wastewater Reclamation 

Facilities. State of California Department of Health, Water 

Sanitation Section, Berkeley, California.

Crook, J. 2002. The Ongoing Evolution of Water Reuse 

Criteria. In: Proceedings of the AWWA/WEF 2002 Water 

Sources Conference (CD-ROM), January 27-30, 2002, Las 

Vegas, Nevada.

Crook, J. 2010. Regulatory Aspects of Direct Potable Reuse 

in California. White paper published by the National Water 

Research Institute, Fountain Valley, California.

Ongerth, H.J., and W.F. Jopling. 1977. Water Reuse in 

California. In: Water Renovation and Reuse, pp.219-256, 

Academic Press, Inc., New York, New York.

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West Basin Municipal Water District: 

Five Designer Waters

Author: Shivaji Deshmukh, P.E. (West Basin Municipal Water District)

US-CA-West Basin

Project Background or Rationale 

West Basin Municipal Water District (West Basin) is a 

special district of the State of California and an 

innovative public agency that provides drinking and 

recycled water to its 185-square-mile (480-km2

) 

service area located in coastal Los Angeles County. 

West Basin purchases imported water from the 

Metropolitan Water District of Southern California and 

wholesales the imported water to cities, water 

agencies, and private water companies in its service 

area. In order to reduce the dependence on imported 

water supplies, West Basin developed a world 

renowned recycled water program that currently 

produces more than 30 million gallons per day (1,300 

L/s) of “designer” recycled water. West Basin recently 

began a new program, Water Reliability 2020, to 

expand its portfolio of locally produced water to ensure 

water supply reliability for future residents and 

businesses. This program is designed to reduce the 

dependence on imported water by increasing the 

amount of water conserved and produced locally. By 

2020, West Basin will double water recycling and 

water conservation programs and include 

environmentally responsible ocean-water desalination 

as part of the water supply portfolio.

Capacity and Type of Reuse 

Application 

West Basin’s Water Recycling Facility is named the 

Edward C. Little Water Recycling Facility (ECLWRF) 

(Figure 1) to honor the 6-term commitment made to 

West Basin and our constituents by Director Edward 

C. Little. The ECLWRF is a world-class, state-of-theart facility that is the largest of its type in the world. 

Working with customers such as Toyota, Honda, 

Chevron, Goodyear, California State University, Home 

Depot Center, Raytheon, Los Angeles Air Force Base, 

and Marriott, West Basin has built a unique water 

recycling program with the capacity to expand 

throughout our service area. 

This facility produces more than 30 million gallons of 

recycled water every day for over 380 customer sites. 

Uses of recycled water include irrigation, boiler feeds, 

cooling towers, street sweepers, and injection into 

seawater barriers to provide protection for local 

groundwater supplies from saltwater intrusion by the 

ocean. This water purification facility produces five 

types of “designer” waters to serve specific customer 

needs for various uses, including golf courses, 

professional soccer fields, street sweeping, restrooms, 

boilers, cooling towers and other commercial, 

municipal and industrial uses. All five types of 

“designer” water meet the treatment and water quality 

requirements specified in the California Department of 

Public Health’s Water Recycling Criteria and permitted 

by the Los Angeles Regional Water Quality Control 

Board. “Designer” Waters that are fit for various 

purposes include:

1. Tertiary Water: Secondary treated wastewater 

that has been filtered and disinfected for a wide 

variety of industrial and irrigation uses

Figure 1

The Edward C. Little Water Recycling Facility is 

located in El Segundo, California

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2. Nitrified Water: Tertiary water that has been 

nitrified to remove ammonia for industrial cooling 

towers. 

3. Reverse Osmosis Water: Secondary treated 

wastewater by microfiltration, followed by reverse 

osmosis (RO) and UV disinfection and advanced 

oxidation using hydrogen peroxide for 

groundwater injection, which is superior to state 

and federal drinking water standards.

4. Pure Reverse Osmosis Water: Secondary 

treated wastewater that has undergone microfiltration and RO can be used for low-pressure 

boiler feed water. 

5. Ultra-Pure Reverse Osmosis Water: Secondary 

treated water that has undergone micro-filtration 

and two passes through RO for high-pressure 

boiler feed water.

In addition to providing recycled water for commercial 

and industrial uses, high-quality recycled water 

produced by West Basin is injected into the 

groundwater basin to prevent seawater intrusion into 

the local aquifers. The West Coast Barrier is a series 

of injection wells positioned between the ocean and 

the groundwater aquifer. These wells inject water 

along the barrier to ensure that the water level near 

the ocean stays high enough to prevent the seawater 

from seeping into the aquifer. In April 2009, West 

Basin and the Water Replenishment District of 

Southern California (WRD) signed an agreement to 

increase the amount of water supplied to the barrier by

100 percent by 2012. 

Water Quality Standards and 

Treatment Technology 

With five distinct “designer” waters, many water quality 

requirements exist for West Basin’s recycled water 

program. While each has established water quality 

guidelines, the most regulated is recycled water for 

injection into the groundwater basin. This quality 

meets and exceeds all potable drinking water 

guidelines. In order to improve the flux through the 

microfiltration process of this treatment train, West 

Basin will soon implement the use of ozone as a 

pretreatment step prior to this filtration process. 

Figure 2 shows the heart of the treatment process, 

reverse osmosis.

Project Funding and Management 

Practices 

The recycled water program is funded though capital 

investment from major customers, state and federal 

grants, local supply subsidies, and recycled water 

rates. West Basin maintains a relatively small work 

force. Its operational model includes contract 

operations for the treatment plant and the distribution 

system. It also has employed various project deliver 

methods including design-build.

Institutional/Cultural Considerations 

The focus of West Basin’s outreach is its award 

winning Water Reliability 2020 program. The district 

conveys news about water supply through multiple 

mediums including community events, media affairs, 

conservation classes and the district’s website. West 

Basin offers free conservation classes, classroom 

education and facility tours to more than 10,000 

people each year. 

Successes and Lessons Learned

West Basin has been a leader in application of 

technology to produce water for indirect potable reuse. 

Some of the technology successes have included 

application of microfiltration as a pretreatment step for 

reverse osmosis as well as implementation of low 

pressure, high intensity UV disinfection for disinfection 

and advanced oxidation of indirect potable water, 

leading the way for other agencies to follow suit with 

similar treatment processes. Once complete later this 

year, West Basin will be one of the first to use ozone 

as a pretreatment before microfiltration to improve 

Figure 2 water quality.

Reverse osmosis treatment at the ECLWRF

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Denver Zoo

Authors: Abigail Holmquist, P.E. (Honeywell); Damian Higham (Denver Water); 

and Steve Salg (Denver Zoo)

US-CO-Denver Zoo

Project Background

Denver Zoo is one of the most popular cultural 

institutions in Colorado and is widely recognized as 

one of the nation’s premier zoos. Denver Zoo’s 

mission to “secure a better world for animals through 

human understanding” embraces not only worldwide 

wildlife habitat preservation, but local conservation as 

well. One practical way Denver Zoo is achieving its 

goals is through water conservation efforts and use of 

recycled water.

Capacity and Type of Reuse 

Application 

Through a partnership with Denver Water, Denver Zoo 

has successfully reduced its water consumption by 42 

percent over the past decade. Added to this 

accomplishment is implementation of a recycled water 

system. Denver Zoo is unique in that it uses recycled 

water not only for irrigation, but for enclosure washdown and animal swimming pools (Figure 1). Denver 

Zoo currently uses approximately 2 million gallons 

(7600 m3

) of recycled water annually. At build-out of its 

master plan, Denver Zoo hopes to expand recycled 

water use to 75 percent of its total water consumption, 

representing over 134 million gallons (609,000 m3

) of 

recycled water per year. 

Water Quality Standards and 

Treatment Technology 

The Colorado Department of Public Health and 

Environment regulates recycled water through 

Regulation 84, which sets forth treatment standards, 

allowable uses and water quality standards for 

different water categories. Category 3 water is 

produced by the reclamation plant and has an E. coli 

maximum of 25 percent detectable in any given month 

and 126 cfu/100ml in any sample. Turbidity results 

must not exceed 5 NTU in more than 5 percent of 

samples in a month and 3 NTU as a monthly average. 

Additional treatment targets for ammonia and 

phosphorous at Denver Water’s recycling plant were 

developed in cooperation with industrial customers to 

ensure that recycled water quality would be suitable 

for needs. Typical recycled water quality parameters 

are shown in Table 1. 

Institutional/Cultural Considerations 

As the animals are one of the primary assets of 

Denver Zoo, it was paramount that their safety be top 

priority when considering recycled water uses and 

implementation strategies. Veterinarians examined the 

chemical composition of Denver Water’s recycled 

water and determined which animals should be 

allowed to come into contact with or consume recycled 

water.

Public and worker education programs are also 

important to impart the value of recycled water use, as 

well as the hazards associated with its use. These 

messages are communicated to the public with 

signage at the main entrance to Denver Zoo and in 

use areas with public access (Figure 2). Workers 

undergo annual training provided by Denver Water 

and by Denver Zoo ensuring they work with recycled 

water in a manner that will protect the animals, the 

public and coworkers.

Figure 1

Predator Ridge Exhibit in Denver Zoo (Photo credit: 

Denver Zoo)

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Table 1 Typical water quality parameters

Parameter Units Typical Range

Alkalinity, as CaCO3 mg/L 50-150

Ammonia as N mg/L 0-0.4

Boron mg/L 0.2-0.4

Calcium mg/L 40-70

Chloride mg/L 65-170

Chlorine, Total mg/L 1.5-4.0

Iron mg/L 0.05-0.6

Magnesium mg/L 5-20

Manganese mg/L 0.003-0.08

Nitrate + Nitrite as N mg/L 5-30

Nitrate as N mg/L 5-20

Nitrite as N mg/L 0.01-0.05

Ortho Phosphorous, 

Dissolved as P mg/L 0.04-0.3

pH SU 6-8 

Phosphorous, as P mg/L 0.04-0.4

Potassium mg/L 10-20

Sodium mg/L 90-200

Specific Conductance mg/L 360-1250

Sulfate mg/L 80-250

Temperature 0C 10-30

Total Coliform MPN/

100mL <1.0

Total Kjeldahl Nitrogen mg/L 0.2-2 

Total Organic Carbon mg/L 4-8 

Successes and Lessons Learned

Denver Zoo has saved $14,700 on water during the 

infancy of their program, and with water use expected 

to nearly quadruple during the next two years, that 

trend should continue. Recycled water use has also 

contributed to Denver Zoo being named the greenest 

zoo in the nation by the Association of Zoos and 

Aquariums.

While the use of recycled water is beneficial to the zoo 

and Denver Water, the conversion of a complicated 

system to recycled water can be challenging. Even 

when only licensed plumbers are working on the 

system, there is still room for error. In 2006, while 

conducting a cross-connection control audit, Denver 

Water discovered an uncontrolled cross-connection on 

the potable system. Fortunately, this connection was 

not feeding water used for consumption, so the risk to 

the public was minimal. 

 

“The addition of recycled water has resulted 

in significant opportunities for Denver Zoo. 

The ability to reuse our natural resources fits 

perfectly with Denver Zoo’s core values of 

conservation. With close to 2 million visitors 

annually, we can help spread the message 

of recycled water to the community. Plus, the 

money we save by switching to recycled 

water enables us to allocate some of those 

funds toward animal management programs 

and other important conservation efforts.”

—Steve Salg (Denver Zoo Project Manager) 

Figure 2

Public education signage (Photo credit: Denver Zoo)

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2012 Guidelines for Water Reuse

Denver Water

Authors: Abigail Holmquist, P.E. (Honeywell); Mary Stahl, P.E. (AECOM); and 

Steve Price, P.E. (Denver Water) 

US-CO-Denver

Project Background

The population along the Front Range of Colorado is

expected to increase significantly in the next few 

decades; recent statewide reports project the Denvermetro population to double by 2050, fueling the need 

for additional renewable water supplies. Water use in 

this region includes significant irrigation; Denver is in 

an arid region (less than 20 in [50 cm] of annual 

rainfall) with warm summers. Amenities such as parks, 

sports fields, and golf courses require irrigation. 

Denver Water has operated a reclaimed water system 

since 2004 and will expand its system over the next 

decade to help meet demands.

Water rights are critical considerations for reuse 

projects in Colorado because local water law follows a 

first-in-time, first-in-right allocation; this is also known 

as the “prior appropriation principle.” It typically 

prohibits rainwater harvesting and graywater use. 

Because the majority of the population in Colorado 

lives on the east side of the state, and the majority of 

the water originates on the West Slope, many water 

providers have a long history of diverting water out of 

its river basin to supply water where the demand is 

located. Once water is diverted out of its basin, it can 

typically be reused “to extinction.” Recycling water 

helps Denver Water fulfill the 1955 Blue River Decree, 

which gave Denver Water the ability to reuse water 

that had been diverted out of this basin on the West 

Slope.

Capacity and Type of Reuse 

Application 

Many of Denver Water’s users do not require high 

quality such as provided for cooling systems and 

irrigation. Thus, reclaimed water for these uses should 

match the right water quality for the right use. In 2004, 

Denver Water commissioned a 30 mgd (1,310 L/s) 

reclaimed water plant to supply water for non-potable 

uses. Current demand for reclaimed water varies 

between 5,000 and 6,000 acre-feet (6 to 7.5 million 

m3

) annually, depending on precipitation and weather 

conditions. Current uses include cooling water for a 

large electric utility; irrigation of parks, golf courses, 

and schools; and operations at the Denver Zoo. 

The water recycling plant is expandable to 45 mgd 

with an ultimate goal for Denver Water to shift 17,500 

ac-ft (21.5 MCM) per year of demand to the reclaimed 

water system. During the 2010 irrigation season, 

Denver Water served a total of 29 customers. A 

recently completed master plan identified over 300 

additional customers that will need to connect to the 

system to reach the reuse goal of 17,500 ac-ft (21.5 

MCM) per year. 

Water Quality and Treatment 

Technology 

The reclaimed water treatment plant uses biological 

activated filtration, alum coagulation/flocculation/ 

sedimentation, single media filtration, chlorine-based 

disinfection. Denver Water produces reclaimed water 

that meets Category 3 standards of Colorado 

Department of Public Health and Environment 

Regulation 84 that must meet the following 

requirements:

 No detects of E. coli in at least 75 percent of 

samples in a calendar month, and less than 126 

cfu/100 mL in a single sample 

 Turbidity, NTU: Not to exceed 3 NTU as a 

monthly average and not to exceed 5 NTU in 

more than 5 percent of the individual samples 

during any calendar month

Since Denver Water has implemented a reclaimed 

water program, interpretation of the state regulations 

has changed directly impacting the ability of certain 

customers to use reclaimed water, and how Denver 

Water operates its system. These issues are currently 

being addressed through a statewide update to the 

regulations and on an individual customer basis. 

Additionally, Denver Water has conducted studies 

related to commercial, industrial, and landscape 

operations to identify options for current and future 

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customers to successfully use reclaimed water at their 

facilities.

Project Funding and Management 

Practices 

Denver Water has funded the reclaimed water system 

via revenues from water rates, system development 

charges, and bonds. Water rates for all customers 

include funding the reclaimed water treatment plant 

because it is considered a source of new water supply. 

This methodology results in reclaimed water rates that 

are economically attractive for customers compared to 

potable water rates. Water rates for different water 

service are shown in Figure 1. 

Denver Water’s rate structures include a monthly 

service charge and a volume rate structure that varies 

by customer class. The volumetric rate structures 

include uniform, seasonal, and inclining blocks. Rate 

structures (Figure 2) are applied to each class and are 

designed to encourage efficient water use.

Denver Water has developed policies to address 

different approaches to providing reclaimed water: 

 Customer requests a conversion: Customer 

pays all conversion costs, including main 

extensions, service lines and point of service 

upgrades 

 Denver Water requires a customer to convert: 

Denver Water pays all conversion costs, 

including main extensions and service lines, up 

to the first valve on the property 

 New development in reclaimed water service 

area: Developer installs all infrastructures 

necessary for reclaimed water service 

Institutional and Cultural 

Considerations 

Until the reclaimed water system began operating in 

2004, Denver Water had only been responsible for 

operating raw and potable water systems. Thus, the 

water reclamation plant is staffed by drinking water 

operators and operations are strongly focused on 

maintaining internal water quality goals that are more 

stringent than those required by regulations and 

Denver Water has never violated reclaimed water 

quality criteria. CDPHE’s Regulation 84 requires 

annual reports, training and inspections that require 

customers to employ best management practices and 

employee education. Denver Water personnel have an 

on-going relationship with reclaimed water customers 

that includes significantly more communication than is 

typical between a utility and its customers.

Successes and Lessons Learned

In general, the reclaimed water program received 

support when it was implemented. Denver Water has 

also implemented a youth education program that 

includes sixth grade curriculum covering the overall 

water cycle, including reuse. As part of this program, 

school children and teachers tour the reclaimed water 

facility each year. The program has achieved great 

success including the adoption of reuse at the Denver 

Figure 2

Relative water rates by class of service

Figure 1

Water rates structure 

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Zoo and the electric company. Two Denver Water 

customers, the Denver Zoo and Common Ground Golf 

Course, have received awards from the WateReuse 

Association in recognition of their adoption of 

reclaimed water. In areas where reclaimed water 

service is available, some customers are now 

beginning to pay their own costs to connect to the 

reclaimed water due to long-term water savings and 

overall alignment with sustainability goals. 

While the Denver Water reclaimed water program has 

been successful, there remain opportunities to address 

challenges that have the potential to impact the 

program. The reclaimed water system is a branched 

rather than a looped system, which creates challenges 

in providing water supply during planned/unplanned 

outages. Additionally, there is still limited infrastructure 

available for customers to connect to the system, 

prohibiting some customers from connecting as soon 

as desired. Customers are continuing to conserve 

water, which has resulted in reclaimed water being 

available to more customers than originally anticipated 

and these decreased customer consumption patterns 

are anticipated to result in a greater number of 

customer connections to the reclaimed water system 

being required to meet the overall recycling goal of 

17,500 ac-ft (21.5 MCM) per year. Therefore, due to 

additional infrastructure needed to reach more 

customers, the overall system cost has increased 

compared to original estimates. 

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Xcel Energy’s Cherokee Station

Authors: Abigail Holmquist, P.E. (Honeywell) and Damian Higham (Denver Water)

US-CO-Denver Energy

Project Background

Cherokee Station is one of Xcel Energy’s largest 

Colorado power plants in terms of power production 

capability, Figure 1. Cherokee Station is located just 

north of downtown Denver, and can produce 717 MW 

of power. Cherokee is a coal-fired, steam-electric 

generating station with four operating units. The fuel 

source for the plant is low-sulfur coal supplied by 

several mines in western Colorado. The plant is also 

capable of burning natural gas as fuel. Cherokee uses 

5,000 to 9,000 ac-ft/yr (393 MCM/yr) of water for 

cooling tower feed. Historically, all cooling tower water 

originated from nearby rivers that provided raw water 

to the plant.

Capacity and Type of Reuse 

Application 

The Denver Water Recycling Plant is located about a 

half mile away from Cherokee and can produce 30 

mgd (1310 L/s) of reclaimed water. As a conservation 

effort, Xcel Energy has taken steps to reduce fresh 

water consumption at the power plant. As part of this 

effort, Cherokee began using reclaimed water in 2004 

and is now the largest customer of reclaimed water 

from the Denver Water Recycling Plan, using up to 

5,200 ac-ft/yr (227 MCM/yr) of reclaimed water. 

Today, Cherokee utilizes multiple sources of water to 

provide a diverse, reliable and affordable source water 

portfolio. Raw water is the least expensive option, and 

is used as the primary source. Cherokee combines 

raw water with reclaimed water in a large reservoir 

before feeding the cooling towers. This blend of raw 

and reclaimed water is also used on site for ash silo 

wash down and fire protection. The recirculating water 

system for the cooling towers typically runs four to five 

cycles and uses bleach as a biocide. When the 

conductivity of the cooling water necessitates 

blowdown, the cooling tower wastewater is treated 

with lime and ferric chloride to meet permit 

requirements for metals and other constituents before 

it is discharged into the South Platte River.

Water Quality Standards and 

Treatment Technology 

The Denver Water Recycling Plant purifies secondary 

effluent using a biological aerated filter to nitrify high 

source water ammonia which can cause brass fittings, 

common in industrial plants, to become brittle over 

time. This process is followed by conventional drinking 

water treatment to remove high phosphorus and 

turbidity. Unit processes in this treatment train include 

coagulation, flocculation, sedimentation, filtration and 

disinfection.

The Colorado Department of Public Health and 

Environment regulates reclaimed water through 

Regulation 84, which sets forth treatment standards 

and allowable uses for different reuse categories. 

Category 3 water is produced by the plant and has a 

limit for E. coli that includes less than 25 percent 

Figure 1

Cherokee Station (Photo credit: Xcel Energy)

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detects in any month, with a maximum of 126 

cfu/100mL in a single sample. 

Turbidity must not exceed 5 NTU in more than 5 

percent of samples in a month and 3 NTU as a 

monthly average. Additional treatment targets for 

ammonia and phosphorous at the recycling plant were 

developed, in cooperation with Xcel Energy to ensure 

that reclaimed water quality would be suitable for 

cooling tower feed. Typical reclaimed water quality 

parameters are shown in Table 1. 

Table 1 Water quality parameters

Parameter Units Typical Range

Alkalinity, Total as CaCO3 mg/L 50-150

Ammonia as N mg/L 0-0.4

Boron mg/L 0.2-0.4

Calcium mg/L 40-70

Chloride mg/L 65-170

Chlorine, Total mg/L 1.5-4.0

Iron mg/L 0.05-0.6

Magnesium mg/L 5-20

Manganese mg/L 0.003-0.08

Nitrate + Nitrite as N mg/L 5-30

Nitrate as N mg/L 5-20

Nitrite as N mg/L 0.01-0.05

Ortho Phosphorous, 

Dissolved as P mg/L 0.04-0.3

pH SU 6-8 

Phosphorous, Total as P mg/L 0.04-0.4

Potassium mg/L 10-20

Sodium mg/L 90-200

Specific Conductance mg/L 360-1250

Sulfate mg/L 80-250

Temperature 0C 10-30

Total coliform MPN/ 

100mL <1.0

Total Kjeldahl Nitrogen mg/L 0.2-2 

Total Organic Carbon mg/L 4-8 

Project Funding

In order to receive reclaimed water service, Xcel 

Energy paid a system development charge (tap fee) to 

Denver Water and for construction of transmission 

facilities dedicated to their service. Costs were funded 

as capital improvements through Xcel Energy’s annual 

capital budget. Cherokee pays $1.05/1,000 gallons 

($0.28/m3

) of reclaimed water and a $5.58 monthly 

service charge. The rate increases to $1.11/1,000 

gallons ($0.29/m3

) in 2012.

Successes and Lessons Learned

Cherokee has not encountered any problems using 

reclaimed water in the cooling water system or other 

plant processes, including fire protection and ash silo 

washdown. The major benefit of reclaimed water to 

Cherokee is the availability of a new water source and 

an overall increase of water supply. This is very 

important in dry or drought years when raw water 

sources may be less readily available or water rights 

priorities come into play. 

There were factors that played larger roles than 

anticipated after initial program implementation. One 

was the effect that raw water pricing had on reclaimed 

water demand; a minimum use of reclaimed water was 

incorporated into the initial contract to provide the 

necessary demand to justify construction of the WRF. 

The expectation was that usage would grow with time; 

however, usage instead remained stagnant at the 

contract minimum due to the price of raw water making 

it the preferred water source. Another factor was 

accounting for possible changes in fuel sources when 

forecasting future reclaimed water demand. Natural 

gas power generation is less water-intensive than coal, 

reducing demand from on the plant; this was not 

anticipated in preliminary use projections. 

Other emerging factors included possible effects of 

peripheral ground water regulations on the legality of 

impoundments, which were thought to be covered only 

by reclaimed water regulations. Recently, however 

groundwater discharge permitting has been discussed 

which would have significant repercussions, such as 

lining an impoundment or obtaining a ground water 

discharge permit. Another emerging factor is the 

impact of reclaimed water quality on Cherokee 

meeting effluent limits of its industrial discharge permit; 

changes to discharge parameter limits may 

necessitate modification of the current treatment 

process to meet potentially more stringent discharge 

limits due to reclaimed water use.

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2012 Guidelines for Water Reuse

Effects of Recycled Water on Soil Chemistry

Authors: Abigail Holmquist, P.E. (Honeywell) and Damian Higham (Denver Water)

US-CO-Denver Soil

Project Background

In 2004, Denver Water began providing recycled water 

to customers in the greater Denver metro area. Nearly 

all of the original and current recycled water customers 

are landscape irrigators who had historically used 

potable water or raw water for irrigation. In an effort to 

provide information regarding effective recycled water 

use, Denver Water implemented a soil monitoring 

program designed to study soil characteristics of 

landscape irrigation sites before commencing irrigation 

with recycled water, and after 5 years of irrigation with 

recycled water. The results are provided as a resource 

for landscape managers irrigating with recycled water 

to help identify options for management strategies to 

ensure healthy landscapes.

Recycled Water Treatment and Quality 

The Denver Water Recycling Plant utilizes a biological 

aerated filter to nitrify high source water ammonia. The 

biological process is followed by conventional drinking 

water treatment to remove high phosphorus and 

turbidity. Unit processes in the treatment train include 

coagulation, flocculation, sedimentation, filtration and 

disinfection. The plant is capable of producing up to 30 

mgd (1300 L/s) and was constructed to allow build-out 

of 45 mgd (1970 L/s). The plant produces water, 

designated as “Category 3” as defined by the Colorado 

Department of Public Health and Environment 

(CDPHE), which must meet the following limits:

 E. coli - 126 cfu/100mL maximum and nondetect in at least 75 percent of samples

 Turbidity – 3 NTU or less as a monthly average 

and 5 NTU or less in 95 percent of samples.

While E. coli and turbidity are the only additional 

requirements CDPHE requires providers to meet 

through the recycled water regulations, nitrate is of 

concern whenever there is a potential discharge to 

surface or groundwater, making permitting necessary 

for most dewatering and unlined storage activities. 

Typical characteristics of recycled water are shown in 

Table 1. 

Table 1 Typical reclaimed water quality 

Water Quality Parameter Value 

Electrical Conductivity ECw (dS/m) 0.89

Total Dissolved Solids TDS (mg/L) 570

pH 6.92

Sodium Adsorption Ratio, adjusted (SARadj) 3.7

Sodium - Na (mg/L) 130

Chloride - Cl (mg/L) 99.3

Boron - B (mg/L) 0.28

Bicarbonate - HCO3 (mg/L) 66

Nitrate - NO3-N (mg/L) 14.1

The nitrogen in Denver Water’s recycled water allows 

irrigators, who make up 35 percent of the demand on 

the system, to cut back significantly on fertilization. 

This water also has higher concentrations of salts, 

primarily sodium and chloride, than potable water, and 

thus requires different management approaches to 

ensure soil and plant health. 

Soil Sampling and Testing 

In the fall of 2004, samples were taken from 10 sites 

including golf courses, parks and school grounds. At 

least three soil borings were collected from each site 

up to 40 in (100 cm) in depth. The cores were split into 

sub-samples representing 8-in (20-cm) strata and 

composited for each stratum at each sample site. The 

sampling protocol was repeated in the fall of 2009 at 

the same sites with samples being collected one foot 

from previous locations. Soil compaction and irrigation 

uniformity were also evaluated during both sampling 

events. 

Testing was performed at the Colorado State 

University Soil, Water & Plant Testing Laboratory. Soil 

samples were evaluated for texture and dried, ground 

and screened prior to further testing. Boron, calcium, 

cation exchange capacity (CEC), chloride, copper, 

electrical conductivity, exchangeable sodium, iron, 

magnesium, manganese, nitrate, organic matter, pH,

phosphorous, potassium, sodium and zinc were 

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measured using standard methods. These results 

were used to calculate sodium absorption ratio (SAR), 

salinity and exchangeable sodium percentage (ESP).

Results 

Results suggested that sodium and sodium-related 

parameters are of the greatest concern for soil health, 

with average ESP and SAR values approximately 

doubling over the five-year period. 

Nitrate concentrations in soil irrigated with potable and 

recycled water was studied in 2009 as a function of 

soil depth (Figure 1). Nitrate content decreased 

significantly with soil depth, indicating that nitrate 

contamination of groundwater should not be of great 

concern when using recycled water for the irrigation of 

turf systems. This data demonstrates that dense, wellmanaged, and active-growing turf grasses serve as 

bio-filtration systems for removal of excess nitrate.

While reclaimed water quality affects landscapes, 

other factors, such as soil compaction, irrigation 

uniformity and precipitation can affect how water 

quality impacts landscape health and how that health 

is quantified. For example penetrometer readings of 

greater than 300 psi (2,070 kPa) indicate potential 

problems for plant growth due to soil compaction and 

this reading was exceeded in at least one subsample 

location, at four of ten study sites.

Irrigation uniformity (IU) is the measure of the 

consistency of water application. A poor IU can result 

in one area of landscape receiving too much water and 

another area receiving too little. All sites, except two, 

had a good to excellent irrigation uniformity. No clear 

relationship between irrigation distribution uniformity 

and measured soil parameters was observed. 

Lessons Learned: Management 

Options for Recycled Water Providers 

Recycled water can be a good source of irrigation 

water, depending on its quality, the type of soil, type of 

plants and the management practices employed. 

Denver Water’s recycled water is well-suited for most 

landscapes in the surrounding area. Some tree 

species and soil types, however, can be sensitive to 

elevated sodium and other constituents and may 

require proper management to avoid damaging 

effects.

Because conditions vary by location, each recycled 

water provider must evaluate its system and the needs 

of potential customers to identify the most appropriate 

recycled water management strategy. Wherever 

recycled water is used for irrigation, regular monitoring 

of water and soil quality is recommended. Based on 

this research and the findings of others, the following 

best management practices can help to mitigate 

potential negative effects of irrigating with recycled 

water:

 Flushing: While consistent over-irrigation is not 

recommended, periodic over-watering or 

flushing may facilitate the movement of salts out 

of the root zone. This may also occur with heavy 

rainfall.

 Aeration: Aeration is the practice of removing 

small plugs of soil from the root zone and 

randomly discarding them on the turf surface. 

Aeration improves the movement of water 

through the soil, reduces soil compaction, and 

decreases thatch buildup thus minimizing 

potential for ponding and salt buildup in the root 

zone.

 Rotor head replacement: Using low-trajectory 

heads to avoid excessive spray on tree foliage 

can reduce harmful effects.

 Sodium replacement amendments: Gypsum 

(CaSO4), calcium chloride (CaCl2), or utilization 

of “sulfur burners” or sodium blockers have 

shown promise in limiting effects of sodium by 

displacing sodium bound to soil, thereby helping 

to leach sodium to deeper depths.

 Humates: Humates and humic acid are organic 

materials derived from decaying plant material. 

These substances are claimed to buffer salts, 

Figure 1

Soil nitrate profile

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augment micronutrient availability to plants, 

promote soil aeration and water penetration, 

and encourage flocculation of soil particles.

 Vesicular-arbuscular mycorrhizal (VAM) 

inoculation: In some studies, recycled water

irrigation has been found to deplete arbuscular 

mycorrhizae, which help plants to capture 

nutrients from the soil, though the mechanism 

for the depletion is unclear. This affect may be a 

significant constraint on landscape plant 

performance under saline conditions. 

Innoculation with VAM has been shown to be 

beneficial in some studies, especially when 

mycorrhizae are not well-establish in the soil.

 In cases where the potential for cross 

connections can be minimized or eliminated, 

blending recycled water with potable or raw 

water for irrigation or rotating between different 

water sources can help minimize sodicity 

issues.

 More intensive cultivation programs (deep 

aeration and water injection) to maintain oxygen 

diffusion and water movement, improved 

drainage systems and more vigorous traffic 

control programs, to avoid overuse of turf areas, 

can help alleviate compaction problems and 

promote drainage.

 Recycled water can provide nutrients, 

potentially fully or partially offsetting the need for 

chemical fertilizer. To avoid nutrient imbalances, 

analyses should be conducted to account for 

the nitrogen and phosphorous fertilizer value 

present in recycled water compared to soil 

nutrient content and crop requirements. 

Maintaining healthy plants that can withstand 

environmental stresses better and replacing 

susceptible plants with adapted, salt tolerant 

species and cultivars will alleviate most 

problems that cannot be solved with other 

corrective measures presented in this study.

As reuse becomes more prevalent, additional 

information will be collected to ensure proper use of 

this valuable resource. Denver Water will continue to 

monitor both new and existing sites to build an 

understanding of how sites evolve with recycled water 

use in the future.

Institutional and Cultural 

Considerations 

Introducing recycled water as a source of irrigation 

water supply has necessitated significant outreach to 

the public, in general, and especially in areas supplied 

with recycled water. The source of recycled water and 

relative infancy of regulatory programs led to 

apprehension on the part of irrigators and the public as 

to health effects of recycled water use for the 

landscapes irrigated and the public enjoying them.

Panel discussions including industry experts, irrigators 

and the public were held at the start of this process to 

gauge concerns and how best to address them. 

Denver Water attended events parks and schools 

using recycled water to provide an opportunity to 

inform and address questions and concerns of local 

residents. Users were afforded the opportunity to 

attend forum discussions to voice concerns and find 

solutions to problems arising from recycled water use. 

Users were also required to attend an informational 

training session triennially to inform personnel about 

hazards associated with handling recycled water use 

and how to mitigate those hazards.

Some concerns surrounding recycled water use 

emerged within Denver Water as well. The cost of 

treating recycled water was higher than that of potable 

water and a holistic approach involving costs of new 

sources of supply and drought preparedness needed 

to be conveyed effectively in order to overcome those 

internal concerns. Additionally, supplanting potable 

use with recycled use shifted demands and led to 

some potable systems already in place becoming 

over-sized resulting in additional management and 

operational considerations. 

References

Yaling Qian, 2009. Soil Testing Five Years after 

Irrigation with Recycled Water. 

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2012 Guidelines for Water Reuse

Sand Creek Reuse Facility Reuse Master Plan

Authors: Bobby Anastasov, MBA and Richard Leger, CWP (City of Aurora)

US-CO-Sand Creek

Project Background

The city of Aurora, Colo., developed a Reuse Water 

System Master Plan Update with short-range and 

long-range plans to improve and expand its reuse 

water system. A previous study (2003) explored 

options for maximizing reuse by building a large 

reclaimed water reservoir in the eastern plains or 

constructing new treatment facilities. The goal of this 

update was to explore other options for optimization of 

the reuse system, including expansion of the Sand 

Creek Water Reuse Facility (WRF), addition of 

operational storage system, and eventual inclusion of 

annual storage for reuse water. The study included the 

following:

1. Evaluation of sources and availability of reclaimed 

water

2. Evaluation of existing and future demands

3. Evaluation of potential reuse storage sites for 

local, operational and annual storage

4. Development of a hydraulic model of the existing 

reuse water system and scenarios for phased 

expansion of the system

5. Development of a capital improvements plan (CIP) 

for the Sand Creek WRF service area

6. Evaluation of Prairie Waters as a potential raw 

water irrigation source

7. Cost evaluation of reuse water produced at the 

Sand Creek WRF versus raw water from the 

Prairie Waters, a drinking water project utilizing 

Aurora’s water rights to extract water through 

riverbank filtration along the South Platte River for 

drinking water supply

Two water sources were identified for non-potable 

irrigation sources: reuse water from the Sand Creek 

WRF and raw water from the Prairie Waters (PW) 

pipeline. The Sand Creek WRF is capable of providing 

5.0 mgd (219 L/s) as currently operated, with potential 

to expand to 6.5 or 7.3 mgd (285 or 320 L/s). Raw 

water from PW will be available at an initial capacity of 

12 mgd (526 L/s) in 2011, with an ultimate capacity of 

50 mgd (2190 L/s). 

A comprehensive list of demands was developed as 

part of the study including: parks, golf courses, 

schools, greenbelts, medians, cemeteries, residential 

developments, office parks and industrial users. More 

than 200 separate demand locations were identified 

throughout Aurora. Generally, demands within the 

existing system and surrounding the Tollgate Creek 

corridor were considered to be served from the Sand 

Creek WRF. Demands east of E-470 and north of I-70 

were to be served from the PW pipeline. Demands 

located within the Cherry Creek Basin will not be 

served by either source due to nutrient loading 

(phosphorus) restrictions.

Capacity and Type of Reuse 

Application 

Existing customers are provided reuse water from the 

Sand Creek WRF. The facility uses a biological 

nutrient removal (BNR) activated sludge process 

followed by tertiary filtration and UV disinfection to 

produce 5 mgd (219 L/s) of reclaimed water. In-plant 

waste flow generated at the facility is returned to the 

Metro Wastewater Reclamation District’s (MWRD) 

interceptors for further treatment at the MWRD’s 

Central Plant. Reuse water is pumped from the Sand 

Creek WRF into the reuse water system. 

Currently, the Sand Creek WRF only utilizes 

approximately 26 percent of its available annual 

volume for distribution to reuse customers, largely due 

to a lack of storage within the system, requiring the 

Sand Creek WRF to provide each demand location 

with peak day flows. Addition of operational or annual 

storage within the system would allow for a greater 

percentage of total annual volume to be reused. More 

than 30 storage sites were evaluated ranging from 0.3 

to 1,140 million gallons (1135 m3 to 4.3 MCM) of reuse 

water storage. Storage sites are located throughout 

the city and many of the sites for operational storage 

are located within the limits of the existing reuse water 

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system. Sites for annual storage are generally located 

at the eastern boundary of the city.

One of the primary goals of the study was to optimize 

the reuse water system by making use of the portion of 

reuse volume from the Sand Creek WRF that is 

currently being discharged to Sand Creek. A plan for 

optimizing the system was developed which uses a 

combination of pipeline, pump station and storage 

facility improvements to increase the irrigated acreage 

of the reuse water system. A schedule of major 

recommended improvements has been incorporated 

into a capital improvements plan (CIP) to provide a 

framework for design, construction, operation and 

financing of the improvements required to optimize the 

reuse water system (Table 1). Each phase is a step 

toward the ultimate goal of extending reuse water 

down the Tollgate Creek corridor to provide reuse 

water to the central and southern portions of Aurora. 

Project Funding and Management 

Practices 

The CIP outlining expansion of the reuse water system 

through 2025 phases improvements to limit rates to 

approximately 75 percent of anticipated commercial 

potable water rates and 66 percent of anticipated 

potable irrigation rates. 

The costs of using treated water from the Sand Creek 

WRF versus using raw water from the PW system 

were compared for the existing and future irrigation 

water demands of the city’s reuse system. The 

following costs were included in the comparison:

 Water loss in the South Platte River (7 percent)

 Capital improvements for the Sand Creek WRF 

and PW connection

 Sand Creek WRF operation and maintenance 

(O&M) costs

 MWRD O&M costs for additional wastewater 

treatment with the Sand Creek WRF offline

 Transmission and distribution (T&D) O&M costs 

and T&D capital improvements

 Debt service for the Sand Creek WRF

 Debt service for the existing T&D system and 

PW T&D

Successes and Lessons Learned

Without a master plan the city of Aurora would have no 

comprehensive document guiding its long term vision 

of the reuse water system. The plans should be 

revisited on a regularly to ensure they still reflect the 

vision of the city. 

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Table 1 Summary of recommended improvements

Phase 

and Year Pipeline Improvements

Pumping 

Improvements Storage Improvements

Additional 

Irrigated 

Acres

Total 

Construction

Cost1,2

Phase 1

2010

 Coal Creek Area/Rio 

Grande Pit Connection 

Sand Creek Park 

Connection

 Signature Park 

Connection

SCWRF Pump 

Station Expansion 

(6.5 mgd) 

 Aurora Hills GC Pond 

Expansion (1.2 MG)

 Rio Grande GC Pond 

Expansion (2.0 MG)

 Sand Creek Park Pond 

(0.4MG) 

 Signature Park Pond (2.7MG)

 Spring Hill GC Pond 

Expansion (1.1MG) 

197 $11.4 M

Phase 2

2015

n/a n/a

 Fitzsimons GC Pond 

Expansion (1.6 MG)

 Murphy Creek GC Pond 

Expansion (1.4 MG) 

 Sand Creek pond Expansion 

(2.0 MG) 

 SCWRF Operational Storage 

(2.0 MG)

306 $16.1 M

Phase 3

2020

 Delaney Farm Pump 

Station 

 Main Iliff Pump Station 

 Main Iliff Service Main

 Wheel Park Connection

 Delaney Farm 

Pump Station 

(6.5 mgd)

 Iliff Pump Station 

(2.2 mgd)

 Delaney Farms Operational 

Storage (5.0 MG)

 Wheel Park Pond (2.5 MG)

364 $39.5 M

Phase 4A

2025

 Heather Gardens GC 

Connection

 Heather Ridge GC 

Connection

n/a

 Heather Gardens GC Pond 

(1.6 MG)

 Heather Ridge GC Pond 

(4.1MG)

486 $82.8 M

Phase 4B

2025

 Aurora Dog Park 

Connection

 Aurora Hills 

Interconnect 

 Buckley Air Force Base 

Connection 

 Expo Park Connection 

 Quincy Reservoir Main 

Rocky Ridge Park 

Connection 

 Summer Valley Park 

Connection

n/a

 Aurora Dog Park Pond 

(3.7 MG)

 Buckley Air Force Base Pond 

(4.3 MG)

 Expo Park Pond (6.4 MG)

 Heather Ridge GC Pond 

Expansion (0.7 MG)

 Quincy Reservoir (380 MG)

 Rocky Ridge Park Pond 

(2.3 MG)

 Summer Valley Park Pond 

(4.7 MG)

 Wheel Park Pond Expansion 

(2.1 MG)

1416 $97.6 M

1 Construction costs are in 2008 dollars

2 Construction costs for each phase include costs for previous phases

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2012 Guidelines for Water Reuse

Water Reuse Barriers in Colorado

Author: Cody Charnas (CDM Smith)

US-CO-Water Rights

Background of Colorado Water Law 

Due to water laws in Colorado, water reuse has many 

barriers that limit its implementation. Due to the limited 

amount of precipitation in Colorado, it is a precious 

resource that is essential for its residents. All the rain 

and moisture that falls within the state of Colorado is 

property of the state. The allocation of water is 

governed by “prior appropriation,” which is also 

commonly referred to as “first in time, first in right.” 

Residents of Colorado can use the water for beneficial 

use if they own the water rights. This process of 

obtaining a water right is known as adjudication. With 

a water right, a resident owns the right to use the 

water, but they don’t own the water. In addition, water 

that is not consumed for beneficial use must be 

returned to the river or stream by surface run-off or 

through subsurface infiltration. These returned flows 

are used by junior appropriators downstream. 

As the population continues to increase in Colorado, 

the demand for water is also increasing. Other states 

with limited water supplies, such as Arizona and 

California, reuse water to supplement the limited 

resource. As a result of water laws in Colorado, water 

reuse and use of alternative water supplies is often not 

allowed. For example, rainwater harvesting and 

graywater use are prohibited.

Reuse in Colorado 

In general, Colorado water law allows for one use of 

the water by the original appropriator. However, any 

water that is brought in to a watershed that is not 

connected to its original source is considered foreign 

water. Water that is considered foreign can be reused 

by its owner as it will never enter back into its source 

watershed. For example, water that is diverted from 

the West Slope to the east side of the Continental 

Divide is considered foreign as it will never flow back 

to the west side of the Continental Divide. Waters that 

are also considered foreign include nontributary 

groundwater introduced into a surface stream as well 

as water imported from an unconnected stream 

system (“transmountain water”). 

Once the importer brings foreign water from an 

unconnected source the owner can reuse the water to 

extinction as it is considered “fully consumable.” 

However, the owner must maintain dominion and 

control over the water. “Dominion and control in this 

context refers to the intent to recapture or reuse such

water, and is not lost when a municipal provider 

delivers water to a customer’s tap or when consumers 

use such water to irrigate lawns” (CWCB, 2010). 

In addition to being able to reuse water classified as 

foreign, agricultural water rights that are transferred to 

municipal use are considered fully consumable and 

can be used to extinction. The reason for this is 

“because the applicant in a change of use proceeding 

may take credit for, and reuse, the historical 

consumptive use (CU) associated with the prior

decreed use” (CWCB, 2010). The water attributable to 

the historical CU of the senior water right may be 

reused to extinction. 

Two larger utilities in Colorado that are currently 

reusing water include Denver Water and Colorado 

Springs Utilities. The reclaimed water is used for 

irrigating parks, golf courses and schools, cooling at 

power generating plants, and the Denver Zoo. 

References

Colorado Foundation for Water Education. 2004. 

Citizen’s Guide to Colorado Water Law. 2nd Edition.

Colorado Water Conservation Board (CWCB). 2010. 

Statewide Water Supply Initiative 2010. 

Trout, R.V., Witwer, J.S., and Freeman, D.L. 2004. 

Acquiring, Using, and Protecting Water in Colorado.

Denver, CO: Bradford Pub.

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2012 Guidelines for Water Reuse

Smart Water Management 

at Sidwell Friends School

Authors: Laura Hansplant, RLA, ASLA, LEED AP (Andropogon Associates [formerly]

and Roofmeadow) and Danielle Pieranunzi, LEED AP BD+C (Sustainable Sites Initiative)

US-DC-Sidwell Friends

Project Background or Rationale 

Sidwell Friends School (SFS) in Washington, DC, 

incorporated a constructed wetland into its Middle 

School building renovation. This water reuse system is 

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 utilizes storm 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 and there 

was extensive use of reclaimed stone for steps and 

walls. Concrete containing recycled slag is used for 

walkways and reclaimed wood was used for the 

decking surfaces. Completed in 2007, the Middle 

School project was the first K-12 school to achieve a 

Leadership in Energy and Environmental Design 

(LEED) Platinum rating from the U.S. Green Building 

Council. 

Capacity and Type of Reuse 

Application 

The SFS facilities sit on a 15-acre campus in 

northwest Washington, D.C. The environmentally 

responsible stormwater and wastewater management 

systems are prominent in the landscape in order to 

promote education and to build awareness. The 

centerpiece of the new Middle School is a natural 

wastewater treatment and reuse system that produces 

high-quality water suitable for non-potable uses. A 

constructed wetland forms the heart of this system. It 

uses biological processes to clean water and serves 

as a living laboratory where students can learn about 

biology, ecology, and chemistry (Figures 1 and 2). 

Figure 1

Natural wastewater treatment and reuse system (Image: Courtesy of Andropogon Associates)

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Wastewater is processed through the courtyard 

systems for approximately 3 to 5 days before entering 

a storage tank in the basement. From there it passes 

through 10 and 100 micron filters and is UV disinfected 

before being fed back into toilets and urinals in the 

building through a parallel set of pipes designated for 

recycled water. The project cost approximately 

$4 million (for site-related work) and was funded by the 

school.

Water Quality and Treatment 

Technology 

Wastewater from the Middle School building is 

processed in a multi-step system that incorporates a 

variety of ecologies to provide robust, diverse 

treatment. System components include a passive 

primary treatment tank, followed by a series of 

terraced subsurface-flow constructed wetland cells, a 

recirculating sand filter, and trickling filter, which are all 

tightly integrated into the courtyard's landscape. The 

choice of subsurface-flow, as opposed to surface-flow, 

reduces or eliminates odor and prevents contact with 

the water. A variety of native and local wetlands plants 

provide an aesthetically pleasing landscape while their 

roots host a wide diversity of microorganisms that help 

break down contaminants from the water. The trickling 

filter and sand filter provide further polishing and 

reduction of nutrients such as nitrogen. 

SFS engaged Lucid Design Group to monitor water 

quality within the constructed wetland system, and to 

display the data on a website for classroom use. The 

District of Columbia requires both regular water quality 

monitoring of the waste water system and periodic 

groundwater monitoring, to confirm that the system is 

functioning as planned. 

The Middle School's stormwater system is a 

combination of vegetated roofs, swales, rain gardens, 

and a pond that double as outdoor classroom space. 

All the building roof runoff is conveyed to the pond via 

downspouts and an aqueduct along the access ramp 

that provides handicap access to the building. During 

large storm events, the pond overflows into the rain 

garden for biofiltration and infiltration, mimicking the 

functions of a natural floodplain. The rain garden is 

planted with native wet meadow species. The 

vegetated roof provides habitat for pollinators and also 

reduces runoff volumes. To address improving runoff 

water quality, the overland flow of runoff from paved 

areas is routed through a storm filter to remove 

suspended solids and excess nutrients. Excess water 

from the lawn also flows to the courtyard's pond. Some 

of the roof runoff is stored in an underground cistern, 

which provides additional water for the pond during dry 

weather. No permanent irrigation system was installed. 

None of the stormwater is combined with treated 

wastewater for non-potable use in buildings.

Institutional/Cultural Considerations 

The water reuse installation is used in the school 

curriculum (Figure 3). SFS students monitor the 

building functions and constantly measure the "health" 

of the facility. Teachers of every grade level have 

access to the building's exposed systems for the study 

of flora and fauna, rainforests, human cellular 

structure, and environmental science, as well as many 

aspects of the mechanical, electrical, structural, and 

plumbing systems. For their Environmental Science 

class, 8th Grade students participate in labs in which 

they measure and compare nitrogen and phosphorus 

levels in various levels of the wetland and in the 

basement reuse holding tank, and learn the valuable 

role that wetlands play in purifying water. The 

Advanced Placement Environmental Science students 

conduct labs including comparing water quality in the 

on-campus biology pond to water in a nearby tributary, 

studying the invertebrate biodiversity in the soil on the 

green roof, and comparing stormwater runoff from the 

green roof with runoff from the conventional roof. 

Students and others at SFS are also encouraged to 

record wildlife sightings such as a Snowy Owl or 

Monarch Butterflies through the school's website. The 

biodiversity in the woods, wetlands, and native 

Figure 2

View of new building extension (Photo: Courtesy of 

Andropogon Associates)

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vegetation provide real-life lessons for the science 

classes. On the green roof, students also learn how to 

grow vegetables and herbs that are used in the 

school's cafeteria.

The Center for Sustainable Environmental Design, a 

collaborative effort between the Yale School of 

Forestry and Environmental Studies and the Yale 

School of Architecture, is conducting research to 

connect environmental science and management with 

architectural design and engineering. At SFS, a 

research team is studying the school to determine if 

the project's green strategies have a measurable 

effect on student and faculty performance and health. 

While the school was still using the older building, 

extensive questionnaires were administered to 

students, teachers, and staff. Numerous questions 

probed their awareness of the building, satisfaction, 

and environmental sensitivity. The response to these 

questionnaires will act as the baseline for the study. 

Additional surveys will continue to be conducted. This 

data will provide the first analytical examination of the 

effect of biophilic design on occupant satisfaction and 

performance.

Successes and Lessons Learned

When site systems become highly integrated, they 

achieve both efficiency and interdependence. For 

example, the green roof provides efficiency for both 

the stormwater system and the building HVAC 

systems; this efficiency also means that the 

stormwater system and the HVAC system also 

became dependent on the green roof for their efficient 

sizing. Consequently in integrated designs of this type, 

changes to project scope, whether for budgetary or 

philosophical reasons, need to be considered 

holistically. Projects of this complex nature are difficult 

to implement with a standard project delivery system. 

A very close partnership between the design team, the 

client, and the construction team is needed in order to 

help the contractors effectively organize and build 

these new, sustainable, site systems.

Figure 3

View of rain garden and pond (Photo: Courtesy of 

Andropogon Associates)

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2012 Guidelines for Water Reuse

South District Water Reclamation Plant

Authors: R. Bruce Chalmers, P.E. (CDM Smith) and 

James Ferguson (Miami Dade Water and Sewer Department) 

US-FL-Miami So District Plant

Project Background or Rationale 

The Miami Dade Water and Sewer Department 

(MDWASD) is the largest water and sewer utility in 

Florida, serving more than 2.2 million residents. It has 

three major water treatment plants, providing 

approximately 90 percent of the county’s public water 

supply. Rapid population growth, drought, and 

environmental efforts to restore the Everglades 

created pressure for increased groundwater extraction 

to meet the additional demands. At the same time, the 

South Florida Water Management District (SFWMD) 

prohibited additional withdrawals from the Biscayne 

aquifer, which required MDWASD to develop new 

alternative water sources. 

MDWASD agreed to implement a series of projects to 

meet the increasing demand, including aquifer storage 

and recovery (ASR), Floridan aquifer blending, 

Floridan aquifer brackish water treatment, and the 

South District Water Reclamation Plant (SDWRP) for 

indirect potable reuse. The SDWRP will help the 

county meet future water demands while protecting 

environmental resources.

Capacity and Type of Reuse 

Application 

SDWRP will treat South District Wastewater Treatment 

Plant (SDWWTP) tertiary effluent to potable water 

quality. The capacity of the SDWRP will be 21 mgd

(920 L/s) of advanced water treatment. Product water 

from the SDWRP will be recharged approximately 

6 miles (9.6 km) away, at the Miami-Dade Metro Zoo. 

Recharged water will be injected into the Biscayne 

aquifer, the county's main drinking water source, 

upgradient of a county water supply wellfield. There 

will be seven groundwater injection wells with a total 

hydraulic mound of less than 1 foot. The recharged 

water will offset an average annual flow of 18.6 mgd 

(815 L/s) at the new South Miami Heights potable 

water treatment plant (SMHWTP). The SDWRP 

project facilities are shown in Figure 1. The SDWRP is 

required to be online by the end of 2014.

Figure 1

SDWRP facilities (Photo credit: CDM Smith 2008)

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Water Quality Standards and 

Treatment Technology 

The Florida Department of Environmental Protection is 

the state agency that has jurisdiction over 

implementation of reclamation treatment plants, 

specifically Part V of the Florida Administrative Code, 

Section 62-610 that regulates the detailed 

requirements applicable for the SDWRP. Part V also 

regulates applications for recharge facilities, including 

injection wells. Significant SDWRP water quality 

requirements are shown in Table 1. 

Table 1 SDWRP water quality requirements

Parameter

FDEP 

Part V

(mg/L)

DERM WQ 

Standards

(mg/L)

DERM 

CTLs

(mg/L)

TOC 3 N.R. N.R.

TDS 500 500

Total Nitrogen 10 N.R. N.R.

Ammonia N.R. 0.5 2.8

Phosphorus 

(μg/L) N.R. N.R. (< 10 proposed) N.R.

NDMA (ng/L) N.R. N.R. <2 

A local county agency, the Department of Environment 

Resources Management (DERM) also has water 

quality standards (WQSs) that govern discharges and 

groundwater clean-up target levels, which are 

implemented for groundwater clean-up activities. 

Using the county’s non-degradation policy, DERM also 

required very low effluent concentrations for 

phosphorus, NDMA, and other limits not specifically 

included in the WQSs. DERM requirements are also 

shown in Table 1. 

Figure 2 shows the SDWRP process flow diagram. 

The SDWRP will have technologies successfully 

proven at Orange County Water District’s (OCWD) 

Groundwater Replenishment System in Fountain 

Valley, California, including membrane filtration (MF), 

reverse osmosis (RO), and ultraviolet light with 

hydrogen peroxide (UV-AOP). Ion exchange will be 

added after the RO to meet the required ammonia 

limit. Major design criteria are shown in Table 2. MF 

backwash will be returned to the SDWWTP for 

treatment. RO brine will be discharged to a deep well 

for disposal.

Figure 2

SDWRP process flow diagram (Photo credit: CDM Smith/Hazen and Sawyer 2008)

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Table 2 Major system design information

System Number

of Trains

Train 

Capacity

(mgd)

Comments

MF 13+1 1.9 (1.76) 94% Recovery

RO 4+1 5.25 3-stage, 12 gfd

85% Recovery

IX 12+2 1.75 (1.5) Regeneration

UV-AOP 4+1 5.25 (4.2) 97% UVT 

Project Funding and Management 

Practices 

The SDWRP will have a total project cost of $357 

million and will be funded by Miami Dade County 

bonds. The estimated cost for each of the construction 

contract is provided in Table 3. 

Table 3 Estimate of probable construction costs

Phase Contract Cost

A MF Offer $13,400,000

B UV Offer $4,100,000

C Site Preparation/ Earthwork $18,800,000

D Off-site Pipelines $23,000,000

E SDWRP $195,100,000

F SDWWTP Deep Injection 

Well $1,700,000

Institutional and Cultural 

Considerations 

The benefits of the SDWRP include implementation of 

a new, reliable, sustainable source of water; local 

control; support from the regulators, and reuses water 

previously discharged to deep injection wells and 

wasted. 

The MDWASD’s Public Affairs staff has developed an 

initial, conceptual, strategic communication plan for the 

SDWRP that identifies some broad goals for a public 

outreach program under the outreach efforts 

conducted as part of the 20-year Water Use Permit 

campaign. 

Lessons Learned and Project Status 

Because of the recession, substantial reductions in 

demand, financing/costs, and changes in the 

regulatory environment, MDWASD is rethinking its 

commitment to completing the SDWRP project at this 

time. An alternative project, extracting water from the 

brackish Floridan aquifer, thereby eliminating the need 

to construct the SDWRP, reduces project costs 

substantially, making it a more favorable option. Lower 

growth rates also reduced the increases in water 

demands, allowing a delay in implementation to further 

evaluate alternatives.

Therefore, MDWASD has suspended the design of the 

SDWRP at the 90 percent design completion point. If 

the regulatory commitments to Floridan injection and 

reuse are not obtained, the project may be restarted 

with a new completion date.

References

Chalmers, R., J. Ferguson, and L. Llewelyn. South Florida’s 

Blueprint for Implementing an Advanced Recycled Water 

Treatment Facility, AWWA Annual Conference and 

Exposition, Washington D.C., June 12-16, 2011, AWWA, 

Denver, CO. 

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2012 Guidelines for Water Reuse

City of Pompano Beach OASIS

Authors: A. Randolph Brown and Maria Loucraft (City of Pompano Beach)

US-FL-Pompano Beach

Project Background or Rationale 

The city of Pompano Beach, Fla., began providing 

reuse for irrigation in 1989. Reuse began when the 

city’s golf course over-pumped its groundwater wells 

and was unable to obtain further withdrawals upon 

renewal of the consumptive use permit. When the city 

Utilities Department attempted renewal of the 

consumptive use permit for the city’s drinking water 

supply, the South Florida Water Management District 

(SFWMD) included reuse water as a permit 

requirement. The SFWMD also required an alternative 

water supply to address saltwater intrusion issues.

This was a challenge for the city, as it owned a sewer 

collection system, but no wastewater treatment facility

(treatment is provided by the Broward North Regional 

Wastewater Facility), and could not reclaim its own 

wastewater. Fortunately, the Broward North Regional 

Wastewater Facility had an ocean outfall line running 

through Pompano Beach to the ocean. The city built 

the reuse plant adjacent to the 54-in (137-cm) line to 

divert secondary effluent for further treatment (filtration 

and disinfection) to improve its quality for use in 

irrigating the golf course, medians, and parks within 

the city. This reuse practice has reduced groundwater 

withdrawals and increased recharge, which has 

contributed to the reversal eastward of the saltwater 

intrusion line in this area. Over 20 years later, the city 

also provides reuse water to another city (Lighthouse 

Point) and to residential customers. The city’s reuse 

pioneers gave the city a tremendous gift—the ability to 

sustain its water resources and better tolerate 

droughts. 

Several drivers have made increasing reuse the most 

promising means of sustaining water resources and 

quality of life in the city. Recent legislation limits 

withdrawals from the region’s groundwater aquifer 

(Biscayne Aquifer), requires closure of six ocean 

outfall lines in Eastern Florida by 2025 except during 

high volume stormwater periods, and requires a 

60 percent of the previously discharged secondary 

effluent to be used for beneficial reuse. For the North 

Broward County ocean outfall, this amounts to 22 mgd 

(964 L/s) for inland reuse. Conservation requirements 

for consumptive use permits, high population growth, 

and severe droughts with minimal stormwater storage 

capacity have likewise put pressure on the city to 

increase reuse. 

The city’s OASIS (Our Alternative Supply Irrigation 

System) program takes a systematic approach to 

increase reuse and further increase 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. 

With expansion possible up to 12.5 mgd (548 L/s), it is 

possible that OASIS could become a prime regional 

reuse provider.

The city’s greatest reuse challenge has been in 

convincing single family residential customers to 

connect to the system. While connection is mandatory 

for commercial and multi-family customers, the city did 

not mandate connection for single family residences. 

Approximately 1,200 homes to date are connected to 

the reuse system with only 73 single family 

connections. Even though construction of reuse mains 

required work in neighborhoods that placed a reuse 

meter box at each home, single family residential 

customers chose not to connect to the system. 

Reasons ranged from the cost of connection 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 Commission 

approved development of a connection program to 

target connection of single family residential 

customers. The new program allows the city, working 

through a contractor, to perform the necessary 

plumbing to connect the customer 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 a slightly higher reuse usage rate 

($0.85/1,000 gallons [$0.22/m3

] for the smallest meter 

size) than existing reuse usage rates ($0.61/1,000 

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gallons [$0.16/m3]). The program includes a public 

outreach campaign, “I Can Water,” which launched in 

July 2011 with meetings, media outreach, mailers, 

cable TV, webpage, and a hotline. To reward the 

existing 73 customers, the city will replace their 

backflow devices and keep them at the current lower 

rate. Customer response has been high.

Capacity and Type of Reuse 

Application 

In 1989, the original plant was constructed with a 

2 million gallon (7570 m3

) ground storage tank and a 

2.5 mgd (110 L/s) design flow. The plant was 

expanded to 7.5 mgd (330 L/s) in 2002, with the ability 

to expand up to 12.5 mgd (550 L/s). The city produces 

reclaimed water for parks, golf courses, playing fields, 

medians, and residential irrigation. Current usage is 

about 1.8 mgd (80 L/s).

Water Quality Standards and 

Treatment Technology 

Broward County effluent, which is the OASIS influent, 

is required to meet the state’s CBOD standard as part 

of its NPDES permit. The reuse facility consists of: two 

filter structures; associated pumps; a chlorine contact 

basin; two reuse water ground storage tanks (6 million 

gallon [22,710 m3

] capacity); two dedicated distribution 

systems (a high pressure system for the golf course 

and a low pressure system for irrigation of parks, 

medians, and residential customers); and a control 

system (run on Supervisory Control and Data 

Acquisition Systems [SCADA]) with telemetry to the 

water treatment plant for monitoring and control 

functions. Water quality requirements include:

 Fecal coliforms - 75 percent of samples must be 

non-detect with no single sample exceeding 

25 cfu/100mL

 Total suspended solids less than 5.0 mg/L 

 Chlorine residual greater than 1.0 mg/L

Project Funding and Management 

Practices 

The city finances the reuse program through user fees, 

an availability fee, and a use rate based on meter size. 

The potable water rate subsidizes 47 percent of the 

reuse program, spreading the costs to all customers. 

OASIS is required by the city’s potable water 

consumptive use permit and helps to defer additional 

capital improvements for potable water as well as 

defer other alternative water supply investments. The 

city issued a bond for construction of the treatment 

facility and main trunk line. The city has continued to 

aggressively seek grants for distribution system 

expansion, as well as feasibility/research projects. 

Broward County is providing a cost share grant up to 

$220,000 for the new “I Can Water” campaign. Since 

2004, the city has received $1.4 million in grants to 

further the reuse program.

Institutional and Cultural 

Considerations 

Broward County has stricter water quality standards 

than the State of Florida, which limits reclaimed water 

use in ways that are acceptable in other parts of the 

state or country. Local rules do not allow reclaimed 

water to be stored in unlined ponds, requiring lining 

storage ponds or using closed distribution systems to 

reach all end users. Local water quality standards also 

impede permitting of reuse recharge systems, such as 

rapid infiltration basins or shallow wells without 

advanced treatment beyond tertiary treatment.

In this case, reuse was not implemented as an effluent 

disposal method (the city has no wastewater treatment 

plant), but rather as a water supply and saltwater 

intrusion abatement tool, making this program different 

from reuse projects that cover the cost of their 

program as part of effluent disposal. The use of 

reclaimed water as a resource means its benefit must 

be evident to the public as a protective and 

sustainability measure. 

Successes and Lessons Learned

The most important lesson learned is that public 

outreach and marketing is critical to the success of the 

project. Utility staff are usually technically and 

scientifically oriented and many are not adept at 

communicating with the general public. Having a third 

party communicate utility issues often helps the public 

accept the validity of the information.

Another lesson learned is that reuse as a water 

resource is the key to a city’s future growth and 

development. Some interests attempt to limit the 

expansion and use of reclaimed water in order to limit 

development. Objections raised during a project 

startup may have little to do with the issue described 

by the resident/business owner and more to do with 

restricting growth.

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2012 Guidelines for Water Reuse

Eastern Regional

Reclaimed Water Distribution System

Authors: Victor J. Godlewski Jr. (City of Orlando); 

Greg D. Taylor, P.E., and Karen K. McCullen, P.E., BCEE (CDM Smith)

US-FL-Orlando E. Regional

Introduction 

The city of Orlando, Fla., has completed the longest, 

single reclaimed water project in Florida, representing 

a regional effort to provide reclaimed water throughout 

central Florida. The Eastern Region Reclaimed Water 

Distribution System (ERRWDS) provides public 

access reclaimed water to residential, commercial, and 

industrial users in the city of Orlando, Seminole 

County, Orange County, the city of Oviedo, and the 

University of Central Florida (UCF). The ERRWDS 

distributes reclaimed water, supplied by six 

wastewater utilities, through 35 miles (56 km) of 

transmission pipe, ranging in size from 20- to 48-in 

(50- to 120-cm) diameter. 

Due to the size of the region and the location of WRFs, 

the regionalized system was effectively separated into 

the eastern and western service areas. The eastern 

system, the focus of this case study, serves areas in 

two state Water Management Districts (WMDs), the St. 

Johns River and the South Florida WMDs. For the 

eastern system, the primary source of reclaimed water 

would be provided from the Iron Bridge Regional WRF. 

Through system interconnects, Orange County’s 

Eastern WRF would also be a source of reclaimed 

water.

Project Background

The Central Florida region is one of the fastest 

growing areas in the state; central Florida region’s 

population increased 24.3 percent, while the state of 

Florida’s population increased 17.6 percent from 2000 

to 2010. Almost all of the region’s drinking water is 

obtained from the upper and lower Floridan aquifer 

system. Reclaimed water has been used extensively in 

Florida to reduce potable water demands and stress 

on the Floridan aquifer system. Prior to the existence 

of regional systems like the ERRWDS, many individual 

utilities in central Florida, including the city of Orlando, 

and Seminole and Orange Counties, used reclaimed 

water for domestic irrigation and commercial crops. 

These organizations were often motivated by their 

ability to obtain Consumptive Use Permits (CUP) for 

water withdrawals from the Floridan aquifer; a typical 

requirement of the permit is to participate in 

implementation and advancement of reuse. Thus, to 

reduce potable water demands and provide beneficial 

reuse, the city pursued a strategy that included a 

regional public-access reclaimed water system. The 

city of Orlando took the lead in planning, design, 

construction and operation of the ERRWDS and other 

organizations contributed financially, to secure 

reclaimed water from the system. 

Capacity and Type of Reuse 

Application 

Reclaimed water from the Iron Bridge Regional WRF 

is managed through a permitted 28 mgd (1,230 L/s) 

surface water discharge to the Little Econlockhatchee 

River, a 35 mgd (1,530 L/s) man-made 

treatment/reuse wetland system [US-FL-Orlando

Wetlands], and a 20 mgd (875 L/s) public access 

reuse system. The ERRWDS is ultimately designed to 

transport an annual daily average flow of 24 mgd 

(1,050 L/s) throughout approximately 35 miles (56 km) 

of pipe, accounting for a peak hour flow factor of 4.5. 

An additional component of the ERRWDS is an inline 

booster pump station to deliver water from the north 

portion of the system to the south portion of the 

system, with a firm pumping capacity of 21 mgd (920 

L/s). There is also a plan to construct a 10 million 

gallon (38,000 m3

) storage and re-pump facility in the 

southeast portion of the city of Orlando in order to feed 

the growing population and help attenuate the peak 

demands. 

Water Quality Standards and 

Treatment Technology 

The permitted capacity of the Iron Bridge WRF is 40 

mgd (1,750 L/s). Although the majority of the 

wastewater treated by the Iron Bridge WRF is from the 

city of Orlando, flows are contributed from other 

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sources, including parts of the City of Winter Park, the 

city of Maitland, the city of Casselberry and 

unincorporated portions of Seminole County. The 

treatment process is a 5-stage biological nutrient 

removal (BNR) system, designed to produce an 

effluent, after clarification and filtration, with the 

following characteristics expressed as annual average 

concentrations (total suspended solids is a maximum): 

 Carbonaceous Biochemical Oxygen Demand 

(CBOD5): 4.28 mg/L

 Total Suspended Solids: 5 mg/L

 Total Nitrogen: 3.08 mg/L

 Total Phosphorus: 0.75 mg/L

Project Funding and Management 

Practices 

The city of Orlando obtained grants from the EPA and 

the St. Johns River WMD, and loans through the 

FDEP State Revolving Fund and bond issuance. This 

allowed for low interest rate loans to fund design and 

construction of the facilities. The total design cost was 

$6.5 million and the projected construction cost of the 

Iron Bridge Regional WRF improvements, the 

supplemental ERRWDS pipeline, inline booster pump 

station, ground storage tank and re-pumping facility, 

and other facilities was approximately $47.5 million. 

To help with project management and oversight, the 

ERRWDS pipeline and treatment plant improvements 

were broken up into multiple construction contracts 

allowing staging the work, lessening the impact on 

local ratepayers. Staging construction also allowed 

more stakeholders to be engaged during the process 

and permitted neighborhoods along the path to be 

connected to during construction, minimizing 

disturbances.

Project Success

The core success of this project is the collaborative 

effort of multiple reclaimed water utilities and potable 

water utilities in a regional project for the economic, 

environmental, and social benefit for all. Potable water 

from the Floridan aquifer is becoming a scarce 

resource, fostering competition between potable water 

utilities for access (permits) to utilize this precious and 

least expensive option for potable water. The potable 

water utilities (most of which are also reclaimed water 

providers) have permit conditions requiring them to 

incorporate reclaimed water in their supply plans for 

domestic and commercial irrigation. Collaboration 

among potable water utilities, reclaimed water utilities 

and water management districts, focused by the city of 

Orlando, allowed reclaimed water to be transported 

across political boundaries (WMD boundaries and 

county boundaries), cost-sharing from multiple 

reclaimed water and potable water suppliers, and 

created a win-win solution to delivering reclaimed 

water for all stakeholders.

Lessons Learned

A regional approach to solve a regional water supply 

problem can be a cost-effective way for stakeholders 

to benefit from cooperation. The project sponsor or 

leader must be willing to thoughtfully consider each 

stakeholder’s unique needs and concerns and to 

develop a plan that attempts to address stakeholder 

issues. Creating a successful regional project thorough 

a master plan that identifies potential customers, 

construction routes, funding sources, and an 

implementation schedule requires each of the 

stakeholders to understand their individual systems. 

This allows accurate demand projections and in turn, 

better estimates on the amount of reclaimed water 

they so that appropriate system sizing can be planned 

for long-term benefits without additional costs; it also 

allows fair cost-sharing on a capacity basis.

Prompt, regular communication and collaboration 

between utilities, regulators, the general public, 

consultants, and contractors allowed participants to 

weigh-in as on the scope and planning of the project. 

Therefore, collective agreement on the final design 

was easier to obtain and construction was easier to 

manage. Each stakeholder had input into the planning 

of the reclaimed water system, with the overall 

decision of the design and construction of the pipeline 

resting with the city of Orlando. 

Finally, public awareness of construction and 

availability of reclaimed water proved to be an 

invaluable asset. By informing the general public of the 

construction activities, better and more productive 

lines of communication, it was easier to anticipate 

possible issues and resolve the many of them prior to 

construction.

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2012 Guidelines for Water Reuse

Economic Feasibility of Reclaimed Water to Users

Authors: Grace M. Johns, PhD (Hazen and Sawyer) and C. Donald Rome, Jr.

(Southwest Florida Water Management District)

US-FL-Economic Feasibility

Project Background and Goals 

Reclaimed water can be an effective way to diversify 

Florida’s water resources in order to use fresh water 

more efficiently. The Southwest Florida Water 

Management District (District) developed evaluation 

criteria and a decision support model called “The 

Reclaimed Water Benefit-Cost Calculator for Irrigation 

and Industrial Applications,” which is being used by the 

District to assess economic feasibility of reclaimed 

water in various applications. 

Reclaimed water is economically feasible if the present 

value of reclaimed water benefits is comparable to or 

greater than the present value of reclaimed water 

costs to the user. The model guides potential users in 

collecting and assembling the necessary information 

and provides estimates of benefits, costs, and net 

benefits. The model can be used to conduct sensitivity 

analyses to evaluate uncertainties in the input data 

and can evaluate partial offsets, where a portion of the 

next available water source is replaced with reclaimed 

water.

Evaluation criteria in the model were developed from a 

survey of 37 reclaimed water users in Florida including 

farmers using reclaimed water for crop irrigation; golf 

courses and a homeowner association using 

reclaimed water for turf, lawn, and landscape irrigation; 

and industries using reclaimed water primarily for 

cooling. Ninety-seven percent of the respondents were 

either very satisfied or satisfied with reliability of their 

reclaimed water supply and 86 percent and 

84 percent, respectively, were either very satisfied or 

satisfied with water quality. The survey responses 

Table 1 Benefits of reclaimed water for irrigation and industrial applications (Survey Results)

Reclaimed Water Benefits (a)

Respondents Who Said Yes to Benefit

Number Said 

Yes

% of 

Responses

Total No. of 

Respondents (b)

1. Have a guaranteed and reliable water source 25 68% 37

2. Able to conserve fresh water for their other uses 25 68% 37

3. Able to irrigate more frequently 17 63% 27

4. Able to apply more water to the crop/lawn/ landscape 15 56% 27

5. Better able to supply water to crops during drought 5 50% 10

6. Irrigation or water costs are lower 17 46% 37

7. Our permitting requirements have been reduced 3 30% 10

8. Net income is higher than with traditional water source 11 30% 37

9. Fertilization costs are lower 7 26% 27

10. Revenue is higher than with traditional water source 9 24% 37

11. Business increased during fresh water restrictions 4 24% 17

12. Better able to protect crops from freezing 2 20% 10

13. Crop yield or product quantity has been higher 2 10% 20

14. Pounds of juice per acre is higher 1 10% 10

15. Our production cost is lower 1 10% 10

16. Water storage costs are lower 3 8% 37

17. Quality of crop/lawn/landscape/product is higher 3 8% 37

(a) All changes are relative to the freshwater source.

(b) Total number of respondents is: 37 if the question was asked of all respondents; 27 if the question was asked of the Agricultural and 

Recreation / Aesthetic respondents; 20 or 10 if the question was asked of the Agricultural respondents and/or the Industrial 

respondents, respectively.

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demonstrated that there are cost-savings and valueadded benefits of reclaimed water use. Benefits are 

listed in Table 1 in order of importance, with the top 

five benefits being that more water is available when 

needed relative to fresh water sources. Additional 

details of the survey results are provided in Table 1. 

Benefits of Reclaimed Water Use 

Survey results were used to validate the model, which 

provides guidance in estimating benefits of reclaimed 

water to the user relative to the next available water 

source (NAWS), which include:

1. Nitrogen fertilizer cost savings - annual.

2. Change in value of crop production - annual.

3. Value of change in quality of crop, lawn, and/or 

landscape - annual.

4. Value of additional water available from the 

reclaimed water source - annual.

5. Value of additional water “freed up” by the 

reclaimed water use - annual.

6. Value of water available during NAWS water 

shortage restrictions - annual.

Costs of Reclaimed Water Use 

The model compares costs associated with accessing 

and using reclaimed water to those from using the 

NAWS. There are potentially three costs associated 

with using reclaimed water: (A) installation costs; 

(B) annual operations and maintenance (O&M) costs; 

and (C) recurring non-annual O&M costs (Table 2). A 

reclaimed water user will not necessarily need to 

spend money on all of these cost items. The model 

directs the user to enter costs relevant to their 

potential reclaimed water use, and relative to using the 

NAWS. It reminds the user to consider the need and 

cost for a backup water supply when reclaimed water 

is not available.

Table 2 Costs of reclaimed water for irrigation and industrial applications

Potential Initial Costs

1. Install pipes to connect system to reclaimed water pipeline

2. Install pressure regulating valves to control water pressure 

3. Install water meter 

4. Install storage pond or tank and pump station 

5. Disconnect existing water source from system 

6. Install or expand the water pretreatment system (industrial applications)

7. Install or upgrade filtration and/or chemical injector systems to reduce micro-jet and drip emitter clogging

8. Create disposal area when reclaimed water flows are higher than crop water needs

9. Change plant material to more salt tolerant species

10. Costs associated with the provision of water from the existing water source for other uses due to the reclaimed water 

connection

Potential Operations and Maintenance Costs, Annual and Recurring, Non-Annual

11. Reclaimed water payment to the utility

12. Maintain water meter, pipeline, pump and storage pond; repair pipeline due to fluctuating water pressure; repair or 

replace rusty controllers, power boxes and equipment

13. Fertilizer management including water quality and plant tissue testing and nutrient evaluations

14. Salinity and pH management including chemical applications, water blending, soil leaching and mechanical means

15. Pest or algae management including cleaning or repairing nozzles, water chlorination, pesticide applications, and filter 

replacement

16. Chemicals needed for reclaimed water treatment prior to industrial application

17. Recording water data and providing reports to regulatory agencies

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Economic Feasibility of Reclaimed 

Water 

Given the data provided by the user, the model 

provides the following results:

 Total benefit in dollars (other than cost savings) 

relative to next available water source: Annual 

and per 1,000 gallons

 Total cost in dollars, including cost savings, 

relative to NAWS: Annual and per 1,000 gallons

 Net benefit (benefit minus cost) of reclaimed 

water use relative to NAWS: Annual and per 

1,000 gallons 

A partial screen shot of the model is provided in 

Figure 1, showing the portion of the model that 

provides nitrogen fertilizer cost savings. The greenshaded cells indicate that information is provided by 

the user. The dark blue-shaded cell indicates that the 

data came from a public source, specified in the 

model. The light blue-shaded cells contain values 

calculated by the model.

Summary

The Economic Feasibility report and model are 

available on the District’s website (SFWMD, n.d.). The 

model assists water users and the District in 

evaluating economic feasibility when a water use 

permittee or applicant is required to consider the use 

of reclaimed water. This would be the case where 

reclaimed water is available from a wastewater 

treatment plant located in a water resource caution 

area. The model results are viewed in the proper 

context of all other information submitted and relevant 

to the water use permit application or renewal.

References

Southwest Florida Water Management District (SFWMD). 

n.d. Retrieved on Sept. 4, 2012 from

<http://www.swfwmd.state.fl.us/permits/wup/>.

Figure 1

Partial screen shot of reclaimed water benefit cost calculator for irrigation, nitrogen fertilizer cost 

savings module

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2012 Guidelines for Water Reuse

Reuse at Reedy Creek Improvement District

Author: Ted McKim, P.E., BCEE (Reedy Creek Improvement District)

US-FL-Reedy Creek

Project Background or Rationale 

Reedy Creek Improvement District (RCID) is a special 

district in central Florida that serves the Walt Disney 

World resort with municipal services, including water 

supply, wastewater treatment, and reuse. Reuse has 

been practiced since the early 1970s, and began with 

irrigation of a tree farm and nursery operations, 

utilizing 2 to 3 percent of the effluent. From that 

modest beginning, reuse practices have grown and 

today RCID practices 100 percent reuse, and has 

done so for over 20 years. Reclaimed water meets the 

majority of irrigation demands of the Walt Disney 

World resort, and is used for cooling tower makeup, 

wash down of sidewalks and streets, fire protection 

and fire suppression, vehicle washing, dust control, 

clean up, and process uses at the treatment plant and 

solid waste transfer station. Reuse currently provides 

between 25 and 30 percent of the total water supply 

needs of the District, and meets a majority of the nonpotable demand, typically between 5 and 6 mgd.

The primary reason for instituting reuse stemmed from 

a climate of conservation and sustainability and 

regulatory desires. In the 1980s, Florida Department of 

Environmental Protection (FDEP) encouraged utilities 

to reuse as a means of reducing surface water 

discharges. Additionally, planning projections indicated 

that traditional water supplies would be unable to meet 

future demands unless alternative sources were 

utilized. Finally, most utilities also discovered that 

reuse was a cost-effective means of meeting both of 

these needs. 

Capacity and Type of Reuse 

Application 

RCID employs a treatment plant with a 15 mgd 

(657 L/s) capacity. Reclaimed water is provided to two 

reuse systems, one with a 10 mgd (438 L/s) capacity 

and a rapid infiltration basin system (RIB) of 12.5 mgd 

(548 L/s). The reuse system capacities exceed plant 

capacity to meet variations in demand due to distinct 

wet and dry seasons. The reuse systems consist of a 

distribution system with about 80 miles (129 km) of 

pipeline, a pump station, and reservoirs with 15 million 

gallons (56,800 m3

) of storage capacity. Reclaimed 

water is used principally for landscape with over 

80 percent of irrigated areas within RCID using 

reclaimed water (Figure 1). When the supply of 

reclaimed water exceeds demand, reclaimed water is 

used to recharge groundwater through the RIB 

system, which consists of 85 1-ac (0.4-ha) basins 

constructed in a sandy ridge area located 2 to 3 miles 

(3.2 to 4.8 km) from the plant site. The USGS 

conducted studies in the early 1990s concluding that 

approximately 70 percent of water applied to the RIBs 

reaches the Upper Floridan aquifer and the balance 

diffuses to the surficial aquifer. The Upper Floridan 

aquifer is the primary source of drinking water for 

much of central Florida.

In a typical year, flow is split about equally between 

the two systems but is weather dependent. In dry 

weather, demand on the distribution system increases 

(typically peaking in April and May); some 

augmentation with groundwater is typically required to 

supplement flows in the reclaimed water distribution 

system during dry weather to meet peak demands. In 

Figure 1

Areas irrigated with potable water and RCID 

reclaimed water (Photo credit: Reedy Creek Energy 

Services Surveying and Mapping Department)

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wet weather, demand on the distribution system drops 

and flow is diverted to the RIBs, which are used almost 

exclusively during storms and hurricane events. 

Figure 2 shows the historical distribution of flow 

between the RIBs and reuse distribution system 

(values are shown as annual averages).

Water Quality Standards and 

Treatment Technology 

RCID employs a five stage BardenphoTM process for 

carbon and nutrient removal, followed by filtration and 

chemical disinfection (hypochlorite solution) to achieve 

a water quality suitable for public access reuse 

purposes per Chapter 62-610 of the Florida 

Administrative Code. 

Annual testing of the reclaimed water shows that it 

typically meets USEPA primary and secondary 

drinking water standards, with one exception for 

TTHMs (Table 1). The reclaimed water also meets the 

targeted thresholds for protozoan parasites (giardia

and cryptosporidium) as recommended by FDEP 

(5 ocysts/100 mL). The facility operates under an 

FDEP permit because the facility is a zero-discharge 

operation, and does not have an NPDES permit.

Project Funding and Management 

Practices 

The reuse distribution system is operated much like a 

typical water distribution system, and matches the 

pressures in the potable system, which facilitates 

conversions. Reclaimed water is metered, invoiced,

and monitored similar to potable water, and the 

distribution system is constructed using similar 

standards for materials, installation, and testing. 

Chloride concentrations in the reclaimed water are 

typically an order of magnitude higher than the potable 

water (>120 mg/L versus 10 mg/L) and this marked 

difference is used in the field as an aid in identifying 

the source of the water during leak detection 

procedures. Indicator test strips are used for 

determination of chloride levels. All reclaimed water 

piping is color-coded using purple (Pantone #522C); 

plastic pipe is pigmented and other pipe materials are 

striped with paint, tape, or both. Buried pipe is installed 

with identification tape. Additionally, all above, or atgrade appurtenances, are identified with purple 

coloring and purple and yellow markers and tags, 

including fire hydrants. RCID employs a robust 

backflow prevention and cross connection program to 

ensure that reclaimed and potable water systems are 

not inadvertently cross connected. RCID also requires 

all new development to connect to the reclaimed water 

system for non-potable uses.

Institutional and Cultural 

Considerations 

Sustainability has been a driving force for use of 

reclaimed water for non-potable uses and for aquifer 

recharge at RCID. The realization that the Upper 

Floridan aquifer is a finite and precious resource has 

led to its conservation, which in turn has fostered 

growth of reuse as an alternative water supply. As a 

result, reclaimed water is an accepted and desired 

utility, and has gained increasing acceptance as a 

valuable resource.

Successes and Lessons Learned

The reuse system employed by RCID has reaped 

many benefits and has undergone transformation in its 

40-year history. Initially employed as a means of 

ceasing surface water discharge, it has evolved into an 

alternative water supply and a means of achieving a 

higher level of sustainability by returning a significant 

portion of the consumed water to its source, in effect 

practicing indirect potable reuse. The reuse distribution 

system and related consumption has allowed RCID to 

remain within its Water Use Permit, which limits the 

amount of groundwater that can be withdrawn). The 

recharge of the aquifers by the RIBs has also allowed 

the net withdrawal of groundwater at RCID to remain 

relatively constant over the past 20 years, despite a 

more than doubling of growth and development within 

the service area.

Figure 2

Allocation of reclaimed water to RIBs and reuse 

distribution system

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Table 1 Water quality characteristics of RCID effluent (2007 – 2011) compared to drinking water standards

Parameter Units 2007 2008 2009 2010 2011

Drinking Water 

Standard

Inorganics

Arsenic mg/L <0.0015 <0.0015 <0.0015 <0.0015 <0.0015 0.05

Barium mg/L <0.0025 0.0028 0.0035 0.0015 0.0015 1

Cadmium mg/L <0.00038 <0.00038 <0.00038 <0.00038 <0.00038 0.01

Chromium mg/L <0.006 <0.006 <0.006 <0.006 <0.006 0.05

Flouride mg/L 0.31 0.08 0.19 0.03 0.02 4

Lead mg/L <0.00054 <0.00054 <0.00054 <0.00054 <0.00054 0.05

Mercury mg/L <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 0.002

Nitrate as N mg/L 0.391 0.57 0.664 0.688 0.402 10

Selenium mg/L <0.0015 <0.0015 0.0018 <0.0015 <0.0015 0.01

Silver mg/L <0.0005 <0.0001 <0.0001 <0.0001 <0.0001 0.05

Sodium mg/L 160 73.8 71.9 82.3 77.9 160

Volatile Organics

Ethylene dibromide 

(EDB) μg/L <0.01 <0.006 <0.009 <0.009 <0.0081 0.02

Para-dichlorobenzene μg/L <1.0 <1.0 <1 <0.1 <1 75

Vinyl chloride μg/L <0.5 <0.5 <0.5 <0.083 <0.71 1

1,1 -dichloroethane μg/L <0.5 <0.5 <0.5 <0.15 <0.5 7

1,2-dichloroethane μg/L <0.5 <0.5 <0.5 <0.082 <0.5 3

1,1,1-trichloroethane μg/L <0.5 <0.5 <0.5 <0.00015 <0.5 200

Carbon tetrachloride μg/L <0.5 <0.5 <0.5 <0.082 <0.5 3

Trichloroethane μg/L <0.5 <0.5 <0.5 <0.068 <0.55 3

Tetrachloroethane μg/L <1.0 <1.0 <1.0 <0.099 <1.0 3

Benzene μg/L <0.5 <0.5 <0.5 <0.05 <0.58 1

Trihalomethanes

Total Trihalomethane 

(TTHM) μg/L 66.7 59.4 179** 46.5 54.2 80

Organics

Endrin μg/L 0.021** <0.02 <0.019 <0.003 <0.01 0.02

Lindane μg/L 0.097 0.03 <0.025 <0.0031 <0.005 4

Methoxychlor μg/L <0.0021 <0.02 <0.024 <0.024 <0.019 100

Toxaphene μg/L <0.090 <0.09 <0.09 <0.00022 <0.96 5

2,4-D μg/L <0.12 0.32 <0.091 <0.099 <0.037 100

2,4,5-TP (Silvex) μg/L <0.11 <0.087 <0.056 <0.05 <0.06 10

Radiologicals

Gross Alpha pCi/L <2.1 <1.6 <1.3 1.3 1.6 15

Radium 226 and 228 pCi/L 0.75 0.2 0.7 0.7 0.8 5

Secondary Chemistry

Chloride mg/L 104 142 166 110 114 250

Copper mg/L 0.0021 <0.0015 0.0015 <0.0015 0.0015 1

Iron mg/L 0.12 0.13 0.1 0.15 0.16 0.3

Manganese mg/L 0.0038 <0.0015 0.0017 <0.0015 <0.0015 0.05

Sulfate mg/L 50.9 60.3 53.9 55.3 47.1 250

Zinc mg/L <0.025 <0.025 0.025 <0.025 0.025 5

pH (units) mg/L 7.4 6.2 7.5 7.6 8.15 6.5 - 8.5

Total Dissolved Solids mg/L 391 410 419 402 414 500

Foaming Agents mg/L 0.045 <0.006 0.021 0.059 0.12 0.5

mg/L are milligrams per liter or parts per million

μg/L are micrograms per liter or parts per billion

pCi/L are picoCuries per liter

BDL means below the detection limit of the analysis technique employed

** Indicates sample parameters that did not meet or exceeded the drinking water standard

N/A indicates that an average value was not possible to calculate due to a mix of results above and below detection 

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2012 Guidelines for Water Reuse

Marco Island, Florida,

Wastewater Treatment Plant

Authors: Jennifer Watt, P.E. (General Electric); Solomon Abel, P.E. (CDM Smith); and 

Rony Joel, P.E., DEE (AEC Water)

US-FL-Marco Island

Project Background

The City of Marco Island, Fla., is located in southwest 

Florida among the 10,000 islands that are part of the 

Florida Everglades. This resort community population 

varies from 17,000 in summer to 40,000 in winter. The 

majority of Marco Island was man-made in the late 

1960s to early 1970s, by filling mangrove and swamp 

areas, and creating a back yard canal system. 

The Marco Island Wastewater Treatment Plant 

(WWTP) is about 40 years old and the original 

treatment technology has been expanded in phases to 

accommodate its growing community. Originally, 

wastewater treatment consisted of onsite residential 

septic tanks and a 3 mgd (130 L/s) central sewage 

treatment plant for condominium and commercial 

facilities. In 2005, the city initiated a 7-year residential 

septic tank replacement program. In an effort to 

protect the clean Gulf of Mexico waters that lap the 

local beaches and draw tourists and winter residents, 

city officials launched a 7-year plan to phase out all 

septic systems.

Capacity and Treatment Technology

In 2003, Marco Island Utilities selected a packaged 

membrane bioreactor (MBR) system to upgrade the 

existing contact stabilization process and increase 

treatment capacity. Because the existing plant is 

surrounded by water, commercial facilities, and other 

utilities, little room is available for expansion and an 

increase in capacity with conventional technology 

would not have been possible.

The MBR process offered a high level of treatment for 

producing reclaimed water in a small footprint by 

eliminating secondary clarifiers and tertiary filtration 

systems required in conventional treatment. The 

treatment capacity in 2012 is 3.5 mgd (150 L/s); 

projections of population growth and septic tank 

conversions are anticipated to result in a wastewater 

demand on the island of 5.0 mgd (220 L/s). 

The existing contact stabilization process was 

upgraded in multiple phases to minimize interruptions 

of treatment operations, stage funding requirements,

and ease of constructability. The first phase added the 

MBR treatment process in four trains and kept part of 

the contact stabilization process in operation. In the 

second phase of the project, the remaining contact 

stabilization plants were taken out of service. A second 

bioreactor tank with anoxic and aerobic volume to 

match the existing tank was installed, as well as a fifth 

membrane train to provide a total capacity of 5 mgd 

(220 L/s) with one standby membrane train (Figure 1). 

Final disinfected water flows to a pump-station wet 

well for transfer to two onsite 0.5-million-gallon 

(1,900 m3

) storage tanks. Reclaimed water is used to 

irrigate the Marco Island, Hideaway Beach, and Marco 

Shores golf courses or sent to an onsite deep-injection 

well when reclaimed water demands have been met. 

The MBR system produces effluent exceeding Marco 

Island discharge requirements and provides highquality reuse water, reducing the demand of potable 

Figure 1

Marco Island WWTP membrane trains (Photo credit: 

Jeff Poteet) 

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Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

supplies by creating a continuous drought-proof supply 

for golf course and residential property irrigation.

Project Funding and Management 

Practices 

A challenge to the new system was financing the 

expansion project. The original system was financed 

by users; each condominium that connected was 

allocated a capital cost and provided a 10-year finance 

plan. Those that joined the system were guaranteed a 

$0.52/1,000 gallon ($0.14/m3

) cost for the 10-year 

period. 

It was important not to burden consumers that were 

not going to receive direct benefits of using irrigation 

water. The indirect benefit is that the size of the water 

plant capacity expansion could be reduced by the 

volume of reuse water that is distributed, saving all 

water utility customers the cost of plant expansion. 

The reuse system expansion cost was $1.6 million; 

$750,000 of funding was a grant award from Big 

Cypress Basin, a component of South Florida Water 

Management District. The balance of the project was 

paid for by condominiums connecting to the system. 

The city mandated that all condominiums adjacent to 

the reuse system must connect to the system within 

365 days to provide cost recovery. Based on the cost 

to be recovered and the volume of water used for 

irrigation by each condominium, the cost per 

1,000 gallons (3.8 m3

) of the reuse water was the 

same as the potable water for 24 months. At the end 

of this period, the cost of reclaimed water was reduced 

to the same rate as all other reuse water customers 

(40 percent of the potable water rate). The FY12 cost 

for reuse is $1.56/1,000 gallons ($0.41/m3

).

The FY2012 potable water cost is:

 Base rate - $30.89

 Use rate - $3.85/1,000 gallons ($1.01/m3

) 

The FY2012 wastewater cost is:

 Base rate - $25.14

 Use rate - $4.97/1,000 gallons ($1.31/m3

) 

Institutional/Cultural Considerations 

The biggest cultural challenge was for operations staff 

at Marco Island Utilities to transition from operating a 

contact-stabilization facility to MBRs. Monitoring the 

biological process and amount of settling in the clarifier 

was the measure of performance for the original 

system. Operators had to learn how to monitor the 

membrane system and view the biological process in a 

different light—important for optimization but not in 

relation to settling and treatment quality. The transition 

required a comprehensive training program and extra 

attention to automation and controls, including the 

creation of a new position devoted to instrumentation 

and controls. All the team members were trained 

extensively in the new process and were closely 

involved with the construction before MBR start-up. 

A public education program was developed to 

demonstrate the benefits of expanding the system and 

reducing use of potable water for irrigation. The per 

capita water consumption is approximately 450 gallons 

(1.7 m3

) per day on Marco Island. Considering interior 

consumption is approximately 110 gpcd (0.4 m3 per 

capita per day), the majority of water is used for 

irrigation. 

No single family homes have access to reuse water, 

which became an issue, as these customers wanted 

access to the low cost irrigation water. The challenge 

to meet this demand is twofold: first, the supply of 

reuse water is dependent on the volume of wastewater 

generated, and second, a distribution system does not 

exist. Based on interior residential water consumption, 

approximately four full-time occupied homes would 

generate the volume required to irrigate one home. In 

addition to not having available product, the cost to 

install new irrigation lines would be approximately 

$6,000 per residential site resulting in a 10-year 

recovery for the capital investment.

Successes and Lessons Learned

The biggest success of the project was the expansion 

of the existing WWTP from 1 to 3 mgd (44 to 130 L/s) 

with only the addition of membrane trains. Use of 

membranes required only a small additional footprint 

so that the plant could be expanded on the existing 

site. Modular expansion with additional membrane 

trains to 5 mgd (220 L/s) allowed for phased 

construction to match increases in capacity demands, 

funding, and schedule requirements including 

construction activity scheduling between the rainy 

season (May to August) and the arrival of winter 

residents around the beginning of January. 

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References

Joel, R., B Weinstein, J. Poteet, S. Abel, S. Haecker and J. 

Watt. 2008. “No Space? No Problem!” WE&T. 

Abel, S., A.R. Joel, B. Weinstein, P Tunnicliffe and W. 

Kimball. 2008. “Implementation of the Largest Package MBR 

WWTP.” SEDA/AMTA.

Watt, J. 2006. “Marco Island Welcomes Recycled Water.” 

Membrane Technology. 

Force, J. 2010. “Learning New Tricks.” Treatment Plant 

Operator. 

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2012 Guidelines for Water Reuse

Everglade City, Florida

Author: Rony Joel, P.E., DEE (AEC Water)

US-FL-Everglade City

Project Background or Rationale 

The city of Everglade City, Fla., is a small fishing 

community in the southernmost portion of Collier 

County on the western coast of Florida (Figure 1). The 

city is the interface to Big Cypress Swamp with coastal 

wetlands lining the north coast of Chokoloskee Bay. 

This highly sensitive estuarine, shallow water region is 

part of the “Ten Thousand Island” area that is known 

to be a vital part of the ecology of Southern 

Everglades National Park, and is home to many 

species of birds, fish, and other wildlife. The outer 

portions of the city are characterized by mangrove 

wetlands.

The city has a total of 250 single family residential 

homes and 130 mobile home units. At build-out 

(2030), an additional 482 home units will be added. 

The current population of the city is approximately 800. 

Figure 1

Location of Everglade City (Photo credit: Collier County, Fla. Appraiser)

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The city has developed areas that are at an elevation 

of 2 to 5 feet (0.6 to 1.5 meters). Because of the low 

elevation, the city and surrounding areas experience 

tidal and storm surge flooding.

Capacity and Type of Reuse 

Application 

The Everglades City wastewater treatment system 

provides service to the incorporated area of the city 

and to portions of Copeland and Chokoloskee. The 

existing plant has a capacity of 0.16 mgd (7 L/s) on an 

annual average daily flow basis.

The treatment process consists of flow equalization, 

aeration, secondary clarifications, membrane filtration, 

chlorination, dechlorination, aerobic sludge digestion, 

sludge drying beds, reject storage, reclaimed storage 

and distribution, and surface water discharge. Flow is 

delivered to the plant via 245 grinder pump stations in 

the city and two master pump stations (Copeland and 

Chokoloskee). 

The city has two permitted options for land application 

of reclaimed water. The first option is for distribution or 

reclaimed water for public reuse for irrigation of 

residential lawns, city landscape areas, roadway 

medians, the airport, school, and park. If the demand 

for reclaimed water is less than the total production of 

reclaimed water, the remaining water is used to 

recharge the local shallow aquifer through a rapid 

infiltration basin. 

Water Quality Standards and 

Treatment Technology 

The Florida Department of Environmental Protection 

operating permit mandates the following annual 

average treatment standards:

 biochemical oxygen demand, Carbonaceous 5 

day – 20 mg/L

 total suspended solids – 5 mg/L

 coliform – 25 #/100 mL

 pH – 6.0 min to 8.5 max

 chlorine residual – 1 mg/L

 total nitrogen – no limit 

 total phosphorous – no limit

The monitoring is required at the following locations: 

after chlorination, but before dechlorination, at the 

discharge point to the percolation ponds, and at the 

discharge point to the public access reuse system. 

Project Funding and Management 

Practices 

The city distributes reuse water at no cost to their 

customers. The average monthly cost of potable water 

(base and use fee) for a user of 4,000 gallons (15 m3

) 

is $17; this typically reflects a $13 base fee that

includes 3,000 gallons (11 m3

) of water and $4/1,000 

gallons ($1.03/m3

) for use above the base volume. 

The monthly wastewater treatment cost for the same 

level of service is $16.20 ($13 base fee plus 

$3.20/1,000 gallons ($0.83/m3

) above 3,000 gallons 

(7.74 m3

) water use).

The current wastewater plant is at the end of its useful 

life. The city is evaluating the need to upgrade the 

plant for full build out and increasing their service area. 

The total flow at build out is estimated to be 0.50 mgd 

(22 L/s). At this flow, new use opportunities for the 

generated reuse water will need to be established. 

The city's current customer base cannot sustain the 

projected needs without a rate increase. A consultant 

has determined to meet the current 5-year capital 

improvements plant, and would require a rate increase 

in excess of 100 percent over the next 3 years. To 

reduce the rate impact, the city has started the 

process of applying for grants to reduce the rate 

increase. 

Institutional/Cultural Considerations 

The city of Everglades City has demonstrated that 

small communities can effectively incorporate a reuse 

water system into their effluent disposal scheme and 

not charge a fee for its use. 

Mayor Sammy Hamilton, Jr. stated that: “The only 

negative comments I receive about city operations is 

when our homeowners do not get the reuse water they 

have become accustomed to receiving.” He also 

states, “Our water supply is treated as our community 

life blood and any alternative water source we can 

identify will sustain our community for the next 100 

years.”

The city has landscaped its medians with Florida 

native plantings and as a component of the city 

conservation program; it uses the reuse water to 

irrigate the plantings. Annually the city has a 2-day

seafood festival attended by over 60,000 persons. 

They call commenting how green the city is.

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2012 Guidelines for Water Reuse

City of Orlando Manmade Wetlands System

Author: Mark Sees (City of Orlando)

US-FL-Orlando Wetlands

Project Background or Rationale 

The Orlando Easterly Wetlands is an effort by the city 

of Orlando to enhance the environment with highly 

treated reclaimed water from its 40-mgd (1,750 L/s) 

Iron Bridge Regional WRF. The project began in the 

mid-1980s when the city, faced with the need to 

expand its permitted treatment capacity, was unable to 

increase nutrient discharge into sensitive waterways. 

Nitrogen and phosphorus were of concern because 

Florida water bodies are particularly susceptible to 

algae blooms, as a result of nutrient loading; these 

blooms can deplete oxygen and result in fish kills and 

other undesirable conditions during periods of very low 

flows that occur in the summer.

At its inception, there were no existing large-scale 

wetland treatment systems to serve as an example for 

city environmental services staff, consultants, or state 

regulators. But with the cooperation of all parties, work 

began on a 1,200-ac (485-ha), created wetland to 

provide nutrient removal for 20 mgd (876 L/s) of 

reclaimed water from the Iron Bridge facility. The 

Orlando Easterly Wetlands (OEW) site is located in 

east Orange County, Fla., approximately 2 mi (3.2 km) 

west of the main channel of the St. Johns River. 

Surveys performed in 1848 indicate that the site had 

once been a wet prairie, with smaller areas consisting 

of hardwood swamps and hammocks.

During the early to mid-1900s, land was ditched and 

drained for agricultural development; the ditches and 

swales that drain this site discharged directly into the 

St. Johns River. The drainage system had also 

lowered the groundwater table and transported runoff 

to the St. Johns River so that wetland vegetation could 

no longer be sustained throughout the site.

Water Quality Standards and 

Treatment Technology 

Recognizing that aquatic ecosystems could be used to 

naturally remove nitrogen and phosphorus, the city 

used this site to create the large-scale wetland 

treatment system. Earthen berms were constructed, 

and 2.1 million aquatic plants were planted in 17 cells 

to "polish” reclaimed water that filters through the 

wetlands. Water is collected and discharged into the 

St. Johns River with no adverse impact. Creation of 

the wetland treatment system allowed the city to meet 

treatment and disposal needs, reclaim a vital wetland, 

and create valuable habitat for wildlife. The OEW has 

been continuously monitored through a Domestic 

Wastewater Operating Permit, which includes 

regulated daily, weekly, monthly, and annual water 

quality standards as shown in Table 1. 

Table 1 Permit limits and wetlands performance in 2011

Parameter

Monthly/Annual 

Limit

2011 Wetlands 

Discharge

pH 6.0 – 8.5 s.u. 7.24 s.u.

Total Suspended 

Solids 15.0 mg/L 1.07 mg/L

Total Nitrogen 2.31 mg/L 1.00 mg/L

Total Phosphorus 0.20 mg/L 0.026 mg/L

Carbonaceous 

Biochemical 

Oxygen Demand

10 mg/L 0.67 mg/L 

Dissolved Oxygen 3.8 mg/L 4.9 mg/L

Institutional/Cultural Considerations 

In addition to providing outstanding water quality, the 

Easterly Wetlands is open as a park for passive 

recreation. Each year more than 12,000 people visit 

the park enjoying hiking, jogging, bicycling, bird 

watching, nature photography, and horseback riding. 

The park has an educational center where volunteers 

promote the success of the wetland treatment system 

by offering guided tours. Each year, more than 1,600 

people are given personal tours of the system and 5 to 

10 tours are given to delegates and representatives of 

foreign countries who are interested in economical 

alternatives for reuse. 

Successes and Lessons Learned

After more than 2 decades of demonstrated 

performance, the Orlando Easterly Wetlands 

reclamation project has proven that large-scale, 

created wetlands can be used on a long-term basis, 

with resounding success, for the advanced treatment 

of wastewater and beneficial reuse.

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Regional Reclaimed Water Partnership Initiative of the 

Southwest Florida Water Management District

Author: Alison Ramoy (Southwest Florida Water Management District) 

US-FL-SWFWMD Partnership

Project Background or Rationale 

The Southwest Florida Water Management District 

(SWFWMD) is one of five regional water management 

districts directed by state law to protect and preserve 

water resources in its boundaries (Figure 1). The 

district encompasses roughly 10,000 mi2 (26,000 km2

) 

in all or part of 16 west-central Florida counties, 

serving more than 5 million people. The Regional 

Reclaimed Water Partnership Initiative (RRWPI) was 

developed in 2008 to maximize beneficial use of 

reclaimed water, while offsetting groundwater use. As 

part of its Cooperative Funding Initiative, a cost-share 

program for water resources management projects, 

SWFWMD was requested to fund up to half the cost of 

a series of projects that would accomplish these goals.

Several potential concepts were initially proposed and 

after a series of meetings, the partners identified an 

industrial reuse project that would provide the Tampa 

Electric Company (TECO) with reclaimed water to 

offset groundwater use at its Polk Power Station in 

Mulberry, Florida. The location of this project 

(Figure 2) is significant because it is an area with 

depressed aquifer levels, which has caused saltwater 

intrusion, reduced river flows, and lowered lake levels. 

This area is the Southern Water Use Caution Area 

(SWUCA) and the district approved the SWUCA 

Recovery Strategy in 2006 (SWFWMD, 2006). 

Implementation of the strategy will ensure adequate 

water supplies to meet growing demands, while 

protecting and restoring water and related natural 

resources of the area. Among the SWUCA Recovery 

Strategy’s components are alternative supply 

development and permitting. 

The primary source of water supply has been 

groundwater and developing alternative water supplies 

from surface water, reclaimed water and desalination 

will reduce groundwater use, while meeting growing 

water demands. SWFWMD’s permit program requires 

water use permit holders to use alternative water 

sources where economically, technologically, and 

environmentally practical. This longstanding 

commitment to developing alternative water supplies 

along with the permit program has contributed to a 

trend of declining groundwater use in the SWUCA. 

Figure 1

Water management districts and SWFWMD counties

Figure 2

Project location

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Capacity and Type of Reuse 

Application 

This project is a unique public-private partnership that 

will provide TECO with approximately 7 mgd (300 L/s) 

of reclaimed water for industrial cooling and other uses 

for power generation expansion at its Polk Power 

Station. Three sources of reclaimed water have been 

identified. 

The first source to come online will be the city of 

Lakeland’s reclaimed water wetland treatment system. 

Lakeland has two wastewater treatment plants 

(WWTPs) with a combined capacity of 21.7 mgd (950 

L/s) and an annual average flows of 11.5 mgd (500 

L/s) (FDEP, 2010). In 2010, the city’s McIntosh Power 

Plant used 4.79 mgd (210 L/s). The remainder was 

combined with 1.85 blowdown water from the 

McIntosh Power Plant and sent to the 1,400-ac (570 

ha) wetland treatment system. TECO has agreed to 

use approximately 5 mgd (220 L/s) from the wetland 

treatment system, which is currently being discharged 

to the Alafia River and ultimately Tampa Bay. TECO’s 

use of the reclaimed water will offset groundwater use 

and reduce nitrogen loading to Tampa Bay. 

The second source of reclaimed water is the Polk 

County Southwest Regional WWTP. A separate 

transmission main will be constructed from the WWTP 

to connect to the transmission main being constructed 

from the Lakeland wetland treatment system to the 

Polk Power Station. It is anticipated that Polk County 

will initially provide 1 mgd (44 L/s) for use at the Polk 

Power Station, reclaimed water flows could increase to 

2 mgd (90 L/s) by 2030 as wastewater flows continue 

to increase. 

The third source is from the city of Mulberry, with 

approximately 0.5 mgd (22 L/s) of reclaimed water 

initially being provided from its WWTP for use at the 

Polk Power Station. Similar to the Polk County portion 

of the project, a separate transmission main will be 

constructed from the Mulberry WWTP and connected 

to the transmission main from the Lakeland wetland 

treatment system to the Polk Power Station.

Water Quality Standards and 

Treatment Technology 

Water from Lakeland and Mulberry meets advanced 

waste treatment standards required for surface water 

discharge (Section 403.086, F.S.). In addition to high 

level disinfection, the following is required on an 

annual average basis:

 biochemical oxygen demand (BOD) less than 5 

mg/L 

 total suspended solids (TSS) less than 5 mg/L

 Total nitrogen less than 3 mg/L 

 Total phosphorus less than 1 mg/L 

Project Funding and Management 

Practices 

The project is possible, in part, from funding allocated 

by SWFWMD through its Cooperative Funding 

Initiative program. The district and TECO entered into 

an agreement in 2009 for design and construction of 

approximately 15 miles (24 km) of reclaimed water 

transmission main, a pump station, and additional 

treatment. The anticipated cost is $72.7 million, and 

SWFWMD has been requested to reimburse TECO for 

up to half the cost. Because this project is a 

component of the West-Central Florida Water 

Restoration Action Plan, an implementation plan for 

components of the SWUCA Recovery Strategy, 

additional funding in the amount of $3.3 million has 

been allocated from the state. The project is under 

way and construction is expected to be complete in 

2014. 

TECO and the city of Lakeland have entered into a 30-

year service agreement for delivery of reclaimed 

water, which was also a condition of the water use 

permit issued by SWFWMD to the city of Lakeland. As 

a result, the district was able to issue a 20-year water 

use permit to Lakeland. This is significant because 

SWFWMD has generally not issued 20-year water use 

permits for traditional sources in stressed water 

resource areas such as the SWUCA. This set the 

stage for a 20-year water use permit to also be issued 

to Polk County for its Southwest Regional Utility 

Service Area. 

Successes and Lessons Learned

The RRWPI has resulted in a public-private 

partnership enabling TECO to continue plans for 

expansion at its Polk Power Station, while reducing its 

reliance on groundwater for cooling. Reclaimed water 

that will be used will no longer be discharged to

surface waters, also benefiting Tampa Bay by 

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reducing nitrogen loading. Maximizing the beneficial 

use of reclaimed water ensures that the water 

resources of the SWUCA can continue to recover. 

Most importantly, the RRWPI has provided opportunity 

for the partners, and other stakeholders, to identify 

uses for reclaimed water that can offset use of limited 

groundwater supplies, allowing the recovery of the 

resource, while meeting growing water needs.

References

Florida Department of Environmental Protection. 2010. 2010 

Reuse Inventory. 

Florida Statutes. Section 403.086 (4).

Southwest Florida Water Management District. 2006. 

Southern Water Use Caution Area Recovery Strategy.

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2012 Guidelines for Water Reuse

The City of Altamonte Springs: 

Quantifying the Benefits of Water Reuse

Author: David Ammerman, P.E. (AECOM)

US-FL-Altamonte Springs

Reclaimed Water and Potable Water 

Potable water systems experience demands for 

drinking water, car washing, irrigation, and many other 

uses. Design of potable water delivery systems are 

also subject to fire flow requirements, which provide 

capacity in excess of routine water demands. This 

collection of uses and design requirements dilutes the 

impact of any one use on seasonal and diurnal 

patterns associated with that demand; the opposite is 

often true of reclaimed water systems. In many 

nonpotable reclamation systems, reclaimed water is 

used almost exclusively for irrigation and influences of 

irrigation on hourly, daily, and monthly demands 

dominate in these systems.

A second, important difference between potable and 

reclaimed water supplies is the nature of the source. In 

Florida, most utilities derive potable water from 

groundwater sources that are vast with respect to the 

short-term water supply demands. Reclaimed water 

supplies, on the other hand, are limited to wastewater 

flows on a given day. To complicate matters, 

wastewater flows vary considerably throughout a day 

and on an annual basis, and these variations are often 

opposite of variations in irrigation demands.

A 5-year historical water-use record for the City of 

Altamonte Springs in central Florida (Figure 1) shows 

seasonal peaks and valleys typical of municipal water 

demands in the area. However, unlike most cities, 

Altamonte Springs operates an extensive urban reuse 

system and can track water uses by source. The blue 

area at the base of the bar chart reflects average 

monthly potable water demands. Because a majority 

of the city has reclaimed water available for outside 

uses, it is reasonable to assume that potable water 

use that remains is primarily within homes and 

commercial units. The purple area indicates reclaimed 

water flows from the city’s water reclamation facility 

into a dual distribution system for use as irrigation. In 

addition to these two local sources, the city has found 

it necessary to augment its reclaimed water system in 

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Flow (mgd)

Month

Potable Water Reclaimed Water

Supplemental Water (Reclaimed) Supplemental Water(Ground Water)

Figure 1

Average monthly water use by source

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periods of peak irrigation demand to avoid shortages. 

The supplemental water sources include reclaimed 

water from a neighboring utility, raw groundwater 

supplies, and surface water.

It is worth considering the variability in potable and 

reclaimed water demands in the City of Altamonte 

Springs in more detail. Overlays the 5-year average 

monthly demands for both potable and reclaimed 

water are provided in Figure 2. It is apparent that 

seasonal variability in potable water demands is less 

than that in the reclaimed water system, suggesting 

that implementation of an urban reuse system has 

been successful in transferring seasonal variations in 

water demands associated with irrigation from the 

potable water system to the reclaimed water system. 

Undoubtedly, this has resulted in a reduction in the 

maximum-day and peak-hour demands for potable 

water, which in theory could be translated into 

reducing the design criteria used for max day water 

treatment capacity and peak-hour pumping facilities.

Conservation of Potable Supplies 

Given the time, effort, and expense of implementing 

dual distribution projects, consideration for the 

expected gains is warranted. How well do these 

systems work in reducing the use of potable water?

Potable water use in Altamonte Springs, from 1975 to 

2010, (Figure 3) shows a continuous increase until 

1989; the decline in potable demands, despite 

continued population growth corresponds to 

implementation of the dual distribution system. The 

continued decline in demand correlates to expansion 

of the system. The city has also implemented a 

conservation program and by 2010, potable water 

demands were back to 1979 levels, such that the per 

capita use of potable water is currently 30 percent less 

than prior to construction of the reuse system. 

Concurrently, the city was able to reduce the volume 

of effluent discharged to surface waters to 

approximately 20 percent of their flows.

Lessons Learned

Implementation of a dual distribution system within the 

City of Altamonte Springs has allowed the city’s 

potable water demand to reach levels last seen in 

1979, despite an increase in population. The use of a 

dual distribution system has resulted in the reclaimed 

water system bearing the 

majority of the seasonal 

variations in demand, 

which could theoretically 

result in reduced design 

criteria.

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

1975

19771979

1981198319851987198919911993199519971999200120032005

20072009

Annual Average Potable Water Production (mgd)

Prior to Urban Reuse After Urban Reuse 

Figure 3

Potable water use

Figure 2

Comparison of seasonal variations in reclaimed and potable water demands

60%

70%

80%

90%

100%

110%

120%

130%

140%

150%

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Demand Factor*

Reclaimed Water Factor

Potable Water Factor

 

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2012 Guidelines for Water Reuse

Evolution of the City of Clearwater's

Integrated Water Management Strategy

Authors: Laura Davis Cameron, BSBM; Tracy Mercer, MBA;

Nan Bennett, P.E.; and Rob Fahey, P.E. (City of Clearwater Public Utilities)

US-FL-Clearwater

Project Background

Clearwater, a coastal Florida city straddled by Tampa 

Bay and the Gulf of Mexico, distributes potable 

drinking water to more than 110,000 residents and 

nearly 800,000 visitors annually (Clearwater, 2007). As 

a coastal Florida city, only about 33 percent of the 

potable water demand, which was 11 mgd (480 L/s) in 

2010, can be met with local sources; excess demand 

is met by importing water from surrounding counties, 

and purchases from some sources are at a high rate. 

The excess demand is purchased and imported at a 

higher rate from Pinellas County. 

Clearwater realized the need to decrease water 

demand through conservation and use of reclaimed 

water, which also reduces treated wastewater effluent 

discharge to local surface waters. Education and 

incentive programs sparked the genesis of 

Clearwater’s conservation plan, which included lowflow toilet rebates, high-efficiency shower heads, and 

faucets. Education moved to 5th grade classrooms, 

where students learned about conservation and 

brought home conservation devices for family use. 

This multi-level water use and conservation plan was 

the beginning of Clearwater’s Integrated Water 

Management Strategy (IWMS), formally adopted in 

2007 with specific goals:

 Conserve limited water supplies

 Preserve drinking water source

 Produce more drinking water locally

 Protect coastal environment

 Manage the rising cost of potable water

The prelude to the program, which began in 1990, 

provided reclaimed water to local golf courses for 

irrigation. Initially, these users were not charged but 

later, a bulk rate was established, and a metered bulk 

rate was created for larger, interruptible customers. In 

1998, residential customers were added. Expansion 

strategies to retrofit areas of high potable water 

irrigation demand (500 gpd [1.9 m3

/d] or higher) were 

included in the Reclaimed Water Master Plan. Addition 

of residential projects and interconnection of the city’s 

three wastewater treatment plants provides a city-wide 

system serving over 3,000 metered accounts. 

Expansion of the Reclaimed Water 

System 

As part of the IWMS, Clearwater is expanding use of 

reverse osmosis (RO) technology and considering 

groundwater recharge (GWR), a form of indirect 

potable reuse (IPR). The GWR project includes 

construction of a water purification plant on the WRF 

site to supply 3 mgd (131 L/s) of highly treated water 

to recharge the Floridian Aquifer. Clearwater’s GWR 

project is now in pilot demonstration to optimize 

treatment and verify groundwater injection. Conditions 

are favorable to support GWR and additional 

withdrawal of groundwater for potable use in the 

future. GWR’s further benefits to the IMWS are 

projected as increasing permitted raw water supply, 

reducing bulk potable water purchases, reducing 

surface water discharges, and complying with total 

maximum daily load (TMDL) requirements and 

improving sustainability of the water resources.

Clearwater prides itself in its holistic view of water 

resources and technologies, both traditional and 

advanced, from wells to purchased water, 

conventional treatments to reverse osmosis, and 

reclaimed to potable reuse utilizing groundwater 

replenishment. Figure 1 illustrates the reduction in 

potable water demand over the past 2 decades due to 

conservation, education, and IWMS steps. Clearwater 

hopes to continue this trend in potable water use 

reduction. 

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Public engagement is critical as Clearwater 

implements its IWMS plan. A Community Partnership 

Program, launched in 2008, includes communication 

with leaders in business, civic groups, and other 

community stakeholders. Clearwater Public Utilities 

also chairs meetings with local municipalities’ utility 

leaders to discuss regulations, technologies, and other 

issues. 

Capacity and Type of Reuse 

Application 

Clearwater is built-out with minimal growth reflected by 

a flat water demand; Figure 2 shows the proportion of 

total potable demand eliminated by the use of 

reclaimed water. 

Project Funding

IWMS considers all water resources, and funding has 

been derived from rate payers and cooperative grants 

from the Southwest Florida Water Management 

District for infrastructure. From 1998 and projected 

through 2014, infrastructure costs are expected be 

$56.7 million. Wellfield expansion is $6 million, water 

treatment plant upgrades will be $46.7 million, and 

GWR will cost $29 million in capital improvement 

costs; all are slated for 50 percent grant funding.

Successes and Lessons Learned

Expansion of the reclaimed water system was based 

upon a cost-benefit ratio determined by weighing the 

cost to bring water to a certain geographic area 

compared to how much reclaimed water use could be 

expected. The more lushly landscaped neighborhoods 

ranked highly as well as coastal areas that had limited 

availability to fresh well water. As an incentive to 

connect and utilize the reclaimed water system, an 

availability charge was added to the utility bill of those 

properties that had opted to not connect to the 

reclaimed water system after completion of 

construction in their service area.

The city had to overcome a conflict in its ordinance, 

allowing private well owners and those irrigating from 

lakes and ponds to be exempt from the reclaimed 

water system. As the master plan moved inland from 

coastal neighborhood service areas, the number of 

well owners increased, and the payback period would 

have made some projects unsuccessful had the old 

Potable Water Consumption (gpcd)

Figure 1

Potable water consumption compared to District goals

Figure 2

Total water demand

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ordinance remained. A modification was made in 

response to the definition and implementation of the 

IWMS. The strategy outlines the hydrologic cycle and 

illustrates that well owners draw from either the

surficial or the Floridian aquifer, which is the same 

source that provides the city with its drinking water. 

Thus, if lower quality water is available for irrigation, it 

should be used first, allowing for best use of local 

drinking water resources.

References

City of Clearwater, 2007. Clearwater’s Integrated Water 

Management Strategy. Clearwater Public Utilities, 1650 N. 

Arcturas Ave., Bldg C, Clearwater, FL 33765.

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Assessing Contaminants of Emerging Concern (CECs) 

in Cooling Tower Drift

Authors: James P. Laurenson (HEAC) and Edward L. Carr (ICF International)

US-FL-Turkey Point

Background 

One of the primary industrial uses of reclaimed water 

is for recirculating evaporative wet cooling at electric 

power generation plants. With power generation 

expected to increase by about 18 percent in the United 

States and close to 70 percent globally between 2012 

to 2035 (EIA, 2011), the use of reclaimed water is 

expected to increase as fresh water supplies for 

cooling declines. 

Wet cooling at power plants typically results in the 

majority of cooling water leaving the plant via 

evaporation and aerosolization, often collectively 

known as drift. Drift, and any associated 

microorganisms, particulate matter (PM), or chemicals, 

can be inhaled by plant workers and the public. Other 

exposures might occur, such as through dermal 

contact or ingestion, but inhalation is expected to be 

the dominant exposure pathway. If exposure is greater 

than health-based thresholds, such as minimum 

infective doses for pathogens, PM standards, or 

minimal risk levels (MRLs) for chemicals, then risks 

could be considered significant and require mitigation 

through additional treatment or greater setback 

distances from the towers. While considerable 

attention in recent years has been given to the risks 

and mitigations related to microorganisms and PM 

levels in cooling tower drift at power plants, less 

attention has been given to contaminants of emerging 

concern (CECs), which are present in reclaimed water.

Capacity and Type of Reuse 

Application 

Florida Power & Light Company (FPL) and MiamiDade County (MDC) have been collaborating on an 

agreement to use reclaimed water as the primary 

supply for cooling for two new nuclear power units 

(Units 6 and 7) that are proposed for completion in 

2023 at the Turkey Point, Fla., facility (FPL, 2011). The 

reclaimed water also would be used for cooling an 

existing natural gas combined-cycle steam electric 

generating unit (Unit 5) that currently uses 

groundwater for cooling. Saltwater from Biscayne Bay 

would provide a backup cooling water supply for all 

three units. Waste heat would be dissipated by 

mechanical draft cooling towers. Draw-down 

(blowdown) wastewater from these towers would be 

discharged through the use of deep injection wells to 

the lower Floridan aquifer.

The use of reclaimed water at Units 5, 6, and 7 would 

be in addition to the current primary cooling system in 

place for existing units. The current system is a 

closed-loop set of approximately 5,900 ac (2,390 ha) 

of canals used for two natural gas/oil steam electric 

generating units (Units 1 and 2) and two existing 

nuclear units (Units 3 and 4). Because the canals are 

not lined, groundwater flow interacts with the 

hypersaline water in the canals, which has become a 

source of concern for this ecologically sensitive area 

within the Everglades watershed. Further, as part of a 

broader water resources management plan, MDC 

must increase its use of reclaimed water to more than 

170 mgd (7450 L/s) by 2025. Thus, an MDC resolution 

was passed that prevents FPL from applying for any 

water withdrawals from the Biscayne aquifer and 

encourages the use of reclaimed water.

As part of the Environmental Impact Statement (EIS) 

being developed by the Nuclear Regulatory 

Commission (NRC) for the application process, the 

impact of the reclaimed water on the environment and 

human health is being assessed (NRC, n.d.). One 

area of concern highlighted by public comments is 

inhalation of cooling tower drift by workers and the 

public (NRC, 2010).

Water Quality Standards and 

Treatment Technology 

Under the current plan, MDC would produce and 

deliver up to 90 mgd (3940 L/s), or 75 mgd (3290 L/s) 

on average, of reclaimed water to Turkey Point (FPS,

2011). The reclaimed water would be treated using 

high-level disinfection in accordance with Florida 

Department of Environmental Protection (FDEP) 

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regulations (Florida Administrative Code 62-610.668). 

Reclaimed water would be conveyed 9 mi (14 km) via 

pipelines from to the Turkey Point plant property where 

an onsite FPL treatment facility would further treat 

reclaimed water to reduce iron, magnesium, oil and 

grease, total suspended solids, nutrients, and silica to 

suitable concentrations for the circulating water 

system. 

For each of the two proposed nuclear power units, the 

cooling system would consist of three mechanical draft 

cooling towers and an open channel (flume) with a 

pump intake structure. Heated cooling water would 

flow through return piping to the mechanical draft 

cooling towers where heated cooling water would be 

circulated and heat would be transferred to the 

ambient air via evaporative cooling and conduction. 

After passing through the cooling tower, the cooled 

water would collect in the tower basin and be pumped 

back to the power unit, completing the closed cycle 

cooling water loop.

Makeup water from the FPL reclaimed water treatment 

facility would compensate for water losses during plant 

operation from drift and blowdown. Six circulating 

water cooling towers for Units 6 and 7, plus the 

existing Unit 5 towers, are estimated to result in 

evaporation and aerosol water losses of approximately 

50 mgd (2190 L/s) during normal plant operation, or 

approximately 67 percent of the makeup water.

Exposure Modeling 

An Environmental Report (ER), often used as a 

reference for developing an EIS, has been developed 

for Turkey Point (FPL, 2011). In the ER, the EPA 

CALPUFF and AERMOD dispersion models were 

used to evaluate cooling tower plume behavior. Five 

years (2001 through 2005) of hourly meteorological 

data from the Miami International Airport were used, 

along with physical and performance characteristics of 

the mechanical draft cooling towers. In the current 

version of the ER, CEC exposure has not been 

assessed, in large part because the additional 

treatment that FPL will apply to the reclaimed has yet 

to be fully designed. In the meantime, NRC is 

examining as a surrogate analysis the expected salt 

deposition described in the ER for the scenario 

whereby saltwater from Biscayne bay would be used 

as a backup cooling water source for Units 6 and 7. 

Figure 1 illustrates the predicted salt deposition near 

the plant when these units would be using salt water 

only. Non-volatile CECs thus also are likely to be 

deposited in a similar fashion, i.e., with the majority of 

deposition occurring in the immediate vicinity of the 

cooling towers. Screening level modeling of CECs 

exposure is being conducted by NRC and will become 

publicly available when the draft EIS is published in 

the near future. 

 

Figure 1

Surrogate for CECs deposition: predicted monthly 

salt deposition from use of only Biscayne Bay water 

for backup cooling (Photo credit: FPL, 2011)

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References

Energy Information Administration (EIA). 2011. International 

Energy Outlook 2011. Retrieved on April 2, 2012 from 

<http://www.eia.doe.gov/oiaf/ieo/electricity.html>.

Florida Power & Light (FPL). 2011. Turkey Point Plant, Units 

6 & 7, COL Application, Part 3, Environmental Report. 

Retrieved on March 25, 2012 from 

<http://pbadupws.nrc.gov/docs/ML1136/ML11362A171.html>.

U.S. Nuclear Regulatory Commission (NRC). n.d. Turkey 

Point, Units 6 and 7 Application. Retrieved on Sept. 5, 2012 

from <http://www.nrc.gov/reactors/new-reactors/col/turkeypoint.html>.

U.S. Nuclear Regulatory Commission (NRC). 2010. 

Environmental Impact Statement Scoping Process, 

Summary Report. Retrieved on March 25, 2012 from 

<http://pbadupws.nrc.gov/docs/ML1031/ML103130609.html>. 

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Sustainable Water Reclamation Using Constructed 

Wetlands: The Clayton County Water Authority 

Success Story

Authors: Veronica Jarrin, P.E. and Jim Bays, P.W.S (CH2M HILL); Jim Poff (Clayton

County Water Authority) 

US-GA-Clayton County

Project Background

The key water management challenges in Arizona are 

increasing demands for water, fully allocated existing 

water resources, and groundwater depletion. 

Groundwater depletion, or overdraft, is a result of 

excessive groundwater pumping and is problematic for 

numerous reasons, including its environmental 

impacts. Groundwater sustains rivers, streams, lakes, 

and wetlands providing the riparian habitat for wildlife. 

In the 19th century, wetlands, marshlands or cienegas, 

were common along rivers in Arizona; however, heavy 

pumping of groundwater beginning in the mid-20th 

century led to dewatered rivers and streams and loss 

of riparian ecosystems (Glennon, 2002). 

Just south of Atlanta, Georgia, the Clayton County 

Water Authority (CCWA) provides water, sewer, and 

stormwater services to more than 280,000 county 

residents and portions of adjacent counties. Since its 

creation in 1955, CCWA’s need for water supply and 

wastewater treatment has increased steadily with 

population growth, despite limitations on water supply 

and the assimilative capacity of the small local 

streams. 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. 

CCWA operated two LASs for almost 30 years as the 

County matured into a densely developed urbanized 

area. In response to the need for additional 

wastewater treatment capacity and as part of CCWA’s 

master planning process, numerous wastewater 

treatment alternatives were evaluated. With their 

consultant, CCWA reviewed existing treatment 

wetlands in Georgia (Inman et al. 2001) and identified 

constructed wetlands as the most reliable and 

sustainable option for both treatment and water supply 

augmentation (Inman et al., 2000).

CCWA constructed its first wetland reuse system in 

the southern end of the county. The Shoal Creek LAS 

was converted into a series of treatment wetlands 

(Panhandle Road Constructed Wetlands, Figure 1) 

and the existing wastewater treatment plant was 

replaced with an advanced, biological treatment plant 

(Inman et al., 2003). Following this success, CCWA 

began developing a larger wetlands complex on the 

E.L. Huie Jr. Site (Figure 2). Wetland construction was 

phased with portions of the existing LAS taken out of 

service and replaced with wetlands. 

Figure 1

The Panhandle Road Constructed Wetlands (Photo 

credit: Aerial Innovations of Georgia, Inc.)

Figure 2

The E.L. Huie Constructed Wetlands (Photo credit: 

Aerial Innovations of Georgia, Inc.)

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Capacity and Type of Reuse 

Application 

The wetlands consist of a series of interconnected, 

shallow ponds planted with native vegetation. The 

cells follow the site topography to allow water to flow 

passively through the wetlands by gravity. Even 

though a portion of the water in the wetlands is 

expected to infiltrate into the groundwater supply, 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; 

the detention time is less than a year under drought 

conditions (Thomas, 2005).

The Panhandle Road Constructed Wetlands consists 

of three multi-cell treatment trains, in parallel with a 

treatment capacity of 4.4 mgd (190 L/s) (CCWA, 

2011). The E.L. Huie Constructed Wetlands consist of 

nine multi-cell treatment trains built in four phases with 

a total treatment capacity of 17.4 mgd (760 L/s) 

(Table 1). 

Table 1 Characteristics of constructed wetland systems

System Date Sites 

Wet

Area

(ac)

Capacity

(mgd)

Total 

Capacity

(mgd)

Panhandle 

Road 

Constructed

Wetlands 

2002

North, 

Central, 

South

53 4.4 4.4

E.L. Huie 

Constructed 

Wetlands

2005 G 54 3.5

17.4 2006 D, E, F 40 2.6

2007 B, C, H, I 47 3.2

2010 A 123 8.1

Water Quality Standards 

Both wetland systems polish highly treated effluent 

from primary and secondary wastewater treatment 

facilities that include nutrient removal followed by 

disinfection. These treatment processes provide a 

multiple-barrier approach to water reclamation and 

enhance the removal of nutrients, microbial 

contaminants, and other trace organic compounds, 

providing a safe and secure supply of water. In 

addition, the constructed wetlands buffer the reservoirs 

in the unlikely event of a treatment plant upset.

A National Pollutant Discharge Elimination System 

(NPDES) permit was received for the constructed 

wetlands following an extensive review and approval 

process through the Georgia Department of Natural 

Resources (GAEPD, 2002). The first step in the 

process was for the Georgia Environmental Protection 

Division to set discharge limits by determining the 

allowable pollutant application to the wetlands. Both 

systems are required to comply with the waste load 

allocations established in their NPDES permit. These 

systems have proven to exceed their treatment 

expectations and effluent quality (Table 2). 

Table 2 NPDES discharge limits

Parameter

Panhandle Road 

Constructed 

Wetlands

E.L. Huie 

Constructed 

Wetlands

Limit 

(mg/L)

Actual3

(mg/L)

Limit 

(mg/L)

Actual3

(mg/L)

Flow (MGD) monitor 

only 1.35 monitor only 14.45

BOD5 10/151 1 10/151 3 

TSS 30/451 4 15/22.51 5 

NH3-N 

4/61 

(May-Oct.) 0.03 1.4/2.11 0.06 8/121

(Nov.-Apr.)

TP 2/31 0.59 0.62 0.24 1 Monthly/weekly averages 2 Annual average monitored only at the lake discharge 3 Average effluent data for 2011

With the completion of the largest phase of 

constructed wetlands in the fall of 2010, CCWA is able 

to recycle as much as 65 percent of daily water use 

into their existing reservoirs. This system augments 

CCWA’s water supply and reduces the need to 

withdraw water from the small streams that flow out of 

the county. During Georgia’s second worst drought on 

record, this system sustained raw water reserves at 77 

percent of capacity or greater. CCWA also has 

documented reductions in micro-constituents such as 

pharmaceuticals, hormones, and pesticides (CCWA, 

2011). 

Funding and Management Practices 

CCWA’s innovative water supply system and 

watershed protection program have required a 

significant commitment of resources. CCWA built the 

wetland system on land first purchased for the LAS in 

the late 1970s. Funding for the land purchase and 

construction of the LAS was primarily through the 

Federal Construction Grants program, under the Clean 

Water Act. Wetland cells were built using low-interest 

loans from State Revolving Funds, bonds, and rate 

payer revenue. Approximately four cents of every 

dollar collected for water and sewer service is set 

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aside for watershed protection (American Rivers, 

2009).

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. Rather than maintaining 

miles of irrigation pipes and numerous valves and 

pumps, routine maintenance consists primarily of 

checking hydraulics and vegetation management.

Successes and Lessons Learned

CCWA has been recognized as one of the most 

innovative and well-managed utilities in the 

southeastern United States. Most recently, the 

American Academy of Environmental Engineers 

awarded CCWA’s wetlands projects the “Excellence in 

Environmental Engineering” award for environmental 

stewardship. This approach to total water 

management has demonstrated that a sustainable 

water supply can be developed for a dense urban area 

where fluctuations in rainfall and water supply are 

common (Patwardhan, et. al, 2007). The wetlands 

treatment system and indirect reuse program have 

lowered CCWA’s need for additional reservoir storage 

and water withdrawals. 

The constructed wetlands have proven to require 

much less land, energy, and maintenance than the 

irrigation systems while sustainably using natural 

systems for water reclamation. Environmental benefits 

include CCWA’s use of the constructed wetlands 

facilities as an educational tool for customers to 

explain the importance of protecting water resources. 

CCWA was recognized by American Rivers as one of 

America’s “Water Smart” communities in 2009 and has 

received many awards for operations and innovation 

(CCWA and CH2M HILL, 2011).

This project is also an example of publicly accepted 

indirect potable reuse. CCWA has been polishing 

treated wastewater using natural treatment systems 

for more than 30 years and has actively communicated 

the wetlands reuse plan to the community. CCWA 

uses the constructed wetlands as an educational tool 

for customers to explain the importance of protecting 

water resources and hosts numerous community 

events. The wetlands also support the goals of land 

conservation. CCWA currently manages a wetlands 

education center that is open to the public to provide 

its customer base with information about how CCWA 

incorporates total water management in its day-to-day 

operations. 

References

American Rivers. 2009. Natural Security: How sustainable 

water strategies are preparing communities for a changing 

climate. Retrieved on Sept. 5, 2012 from

<http://www.americanrivers.org/library/reportspublications/natural-security-report-pubs.html>.

CCWA. 2011. Unpublished monitoring data 2009-2011.

CCWA and CH2M HILL. 2011. Clayton County Water 

Authority Sustainable Water Supply Project. Entry for 

Excellence in Environmental Engineering American 

Academy of Environmental Engineers.

CCWA. Water Reclamation. Retrieved on May 7, 2012 from 

<http://www.ccwa.us/water-reclamation>.

Georgia Environmental Protection Division. (GAEPD). 2002. 

Guidelines for constructed wetlands municipal wastewater 

treatment facilities.

Inman, B.L., M. Thomas, and J. Kirk. 2003: Construction and 

Startup of Treatment Wetlands on a Sloping Site.

Proceedings of the Water Environment Federation 

(WEFTEC). Session 31 through Session 40, pp. 391-391(1). 

Inman, B.L.; J. Kirk. S. Eakin, J. Bays, M. Thomas, L. 

Philpot, Lonnie; B. Knight, R. Clarke. 2001. Review of 

Georgia's Constructed Treatment Wetlands and Their 

Performance. Proceedings of WEFTEC: Session 11 through 

Session 20, pp. 621-632(12). 

Inman, Brad L.; M. Thomas, R.L. Knight. 2000. Maximizing 

Treatment Capacity with Natural Systems. Proceedings of 

WEFTEC: Session 11 through Session 20, pp. 283-301(19). 

Patwardhan, A.S., D. Baughman, A. Tyagi, and J. Thorpe. 

2007. Developing and Implementing a TWM Strategy – 

Approaches and Examples. Journal AWWA, 99, (2), 64-75.

Thomas, M. 2005. Sustainable water resources 

management by Georgia utilities: Clayton County Water 

Authority. Proceedings of the 2005 Georgia Water 

Resources Conference, Athens, Georgia. April 25-27, 2005. 

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2012 Guidelines for Water Reuse

On the Front Lines of a Water War, Reclaimed Water Plays 

a Big Role in Forsyth County, Georgia

Author: Daniel E. Johnson, P.E. (CDM Smith)

US-GA-Forsyth County

Project Background or Rationale 

Forsyth County, Ga., lies on the west bank of one of 

the most controversial bodies of water in the country—

Lake Lanier. Since 1989, Lake Lanier has ridden the 

front lines of the battle between Georgia, Alabama, 

and Florida dubbed the “Water Wars.” Lake Lanier is 

the uppermost of four major water bodies along the 

Chattahoochee River system that runs from the North 

Georgia Mountains, through Atlanta and Columbus, 

Ga., the Florida panhandle, and eventually discharging 

to the Gulf of Mexico. Given that over three million 

people in Atlanta currently rely on Lake Lanier as a 

source for drinking water, and the fact that this number 

is expected to grow by 55 percent by 2035, 

downstream users are fighting to maintain flows in the 

rivers. The U.S. Army Corps of Engineers (USACE), 

who controls the lake system, has temporarily placed a 

cap on new water withdrawals from Lake Lanier until 

the legal fight has run its course. 

The Forsyth County Department of Water and Sewer 

currently serves over 46,000 water customers and 

completely relies on raw or purchased water from 

neighboring utilities. The county has repeatedly 

requested a USACE surface water withdrawal from 

Lake Lanier and been denied each time. Throughout 

the 2000’s Forsyth County has maintained its status as 

one of the top 5 fastest growing counties in the nation 

having grown from a population of 98,367 in 2000 to 

175,511 in 2010. In order to meet the growing water 

demands for an ever increasing population, the county 

evaluated alternatives for water supply including 

increased water conservation and reuse.

In the late 1990’s Forsyth County realized it needed a 

centralized wastewater treatment plant to support 

rapid development and the projected growth. During 

the planning phase, the county understood the value 

that reclaimed water could play with respect to 

minimizing its potable water demand. The county 

embarked on design and construction of one of the 

first membrane facilities in Georgia. In addition to the 

new facility, a reclaimed water pipeline leading to a 

land application system was constructed. In 2004, 

Forsyth County completed construction of the Fowler 

Water Reclamation Facility (WRF) and reclaimed 

water pipeline. Soon after startup, the county 

implemented a reuse program that included 

construction standards, public information, and 

applications and end user agreements for connecting 

to the system. Today, Forsyth County serves 16 major 

end users with reclaimed water including several 

parks, schools, shopping centers, golf courses, a bus 

wash facility, neighborhood green space, and a rock 

quarry. 

In 2011, Forsyth County purchased the James Creek 

WRF whose reuse quality effluent is also discharged 

into the common 20-in (50-cm) distribution main. With 

connection of the James Creek WRF an additional 

1 mgd (44 L/s) of capacity was added to the reclaimed 

water system.

Reclaimed Water Use and Climate 

Reclaimed water has been widely accepted within the 

community with little to no opposition. Local residents 

are intimately familiar with the value of water, having 

suffered through two severe droughts during the 

2000’s when the state ordered a ban on all outdoor 

water use. Generally, the metro Atlanta area receives 

over 50 in (127 cm) of rainfall per year. With such a 

high average rainfall, most communities are adorned 

with lush hydrophilic landscapes. When the outdoor 

watering bans were implemented, the interest in reuse 

increased. 

During the summer months, Forsyth County distributes 

approximately 700,000 gallons (2,650 m3

) of reclaimed 

water per day, but this is reduced to less than 20,000 

gallons (76 m3

) per day during the winter months. Up 

to 100 percent of the reclaimed water is distributed to 

end users during summer month peak demands, thus 

Forsyth County is limited in the number of end users 

that it can serve until it receives additional wastewater 

from new development.

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Capacity and Type of Reuse 

Application 

The Fowler WRF current capacity to produce 

reclaimed water is 1.25 mgd (55 L/s) with a permit to 

upgrade the facility to 2.50 mgd (110 L/s) with the 

installation of additional membranes. The reclaimed 

distribution system pumps treated effluent from a 6 

million gallon (22,700 m3

) ground storage tank through 

the 20-in (50-cm) pipeline to its end at a land 

application field where any unused reclaimed water is 

discharged. The 16 end user connections are 

scattered along the 11 mile pipeline route. The system 

is designed to maintain a minimum pressure of 20 psi 

(140 kPa) at the high point of the pipeline.

Reclaimed water in Forsyth County is generally 

supplied for irrigation however the school system 

utilizes reclaimed water for bus washing. Additionally, 

hydrants are provided in multiple locations for 

contractor use in dust control, paving, hydro seeding, 

etc. 

Water Quality Standards and 

Treatment Technology 

In Georgia, reclaimed water must undergo secondary 

treatment (30 mg/L BOD5 and 30 mg/L TSS) followed 

by coagulation, filtration and disinfection, or equivalent 

treatment. The reclaimed water treatment criteria are 

summarized in Table 1. 

Table 1 Georgia reclaimed water treatment criteria

Parameter Criteria

BOD5 ≤ 5 mg/L

TSS ≤ 5 mg/L

Fecal Coliform

≤ 23 cfu/100mL

monthly geometric mean, 

100 cfu/100mL maximum per sample

pH 6-9 standard units

Turbidity ≤ 2 NTU

The Fowler WRF utilizes hollow fiber membrane 

filtration and UV disinfection to achieve reuse quality 

effluent. The James Creek WRF utilizes flat plate 

membrane filtration and UV disinfection.

Project Funding and Management 

Practices 

Forsyth County constructed the Fowler WRF and 20-

inch reuse pipeline with revenue bonds. The County 

sells reclaimed water for $1.75/1,000 gallons 

($0.45/m3

), equivalent to half the potable rate, which it 

uses to repay its debt in conjunction with its water and 

sewer fees. Forsyth County has a designated 

representative from the water and sewer department in 

charge of managing end user accounts, providing 

public education to end users, overseeing system 

operations and performing cross-connection testing. 

Institutional/Cultural Considerations 

The public education program includes an in-person 

learning session after which the end user is required to 

satisfactorily pass a 20-question application test prior 

to connecting to the system. Open house style public 

information sessions have not been needed as the 

public is generally in favor of the reuse program. 

Successes and Lessons Learned

The key factors for success for this project included 

the early considerations for sufficient reclaimed water 

storage to handle peak demands and the installation of 

infrastructure sized for the future growth of the system. 

A few lessons have been learned from the 

management of a reclaimed water system. First, when 

connecting any new user to the system, a crossconnection test should always be performed by the 

utility. Cross-connection tests should also be 

performed by the end user on an annual basis. 

Second, consideration should be made to maintain a 

minimum pressure in the distribution main to meet 

pressure requirements of an irrigation system. 

Otherwise, end users will require a booster pump 

station to increase system pressures. 

References

Georgia Environmental Protection Division. Guidelines for 

Water Reclamation and Urban Water Reuse. 2002.

Atlanta Regional Commission website. 2011. Accessed on 

Sept. 5, 2012 at <http://www.atlantaregional.com/>.

Georgia Water Council, Georgia Comprehensive State-wide 

Water Management Plan, 2008.

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2012 Guidelines for Water Reuse

Recovery and Reuse of 

Beverage Process Water

Authors: Dnyanesh V. Darshane, PhD, MBA; Jocelyn L. Gadson, PMP; Chester J. Wojna; 

Joel A. Rosenfield, Henry Chin, PhD; Paul Bowen, PhD (The Coca-Cola Company)

US-GA-Coca Cola

Project Background or Rationale 

In the face of increased water scarcity, water costs, 

growth projections, and other drivers, Coca-Cola 

bottling plants sought to further improve their water 

use efficiency. This led to the pursuit of a scientifically 

rigorous, widely applicable water recovery and reuse 

approach that could be used by virtually any of the 

nearly 900 bottling plants in the Coca-Cola system.

Capacity and Type of Reuse 

Application 

Water is typically recycled for applications such as 

floor washing, landscape irrigation, etc. Though used 

for non-product activities and applications, the quality 

of this highly purified water enables its use for a higher 

degree of purpose, such as indirect potable reuse. 

Water Quality Standards and 

Treatment Technology 

The framework for this project was based on the water 

safety plan approach consisting of: source vulnerability 

assessment, source water protection plan, system 

design, operational monitoring, and management 

plans. 

The system design takes beverage process 

wastewater and further purifies it to high standards for 

use in non-product applications. This process uses a 

combination of technologies: chemical treatment, 

biological treatment in a membrane bioreactor, 

ultrafiltration (UF), reverse osmosis (RO), ozonation, 

and ultraviolet (UV) disinfection. These technologies 

are described below. 

 Secondary biological treatment. 

 UF uses a pressure-driven barrier to remove 

suspended solids and pathogens. 

 RO forces water through membranes under 

high pressure, removing some dissolved 

chemicals and other compounds to produce 

water with very high purity and low total 

dissolved solids. 

 Ozonation destroys microorganisms and 

oxidizes organic materials.

 Medium pressure UV light disinfects water by 

rendering microorganisms inactive.

 Mixed oxidant disinfection.

 Chlorination at several points, as appropriate for 

disinfection and oxidation.

The choice of treatment technologies would be 

dependent upon the characteristics of the beverage 

waste stream and the planned point-of-use of the 

water. Some of these technologies effectively remove 

contaminants, such as heavy metals, while others 

disinfect. Further, the system employed significant 

continuous monitoring, automation, and controls. 

Two water recovery options were assessed: inprocess treatment and process waste water treatment. 

The in-process reuse option involves the 

manufacturing process wastewater stream being 

treated and reused in the same manufacturing function 

before it reaches the wastewater treatment system, 

reducing the fresh water requirements for the 

manufacturing function. The wastewater stream from a 

given manufacturing process is sent directly to 

advanced treatment, bypassing the plant-wide 

wastewater treatment process. After passing through 

appropriate treatment the process waste stream is 

recycled back into the process from which it originated. 

The quality of the water meets the water standards 

required for the process.

In the process wastewater treatment configuration, the 

wastewater streams from all manufacturing processes 

are sent to the existing wastewater treatment system. 

A portion of the treated effluent is then sent through 

required advanced treatment steps and recycled back 

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to one or more manufacturing 

processes. This option provides the 

greatest quantity of reuse water 

because it aggregates manufacturing 

waste streams (but not sanitary or 

cafeteria waste streams) from the 

entire plant. Figure 1 shows both 

options for in-process reuse and 

advanced process wastewater 

treatment. 

Project Funding and 

Management Practices

On-going sustainability activities are 

imperative to our business and 

community. The Coca-Cola Company 

is implementing a holistic approach to 

water stewardship, recognizing that water must be 

considered in the greater context of political, societal 

and ecological dynamics (TCCC, 2012). Industrysponsored guidelines for the implementation of water 

reuse in the beverage industry are currently in 

development (ILSI, 2012). Future work will include 

measures to reduce the overall impact of energy 

usage. By implementing this recycle and reuse model, 

The Coca-Cola Company will continue to reduce its 

water usage. 

Successes and Lessons Learned

The highly purified water from this commercial trial 

consistently met internal and external regulatory 

standards and specifications. Samples were analyzed 

throughout the process treatment train to assess the 

efficiency and capabilities of each step of the 

treatment process. The quality of the final effluent 

water was crucial to the success of the commercial 

trial. 

Samples at each intermediate process as well as the 

final effluent were tested extensively by internal and 

external laboratories. Analyses by the third party labs 

were conducted for 126 parameters, including: 

inorganics, synthetic organics, “semivolatile organics,” 

volatile organics, disinfection related chemicals 

(including trihalomethanes), pesticides, and microbial 

analysis for E. coli. 

The analytical results of final treated water were 

compared to internal standards, WHO guidelines for 

drinking water, EPA drinking water regulations, and 

applicable local regulations per plant locations. 

Meeting drinking water quality specifications was 

considered to be essential for much of the recovered 

water even though the water was only reused for nonproduct activities. The results (Table 1) comply with all 

parametric limits: 1) chemical, 2) microbial, and 3) 

operational. The analysis indicated all results were 

below specification limits or non-detected. 

Table 1 Summary of six months of process performance 

indicators (sample frequency every 4 hours)

Parameter

Internal

Specification Average

Standard 

Deviation

Alkalinity 85 mg/mL as 

CaCO3

27.72 3.02

pH 4.9 minimum 6.32 0.68

TDS 500 mg/l 34.91 4.63

Turbidity 0.3 NTU 0.11 0.02

TOC 0.5 mg/L 0.17 0.03

Color Sensory Acceptable

Odor Sensory Acceptable

In addition to microbial analysis of the renewed water, 

the plant was required to assess the microbial levels at 

the start and end of each process step. The plant 

analyzed for total plate count (TPC) and coliforms; an 

external laboratory performed the analysis for E. coli. 

Neither coliforms, nor E. coli were detected in any of 

the samples. The results (Table 1) of our 6 months of 

monitoring process performance indicators every four 

hours demonstrate the effective operation of each 

process step of the wastewater recovery and reuse 

system. 

The commercial trial conducted in this study 

successfully demonstrated the capability to recover 

and treat process wastewater to the highest quality 

Figure 1

Water recovery schematic of The Coca-Cola Company

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2012 Guidelines for Water Reuse

standard using a multi-barrier approach with advanced 

treatment technologies.

The treatment system was operationally stable and 

consistently produced highly purified water that met all 

physical, chemical, and microbial specifications. This 

highly purified water meets the stringent drinking water 

guidelines and requirements of World Health 

Organization, the European Union, EPA, the CocaCola Company, as well as local regulatory 

requirements for each plant location.

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2012 Guidelines for Water Reuse

Reclaimed Water Use in Hawaii

Author: Elson C. Gushiken (ITC Water Management, Inc.)

US-HI-Reuse

Project Background or Rationale 

Hawaii has been established a reclaimed water 

program over the past two decades. The program 

varies by county, based on specific drivers for water 

reuse. Hawaii has six major islands (Hawaii, Maui, 

Oahu, Kauai, Molokai and Lanai) and two smaller 

islands (Niihau and Kahoolawe) totaling 6,463 mi2 

(16,740 km2) that comprise an island chain stretching 

northwest to southeast over a zone 430 mi (706 km) 

long. Each 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 the U.S. Army Corps 

of Engineers, has determined that a water 

conservation plan for Hawaii should be established. 

Reclaimed water is anticipated to be a significant 

contributing component of the plan’s policy and 

program development.

Regulatory Requirements 

Explosive growth in Japanese visitors to Hawaii in the 

1970’s and 1980’s spurred a corresponding increase 

in resort and golf course developments. The search for 

nonpotable water resources for resort golf course and 

landscape irrigation led to many inquiries to the Hawaii 

State Department of Health about the availability of 

reclaimed water for reuse. Thus, in the early 1990’s 

the Hawaii State Department of Health deemed the 

state’s existing wastewater regulations deficient in 

providing proper guidance for the treatment and 

beneficial use of reclaimed water, which led to the 

development of Hawaii’s first reuse guidelines. The 

Hawaii “Guidelines for the Treatment and Use of 

Reclaimed Water” were issued in November 1993 and 

were adopted into Hawaii Administrative Rules Title 

11, Chapter 62, Wastewater Systems. The guidelines 

were updated in May 2002 and re-titled the 

“Guidelines for the Treatment and Use of Recycled 

Water.” The guidelines define three classes of 

recycled water as R-1, R-2, and R-3 water.

R-1 Water is the highest quality recycled water. It is 

treated effluent that has undergone filtration and 

disinfection and can be utilized for spray irrigation 

without restrictions on use. 

R-2 Water is disinfected secondary (biologically) 

treated effluent. Its uses are subjected to more 

restrictions and controls.

R-3 Water is the lowest quality recycled water. It is 

undisinfected secondary treated effluent whose uses 

are severely limited.

Water Reuse Program 

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.

County of Maui (Islands of Maui, Molokai 

and Lanai)

The county of Maui consists of three islands; Maui, 

Molokai, and Lanai and are located to the northwest of 

the Big Island of Hawaii. The county’s water reuse 

efforts are led by its municipal wastewater agency, the 

Wastewater Reclamation Division. The first feasibility 

studies were conducted in 1990 and led to a long-term 

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program to reuse millions of gallons of reclaimed 

water, previously disposed into injection wells. The 

program began with passing of a mandatory reclaimed 

water ordinance. In 1996, the county then adopted its 

own County of Maui Rules for Reclaimed Water 

Service incorporating the State of Hawaii’s Guidelines 

for the Treatment and Use of Recycled Water, the 

State of Hawaii’s Water System Standards and 

Chapter 11-62 of the Hawaii Administrative Rules. To 

date, Maui County provides reclaimed water for 

irrigation, toilet flushing at the National Park Service, 

and dust control. Currently, landscape irrigation using 

reclaimed water occurs at five golf courses, five

community parks, the elementary school, intermediate 

school, public library, fire station and fire system, 

community center, four multi-family housing units, 

highway shoulders and medians, a shopping center, 

landscape at commercial buildings, seed corn crop 

irrigation, green waste composting/vermiculture, and 

constructed wetlands.

County of Honolulu (Island of Oahu)

Honolulu is located on the Island of Oahu northwest of 

Maui County’s Islands. The municipal drinking water 

agency on the Island of Oahu is the Honolulu Board of 

Water Supply (BWS). The Honolulu BWS expects to 

meet Oahu’s water demands through 2030 through an 

integrated strategy of combining existing water system 

capacities, planned infrastructure improvements and 

watershed protection strategies. As part of Oahu’s 

integrated water resources plan, the Honolulu BWS 

has taken the lead on water reuse efforts on the 

island. With a heavy military presence on Oahu, the 

various military branches, in collaboration with the 

state of Hawaii and the Honolulu BWS, are 

implementing energy and water conservation 

programs. In 2000, the Honolulu BWS purchased the 

newly completed Honouliuli Water Recycling Facility 

from U.S. Filter. The facility produced 12 mgd (526 

L/s) of R-1 water, 10 mgd (438 L/s) designated for 

irrigation and 2 mgd (88 L/s) for reverse osmosis (RO) 

water. 

Honolulu BWS incorporated into its rules and 

regulations that if a suitable nonpotable water supply is 

available, the department shall require the use of 

nonpotable (reclaimed) water for irrigation of large 

landscaped areas such as golf courses, parks, 

schools, cemeteries, and highways.

In 2004, the U.S. Army awarded a 50-year 

privatization contract for the upgrading the Schofield 

Wastewater Treatment Plant in order to produce R-1 

water for irrigating the Schofield Army 

Barracks/Wheeler Army Air Field golf course, athletic 

fields, parade grounds and parks.

R-1 water produced at the Honouliuli Water Recycling 

Facility currently provides reclaimed water to 

numerous sites and is continually adding additional 

users. Existing users include nine golf courses, four

community parks, municipal and state building 

facilities, public library, police station, highway 

shoulders and medians, four multi-family housing 

units, private college campus, shopping center, sports 

field, commercial landscaping, agriculture, feed for RO 

water for steam generation at refinery and energy 

facilities, and dust control at construction sites. 

County of Hawaii (Island of Hawaii)

The county of Hawaii, which encompasses the Big 

Island (Island of Hawaii), does not currently have a 

water reuse program. All municipal wastewater 

facilities produce R-2 quality water, for permitted 

infiltration basin and permitted ocean outfall disposal. 

The use of reclaimed water on the island of Hawaii is 

primarily driven by private resort developments with 

their own wastewater treatment plants that produce R2 water. Most reclaimed water is blended with brackish 

water sources and used for irrigation. The blended 

water is used for irrigation at six private golf courses, 

pasture, airport landscaping, plant nursery, sod farm, 

and composting.

County of Kauai (Island of Kauai)

The County of Kauai is located on the Island of Kauai, 

in the northwestern most island of the state. Kauai has 

four municipal wastewater treatment facilities 

(WWTFs). Although water reuse is a responsibility of 

the county of Kauai’s Division of Wastewater 

Management under its Wastewater Treatment 

Facilities Program, the county does not have a stated 

reclaimed water program. Kauai’s abundant surface 

water resources provide nonpotable irrigation water for 

many golf courses and agricultural operations. As 

such, historically, reclaimed water use on Kauai, 

whether derived from municipal or private WWTFs, 

was considered more of a convenient effluent disposal 

option rather than a water supply resource.

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In 2011, the county’s Lihue WWTF was upgraded to 

an R-1 facility through funding from an adjacent private 

resort development seeking higher quality R-1 

irrigation water for golf course expansion and 

subdivision development. In addition, the county’s 

Waimea WWTF located on the dryer, west side of the 

island is being upgraded to an R-1 facility to provide 

irrigation water for parks, school fields and a future golf 

course.

Project Funding and Management 

Practices 

Funding for the county of Maui’s R-1 water reuse 

program is through a combination of recycled water 

fees and sewer user fees. Sewer user fees pay for 

approximately 75 percent of program costs including 

debt service and operation and maintenance 

expenses. Fees for reclaimed water service are set in 

Maui County’s annual budget. Reclaimed water fees 

are divided into three consumer classes: major 

agriculture, agriculture, and all others.

Most of the funding of the Kihei WWRF R-1 water 

production and distribution infrastructure was obtained 

through the State Revolving Fund program general 

obligation bonds.

Engineering design and physical improvements to 

upgrade the county of Kauai’s Lihue Wastewater 

Treatment Facility from an R-2 to R-1 facility was 

borne by the owners of the existing adjacent Kauai 

Lagoons Golf Club resort development. The 

developers needed the higher quality R-1 water to 

spray irrigate the common landscaped areas of 

proposed private home developments within the resort 

property and the newly redesigned golf course. 

Successes and Lessons Learned

Public acceptance of reclaimed water throughout 

Hawaii over 20 years has been very positive. This 

success can be largely attributed to the understanding 

primarily by state and municipal officials, private 

consultants and developers of lessons learned 

gleaned from the early challenges and hurdles faced 

by water reuse advocates in other parts of the country, 

especially California. Early involvement of reclaimed 

water stakeholders and ongoing public education has 

been key to Hawaii’s successful reclaimed water 

program. 

References

Hawaii State Department of Health Wastewater Branch, 

Guidelines for the Treatment and Use of Recycled Water, 

May 15, 2002. Retrieved on Sept. 5, 2012 from

<http://hawaii.gov/wastewater/pdf/reuse-final.pdf>.

Honolulu Board of Water Supply, Oahu Water Management 

Plan Overview, May 31, 2006. Retrieved on Sept. 5, 2012 

from

<http://www.boardofwatersupply.com/files/03_Overview.pdf>. 

South Maui R-1 Recycled Water Verification Study, 

Department of Environmental Management, Wastewater 

Reclamation Division and Department of Water Supply, 

Water Resources Planning Division, December 2009.

Retrieved on Sept. 5, 2012 from

<http://www.co.maui.hi.us/documents/11/28/456/South%20

Maui%20R1%20Recycled%20Water%20Verification%20Study.pdf>.

Central Maui R-1 Recycled Water Verification Study, 

Department of Environmental Management, Wastewater 

Reclamation Division and Department of Water Supply, 

Water Resources Planning Division, December 2010.

<http://www.co.maui.hi.us/documents/11/28/456/Central%20

Maui%20Recycled%20Water%20Verification%20Study.pdf>.

The Limtiaco Consulting Group, 2005. 2004 Hawaii Water 

Reuse Survey and Report Final.

Hawaii QuickFacts for the US Census Bureau. Retrieved 

Sept. 5, 2012 from 

<http://quickfacts.census.gov/qfd/states/15000.html>.

State of Hawaii Department of Business, Economic 

Development and Tourism, Visitor Statistics, 2010 Annual 

Visitor Spreadsheet. Last Accessed January 2012. 

<http://hawaii.gov/dbedt/info/visitor-stats/visitor-research/>.

University of Hawaii Department of Geology, Atlas of Hawaii, 

Second Edition, 1983. University of Hawaii Press, Honolulu. 

Western Regional Climate Center, Desert Research 

Institute, National Oceanic and Atmospheric Administration 

Narrative Summaries, Tables and Maps for Each State with 

Overview of State Climatologist Programs, Third Edition, 

Volume 1: Alabama-New Mexico, 1985 - Gale Research 

Company, Climate of Hawaii. Accessed on January 2012

from <http://www.wrcc.dri.edu/narratives/HAWAII.htm>. 

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Sustainability and LEED Certification as Drivers for Reuse:

Toilet Flushing at the Fay School

Author: Mark Elbag (Town of Holden)

US-MA-Southborough

Project Background or Rationale 

The Fay School is a private day and boarding school 

for elementary and middle school students in 

Southborough, Massachusetts (Figure 1). It consists 

of 22 buildings that facilitate 552 students and faculty, 

30 percent of which reside on campus as part of the 

boarding school. In 2011, the school was producing 

7,900 gpd (30 m3

/d) of wastewater and is projecting a 

20 percent growth of students and faculty resulting in a 

future wastewater production of 10,500 gpd (40 m3

/d). 

The most significant opportunities for water reuse at 

the Fay School were identified. Project drivers for the 

implementation of a water reuse program included 

cost savings from reduced water use, environmental 

awareness and sustainability teaching opportunities, 

and the potential for LEED Gold Certification.

Capacity and Type of Reuse 

Application 

This project was part of a campus expansion that 

included LEED certification of buildings and use of 

“green” technologies and construction practices. The 

consultant worked closely with the school and the 

Massachusetts Department of Environmental 

Protection (DEP) on the water reuse system 

permitting, effluent testing and quality requirements. 

Construction of a 26,500 gpd (100 m3

/d) membrane 

bioreactor wastewater treatment facility was completed 

in 2009. A portion of the reclaimed water is to be 

reused for toilet flushing in five new dormitory facilities 

and a new maintenance building. Based on fixture 

count, the water reuse demand was estimated at 40 

gpm (262 m3/d). As a school facility, the Fay School 

experiences significant fluctuations in wastewater flow 

rate over the course of a day and throughout the year. 

Careful planning was required so that adequate pretreatment and post-treatment storage capacity was 

provided and the treatment capabilities of the 

equipment at the facility would be able to address 

these fluctuations.

Water Quality Standards and 

Treatment Technology 

The system is designed to produce effluent total 

nitrogen concentrations below 10 mg/L. The 

membranes are designed to produce filtered effluent 

with less than 2 NTU, as required for reuse in the state 

of Massachusetts. Ultraviolet disinfection is designed 

to meet reuse limits of less than 14 cfu/100 mL as a 

monthly median fecal coliform concentration.

Project Funding and Management 

Practices 

The project was privately funded through Fay School 

student tuition. The additional capital cost for 

wastewater treatment attributable to reuse was 

$75,000. The cost of potable water at the Fay School 

is approximately $6/1000 gallons ($1.59/m3

). A 

financial analysis was conducted that showed when 

water demand is greater than 5,000 gpd (19 m3

/d), the 

cost of reclaimed water is less than potable water 

based on a 20-year lifecycle analysis (Figure 2). 

Figure 1

The Fay School, Southborough, Massachusetts

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Successes and Lessons Learned

Fay School Achieved LEED Gold Certification from the 

U.S. Green Building Commission for the Phase 1 

Project. 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 out of the Fay Schools interest 

in sustainable design principles which is a benefit to 

the education of students and the importance of water 

reuse. This concept is an excellent example of how to 

integrate and promote water reuse into an educational 

institution. 

References

Water Reuse Foundation (WRF). 2005. An Economic 

Framework for Evaluating the Benefits and Cost of Reuse 

Water. September 2005.

Figure 2

Cost of water per 1,000 gallons

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Decentralized Wastewater Treatment and Reclamation for 

an Industrial Facility, EMC Corporation Inc., Hopkinton, 

Massachusetts

Author: Mike Wilson, P.E. (CH2M Hill)

US-MA-Hopkinton

Project Background or Rationale 

EMC manufacturers electronic data storage systems 

and has a one million square foot campus located in 

Hopkinton, Mass. The corporation had an interest in 

LEED certification and green design principles for 

engineering and production facilities, which are located 

in watersheds of the Charles, Concord, and 

Blackstone Rivers. 

EMC is the town’s largest potable water user. Water 

supply is groundwater from wells in the town, and a 

neighboring town. During summer peak seasonal 

demand, Hopkinton can experience water shortages 

and in these periods has banned outdoor water use. 

EMC went beyond basic environmental compliance 

and built a decentralized wastewater treatment plant 

and wastewater reclamation facility which produces 

reclaimed water for toilet flushing and irrigation. 

Construction of the EMC Corporate Headquarters 

achieved a LEED EB certification for use of 

sustainable design best management practices and 

energy reductions. The project reduced potable water 

demand on a seasonally limited aquifer and provided 

needed groundwater recharge. 

Capacity and Type of Reuse 

Application 

The plant includes a sequencing batch reactor 

activated sludge process followed by cloth media 

filtration and UV disinfection before storage in a 

finished water tank. The facility went into service in 

2000 and has a capacity of approximately 83,000 gpd 

(314 m3

/d) and has the ability to reclaim 100 percent of 

its wastewater. Approximately 25 percent is used for 

toilet flushing and the remaining 75 percent is used for 

groundwater recharge and irrigation. Approximately 4 

million gallons (18,000 m3

) of water is reclaimed per 

year. 

Water Quality Standards and 

Treatment Technology 

The reclaimed water quality exceeds the requirements 

for reuse in Massachusetts. A summary of the typical 

influent wastewater characteristics and reclaimed 

water quality is provided in Table 1. 

Table 1 Typical water quality

Parameter

Raw 

Wastewater Effluent

BOD (mg/L) 221 < 2

TSS (mg/L) 286 < 2

TN (mg/L) 64 < 2

Turbidity (NTU) < 1

Project Funding and Management 

Practices 

The project was constructed with private funds from 

EMC Corporation; the water reclamation facility

decreases the potable water demand by approximately 

25 percent. Approximately $500,000 per year in cost 

savings is realized due to reduced water and sewer 

fees from the town. The plant’s annual operating cost 

is approximately $400,000. 

Successes and Lessons Learned

Monitoring of toilet flush valves, flows, and system 

demand is important because a sticking toilet flush 

valve can significantly impact the use of reclaimed 

water by rapidly depleting the finished water storage. 

Installation of flow limiters and low flush toilets has

reduced the impacts of this issue. 

References

Sauvageau, Paul. “EMC’s Visionary Plan, Embracing Water 

Sustainability.” Presentation to the Environmental Business 

Council New England, February 24, 2010. 

Metropolitan Area Planning Council, “Once is Not Enough – 

A Guide to Water Reuse in Massachusetts.” The 495 

Metrowest Corridor Partnership, November 2005.

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Sustainability and Potable Water Savings as Drivers for 

Reuse: Toilet Flushing at Gillette Stadium

Author: Mike Wilson, P.E. (CH2M HILL) 

US-MA-Gillette Stadium

Project Background or Rationale 

The New England Patriots management determined 

that the new Gillette Stadium (Figure 1) was projected 

to increase potable water demand by as much as 

600,000 gpd (2,300 m3

/d) during home games, largely 

due to toilet flushing. Increased water demand would 

stress water supply wells and storage tank system, 

and the corresponding increase in wastewater 

produced at the stadium would be greater than the 

capacity of Foxborough’s wastewater treatment plant. 

To reduce impacts of the projected increases in 

potable water use and wastewater demand, the 

Patriots worked with the town and Massachusetts 

Department of Environmental Protection (DEP) to 

construct a new water reclamation facility (WRF) that 

would reduce demand for potable water. The benefits 

of the new system were reduced potable water 

demands and recharge of the groundwater. The 

system was put into operation in 2002 when the new 

stadium opened. 

Capacity and Type of Reuse 

Application 

A 0.25 mgd (11 L/s) wastewater reclamation plant that 

is expandable to 1.3 mgd (57 L/s) was constructed, 

along with a subsurface disposal system for a portion 

of the reclaimed water. The plant includes a 

membrane bioreactor (MBR), and ozone and UV 

disinfection (American Water, n.d.). Reclaimed water 

is pumped to a 500,000 gallon (1900 m3

) elevated 

storage tank or to the subsurface disposal system. A 

new purple pipe (to indicate reclaimed water) system 

was constructed because it was determined to be 

favorable to retrofitting existing piping. On average 

about 60 percent of the wastewater is reused for toilet 

flushing at the stadium. The remaining reclaimed water 

is pumped to the subsurface disposal system where it 

recharges the groundwater. Toilet flushing demands 

can vary dramatically and to accommodate these 

demands, the new reclaimed water supply system 

includes a one million gallon elevated storage tank at 

the stadium, and several thousand feet of new water 

distribution mains. 

Water Quality Standards and 

Treatment Technology 

The complete system required integration of a 

groundwater discharge permit with water reuse 

requirements because the system included infiltration 

basins under the parking area. The project included 

design of an on-site infiltration field and “daylighting” of 

the Neponset River from an underground culvert to a 

meandering open channel. When the system was 

designed, the Massachusetts DEP did not have formal 

water reuse regulations; there were however, 

guidelines and precedents had been established 

through implementation of several other previous 

water reuse projects. The plant is meeting all of its 

permit limits and water quality objectives which include 

biochemical oxygen demand, total suspended solids, 

total nitrogen, and fecal coliform. The facility reuses 

approximately 10 million gallons (38,000 m3

) of 

reclaimed wastewater per year.

Project Funding and Management 

Practices 

The project was constructed with private and municipal 

funds and the reuse system was constructed on a 

Figure 1

Gillette Stadium, Foxborough, Mass. (Photo credit: 

Kathleen Esposito)

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design-build basis (AW, n.d.). The complete water and 

wastewater system project had an overall capital 

construction cost of $13 million. 

Successes and Lessons Learned

The town owns the potable water system and the WRF 

is operated by a private contract operator (American 

Water, n.d.). The WRF was designed and built by the 

private contract operator and constructed adjacent to 

the stadium in order to minimize the cost of the 

reclaimed water distribution system. 

The design-build delivery of the WRF allowed a 

public–private partnership to plan and implement a 

reuse system for a major stadium. The lesson learned 

is that major private projects can be successful using a 

design and construction method that reduces risks, by 

placing that risk on a single entity. 

References 

American Water. n.d. Water Reuse. Retrieved on Sept. 5, 

2012 from <http://www.amwater.com/corporateresponsibility/corporate-responsibility-reporting/our-priorityyour-water/integrating-water-resource-management/waterreuse.html>.

Esposito, Kathleen. “The Role of Wastewater Reuse in the 

Future of Rhode Island Water Resources Management.”

February 2004.

Metropolitan Area Planning Council, 495/Metro West 

Partnership. “Once is Not Enough, A Guide to Water Reuse 

in Massachusetts.” November 2005. 

The Kraft Group. Website accessed July 2012 at 

<http://www.thekraftgroup.com/environment/

#gilletteStadium>.

Water Environment Research Foundation (WERF). 2012. 

“When to Consider Distributed Systems in an Urban and 

Suburban Context.” Retrieved July 2012 from 

http://www.werf.org/i/c/Decentralizedproject/When_to_Consi

der_Dis.aspx#table>.

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Snowmaking with Reclaimed Water

Author: Don Vandertulip, P.E., BCEE (CDM Smith)

US-ME-Snow

Reclaimed Water Use for Snowmaking

While recreational use of reclaimed water is most often 

associated with irrigation of golf courses, winter sports 

venues can also benefit from reclaimed water use as 

an alternate or supporting water source in the 

seasonal production of engineered snow. The practice 

of snowmaking by large ski resorts is increasing, 

especially with recent changes in weather patterns and 

a need to provide an adequate snow base to attract 

skiers throughout the ski season.

Snowmaking in Maine 

The use of reclaimed water for snowmaking is a 

relatively new practice, but the potential for its use to 

replace groundwater or stream-flow that could 

otherwise support domestic water supplies and aquatic 

habitat is increasingly attractive to many ski resorts. In 

the United States, the use of reclaimed water for 

snowmaking developed in New England as a means to 

allow for continued discharge of treated effluent from 

zero discharge lagoons and land application systems 

during the winter. 

The Carrabassett Valley Sanitary District (CVSD) in 

Maine operated a state permitted lagoon and land 

application site serving the Sugarloaf Mountain Ski 

Resort area. By the early 1990’s, the treatment system 

was receiving 50 million gallon (189,000 m3

) of 

wastewater per year, mostly during the winter months, 

filling the seven storage lagoons. Because cold 

climates and varied topography can limit land 

applications of treated effluent during the colder 

months, in the spring of 1994 CVSD investigated use 

of the SnowfluentTM developed by Delta Engineering of 

Ottawa, Canada. SnowfluentTM is essentially 

snowmaking during winter months with treated 

wastewater effluent as the water source for snow. 

Testing was conducted by the Maine Department of 

Environmental Protection (MDEP) during the 1994 ski 

season; with no adverse impacts observed during the 

testing period, the MDEP permitted a permanent 

system which was installed in 1995 (Nelson, 1992).

Following the first successful year of operations that 

included treatment and use of 28 million gallons 

(106,000 m3

), CVSD acquired three additional 

snowmaking towers (Figure 1) and a diesel generator, 

and later added SCADA controls to more effectively 

manage the system. Operationally, CVSD has found 

that by beginning snowmaking as freezing weather 

starts, the ground does not freeze, which aids the 

infiltration of melting snow in spring through early 

summer (Maine Lagoons online, 2012).

Another Maine site, the Chick Hill Pollution Control 

Facility serving the town of Rangeley, was completed 

in fall 1996. Seven snow guns were added in 1998 for 

winter operation with construction of the winter effluent 

storage and disposal facility. The system treats over 

14 million gallons (53,000 m3

) annually with one 28 

million gallon (106,000 m3

) lagoon and 40 ac (16 ha) 

of application fields. The Mapleton Sewer District 

(Figure 2) formed in 1965 upgraded its treatment 

facility in 2004 by adding a 5 million gallon (19,000 m3

) 

facultative lagoon, 14.5 million gallon (55,000 m3

) 

storage lagoon, and snowmaking system on its land 

Figure 1

CVSD District employee Joseph Puleo checks the 

nozzles atop a snow gun tower. (Photo credit: David 

Keith)

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application site, converting to a zero-discharge system 

and eliminating recurring discharge permit violations to 

the North Branch of the Presque Isle Stream. The use 

of snowmaking with spray irrigation allowed yearround operations using a smaller storage lagoon 

facility.

Snowmaking in Pennsylvania 

Two ski resorts in Pennsylvania are starting to include 

reclaimed water as a portion of their snowmaking 

water supply. Seven Springs Mountain Resort uses 

diluted recycled wastewater to augment the collected 

surface water it uses to make snow. The executive 

director of operations says "It's been treated, it's 

filtered, it's probably better than the pond water" 

(Nasaw, 2011). Seven Springs has developed a 

virtually closed-circuit water system for snowmaking 

and developed a potable water system that recycles 

water by treating and returning it back to drainage 

areas to recharge its sources. The water used for 

snowmaking is captured in a series of collector ponds 

at the base of the mountain, which are filled by rain, 

run-off and melting snow. During the snowmaking 

process, the water is pumped to the top of the 

mountain and then with the help of gravity, which 

minimizes energy use, it is supplied to more than 900 

snowmaking towers on the mountain. Water is stored 

on the slopes in the form of snow until the melting 

process returns it through channels to the collector 

ponds for the process to begin again (Seven Springs, 

2009).

The Bear Creek Mountain Resort general manager 

hopes to begin using recycled wastewater to make ski 

snow in the 2012 season, at a 9 to 1 ratio with 

untreated fresh water (Nasaw, 2011). The on-site 

wastewater treatment system uses biological 

treatment processes to produce reclaimed water that 

is also used for irrigation and ground water recharge.

Western Snowmaking 

In the western U.S. states, reclaimed water is viewed 

as a resource. In California, Donner Summit Public 

Utilities District in Soda Springs has a wastewater 

discharge permit that allows stream discharge, land 

application and snowmaking at Discharge Point 

“REC-1.” Reclaimed water must meet California Title 

22 standards that include a median concentration of 

total coliform bacteria in the disinfected effluent that 

shall not exceed 2.2MPN/100mL. This pPermit 

includes a provision (IV.C.12) that requires chlorine 

disinfection with a chlorine concentration/contact time 

of 450 mg-min and average NTU of 2 (CRWQCBCVR, 2009). Title 22 requirements for disinfected 

tertiary recycled water allow use of demonstrated, 

alternative disinfection processes with filtration; 

however, only chlorination is allowed under this permit.

In Cloudcroft, N.M, severe drought has caused water 

shortages that required trucking of potable water to the 

community at up to 20,000 gpd (76 m3

/d). In response 

to this shortage, the community moved forward with 

development of an integrated water conservation plan 

that includes indirect potable reuse. Cloudcroft 

implemented membrane technology to produce highly 

treated reclaimed water that would be used to 

supplement the existing spring and well water sources. 

The reclaimed water, produced using an ultrafiltration

(UF) membrane bioreactor and chloramine 

disinfection, is stored in a small reservoir. A portion of 

the water is diverted for non-potable purposes (golf 

course and athletic field irrigation) with 100,000 gpd 

(380 m3

/d) further treated with reverse osmosis (RO)

through a three stage, single-pass system using high 

rejection, low pressure thin film composite 

membranes. The RO permeate is treated with 

hydrogen peroxide and UV, and stored in two covered, 

lined reservoirs, prior to blending with spring flow and 

groundwater. The final stage in the water treatment 

process is ultrafiltration of the blended water source, 

Figure 2

Mapleton Sewer District Wastewater Treatment Facility 

sign (Photo credit: Gilles St. Pierre)

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GAC filtration, and disinfection with sodium 

hypochlorite prior to distribution in the potable water 

system.

The two streams from the water treatment process, the 

RO concentrate and UF backwash are diverted to a 

250,000 gallon (950 m3

) reservoir that stored water 

used for road dust control, construction, snowmaking 

for the ski area, gravel mining operations, forest fire 

fighting, and other beneficial purposes (Government 

Engineering, 2008).

Snowmaking in Australia 

The Mt. Buller and Mt. Stirling Alpine Resort are 

located 3 hours northeast of Melbourne. An expanded 

wastewater treatment plant can provide an additional 

503,000 gpd (2,000 m3

/d) of Class A recycled water 

for snowmaking per day. Class A is the highest 

achievable standard in recycled water in Australia and 

is allowed for use on food crops. The production of 

artificial snow requires large volumes of water and with 

global climate change induced forecasts for 

decreasing snowfalls in the future, ski resorts 

worldwide are increasing reliance on snowmaking. Mt. 

Buller has invested in this technology in order to 

provide a better, longer ski season. 

Prior to 2008, when use of reclaimed water for 

snowmaking was implemented, water was drawn from 

Boggy Creek. Treatment of Mt. Buller’s recycled water 

also provides benefits to the local environment by 

improving the quality of run-off that enters surrounding 

areas and waterways. Mt. Buller management advises 

skiers that if snow made from recycled water is 

ingested, it will not have any significant health 

implications; however, just like natural snow, once it 

hits the ground it is vulnerable to contamination by 

animals, vehicles and other skiers, so snow should not 

be eaten. In addition, Mt. Buller management plans to 

also use this reclaimed water for household use in new 

developments and for irrigating open spaces to deliver 

further benefits to the local alpine environment (Mt. 

Buller, 2012). 

References

Bear Creek Mountain Resort. 2012. Bear Creek’s Green 

Initiatives. Retrieved on March 25, 2012 from 

<http://www.bcmountainresort.com/environmentalsustainability>.

California Regional Water Quality Control Board Central 

Valley Region (CRWQCB-CVR, 2009), Order No. R5-2009-

0034 NPDES No. CA0081621, April 24, 2009

Government Engineering. 2008. Pioneering Water Reuse 

System: Necessity, Once Again, is the Mother of Invention. 

May-June 2008. Retrieved on March 25, 2012 from

<http://www.govengr.com/>. 

Maine Lagoons on Line. 2012. Retrieved on March 24, 2012 

from <http://www.lagoonsonline.com/cvsd.htm>.

Mt. Buller. 2012. Mt Buller Web Page. Retrieved on March 

25, 2012 from 

<http://www.mtbuller.com.au/Winter/Environment/WaterReuse-Project-and-Snowmaking>.

Nasaw, Daniel. 2011. Indians oppose 'recycled' sewage for 

Arizona skiing. BBC World News. Retrieved on October 19, 

2011 from <http://www.bbc.co.uk/news/magazine15176711>. 

Nelson, Leslie B., 1992. The Role Of Forest Soils In A 

Northern New England Effluent Management System,

Thesis, The University of Maine, May 1992.

Seven Springs. 2009. Seven Springs Mountain Resort 

Selected For National Environmentalism Award, May 14, 

2009. Retrieved on March 25, 2012 from 

<http://www.7springs.com/page/category.detail/nav/5358/Fa

cts-and-Figures.html>.

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2012 Guidelines for Water Reuse

Reclaimed Water for Peaking Power Plant: 

Mankato, Minnesota

Authors: Mary Fralish (City of Mankato) and 

Patti Craddock (Short Elliott Hendrickson Inc.)

US-MN-Mankato

Project Background or Rationale 

The city of Mankato, Minn., supplies reclaimed water 

for cooling water at the Mankato Energy Center 

(MEC), a peaking power plant with an ultimate design 

capacity of 640 MW (2,300 GJ/hr ). The first phase of 

the energy project was initiated in 2005 and included 

the installation of a 365 MW (1,300 GJ/hr ) plant with 

two natural-gas fired combustion turbines, two heat 

recovery steam generators, and one steam turbine 

generator estimated to operate about 60 percent of the 

year. Calpine Corporation approached the city of 

Mankato about a water supply, and through a 

collaborative process the decision was made to use 

reclaimed water for cooling water. 

Mankato uses groundwater and shallow wells under 

the influence of the Minnesota River for its potable 

supply. Aquifer limitations in the area posed concerns 

for use of the groundwater supply for the MEC. The 

local surface water supply, the Minnesota River, is 

heavily influenced by upstream agricultural land use 

and would require treatment prior to use as cooling 

water. As the power plant was being constructed, a 

fast-track project to provide new water reclamation 

facilities at the wastewater treatment facility (WWTF) 

was also initiated. Calpine’s experience with use of 

reclaimed water at other facilities, city staff that 

embraced and understood the value of reclaimed 

water for their community, and early involvement with 

the state regulatory agency provided for a 

collaborative environment for the facility 

improvements.

Capacity and Type of Reuse 

Application 

A new water reclamation building and treatment 

processes were added at the existing WWTF site 

(Figure 1). The system was sized to provide up to 6.2 

mgd (272 L/s) of water to meet the maximum water 

supply needs of the MEC. The supply is provided on 

an intermittent basis, and through 2011 the peak daily 

flow has not exceeded 2.6 mgd (114 L/s). Additional 

capacity was added to provide a peak flow of 18 mgd 

(789 L/s) for phosphorus removal, for more efficient 

operations and capacity to meet more stringent 

effluent standards in the future.

The MEC uses the reclaimed water for cooling water 

on an intermittent basis to meet peaking power needs. 

The cooling water blowdown, which is approximately 

25 percent of the reclaimed water used by the power 

plant, is returned to the Mankato WWTF for discharge 

under its NPDES discharge permit, as the power plant 

has a pretreatment permit but not a discharge permit.

The process train improvements added at the WWTF 

to provide reclaimed water include: high-rate 

clarification process with ferric chloride and polymer 

addition; cloth media disk filtration; chlorine contact 

basins; secondary pump station, and a standby 

generator. Existing sodium hypochlorite and bisulfate

chemical systems are used for disinfection and 

dechlorination.

Water Quality Standards and 

Treatment Technology 

The state of Minnesota permits water reuse projects 

on a case-by-case basis using the California Title 22 

reuse criteria (State of California, 2000) as the basis 

for design and effluent requirements. Site-specific 

Figure 1

Mankato WRF

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conditions and monitoring are applied to each unique 

permitted application. 

Mankato was required to provide tertiary treated water 

that meets a total coliform limit of 2.2 cfu/100 mL as a 

7-day median, with a maximum single sample not to 

exceed 23 cfu/100 mL and provide 90 minutes of 

chlorine contact time. The existing NPDES permit 

requirements for fecal coliform and other constituents 

characterizing the effluent discharge to the Minnesota 

River were not changed, but additional requirement for 

reuse including the total coliform limit and monitoring 

were added. Because a scalant with phosphorus in it 

is added to the MEC cooling water and the MEC 

blowdown water is sent to the city’s WWTF prior to 

river discharge, additional phosphorus monitoring was 

required to ensure the city’s phosphorus permit limits 

are not exceeded. 

Project Funding and Management 

Practices 

The new water reclamation center capital project was 

funded by Calpine Corporation. The city of Mankato 

selected an engineering firm to design the new 

processes and building, with construction provided by 

Calpine Corporation. The city owns, operates, and 

maintains the facility and there is no cost to Calpine for 

reclaimed water until cumulative operations and 

maintenance costs exceed the capital cost or 20 years 

is reached, at which time Calpine will be charged on a 

per gallon basis. A 20-year agreement was 

established with four 10-year renewal options including 

one item specifically requested by the city identifying 

that the city has priority to use reclaimed water for 

plant and other city uses. The city of Mankato is 

expanding its use of reclaimed water to include urban 

irrigation of a new city park and for street washing and 

vehicle cleaning. 

This project provided a unique opportunity for the city 

of Mankato to incorporate more flexibility in their 

operations to meet their existing phosphorus effluent 

discharge limits, as well as the ability to meet more 

stringent future limits, by adding capacity for 

phosphorus removal. The city also made 

improvements to their internal water systems to 

replace use of secondary effluent water with reclaimed 

water, which has resulted in fewer issues with effluent 

pump screen clogging and maintenance. 

Successes and Lessons Learned

While the facility has operated well since startup in 

2007, there was a learning curve related to providing a 

chlorinated supply for intermittent use. Intermittent 

production also required establishing a good 

communication system with the energy facility and 

laboratory staff to ensure efficient operations for 

intermittent demand and proper laboratory sampling. 

One impending issue for the city of Mankato and other 

Minnesota communities is the potential for new 

dissolved solids discharge limits. While many industrial 

NPDES permits have limits for chlorides, sulfates, and 

other ions, municipal WWTFs do not. For Mankato, 

this could be a concern given the MEC cooling water 

blowdown has elevated dissolved solids. It is possible 

that future partnerships like Mankato and the MEC 

may not be viable if there are new ion limits. 

This project was a collaborative partnership of an 

industry, municipality, contractor, engineer, and 

regulatory agency to provide a system to meet both 

the needs of the energy facility and the short and long 

term needs of the municipal WWTF. The energy 

facility met its schedule and continues to receive high 

quality water for their operation. Use of reclaimed 

water has reduced use of the local aquifer by 130 

million gallons per year which extrapolates to over 300 

million gallons per year with the MEC operating at 

design capacity.

The municipality has also provided a significant 

environmental benefit to the Minnesota and 

downstream Mississippi River watersheds, and helped 

numerous communities and industries delay major 

capital improvements. Mankato has supported the 

phosphorus trading permit framework established for 

the Minnesota River by using its excess capacity to 

remove phosphorus for other permitted dischargers 

that do not have the infrastructure to meet new 

phosphorus limits. The trading program resulted in 

meeting phosphorus goals for the watershed ahead of 

schedule. 

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References

State of California. 2000. Water Recycling Criteria. Title 22, 

Division 4, Chapter 3, California Code of Regulations. 

California Department of Health Services, Drinking Water 

Program, Sacramento, CA.

State of Minnesota, Minnesota Pollution Control Agency. 

2011. “Salty Discharge” Monitoring at NPDES/SDS 

Permitted Facilities.” Retrieved on February 8, 2012 from 

http://www.pca.state.mn.us/index.php/viewdocument.html?gid=16079. 

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2012 Guidelines for Water Reuse

Town of Cary, North Carolina, Reclaimed Water System

Authors: Leila R. Goodwin, P.E. (Town of Cary) and Kevin Irby, P.E. (CDM Smith)

US-NC-Cary

Project Background 

The town of Cary, N.C., conducted a reclaimed water 

feasibility study in 1997 to evaluate how best to meet 

its goals of reducing per capita water consumption by 

20 percent by 2015, to preserve the town’s allocation 

of raw water from its drinking water source, Jordan 

Lake. In June 2001, Cary became the first municipality 

in North Carolina to pump reclaimed water to homes 

and businesses for irrigation and cooling.

Capacity and Type of Reuse 

Application 

The town of Cary treats wastewater for Cary, 

Morrisville, the Raleigh-Durham International Airport, 

and the Wake County portion of the Research Triangle 

Park at its two water reclamation facilities (WRFs). 

Both the North Cary WRF and South Cary WRF have 

reclaimed water systems consisting of piping systems 

as well as bulk reclaimed water distribution stations. 

The town of Cary’s reclaimed water system began with 

several hundred customers in targeted service areas 

identified through an analysis of high irrigation 

demands and proximity to the WRFs. The system 

provides reclaimed water for irrigation and cooling for 

commercial facilities, lawn irrigation for single and 

multi-family homes, and irrigation for schools and a 

recreational complex. The system also includes bulk 

reclaimed water distribution stations at the town’s two 

WRFs for filling tanks for uses such as irrigation, road 

construction, dust control, sewer flushing, and street 

cleaning (Figure 1). 

Cary’s reclaimed water system has a production 

capacity of approximately 5 mgd (219 L/s). The system 

produces approximately 1 mgd on a peak day and up 

to 20 million gallons per month (76,000 m3

) during the 

summer. 

The North Cary WRF reclaimed water service area 

includes a 9 mgd (394 L/s) pump station and 1 million 

gallon (3,800 m3

) storage tank at the North Cary WRF 

required to meet peak day peak hour demands. It also 

includes approximately 9 miles (14.5 km) of 4- to 20-in 

(10- to 51-cm) transmission and distribution mains. 

The South Cary WRF reclaimed water service area 

includes a 1.2-mgd (52.5-L/s) pump station at the 

South Cary WRF and approximately 1.4 miles (2.3 km) 

of 8- to 12-in (20- to 30-cm) transmission and 

distribution mains. The reclaimed water pumps at the 

town’s WRF are shown in Figure 2. 

Water Quality Standards and 

Treatment Technology 

The town of Cary’s reclaimed water system was 

designed to meet the state’s mandatory treatment 

standards (Table 1). Both WRFs treat wastewater 

Figure 1

Bulk reclaimed water distribution station (Photo credit: 

David Heiser)

Figure 2

New reclaimed water pumps at the WRF (Photo credit: 

David Heiser)

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using biological nutrient removal and regularly meet 

the state reclaimed water quality standards.

Table 1 Minimum state reclaimed water quality 

standards

Parameter Daily Maximum

Maximum Monthly 

Average

BOD5 15 mg/L 10 mg/L 

TSS 10 mg/L 5 mg/L 

NH3 6 mg/L 4 mg/L 

Fecal coliform 25 cfu/100mL 14 cfu/100mL 

Turbidity 10 NTU 10 NTU

Project Funding 

The total project cost for the reclaimed water system 

including both the North Cary and South Cary WRFs 

was $11 million. The project was funded through the 

town’s capital improvement budget. 

Reclaimed water in the town of Cary currently costs 

$3.60/1,000 gallons ($0.93/m3

), which is the same as 

the town’s Tier 1 potable water use rates. Reclaimed 

water rates were set less than potable water while 

recovering a substantial part of the town’s capital cost 

for implementing the system. Use of reclaimed water 

allows customers to avoid higher Tier 2, 3, and 4 water 

rates that apply to water use greater than 5,000 

gallons (19 m3

) per month. Reclaimed water 

customers are also exempt from the town’s alternate 

day watering restrictions. The town does not charge 

customers for reclaimed water obtained at its bulk 

reclaimed water distribution stations.

Reclaimed Water Program 

Management

The town of Cary’s reclaimed water program is 

managed by a Reclaimed Water Coordinator, who is 

responsible for development of policy 

recommendations and selection of program 

alternatives; evaluating program effectiveness; 

collecting data; working with homeowners, businesses, 

and other potential reclaimed water customers; 

coordinating programs to encourage the use of 

reclaimed water; and inspecting the reclaimed water 

system for potential problems such as cross 

connections.

During implementation of its initial reclaimed water 

program, Cary sponsored numerous public education 

efforts, including public information sessions and 

hearings, fact sheets, news releases, meetings with 

homeowners groups and other potential customers, an 

education program for plumbers and contractors, and 

information on the town’s website. The town requires 

bulk reclaimed water users to complete a 1-hour 

training session in order to obtain a permit to use the 

reclaimed water. 

Expansion of the Reclaimed Water 

Program 

The town of Cary is currently expanding its reclaimed 

water system into a third service area. The town of 

Cary, Wake County, and Durham County are jointly 

implementing the Jordan Lake Water Reclamation and 

Reuse project. This project will provide reclaimed 

water from Durham County’s Triangle Wastewater 

Treatment Plant to customers in the Wake County 

portion of Research Triangle Park and to the town of 

Cary’s Thomas Brooks Park, the site of the USA 

Baseball national training center. The service area 

also includes some currently undeveloped portions of 

northwestern Cary.

The project is being financed by a State and Tribal 

Assistance Grant (STAG) from the federal government 

(administered by the Environmental Protection 

Agency) as well as the town of Cary, Wake County, 

and Durham County. The portion of this project serving 

the Wake County portion of Research Triangle Park 

and some of western Cary began operating in early 

2012 and the remainder will be completed in 2013.

The town has recently initiated a comprehensive 

master planning study to develop a roadmap for future 

expansion of the town's reclaimed water program.

References

Black and Veatch. 2007. Reclaimed Water System Master 

Plan. Prepared for the Town of Cary.

CDM Smith. 1997. Reclaimed Water and Wastewater Reuse 

Program. Prepared for the Town of Cary.

CDM Smith. 2000. Application for Modification to North Cary 

Reclaimed Water System Non-Discharge Permit 

WQ0017923. Prepared for the Town of Cary.

Town of Cary website. 2011. Retrieved on Sept. 4, 2012 

from <http://www.townofcary.org/>.

Wake County website. 2011. Retrieved on Sept. 4, 2012 

from < http://www.wakegov.com/>.

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2012 Guidelines for Water Reuse

Identifying Water Streams for Reuse in Beverage 

Facilities: PepsiCo ReCon Tool

Author: Liese Dallbauman, PhD (PepsiCo Global Operations) 

US-NY-PepsiCo

Project Background or Rationale 

The beverage industry is dependent on sustainable 

supplies of water for the ongoing survival of its 

business. Water is included within most of the final 

products, and also used within the supply chain. The 

beverage sector has taken the concept of water 

stewardship very seriously for decades, partly because 

of the direct financial impact on the business that 

water efficiency can afford through productivity 

savings, and partly because of the broader importance 

of corporate social responsibility in preserving water 

supplies and using water resources wisely. 

Capacity and Type of Reuse 

Application 

The Beverage Industry Environmental Roundtable 

(BIER) is a technical coalition of leading global 

beverage companies working together to advance 

environmental sustainability within the beverage 

sector. Formed in 2006, BIER aims to accelerate 

sector change and create meaningful impact on 

environmental sustainability matters. Through 

development and sharing of industry-specific analytical 

methods, best practice sharing, and direct stakeholder 

engagement, BIER accelerates the process of analysis 

to sustainable solution development.

Each year, the industry water dataset continues to 

grow in size, with 2011 representing the most robust 

report to date, including over 1,600 facilities distributed 

across six continents. Analyses were conducted to 

determine industry water use, production, and water 

use ratio over the three year period from 2008 to 2010. 

Over this period, the industry aggregate water use 

ratio improved by 9 percent, avoiding the use of 

approximately 39 billion liters of water in 2010—enough 

water to supply the entire population of New York City 

for 8 days. So the beverage industry as a sector has 

been quantitatively using water more efficiently. An 

important part of water efficiency practices is 

identifying opportunities for water reuse. 

Project Funding and Management 

Practices 

At PepsiCo, ReCon is the name given to our corporate 

global set of best practice tools for resource 

conservation. The first tool was constructed several 

years ago for energy management within the beverage 

production plants, based heavily on tools and 

information from the U.S. Department of Energy. The 

ReCon suite has grown to include ReCon Water, 

ReCon GHG, and ReCon Waste. The power of these 

tools comes from leveraging a common approach. 

Each first quantifies a plant’s resource usage streams 

and sub-streams and calculates the relative value of 

the streams. In the case of water, for example, the 

online ReCon Water Profiler allows the plant to dissect 

its water use and then provides a mapping of the 

relative volumes and values of each stream (Figure 

1). The values are determined based on local cost of 

incoming water, treatment or conditioning chemicals, 

energy used to heat or cool prior to use, and finally 

costs associated with discharge. 

Figure 1

Example output from Recon Water Profiler that 

compares water use volume for different uses at a 

beverage plant

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Comparing these data allows a quantitative 

assessment of which streams offer the greatest 

opportunities for saving water, whether by avoiding 

water use altogether, reducing the volume of water 

used, or reusing spent water. The Diagnostic, a series 

of customized audit-type questions, then assesses 

whether the plant is following best practices, and 

which opportunities exist for improvement. 

Involvement of the plant’s quality organization ensures 

that any changes in water use practices meet strict 

quality standards.

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2012 Guidelines for Water Reuse

The Water Purification Eco-Center

Authors: Jeff Moyer and Christine Ziegler (Rodale Institute)

US-PA-Kutztown

Project Background/Rationale 

The Water Purification Eco-Center (WPEC) is a 

decentralized wastewater treatment and disposal 

system for Rodale Institute’s new Visitor Center in 

Kutztown, Pennsylvania. Rodale Institute is a nonprofit 

research, education and training facility. The WPEC 

Project was developed to maintain and demonstrate 

an on-site wastewater treatment system that captures 

rainwater and uses it several times before returning it 

to the soil as clean water. The system, which 

incorporates a cistern, a septic/equalization tank, a 

constructed wetland cell, a trickling filter, and 

subsurface drip irrigation disposal unit, utilizes 

wastewater as a resource, demonstrating an 

alternative to standard septic and sand mound on-lot 

sewage systems. This system is scalable and can be 

used in sustainable landscapes for small commercial 

entities as well as residential units (Figure 1).

Capacity and Type of Reuse 

Application 

The system demonstrates wastewater treatment 

utilizing natural systems, as well as resource 

conservation and recycling. The system was 

constructed to provide fresh, collected and/or recycled 

water source to toilet fixtures designed to conserve 

water. Effluent passes to a dual-compartment septic 

tank, and then on to a flow equalization tank to provide 

uniform flow rates and to allow compensation for 

intensified use. Wastewater is then directed through a 

wetland treatment cell, where soil biology and plant 

roots utilize excess nutrients from the water, where 

pathogens are also neutralized. Once wastewater has 

passed through the wetland treatment cell, it is sent to 

a trickling filter and then back through the wetlands 

cell. Finally, the treated water is directed to the 

subsurface irrigation system servicing the landscaped 

areas surrounding the Visitor Center. 

The design capacity of the system is 400 gpd 

(1.5 m3

/d) and flow equalization allows the system to 

address a peak flow of 800 gpd (3 m3

/d). This is the 

typical size used for a single residence, minus the flow 

equalization tank, which was added to account for 

usage patterns specific to a visitor center.

Water Quality and Treatment 

Technology 

Water quality tests at several points in the system 

allow researchers to capture information on how the 

various treatment stages are working. Annual 

sampling of the surrounding soils will indicate the 

impacts of the system on its immediate environment, 

demonstrating how the wetlands system design can 

achieve and surpass EPA discharge standards for 

secondary effluent.

Many watersheds in the state of Pennsylvania house 

residential communities with on-lot sewage systems 

located within their boundaries, and the numbers are 

growing daily. The materials leaving these systems, if 

treated properly are no longer to be viewed as waste 

products; rather, they need to be viewed as resources. 

The proper use of these resources can have a 

profound impact on land use and water quality in the 

areas where they are located. Viable and practical 

alternatives to both standard septic and sand mound 

systems are needed for residential communities using 

on-lot sewage systems. 

The water quality objective of this project is to

transform standard septic effluent into clean water that 

will meet EPA discharge standards for secondary 

effluent, while affecting no net change in the nutrient 

parameters of the soil or water surrounding the 

system. In order to achieve this objective, each 

component of the treatment system must be 

functioning properly. Thus, treatment component 

integrity is being assessed through analysis of monthly 

water samples drawn from lysimeters (porous access 

tubes) located in the surrounding soil, and component 

function will be assessed through analysis of monthly 

water samples collected at the outflow of each 

component, and at the end of the system. All water 

samples are being collected and processed in 

accordance with standard operating procedures and 

the analysis being conducted by MJ Reider and 

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Associates, Inc. laboratory is being assessed for 

statistical changes in nutrients and other 

contaminants.

Project Funding and Management 

Practices 

The WPEC project is funded by the EPA 

(Congressionally Mandated Projects - Wetlands for the 

Prevention of On-Lot System Pollution, Agreement 

Number XP-83369301-0, CFDA Number 66.202), the 

Pennsylvania Department of Environmental Protection, 

Rodale Institute and other corporate and private 

funders. The Berks County Community Foundation 

has also provided funding for addition of solar panels 

to the facility. 

This project is managed as a research and education 

facility, to highlight the viability and functionality of the 

system as an alternative to traditional sewage 

management. A broad cross-section of society is being 

education on concepts and principles of regeneration 

that are applied through the system. The intended 

audiences include two main groups. First, on the 

demand side, are those who want or need a 

decentralized system. Second, on the supply side, 

there are those who will provide and regulate the 

systems. These groups include elementary school 

children, municipal officials, land developers, 

watershed management groups, planning 

commissioners, policy makers, and sewage 

enforcement officers. Rodale Institute is also reaching 

out to those who cannot visit the center, in person, 

through a distance learning program and information 

on the project website. 

Institutional/Cultural Considerations 

Since the grand opening of the facility in 2011, 

outreach and education efforts have included 

development of an informational project brochure, 

newsletter features, site tours that include an 

electronic kiosk featuring informational text, animation 

of the whole system and interactive games that test 

visitors’ knowledge of water-related issues. Other 

educational outreach has included on-site and off-site 

speaking engagements and workshops. The first onsite workshop, entitled “Constructed Wetlands in 

Wastewater Treatment,” was conducted in June 2011 

and a second workshop was held in June 2012. 

Rodale Institute is also arranging continued speaking 

engagements at targeted tradeshows that will help 

increase understanding and expand use of wetland 

technology. 

The WPEC has been featured in local, regional and 

national print publications and in electronic media. A 

Rodale Institute website re-design in 2012 will 

enhance capacities to present the WPEC in a clear 

and accessible manner for a wider range of audiences. 

Other Water Purification projects across the nation that 

have similar goals, and fit with the mission of Rodale 

Institute will be featured on the website.

Successes and Lessons Learned

The facility was considered “on-line” as of the grand 

opening in June 2011 and the systems have been up 

and running, as designed, since October 2011 

purifying wastewater without any issues. Continuous 

monitoring allows tracking system performance and 

will allow minor adjustments to optimize the operations 

of each individual component of the system. 

Some minor issues with automated controllers were 

experienced in early stages of this system. Water float 

control adjustments and pump timing changes have 

been made. Once tested and confirmed effective, the 

adjustments will be shared in project trainings and 

documentation. Also, water sampling protocols have 

been finalized and sampling is in the early stages. 

Once several months of data have been collected, 

information will be shared and possible system 

adjustments will be made, if needed. This shared 

information will be helpful to other institutions and 

private individuals who may choose to install similar 

systems for their projects, properties and landscapes.

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Figure 1

Schematic of the WPEC system components (Photo credit: Rodale Institute and NEWVISION Communications)

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2012 Guidelines for Water Reuse

Zero-Discharge, Reuse, and Irrigation at Fallingwater, 

Western Pennsylvania Conservancy

Author: Mike Wilson, P.E. (CH2M Hill)

US-PA-Mill Run

Project Background or Rationale 

In 1999, the Western Pennsylvania Conservancy 

(WPC) implemented a water reuse plan at Fallingwater 

to promote sustainable design principles and reduce 

potable water use through a zero-discharge 

wastewater reclamation system. Fallingwater, the 

world-famous “house on the waterfall,” was designed 

and built by Frank Lloyd Wright—one of the most 

important architecture and design figures of the 20th 

century. The Main and Guest Houses were 

constructed in the 1930s and the Main House (shown 

in Figure 1) was cantilevered over a waterfall located 

on Bear Run, a stream of “exceptional value” as 

categorized by the state of Pennsylvania. 

Capacity and Type of Reuse 

Application 

The visitors' center and onsite facilities produce 

approximately 8,000 gpd (30 m3

/d) of wastewater. The 

wastewater is pumped to the treatment facility, which 

is housed in a separate 1,800-square-foot (194 m2

) 

structure located away from the main house 

(Figure 2). The system recycles 100 percent of the 

wastewater that is produced by the facility’s 140,000 

annual visitors. 

The treatment processes include an MBR followed by 

carbon adsorption and UV disinfection. The process 

produces an effluent suitable for public access reuse. 

Following treatment, the reclaimed water is recycled 

for use as toilet flush water at the visitor's pavilion, and 

at other site buildings. The system also includes 

irrigation of a forested site with a subsurface drip 

irrigation system to provide redundant reuse capacity 

during the winter months and wet periods. 

Water Quality Standards and 

Treatment Technology 

The membrane bioreactor treats wastewater to the 

reuse standards required by the Pennsylvania 

Department of Environmental Protection (DEP) as 

shown in Table 1. 

Figure 2

Treatment facility (Photo credit: WEFTEC 2002)

Figure 1

Main House (Photo credit: WEFTEC 2002)

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Table 1 Typical water quality 

Parameter Raw Water Effluent

BOD (mg/L) 350 < 5

TSS (mg/L) 350 < 5

TN (mg/L) 75 <10

Turbidity (NTU) — < 2

Project Funding and Management 

Practices 

The project was paid for by the Conservancy Trust. 

The entire project cost $15 million and was completed 

as a design-build project. The system was put into 

operation in 2005. This approach provided a single 

point of accountability and allowed the conservancy to 

provide critical input to all project phases. 

Successes and Lessons Learned

The project provided the conservancy with an 

opportunity to include sustainable design practices in 

their mission of environmental stewardship. The 

project had the added benefit of educating the public 

on an innovative sustainable water reclamation 

process and the benefits of reuse. The Fallingwater 

Wastewater Pumping, Treatment, and Reuse Systems 

won the National Design-Build Award for water 

projects under $15 million in 2005. The wastewater 

reclamation system can be a model for other sites 

facing similar constraints in the Northeast.

References

Brubaker, G.F., L. Waggoner, K. Speer, and C. Edwards. 

2002. “Preserving the Fallingwater Environment by 

Implementing a Zero-Discharge Wastewater Reclamation 

System.” Proceedings of WEFTEC 2002, Water 

Environment Federation. 

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2012 Guidelines for Water Reuse

Franklin, Tennessee

Integrated Water Resources Plan

Authors: Jamie R. Lefkowitz, P.E. and Kati Bell, PhD, P.E. (CDM Smith); and 

Mark Hilty, P.E. (City of Franklin)

US-TN-Franklin IWRP

Project Background or Rationale 

Located 20 miles south of Nashville, the city of 

Franklin, Tenn., is a rapidly growing community of 

approximately 60,000 people. Franklin is one of the 

fastest growing cities in the nation—twice as many 

people live in the city today compared to a decade 

ago. And the trend is expected to continue: Franklin’s

population is projected to double again during the next 

30 years. The rapid growth in Franklin is placing 

pressure on capacities for drinking water supply and 

wastewater treatment, along with increased 

maintenance of the collection, distribution, and 

stormwater infrastructure. As a result, the city faces a 

tremendous need for water resources planning in 

order to continue providing reliable water, wastewater, 

and stormwater services to its growing residential and 

commercial user base. These services must be 

provided to support growth, while protecting 

community’s most valuable and resource—the 

Harpeth River.

Reuse is one key aspect of an integrated plan 

developed by Franklin to determine a course of action 

for water resources projects over the next 30 years. 

Currently, the city provides drinking water 

(approximately one-third from its own treatment plant 

and two-thirds from wholesale purchase), wastewater 

treatment, and reclaimed water for irrigation. Raw 

water is withdrawn from the Harpeth River for 

treatment at the Franklin drinking water plant, and 

treated wastewater effluent that is not further treated 

and reused for irrigation is discharged to the Harpeth 

River.

Capacity and Type of Reuse 

Application

Franklin’s reuse system is fed directly from the 

wastewater reclamation facility (WWRF) that receives 

and treats almost all of the city’s wastewater. The 

WWRF capacity is currently 12 mgd (526 L/s) and as 

of 2012 operates at approximately 80 percent of its 

permitted capacity. All wastewater treated at the plant 

receives tertiary treatment through a biological 

denitrification filter following secondary biological 

treatment, is of exceptionally high quality, and is 

available for reuse. 

The reuse distribution system was installed in 1992 

when the city entered into an agreement with a local 

golf course to supply reclaimed water for irrigation. 

The distribution system currently consists of a 7.5 mgd 

(329 L/s) pump station and more than 15 miles (24 

km) of distribution pipelines. The distribution system 

delivers reclaimed water to customers that have 

connected to the reuse network and includes golf 

courses, residential communities, commercial 

developments, a recreational facility, and the high 

school. The highest demands occur in July and August 

averaging 2.6 mgd (114 L/s) in 2011; however, when 

considering daily peaking factors, there have been 

days when reclaimed water is not available to meet 

reuse demand.

Integrated Planning Process 

In order to meet water resources demands of the 

growing population, Franklin must expand the capacity 

of its WWRF. The first step in this process is to obtain

new discharge permits under the challenging 

regulatory situation involving water quality impairments 

in the Harpeth River. A total maximum daily load 

(TMDL) was completed for the Harpeth River in 2001

that defined stringent waste load allocations for the 

Franklin WWRF through its National Pollutant 

Discharge Elimination System permit. Faced by these 

challenges, the city opted to take a more holistic look 

at how it manages its water resources. The result was 

an integrated plan that would not only satisfy the 

wastewater and reclaimed water demands, but also 

provide long-term, sustainable solutions to Franklin’s 

water challenges, and environmental enhancements to 

the Harpeth River. 

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In 2010, city officials, administration and staff 

embarked on a 2-year process to evaluate Franklin’s 

water resources from a long-term, holistic perspective 

encompassing water supply and treatment, 

wastewater collection and treatment, biosolids 

treatment and disposal, reclaimed water distribution, 

stormwater management, ecological preservation, and 

restoration in the Harpeth River and its tributaries. 

Franklin decided that a facilitated, stakeholder process 

would be the best means to develop a broadly 

acceptable Integrated Water Resources Plan (IWRP). 

As a result, a broad range of representatives from city 

administration and staff, state regulatory agencies, the 

county, neighboring utilities, environmental advocates, 

and the community were involved in developing the 

project goals, objectives, performance measures and 

alternatives, and ultimately the recommended plan.

The Integrated Model 

Franklin’s water resources are a network of natural 

and man-made systems that satisfy demands on water 

(e.g., irrigation, industrial use, human consumption, 

habitat, and recreation). Water moves between these 

network segments through completely natural, altered 

natural, and manmade pathways. In order to conduct 

an alternatives evaluation of various sets of 

stakeholder-derived project options, a simulation 

model of the city’s water resources system was 

developed to represent the system’s segments and 

their interconnectivity. 

An integrated network model was developed to 

represent the city of Franklin’s water resources 

system, allowing the physical flow systems to be 

modeled with operational and planning level 

resolution. The integrated model was developed 

utilizing the STELLA software tool (Systems Thinking 

Experimental Learning Laboratory with Animation), 

which is a dynamic and graphical tool used to simulate 

interactions between, and within, subsystems that are 

part of a larger interconnected system. Because 

dozens of alternatives were identified by stakeholders 

(alternate water sources, use and reuse options, 

operational triggers, etc.), this tool was able to rapidly 

help screen information, identify key drivers, and 

understand the causal relationships throughout the 

complex water system.

The integrated model was divided into segments which 

represent the categories of the city’s water resources: 

the Harpeth River, water supply, wastewater, 

reclaimed water, and stormwater. These sectors of the 

water resources system are interconnected so 

decisions or policies aimed at managing water within 

one sector often has direct effects and interacts with 

the other systems. For example, increasing the volume 

of reclaimed water use would effectively decrease 

demand on the potable water supply and treatment 

associated with irrigation demand; however, it would 

also decrease the volume of water returned to the river 

limiting supplemental flows during potential low-flow 

periods.

Evaluating the Benefit of Reuse 

One of the most challenging and interesting 

components of the Franklin IWRP process was 

analysis and integration of the wastewater, reuse, and 

potable water systems. The initial driver of this project 

was addressing issues associated with the existing 

WWRF. Already in excess of its design capacity, the 

WWRF was evaluated to determine how much 

additional capacity could be achieved while meeting 

the anticipated permit limits for nutrients in the Harpeth 

River; nitrogen was the limiting factor for this project. 

Topography of the service area and previous 

development of the collection system in the city 

provides gravity flow of wastewater that could be split 

and routed to two separate locations. The first location 

is the existing facility and the second is a site where a 

facility in the southern portion of the city’s service area 

could be constructed. The southern WWRF site is 

located approximately 3 river miles upstream of the 

existing drinking water treatment plant (WTP), and 

could provide additional benefits of augmented flows 

upstream of the WTP intake, particularly during 

seasonal low flows.

As part of the integrated plan, the probable increase in 

demand for reuse irrigation water was estimated 

based on potential new customers located near 

existing lines and could tie-in without a substantial 

capital expenditure by the customers or the city. The 

level of less-certain demand for the reuse water was 

also estimated. To serve these customers, new lines 

would need to be constructed and current 

development trends would need to continue. While 

less certain, the future reuse demands could increase 

the potential for reuse more than the base case, but 

only if the city completes infrastructure projects to treat 

and distribute the reuse water, and the anticipated 

development within Franklin results in a significant 

increase in wastewater volume for reuse supply. 

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Increased reuse would help relieve non-potable 

irrigation demands, as well as alleviating nutrient 

discharges to the Harpeth River, allowing permitting 

and implementation of capacity expansion to meet the 

future wastewater demands. Results of the model 

demonstrated that increasing reuse was the key to 

implementing projects to address future wastewater 

demands, as shown in Figure 1. This graph compares

the nutrient loading for the future wastewater capacity 

with no increases in the reclaimed water capacity to

the IWRP alternative that results in reduction of 

nitrogen loading to the river by meeting the probable 

future reuse demands with reclaimed water (using

projected 2040 wastewater flows). 

Project Funding and Management 

Practices 

Reclaimed water in Franklin has historically been used 

for non-potable uses such as irrigation. Although 

middle Tennessee is a water-rich region and potable 

water is sometimes used for irrigation, the cost of 

distributing potable water makes it increasingly 

attractive for customers to irrigate with reclaimed water 

instead. As with wastewater utilities across the 

country, Franklin’s current water and sewer rates do 

not keep pace with infrastructure maintenance costs. 

However, providing low-cost reclaimed water allows 

the city to treat and purchase less potable water 

through its wholesaler by reducing overall demand for 

the relatively expensive commodity. 

Institutional/Cultural 

Considerations 

The inclusion of reuse in Franklin’s 

integrated water resources plan 

allows the city to consider the 

complete water use cycle when 

planning for future growth. Utilizing 

reuse water gives the city flexibility 

in water supply and wastewater 

demand to better meet the needs of 

customers and environmental 

requirements. The final preferred 

option that was developed through 

a stakeholder process included 

future construction of a new WWRF

upstream of the city where much of 

the new development is expected 

and where that wastewater would 

flow to the plant by gravity. To fully implement this 

plan, however, the public perception issues associated 

with discharging wastewater effluent upstream of the 

water treatment plant intake will require continued 

public outreach and communication. 

Successes and Lessons Learned

The Harpeth River is a small river that is impaired with 

respect to dissolved oxygen and nutrients which 

creates challenges for permitting additional 

withdrawals and discharges. The use of reclaimed 

water is an essential part of planning for increased 

water service capacities in the city of Franklin; 

increased reuse can allow the city to meet stringent 

effluent permit limits by reducing nutrient loads to the 

receiving stream while also reducing demand for 

potable water. Franklin is only one of a handful of 

cities in the state of Tennessee with a centralized 

reuse treatment and distribution system that is serving 

as a model for other communities wishing to adopt the

sustainable practice of integrating reuse into water 

resources management.

To address these needs, the IWRP was developed 

using a facilitated process involving stakeholders to 

assist with the definition of the goals, objectives, 

performance measures and alternatives, and 

ultimately the recommended plan as the final product. 

One of the most critical components in development of 

the plan was the transparency in the technical 

evaluations and stakeholder involvement in the 

planning process. Ultimately, adoption of the final 

IWRP, which identifies projects that would be 

Figure 1

Estimated reduction in nutrient loading to Harpeth River resulting from 

increased effluent reuse

Total Nitrogen Limit, 

Summer Conditions

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adaptively implemented in phases over the next 30-

year planning period, would not have been possible 

without this stakeholder participation. 

References

City of Franklin, Tenn., website. n.d. “Integrated Water 

Resources Planning.” Retrieved on August 20, 2012 from

<http://www.franklintn.gov/index.aspx?page=618>. 

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San Antonio Water System 

Water Recycling Program

Author: Pablo R. Martinez (San Antonio Water System)

US-TX-San Antonio

Project Background or Rationale 

The Edwards Aquifer is the primary water source for 

San Antonio, serving a population of 1.3 million. 

Reclaimed water is one resource in the San Antonio 

Water System (SAWS) water supply portfolio along 

with conservation and surface water. The SAWS 

continues to plan and develop additional water 

resources to meet current and projected demands and 

as a result, has a nationally recognized reclaimed 

water program designed to deliver 35,000 ac-ft/yr (43 

MCM/yr) to customers using the product for stream 

augmentation, irrigation, cooling towers and industrial 

processes. The system includes 130 miles (210 km) of 

distribution pipeline, in-line storage tanks, and 

pumping facilities to deliver reclaimed water produced 

at three Water Recycling Centers (WRCs).

Capacity and Type of Reuse 

Application 

Reclaimed water is produced at the Dos Rios, Leon 

Creek and Medio Creek WRCs, which have a 

combined capacity of 233 mgd (10,200 L/s). Above 

ground storage tanks provide in-line storage for 

reclaimed water which is distributed through 130 miles 

(210 km) of pipe ranging in sizes from 42-in to 24-in 

(107 cm to 61 cm) in diameter. The system is 

comprised of two major branches. Capacity in the east 

leg is 13,000 ac-ft/yr (16 MCM/yr) and capacity in the 

west leg is 22,000 ac-ft/yr (27 MCM/yr). At this point, 

both legs are near capacity with agreements for 

reclaimed water service. The reclaimed water is used 

for a range of uses, as shown in Figure 1. 

Water Quality Standards and 

Treatment Technology 

The state of Texas recognizes two types of reclaimed 

water quality (Type I and II). SAWS’ WRCs produces 

type I reclaimed water, as shown in Table 1. The 

treatment technology used to meet these standards is 

advanced secondary treatment, filtration and chlorine 

disinfection at the WRCs and system high service 

pump and storage facilities. The reclaimed water 

quality falls under the responsibility of WRC operators 

who provide that reclaimed water is treated to 

regulatory and contractual standards.

Figure 1

Reclaimed water use in ac-ft/yr and percent

The reclaimed water infrastructure maintenance is 

conducted by existing distribution and operations 

personnel and includes daily equipment checks, 

monitoring chlorine feed rates and addressing any 

system concerns or maintenance when needed. 

Table 1 Standard and SAWS reclaimed water quality

Constituent

Type I Standard 

(Texas)

SAWS 

Reclaimed Water 

Quality

BOD5 5 mg/L 2 mg/L

Turbidity 3 NTU <1 NTU

Fecal Coliform <20 cfu/100 mL <2 cfu/100 mL

Project Funding and Management 

Practices 

Funding for the reclaimed water system infrastructure 

(pipelines, storage tanks and pumps) was supported 

through the existing capital program with support from 

a state loan program. Initial capital cost for the system 

was $124 million. The cost for reclaimed water is 

about $1.00/1000 gallons ($0.26/m3

). Commercial, 

Rivers and 

streams, 

10,106, 51%

Industrial & 

cooling, 

2,702, 14%

Government 

and other 

irrigation, 

3,678, 19%

Golf courses, 

3,166, 16%

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potable water can cost $2 to 3/1000 gallons ($0.52 to 

0.77/ m3

) depending on the customer’s rate structure, 

seasonal and out of city limit rates plus water supply 

and Edwards Aquifer Management Fee based on 

volume and stormwater fee based on size of property.

Institutional and Cultural 

Considerations 

When the reclaimed water program was developed, 

management and operational aspects were not 

formulated into designated departments or 

organizations. All planning, design, operations and 

customer service responsibilities were incorporated 

into existing water utility functions. 

San Antonio is most notably known for its Downtown 

Riverwalk, which is the cultural center of San Antonio 

and visited annually by millions of visitors, aside from 

those who live in San Antonio. Approximately 4.6 mgd 

(200 L/s) of reclaimed water can flow into the 

Riverwalk; thus, stakeholder input to address issues 

such as water quality, policy and rates was critical. 

Public involvement included informational packages 

and numerous public presentations to gain confidence 

from the ratepayers that the program was a viable 

alternative non-potable water project. 

Successes and Lessons Learned 

The key factors to ensure project success included 

three phases of implementation: 

Planning phase. Public opinion can change from 

skepticism to acceptance, and building public trust 

takes work to gain and keep. Stakeholders (citizens, 

government leaders, business leaders and 

organizations, schools) were included in information 

fairs and presentations to educate the public on the 

pressing need to manage the local water resources 

better for all. 

In San Antonio, the federal lawsuit over endangered 

species was front page news for several years. The 

lawsuit covered seven endangered species and ruled 

that pumping water from two springs for urban and 

agriculture use had to be curtailed to support minimum 

flows in two springs to protect the endangered 

species. Most of the individuals engaged in discussion 

of building a reclaimed water system knew San 

Antonio lost 20 percent of its water supply with the 

judge’s ruling. SAWS presented a reasonable option to 

maintain quality of life for the community and minimize 

impact on water/wastewater rates.

Operations staff were included in initial planning and 

worked with water resources staff and customers to 

help provide a reclaimed water system to meet 

customer needs. Because staff were involved, they 

were accountable for the reclaimed water program’s 

success. 

Construction phase. It is common to coordinate with 

impacted neighborhoods by holding town hall 

meetings and information fairs in advance of 

construction. Because reclaimed water was a new 

utility bringing a new water supply, many residents had 

concerns about potential health impacts of reclaimed 

water. SAWS staff collected three samples of water in 

large glass containers (potable water, reclaimed water 

and San Antonio River water) for the information fairs 

and neighborhood meetings and most residents 

quickly excluded the river water but could not visually 

determine which jar contained potable or reclaimed 

water. This simple visual experience convinced many 

that reclaimed water was acceptable and clearly not 

sewage.

River discharge of reclaimed water is a benefit in 

urban environments; and once politicians were 

convinced reclaimed water was an acceptable 

alternative, the benefits of increased baseflow in the 

river and Riverwalk area downtown were evident to 

most businesses in the area, reinforcing the need for 

reclaimed water.

Operations phase. Get over the “us and them” 

attitude in organizations. The reclaimed water program 

at SAWS merged into previously distinct areas of the 

organization (water and sewer) and staff worked 

together to meet the program needs with their 

individual experience base. There were challenges 

such as chlorine dosing at low flows during system 

startup. When final phases of the project with 

rechlorination systems were complete, higher quality 

water was obtained in all parts of the distribution 

system, eliminating the few customer complaints that 

had been received.

Acknowledging that issues will happen (i.e. cross 

connections) in the best of reclaimed water systems 

and develop customer and staff training programs to 

educate all involved with immediate steps to resolve 

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cross connections, pipe failures, or other anticipated 

actions.

References

Pape-Dawson Consultant Team, Pape-Dawson Consulting 

Engineers, Inc. San Antonio Water System Water Recycling 

Program Engineering Feasibility Report, p. 3-29. October 

1996. 

San Antonio Water System website. 2011. Retrieved on 

Sept. 5, 2012 from <http://www.saws.org>. 

Eckhardt, Gregg. The Edwards Aquifer Website. Retrieved 

on August 02, 2012 from <http://www.edwardsaquifer.net/>.

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2012 Guidelines for Water Reuse

Raw Water Production Facility: Big Spring Plant

Author: David W. Sloan, P.E., BCEE (Freese and Nichols)

US-TX-Big Spring

Project Background or Rationale 

Aiming to “reclaim 100 percent of the water, 100 

percent of the time,” the Colorado River Municipal 

Water District (CRMWD, the District) in Texas 

anticipates launching operation of its first water 

reclamation plant in 2012 as step one in its ambitious 

program. In developing this plan, a 2005 feasibility 

study included the following:

 An inventory of effluent quantity and quality

 Determination of quality requirements for 

various blending scenarios

 Initial coordination with state regulators

 Concept-level cost estimates

 Development of a public information strategy

The Permian Basin of West Texas has always been 

challenged with water supply issues, and like much of 

the southwestern United States, has been subject to 

extended periods of low rainfall through the early 21st 

century. Since 1996, long-term drought has resulted in 

dangerously low reservoir levels prompting providers 

to consider new water supply sources. Water reuse 

has been practiced in the region for decades, and is 

increasing with application of new concepts in supply 

integration. 

The CRMWD supplies water to its member cities: Big 

Spring, Snyder, and Odessa, Texas, as well as several 

customer cities such as Midland. The population of the 

CRMWD service area is about 350,000. Key 

components of CRMWD’s water reclamation plan 

include:

 Facilities to capture treated wastewater effluent 

prior to discharge

 Local and regional reclamation facilities to purify 

captured water

 Blending facilities to combine the reclaimed 

water with other raw water supplies

Although treatment facilities and transmission costs 

will be significant, CRMWD anticipates savings over 

other raw water source development options and a 

reduction in long-distance pumping costs. Three 

projects are envisioned, with a potential net average 

yield of 13 mgd (570 L/s).

Capacity and Type of Reuse 

Application 

The District has proceeded with implementation of its 

first project, near CRMWD headquarters in Big Spring. 

This project will intercept up to 2.5 mgd (110 L/s) of 

filtered secondary effluent from the City of Big Spring 

WWTP and transfer it to an adjacent site, where 

additional treatment will be provided. The additional 

processes consist of microfiltration (MF), reverse 

osmosis (RO) and advanced oxidation prior to 

blending with raw surface water in the District’s raw 

water transmission pipeline as shown in Figure 1. 

Project construction began in June 2011, with startup 

of treatment and transmission anticipated in fall 2012. 

Reclaimed water will represent up to 15 percent of the 

blended raw water in the existing pipeline network 

supplying member and customer cities, which operate 

conventional surface water plants which will continue 

to provide final treatment, including disinfection, prior 

to distribution.

Water Quality Standards 

Due to the unique nature of this project—it is the first 

system in North America that directly blends reclaimed 

water with raw drinking water supply—there were no 

existing regulations or water quality standards that 

would drive specific treatment goals. The District 

worked closely with the Texas Commission on 

Environmental Quality to confirm that the proposed 

project approach and treatment level would be 

acceptable to protect public health and comply with 

source water approval regulations.

Treatment Technology 

The established systems of the Orange County Water 

District in California and the Singapore NEWater 

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facilities provided an established treatment approach 

for high-exposure potable reuse. This treatment 

precedent was determined to be applicable for this 

project. 

In selecting treatment processes, local conditions were 

considered. The use of natural systems such as 

wetlands or reservoirs was precluded due to high 

evaporation rates. In lieu of such an option, a rigorous, 

multi-barrier mechanical treatment scheme was 

deemed necessary. Water supplies in the District are 

high in dissolved solids, which are then further 

concentrated in the treated wastewater effluent. 

Desalination was therefore indicated as an essential 

element of the proposed treatment to meet total 

dissolved solids (TDS) standards for drinking water 

supply.

In the CRMWD plant system, MF provides removal of 

particulate material, including protozoan cysts resistant 

to chemical disinfection. RO provides removal of 

dissolved salts, viruses and bacteria, as well as many 

trace compounds such as pharmaceuticals and 

personal care products. Advanced oxidation with UV 

and hydrogen peroxide provides an additional barrier 

to potential pathogens and trace contaminants, not 

amenable to removal by RO.

Project Funding 

The project has been funded primarily by District 

revenues from the sale of raw water. The initial 

feasibility study and preliminary design report were 

funded in part by a state water supply planning grant, 

which represented approximately 

22 percent of the cost for those 

phases of the project. 

Construction is funded by a state 

loan program available for 

financing new water supplies. 

Study costs were approximately 

$440,000 and costs of design and 

construction of the reclamation 

plant and transmission facilities 

are approximately $13.6 million.

Institutional/Cultural 

Considerations 

Local public awareness regarding 

scarcity of water and an 

independent, pioneering spirit 

have contributed to acceptance of 

the reuse concept by the Permian 

Basin communities. The area’s historic struggle to 

develop a dependable supply of potable water has 

resulted in a profound local understanding of the 

area’s needs. 

The District has developed a transparent process to 

inform the public throughout the project. Public 

meetings were held near completion of the initial 

feasibility study and again during preparation of the 

preliminary design report. Numerous media releases, 

radio announcements, and website descriptions have 

been provided to raise awareness of the concept and 

the developing project. The District developed 

literature and illustrations to distribute at meetings and 

generally as the project progressed.

Successes and Lessons Learned

Open, proactive communications with state regulators 

and the public have been key to the success of this 

project, along with the open-minded evaluation by 

regulators and public. Lessons learned include 

recognition of the time required for working out 

agreements with other entities, such as the member 

cities of the District.

Figure 1

Project schematic, Raw Water Production Facility – Big Spring Plant

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2012 Guidelines for Water Reuse

Site Suitability for Landscape Use of Reclaimed Water in 

the Southwest

Authors: Seiichi Miyamoto, PhD and Ignacio Martinez 

(Texas A&M Agrilife Research Center at El Paso)

US-TX-Landscape Study

Project Background 

As population and demand for potable water increase, 

reuse of reclaimed water for landscape irrigation is 

becoming a more attractive practice in many 

communities in the U.S. Southwest. It saves potable 

water, and provides a stable supply of irrigation water 

for maintaining urban greenery and recreational 

facilities. While the objective of conserving potable 

water is being achieved, there have been cases of 

landscape quality degradation at some reclaimed 

water use sites including foliar damage, stunted 

growth, early defoliation, and at times, tree mortality. 

Reclaimed water in west Texas and southeastern New 

Mexico has elevated salinity, up to 1650 ppm 

(Table 1). The sodium adsorption ratio (SAR) is highly 

variable, but typically ranges from 7 to 12 in the Rio 

Grande watershed, and 2 to 3 in other areas. For 

comparison, salinity of reclaimed water used for 

landscape irrigation in California is generally less than 

750 ppm, rarely exceeding 1000 ppm. 

Type of Reuse Application 

This study was conducted in five project areas where 

reclaimed water was used for urban landscape 

irrigation. The landscape areas involved were 

estimated at 150 to 300 ac (60 to 120 ha). Treated, 

secondary, municipal effluent is piped to storage 

facilities and then applied to various reuse sites 

including golf courses, municipal parks, school yards, 

and some apartments or commercial real estate 

irrigated with sprinklers, and occasionally, drip 

systems. Irrigation was usually managed by regional 

estimates of consumptive use, and for golf courses, 

following real-time monitoring.

Water Quality Standards 

Municipal effluent in the study area is treated to meet 

“Public Access” reuse (Type I). The Texas regulation 

(TAC 210.33) for Type I use mandates biochemical 

oxygen demand, turbidity, fecal coliform (or E. coli), 

but not salinity. However, regulatory agencies or water 

providers can place additional stipulations for water 

quality goals. California guidelines, which are also the 

basis for the Food and Agriculture Organization (FAO) 

guidelines, outline hazard ranges, with no problems 

likely if salinity is less than 450 ppm, and increasing 

problems at 450 to 2000 ppm. The United States Golf 

Association (USGA) recommends a 1000 ppm limit for 

salinity, and a SAR limit of 6, except for special cases. 

Table 1 includes typical water quality data of 

reclaimed water in west Texas and southern New 

Mexico, along with observed landscape degradation. 

The quality of the reclaimed water varies temporally, 

and data may not reflect current quality; some samples 

in the study area exceeded the USGA guidelines for 

salinity.

Table 1 Reclaimed Water Quality in West Texas, Southern New Mexico with Landscape Degradation Issues

Water 

Sources

Water Quality

Soil Suborder Landscape Degradation

TDS

(ppm)

EC

(dS m1) SAR

Na

(ppm)

CI

(ppm)

El Paso

Rio Grande 660 0.9 3.2 110 92 Torrifluvents, Entisols Soil salinization

Fred Hervey 680 0.9 3.7 150 180 Calciorthid, Aridisols No problem (turf only)

Haskell 980 1.6 7.3 250 280 Torrifluvent, Entisols Leaf damage, salinization

Northwest 1200 2.2 11.0 350 325 Paleorthid, Aridisols Leaf damage, salinization

Alamogordo1 1800 2.7 2.0 310 480 Camborthid, Aridisols Leaf damage, salinization

Odessa2 1650 2.4 1.9 330 520 Paleustal, Alfisols Leaf damage 1 These water sources contain substantial quantities of Ca and SO4 2 Reclaimed water quality of this source changes with season

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Lessons Learned

In general, design of reclaimed water projects begin 

with the estimate of green areas with an assumption 

that all green areas can be irrigated with reclaimed 

water. This study has shown that this assumption may 

not be entirely valid for several reasons: 1) many 

landscape plants can be very sensitive to foliar salt 

adsorption caused by sprinkler application of water, 2) 

soil permeability can be too low to achieve necessary 

salt leaching to avoid buildup, and 3) difficulties of 

instituting policy changes necessary to reduce salinity 

and/or sodicity hazard.

Foliar-Induced Salt Damage. This problem is the 

most wide-spread. Plants adsorb salts through leaves 

when sprinkled, especially under high frequency 

irrigation. The extent of foliar damage is speciesdependent, and ranged from minor leaf-tip burn to 

premature defoliation, and plant mortality. Sensitive 

species, such as broad leaf trees can suffer leaf burn 

at 150 ppm of sodium or chloride in irrigation water. At 

250 ppm, nearly all species can be affected, except for 

pines and waxy leaf shrubs (Miyamoto and White, 

2002). Because of the widespread occurrence of this 

problem, site suitability assessments should include 

identification of species sensitive to overhead irrigation 

with water of elevated salinity (Miyamoto, 2006). An 

alternative is to convert sprinklers to low trajectory or 

under-canopy types. (Ornelas and Miyamoto, 2003).

Degradation through Soil Salinization. Landscape 

degradation caused by soil salinization depends on 

plant species (Miyamoto et al., 2004; Miyamoto, 2008). 

Soil salinization is also soil-type dependent and the 

most extensive soil salinization, was found in public 

sports fields developed on clayey Torrifluvents and 

irrigated with water from the Rio Grande. These soils 

do not have sufficient permeability to maintain a salt 

balance, especially when compacted. Some sports 

fields which were constructed at upland sites with 

topsoiling were also found to be salinized. The cause 

and process is still being studied. At the same time, 

little salt accumulation was found in golf courses 

developed on upland soils with high permeability, even 

when irrigated with water of nearly 2000 ppm total 

dissolved solids. Likewise, apartment and commercial 

building landscape developed on upland soils have 

shown no significant level of soil salinization, 

especially when the site is located on sloped 

topography which allows lateral salt leaching. 

Soil salinization can be minimized through subsoiling 

and soil profile modification (Miyamoto, 2008), and a 

change in construction protocols. However, there is a 

need to develop guidelines for soil improvements and 

design changes. Site suitability assessment must 

include identification of soil types prone to salinization.

Institutional Constraints. Methods of reducing 

salinity impact on landscape, such as proper plant 

selection, irrigation system alteration, and soil 

improvements are relatively easy to implement, except 

for upscale sports fields with many expensive features. 

However, voluntary implementation of these measures 

was not observed, especially at public facilities due 

significant changes in reuse expectations and policies. 

Site suitability assessments should include the 

evaluation of existing landscape codes and 

maintenance practices using potable water. Such 

information can provide indications of success 

potential when converting irrigation systems to 

reclaimed water. 

References

Miyamoto S. and A. Chacon, 2006. Soil salinity of urban turf 

areas irrigated with saline water: II. Soil factors. Landsc. & 

Urban Plan. 77(1-2):28-38.

Miyamoto S. 2008. Salt tolerance of landscape plants 

common to the southwest. Texas Water Resource Inst. TR316:1-37 May 2008. 

Miyamoto, S. 2006. Site suitability assessment for irrigating 

urban landscape with moderately saline water in the 

southwest. Presented at the 21st Annual WateReuse 

Symposium in Hollywood, CA on September 10, 2006.

Miyamoto, S. and J. White, 2002. Foliar Salt damage of 

landscape plants induced by sprinkler irrigation. Texas 

Water Resources Inst. TR-1202, March 2002. 

Miyamoto, S., I. Martinez, F. Luna and D. Tirre, 2008. 

Improving permeability and salt leaching in irrigated sports 

fields: Exploratory testing. Texas Water Resources Inst. TR310, February 2008. 

Miyamoto, S., I. Martinez, M. Padilla, A. Portillo and D. 

Ornelas, 2004. Landscape plan lists for salt tolerance 

assessment. Texas A&M Univ. Agr. Res. Cent. at El Paso, 

TX.

Ornelas, D., and S. Miyamoto, 2003. Sprinkler conversion to 

reduce foliar salt damage. Water Reuse Conference, San 

Antonio, TX.

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U.S. Water Recovery System on the 

International Space Station

Author: J. Torin McCoy (NASA Johnson Space Center)

US-TX-NASA

Project Background or Rationale 

International Space Station (ISS) crew members must 

conserve as much water as possible because each 

crew member is allocated only about two liters of water 

per day. Reclaimed spacecraft water (humidity 

condensate and urine distillate) was recognized as an 

efficient, innovative, and safe source for potable water 

for the ISS. The ability to recover water on ISS has 

allowed for habitation of six crew members and made 

the ISS less dependent on ground resupply.

In early phases of the ISS, astronauts relied on a 

Russian Mir system, in which atmospheric humidity 

condensate was collected and processed into potable 

water by a condensate water processor. NASA's water 

recovery system (WRS), launched to ISS in 2008, 

goes one step further: it recovers urine in addition to 

humidity. The system can recover about 85 percent of 

the water in urine. In order to accomplish this 

treatment goal, the process necessitated careful 

engineering and enhanced water quality monitoring 

and assessment. 

The WRS uses physical and 

chemical processes to remove 

contaminants from wastewater 

(Figure 1). The produced water 

is tested by onboard sensors; 

unacceptable water is cycled 

back through the water 

processor assembly. The 

reliability and safety of the 

system was demonstrated using 

a 90-day “checkout” on-orbit, 

during which no crew 

consumption of the reclaimed 

water was allowed. Monitoring 

during that timeframe showed 

that inflight chemical and 

microbial characteristics were 

similar to those observed in preflight system design and testing 

(Straub et al., 2010). U.S. crews 

have obtained approximately 75-100 percent of their 

potable water from this source, and have been able to 

store excess water for contingencies. Processing 

downtimes have been limited, and the WRS has 

proven reliable and efficient.

Microbial growth has been observed, but primarily only 

during periods of stagnancy. No pathogenic organisms 

have been detected and monitoring for non-pathogenic 

levels of microorganisms have been generally 

consistent with ground-based potable water systems in 

terms of concentrations and types of microorganisms. 

In addition to potable uses, other ISS systems (such 

as oxygen generation) successfully utilize reclaimed 

water.

Capacity and Treatment Technology

Under optimized conditions, the WRS will process 

approximately 7 liters of condensate daily, along with a 

similar volume of urine distillate. Approximately 12 

liters of potable water per day are reclaimed for 

potable purposes. As shown in Figure 1, recovered 

crew urine is distilled in the urine processor assembly 

Figure 1

WRS and Oxygen Generator Assembly (OGS) process flow diagram

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(UPA), and fed to the water processor assembly 

(WPA) along with humidity condensate/wastewater; 

these elements together constitute the U.S. water 

recovery system (WRS), as shown in Figure 2. 

Reclaimed water is used by the crew as a potable 

source, and is fed to the oxygen generation assembly 

(OGA) as a source of electrolytic oxygen that is 

returned to the spacecraft cabin.

Project Funding and Management 

Practices 

The ISS had substantial investments in the 

implementation of the WRS. Costs for launching water 

are approximately $10,000/lb ($50,000/liter) because 

of the relatively large weight of water necessary to 

support six crew members on ISS (~25 lbs/day or 11.3 

kg/day), which makes a strong rationale for use of 

reclaimed water. Recycling water also serves to 

reduce crew dependency of resupply. Management 

was also interested in proving technologies such as 

WRS that represented skills/resources needed for 

more remote spaceflight missions.

Institutional and Cultural 

Considerations 

Given the unique setting and end users, there were 

not significant objections to implementation of WRS on 

ISS. However, there were indeed stigmas regarding 

the reclaimed water use (especially in regard to urine 

recycling). Those stigmas were overcome through 

openness and effective communication with 

stakeholders. “Taste tests” and other forums were 

used to encourage acceptance among crew and

decision-makers.

Successes and Lessons Learned

WRS has operated successfully since 2008, and 

serves as a model for implementation of complex and 

innovative hardware in a remote environment. Lessons 

learned have included the value of proper planning, 

the need for continued monitoring, and the 

challenges/strengths of multi-disciplinary collaboration.

References

Bagdigian, R., L. Carter, and G. Sitler. “Status of the 

Regenerative ECLSS Water Recovery System.” International 

Conference of Environmental Systems (ICES) Proceedings, 

2008. AIAA Paper 2008-01-2133. SAE. 

Straub, J., D. Plumlee, and J. Schultz. “ISS Expeditions 16-

20: Chemical Analysis Results for Potable Water.”

International Conference of Environmental Systems (ICES) 

Proceedings, 2010. Paper AIAA 2010-6042. SAE. 

Figure 2

Water recovery system on ISS

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East Fork Raw Water Supply Project: 

A Natural Treatment System Success Story

Authors: Ellen T. McDonald, PhD, P.E. and Alan H. Plummer, Jr., P.E., BCEE (Alan 

Plummer Associates Inc.) and

James M. Parks, P.E. (North Texas Municipal Water District) 

US-TX-Wetlands

Project Background or Rationale 

North Texas Municipal Water District (NTMWD) 

currently provides potable water to a population of 

over 1.6 million in a region north and east of the City of 

Dallas. Water is diverted for treatment from the 

NTMWD's primary raw water supply reservoir, Lavon 

Lake, which is located in the Trinity River basin and 

has a firm yield of approximately 104,000 acre-feet per 

year (~93 mgd). This supply is supplemented with 

transfers to Lavon Lake from two other water supply 

reservoirs, one located in the Red River basin and one 

in the Sulphur River basin. In addition to its potable 

water supply facilities, NTMWD owns and operates 4 

regional wastewater treatment plants and operates 12 

smaller wastewater treatment plants within its service 

area. 

NTMWD is located in one of the fastest growing 

regions in the United States. By 2020, the service area 

population is anticipated to grow by nearly 700,000 

and more than double in the next 50 years. As a result 

of this unprecedented growth and a strong 

commitment to the efficient use of water resources, 

NTMWD developed the East Fork Raw Water Supply 

Project (EFRWSP) in order to further augment water 

supply in Lavon Lake.

The EFRWSP diverts return flows from the East Fork 

of the Trinity River, contributed by NTMWD-owned or 

customer-owned wastewater treatment facilities, and 

conveys the return flows through a constructed 

wetland prior to delivery to Lavon Lake. The project, 

when developed at full capacity, will add 91 mgd of 

raw water supply to Lake Lavon for subsequent 

treatment and use by NTMWD customers. 

Capacity and Type of Reuse 

Application 

The wetland covers 1,840 acres and is designed to 

remove sediments and nutrients from the water, where 

it is retained for 7-10 days prior to delivery to Lavon 

Lake. Work on the wetland began in 2004 with the 

design and construction of the first of two nursery 

wetlands. The initial nursery, 25 acres in size, was 

used to provide plant stock of selected emergent 

wetland species for a 180-acre second phase nursery. 

The 180-acre nursery was completed in 2006 and was 

used to provide over 1.6 million plants for the full-scale 

wetland (Figure 1).

The general layout of the wetland is shown in 

Figure 2. The diversion pump station includes a river 

diversion structure and 165 mgd pump station which is

used to divert flow from the East Fork Trinity River to 

the upstream end of the wetland. Currently this pump 

station includes two 250 horsepower (hp), 16,810 

gallon per minute (gpm) and two 500 hp, 33,620 gpm 

vertical turbine pumps. Space has been provided for 

one additional pump. The conveyance pump station 

also has a capacity of 165 mgd, and currently includes 

three 3,000 horsepower, 33,620 gpm vertical turbine 

pumps used to convey the wetland-polished water to 

Lavon Lake. Space for two additional pumps has been 

provided.

Figure 1

ERWSP wetland, May 2009 (Photo credit: Alan 

Plummer Associates, Inc.)

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Water enters at the north end and travels through 

sedimentation basins prior to entering the main cells. 

The wetland includes parallel trains with multiple cells. 

There are three distinct geographic zones; the wetland 

trains in each zone discharge to a common channel or 

pool where outflows from each individual train 

commingle. The flow is subsequently redistributed to 

the uppermost cells of the trains in the next zone. In 

effect, this arrangement creates three distinct 

treatment wetlands which present some design 

challenges, but provide additional operational 

flexibility. Deep water zones were included at the inlet 

and outlet of each cell. Intermediate deep water zones 

were also included to help redistribute flow across the 

cells should preferential flows or short circuiting 

develop.

Water Quality Standards and 

Treatment Technology 

Water quality within Lavon Lake was a key 

consideration during planning of the project. One of 

the imported supplies originates from a relatively high 

total dissolved solids (TDS) source. Furthermore, in 

addition to the imported supplies, the NTMWD's 

largest regional wastewater treatment plant (currently 

permitted at a capacity of 48 mgd) discharges into the 

western arm of Lavon Lake. Thus, the assimilative 

capacity of the lake as it relates to dissolved solids, 

nutrients and eutrophication, as well as potential 

impacts of microconstituents were addressed within 

the planning process.

Project Funding and Management 

Practices 

The wetland was developed through a partnership with 

the Carolyn Hunt Trust Estate, which owns and 

operates a ranch and a smaller wetland on the 

property. This partnership has resulted in the 

construction of the largest water supply project of its 

kind in the United States.

Water rights permitting was also a key component of 

the EFRWSP planning process. Return flows from the 

Dallas-Fort Worth Metroplex travel down the Trinity 

River, ultimately reaching Lake Livingston, which is a 

major water supply reservoir serving the city of 

Houston. In addition, several of the NTMWD 

wastewater treatment plants supplying the EFRWSP 

discharge into an upstream reservoir owned by the 

City of Dallas. Furthermore, several environmental 

interest groups expressed concerns about potential 

decreases in freshwater inflows to Galveston Bay, 

located downstream of Lake Livingston. Securing the 

water right for the project required a lengthy 

negotiation process with all of these parties.

Institutional/Cultural Considerations 

As indicated above, water rights in a water-short state 

raised significant discussions. By working together 

over several years, parties came to agreement, 

including several environmental interest groups initially 

concerned with Instream flows and cumulative flows to 

the Texas bays and estuaries. Through education and 

negotiations to limit internal Lavon Lake blending to 30 

percent, these interest groups recognized the inherent 

environmental benefits of potential deferral of the need 

to construct new water supply reservoirs and the 

development of additional aquatic life habitat created 

by the wetland.

The wetland and nature center was developed through 

a partnership with the Carolyn Hunt Trust Estate, 

which owns and operates a ranch and a smaller 

wetland on the property. The project has experienced 

very little public opposition, and overall is seen as an 

asset to area by environmental interest groups, the 

water supply community and the general public. This 

positive image is largely attributed to the constructed 

wetland, which provides multiple benefits associated 

Figure 2

ERWSP Flow Directions

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with water supply, aquatic life habitat enhancement, 

and extensive educational and research opportunities. 

Successes and Lessons Learned

The EFRWSP is operational and providing immediate 

benefit to area water supply customers and the public. 

Time educating and negotiating differing opinions has 

resulted in a project with benefits for all interested 

parties.

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2012 Guidelines for Water Reuse

Potable Water Reuse in the Occoquan Watershed

Authors: Robert W. Angelotti (Upper Occoquan Service Authority)

and Thomas J. Grizzard, PhD, P.E. (Virginia Tech)

US-VA-Occoquan

Project Background or Rationale 

The Occoquan Reservoir is a critical component of the 

water supply for approximately 1.5 million residents of 

Northern Virginia, a highly urbanized region located 

west of Washington, D.C. (Figure 1). Reclaimed water 

represents a significant supplement to potable water 

supply yield from the reservoir and has been 

successfully augmenting the drinking water supply for 

over three decades.

Rapid transformation from a largely rural to a 

predominantly urban/suburban region began in the 

1960s as a result of unprecedented growth from the 

westward expansion of the urban core of Washington, 

D.C. By the mid-1960s, this urbanization was 

adversely affecting water quality of the Occoquan 

Reservoir, resulting in an unplanned and unintended 

indirect potable reuse scenario, where 11 small 

wastewater treatment plants were discharging effluent 

upstream of the reservoir. Poorly treated wastewater, 

with urban and agricultural runoff, threatened 

continued use of the Occoquan Reservoir for public 

water supply.

In 1971, the Virginia State Water Control Board 

(VDEQ) and the Virginia Department of Health (VDH) 

adopted a plan to protect the Occoquan Reservoir as a 

drinking water supply. The Occoquan Policy mandated 

a newly conceived framework for water reuse and set 

in motion the first planned and intentional use of 

reclaimed water for supplementing a potable surface 

water supply in the United States (VDEQ and VDH, 

2012). 

The Occoquan Policy mandated creation of a regional 

State authority, the Upper Occoquan Service Authority 

(UOSA), to provide collection and reclamation of 

wastewater, and the Occoquan Watershed Monitoring 

Program (OWMP), to continuously monitor the 

watershed and reservoir to provide independent water 

quality assessments and advice on protective 

measures for the reservoir. By the 1970s, Fairfax 

Water was responsible for potable water production 

and distribution for much of Northern Virginia. The 

VDEQ and VDH were also highly involved in 

developing the ultimate solution.

While water quality improvement was the primary 

driver for implementing planned and intentional 

potable water reuse in the Occoquan system, 

supplementing the raw water supply was always an 

underlying objective. Although the mid-Atlantic region 

of the U.S. is not considered dry or arid, the population 

density results in stressed water supply, and limited 

per capita water availability. This situation becomes 

more pronounced during periodic extended drought 

conditions. 

Capacity and Type of Reuse 

Application 

A diagram illustrating how the UOSA reclamation 

system interacts with the drinking water supply is 

provided in Figure 2. The UOSA reclamation plant 

produces about 32 mgd (1,400 L/s) of water on an 

annual average basis and the plant has the capacity to 

reclaim as much as 54 mgd (2,370 L/s) of water. A 

future annual average plant flow of around 65 mgd is 

Figure 1

Aerial view of the Occoquan Reservoir (Photo credit: 

Roger Snyder, Manassas, Virginia)

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associated with the build out condition within the 

UOSA service area. Future reclaimed water production 

is anticipated to effectively double the safe yield of the 

Occoquan Reservoir. Although the majority of water 

produced supplements the drinking water supply, 1 to 

3 mgd (44 to 130 L/s) is also delivered for nonpotable 

uses on the UOSA campus.

Water Quality Standards and 

Treatment Technology 

The water reclamation process includes preliminary 

and primary treatment followed by complete mixed 

activated sludge with biological nitrogen removal. 

Advanced water treatment processes include lime 

precipitation and two stage recarbonation with 

intermediate settling; these processes remove 

phosphorus and are barriers to pathogens and heavy 

metals. Final polishing is accomplished with 

multimedia filtration, granular activated carbon 

adsorption, chlorination and dechlorination. 

Reclaimed water is produced at concentrations that 

meet all Federal Primary and Secondary Drinking 

Water Standards except occasionally for nitrate and 

total dissolved solids. Seasonally, the nitrate drinking 

water standard is exceeded purposefully to accomplish 

specific reservoir water quality goals. Reclaimed water 

quality permit standards are provided in the UOSA 

discharge permit (UOSA and VDEQ, 2012), and 

typical characteristics of the reclaimed water are 

available from UOSA (UOSA, 2012). 

Management Practices and 

Institutional Considerations 

Today, the concept of indirect potable reuse is well 

communicated to regulators and public official 

stakeholders within the region. Interested parties 

within local municipalities are well aware that a 

significant portion of the water supply is comprised of 

reclaimed water. Both Fairfax Water and UOSA are 

run by a board of directors. Board members are 

representatives for their community and make 

Figure 2

The UOSA Reclamation Plant provides an important source of water for the service area (Photo credit: 

CDM Smith for UOSA)

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decisions in the best interest of the communities they 

serve. It is not uncommon for UOSA to collaborate 

closely with representatives of local governments 

about issues relating to water quality. 

The community and the independent water quality 

monitoring entity, OWMP, both openly acknowledge 

that the reclaimed water produced by UOSA is the 

most reliable and highest quality water entering the 

Occoquan Reservoir. The OWMP has a technical 

advisory panel that is comprised of members from 

EPA, VDEQ, VDH, and an expert from an accredited 

and well-renowned academic institution within the 

state (Virginia Polytechnic Institute and State 

University, otherwise known as Virginia Tech). This 

provides even greater confidence and credence for 

potable reuse in the region. 

Periodically, water related issues within the region 

result in the formation of technical advisory groups, 

citizen action committees and task forces. These may 

be composed of agency stakeholders, city or county 

government officials, community representatives, 

water experts and interested citizens. Examples of 

issues tackled by such groups include: land zoning 

around the reservoir to protect water quality, siting of a 

major semiconductor industry within the UOSA service 

area, and consumptive use of reclaimed water by a 

proposed power plant. These collaborative efforts with 

interested and affected parties are used to gather input 

before important decisions are made that might impact 

water quality or its availability to users.

Cultural and Social Considerations

When water reclamation was first proposed, a number 

of hearings were conducted to explain what was to be 

implemented and to provide the public a venue to 

express their views. UOSA has always engaged in an 

active program to provide tours to local students, from 

grade school through college, during which potable 

reuse is thoroughly explained. These tours have been 

conducted for more than 30 years, providing public 

outreach to the local population on the importance of 

UOSA’s mission. In addition, UOSA maintains a public 

website where it’s role in potable water reuse is clearly 

expressed. UOSA’s success has not required 

dedicated public relations staff or a formal public 

outreach and communication program.

Successes and Lessons Learned

Perhaps the greatest key to success of this project is 

that it was implemented specifically to improve water

quality problems in the existing surface water reservoir 

being used as the drinking water supply. The project 

was initiated by the Commonwealth of Virginia, via 

state regulation (the Occoquan Policy) which was 

developed by the VDEQ and VDH. Early water quality 

problems in the Occoquan Reservoir were clearly 

articulated and the best solution for the region was 

presented to stakeholders and interested citizens. 

Although water quality was the major driver, it was 

clearly recognized that treated wastewater flows 

returned to the reservoir would be a significant and 

valuable resource in the future. 

This project is unique in that there is a separate 

watershed management program (OWMP), along with 

its associated water quality monitoring laboratory 

(OWML) that provides oversight, independent 

accountability and recommendations to the water 

reclamation agent (UOSA), the potable water 

treatment and distribution entity (Fairfax Water) and 

state regulatory agencies. This was critical in 

establishing a credible voice of endorsement and 

recommendation for the plan. Collaboration among 

major institutional entities that work toward common 

goals of protecting and improving the water quality of 

the reservoir demonstrates the leadership for waterrelated issues for the community. More than 34 years 

of successful implementation has demonstrated 

confidence that the original plan is still working well 

today.

References

Upper Occoquan Service Authority (UOSA), 2012. Typical 

Water Product Quality. typical performance characteristics. 

Retrieved July 27, 2012 from 

<http://uosa.org/Information/Water Product Quality>. 

Upper Occoquan Service Authority (UOSA) and Virginia 

Department of Environmental Quality (VDEQ). 2012. 

Authorization to Discharge Under the Virginia Pollutant 

Discharge Elimination System and the Virginia State Water 

Control Law. Retrieved July 27, 2012 from 

<http://uosa.org/Information/VPDES Permit>. 

Virginia Department of Environmental Quality (VDEQ) and 

Virginia Department of Health (VDH), 2012. Occoquan 

Watershed water reuse policy. Retrieved July 27, 2012 from

<http://lis.virginia.gov/cgibin/legp604.exe?000+reg+9VAC25-410-10>.

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Water Reuse Policy and Regulation in Virginia

Author: Valerie Rourke, CPSS, LPSS, CNMP (Virginia Department of 

Environmental Quality)

US-VA-Regulation

Project Background

The Commonwealth of Virginia has had a long history 

of water reuse, which formally began with the 

operation of an indirect potable reuse project by the 

Upper Occoquan Sewage Authority (now the Upper 

Occoquan Service Authority) (UOSA) in 1978 [US-VAOccoquan]. Consistent with national trends, water 

reuse has continued to gain greater acceptance and 

application in Virginia due primarily to efforts to reduce 

or avoid wastewater treatment facility discharges to 

surface waters, and increasing urban population 

growth. 

EPA has developed a total maximum daily load 

(TMDL) for nutrients that are discharged to the 

Chesapeake Bay. The TMDL affects all point source 

discharges of states, including Virginia, within the 

watershed of the Chesapeake Bay. As a result, 

Virginia’s discharging wastewater treatment facilities 

are required to meet lower nutrient limits through 

nutrient trading1

From 1950 to 2010, Virginia’s population more than 

doubled from 3.2 million to 8.0 million inhabitants with 

an increase of 13 percent during the period of 2000 to 

2010. Projected population growth will be in mostly 

urban centers of the state. Although Virginia has an 

average annual rainfall of 40 inches, it experiences 

water shortages during periods of prolonged drought. 

Such water shortages are compounded by population 

growth, which places an increasing demand on water 

, the installation of nutrient removal 

technology or the implementation of non-discharging 

alternatives, such as water reuse.

 

1 Nutrient trading is a market-based program that provides 

incentives for entities to create nutrient reduction credits by going 

beyond statutory, regulatory or voluntary obligations and goals to 

remove nutrients from a watershed. To achieve a desired load 

reduction, trades of nutrient credits can take place between point 

sources (usually wastewater treatment plants), between point and 

nonpoint sources (a wastewater treatment plant and a farming 

operation) or between nonpoint sources (such as agriculture and 

urban stormwater sites or systems).

supply. As a result, Virginia’s Local and Regional 

Water Supply Planning Regulations (9VAC25-780) now 

require localities to develop water plans to ensure the 

availability of adequate and safe drinking water for 

citizens of the Commonwealth, and to protect all other 

beneficial uses of the Commonwealth’s water 

resources. As part of their water plan, localities must 

provide a statement of water need and alternatives to 

meet this need; alternatives may include nontraditional 

options, such as inter-connection, desalination, 

recycling and reuse. 

Current Regulations and Guidelines 

Virginia does not have a singular, comprehensive 

policy or program for reuse of all types of water that 

have historically been wasted or disposed. Rather, 

multiple state agencies have regulations or guidelines 

that affect water reuse, determined in most cases by 

the type of wastewater to be reclaimed, with some 

degree of redundancy. For example, the following 

agencies have regulations or guidelines governing 

aspects of water reuse:

 The Virginia Department of Environmental 

Quality (DEQ) has regulations for the 

reclamation and reuse of domestic, municipal or 

industrial wastewater collected and treated 

through centralized systems.

 The Virginia Department of Health has regulations that allow the onsite treatment and reuse 

of sewage for toilet flushing in conjunction with a 

permitted onsite sewage system, and has 

guidelines for the non-potable use and reuse of 

harvested rainwater and graywater, respectively.

 The Virginia Department of Housing and 

Community Development has regulations for the 

indoor treatment and plumbing of recycled gray 

water and harvested rainwater, and for the 

indoor plumbing of reclaimed water meeting 

appropriate regulatory standards administered 

by the DEQ for indoor reuses.

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 The Virginia Department of Conservation and 

Recreation has limited regulations for the 

reclamation and reuse of storm water and 

evaluates such proposals on a case-by-case 

basis.

History and Regulation Development 

Virginia’s process to adopt regulations for the 

reclamation and reuse of domestic, municipal and 

industrial wastewater first began in 1999. The Virginia 

General Assembly directed DEQ to convene a 

committee to assist the agency with the development 

of a report (House Document No. 92), examining the 

advantages and disadvantages of water reuse as the 

basis for future legislation on this subject. In 2000, the 

General Assembly incorporated some of the 

recommendations of the report into the Code of 

Virginia, providing the statutory basis for the State 

Water Control Board to develop regulations for water 

reuse. Following two separate consecutive actions to 

develop such regulations, the Virginia Water 

Reclamation and Reuse Regulation (9VAC25-740) was 

adopted and became effective on October 1, 2008.

The Water Reclamation and Reuse Regulation is 

unique among other water regulations adopted by the 

State Water Control Board (SWCB). Most water 

regulations of the SWCB fall distinctly within policy, 

permitting, standards or technical categories. The 

Water Reclamation and Reuse Regulation (9VAC25-

740) however, contains standards for reclaimed water 

and provides technical design and operational 

requirements for facilities that produce, store and 

distribute reclaimed water for reuse. It is not a permit 

regulation but, describes existing water permit types 

that may be used to authorize water reclamation and 

reuse projects. It is also a “bridging” regulation for 

projects that have both wastewater treatment and 

water resources or supply components, such as for 

indirect potable reuse.

The development or amendment of any regulation 

adopted by the SWCB must follow the procedures 

described in the Administrative Process (Act §2.2-4000 

et seq. of the Code of Virginia). The SWCB typically 

delegates its authority to develop and implement 

regulations to the DEQ. In accordance with agency’s 

Public Participation Guidelines (9VAC15-11), the DEQ 

may assemble a regulatory advisory panel or a 

technical advisory committee to assist the agency with 

the development of a regulation. DEQ assembled a 

technical advisory committee for the Water 

Reclamation and Reuse Regulation, which provided 

significant input and support during this process. 

Resources Used to Develop the 

Regulations 

To develop the Water Reclamation and Reuse 

Regulations, DEQ relied upon and benefitted from a 

variety of existing resources. These included the EPA 

Guidelines for Water Reuse (2004); rules, regulations, 

guidelines and regulatory contacts of water reuse 

programs in other states; the WateReuse Association; 

and WateReuse Symposiums. The EPA Guidelines for 

Water Reuse provided a preliminary framework and 

basic items that should be considered as part of any 

regulatory program for water reuse. Other states’ 

water reuse rules, regulations and guidelines provided 

information about more detailed items to consider as 

part of a regulatory program. Discussions with other 

water reuse regulators, particularly through the 

WateReuse Association or at the annual WateReuse 

Symposium, were invaluable regarding unique 

problems and solutions, and the implementation of a 

water reuse program. 

Media Involvement 

The media was involved to occasionally cover the 

status of the regulation during development and 

eventual adoption.

Institutional/Cultural Considerations 

There were no institutional or cultural issues that drove 

decisions during the development of the regulation.

Details Particular to Virginia 

Water reclamation and reuse is strictly voluntary in 

Virginia. However, when a facility chooses to reclaim 

domestic, municipal or industrial wastewater for reuse, 

the facilities must comply with the requirements of the 

Water Reclamation and Reuse Regulation with some 

exceptions as described in 9VAC25-740-50. Treatment 

requirements and reclaimed water standards in the 

regulation were developed to be protective of public 

health and the environment, while providing options 

that, to the greatest extent possible, would allow most 

existing wastewater treatment facilities to produce 

reclaimed water with little or no change in their 

treatment processes. Less treatment, however, will 

limit reuse options in most cases. Indirect potable 

reuse projects may be permitted on a case-by-case 

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basis but, direct potable reuse is prohibited. The Water 

Reclamation and Reuse Regulation specifically 

excludes graywater reuse and does not address the 

reclamation and reuse of storm water or harvested 

rainwater, which are addressed by the guidelines or 

regulations of other state agencies.

Unlike the water reuse rules, regulations and 

guidelines of other states, the Virginia Water 

Reclamation and Reuse Regulation requires that all 

irrigation with reclaimed water be supplemental. 

Supplemental irrigation is defined as irrigation, which 

in combination with rainfall, meets but does not exceed 

the water necessary to maximize production or 

optimize growth of the irrigated vegetation. This 

definition is intended to distinguish land treatment of 

wastewater, a method of disposal, from irrigation reuse 

that involves irrigation of crops for a beneficial use 

rather than disposal. Due to this difference, land 

treatment will generally require ground water 

monitoring, while irrigation reuse will not. Also, 

irrigation reuse may be either bulk or non-bulk 

determined by the size of the irrigation site. For bulk 

irrigation reuse of reclaimed water (irrigation of areas 

greater than five acres on one contiguous property), a 

nutrient management plan will be required where nonbiological nutrient removal (non-BNR) reclaimed water 

(reclaimed water with annual average concentrations 

of total nitrogen and total phosphorus greater than 8 

and 1.0 mg/l, respectively) will be applied to the 

irrigation reuse sites. Irrigation of non-bulk irrigation 

sites with non-BNR reclaimed water will not require a 

nutrient management plan but will be required to 

implement other measures to manage nutrients at the 

irrigation reuse site.

Successes and Lessons Learned

While water reclamation and reuse poses some 

unique issues in Virginia, it is still viewed as a useful 

tool among others to optimize water resources long 

term. It is shifting the paradigm from one that has 

viewed water resources and wastewater treatment 

separately, to one that views water resources and 

wastewater treatment as related and affecting each 

other.

References

§ 2.2-4000 et seq., Administrative Process Act.

9 VAC 15-11-10 et seq., Virginia Administrative Code, Public 

Participation Guidelines.

9 VAC 25-740-10 et seq., Virginia Administrative Code, 

Water Reclamation and Reuse Regulation.

9 VAC 25-780-10 et seq., Virginia Administrative Code, 

Local and Regional Water Supply Planning Regulations.

Report of the Virginia Department of Environmental Quality: 

Land Application, Reclamation and Reuse of Wastewater to 

the Governor and General Assembly of Virginia, House 

Document No. 92, DEQ, 2000.

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2012 Guidelines for Water Reuse

City of Sequim's Expanded Water Reclamation Facility and 

Upland Reuse System

Author: Chad Newton, P.E. (Gray & Osborne, Inc.)

US-WA-Sequim

Project Background or Rationale 

The city of Sequim is a community on the Olympic 

Peninsula in Washington State, along the Strait of 

Juan de Fuca and adjacent to the Dungeness River. 

Sequim is a rapidly growing community in part 

because, unlike the rest of the peninsula, Sequim has 

a dry climate and averages 15 inches of rainfall per 

year due to the storm-blocking effect of the Olympic 

Mountains. Adjacent to Sequim are marine waters with 

major shellfish harvesting areas for Dungeness crab, 

oysters, geoducks, and clams.

The city constructed the first wastewater treatment 

facilities at the current site in 1966 with a marine outfall 

into the Strait of Juan de Fuca. In 1994, following 

several years of contention over deteriorating surface 

water quality, shellfish restrictions and insufficient 

water supply, the city of Sequim signed an agreement 

with two state agencies to develop a plan for upland 

reuse of their wastewater. The 1998 Class “A” 

Reclaimed Water 100 Percent Upland Reuse Plan 

included three primary water reuse sites.

Development of Water Reclamation 

Facility 

In 1998, parallel to the water reuse plan, the city 

upgraded its wastewater treatment facility into a 0.79 

mgd (35 L/s) Class A Water Reclamation Facility 

(WRF). Class A is the highest quality class of 

reclaimed water in Washington State’s reuse 

guidelines and must be continuously oxidized, 

coagulated, filtered and disinfected. The project 

upgraded the existing processes, including influent 

screening, grit removal, activated sludge treatment in 

an oxidation ditch, secondary clarification and aerobic 

sludge digestion. The project also added chemical 

coagulation, anthracite media filtration and lowpressure/low-intensity UV disinfection to produce 

reclaimed water. The effluent quality requirements at 

the Sequim WRF are summarized in Table 1. The 

facility is equipped with a bypass holding pond for 

diversion of inadequately treated wastewater if online 

monitoring indicates that reclaimed water does not 

meet permit requirements.

Table 1 Reclaimed Water Quality Requirements

Parameter

Effluent Limit

Monthly 

Average

Weekly 

Average

BOD5 (mg/L) 30 45

TSS (mg/L) 30 45

D.O. (mg/L) Must be present

Filtration Monthly 

Average

Sample 

Maximum

Turbidity (NTU) 2 5

Disinfection 7-Day 

Median

Sample 

Maximum

Total Coliform (MPN/ 

100 mL)

<2.2 23

Nitrogen Removal Monthly 

Average

Daily Maximum

Ammonia (mg/L) 3.3 5.7

Total Nitrogen (mg/L) 10 N/A

Following construction of the WRF and the water 

reuse sites, the Washington State Department of 

Health opened 2,800 acres of previously closed 

shellfish beds for harvesting, retaining only a 300-foot 

radius closure around the outfall.

Water Reuse System

The city has developed a reclaimed water distribution 

system that seasonally diverts a large portion of the 

reclaimed water away from the marine outfall. 

Reclaimed water is conveyed from the WRF to the 

reuse sites for the following uses:

 Reuse Demonstration Site at Carrie Blake Park, 

where reclaimed water is used for park 

irrigation, toilet-flushing and, following reaeration, stream flow augmentation to Bell 

Creek (Figure 1) to improve stream flows for 

fisheries and habitat restoration.

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2012 Guidelines for Water Reuse

 Highway 101 Bypass future rest stop, planned 

landscape irrigation system (rest stop and 

irrigation system have not yet been 

constructed). 

 The City Shop, where reclaimed water is used 

for vehicle washing, street cleaning and fire 

truck water, and made available to the public for 

construction purposes such as dust control. 

 Landscape irrigation of street medians.

WRF Expansion Project 

In 2007, due to rapid population growth in the region, 

the city expanded the WRF, doubling capacity and 

converting the WRF from an oxidation ditch to a 

conventional activated sludge plant employing the 

Modified Ludzack-Ettinger (MLE) process for 

enhanced nitrogen removal. Construction of the 

expansion project began in August 2008 and was 

completed September 2010 at a project cost of $11 

million.

The reclaimed water permit for the expanded WRF is 

not yet finalized, but is anticipated to retain the effluent 

quality limitations in Table 1. The 2008-10 WRF 

expansion project included:

 Conversion of the existing equalization basin 

(EQB) into a plug-flow activated sludge basin 

(MLE process with nitrogen removal)

 Conversion of the existing oxidation ditch into 

an EQB

 Addition of a third secondary clarifier

 Addition of a fabric filter to increase the filtration 

capacity of the existing anthracite media filter

The WRF expansion (Figure 2) project also included 

redundant aeration blowers with a dissolved oxygen 

control system, additional coagulation equipment, and 

a remote alarm system. Electric power for the entire 

treatment process is backed up by generators. For the 

protection of public health and the environment 

(including shellfish beds), expansion of the disinfection 

system was designed to meet the pathogen removal 

criteria developed by the National Water Research 

Institute (NWRI) to produce essentially pathogen free 

reclaimed water. 

Water Reuse System Expansion 

Project 

In 2008, the city began an effort to identify additional 

uses of reclaimed water in order to reduce the volume 

discharged to the Strait of Juan de Fuca, and reduce 

demands on the Dungeness River aquifer for irrigation 

and potable water. The city received a grant from the 

Washington State Department of Ecology for planning 

and design of a water reuse system expansion. 

A study identified potential new uses including 

groundwater recharge and additional irrigation areas. 

Five sites were studied for groundwater infiltration 

basins, which would allow year-round augmentation of 

the shallow aquifer with reclaimed water and 

significantly reduce marine outfall discharge outside 

Figure 2

Sequim Water Reclamation Facility expansion (Photo 

credit: Gray & Osborne, Inc.)

Figure 1

Introduction of reclaimed water to Bell Creek (Photo 

credit: Gray & Osborne, Inc.)

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2012 Guidelines for Water Reuse

the irrigation season. The 2008-10 WRF Expansion 

project provided reclaimed water with nitrogen levels 

suitable for groundwater recharge. Hydrogeological 

studies were performed at two of the sites in 2010, 

including monitoring well studies with pilot infiltration 

pits.

In 2011, an engineering plan was completed for the 

water reuse system expansion, which recommends 

the following improvements:

 Construction of 1.3 ac (0.53 ha) of rapid 

infiltration basins at the Reuse Demonstration 

Site, with an estimated capacity of 1.3 mgd 

(57 L/s).

 Construction of a booster pump station and 

reservoir to provide reclaimed water to the city’s 

high pressure zone, for irrigation uses.

 Expansion of the distribution system to provide 

access to reclaimed water to additional irrigation 

users.

 Construction of additional reclaimed water 

storage at the WRF and the Reuse 

Demonstration Site.

 Conduct a pilot project of groundwater recharge 

at the City Shop property. If successful, 

reclaimed water could be applied to shallow 

groundwater throughout the reclaimed water 

pipeline system.

The city plans to implement the design and construct 

the water reuse system expansion projects as funds 

become available.

Results and Conclusion 

In the mid-1990s, following several years of contention 

over deteriorating surface water quality, shellfish 

restrictions and insufficient water supply, the city of 

Sequim embarked on a water reuse program by 

upgrading their existing wastewater treatment plant 

into a “Class A” water reclamation facility and 

developing a reclaimed water distribution system and 

reuse sites. However, irrigation was the primary use 

for reclaimed water and the marine outfall was still 

needed, especially during the non-irrigation season. 

Ten years later, as the population continued to grow 

and the reclaimed water system matured, the city has 

expanded the WRF treatment capacity and is planning 

for a significant expansion of water reuse capacity.

The water reuse program at the city of Sequim has 

been successful since 2000 when 2,800 ac (1,130 ha) 

of previously closed shellfish beds were reopened for 

harvesting. Due to the upgrades in reliability and 

pathogen removal provided by the 2008-10 WRF 

expansion, the Washington State Department of 

Health concluded that the existing shellfish closure 

zone, a 300-yard (274-m) radius around the marine 

outfall, would not require enlargement, despite a 

doubling of flow capacity.

Due to the parallel efforts of the city to expand the 

WRF and develop additional reuse facilities, the city 

will experience improvements in fish and wildlife 

habitat and a reduction in the amount of reclaimed 

water sent through the marine outfall, and, eventually, 

achieve the goal of the 1998 “Class A” Reclaimed 

Water 100 Percent Upland Reuse Plan.

References

CH2M Hill, 1998. Operation and Maintenance Manual: City 

of Sequim Wastewater Treatment Plant Reclamation 

Facilities. CH2M Hill, Bellevue, Washington.

Gray & Osborne, Inc., 1998. Class “A” Reclaimed Water 

100 Percent Upland Reuse Plan, Amendment to the 

Comprehensive Wastewater Facilities Plan. Gray & 

Osborne, Inc., Seattle, Washington.

Gray & Osborne, Inc., 2007. Water Reclamation Facility 

Expansion Engineering Report. Gray & Osborne, Inc., 

Seattle, Washington.

National Water Research Institute, 2003. Ultraviolet 

Disinfection: Guidelines for Drinking Water and Water 

Reuse. National Water Research Institute, Fountain Valley, 

California.

Washington State Department of Ecology and Washington 

State Department of Health, 1997. Water Reclamation and 

Reuse Standards, Publication #97-23. Washington State 

Department of Ecology and Washington State Department of 

Health, Olympia, Washington.

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2012 Guidelines for Water Reuse

Washington State Regulations

Authors: Chad Newton, P.E. (Gray and Osborne, Inc.)

and Craig Riley, P.E. (Washington State Department of Health)

US-WA-Regulations

Project Background

Washington State has a reclaimed water program 

governed by comprehensive guidelines that define 

water quality standards and a variety of allowed 

beneficial uses. At the time of this publication, there 

are at least 25 water reclamation systems in operation 

or are in the process of being permitted in the state. 

In 1992, Washington State initiated the Reclaimed 

Water Law, Revised Code of Washington (RCW) 

90.46 after a prolonged drought. In 1995, the 

legislature declared that reclaimed water was no 

longer wastewater. In 1997 the Washington State 

guidelines, Water Reclamation and Reuse Standards

were adopted, directing the State Departments of 

Ecology and Health to jointly administer the reclaimed 

water program (Washington State Department of 

Ecology and Washington State Department of Health, 

1997). This created a framework to tap an unused 

water resource while assuring public health protection 

and environmental stewardship. 

In 2006, the Department of Ecology began developing 

a Reclaimed Water Rule, a state regulation that would 

supersede the existing guidelines. The current draft of 

the regulation (Washington State Department of 

Ecology, 2010) was made available to the public in 

May 2010, and refers to a Reclaimed Water Facilities 

Manual for supplemental guidance on implementing 

the rule. The guidance manual is currently under 

development. Legislative amendments have been 

proposed to consolidate all regulatory duties at 

Department of Ecology, and to authorize fees to 

support the state’s water reclamation program through 

rule for reclaimed water permits or for reviewing 

proposals. The draft rules are on hold due to 2011 

governor and legislative mandates to halt non-critical 

rule-making because of state budget constraints. 

Adoption of the draft regulation and the guidance 

manual is tentatively anticipated in 2013.

Current Guidelines

The 1997 standards drew heavily from California’s 

Title 22 recycled water program. The Washington 

State guidelines define four classes of reclaimed 

water, Class A, B, C and D, based on applied 

treatment processes and water quality (Table 1). 

Class A reclaimed water, the highest quality class, is 

oxidized, coagulated, filtered and disinfected. 

Reclamation plants must also meet reliability 

standards and have storage or alternate discharge 

locations for non-compliance. As the standards are 

based on 1997 common treatment technologies, other 

technologies are accepted if they can be demonstrated 

to provide the same level of treatment efficiency, 

reliability and public health protection.

Table 1

Requirements for reclaimed water in Washington State

Class

OXIDIZED COAGULATED FILTERED DISINFECTED

Secondary

Treatment

(mg/L)

Dissolved 

Oxygen Y/N Turbidity (NTU)

Total coliform 

(MPN/100 mL)

7-Day Median Single Sample

A 30 Must be 

present Yes 2 NTU avg. < 2.2 23 5 NTU max.

B 30 Must be 

present No No < 2.2 23

C 30 Must be 

present No No < 23 240

D 30 Must be 

present No No 240 N/A1

1 Not applicable

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The guidelines provide use area and water quality 

standards for the following beneficial uses of reclaimed 

water:

 Irrigation of food and non-food crops

 Landscape irrigation

 Landscape and recreational impoundments

 Commercial, municipal and industrial uses

 Groundwater recharge (by surface percolation 

or direct injection) 

 Streamflow augmentation

 Wetlands

Proposed Regulations 

In the 2006 draft regulation, the current four classes of 

reclaimed water would be streamlined to two: Class A 

and Class B. The regulation includes new provisions 

for production of Class A reclaimed water with 

membrane filtration and membrane bioreactor 

processes, for which stricter turbidity standards are 

provided. New virus removal standards for Class A 

reclaimed water are included: disinfection facilities 

must be designed to provide 5-log virus removal or 

inactivation (unless a 1-log filtration credit is 

applicable). Disinfection facilities must also be verified 

through a field-commissioning test prior to producing 

reclaimed water.

While Washington State law grants exclusive rights to 

distribute and use reclaimed water, the law also 

prohibits the facility from impairing existing 

downstream water rights without agreed compensation 

or mitigation. The draft regulation includes procedures 

for completing a satisfactory assessment of the 

potential to impair water rights that may be impacted 

by a water reclamation project. 

Rule-making Process

An advisory committee was created that included 

stakeholders representing affected regulatory 

agencies, public and private reclaimed water utilities, 

environmental organizations, water rights attorneys, 

Native American tribes, engineers, and potable water 

utility and local governmental organizations. Several 

subgroups studied specific areas and developed 

direction and language for the committee and 

agencies.

 Removing Barriers Subtask Force: Identified 

major road blocks to developing and 

implementing reclaimed water, such as 

restrictive regulations, funding limitations, and 

public perception of the product and where it 

could be used.

 Long Term Funding Subtask Force: Assessed 

the effect of financial limitations on development 

of water reclamation projects. 

 Water Rights Impairment Task Force: Defined 

the impacts and remedies for the effect on 

existing water rights when wastewater return

flows are reduced or removed. The group could 

not find consensus on solutions during their two 

year effort.

 Technical Advisory Panel: Provided technical 

expertise to address issues with applying and 

implementing new technologies, including how 

to assure public health protection through 

treatment. The final draft rule includes the 

panel’s recommendations.

 Trace Organics Committee: Considered 

concerns from the environmental community, 

such as potential public health and 

environmental impacts from trace organic 

chemicals in reclaimed water. The committee 

recommended no additional monitoring in the 

rule. They also requested that agencies remain 

cautious and be ready to respond as more 

information becomes available.

The advisory committee was still reviewing and

commenting on a well-developed draft rule when it 

was put on hold in 2011. Concerns included:

 Waters rights impairment: State law requires 

that a facility producing reclaimed water must 

not impair “existing downstream water rights” 

without agreed upon compensation or 

mitigation. The advisability of reducing or 

removing wastewater discharges to water 

bodies within watersheds closed to further water 

rights appropriations, and to streams with 

minimum in-stream flows set to protect aquatic 

habitats, is not yet resolved.

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 Rule implementation: What might happen during 

implementation of the rule as drafted? A 

guidance manual was initiated which would 

include details surrounding implementation. The 

manual was in its second draft when rule 

development was suspended.

Media Involvement 

The Washington rule-making process requires that all 

meetings be open to the public and public hearings be 

conducted. Meeting minutes and outcomes are 

available to the public electronically through the 

Department of Ecology website. Newspaper articles 

were written after the three public hearings. There was 

little public feedback (Washington State Department of 

Ecology, n.d). 

Details Particular to Washington 

The Washington State program is similar to, and builds 

on the California recycled water program for technical 

detail. The Washington State program has to refine 

certain administrative and policy details related to state 

organization and existing requirements.

 Lead agency: Responsibility is shared by two 

separate state agencies with similar but different 

requirements. To help avoid confusion, a “lead 

agency” and “non-lead agency” is designated 

for each project. Since Department of Health 

hasn’t developed a permit program for water 

reclamation yet, Department of Ecology will 

issue permits until then.

 Enforcement: The two state agencies have 

significantly different regulatory requirements 

and processes for enforcement. This has to be 

clearly addressed in the rule.

 Aquifer recharge responsibilities: RCW 90.46 

requires Department of Ecology to be 

responsible for land application projects. Aquifer 

recharge projects are, in concept, land 

application projects. Reclaimed water can 

recharge an aquifer and be recovered as a 

potable water supply, which is regulated by the 

Department of Health. Significant coordination is 

needed to assure public health and 

environmental protection without redundancy.

 Access to reclaimed water: RCW 90.46 grants 

the exclusive right to distribute and use 

reclaimed water to the owner of the facility 

producing the water. Current state laws are 

silent regarding control or access to “sewage” 

and “sewage effluent”. Areas served by regional 

collection and treatment entities and multiple 

public water systems have ownership and water 

rights disputes. This is a barrier to development

of satellite reclaimed water facilities.

 Fees: RCW 90.46 doesn’t give either agency 

authority to collect fees necessary to support 

the state’s water reclamation program through 

rule for reclaimed water permits or for reviewing 

proposals. Another legislative amendment will 

be needed to ensure the agencies receive fee 

support.

[Note that due to budget issues and staffing cuts the 

state's regulatory program will experience significant 

but as yet undefined changes after July 1, 2012.]

References

Washington State Department of Ecology, 2010. Chapter 

173-219 Washington Administrative Code - Draft Reclaimed 

Water. Washington State Department of Ecology, Olympia, 

Washington. 

Washington State Department of Ecology and Washington 

State Department of Health, 1997. Water Reclamation and 

Reuse Standards, Publication #97-23. Washington State 

Department of Ecology and Washington State Department of 

Health, Olympia, Washington.

Washington State Department of Ecology. n.d. Water Quality 

Website. Retrieved on Sept. 6, 2012 at 

<http://www.ecy.wa.gov/programs/wq/reclaim/index.html>. 

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2012 Guidelines for Water Reuse

Demonstrating the Safety of Reclaimed Water for Garden 

Vegetables

Author: Sally Brown, PhD (University of Washington)

US-WA-King County

Project Background or Rationale 

Currently, less than 1 percent of the 200 mgd (8760 

L/s) of wastewater that is treated in King County, 

Washington is treated to produce Class A reclaimed 

water, with the remainder discharged to Puget Sound. 

Concern over Puget Sound’s health and future nutrient 

discharge limitations prompted King County to explore 

reducing reliance on marine discharges. Increasing the 

use of reclaimed water could address this issue and 

assist with meeting existing and expected water 

demands. King County is constructing a new 

wastewater treatment facility designed to produce 

Class A reclaimed water using a membrane bioreactor 

(King County Reclaimed Water Division). In addition to 

this system, one of King County Reclaimed Water 

Division’s existing treatment plants produces small 

quantities of Class A water using sand filtration.

As part of the process to expand the reclaimed water 

program, a study was conducted to identify potential 

users for reclaimed water. End uses including industry, 

landscape irrigation, ecological enhancement, plant 

nursery, and truck farm irrigation were identified. Prior 

research and regulations in Washington State have 

established the safety and efficacy of reclaimed water 

for these end uses. In Washington, reclaimed water is 

regulated according to the Reclaimed Water Reuse 

Act of 1992, and is monitored by the Washington State 

Departments of Ecology and Health. Treatment 

requirements are dictated by the required effluent 

quality which is designated by the Class of reclaimed 

water, ranging from A–D, with A requiring the most 

stringent level of treatment and D requiring the least 

(Stensel, 2006). Class A reclaimed water is safe to use 

for watering food crops.

In King County, all reclaimed water meets Class A 

standards. However, to both gain customer confidence 

and illustrate that local soil and reclaimed water 

characteristics are suitable for the end uses identified, 

King County partnered with the University of 

Washington to conduct research on the safety and 

efficacy of Class A reclaimed water. One series of 

studies focused on the use of reclaimed water for truck 

farms—small-scale farms that grow fruits, vegetables, 

and flowers for local farmers markets and communitysupported agriculture (CSA) organizations. Here, the 

public concerns have bene centered on pathogens, 

potential for heavy metal accumulation, and changes 

in flavor as a result of using reclaimed water.

Reclaimed Water for Edible Crops 

The University of Washington conducted both a 

greenhouse study (Figure 1) and a field trial to 

demonstrate the low potential for pathogen transfer (as 

indicated by presence of bacteria indicator species) 

and metal uptake from reclaimed water to garden 

vegetables. Lettuce, carrots and strawberries were 

included in the study, as each of these are commonly 

grown by local farmers and each presents potential 

risk pathways to test the contaminants of concern.

Lettuce is known for high uptake of heavy metals and 

has been used as an indicator crop for metal 

availability (Brown et al., 1998). The edible portion of 

carrots is grown directly in soil and so may be more 

susceptible to pathogen contamination. Strawberries 

are often consumed without washing, also making 

them likely candidates for pathogen transfer. 

Figure 1

Greenhouse trial of Class A reclaimed water (Photo 

credit: Dana Devin Clarke)

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During the greenhouse and field studies, reclaimed 

water source samples were collected weekly; crop and 

soil samples were collected at the end of the study 

when plants were ready for harvest. Soils, water 

samples and washed and unwashed edible portions of 

plant tissue were analyzed for bacterial indicators 

(total coliforms, fecal coliforms, and E. coli) and metals 

(arsenic, cadmium, lead, and nickel). Metal 

concentrations in the reclaimed water were at least 2 

orders of magnitude below EPA regulations (Metcalf & 

Eddy, 2007). Bacteria tests were either negative or 

below the regulatory limit of 2 cfu/100 mL.

In general, metal uptake for plants grown using 

reclaimed water was similar to that for those grown 

with tap water. Results for lettuce from the field study 

are shown in Figure 2. 

In the greenhouse study, there were also no 

differences in bacterial indicators between the tap 

water irrigated crops or the reclaimed water irrigated 

crops for both washed and unwashed samples. Total 

coliforms were the only bacteria detected and they 

were only detected in the tap water control. In the field 

trial, total coliform counts were higher for all 

vegetables grown using reclaimed water in 

comparison to the tap water. This was likely due to 

increased contact with soil and coliform bacteria in the 

soil. Fecal coliform and E. coli were not detected in 

any of the vegetable samples grown in the field trial.

Public Outreach 

Results of both studies reflect the quality of the source 

water, with respect to bacterial indicators and metal 

concentrations. It could be argued that these studies 

were superfluous based on the analysis of the 

reclaimed water. However, public perception and 

understanding of reclaimed water is an essential 

component in the development of a beneficial use 

program. To that end, luncheons and tastings were 

held at the end of each year’s research. The first 

luncheon was limited to staff within the King County 

Wastewater Treatment division and featured 

presentations on the edible crops and ornamental 

plant research. Guests were served a main course and 

desert that included crops from the greenhouse study 

(Figure 3).

In the second year of the program, the luncheon was 

held at the wastewater treatment plant near the field 

site plots. Stakeholders, potential customers, and 

members of the community were invited. The menu 

was designed to feature crops grown in the garden 

and tables were decorated with flowers from the 

garden with bouquet giveaways at the end of the 

event. Presentations during the luncheon centered on 

results from these studies. Following the lunch, guests 

toured the gardens and were given bags to fill with 

potatoes (Figure 4). This type of outreach, in 

combination with research on locally produced 

reclaimed water has been an effective means for 

increasing acceptance and understanding of the safety 

and benefits of reclaimed water for irrigating food 

crops.

Figure 2

Metal concentrations in lettuce from field trial

Figure 3

Dr. Brown presenting study data at luncheon (Photo 

credit: Jo Sullivan)

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Lessons Learned

The research described here, demonstrates the 

absence of plant metal uptake and bacteria transfer, 

and largely confirmed what was anticipated based on 

characteristics of the Class A reclaimed water. The 

research was important however, as it provided local 

data to help the municipality build trust with potential 

customers for their product. The public outreach efforts 

were also a critical component for public acceptance. 

The King County Wastewater Treatment division now 

has a number of farmers interested in using the Class 

A reclaimed water. 

References

Brown, S.L., R.L. Chaney, J.S. Angle, and J. A. Ryan. 1998. 

“Organic carbon and the phytoavailability of cadmium to 

lettuce in long-term biosolids-amended soils”. J. Environ. 

Qual. 27:1071-1078.

King County Reclaimed Water Division website. 

n.d. Accessed September 5, 2012 at 

<www.kingcounty.gov/environment/wastewater/ResourceRecovery/

ReWater.aspx>.

Metcalf & Eddy. 2007. Water reuse. Issues, technologies, 

and applications McGraw-Hill Publisher, New York

Washington Department of Ecology website. 2011. 

Accessed September 5, 2012 at 

<http://www.ecy.wa.gov/programs/wq/reclaim/standards.html>. 

Figure 4

Harvesting potatoes after luncheon (Photo credit: Jo 

Sullivan)

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2012 Guidelines for Water Reuse

City of Yelm, Washington

Author: Shelly Badger (City of Yelm)

US-WA-Yelm

Project Background or Rationale 

The city of Yelm began its wastewater facility planning 

efforts to safeguard public health from septic system 

contamination of the area’s shallow drinking water 

wells. In 1990, the city chose an affordable option that 

included a centralized collection system and a 

secondary wastewater treatment lagoon discharging to 

the Nisqually River. This quickly became a short-term 

solution. The Nisqually River supports five species of 

Pacific salmon and sea-run cutthroat trout and ends in 

a national wildlife refuge. Yelm was under 

considerable legal pressure from a variety of parties to 

find a better environmental option. The community 

wanted to embrace reclaimed water as the best 

solution to safeguard public health, protect the 

Nisqually River, and to provide an alternate water 

supply for city use. However, Yelm faced a number of 

new challenges in implementing this strategy:

 Finding additional funding to upgrade the 

treatment plant – again.

 Building local support to make the project work.

 Locating customers who could use the water 

immediately.

Institutional and Cultural 

Considerations 

Yelm conducted intensive community outreach on 

these topics and as a result, in 1999 the city 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. 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. 

In 2002, the city received Ecology’s Environmental 

Excellence Award for successfully implementing Class

“A” reclaimed water into its community.

Capacity and Type of Reuse 

Application 

The Class A reclaimed water facility currently 

produces approximately 0.30 mgd (13 L/s) of 

reclaimed water and has capacity to produce up to 1.0 

mgd (44 L/s) to accommodate growth.

Water Quality Standards and 

Treatment Technology 

The Yelm reclamation plant had to modify the 

wastewater treatment plant significantly for reclaimed 

water production. The city chose to use sequencing 

batch reactor (SBR) technology for secondary 

treatment (biological oxidation) and nitrogen removal. 

Advanced treatment is followed by chemical 

coagulation, upflow sand filters, and chlorine 

disinfection. On-line monitoring of system and 

equipment performance provides that reclaimed water 

distributed to customers always meets the reclaimed 

water quality standards.

Project Funding and Management 

Practices 

The total project cost including engineering and 

construction was $9.6 million. Funding was provided 

from state and federal grants and loans, along with a 

local utility improvement district. Yelm’s annual 

operation and maintenance costs are approximately 

$1.4 million. This includes operator salaries and 

benefits, sewage collection, treatment and water 

reclamation, monitoring, solids removal, power, 

distribution, and public uses. The annual debt service 

for the project is $350,000.

Residential monthly sewer rates are $45.91 per month. 

The charge for a new residential connection is $6,219. 

Contractual agreements allow Yelm to recover some 

of the costs through charges for reclaimed water 

supplies. Yelm reclaimed water rates are 

approximately 80 percent of their drinking water rate.

D-172
Appendix D | U.S. Case Studies

2012 Guidelines for Water Reuse

References

Washington State Department of Ecology. 2005 Case 

Studies in Reclaimed Water Use – Creating New Water 

Supplies Across Washington State. Retrieved on Sept, 5, 

2012 from <http://www.ecy.wa.gov/pubs/0510013.pdf>.

D-173
Appendix C | U.S. Case Studies

2012 Guidelines for Water Reuse

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D-174
2012 Guidelines for Water Reuse E-1 

APPENDIX E 

International Case Studies and International Regulations

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

E-5 Argentina-Mendoza Special Restricted Crop Area in Mendoza, 

Argentina

Carl R. Bartone (Environmental 

Engineering Consultant)

E-8 Australia-Sydney Sewer Mining to Supplement Blackwater 

Flow in a Commercial High-rise Colin Fisher (Aquacell) 

E-11 Australia-Graywater Retirement Community Graywater Reuse Colin Fisher (Aquacell) 

E-13 Australia-Victoria End User Access to Recycled Water via 

Third Party-Owned Infrastructure Geoff Jones (Barwon Water)

E-15 AustraliaReplacement Flows

St Marys Advanced Water Recycling Plant, 

Sydney

Stuart Khan, PhD (University of South 

Wales) and Peter Chapman (Sydney 

Water)

E-18 Barbados-Economic 

Analysis

Economic Analysis of Water Reuse Options 

in Sustainable Water Resource Planning 

William Y. Davis and Jason Johnson, 

P.E. (CDM Smith)

E-21 Belgium-Recharge Water Reclamation for Aquifer Recharge in 

the Flemish Dunes 

Emmanuel Van Houtte, Intercommunale 

Waterleidingsmaatschapij van VeurneAmbacht (Intermunicipal Water 

Company of the Veurne Region, IWVA)

E-24 Brazil-Car Wash Car Wash Water Reuse – A Brazilian 

Experience

Rafael N. Zaneti, MSc; Ramiro G. 

Etchepare, MSc; and Jorge Rubio, PhD, 

DIC 

(Universidade Federal do Rio Grande 

do Sul)

E-27 Canada-Nutrient 

Transfer

Water Reuse Concept Analysis for the 

Diversion of Phosphorus from Lake Simcoe, 

Ontario, Canada

David C. Arseneau, P.Eng, MEPP 

(AECOM); David K. Ammerman, P.E. 

(AECOM); Michael Walters (Lake 

Simcoe Region Conservation Authority)

E-30 China-MBR Water Reuse in China

Allegra K. da Silva, PhD (CDM Smith) 

and Liping Lin (GE Water and Process 

Technologies)

E-33 Colombia-Bogotá The Reuse Scenario in Bogotá

Juan M. Gutierrez, MS (Javeriana 

University) and Lucas Botero, P.E., 

BCEE (CDM Smith)

E-36 Cyprus-Irrigation Water Reuse In Cyprus

Iacovos Papaiacovou and Constantia 

Achileos, MSc (Sewerage Board of 

Limassol Amathus); Ioanna Ioannidou, 

MSc, MBA (Larnaca Sewerage and 

Drainage Board); Alexia Panayi, MBA 

(Water Development Department); 

Christian Kazner, Dr.-Ing. (University of 

Technology Sydney); and Rita 

Hochstrat, MTechn. (University of 

Applied Sciences Northwestern 

Switzerland)

E-40 Ghana-Agriculture 

Implementing Non-conventional Options for 

Safe Water Reuse in Agriculture in 

Resource Poor Environments

Bernard Keraita, PhD and Pay 

Drechsel, PhD (International Water 

Management Institute)

1 To search for case studies by region or by category of reuse, please refer to Figure 9-1 
Appendix E | International Case Studies

E-2 2012 Guidelines for Water Reuse

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

E-43 India-Delhi

Reuse Applications for Treated Wastewater 

and Fecal Sludge in the Capital City of 

Delhi, India 

Priyanie Amerasinghe, PhD and Pay 

Drechsel, PhD (International Water 

Management Institute); Rajendra 

Bhardwaj (Central Pollution Control 

Board)

E-47 India-Bangalore

V Valley Integrated Water Resource 

Management: the Bangalore Experience of 

Indirect Potable Reuse

Uday G. Kelkar, PhD, P.E., BCEE and 

Milind Wable, PhD, P.E. (NJS 

Consultants Co. Ltd.); and Arun Shukla 

(NJS Engineers India Pvt. Ltd.)

E-51 India-Nagpur City of Nagpur and MSPGCL Reuse Project

Uday G. Kelkar, PhD, P.E., BCEE (NJS 

Consultants Co. Ltd) and 

Kalyanaraman Balakrishnan (United 

Tech Corporation)

E-54 Israel/JordanBrackish Irrigation

Managing Irrigation Water with High 

Concentrations of Salts in Arid Regions

Alon Ben-Gal, PhD and Uri Yermiyahu, 

PhD (Agricultural Research 

Organization, Gilat Research Center, 

Israel); Sirenn Naoum, PhD; 

Mohammad Jitan, PhD; Naeem 

Mazahreh, PhD; and Muien Qaryouti, 

PhD (National Center for Agricultural 

Research and Extension, Jordan)

E-58

Israel/Palestinian 

Territories/JordanOlive IrrigationIrrigation of Olives with Recycled Water

Arnon Dag, PhD; Uri Yermiyahu, PhD; 

Alon Ben-Gal, PhD; and Eran Segal, 

PhD (Agricultural Research 

Organization, Gilat Research Center, 

Israel) and Zohar Kerem, PhD (The 

Hebrew University of Jerusalem, Israel) 

along with colleagues from the 

Association for Integrated Rural 

Development, West Bank and the 

National Center for Agricultural 

Research and Extension, Jordan

E-60 Israel/Jordan-AWT 

Crop Irrigation

Advanced Wastewater Treatment 

Technology and Reuse for Crop Irrigation

Josef Hagin, PhD and Raphael Semiat, 

PhD (Grand Water Research Institute

Technion – Israel Institute of 

Technology, Haifa, Israel)

E-63 Israel/Peru-Vertical 

Wetlands

Treatment of Domestic Wastewater in a 

Compact Vertical Flow Constructed Wetland 

and its Reuse in Irrigation

Ines Soares, PhD; Amit Gross, PhD; 

Menachem Yair Sklarz, PhD; Alexander 

Yakirevich, PhD; and Meiyang Zou, 

MSc (Ben Gurion University of the 

Negev, Israel); and Ignacio Benavente, 

Eng, PhD; Ana Maria Chavez, Eng, 

MSc; Maribel Zapater, MSc; and Diana 

Lila Ferrando, Eng, MSc (Universidad 

de Piura, Peru)

E-66 Japan-Building MBR

A Membrane Bioreactor (MBR) Used for 

Onsite Wastewater Reclamation and Reuse 

in a Private Building in Japan

Katsuki Kimura, Dr.Eng. and Naoyuki 

Funamizu, Dr.Eng. (Hokkaido 

University, Sapporo, Japan)

E-69 Jordan-Irrigation Water Reuse and Wastewater Management 

in Jordan

Bader Kassab, MSc (USAID Jordan) 

and Ryujiro Tsuchihashi, PhD (AECOM)

E-71 Jordan-Cultural 

Factors

Cultural and Religious Factors Influence 

Water Reuse Tom A. Pedersen (CDM Smith)

E-74 Mexico-Tijuana Water, Wastewater, and Recycled Water 

Integrated Plan for Tijuana, Mexico Enrique López Calva (CDM Smith)
Appendix E | International Case Studies

2012 Guidelines for Water Reuse E-3 

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

E-76 Mexico-Mexico City The Planned and Unplanned Reuse of 

Mexico City’s Wastewater

Blanca Jiménez-Cisneros, PhD 

(Universidad Nacional Autónoma de 

México)

E-79 Mexico-Ensenada Maneadero Aquifer, Ensenada, Baja 

California, Mexico

Leopoldo Mendoza-Espinosa, PhD and 

Walter Daesslé-Heuser, PhD 

(Autonomous University of Baja 

California)

E-82 Mexico-San Luis 

Potosi

Tenorio Project: A Successful Story of 

Sustainable Development

Alberto Rojas (Comision Estatal del 

Agua), Lucina Equihua 

(Degremont S.A. de C.V.), Fernando 

Gonzalez (Degremont, S.A. de C.V.)

E-85 Pakistan-Faisalabad Faisalabad, Pakistan: Balancing Risks and 

Benefits

Jeroen H. J. Ensink, PhD (London 

School of Hygiene and Tropical 

Medicine)

E-88 Palestinian 

Territories-Auja

Friends of the Earth Middle East's 

Community-led Water Reuse Projects in 

Auja 

Elizabeth Ya'ari (Friends of the Earth 

Middle East)

E-90 Peru-Huasta Assessing Water Reuse for Irrigation in 

Huasta, Peru

Daphne Rajenthiram (CDM Smith); 

Elliott Gall and Fernando Salas 

(University of Texas) and Laura Read 

(Tufts University)

E-93 Philippines-Market

Wastewater Treatment and Reuse for Public 

Markets: A Case Study in Sustainable, 

Appropriate Technology in the Philippines

Mary Joy Jochico (USAID) and Ariel 

Lapus (USAID-PWRF Project)

E-96 Senegal-Dakar

Use of Wastewater in Urban Agriculture in 

Greater Dakar, Senegal: “Adapting the 2006 

WHO Guidelines”

Seydou Niang, PhD (Cheikh Anta Diop 

University of Dakar)

E-99 Singapore-NEWater

The Multi-barrier Safety Approach for 

Indirect Potable Use and Direct Nonpotable 

Use of NEWATER

Harry Seah, MSc and Chee Hoe Woo, 

MSc (PUB Singapore)

E-102 South AfricaeMalahleni Mine

Turning Acid Mine Drainage Water into 

Drinking Water: The eMalahleni Water 

Recycling Project

Jay Bhagwan (Water Research 

Commission)

E-104 South Africa-Durban Durban Water Recycling Project Jay Bhagwan (Water Research 

Commission)

E-107 Spain-Costa Brava

Risk Assessment for Legionella sp. in 

Reclaimed Water at Tossa de Mar, Costa 

Brava, Spain

Rafael Mujeriego, PhD (Universidad 

Politécnica de Cataluña) and

Lluis Sala, (Consorci Costa Brava) 

E-110 Thailand-Pig Farm

Sam Pran Pig Farm Company: Using 

Multiple Treatment Technologies to Treat 

Pig Waste in an Urban Setting

Pruk Aggarangsi, PhD (Energy 

Research and Development InstituteNakornping, Chiang Mai University, 

Thailand)

E-112 Trinidad and 

Tobago-Beetham

Evaluating Reuse Options for a Reclaimed 

Water Program in Trinidad, West Indies

Matt McTaggart, P.Eng, R.Eng; Jim 

Marx, MSc, P.E.; and Kathy 

Bahadoorsingh, PhD, R.Eng (AECOM)

E-114 United KingdomLangford Langford Recycling Scheme 

Afsaneh Janbakhsh, MSc, Cchem, 

MRSC, Csci (Northumbrian Water Ltd, 

UK)
Appendix E | International Case Studies

E-4 2012 Guidelines for Water Reuse

List of Case Studies by Title and Authors1

Page No. Text code Case Study Title Authors

E-116 United Arab 

Emirates-Abu Dhabi

Water Reuse as Part of Holistic Water 

Management in the United Arab Emirates

Rachael McDonnell, PhD (International 

Center for Biosaline Agriculture) and 

Allegra K. da Silva, PhD (CDM Smith)

E-120 Vietnam-Hanoi Wastewater Reuse in Thanh Tri District, 

Hanoi Suburb, Vietnam

Lan Huong Nguyen, MSc; Viet-Anh 

Nguyen, PhD ; and Eiji Yamaji, PhD; 

(Hanoi University of Civil Engineering, 

Vietnam)

Websites of International Regulations and Guidance on Water Reuse

Country Title of Regulations or Guidelines Link to Country Regulations or Guidance

Australia Guidelines for Environmental Management: 

Use of Reclaimed Water

http://epa.vic.gov.au/ourwork/publications/publication/2003/november/464-2

Australia Australian Guidelines for Water Recycling http://www.ephc.gov.au/taxonomy/term/39/

Brazil RESOLUÇÃO No 54, DE 28 DE 

NOVEMBRO DE 2005

http://www.aesa.pb.gov.br/legislacao/resolucoes/cnrh/54_2005

_criterios_gerais_uso_agua.pdf

Cyprus Τομέας Ελέγχου της Ρύπανσης http://www.moa.gov.cy/moa/environment/environment.nsf/All/2

6C40CAAAAEF746CC22578D1003B1FEA?OpenDocument

India General Standards for Discharge of 

Environmental Pollutants Part-A: Effluents http://cpcb.nic.in/GeneralStandards.pdf

Israel Uhttp://www.water.gov.il/Hebrew/ProfessionalInfoAndData/Wate

r-Quality/Pages/treated_waste_water.aspx?P=printU

Israel התקנות קובץ Uhttp://www.justice.gov.il/NR/rdonlyres/DF355FDA-0616-4D36-

B8D3-64F706C494C9/19866/6886.pdfU

Mexico Normas Oficiales Mexicanas ordenadas por 

Materia

Uhttp://www.semarnat.gob.mx/LEYESYNORMAS/Pages/nomsx

materia.aspxU

Mexico

Norma Oficial Mexicana Nom-001-Semarnat1996, Que Establece Los Límites Máximos 

Permisibles De Contaminates En Las 

Descargas De Aguas Residuales En Aguas Y 

Bienes Nacionales

Uhttp://www.bvsde.paho.org/bvsacd/cd38/Mexico/NOM001ECO

L.pdfU

Mexico Law: NOM-003-Semarnat-1997 Uwww.conagua.gob.mxU

Spain Spanish Regulations for Water Reuse Uhttp://www.asersagua.es/publicaciones/SpanishRegulationsfor

WaterReuseEN.pdfU

Thailand Pig Farm’s Standard Waste Water Level Uhttp://ptech.pcd.go.th/website/index.php?option=com_content

&view=article&id=22:wwstd&catid=8:envlaw&Itemid=31U

Vietnam National Technical Regulation on Water 

Quality for Irrigated Agriculture

Uhttp://www.epe.edu.vn/file/C__Documents%20and%20Setting

s_CQ%2040_Local%20Settings_Application%20Data_Mozilla

_Firefox_Profiles_6zquphxp.pdfU
2012 Guidelines for Water Reuse

Special Restricted Crop Area in Mendoza, Argentina

Author: Carl R. Bartone (Environmental Engineering Consultant)

Argentina-Mendoza

Project Background or Rationale 

Mendoza is located in an arid region in the foothills of 

the Andes in western Argentina. The city's wastewater 

has traditionally been used indirectly for irrigation. 

During the dry season, untreated wastewater 

represented 40 percent of resources available for 

irrigation in the Mendoza River Basin, raising serious 

health concerns (Zuleta, 2011).

At the time of this project, the greater Mendoza 

metropolitan area had 700,000 inhabitants, with 75

percent of the population connected to sewers. The 

projected population for 2010 was one million with a 

projected 95 percent sewer connection coverage 

(Idelovitch and Ringskog, 1997).

As part of the modernization of the water sector in the 

Province of Mendoza in the early 1990s, a number of 

reforms were put in place that helped introduce 

planned reuse of treated wastewater. One such case 

was the upgrading of the Campo Espejo waste 

stabilization ponds in 1993 and the introduction of 

microbiological standards for reuse.

Capacity and Type of Reuse 

Application 

The Campo Espejo waste stabilization ponds were 

built in 1976 and upgraded in 1996. The new plant 

consists of 12 modules of three waste stabilization 

ponds in series (facultative, aerobic, and polishing), 

occupying some 790.7 ac (320 ha) in total (Idelovitch 

and Ringskog, 1997). Today they provide 39 mgd 

(147,000 m3 /d) of effluent for direct irrigation (Zuleta, 

2011). 

The effluent from the Campo Espejo treatment plant is 

discharged to the Moyano Canal and conveyed to a 

special 6,672 ac (2,700 ha) restricted irrigation area, 

Area de Cultivos Restringidos Especiales (ACRE), for 

reuse (Zuleta, 2011). Farmers with properties within 

the special area receive treated effluent free of charge 

and are obliged to follow the irrigation regulations 

established for the ACRE. About one quarter of the 

irrigated area is devoted to the production of grapes, 

another quarter to the cultivation of tomatoes and 

squash, and the remaining area to the cultivation of 

alfalfa, artichokes, garlic, peaches, pears, and poplar 

biomass (Barbeito, 2001). The soil is slightly saline 

and therefore treated water is also used to wash salts 

from it (Jimenez, 2008).

Excess irrigation and drainage water from the Campo 

Espejo ACRE is discharged downstream into the 

Jocoli Canal, where it mixes with river water, and is 

used for the subsequent irrigation of an additional 

17,297 ac (7,000 ha) (Zuleta, 2011).

Water Quality Standards and 

Treatment Technology 

The provincial water and sanitation agency, Ente 

Provincial del Agua y Saneamiento (EPAS), was 

created in 1993 to regulate, control, and guarantee the 

provision of water and sewerage services in the 

Province of Mendoza. By means of EPAS’ Resolution 

35/96 (EPAS, 1996) standards were established for 

treated wastewater discharges and, in particular, for 

irrigation reuse in ACRE, including microbiological 

standards for fecal coliforms and nematodes. The 

latter standards were based on the World Health 

Organization Health Guidelines for the Use of 

Wastewater in Agriculture and Aquaculture. (WHO, 

1989). The upgrade of the Campo Espejo treatment 

plant in 1996 was in part to meet these new standards. 

Because of the generally low cost of land in Mendoza, 

waste stabilization ponds are a suitable treatment 

option for complying with the WHO guidelines.

Project Funding and Management 

Practices 

The upgrade was carried out under a 20-year buildown-operate-transfer (BOOT) concession from the 

metropolitan water and sewerage company, Obras 

Sanitarias de Mendoza (OSM), to the private operator 

Union Transitoria de Empresas (UTE). UTE operates 

and maintains the existing installations, as well as 

designs, constructs, andoperates the 12 new modules 

(Idelovitch and Ringskog, 1997). The bidding 

documents specified criteria for the quality of effluent, 

E-5
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

such as a maximum of 1,000 fecal coliforms per 100 

mL, a maximum of one helminth egg per liter, removal 

of at least 70 percent of biochemical oxygen demand, 

and removal of at least 30 percent of suspended 

solids.

Under the 1993 concession agreement, UTE 

committed to an initial investment of U.S. $15 million. 

The new plant was inaugurated in 1996. Under the 

BOOT agreement, UTE charges OSM U.S. $0.05 per 

m3 of wastewater treated. OSM guaranteed a 

minimum of 3 million m3 (793 million gallons) per 

month. Based on the average treated effluent flow, 

UTE’s initial investment had an expected payback 

period of 7 years.

Institutional/Cultural Considerations 

The chief provincial institutions responsible for 

wastewater treatment and use for irrigation in 

Mendoza are: OSM, which is responsible for water and 

sewerage services in Greater Mendoza; EPAS, which 

regulates and controls the provision of water and 

sewerage services; and the Departamento General de 

Irrigación (DGI), which is responsible for the 

management of water resources (Kotlis, 1998). 

A special Sanitation Planning process was developed 

for the Campo Espejo ACRE (Barbeito, 2001). 

Furthermore, regulations were promulgated governing 

the conformation and operation of the ACRE (DGI, 

2003). The DGI, OSM, and the ACRE Inspectorate 

were jointly responsible for developing and carrying 

out the Sanitation Plan and for supervising and 

controlling the direct use of treated wastewater in 

ACRE. The Inspectorate is comprised of members of 

the ACRE water users' association, and oversees the 

distribution of treated wastewater, control of authorized 

crops, irrigation methods allowed, and overall 

operational management within the ACRE.

The quality of the agricultural produce and the health 

of the agricultural workers are monitored by a special 

office of the DGI.

An agreement of cooperation was recently signed 

between OSM and ACRE farmers to study concerns of 

mutual interest, including the possibility of building 

effluent storage reservoirs that would optimize 

wastewater use during the dry season without 

requiring changes in the treatment plant operations, as 

well as the possibility of charging farmers part of the 

cost of treatment (Egocheaga and Moscoso, 2004).

Successes and Lessons Learned

The Mendoza ACRE model provides a practical and 

productive way of ensuring that there is sufficient land 

for the controlled use of available effluent from 

centralized treatment (Scheierling et al., 2010). 

Zuleta (2011) summarized the benefits of the ACRE 

model as providing for:

 Reliable and steady supply of water

 Reduced cost of treatment

 Management of microbial health risks

 Reduced soil and aquifer pollution

 Natural fertilization of soils

 Attenuated aquifer exploitation

Other ACREs have since been established in 

Mendoza, including for the Paramillos treatment plant 

and the Pescara Canal industrial zone.

References

Barbeito, E. 2001. Estudio general del caso: Campo Espejo 

del Aglomerado Gran Mendoza, República de Argentina. 

PAHO, Lima, Peru. 

DGI. 2003. Anexo I: Reglamento de Area de Cultivos 

Restringidos Especiales (ACRE). Resolución No. 400/03, 

Departamento General de Irrigación, Mendoza, Argentina.

Egocheaga, L. and J. Moscoso. 2004. Una estrategia para la 

gestión de las aguas residuals domésticas: haciendo más 

sostenible la protección de la salud en América Latina y 

otras regiones en desarrollo. PAHO, Lima, Peru. 

EPAS. 1996. Normas de calidad de agua y efluentes: Anexo 

II, Directrices sobre la calidad microbiologica de las aguas 

residuals empleadas en agricultura para riego restringido

(ACRE). Resolución No. 35/96, Ente Provincial del Agua y 

Saneamiento, Mendoza, Argentina.

Idelovitch, E. and K. Ringskog. 1997. Wastewater Treatment 

in Latin America: Old and New Options. New Directions in 

Development Series, The World Bank, Washington, D.C.

Jimenez, B. 2008. “Wastewater reuse in Latin America and 

the Caribbean.” In Water reuse: An international survey of 

current practice, issues and needs. Jimenez, B. and T. 

Asano (eds). Scientific and Technical Report No. 20, IWA 

Publishing, London.

Kotlis, L. 1998. “Water Reuse in Argentina.” Water Supply, 

16(1-2): 293-94.

E-6
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Scheierling, S.M., C.R. Bartone, D.D. Mara, D.D., and P. 

Drechsel. 2010. Improving wastewater use in agriculture: An 

emerging priority. Policy Research Working Paper 5412, The 

World Bank, Washington, D.C.

WHO. 1989. Health Guidelines for the Use of Wastewater in 

Agriculture and Aquaculture. Technical Report Series No. 

778, World Health Organization, Geneva.

Zuleta, J. 2011. Integrated planning for direct wastewater 

irrigation in Mendoza, Argentina. Seminar Presentation, The 

World Bank, Washington, D.C. Retrieved on Sept. 5, 2012

<http://water.worldbank.org/sites/water.worldbank.org/files/5.

%20Zuleta%20Mendoza.pdf>. 

E-7
2012 Guidelines for Water Reuse

Sewer Mining to Supplement Blackwater Flow in a 

Commercial High-rise

Author: Colin Fisher (Aquacell) 

Australia-Sydney

Project Background or Rationale 

Australia’s warm climate and habitual droughts have 

resulted in innovative water conservation practices in 

commercial developments, such as 1 Bligh Street in 

Sydney. Commissioned in May 2011, the highly 

acclaimed 29 story office tower overlooking the 

Sydney Harbor captures nearly 100 percent of its 

wastewater and reuses it in the building. By recycling 

the vast majority of the waste stream, the developers 

have avoided sewer capacity issues and reduced the 

building’s freshwater demand by approximately 90

percent. Not all of the wastewater reused at Bligh 

Street comes from the building itself. 

Calculations revealed the building’s total waste stream 

would not meet the non-potable demand for cooling 

tower makeup and toilet flushing (the desired reuse 

applications). Rather than supplementing non-potable 

demand with city water, the development has engaged 

in ‘sewer mining’, which involves tapping into the city’s 

sewer main as a source of water (see Figure 1). 

Capacity and Type of Reuse 

Application 

The blackwater plant, located just off the parking 

garage in a maintenance room, treats approximately 

26,000 gallons (100 m3

) of blackwater onsite daily. 

A modular membrane bioreactor (MBR) was chosen, 

which would meet Water Industry Competition Act 

(WICA) and project objectives. Advances in modular 

mechanical design, membrane and instrument 

development, and remote monitoring via the Internet 

have helped improve the cost and reliability of MBR 

systems significantly in recent years. The MBR 

treatment consists of mechanical screening, biological 

treatment, and ultrafiltration (UV) (0.04 micron 

membranes). This approach provides the building a 

small footprint system with high yields (more than 99

percent) and high quality effluent. Disinfection via UV 

and a chlorine residual follows the MBR to provide 

multiple barriers of treatment. The recycled water 

reused for cooling tower makeup is also treated with 

reverse osmosis to remove salts.

Water Quality Standards and 

Treatment Technology 

The reuse scheme required a New South Wales 

(NSW) WICA operator’s and retail license. The NSW 

government introduced WICA in 2006 as part of its 

strategy for a sustainable water future. WICA is 

intended to harness the innovation and investment 

potential of the private sector in the water and 

wastewater industries. At the same time, the Act 

establishes a licensing regime for private sector 

entrants to ensure the continued protection of public 

Figure 1

Bligh St Sewer mining and reuse schematic

E-8
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

health, consumers, and the environment (Independent 

Pricing and Regulatory Tribunal, 2011). 

A corporation (other than a public utility) must obtain a 

license under the Act to construct, maintain or operate 

any water industry infrastructure, supply water (potable 

or non-potable), or provide sewerage services by 

means of any water infrastructure.

The approach in the WICA legislation is based on the 

Australian Guidelines for Water Recycling (AGWR); a

risk based methodology that provides a framework for 

assessing the risks associated with reuse projects 

(Natural Resource Management Ministerial Council, 

Environment Protection and Heritage Council and 

Australian Health Ministers’ Conference, 2006). The 

Bligh Street treatment program was deemed 

appropriate for the particular reuse scheme and 

adequate to manage the associated risks.

The application process for Bligh Street was done at 

the state level, submitted to the Independent Pricing 

and Regulatory Tribunal (IPART), which is responsible 

for ensuring a level playing field for private and public 

suppliers. IPART then sent the application to Public 

Health Offices for their input and it was also posted on 

IPART’s website for public comment. Environmental 

concerns, plumbing and drainage codes, sewer 

access, waste disposal licenses, and potable water 

backup were all taken into consideration at this time. 

Successfully passing an independent audit of the 

treatment plant infrastructure and associated system 

management plans is additionally required for the plant 

to begin treating wastewater. Next, a verification 

period was initiated, where the treated water is 

sampled and tested according to a sampling protocol 

from the management plan. The plant must 

demonstrate the water is “fit for purpose” before 

treated water can be distributed throughout the 

building.

Institutional/Cultural Considerations 

The Australian Guidelines for Water Recycling

employs a “fit for purpose water” methodology (Natural 

Resource Management Ministerial Council, 

Environment Protection and Heritage Council and 

Australian Health Ministers’ Conference, 2006). This 

approach involves an exposure risk calculation 

adopted from the World Health Organization’s (WHO) 

Guidelines for Drinking-water Quality (WHO, 2004). 

The methodology designates tolerable risk to be 10-6

Disability Adjusted Life Years (DALYs), or 1 infection 

per 1,000,000 people per year. DALYs have been 

used extensively to account for illness severity by 

organizations such as WHO. For this particular site, in 

order to reach 10-6 DALYs for Protozoa, Viruses, and 

Camplyobacter, calculations determined Log 

Reduction Values (LRVs) needed to be 4.6, 6.0, and 

4.8, respectively. Information on how these 

calculations are performed can be found in tables, 3.3, 

3.7, and A2.1 of the AGWR (2006). Once LRVs have 

been established, plant performance objectives and 

components can be determined. In this case, a UV unit 

provides 1 LRV for Viruses and 4 LRV for Protozoa. A 

reverse osmosis (RO) unit provides >1 for each and 

chlorine disinfection provides 4 LRV for viruses. Thus, 

the performance requirements for the system are met. 

Note that in the LRV calculations there are no LRV 

credits sought for the submerged membranes. This 

may change in the future as California Title 22 gains 

wider acceptance.

Project Funding and Management 

Practices 

The Bligh Street scheme was funded entirely by the 

building’s developer thus it was critical the blackwater 

scheme be commercially viable from the outset. An 

innovative risk management methodology was 

adopted at first principles to properly address the 

economic challenges small schemes face with ongoing 

operations. 

For many years the food industry has used Hazard 

Analysis and Critical Control Points (HACCP) risk 

management methodology. More recently HACCP has 

been adopted in the water industry. In a HACCP 

assessment the process is broken down into steps and 

at each step the question “what might happen and how 

might it occur” is asked. At Bligh Street, 6 CCPs were 

identified. These are influent pH, Turbidity, Electrical 

Conductivity across the RO, UV dosing, Chlorine 

residual and effluent pH. For each CCP, upper and 

lower limits were identified. If, during the course of 

production any one of the six CCPs is outside the 

limits, production is halted and an alarm is sent via 

SMS to a technician. Thus, HACCP ensures water 

quality fit for purpose will be delivered. As a result, end 

of pipe monitoring frequency can be reduced 

accordingly which reduces lab costs and directly 

effects the viability of the treatment plant without 

sacrificing public safety. Whereas E. coli sampling 

might have typically been required daily on a project 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

like Bligh Street, with HACCP real-time verification 

monitoring in place, regulators agreed to monthly 

sampling of E. coli. The monthly sampling for E. coli

simply serves as confirmation that the HACCP 

methodology is functioning properly. 

Lessons Learned

The Bligh Street project was one of the first NSW 

WICA licensing schemes in Sydney Central Business 

District to include sewer mining for cooling tower 

reuse. Working in an uncharted regulatory 

environment is always challenging and requires a 

vendor that fully understands risk assessment, and 

treatment technology, and has operational experience. 

Permitting is one of the more significant hurdles often 

overlooked by private scheme proponents. The 

permitting process can be time consuming. As new 

regulations are phased in, there is a period of overlap 

where the existing and new regulations both apply. 

The potential for miscommunication and confusion 

between regulatory bodies and the applicants is real. 

In order to meet all requirements, applications under 

the existing and the new regulations have been filed in 

parallel, which doubles the effort involved. Officials are 

extremely cautious at every step of the process and 

this has the effect of slowing down the process to a 

point where a 12-month lead time for approvals is 

normal. Accordingly, customers who would like to 

engage water recycling should be aware that the 

approval process adds a dimension of complexity and 

cost to the project. This will change as officials 

become more familiar with the practice and regulations 

and requirements for small systems become more 

transparent. 

References

Independent Pricing and Regulatory Tribunal. 2011. 

Licensing: Private Water Utilities. [Cited 15 December 2011]. 

Retrieved on Sept. 5, 2012 from

<http://www.ipart.nsw.gov.au/Home/Industries/Water/Private

_Sector_Licensing_WICA>. 

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. Natural Resource Management Ministerial Council, 

Environment Protection and Heritage Council and Australian 

Health Ministers’ Conference, Canberra, Australia. [Cited 15 

December 2011]. Retrieved on Sept. 5, 2012 from 

<http://www.ephc.gov.au/sites/default/files/WQ_AGWR_GL_

_Managing_Health_Environmental_Risks_Phase1_Final_20

0611.pdf>. 

World Health Organization. 2004. Guidelines for Drinkingwater Quality. World Health Organization, Geneva, 

Switzerland. Retrieved on Sept. 5, 2012 from 

<http://www.who.int/water_sanitation_health/dwq/GDWQ200

4web.pdf>.

E-10
2012 Guidelines for Water Reuse

Retirement Community Graywater Reuse

Author: Colin Fisher (Aquacell) 

Australia-Graywater

Project Background or Rationale 

RSL Care’s Sunset Ridge Retirement Community 

resides near the Pacific coast in Zilzie, Queensland, 

Australia. The retirement community includes 100 

independent living villas, a 120-bed aged care 

residential complex, and resort style facilities. Although 

Zilzie averages 31 in (79 cm) of annual rainfall, RSL 

Care sought to install a graywater recycling system 

because of the environmental benefits and to secure 

and maintain an adequate water supply for the 

community’s residents. 

Capacity and Type of Reuse 

Application 

The graywater treatment plant installed at the Sunset 

Ridge Retirement Community treats approximately 

6,600 gallons (25 m3

) of graywater per day. The plant 

captures graywater discharged from the community’s 

showers, bathtubs, and hand basins. The treated 

water is then reused in all of the toilets on site and for 

landscape irrigation. 

Water Quality Standards and 

Treatment Technology 

In Queensland, all graywater treatment plants must be 

granted Chief Executive Approval by the Queensland 

Department of Infrastructure and Planning before they 

are allowed to operate (Queensland Australia 

Government, 2011). Formal approval is based on 26 

weeks of independent monitoring to demonstrate that 

the plant is able to treat graywater to the regulated 

quality standards. Once a system has been approved, 

it can be employed in other projects of similar nature.

Where treated graywater is used in high level reuse 

applications (e.g. toilets, urinals, laundry reuse, vehicle 

washdown) the Queensland regulations require the 

treated effluent to achieve the following minimum 

quality: 

 BOD5 <10 mg/L

 TSS <10 mg/L

 E. coli (max) <10 cfu/100 mL 

 E. coli (95th percentile) <1 cfu/100 mL 

 turbidity (max) <5 NTU 

 turbidity (95th percentile) <2 NTU 

The challenge of meeting these effluent standards in 

decentralized scenarios is that wastewater quality and 

flows are often highly variable. As such, the design of 

the treatment plant needs to be robust enough to 

manage a range of situations. 

The core technology at Sunset Ridge is a modular 

membrane bioreactor (MBR), which encompasses a 

bioreactor with ultrafiltration membranes of 0.04

micron. MBRs are an advanced low footprint treatment 

technology typically used for blackwater treatment. 

However, this technology has been adopted to treat 

graywater primarily because of the soluble and 

insoluble organics that are commonly seen in 

commercial graywater influents. Graywater is by no 

means clean water with a few dirt particulates. 

Filtration based processes are sometimes used to 

treat graywater, but they do not provide the resilience 

needed for commercial systems, which MBRs afford. 

Once the effluent has been through the ultrafiltration 

membrane in the MBR, it is disinfected with ultraviolet 

(UV) and chlorine to achieve a chlorine residual. This 

multi-barrier treatment approach is what ensures the 

treatment plant is able to confidently handle variable 

wastewater qualities that are typical of decentralized

graywater schemes. 

Project Funding and Management 

Practices 

One of the key considerations that clients and 

regulators want addressed when establishing reuse 

treatment plants of any size is who will operate the 

plant in the long-term This is especially important if the 

scheme is to be implemented by the private sector for 

a specific private project. In this case, RSL Care 

privately funded the graywater scheme at Sunset 

Ridge. 

Reuse schemes require a long-term strategy and 

cannot be treated as a fixed piece of plumbing 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

equipment. The challenge for many private sector 

decentralized reuse schemes is that they typically do 

not have wastewater specialists located on site. 

Therefore, longer-term arrangements need to be 

considered early on and should inform decision 

making throughout the project. For example, a cheap 

solution with poor equipment may win on capital price, 

but may also lead to the highest overall life cycle costs 

because of poor performance and operational 

difficulties. Life cycle analysis (LCA) must be 

considered.

The Sunset Ridge graywater plant operation is 

managed as a shared responsibility between the 

onsite maintenance staff at Sunset Ridge and the 

graywater system contractor. Day to day servicing and 

management is provided by Sunset Ridge locally, with 

twice yearly full technical servicing, remote monitoring, 

and regulatory reporting being provided by the 

contractor. Different projects will have different 

maintenance arrangement outcomes.

Institutional/Cultural Considerations 

The graywater contractor is able to provide local staff 

with a high level of support particularly due to the 

capabilities of its risk management methodology in 

combination with the system’s built-in remote 

monitoring system. Utilizing Hazard Analysis and 

Critical Control Points (HACCP), a risk management 

methodology most commonly used in the food and 

beverage industry, the graywater contractor can 

ensure the delivery of high quality treated water. 

Different Critical Control Points (CCPs) of the 

treatment process are monitored in real-time providing 

data to the contractor. Corrective actions are 

programmed into the system if any of the CCPs are 

out of range, thus providing Sunset Ridge an 

additional layer of confidence with the quality of the 

treated graywater. In addition to the safety provided by 

the HACCP risk management approach, remote 

monitoring and controls allow technical staff to take the 

reins of the graywater plant if necessary. Operational 

data from the CCPs is continuously relayed back to 

the contractor’s headquarters where technical staff can 

increase/decrease aeration levels, change chlorination 

dosing, turn pumps on/off and so on. Remote 

monitoring and controls means the client has the 

security of knowing operational experts always have 

an eye on the plants operation. 

Results and Lessons Learned

The Sunset Ridge graywater plant has consistently 

met effluent quality expectations since commissioning 

in early 2010 and the success of the scheme can be 

summarized down to contractor experience. It is 

important that managing regulatory approvals, 

delivering a robust technology suitable for commercial 

applications (commercial and domestic approaches 

are very different), and ensuring the appropriate 

operational partnerships are established and 

considered at the onset of the project.

References

Queensland Australia Government. 2011. Queensland 

Development Code Part MP 4.3. Retrieved on Sept. 5, 2012 

from 

<http://www.hpw.qld.gov.au/construction/BuildingPlumbing/P

ages/default.aspx>.

E-12
2012 Guidelines for Water Reuse

End User Access to Recycled Water via Third PartyOwned Infrastructure

Author: Geoff Jones (Barwon Water)

Australia-Victoria

Background 

Barwon Water supplies recycled water from five of its 

nine water reclamation plants (WRP). During times 

where there is no customer demand, the recycled 

water is discharged to the ocean, lakes or onsite tree 

lots. The water is used for a number of commercial 

and municipal uses, including:

 Irrigating golf courses, sporting grounds, and 

public open spaces

 Irrigating vineyards, hydroponic tomatoes, 

potatoes, and other crops 

 Irrigating turf and flower farms 

 Dust suppression for road works and major 

construction works

Barwon Water is a government owned water authority 

operating in Victoria, Australia. In Victoria recycled 

water schemes must be approved by the Environment 

Protection Authority (EPA Victoria) and recycled water 

pricing must be approved by the Victorian Essential 

Services Commission (ESC).

Recycled Water Schemes

Barwon Water does not construct the recycled water 

distribution infrastructure. Transport of recycled water 

from the WRP to a customer’s reuse site is the 

responsibility of the recycled water customer. 

Generally a single large customer within a distribution 

network funds construction, operation and 

maintenance of the distribution pipelines. These 

infrastructure owners transport the recycled water from 

Barwon Water WRPs to other customers. 

Infrastructure owners are able to recover their capital 

and operational costs by charging an infrastructure 

service fee in addition to the cost of the water from 

Barwon Water. In this arrangement, even though 

Barwon Water does not own the distribution assets, 

Barwon Water has been able to supply additional 

customers via the privately owned infrastructure.

All private scheme owners pay Barwon Water to 

maintain and service their network.

Three main recycled water networks (schemes) have 

been constructed in the region:

 Torquay Scheme (Black Rock WRP) - 1997

 Portarlington Scheme - 1999

 Barwon Heads Scheme (Black Rock) - 2000

In all three of these schemes, the majority of the 

distribution infrastructure is owned by one of the 

recycled water customers.

This arrangement is uncommon in Australia as most 

recycled water schemes are usually wholly owned and 

operated either by the water authority or a private 

owner.

Recycled Water Quality

The recycled water supplied is guaranteed as Class C 

quality as defined by EPA Victoria (Table 1) which 

implies suitability for a range of agricultural and 

horticultural purposes.

Table 1 EPA Victoria Class C recycled water license

limits (EPA, 2003)

Parameter Range

E. coli < 1000 org/100 mL

pH 6 to 9

BOD < 20 mg/L 

SS < 30 mg/L 

These are the only guaranteed parameters—other 

parameters are monitored but not guaranteed. 

Legal Agreements

Barwon Water uses two legal agreements for 

supplying recycled water. EPA Victoria provides 

guidance on the content of legal supply agreements; 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

however this advice is brief and limited to suggested 

contents.

Recycled Water Supply Agreement: This agreement 

is between Barwon Water and the recycled water 

customer. Barwon Water treats all customers the 

same, the approach does not alter if they receive their 

water directly or via a privately-owned pipeline. The 

Supply Agreement states that the customer must 

negotiate directly with the infrastructure owner for 

access to their pipeline. An Infrastructure Access 

Agreement is negotiated between these parties.

Other conditions of the Supply Agreement include:

 An annual allocation (maximum volume) is 

defined, however this is not guaranteed due to 

unforseen events.

 The quality is only guaranteed to a specific 

class, not individual parameters. The end user 

accepts responsibility for suitability of the 

recycled water to their purpose.

 The pressure is not guaranteed, nor is the 

recycled water supplied at a pressure suitable to 

power irrigation equipment. All end users must 

store the water and apply it at their own cost. 

 A “take-or-pay” clause ensures that an 

allocation is not “locked up” unused. This clause 

is only enforced when other customers are able 

to use the water not currently being used.

Infrastructure Access Agreement: This agreement 

is between the infrastructure owner and the recycled 

water customer. 

Infrastructure Access Agreements have been written 

to various levels of detail, from a one page letter to a 

several page legal agreement. Barwon Water has 

developed a pro-forma agreement to assist new 

customers reach agreement with the infrastructure 

owners. The pro-forma agreement is provided to 

customers to use or modify as they see fit.

Fees and Tariffs 

In accordance with ESC pricing principles, Barwon 

Water's recycled water tariff is calculated to only 

recover the cost of production. No additional profit 

margin is included. 

In addition to Barwon Water's recycled water tariff, 

customers are also charged for transfer of the recycled 

water by the private scheme owners. These owners 

may seek one or more of the following fees from the 

customer:

 Once-off connection fee

 Annual fee (based on either the end user annual 

volume (allocation) or a portion of the overall 

scheme capital)

 Volumetric (transfer) fee

While not a party to the negotiation, Barwon Water 

must be satisfied the agreement is fair and 

reasonable. Despite no legal regulation for this 

requirement, Barwon Water has been able to facilitate 

these negotiations. In newer agreements, a clause is 

specifically included to ensure that private scheme 

owners are obliged to accept reasonable requests by 

new customers to access their infrastructure.

Successes and Lessons Learned

Barwon Water has intervened twice to mediate better 

terms (i.e., cheaper price) for new customers. Both 

times the scheme owners were intending to charge 

customer an exorbitant volumetric transfer fee.

Over time the various agreements have been 

improved by way of new and revised clauses. The 

current arrangements include a more robust arbitration 

process. 

To date, this form of supply arrangement has worked 

well and in the last 14 years facilitated the reuse of 

more than 12,200 acre-feet or 4,000 billion gallons 

(15,000 mL) of water.

References

EPA. 2003. Guidelines for Environmental 

Management: Use of Reclaimed Water [publication 

464.2]. EPA Victoria, Southbank, Victoria.

E-14
2012 Guidelines for Water Reuse

St Mary’s Advanced 

Water Recycling Plant, Sydney

Authors: Stuart Khan, PhD (University of South Wales) and 

Peter Chapman (Sydney Water)

Australia-Replacement Flows

Project Background or Rationale 

Drinking water supplies in the main storage reservoir 

for Sydney (Warragamba Dam) were rapidly 

diminishing between 2000 and 2006. The declining 

storage volume was primarily due to severe drought in 

the greater Sydney region. During this time, 

Warragamba Dam was also required to continue to 

provide satisfactory environmental flows in the 

downstream Hawkesbury Nepean River system.

The St Marys Advanced Water Recycling Plant is 

based in western Sydney and was developed by 

Sydney Water as a component of the New South 

Wales (NSW) State Government’s Metropolitan Water 

Plan. The objective of the project was to produce an 

alternative high quality water source to replace more 

than 4.8 billion gallons (18 billion liters) of drinking 

water annually released from Warragamba Dam for 

the environmental flows of the downstream river, and 

improve river health through reducing the nutrient load.

Three existing wastewater treatment plants (St Marys, 

Penrith, and Quakers Hill) were identified, that could 

together supply the required volumes of source water 

to a new water recycling plant at St Marys. Advanced 

water treatment processes were required to ensure 

that the recycled water would be of a water quality 

standard suitable for environmental release into the 

Hawkesbury Nepean River system. 

Capacity and Type of Reuse 

Application 

A new advanced water recycling plant was designed to 

produce up to 4.8 billion gallons (18 billion liters) of 

highly treated recycled water annually. 

The water recycling plant receives tertiary treated 

wastewater from the three wastewater treatment 

plants in variable ratios, depending on demand. 

Advanced treatment is then applied by ultrafiltration 

(UF) and reverse osmosis (RO), followed by 

decarbonation and chlorine disinfection.

Water Quality Standards and 

Treatment Technology 

Water quality and treatment performance were subject 

to rigorous scrutiny by the relevant public health 

regulator, the NSW Department of Health (NSW 

Health). The Australian Guidelines for Water Recycling 

(AGWR) require the adoption of a risk management 

framework for managing water quality (NRMMC, 

EPHC, and NHMRC, 2006). An important aspect of 

the framework is a risk assessment to identify key 

potential hazards and hazardous events that may lead 

to elevated risks to the community. Although these 

guidelines were in draft form at the time, NSW Health 

imposed general compliance with the guidelines and 

the presentation of a satisfactory risk assessment as 

key criteria to be met in order for the project to receive 

the necessary endorsement for planning approval.

Risk Assessment and Performance 

Validation 

A screening level human health risk assessment was 

undertaken at the concept stage for the St Marys 

project by the University of New South Wales (UNSW) 

(Khan et al., 2007). Partially on the basis of that 

assessment, the NSW Government (including NSW 

Health) approved construction of the advanced water 

recycling plant with a number of conditions. One of 

those conditions was the construction and 

performance assessment of a pilot-scale plant. The 

pilot was constructed and a comprehensive chemical 

risk assessment and treatment performance 

assessment was then undertaken by UNSW (Khan et 

al., 2009). 

As an essential component of the chemical risk 

assessment, a chemical monitoring program was 

developed with the primary aim of validating many of 

the assumptions made in the screening-level risk 

assessment (Drewes et al., 2010). This chemical 

monitoring program demonstrated that key prioritized 

chemicals of potential toxicological concern (including 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

pharmaceuticals, endocrine disrupting chemicals, and 

emerging disinfection by-products) in the product 

water were either absent or present at trace 

concentrations that were not a risk to human health for 

downstream users of the river.

Lognormal probability plots were prepared for 

statistical analysis of the variability in concentrations of 

chemical contaminants in UF influents and filtrates; 

and RO influents permeates and three-stage 

concentrates (“conc 1”, “conc 2” and “conc 3”). An 

example is provided for the chemical 

dibromochloromethane in Figure 1. 

The full-scale water recycling plant was then 

constructed adjacent to the site of the existing St 

Marys wastewater treatment plant and commissioned 

in June 2010. This was immediately followed by a 42-

day process proving period, which included validation 

monitoring. 

An objective of the chemical validation monitoring was 

to confirm that the performance of the new full-scale 

plant was comparable to the pilot-scale plant, which 

had been subject to a more intensive performance 

assessment. The focus of the validation was on the 

reverse osmosis process since the pilot-scale 

assessment confirmed that this was the most 

important and effective barrier to trace chemical 

contaminants present in feed water. The validation 

testing successfully confirmed that the full-scale water 

recycling plant was operating with equivalent 

performance to the pilot plant (Khan and McDonald, 

2010). Monitoring of chemical indicators in the 

recycled water provided evidence of high level of 

treatment performance and ultimately led to the final 

approval by NSW Health.

Project Funding and Management 

Practices 

The project was funded through Sydney Water’s 

customer charges as approved by Sydney Water’s 

economic regulator, the NSW Independent Pricing and 

Regulatory Tribunal (IPART). Following a competitive 

tender process, Deerubbin Water Futures was 

engaged to design and construct the scheme, and 

operate and maintain the new advanced water 

recycling plant for a 10 year period.

Operations of the new advanced plant and transfer 

system have been completely integrated with the 

existing three wastewater plants, which are still 

required to meet pre-existing recycled water supply 

requirements for municipal 

irrigation and downstream 

irrigators.

Institutional/Cultural 

Considerations 

Planning approval for the 

overall project included conditions of public consultation, 

and the proposed project was 

reviewed at public forums as 

part of the Metropolitan Water 

Plan. The project team also 

worked closely with the community while 32 miles (52 

kilometers) of pipelines were 

laid through residential 

suburbs of western Sydney. 

Several heritage areas were 

identified and protected by 

boring the necessary pipework 

beneath them. The team consulted indigenous Aboriginal 

groups on managing 

Figure 1

Example of comprehensive monitoring of chemical contaminants in the St Marys 

Water Recycling Plant

LOR = limit of reporting

E-16
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

significant artifacts, and monitored and recorded 

artifacts during the excavation works.

Successes and Lessons Learned

The project was completed on time, below budget, and 

met all objectives. The plant was officially launched in 

October 2010.

Water quality from the new plant has exceeded 

expectations on all quality parameters. To date, actual 

concentrations of nutrients are about half the predicted 

amounts, further reducing the nutrient load in the 

Hawkesbury-Nepean River. A Recycled Water 

Education Centre has also been included in the plant.

A key lesson learned from a project delivery and 

operations perspective, was that integration was 

critical. Successful operation of the plant relies on the 

ongoing contribution of approximately 20 different 

teams within Sydney Water, with one manager 

providing leadership and strategy. The approach taken 

through design and construction and into the 

operations and maintenance phase was to engage 

stakeholders early, and integrate the project into 

standard systems, processes, procedures and 

responsibilities, in order to realize the benefits of the 

project and achieve performance targets.

The initial construction of an in situ pilot plant for the 

risk assessment phase was also shown to be a highly 

worthwhile investment. With scalable technologies 

such as membranes, the pilot plant enabled realistic 

testing of the plant performance using water obtained 

from the actual catchment and this provided a high 

level of confidence to inform the design and 

construction of the full-scale plant.

References

Drewes, J.E., J.A. McDonald, T. Trinh, M.V. Storey, and S.J. 

Khan. 2010. “Chemical monitoring strategy for the 

assessment of advanced water treatment plant 

performance.” Water Science & Technology: Water Supply, 

10(6): 961-968.

Khan, S.J. and J.A. McDonald. 2010. Replacement Flows: 

Chemical Validation Monitoring. Report for Sydney Water 

Corporation. UNSW Water Research Centre, University of 

New South Wales.

Khan, S.J., D.J. Roser, N.J. Ashbolt, A. Lovell, and M. 

Angles. 2007. “Health risk assessment for recycling for 

replacement river flows.” In Water Reuse & Recycling. 

Khan, S.J., R.M. Stuetz, and J.M. Anderson (Eds). UNSW 

Publishing, Sydney, 263-272. ISBN: 978 0 7334 2517 2.

Khan, S. J., McDonald, J. A., Trinh, T., and Drewes, J. E. 

2009. Sydney Water Replacement Flows Project: Chemical 

Risk Assessment. UNSW Water Research Centre, Sydney.

National Resource Management Ministerial Council 

(NRMMC), Environment Protection and Heritage Council 

(EPHC), and National Health and Medical Research Council 

(NHMRC). 2006. National Guidelines for Water Recycling: 

Managing Health and Environmental Risks (Phase 1).

E-17
2012 Guidelines for Water Reuse

Economic Analysis of Water Reuse Options in Sustainable 

Water Resource Planning

Authors: William Y. Davis and Jason Johnson, P.E. (CDM Smith)

Barbados-Economic Analysis

Project Background or Rationale 

The West Coast Sewerage Project is a plan by the 

Barbados Water Authority to provide sewer service to 

residents and businesses on the west coast of the 

island nation of Barbados. The designated “West 

Coast” area is a strip of land between the Caribbean 

coast and the base of the lower terrace. The area is 

approximately one-half mile wide from east to west 

and about 12 miles (20 km) from north to south. The 

white sand beaches and accessible coral reefs draw 

tourists from around the world. The West Coast is 

densely developed and accounts for about 80 percent 

of Barbados’ billion dollar (U.S.) annual tourism 

industry.

The Government of Barbados signed onto 

international agreements related to the discharge of 

water through ocean outfalls to marine environments. 

In addition, the Government of Barbados mandated 

the appropriate implementation of water reuse into the 

water management strategy for the country.

The proposed West Coast Sewerage project has 

multiple components that address collection, 

treatment, and disposal. Option A called for a 

collection system with a secondary treatment facility at 

the south end of the region where an ocean outfall 

could be constructed without impacting coral reefs. In 

addition, five alternative discharge/disposal options 

(Options B, C, D, E and F) were considered with 

different configurations of reuse distribution systems 

and aquifer recharge. 

The level of treatment is consistent for each option 

since the international agreements mandate advanced 

treatment requirements similar to those required for 

water reuse and recharge to potable aquifers. 

A prior study determined the reuse potential of golf 

courses and other industries in proximity to the West 

Coast. Most of the potential for golf course irrigation 

with reclaimed water is midway up the West Coast and 

would occur only during the dry season. Aquifer 

recharge areas in proximity to the West Coast are in 

potable aquifer zones while non-potable aquifer zones 

are further distances from the planned treatment 

facilities.

Economic Analysis

The quantifiable present worth costs and benefits were 

estimated for each option. The economic benefits 

included residents’ willingness to pay for sewage 

service, reduction of sanitation costs at commercial 

establishments, tourists’ willingness to pay for sewage 

service, value of water reuse, reduced beach erosion, 

avoidance of beach closures, enhanced tourism 

activities, and public health. The value of water reuse 

was determined as the cost of the water to be used if 

reclaimed water were not available. Thus, costs were 

determined for potable water, desalinated water for 

irrigation, groundwater for irrigation, and brackish 

water for cooling.

The costs and benefits of each option were discounted 

from their future values to an equivalent present value 

for comparison. A range of discount rates was used to 

test the sensitivity of the results to changes in the 

discount rate. The different discount rates affected the 

net project costs but did not change the ranking of the 

options in the quantifiable economic analysis. Results 

using a discount rate of 6 percent are show in Table 1. 

Table 1 Economic indicators

Options A B C D E F 

Costs $270 $371 $398 $322 $350 $381

Benefits $427 $500 $500 $490 $490 $500 

NPV $156 $129 $102 $168 $141 $119

BC Ratio 1.58 1.35 1.26 1.52 1.40 1.31 

ERR 11.8% 9.7% 8.8% 11.6% 10.5% 9.6% 

Dollars are U.S. million

Discount rate is 6%

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Based solely on the quantitative criteria, Option A was 

the most cost-effective option as it had the lowest 

costs, the highest ratio of benefits to costs (BC Ratio) 

(1.58) and the highest economic internal rate of return 

(EIRR) (11.8 percent). Option C, on the other hand, 

had the highest costs, the lowest benefit to cost ratio 

(1.26) and the lowest economic internal rate of return 

(8.8 percent) of the six options. Even though Option C 

ranked lowest among the options, it is still 

economically viable in that the benefits exceed the 

costs and the rate of return is acceptable.

Triple Bottom Line 

The multi-criteria analysis evaluated the options based 

on environmental, social, and operational factors. The 

environmental factors included marine impacts, 

groundwater impacts, provision of a saltwater barrier 

for aquifers, overall sustainability, and odor control. 

Social factors included disruption during construction, 

overall public acceptance, meeting the government’s 

objectives of compliance with marine discharges and 

reuse, land use conflicts, and promoting public 

education and awareness of stewardship of water 

resources. The operational factors included system 

reliability, flexibility complexity and emergency 

responsiveness, with a preference for less complexity 

and more reliability, flexibility and responsiveness in 

operations. 

Weights ranging from 1 (low importance) to 5 (high 

importance) were assigned to each of these factors. 

Ratings on a scale of 0 (not applicable) to 10 (highest) 

were assigned to each option for each of these factors. 

These weightings and ratings were assigned, reviewed 

and refined in a stakeholder workshop. 

Option C had the best (highest) score followed by 

Option A. On the environmental criteria, Option B had 

the highest score and Option A the lowest. On the 

social criteria, Option A is the least disruptive and thus 

scored best socially. Operationally, Option A is the 

most reliable and the least complex. However, Option 

C has the highest overall score.

Rankings of the options based upon results of the 

cost-benefit analysis and the multi-criteria analysis are 

shown in Table 2. Table 2 shows the rankings for both 

weighted and unweighted scores. The unweighted 

score gives equal weight to the five indicators (multicriteria score and four economic indicators). In the 

unweighted score, the environmental and social 

impacts represent only 20 percent of the overall score. 

Alternatively, weights were assigned to the five 

indicators to provide a weighted score of indicators. A 

variety of weighting scenarios was used to test the 

sensitivity of the rankings to changes in the weighting 

of indicators. For example, the weighted score shown 

in Table 2 is based upon a weight of 70 percent for the 

multi-criteria score with the remaining 30 percent 

divided equally among the four economic indicators. 

Table 2 Overall rankings

Options A B C D E F 

Life-cycle Costs (US$ million) $270 $371 $398 $322 $350 $381

Rank (1=lowest) 1 4 6 2 3 5 

NPV* (US$ million) $156 $129 $102 $168 $141 $119

Rank (1=lowest) 2 4 6 1 3 5 

BC Ratio* 1.58 1.35 1.26 1.52 1.40 1.31

Rank (1=lowest) 1 4 6 2 3 5 

EIRR* 11.8% 9.7% 8.8% 11.6% 10.5% 9.6%

Rank (1=lowest) 1 4 6 2 3 5 

Total MCA Score 700 653 723 605 679 676

Rank (1=lowest) 2 5 1 6 3 4 

Unweighted Score 7 21 25 13 15 24

Unweighted Rank 1 4 6 2 3 5 

Weighted Score 1.78 4.70 2.50 4.73 3.00 4.30

Weighted Rank 1 5 2 6 3 4 

* At 6% discount rate

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

In the weighted analysis, Option A received the best 

ranking regardless of the weighting of indicators. 

However, Option A does not meet the government 

mandate to develop a water management strategy that 

includes the reuse of valuable wastewater effluent. 

The analysis illustrates that meeting this reuse 

mandate imposes the acceptance of certain economic, 

environmental and social costs.

Summary 

The importance of operational criteria became evident 

through the stakeholder workshop process. Barbados 

Water Authority staff determined that management of 

“worst-case” conditions of a highly complex 

wastewater and reclaimed water system was a critical 

factor. Thus, options were limited to those that 

included the ocean outfall infrastructure for emergency 

backup disposal in the rare instance of a plant failure. 

Again, the analysis illustrated the additional economic, 

environmental and social costs, or trade-offs, imposed 

operational preferences and the reuse mandate.

References

CDM, Benefit-cost Analysis for the West Coast Sewerage 

Project Master Plan (WCSMP), completed for the Barbados 

Water Authority, 2009.

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2012 Guidelines for Water Reuse

Water Reclamation for Aquifer Recharge

in the Flemish Dunes

Author: Emmanuel Van Houtte, Intercommunale Waterleidingsmaatschapij van VeurneAmbacht (Intermunicipal Water Company of the Veurne Region, IWVA)

Belgium-Recharge

Project Background or Rationale 

In the western part of Belgium’s Flemish coast, water 

demand increased from 426 ac-ft (526,000 m3) in 1950 

to 4,500 ac-ft (5,500,000 m3) in 1990. The dune water 

catchments, where fresh groundwater is pumped from 

the unconfined aquifer by the Intermunicipal Water 

Company of the Furnes Region (IWVA), could no 

longer produce more water as continued pumping

could cause saline intrusion. Ecological interest in the 

dunes was also growing (Van Houtte and 

Vanlerberghe, 1998), so alternative exploitation

methods were studied to remediate decreasing water 

levels and to guarantee current and future water 

extraction possibilities. This resulted in the 

development of a project for artificial recharge of the 

unconfined dune aquifer of St-André. Because no 

other water sources were available for year-round

aquifer recharge, the IWVA decided to use reclaimed 

water from the Torreele facility for the production of 

infiltration water (Van Houtte and Vanlerberghe, 2001).

Capacity and Type of Reuse 

Application 

The Torreele facility in Wulpen indirectly reuses 

reclaimed water to augment the potable water supply. 

The largest portion of the reclaimed wastewater is 

from households. The treatment process consists of 

primary sedimentation, predenitrification, and aerobic 

treatment, followed by secondary clarification and RO. 

Because the rainwater is collected in the same sewer 

system, the effluent water quality can vary greatly. In 

the first 9 years of operation, 4.6 billion gallons (17.5 

million cubic meters) of infiltration water was produced 

at Torreele. Before being recharged in a 196,000 ft2 

pond (18,200 m2) in the dunes of St-André, the water 

undergoes a small pH correction dosing with NaOH. 

The extraction rate was 6.2 billion gallons (23.6 million 

m3) during that period, and the average residence time 

in the dunes was 55 days (Vandenbohede et al., 

2009).

The recovered water is conveyed to the potable water 

production facility at St-André which consists of 

aeration, rapid sand filtration, storage, and ultraviolet 

(UV) disinfection prior to distribution. Dosing of 

chlorine is possible as a preventive action to prevent 

regrowth and recontamination in the distribution 

network.

Since the project started, 35 to 40 percent of IWVA’s 

annual drinking water demand is fulfilled by the 

combination of reuse/recharge.

Water Quality Standards and 

Treatment Technology 

The recharge water is subject to stringent water quality 

standards due to the sensitive environmental nature of 

the dune area to be recharged (Table 1). Because

reclaimed water is high in both salt and nutrient 

content, RO was chosen as the final treatment step at 

the Torreele facility. RO requires a high-quality 

influent, so UF membranes precede the RO process

(Figure 1).

Table 1 Quality standards set for the infiltration water

Parameter Infiltration water

Conductivity (μS/cm)

Chloride (mg Cl/l)

Sulphate (mg SO4/l)

Total hardness (°F)

Nitrate (mg NO3/l)

Nitrite (mg NO2/l)

Ammonia (mg NH4/l)

Total phosphorous (mg P/l)

1,000

250

250

40

15

0.1

1.5

0.4

The RO system is a two-stage configuration with 21:6 

pressure vessels in the first pass and 10:6 pressure 

vessels in the second pass. Scaling is prevented by 

pH adjustment and antiscalant dosing. Biofouling is 

prevented by dosing monochloramines. The average 

annual recovery is 77 percent. 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Water reuse intended for drinking water production, 

both direct and indirect, is not possible without 

intensive water quality monitoring. Both UF and RO

processes performed as expected – UF produced

water free of bacteria and suspended solids. UF

proved to be a good pretreatment for RO, and the 

infiltration water meets the quality standards that were 

set for the infiltration water (Table 2).

Table 2 Overview of quality in 2010

Parameter Infiltration Water

Conductivity (μS/cm) 45 (<10 – 89)

pH 6.29 (5.28 – 6.86)

Total Organic Carbon (mg/l) 0.4 (0.1 – 1.1)

Total hardness (mg/l as CaCO3) <0.5

Chlorides (mg /l) 3.2 (1.0 – 4.7)

Fluorides (mg/l) <0.2

Sulfates (mg/l) <1

Nitrate (mg NO3/l) 2.5 (<1 – 6.3)

Ammonia (mg NH4/l) 0.13 (0.03 – 0.38)

Phosphate (mg PO4/l) <0.1

Silicium (mg SiO2/l) 0.3 (0.1 – 0.4)

Total trihalomethanes (μg/l) 3.8 (1.2 – 6.7)

Aluminum (μg/l) 12 (2 – 59)

Chromium (μg/l) <2.5

Copper (μg/l) <5

Lead (μg/l) <5

Mercury (μg/l) <0.2

Nickel (μg/l) <3

Sodium (mg/l) 10.5 (4.5 – 17.7)

Zinc (μg/l) <20

Totale Coliform bacteria 

(counts/100 ml) 0 

E. coli (counts/100 ml) 0 

HPC 22°C (counts/ml) <1 (0 – 10)

Project Funding and Management 

Practices 

The project was funded with IWVAs resources; no 

external funding was used. The total investment was 7 

million Euros ($9 million) and the contractors remained 

responsible during a 10-year period. The daily 

operation is conducted by IWVA.

All membranes have been replaced only once since 

startup: the RO membranes in 2009, and the UF 

membranes between 2009 and 2011.

Successes and Lessons Learned

Meteorological and seasonal variations are a big 

challenge at the Torreele facility and influence

operating conditions. Ongoing monitoring at the plant 

includes online and daily measurements taken by the 

operator.

Submerged UF (ZeeWeed), using outside-in filtration 

and air not only proved to be a good pretreatment prior 

to RO, but was also capable of handling the expected 

variations in influent water quality. Suspended solids 

and bacteria were removed from the water and 

turbidity is monitored as the first quality control step. 

Biofouling and scaling prevention is a constant 

concern with water reuse when using membranes. 

Reduction in consumption of chemicals and energy 

has been achieved since start-up by reducing aeration 

in the UF system, optimizing RO recovery rates to 

minimize scaling, and intermittent chloramination for 

control of biofouling (Van Houtte and Verbauwhede, 

2008).

The membrane waste concentrate streams are now 

combined with the portion of the treated wastewater 

that is not reclaimed and discharged in the nearby 

brackish canal. However, IWVA investigated natural 

systems for concentrate treatment (Van Houtte and 

Verbauwhede, 2011).

Temperature influences the volume of infiltration; more 

water is infiltrated in summer when temperatures are 

higher, which matches IWVA’s demand for drinking

water in a tourist area. The project was developed for 

an extraction rate of 1.4 times the infiltration rate. 

During the first years of operation, there was a surplus 

of recharged water. Since the beginning of 2009, 

however, the accumulated surplus appears to be

corrected and currently averages 264 million gallons (1 

million m3). In winter the surplus decreases as colder 

temperatures have a negative impact on the infiltration 

rate. Though Vandenbohede et al. (2008) predicted a 

dynamic equilibrium would not occur, even after 10 

years of recharge, it appears that equilibrium may 

have already occurred. The latest ratio over the last 12 

months for recharge/infiltration rate was 1:39, 

indicating that the dynamic equilibrium has been

reached.

In recent years the drinking water demand in the area 

decreased from 1.5 billion gallons (5.5 million m3) in 

2002 to just below 1.3 billion gallons (4.9 million m3) in 

E-22
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

2010. Public education on the proper use of drinking

water, increased prices due to higher taxes for 

discharge of the used water, and decreased leakage 

of the distribution network all contributed to this

decrease. It is difficult to make a prognosis on how the 

evolution will be in the next years but the decreased 

use of drinking water meant that less infiltration has 

been required in recent years. 

References

Vandenbohede, A., Van Houtte, E. and Lebbe, L. 2009.

Water quality changes in the dunes of the western Belgian 

coastal plain due to artificial recharge of tertiary treated 

wastewater. Applied Geochemistry 24 (2009) 370–382. 

Van Houtte, E and F. Vanlerberghe, 1998. Sustainable 

groundwater management by the integration of effluent and 

surface water to artificially recharge the phreatic aquifer in 

the dune belt of the western Flemish coastal plain. IAH

International Groundwater Conference, Groundwater: 

Sustainable Solutions, Melbourne, Australia, p 93-99.

Van Houtte, E. and F. Vanlerberghe, 2001. Preventing 

biofouling on RO membranes for water reuse - Results of 

different tests. AWWA Membrane Technology Conference, 

San Antonio, 2001.

Van Houtte, E. and J. Verbauwhede, 2008. Operational 

experience with indirect potable reuse at the Flemish coast, 

Desalination 218 (2008), p 198-207.

Van Houtte, E., Berquin, S., Pinoy, L. and J. Verbauwhede, 

2012. Experiment with willows to treat RO concentrate. 

Presentation in preparation for AMTA Membrane 

Conference in Glendale, AZ, 2012.

Figure 1 Process scheme of Torreele

E-23
2012 Guidelines for Water Reuse

Car Wash Water Reuse – A Brazilian Experience

Authors: Rafael N. Zaneti, MSc; Ramiro G. Etchepare, MSc; and Jorge Rubio, PhD, DIC 

(Universidade Federal do Rio Grande do Sul)

Brazil-Car Wash

Project Background or Rationale 

A full-scale car wash (hand washing) facility in Porto 

Alegre, South Brazil demonstrates the ability to utilize 

wastewater reuse (reclamation) for commercial car 

washing. This project validates an innovative 

process—Flocculation-Column Flotation (FCF), 

filtration, and chlorination—proposed by Rubio and 

Zaneti (2009), and Zaneti et al. (2011). Full evaluation 

was performed over a period of 20 weeks. The main 

parameters monitored were water consumption, 

quality of the reclaimed treated wastewater, water 

risks to health (customers and operators), vehicles, 

and washing machine damages.

Capacity and Type of Reuse 

Application 

The installed car wash wastewater reclamation system 

(Figure 1) had capacity for reclaiming 264 gallons/hr 

(1 m3

/hr) to meet the requirements for a demand of 

around 60 car washes per day. 

Neutral and alkali detergents, as well as waxes are 

employed in the wash procedure. Reclaimed water 

was utilized in the pre-soak, wash and first rinse (wash 

process). Makeup (fresh) water was used in the final 

rinse before the cars were dried. Water usage was 

monitored daily by single-jet water meters. A single 

three stage oil/water separator was employed after the 

wash rack to remove excess oil content (free oil) and 

grit particles.

Water Quality Standards and 

Treatment Technology 

The water quality for vehicle washing has to be 

sufficiently high to avoid damage to vehicles and 

washing equipment (Brown, 2002). In addition, the 

water quality must minimize risk to operators and 

users and be aesthetically acceptable, lacking odor 

and having a turbidity of less than 15 NTU (Jefferson 

et al., 2004). 

The FCF principle is to encourage rapid formation of 

flocs, followed by flotation using fine (micro) bubbles to 

remove particles. Chlorine is then used to disinfect the 

FCF treated wastewater. The floc generator reactor 

(FGR) (Carissimi et al., 2007) and the flotation column 

(Zaneti et al., 2011) are patented processes and are 

low energy, easy to control, and compact. The FCF 

system was run semi-automatically. The water level in 

the reclaimed water tank was monitored with an 

electric level sensor, triggering the treatment process 

to turn on automatically when sufficient volume was 

reached in the tank. A tannin-based polymer 

(concentration of 80–350 mg L-1) was used in the 

coagulation-flocculation step and sodium hypochlorite 

(0.5 mg Cl2 L-1) to disinfect the effluent. 

Study Methods and Results 

To ensure acceptable human health risk, risk analysis 

was performed employing dose-response models 

(Haas et al., 1999) using E. coli as an indicator of 

microbiological quality. Aerosol and ingestion 

exposure routes were considered for car wash 

Figure 1 

Car wash water reclamation system - Total storage 

capacity: 2,640 gallons (10 m3). Stages include: 1.) Handoperated car wash; 2.) Oil/water separator; 3.) Wastewater 

reservoir (sample point 1); 4.) FCF equipment; 5.) 

Reclaimed water reservoir (sample point 2); 6.) Fresh water 

supply; 7.) Sludge dewatering.

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

customers (1 exposure per week) and operators (15 

exposures per day). 

Corrosion and/or scaling are the main concerns in 

wastewater reclamation systems for vehicle washing 

(Metcalf & Eddy, 2006). Total dissolved solids (TDS) 

and chloride were monitored and predicted using a 

mass balance model, assuming constant inputs of 

contaminants per wash cycle and no water loss. 

The chemical, physicochemical and micro-biological 

water analysis results are shown in Table 1. Samples 

were collected at points 1 and 2 (Figure 1) and 

analyzed using standard methods (APHA 2005).

Table 1

FCF-SC process: Characteristics of wastewater and 

reclaimed water (20 samplings; mean values ±

1/2 standard deviation)

Parameters Wastewater

Reclaimed 

Water

Examination 

Methods*

pH 7.4 ± 0.8 7.3 ± 0.5 -

TSS, mgL-1 89 ± 54 8 ± 6 2540 D 

TDS, mgL-1 344 ± 25.5 388 ± 42 - 

Turbidity, NTU 103 ± 57 9 ± 4 2130 B

Total coliforms, 

CFU/10

3.1E ± 5 3.3E ± 4 9223 B

E. coli, CFU/ 

100 mL-1 

2.1E ± 4 7.4E ± 2 9221 E

* APHA, 2005.

Results showed that reclamation of 70 percent of the 

feed water was possible [only 11 gallons (42 L) of 

fresh water per car] in order to maintain odorless and 

clear water over 27 water cycles. A risk analysis 

indicated that car wash users were not at risk, and that 

a limit of 200 CFU 100mL-1 of E. coli would be 

recommended for an acceptable risk for car wash 

operators (risk analysis data not shown). This would 

be achieved, by increasing the chlorine concentration 

to 15 mg CL2 L-1 (data not shown). Moreover, the 

mass balance analysis indicated that the reclaimed 

water will have dissolved inorganic constituents below 

guideline parameters (TDS < 1000 mgL-1 and chloride 

< 400 mg.L-1) (Nace 1975). 

Project Funding and Management 

Practices 

The work was supported by several research and 

educational institutions in Brazil, mainly the Ministry of 

Science and Technology and the Ministry of 

Education. 

Successes and Lessons Learned

Based on comparison to other studies, reducing fresh 

water consumption in car washes is more effective 

through wastewater reclamation rather than rainwater 

harvesting systems (Zaneti et al., 2011). Rainwater 

harvesting for water savings in petrol stations with car 

washes in Brasilia, Brazil was studied by Ghisi et al. 

(2009). The author reported that large roof areas 

(550 m2) and a large tank (100 m2) are required to 

capture intermittent rainfall to reach the same 70

percent of water savings attained in the present study 

(at a demand of 15 car washes per day). Furthermore, 

according to the results of these authors, rainwater 

harvesting systems require longer pay-back periods 

for installed equipment. 

In this study, more than 2000 cars were washed (16 

daily washes) during the study period (20 weeks), with 

no reported problems regarding the wash service 

quality. The results have encouraged the application of 

FCF-SC process in many Brazilian bus companies and 

in more environmentally friendly car washes. However, 

public policies need to be developed that help to 

encourage effective implementation of water reuse, 

including by addressing water pricing.

References

APHA - Standard Methods for the Examination of Water and 

Wastewater, 2005. 21st, American Public Health 

Association/American Water Works Association/Water 

Environment Federation, Washington, D.C., USA.

Brown C., 2002. Water use in the Professional Car Wash 

Industry. Report for International Car Wash Association, 

Washington D.C., USA.

Carissimi E, Miller JD, Rubio J. 2007. Characterization of the 

high kinetic energy dissipation of the flocs generator reactor 

(FGR). International Journal Mineral Processing, 85(1–

3):41–9.

Ghisi E, Tavares D F, Rocha V L. Rainwater harvesting in 

petrol stations in Brasília: Potential for potable water savings 

and investment feasibility analysis. Resources, Conservation 

and Recycling 2009;54:79–85.

Haas C, Rose J, Gerba C. Quantitative microbial risk 

assessment. New York: John Wiley & Sons; 1999.

Jefferson B., Palmer A., Jeffrey P., Stuetz R. and Judd S., 

2004. Grey water characterization and its impact on the 

selection and operation of technologies for urban reuse. 

Water Science and Technology, 50(2), 157-164.

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Metcalf and Eddy, 2006. Water Reuse: Issues Technologies, 

and Applications. New York, USA.

National Association of Corrosion Engineers (NACE). The 

corrosivity of recirculation car wash water. NACE 1975; 

3N275:9-10.

Rubio J. and Zaneti R.N., 2009. Treatment of washrack 

wastewater with water recycling by advanced flocculation–

column flotation. Desalination, 8, 146-153.

Zaneti R, Etchepare R, Rubio J., 2011. Car wash 

wastewater reclamation: Full-scale application and upcoming 

features. Resources, Conservation and Recycling, 55, 953-

959.

E-26
2012 Guidelines for Water Reuse

Water Reuse Concept Analysis for the Diversion of 

Phosphorus from Lake Simcoe, Ontario, Canada

Author: David C. Arseneau, P.Eng, MEPP (AECOM); David K. Ammerman, P.E. 

(AECOM); Michael Walters (Lake Simcoe Region Conservation Authority) 

Canada-Nutrient Transfer

Project Background or Rationale 

Lake Simcoe is one of the largest inland lakes in 

Ontario, Canada and supports a cold-water 

recreational fishing community that is vital to the local 

tourism economy. Human activity over the last two 

centuries has degraded water quality in the Lake, 

creating significant eutrophication from excessive 

phosphorus loading. The Lake Simcoe area is 

serviced by 14 water pollution control plants (WPCP), 

which discharge 5.3 tonnes of phosphorus per year 

(MOE, 2010). Such impacts are anticipated to increase 

due to the rapidly growing population. The Lake 

Simcoe Protection Act mandates the reduction of 

phosphorus discharges into the Lake, including 

effluent from all WPCPs servicing the urban areas of 

the watershed. 

Costly upgrades to WPCP treatment technologies 

have been proposed to meet these reductions. In the 

interest of pursuing alternative means of reducing 

phosphorus loadings, this study was commissioned by 

the Lake Simcoe Region Conservation Authority 

(LSRCA) and Ministry of 

Environment (MOE) to 

evaluate the feasibility of 

implementing water reuse 

applications to divert 

effluent from the Lake. 

Implementing reclaimed 

water programs can divert 

wastewater effluent, and 

the associated nutrients, 

away from receiving 

watercourses while 

providing non-potable 

water for uses such as 

irrigation of farms and golf 

courses. Water reuse is an 

emerging practice in 

Ontario, with few 

implemented projects and 

an absence of dedicated 

legislation or policies to 

establish acceptable end 

uses or water quality 

requirements.

Figure 1

Illustration of the demand screening analysis for the Keswick Water Pollution 

Control Plant

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Methodology 

The water reuse conceptual analysis consisted of four 

stages. This approach was designed to address key 

questions to establish the feasibility of 

water reuse to contribute to the reduction 

of phosphorus loadings to Lake Simcoe:

1. Characterization of potential water 

reuse applications: what types of 

reuse applications are available in the 

watershed, how much water do they 

need, and how much phosphorus is 

diverted or reduced?

2. Characterization of reclaimed water 

supplies: where are the treatment 

plants located, how much reclaimed 

water is potentially available, what is 

the quality of the reclaimed water 

(i.e., which reuse application is the 

water suitable for), and what is the 

current phosphorus load from each 

plant?

3. Reclaimed water demand screening 

analysis: which water reuse 

applications are available in proximity 

to each of the treatment plants 

(Figure 1), what are the annual reclaimed water 

demands, and what is the potential annual 

phosphorus reduction?

4. Conceptual water reuse scenarios: what are the 

costs and benefits associated with the water reuse 

applications, as established through three 

conceptual scenarios?

The water reuse scenarios evaluated in this study 

included:

 Keswick WPCP: irrigation of sod farms

 City of Barrie: satellite reuse facility for reuse in 

new growth urban areas

 Uxbridge Brook WPCP: municipal effluent

disposal via land application

Findings 

The results of the cost assessment are shown in 

Table 1. The costs are reported on a dollars per 

kilogram of phosphorus removed ($/kg P) to facilitate 

comparison with other phosphorus reduction methods 

in the watershed, such as treatment plant upgrades, 

stormwater management and agricultural controls, as 

part of a potential credit trading program. Figure 2

provides a comparison of water reuse scenario 

Irrigation of agricultural areas can be a cost-effective 

alternative to installation of tertiary filtration at existing 

secondary treatment facilities. These costs do not 

consider the potential benefits to farmers with respect 

to water security, reduced pumping costs and reduced 

need for added fertilizer. The land application (i.e., 

disposal) scenario becomes relatively cost-effective 

when considering installation of tertiary filtration at 

small treatment plants, as well as when upgrading 

existing sewage lagoons into secondary treatment 

plants. Urban reuse applications were not found to be 

cost-effective when solely considering phosphorus 

removal; however there are many other benefits to 

urban reuse, including reduction of potable water 

demands, alleviation of municipal servicing and 

water/wastewater plant capacity restrictions, 

conservation of natural water resources and potential 

improvements to potable water quality in distribution 

pipes due to smaller pipe sizes. Recognition of these 

additional benefits for both irrigation and urban reuse 

should be developed to further characterize the 

potential for reuse as a viable means of reducing 

phosphorus loadings. 

Figure 2

Comparison of water reuse cost-effectiveness (Magenta, AECOM) 

with treatment plant upgrade cost-effectiveness (Blue, XCG, 2010) in 

reducing phosphorus loadings

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Conclusions 

This study demonstrates the evaluation of the potential 

cost-effectiveness of water reuse for a variety of 

applications. The methodology used is scalable to 

large or small areas, and the parameters of the 

analysis can be readily modified to suit the 

management objectives of the operating authority, 

agency or municipality. 

References

Ministry of Environment of Ontario. Lake Simcoe 

Phosphorus Reduction Strategy. PIBS 7633e. Queen’s 

Printer for Ontario, 2010. 

XCG, Keiser Associates. Water Quality Trading in the Lake 

Simcoe Watershed, Feasibility Study. Feb. 2010.

Table 1 Summary of reuse scenario costs and phosphorus removal rates

Reuse Scenario

25-year Life 

Cycle Cost 

($CAD 2010)

Annual 

Phosphorus 

Removed 

(kg/yr)

Percent 

Phosphorus 

Reduction 

(%/year)1

25-year 

Phosphorus 

Removal (kg)

Phosphorus 

Removal Cost 

Effectiveness 

($/kg P)

Keswick WPCP Sod Farm 

Irrigation $5.4-$10.4MM 116-184 22%-35% 2,900-4,600 $1,850-$2,250

Barrie Reuse for New Urban 

Development $4.7-$9.5MM 12.6 0.50% 315 $14,950-$30,200

Uxbridge Brook WPCP Land 

Application $3.2-$6.4MM 25-49 25%-49% 625-1,225 $5,080-$5,200

1 Compared to current phosphorus loading levels

E-29
2012 Guidelines for Water Reuse

Water Reuse in China

Authors: Allegra K. da Silva, PhD (CDM Smith) and 

Liping Lin (GE Water and Process Technologies)

China-MBR

Project Background or Rationale 

Urbanization and accelerated economic growth have 

strained water resources in China and are the key 

drivers for water reuse. Though China has the fourth 

largest fresh water resources in the world by volume, 

the distribution of this resource is dramatically uneven, 

with Northern regions of the country experiencing 

severe shortages. Because of China’s large 

population, current water resource volume per capita 

is 1.8 ac-ft (2,200 m3

), which places China 88th in the 

world in per capita water availability. As China’s 

population grows to a forecasted 1.6 billion in the mid21st century, per capita water resource will decrease 

to 1.4 ac-ft (1,760 m3

), which would result in serious 

water shortages. More than 400 cities throughout 

China face water shortages, with more than 100 cities 

facing serious water shortages, especially large cities 

such as Beijing and Tianjin. In addition to absolute 

volume shortages, environmental pollution of surface 

and groundwater sources has rendered many sources 

unfit for drinking water or industrial use. 

China has taken on the challenge of dramatically 

improving its water and wastewater infrastructure, 

making significant improvements over the past 

decade. As of 2002, the official municipal wastewater 

treatment rate was 40 percent by total volume 

produced. According to Xinhua news, as of 2010, 

China increased its municipal wastewater treatment 

rate to 75 percent (Xinhua, 2011).

Water reuse is still a minor player in the water supply 

market in China. Installations that provide reclaimed 

water mostly for industrial installations including 

cooling water, but two example installations show how 

advanced treatment will likely play a growing role in 

water reuse to help meet China’s future urban water 

needs:

1. Hohhot (capital city of Inner Mongolia province) – 

8 mgd (31,000 m3

/d) water reclamation facility to 

supply cooling water for the Jinqiao Power Plant

2. Beijing – 21 mgd (80,000 m3

/d) water reclamation 

facility to supply landscape irrigation water for 

Olympic Park, as well as water for road washing, 

toilet flushing, vehicle washing and other 

nonpotable uses

Both systems were commissioned in 2006.

Capacity and Type of Reuse 

Application 

Hohhot, located in Northern China, is dealing with 

serious water shortages. Municipal wastewater reuse 

in Hohhot is becoming more necessary and viable 

through the use of advanced treatment. In order to 

provide reclaimed water for a major water user, the 

Jinqiao Power Plant, an advanced multi-barrier 

approach was required, which uses a tertiary 

membrane bioreactor (T-MBR) system with 

ZeeWeed® MBR technology (Figure 1) and ion 

exchange. 

The Jinqiao Reuse Water Plant (JRWP) treats 8 mgd 

(31,000 m3

/d) of secondary effluent from a local 

municipal wastewater treatment plant. The high

concentration of ammonium (20-30 mg/L) present in 

the secondary effluent is targeted for removal to meet 

Figure 1

Hohhot MBR facility (Photo credit: Courtesy of GE 

Water and Process Technologies)

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

requirements for the industrial cooling water 

application. The JRWP uses a The Zee-Weed®-

membrane fiber has a nominal pore size of 0.04μm, 

which provides an absolute barrier to biomass, 

bacteria and most viruses, retaining them in the 

process tank. 

The permeate from the membrane tank is then 

pumped to a weak acid resin system for hardness 

removal and then disinfected by a chlorination system. 

The reclaimed water from the JRWP system is used 

as influent for cooling tower water supply of Jinqiao 

power plant.

As mentioned, Beijing was also facing water 

shortages. In advance of the 2008 Beijing Olympics, 

the Beijing Wastewater Group installed the Qinghe 

Reclaimed Water Plant (QRWP), a 21 mgd 

(80,000 m3

/d) MBR water reclamation facility to 

provide water for municipal uses (Figure 2). 

Approximately 75 percent of the reclaimed water from 

WRWP is used as landscape supply water for Olympic 

Park, with the remaining water supplied to municipality 

of Haidian and Chaoyang District for road washing, 

toilet flushing, vehicle washing, and other nonpotable 

purpose. The system may also provide water 

periodically to Wanquan River, Xiaoyue River, North 

Tucheng Channel and the old summer palace. 

The QRWP system includes ZeeWeed® ultrafiltration 

(UF) technology followed by an activated carbon filter. 

The operation of QRWP will play an important role in 

relieving the growing water shortage in the northern 

area of Beijing.

Water Quality Standards and 

Treatment Technology 

The Chinese central and regional governments have 

set up specific urban wastewater reuse targets, for 

example the overall reuse rate is expected to reach 20

percent for the whole country and 75 percent for 

Beijing by 2015. Technology wise, the Chinese 

government also published a series technical guidance 

(GB50335-2002, GB50336-2002, Jianke [2006] #100 

etc.) and reuse quality guidance (GB/T18919-2002, 

GB/T18920-2002, GB/T18921-2002, GB/T19772-

2005, GB/T19923-2005, GB20922-2007).

Project Funding and Management 

Practices 

Urban reuse projects could be funded by local 

government budgets (such as Qinghe through 

government owned Beijing Drainage Group), by BOT 

investors and by reclaimed water users (such as 

Huaneng Power for the Hohhot case).

Institutional/Cultural Considerations 

China’s main legislation governing water resources, 

the Water Resource Law, was revised in 2002, 

introducing water tariffs, usage quotas, and 

wastewater treatment fees. The revised law also 

opened the possibility of foreign and non-state-owned 

capital financing for public water infrastructure. Prior to 

enacting these legislative changes, the water and 

wastewater treatment industry was a commonwealth 

enterprise in China, with only limited fees levied for the 

consumption of resources and provision of services. 

The market mechanisms introduced in the revised law 

have helped to incentivize conservation and reuse, by 

creating a value for water as a resource (International 

Trade Administration, 2005). The country has 

witnessed an increase in investment in water reuse 

over the past decade as a result (Frost & Sullivan, 

2012). 

Successes and Lessons Learned

The applications described in this case study 

demonstrate how advanced technology can be applied 

to upgrade existing secondary wastewater treatment 

plants to facilitate water reuse. The use of the 

activated carbon filter was found to not be a good 

option for tertiary treatment because of rapid 

exhaustion and regeneration issues. As a result, the 

QRWP was recently upgraded to an ozone AOP 

system.

Figure 2

Beijing MBR facility (Photo credit: Courtesy of GE 

Water and Process Technologies)

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

References

International Trade Administration. 2005. “Water Supply and 

Wastewater Treatment Market in China.” U.S. Department of 

Commerce.

Xinhua. 2011. “China's municipal wastewater treatment rate 

up by 24 percentage points.” Xinhua News, March 15, 2011. 

Retrieved on March 14, 2012 at 

<http://news.xinhuanet.com/english2010/china/2011-

03/15/c_13780003.htm>.

Frost & Sullivan. 2012. “Water-stressed Chinese Industries 

Make a Beeline for Membrane Bioreactor Technology,” 

February 13, 2012. Retrieved on March 14, 2012 at 

<http://www.frost.com/prod/servlet/pressrelease.pag?docid=253494255>.

E-32
2012 Guidelines for Water Reuse

The Reuse Scenario in Bogotá

Authors: Juan M. Gutierrez, MS (Javeriana University) and 

Lucas Botero, P.E., BCEE (CDM Smith)

Colombia-Bogotá

Project Background or Rationale 

Bogotá is the capital of Colombia and the home of 

almost 10 million people. The city is upgrading and 

expanding its existing wastewater treatment to 

improve the water quality of the Bogotá River. This will 

have many benefits, including making the water quality 

suitable for reuse for agricultural irrigation. In addition, 

as the Bogotá River is used to produce 7 percent of 

the country’s energy needs through hydropower 

energy generation, improved water quality will make 

the operation significantly more efficient and safer for 

operators.

This case study illustrates how holistic water 

management planning benefits by considering reuse at 

the planning phases for wastewater treatment. 

Additionally, this is a case where water scarcity is not 

the key driver of reuse. Water reuse may be critical for 

a country with abundant freshwater resources, as 

providing water supply for dense urban populations 

drives the need to look at alternative sources for the 

various needs and uses.

Treatment Capacity and Technology 

The city’s sewer system is largely separated between 

sanitary and storm sewers, except for the old area of 

the city, which has combined sewers. The local utility 

company has been investing heavily to separate 

combined sewers. The city’s sewer system is mainly 

divided into three sewersheds: Salitre at the north, 

Fucha in the middle, and Tunjuelo at the south. 

Effluent from the entire sewer system is discharged 

into the Bogotá River. 

Early sewer master plan studies identified the need for 

two wastewater treatment plants. The first phase of the 

Salitre Wastewater Treatment Plant (WWTP) was 

constructed in the late 1990s as a chemically 

enhanced primary treatment (CEPT) process. 

Currently, the Salitre WWTP treats 91 mgd (4 m3

/s) 

with CEPT. The Salitre WWTP is in the process of 

upgrading to secondary treatment and increasing 

capacity to a projected total capacity of 167 mgd 

(7.3 m3

/s) in order to treat all wastewater from the 

north of the city. 

The second municipal wastewater treatment plant is 

the Canoas WWTP, which will be constructed by 2016. 

The Canoas WWTP is planned to treat flows from the 

remaining sewersheds, Fucha and Tunjuelo, located in 

the southern portion of the city, serving approximately 

7.2 million inhabitants. Presently, these two 

sewersheds discharge their untreated flows directly 

into the Bogotá River. The Canoas WWTP will have a 

build out capacity of 320 mgd (14 m3

/s). 

Type of Reuse Application 

There are relatively large agricultural areas located 

near the Salitre WWTP called La Ramada irrigation 

district. This district currently uses 39 mgd (1.7 m3

/s) 

for irrigation purposes, but there have been plans for 

expanding the district, resulting in the need for roughly 

114 mgd (5 m3

/s) in capacity. The water used for 

irrigation comes directly from the Bogotá River, which 

has already received a large amount of partially 

treated or untreated wastewater discharged by smaller 

towns located north of Bogotá. The existing irrigation 

infrastructure is operated by the environmental 

regional authority, Corporación Autónoma Regional 

(CAR).

Several years ago, some power agencies developed a 

hydroelectric generation scheme to use water from the 

Bogotá River, taking advantage of the river’s 3,280 ft 

(1,000 m) drop in the area south of Bogotá, before 

discharging into Colombia’s largest river, the 

Magdalena River. In fact, to enhance the water energy 

generation potential further, most of the river flow is 

currently being pumped to the Muña reservoir to allow 

the diversion of the river water through a newer 

hydropower complex. This reuse scheme provides for 

roughly 20 percent of the energy the city needs or 7

percent of the total energy required by the whole 

country. Due to this, water reuse from the Bogotá 

River is considered a national priority by the Colombia 

government and it is critical to the economic stability of 

the country.

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Figure 1 shows the main components of the Bogotá 

River wastewater treatment scheme including the 

agricultural and power generation schemes associated 

with the Bogotá River. 

In the past 5 years, the local utility company has been 

evaluating several alternatives to use wastewater 

treatment plant effluent in a different way other than 

the current energy generation. Studies by the 

Javeriana University evaluated the quality of the 

effluent water and have concluded that the effluent 

from the Salitre WWTP should be used in the near 

future as a supplementary source for the Ramada 

district, based on its proximity to the district. The 

anticipated water quality would allow restricted 

agricultural reuse after the secondary treatment is 

implemented, in accordance with Colombian water 

quality use requirements for the Bogotá River for Class 

4 usage (CAR, 2006). Though there is not current 

agricultural pressure for increased water reuse in the 

Canoas area, the plans for expanding the Ramada 

district southwardly would present a driver to reuse the 

Canoas WWTP effluent in the expanded area. This 

option has the potential benefit of relieving the existing 

Ramada district agricultural area from drawing 

excessive water out of the Bogotá River. 

Water Quality Standards and 

Treatment Technology 

As the regulating agency for the Bogotá River, CAR 

established different water quality standards for river 

water reuse. There are five different classes that range 

from reuse water for human use and agricultural use 

with or without restrictions, to energy generation and 

industrial use. Criteria for Class 4 (restricted 

agricultural irrigation) are provided in Table 1. 

Table 1 Water quality requirements for the use of 

Bogotá River water for Class 4 use (restricted 

agricultural irrigation)

Parameter Unit

Allowable 

Level

pH pH units 4.5-9.0

BOD mg/L < 50

Total coliforms MPN/100 mL < 20000

Nitrites mg/L < 10

Suspended solids mg/L < 40

Aluminum mg/L < 5

Arsenic* mg/L < 0.1

Beryllium* mg/L < 0.1

Boron mg/L < 0.3-0.4

Cadmium* mg/L < 0.01

Cobalt mg/L < 0.05

Table 1 Water quality requirements for the use of 

Bogotá River water for Class 4 use (restricted 

agricultural irrigation)

Parameter Unit

Allowable 

Level

Copper* mg/L < 0.2

Chromium (Cr+6) mg/L < 0.1

Fluoride mg/L < 1

Iron mg/L < 5

Lithium mg/L < 2.5

Manganese mg/L < 0.2

Mercury mg/L < 0.01

Molybdenum mg/L < 0.01

Nickel mg/L < 0.02

Lead mg/L < 0.1

TDS mg/L < 3000

Selenium mg/L < 0.02

Vanadium mg/L < 0.1

Zinc* mg/L < 2

* Based on CL 96/50, the concentration of an element or 

compound that produces a mortality rate of 50% in 

bioassays lasting 96 hours.

Project Funding and Management 

Practices 

Because water from the Bogotá River plays such a big 

role in Colombia’s energy generation, and the 

wastewater from Bogotá contributes up to 50 percent

of the Bogotá River average flow, the sanitation of the 

Bogotá River has become a national priority project. 

And, because there are so many different agencies 

and institutions that benefit from the river (the Bogotá 

Water and Sewer Authority–EAAB, the Colombian 

national government, CAR, the energy generation 

company, and the state of Cundinamarca), they all 

came to an agreement to fund the projects collectively. 

However, most of the projects’ funding will come from 

the national government, the CAR, and the EAAB. 

Institutional/Cultural Considerations 

The sanitation of the Bogotá River involves several 

interested parties as noted above. Since they all have 

different objectives, negotiating the project 

implementation scheme and the project funding was a 

complex process that required more than 15 years. 

Political pressures from the interested parties slowed 

down the project implementation significantly. 

Successes and Lessons Learned

Water reuse may be critical even for countries with 

abundant freshwater resources. Therefore, water 

scarcity does not necessarily drive water reuse. 

Despite political difficulties, this case shows how 

E-34
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

different entities with different objectives can join 

forces to implement water reuse projects successfully. 

Some issues that have arisen from the current 

irrigation with wastewater-impacted Bogotá River

water include increased salinity of the soils, making 

them less fertile than they were originally. 

References

Corporación Autónoma Regional de Cundinamarca (CAR). 

2006. “Acuerdo 43 de 2006 de la CAR: Clasificación 

de Usos del Agua Para La Cuenca del Rio Bogotá y 

Valores de Los Parámetros de Calidad a Aplicar 

por Clase.” Retrieved on Sept. 5, 2012 from 

<http://www.car.gov.co/?idcategoria=16034#>.

Figure 1

Components of the Bogotá River wastewater treatment scheme, showing components already constructed (red), 

under construction (grey), and planned (hatched grey). The two WWTPs, or PTARs in Spanish, are shown as 

squares (Salitre and Canoas). The Ramada irrigation district is shown in the green parallelogram in the bottom 

left-hand corner. The Muña reservoir (on the right) is the source for the hydropower complex.

E-35
2012 Guidelines for Water Reuse

Water Reuse in Cyprus

Authors: Iacovos Papaiacovou and Constantia Achileos, MSc (Sewerage Board of 

Limassol Amathus); Ioanna Ioannidou, MSc (Larnaca Sewerage and Drainage Board);

Alexia Panayi, MBA (Water Development Department); Christian Kazner, Dr.Ing.

(University of Technology Sydney); and Rita Hochstrat (University of Applied Sciences 

Northwestern Switzerland)

Cyprus-Irrigation

Project Background or Rationale 

Cyprus is the third largest island in the Mediterranean, 

measuring 150 miles (240 km) long and 62 miles (100 

km) wide at its widest point. It is located in the eastern 

part of the Mediterranean, next to the Middle East 

countries. Cyprus is the most water-stressed member 

state of the European Union with a water exploitation 

index exceeding 45 percent (AQUAREC, 2006; EEA, 

2009). At present, almost all of the renewable water 

resources in Cyprus are utilized and the amount of 

water extracted vastly exceeds natural recharge. As a 

result, in a number of areas, groundwater is being 

rapidly depleted, and sea water intrusion is occurring 

in the main coastal aquifers. Providing water for the 

expanding domestic and tourism sectors, while 

maintaining the agricultural sector, is becoming a 

critical issue.

For decades, water management in Cyprus has been 

characterized by impressive infrastructure projects to 

capture rainwater. The theme “Not a Drop of Water to 

the Sea,” Cyprus’s policy since the 1960s, was 

directed towards maximum capturing of run-off. Dam 

storage capacity increased by a factor of 50, from 

4,700 to 240,000 ac-ft (6 Mm3 to 300 Mm3

).

In 2008, after a series of dry years, the reservoirs 

dropped to unprecedented low levels and necessitated 

water supply cuts and water imports from Greece. The 

need to better adapt to aggravated water scarcity and 

drought further drives the development of water 

recycling. On the other hand, drinking water production 

is increasingly based on desalination which satisfies 

around 65 percent of the demand (WDD, 2010). 

Capacity and Type of Reuse 

Application 

In general, about 90 percent of treated wastewater is 

reused, primarily for the irrigation of agricultural land, 

parks, gardens and public greens. Most crops irrigated 

are trees such as citrus and olive or fodder crops.

A small proportion of reuse is used for groundwater 

recharge. Near the city of Paphos, the Ezousa aquifer 

is recharged artificially with 1,620 to 2,430 acre-feet 

(2-3 Mm3

) reclaimed water per year, which is reabstracted for irrigation. Investigations by 

Christodoulou (2007) showed that the aquifer would be 

able to store a total of 4,000 ac-ft (5 Mm3

) from the 

municipal wastewater treatment plant. 

Currently, the contribution of recycled water to 

irrigation water supplied through the Government 

Water Works makes up to about 10 percent of the 

demand which equals 10,500 to 12,200 ac-ft (13-15 

Mm3

). The use of recycled water was a substantial 

benefit during the extreme drought of 2008 (WDD 

2010a). After full implementation of planned schemes, 

the reclaimed water flow will amount to 48,000 ac-ft 

per year (59 Mm3

/yr) in 2012-2014 and increase 

further through 2025, as summarized in Table 1

(WDD, 2008). The annual water recycling is expected 

to use 42,000 ac-ft (52 Mm3

) by 2012-2014 which 

Figure 1

Installed dam capacity and corresponding average 

precipitation per decade (prepared from WDD 

statistics) (Hochstrat and Kazner, 2009)

E-36
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

equals 28.5 percent of today’s agricultural water 

demand (WDD, 2008a). 

Table 1 Estimated volumes of treated wastewater 

(WDD, 2008 and 2008a)

2012 2015 2025

Mm3/yr

Municipal wastewater 

treatment plants

46 51 69

Rural wastewater treatment 

plants

13 14 16

Total 59 65 85

Annual water recycling 52

Water Quality Standards and 

Treatment Technology 

Cyprus Regulation K.D.269/2005 specifies the 

reclaimed water quality criteria produced from 

agglomerations with less than 2,000 population 

equivalent. Table 2 summarizes the tiered approach 

valid for different irrigation applications. 

For agglomerations of more than 2,000 population

equivalent (p.e.), the quality characteristics (Table 3) 

and use of the treated effluent are specified within the 

Wastewater Discharge Permits, issued by the Ministry 

of Agriculture for the Sewerage Boards and the Water 

Development Department (WDD, 2008). 

The prevailing treatment technology until recently was 

conventional activated sludge treatment with 

secondary clarifiers followed by sand filtration and 

chlorination. However, most new projects under 

planning (new wastewater treatment plants as well as 

extension of existing ones) are beginning to consider 

advanced technologies such as membrane 

application, e.g. bioreactor technology (Larnaca, 

Limassol, and Nicosia) or reverse osmosis.

Project Funding and Management 

Practices 

Costs for construction and operation of municipal 

wastewater collection and treatment infrastructure are 

funded by the local communities through the sewerage 

rates. Tertiary treatment and reclaimed water 

distribution networks are financed and operated by the 

government, through the Water Development 

Department. Customers are charged different prices 

for reclaimed water depending on the end use (cf. 

Table 4 Selling rates of the treated effluent (WDD, 

2008b).

Table 2 Cyprus guidelines for irrigation urban reclaimed water from agglomerations with population less than 

2000 population equivalent (K.D.P. 269/2005)

Νο Type of Crops BOD

mg/L

SS 

mg/L

Fecal coliforms/100mlIntestinal

worms/L *** Treatmentrequired

1 All crops (a) (A) 10* 10* 5*

15** Nil Tertiary and disinfection

2 Amenity areas of

unlimited access and 

vegetables eaten 

cooked (b)

10

15** 10*

15** 50*100**

Nil

Tertiary and disinfection

3 Crops for human 

consumption and 

amenity areas of limited 

access

20*

30* 30*45** 200*1000*

Nil

Secondary, disinfection and 

storage >7 days or Tertiary and 

disinfection.

4 Fodder crops 20*

30** 30*45** 1000*5000** Nil

Secondary, disinfection and 

storage >7 days or Tertiary and 

disinfection.

(B) - - 1000*

5000** Nil Stabilization-maturation ponds with total retention time >60 days 

5 Industrial crops 50*

70** - 3000*10000** - Secondary and Disinfection

(B) - - 3000*

10000** - Stabilization-maturation ponds with total retention time >60 days

* These values must not be exceeded in 80% of samples per month (Min. number of samples = 5).

** Maximum value allowed

*** Once a year (Summer Season) (A) Mechanized methods of treatment (activated sludge etc.) (B) Stabilization ponds (a) Irrigation of leafy vegetables, bulbs and corms eaten uncooked is not allowed (b) Potatoes, beetroots, colocasia

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Table 3 Reused effluent quality characteristics 

included in the discharged permits for 

agglomerations with population above 2000 p.e.

(WDD, 2008)

Parameter

Maximum 

permitted 

value

Frequency 

of analyses

BOD5 (mg/l) 10 1/15 days

COD (mg/l) 70 1/15 days

Suspended solids (mg/l) 10 1/15 days

Conductivity (μS/cm) 2200 1/15 days

Total Nitrogen (mg/l) 15* 1/15 days

Total Phosphorous (mg/l) 10** 1/15 days

Chlorides (mg/l) 300 1/ month

Fat and oil (mg/l) 5 1/month

Zinc (mg/l) 1*** 2/year

Copper (mg/l) 0.1 2/year

Lead (mg/l) 0.15 2/year

Cadmium (mg/l) 0.01 2/year

Mercury (mg/l) 0.005 2/year

Chromium (mg/l) 0.1 2/year

Nickel (mg/l) 0.2 2/year

Boron (mg/l) 1 2/year

E. Coliforms 5/100 ml 1/15 days

Eggs of intestinal worms Nothing/l 4/year

Residual Chlorine (mg/l) 1**** 1/15 days

pH 6.5-8.5 3/week

* for discharge in sensitive areas and into the sea 

maximum level 10 mg/l

** for discharge in sensitive areas and into the sea 

maximum level 2 mg/l

*** for discharge into the sea maximum level 0.1 mg/l

**** for sensitive areas and discharge into the sea 

0.5 mg/l

Proven Benefits of Reclaimed Water 

Use

For example, the Larnaca recycling scheme 

materializes substantial benefits for the farmers.

Instead of importing silage from abroad, fodder crops 

are now produced locally with recycled water, which 

results in cost advantages of up to 1.5 million EUR per 

year. With a lack of other conventional water 

resources, this is a viable way of sustaining local 

agriculture. Acceptance of and confidence in the use 

of reclaimed water among the user group grew 

through testimonials and evident positive results for 

crop productivity (Ioannidou et al., 2011). Another 

example of increasing confidence is the case of 

Limassol, where 100 percent of reclaimed water is 

reused in agriculture, with demand not exceeding 

substantially existing supply.

Challenges 

Due to seasonal demand of water for irrigation and 

limited storage capacity, certain amounts of effluents 

are discharged to the sea during the winter months. It 

poses a challenge to establish both treatment 

technology and acceptance for utilizing these volumes 

for building up strategic reserves or restoring overpumped aquifers. In addition, treated wastewater 

standards must be revised in order to address a wider 

variety of substances of concern, such as micropollutants.

Table 4 Selling rates of treated effluent from tertiary treatment plants (WDD, 2008)

A/A Use

Existing selling Rate of 

Tertiary Treated 

Effluent 

Euro Cent/m3

Suggested selling rate of fresh not 

filtered water from governmental 

water works

Euro Cent/m3

1 a. For irrigation divisions for agricultural 

production 5 15

b. For persons for agricultural production 7 17

2 For sports 15 34

3 For irrigation of hotels green areas and 

gardens 15 34

4 For irrigation of golf courses 21 34

5 For pumping from an underground aquifer 

recharged by treated effluent 8 

6 For over consumption for items 1 to 5 Increase by 50% 56

7 

For municipal parks, green areas etc. for 

rural communities where a plant has been 

built within its limits and the quantity does 

not exceed the approved quantity of more 

than 10% 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

In view of the expected growth in wastewater 

availability and reclamation a long term Strategic Plan 

for sustainable nationwide water reuse should be 

designed and implemented. 

An Environmental Impacts Study on the Strategic Plan 

should be issued. Continuous monitoring of the quality 

and review of the standards regulating the water 

reclamation and reuse should be incorporated in the 

strategic plan. 

References

Aquarec (2006). Report on integrated water reuse concepts, 

Deliverable D19, authored by T. Wintgens and R. Hochstrat. 

Accessed on Sept. 5, 2012 from <http://www.aquarec.org>. 

Christodoulou, G.I., Sander, G.C. and. Wheatley, A.D 

(2007). Characterization of the Ezousas aquifer of SW 

Cyprus for storage recovery purposes using treated sewage 

effluent, Quarterly Journal of Engineering Geology and 

Hydrogeology 2007; Vol. 40; p. 229-240

EEA (2009) Water resources across Europe — confronting 

water scarcity and drought. EEA Report No 2/2009, 

Copenhagen, Denmark. 

Hochstrat, R. and C. Kazner (2009). Flexibility in coping with 

water stress and integration of different measures. Case 

Study Report Cyprus, Deliverable D134. Accessed on Sept. 

5, 2012 from <http://www.techneau.org>.

Ioannidou I., Theopemptou E., and Ventouris J. (2011). 

Water Reuse in Larnaca: a sustainable partner in the fight 

against water scarcity in Cyprus, 8th IWA International 

Conference on Water Reclamation and Reuse. 

K.D.P.269/2005 Ministry of Agriculture, Natural Resources 

and Environment, General Terms for the Disposal of 

Effluents from Waste Water Treatment Plants , Government 

Gazette Appendix III(I) No 4000, 3.6.2005.

WDD. (2008). Reuse of treated effluent in Cyprus. Presented 

by A. Yiannakou at the 48th ECCE Meeting, 17-18 October 

2008, Larnaca, Cyprus. 

WDD (2008a). Addressing the Challenge of Water Scarcity 

in Cyprus. Presented by Charis Omorphos at the Global 

Water Efficiency 2008, International Conference and 

Exhibition, 27-28 November 2008, Limassol, Cyprus. 

WDD. (2008b). The Implementation of the Urban Waste 

Water Treatment Directive (UWWTD) 91/271/EEC. Written 

by Ioanna Stylianou, published in ‘Agrotis’ magazine dated 

23/04/2008. 

WDD (2010) Desalination in Cyprus, presented by A. Manoli 

at the Spanish Cypriot Partnering Event, 15 March 2010, 

Nicosia, Cyprus.

WDD (2010a) Ministry of Agriculture, Natural Resources and 

Environment, Water Development Department, Water 

Demand Management. Retrieved on Sept. 5, 2012 from 

<http://www.moi.gov.cy/moa/wdd/wdd.nsf/All/E5F7AAC8FC9

9E111C2257849002ACD65/$file/Meleti.pdf>.

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2012 Guidelines for Water Reuse

Implementing Non-conventional Options for Safe Water 

Reuse in Agriculture in Resource Poor Environments

Authors: Bernard Keraita, PhD and Pay Drechsel, PhD 

(International Water Management Institute)

Ghana-Agriculture

Project Background

There is increasing water scarcity and contamination 

of water sources with untreated wastewater in urban 

environments in many low income countries (RaschidSally and Jayakody, 2008). This is because many 

cities in low-income countries lack the capacity to 

effectively collect and treat wastewater. In Ghana, 

urban vegetable farming which has been relying on 

these water sources over the years for irrigation water 

is the most affected in terms of benefits and risks. In 

many cases, farmers have no other option other than 

using the contaminated water sources for irrigation, 

which in most cases are more affordable, reliable and 

enables cultivation of vegetables throughout the year. 

Risk assessments done in major cities in Ghana 

shows high fecal contamination levels in irrigation 

water and vegetables grown with this water potentially 

leading to an annual loss of 12,000 disability adjusted 

life years (DALY) per year (Amoah et al., 2005; Razak 

and Drechsel, 2010). This is equally a concern for 

authorities who have encouraged research on safe 

irrigation practices to address the challenge, as 

recommended in Ghana’s national irrigation policy. 

Comprehensive wastewater treatment coupled with 

strict implementation of water quality standards in 

wastewater irrigated agriculture could significantly 

reduce health risks. However, this conventional 

approach is at least for now not feasible in most lowincome countries in sub-Saharan Africa, where only 

less than 1 percent of wastewater produced is treated. 

Monitoring water quality is also difficult due to the 

nature of the practice: informal, small-scale, with a 

large number of farmers spread all over cities. The 

WHO (2006) recommendation in these situations 

targets alternative, locally feasible strategies for risk 

reduction at any point between wastewater generation 

and the consumption of contaminated food. This 

multiple-barrier approach is known from the HACCP 

approach where treatment cannot meet water quality 

thresholds. 

Non-Conventional Options for Risk 

Reduction 

Some options for risk reduction, which have mostly 

been tested in Ghana, are shown in Table 1. These 

options can easily be combined for optimum reduction 

in contamination. For example, water treatment at the 

farm level can be combined with good irrigation 

techniques, better handling at markets and vegetable 

washing in households for higher cumulative reduction 

in contamination. 

Project Implementation Considerations 

A participatory approach was adopted in this study 

where key stakeholders such as urban vegetable 

farmers, vegetable sellers, street-food vendors, and 

local authorities (agriculture, health) were involved 

throughout the project. For example, farmers were 

involved in identifying most suitable options, 

developing criteria for assessment, testing them in 

their farms, while extension staff suggested materials 

for knowledge sharing.

Factors that can Enhance Adoption 

1. Identify economic or social incentives for 

behavior change: Social marketing might help 

(learning from hand wash campaigns) where 

market incentives are lacking. For farmers, tenure 

security, credit access and media recognition 

could provide incentives.

2. Enabling farmers to see and understand the 

invisible risk: If we can visualize impacts that 

safer practices could have on risk reduction, it will 

influence farmers risk perceptions and encourage 

adoption of safe practices. Microbial contamination 

cannot easily be visualized and physical indicators 

that farmers use such as smell, odor, and color 

might not necessarily correlate with microbial 

contamination. Developing parameters for routine 

monitoring will be important as laboratory 

assessments are not feasible for many of these 

farmers. 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

3. Innovative knowledge sharing: In this project, 

various initiatives were used to facilitate empirical 

knowledge exchanges between key stakeholders 

and scientists. Research findings were 

synthesized to make farmer-friendly training and 

extension materials, translated into different local 

languages and presented in various forms like 

illustrated flip charts, books, radio and video and 

demonstrated in farmer field schools and markets. 

4. Involving authorities: Local authorities and 

relevant government ministries should be involved 

from the start. In Ghana, the project involved local 

authorities, the Ministry of Food and Agriculture 

and other relevant agencies such as the food 

safety regulators. This is necessary because these 

agencies set policies and regulations for waste 

reuse, hence help in institutionalization of safe 

practices. They also have a mandate of offering 

extension services to farmers.

5. Linking with other food safety projects:

Wastewater reuse represents only one 

contamination pathway affecting farm households 

and food safety in general. For best impact, 

campaigns on safer irrigation options or vegetable 

washing in markets could be combined e.g. with 

hand-wash campaigns.

The here described activities were piloted in different 

cities in Ghana to test their feasibility but await final 

implementation.

Table 1 Non-conventional health-protection control measures and associated pathogen reductions

Control Measure

Pathogen 

Reduction 

(log units) Notes

A. Wastewater treatment 6−7 Reduction of pathogens depends on type and degree of treatment selected.

B. On-farm options

Crop restriction (i.e., no 

food crops eaten uncooked)

6−7 Depends on (a) effectiveness of local enforcement of crop restriction, and 

(b) comparative profit margin of the alternative crop(s).

On-farm water treatment:

(a) Three-tank system 1−2 One pond is being filled by the farmer, one is settling and the settled water from 

the third is being used for irrigation.

(b) Simple sedimentation 0.5−1 Sedimentation for ~18 hours.

(c) Simple filtration 1−3 Value depends on filtration system used.

Method of wastewater application:

(a) Furrow irrigation 1−2 Crop density and yield may be reduced.

(b) Low-cost drip irrigation 2−4 Reduction of 2 log units for low-growing crops, and reduction of 4-log units for 

high-growing crops.

(c) Reduction of splashing 1−2 Farmers trained to reduce splashing when watering cans used (splashing adds 

contaminated soil particles on to crop surfaces which can be minimized).

Pathogen die-off (cessation) 0.5−2

per day

Die-off between last irrigation and harvest (value depends on climate, crop 

type, etc.). 

C. Post-harvest options at local markets

Overnight storage in 

baskets

0.5−1 Selling produce after overnight storage in baskets (rather than overnight 

storage in sacks or selling fresh produce without overnight storage).

Produce preparation prior to 

sale

1−2 (a) Washing salad crops, vegetables and fruits with clean water. 

2−3 (b) Washing salad crops, vegetables and fruits with running tap water.

1−3 (c) Removing the outer leaves on cabbages, lettuce, etc. 

D. In-kitchen produce-preparation options

Produce disinfection 2−3 Washing salad crops, vegetables and fruits with an appropriate disinfectant 

solution and rinsing with clean water.

Produce peeling 2 Fruits, root crops.

Produce cooking 5−7 Option depends on local diet and preference for cooked food. 

Sources: Amoah et al. (2011).

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

References

Amoah P., B. Keraita, M. Akple, P. Drechsel, RC. Abaidoo 

and F. Konradsen. 2011. Low cost options for health risk 

reduction where crops are irrigated with polluted water in 

West Africa. IWMI Research Report 141, Colombo. 

Amoah P., P. Drechsel P, RC. Abaidoo. 2005. Irrigated 

urban vegetable production in Ghana: Sources of pathogen 

contamination and health risk elimination. Irrigation and 

Drainage 54: 49–61.

Keraita B., J. Blanca, P. Drechsel. 2008. Extent and 

implications of agricultural reuse of untreated, partly treated, 

and diluted wastewater in developing countries. CAB 

Reviews: Perspectives in Agriculture, Veterinary Science, 

Nutrition and Natural Resources 3 (058). 

Raschid-Sally L., P. Jayakody. 2008. Drivers and 

characteristics of wastewater agriculture in developing 

countries: Results from a global assessment, IWMI 

Research Report 127, International Water Management 

Institute Colombo, Sri Lanka.

Seidu, R. and P. Drechsel. 2010. Cost effectiveness analysis 

of interventions for diarrhoea disease reduction among 

consumers of wastewater-irrigated lettuce in Ghana. In: 

Drechsel P., et al. (eds.) Wastewater irrigation and health: 

Assessing and mitigation risks in low-income countries. 

Earthscan-IDRC-IWMI, UK, p. 261-283. 

WHO. 2006. Guidelines for the safe use of wastewater, 

excreta and grey water: Wastewater use in agriculture 

(Volume 2). WHO, Geneva.

E-42
2012 Guidelines for Water Reuse

Reuse Applications for Treated Wastewater and Fecal 

Sludge in the Capital City of Delhi, India

Authors: Priyanie Amerasinghe, PhD, and Pay Drechsel, PhD (International Water 

Management Institute); Rajendra Bhardwaj (Central Pollution Control Board) 

India-Delhi

Project Background or Rationale 

Based on current urbanization trends, the gap 

between water supply of 24.5 billion gallons per day 

(bgd) (95 billion liters per day [bld]) and demand of 

48.8 bgd (189 bld) is expected to increase sharply by 

2030 (McKinsey Report, 2010). Currently, 78 percent 

of the urban population in India has access to safe 

drinking water; however, only 38 percent receive 

sanitation services (CPCB, 2009). The cost of 

inadequate sanitation is estimated at $53.8 billion USD 

per year (World Bank, 2010). With a grim forecast for 

water availability and sanitation, India is exploring 

options for water saving, harvesting, recycling, and 

reuse of wastewater within cities.

The capital city of Delhi, with its population of nearly 

15 million, requires a water supply of over 1.1 bgd

(4300 million liters per day [mLd]) presently. Municipal 

sewage generation is estimated at 981 mgd (3,800 

mLd), with a treatment capacity of about 594 mgd 

(2,300 mLd). A total of 30 sewage treatment plants 

(STPs) situated in 17 locations process 61 percent of 

wastewater generated in the city at varying degrees. 

Sewage is collected and transported through a 

network of pipes and sewage pump stations, and 

treatment occurs at primary, secondary, and tertiary 

levels, depending on the design capacity.

This case study describes reuse applications of 

treated wastewater generated at the Okhla STP, and 

the utilization of its by-products by communities close 

to the city for soil conditioning and energy needs.

Capacity and Type of Reuse 

Application 

The Okhla STP is situated at Okhla, Mathura Road, 

New Delhi. Its current treatment capacity for sewage is 

164 mgd (636 mLd), and is managed by the Delhi Jal

Board (Delhi Water Board). The STP was developed in 

five phases between 1937 and 1990: 

 Phase I – 14.2 mgd (55 mLd)

 Phase II – 18.8 mgd (73 mLd)

 Phase III – 35.1 mgd (136 mLd)

 Phase-IV – 43.4 (168 mLd)

 Phase V – 52.9 mgd (205 mLd)

The treatment involves a conventional activated 

sludge process and is being managed by the Delhi Jal 

Board (DJB, 2010). A flow diagram of the water 

treatment plant, and performance evaluation of 5 

treatment units are shown in Figure 1 and Table 1, 

respectively. 

A raw sewage inlet chamber is common for all the 

units, after which liquid sewage is screened and 

conveyed to the five units for treatment. Figure 1 

depicts the key steps in the treatment process. In its 

entirety, the STP receives around 140.6 mgd (545 

mLd) of sewage at present for treatment at all five 

units. The different units have been upgraded in 

stages to optimize its capacity for treatment, and 

increase the reuse potential of its by-products.

At present, 40.8 mgd (158 mLd) of treated effluent is 

being issued to the Badarpur Thermal Power Station 

(705 MW) for cooling purposes, 23.2 mgd (90 mLd) for 

Central Public Works Department for horticulture, 11.6 

mgd (45 mLd) to Minor Irrigation Department for 

irrigation (through gravity flow), and the rest is 

discharged into Agra canal, which reaches the 

Yamuna river (dilution of pollution). The government 

departments are charged a nominal fee for 

accountability. It is estimated that over 300 farmers 

(Jaitpur area) utilize the treated water for vegetable 

(cucumber, brinjal, tomato, cabbage, raddish, green 

leafy vegetables etc.) production. Private users pay up 

to INR 1.25 for 258 gallons (1000 L) of treated water, 

which is recommended for gardening and agriculture 

only. For industrial use the charge rate currently is INR 

4.00 for 258 gallons (1000 L). At present the biogas is 

being issued to a small community living around the 

STP.

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Appendix E | International Case Studies

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Figure 1

Flow diagram depicting the wastewater treatment pathway at the Okhla STP

Excess Sludge

Untreated Grit Chamber Primary Sedimentation Tank

Aeration Tank

Sludge Drying Beds Sludge Digester Secondary Sedimentation Tank

S

c

r

e

e

n

Biogas Generation

Treated Wastewater

Sewer Network

Table 1 Performance evaluation of five sewage treatment units at Okhla STP

Phase

Capacity 

mLd

Flow 

mLd

Influent Quality Effluent Quality % Reduction

pH

TSS

mg/L

COD

mg/l

BOD

mg/l Con pH

TSS

mg/L

COD

mg/L

BOD

mg/L Con

TSS 

mg/L

COD

mg/L

BOD

mg/L

I 54.55 39.09 7.3 498 517 204 1440 7.8 21 54 10 1460 95.8 89.56 95.1

II 72.73 40.91 7.4 291 486 207 1510 7.7 83 108 48 1400 71.5 77.78 76.8

III 136.38 136.98 7.4 647 551 222 1480 7.6 76 153 45 1470 88.3 72.23 79.7

IV 168.2 159.11 7.3 480 515 249 1590 7.8 32 62 12 1540 93.3 87.96 95.2

V 204.57 181.84 7.3 480 515 249 1590 7.7 27 51 19 1530 94.4 90.1 92.4

TSS = Total suspended solids; COD = Chemical oxygen demand; BOD = Biological oxygen demand; Con = Conductivity 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

In an attempt to reduce energy costs and earn carbon 

credits, the Jal Board is also planning for power 

generation from biogas. Improved business models for 

sludge disposal are also being discussed. The Jal 

Board subjects its process management to outside 

audit to assess operational capacity and pollution 

removal efficiency. 

Water Quality Standards and 

Treatment Technology 

Treated effluent from the plant is meeting design 

standards for BOD and suspended solids, which are 

set by the Central Pollution Control Board (CPCB), as 

shown in Table 2 (CPCB, 1986).

The current percent reduction in pollution levels for 

purpose of horticulture, irrigation, and cooling is 

considered to be acceptable. The activated sludge 

process that is used for treatment is described 

elsewhere (CPCB, 2007). 

Institutional and Management 

Practices 

Installation of the Okhla STP spans over a long period 

(1937 to 1990). Infrastructure evaluation and upgrades 

have taken place at various times with funds received 

from different sources. The most recent support was 

received from USAID in 2005 for a feasibiltiy study to 

assess the reuse applications. 

Currently the Delhi Jal Board is responsible for the 

infrastructure and day-to-day operational management 

of its SPTs, treatment processes, flow measurements, 

and distribution of treated water, as well as byproducts with the support of a number of government 

and private stakeholders who serve as service 

partners. Education and awareness-raising are also a 

part of the activities of the Board, especially on the 

reuse applications. When services are provided to the 

beneficiary partners, it is advertised the public domain. 

Augmentation of the capacity of the STP is being 

considered with an additional plant at 35.2 mgd 

(136.38 mLd) under Yamuna Action Plan II, which is 

under implementation with JBIC funding.

Successes and Lessons Learned

Wastewater reuse applications are becoming popular 

among the public in part due to increased demand 

caused by shortages of water and increased domestic 

energy needs. Alternative uses for recycled water are 

recognized by government authorities (Delhi Jal Board 

and City Administration), while attempts are also being 

made to explore different treatment processes. It is 

envisaged that by popularizing alternative uses for 

treated water, the city’s drinking water supply will be 

conserved. 

However, quantitative information is not available for 

citation, presently. There is an increased demand for 

by-products like bio-gas and sludge manure, which 

can generate revenue for maintenance and upgrading 

the system. With the emergence and use of new 

technologies for reuse applications, staff training and 

capacity building in relevant institutions are important. 

At the same time, regular re-evaluation of private and 

public partnerships is also crucial. Health risk 

assessments on the use of treated wastewater, 

especially for crop production can be easily formalized, 

considering that the water quality data are available at 

the time of discharge.

Table 2 Water quality standards for India 

DO 

(mg/L) BOD (mg/L)

Total coliform 

(MPN/100 mL) pH

Free 

ammonia 

(mg/L) Conductivity SAR

Boron 

(mg/L)

Class A 6 2 50 6.5-8.5 NA NA NA NA

Class B 5 3 500 6.5-8.5 NA NA NA NA

Class C 4 3 5000 6.5-8.5 NA NA NA NA

Class D 4 NA NA 6.5-8.5 1.2 NA NA NA

Class E NA NA NA 6.5-8.5 NA 2.25 26 2 

Class A: Drinking water source without conventional treatment

Class B: Water for outdoor bathing

Class C: Drinking water with conventional treatment

Class D: Water for wildlife and fisheries

Class E: Water for recreation and aesthetics, irrigation and industrial cooling

Source: CPCB, 2000

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

References

Central Pollution Control Board (CPCB). 1986. General 

Standards for Discharge of Environmental Pollutants Part-A: 

Effluents. Retrieved on Sept. 5, 2012 from 

<http://cpcb.nic.in/GeneralStandards.pdf>. 

Central Pollution Control Board (CPCB). 2007. Evaluation of 

Operation and Maintenance of Sewage Treatment Plants in 

India. Ministry of Environment & Forests. Delhi. 

Central Pollution Control Board (CPCB), 2009. 

Status of water supply, wastewater generation, 

and treatment in Class I cities and Class II towns 

of India. Retrieved on Sept. 5, 2012 from 

<http://www.cpcb.nic.in/upload/NewItems/NewItem_153_For

eword.pdf>.

Delhi Jal Board. 2010. Retrieved on Sept. 5, 2012 from 

http://www.delhi.gov.in/wps/wcm/connect/DOIT_DJB/djb/ho

me 

McKinsey Report. 2010. India’s Urban Awakening: Building 

Inclusive Cities, Sustaining Economic Growth. McKinsey 

Global Institute, McKinsey and Company.

World Bank. 2010. Economic impacts of inadequate 

sanitation in India 2010. World Bank Water and Sanitation 

Program, New Delhi, India. Available from 

www.wsp.org/wsp/sites/wsp.org/files/publications/wsp-esiindia.pdf 

E-46
2012 Guidelines for Water Reuse

V Valley Integrated Water Resource Management: the 

Bangalore Experience of Indirect Potable Reuse

Authors: Uday G. Kelkar, PhD, P.E., BCEE, and Milind Wable, PhD, P.E. (NJS 

Consultants Co. Ltd.), and Arun Shukla (NJS Engineers India Pvt. Ltd.)

India-Bangalore

Project Background or Rationale 

To bridge the ever increasing gap between the 

demand and supply of drinking water to its customers 

in Bangalore, the Bangalore Water Supply and 

Sewerage Board (BWSSB) has plans for nonconventional solutions to increase water supply. In this 

context, based on sufficient availability of treated 

wastewater and feasibility of diverting the treated 

wastewater to indirect potable use, BWSSB initiated a 

group of “Water Recycle and Reuse” projects under 

two broad initiatives: 

1. Integrated water management in Vrishabhavathi 

Valley (V Valley) – an area of Bangalore

2. Integrated water management - lakes projects 

This case study describes the development of new 

projects in V Valley to address water requirements. 

The lake projects are not described in this case.

Under the V Valley projects, drinking water supply will 

be indirectly augmented by water reuse. Secondary

treated wastewater will be further refined through 

advanced treatment processes including membrane 

treatment and granular activated carbon (GAC) and 

discharged to a receiving river feeding a water 

reservoir that is a source for one of the drinking water 

treatment plants in Bangalore. This indirect potable 

reuse scheme will augment BWSSB’s existing water 

supply sources, which are currently insufficient to meet 

current and projected demands.

History of Water Supply in Bangalore 

Bangalore, the capital city of the state of Karnataka is 

today ranked the sixth largest city in India and is one 

of the fastest growing metropolitan cities in the world. 

The 2011 census population for Bangalore was about 

8.4 million. As Bangalore is perched on rocky strata 

without a substantial groundwater aquifer, the city 

relies entirely on surface water for supply. The 

Arkavathy River was historically the main water supply 

source for the city, providing 39.3 mgd (149 mLd) 

under two water supply schemes, the Hesarghatta and 

Tippegondanahalli (TG Halli) water supply schemes, 

which were developed in multiple stages (1896, 1957, 

1964, and 1993).

BWSSB was constituted in 1964 to provide for the 

drinking water supply and sewage disposal needs of 

the city. The Cauvery Water Supply Scheme 

implemented by the Board quadrupled the available 

piped water supplies to the city by developing the 

Cauvery River as an additional source. This scheme 

was planned in three stages (1974, 1982 and 1995). 

At the end of stage III, the total water available to 

Bangalore was 178 mgd (675 mLd). Reduction in 

rainfall duration and intensity and encroachment in the 

Arkavathy River’s catchment area has resulted in 

decline in the volume of water received in the TG Halli 

reservoir. 

Despite this dramatic overall increase in supply, the 

total present supply from both the Arkavathy and 

Cauvery Rivers, 222 mgd (840 mLd), provides a net 

per capita consumption of 26 gpd (100 Lpd), well 

below the national standard of 40 gpd (150 Lpd). To 

address shortfalls, Stage-IV of the Cauvery Water 

Supply Scheme has begun, which involves two 

phases. In Phase I, a new drinking water plant drawing 

Cauvery River water over a distance of 62 mi (100 km) 

was commissioned in 2002 to treat 79 mgd (300 mLd) 

of water. In Phase II, a new treatment plant at the 

same location is being constructed to treat 145 mgd 

(550 mLd) of Cauvery River water that is expected to 

be completed by December 2012.

In addition, eight urban local bodies and 110 villages 

around Bangalore have recently been merged forming

Bruhat Bangalore Mahanagar Palike (BBMP – Greater 

Bangalore Municipal Corporation) which has resulted 

in increase in water demand on Bangalore City. The 

progressively widening gap between availability of 

freshwater and the demand is indicated in Table 1. 

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Appendix E | International Case Studies

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Table 1 Current and projected water demand and 

availability of fresh water for the BWSSB

Year Population 

million

Demand 

MLd

Available 

mLd

Shortfall 

mLd

2001 5.4 870 540 310

2007 7.5 1219 840 379

2015 8.8 1720 15001 220

2021 10 2125 1500 615

2036 12.5 2550 1500 1050

1 In 2015, the projected available water (1500 mLd) is 

based on an increase of 148 mgd (560 mLd) which will 

be withdrawn from the Cauvery River under the Stage IV 

Phase II expansion (expected to be completed in 

December 2012). At this threshold, the maximum 

withdrawal (off take) sanctioned by the Government of 

Karnataka (GOK) is fully utilized and there will be no 

other conventional water sources to develop.

Capacity and Type of Reuse 

Application 

To address projected shortfalls, a range of solutions 

are being developed. It is feasible to harness 53 mgd 

(200 mLd) wastewater for indirect potable reuse in 

Bangalore after appropriate advanced treatment in the 

V Valley by 2015. As a first stage in the overall V 

Valley reuse scheme, 36 mgd (135 mLd) will be 

treated for reuse. Based on the technical and 

economic performance of this scheme, further 

refinements will be made and a second phase is 

planned to reuse the remaining 17 mgd (65 mLd). 

WQ Standards and Treatment 

Technology 

Under the V Valley Reuse Scheme, water that has 

gone through tertiary treatment and disinfection with 

chlorine at V Valley sewage treatment plant (STP) will 

be pumped to the Tavarekere advanced treatment 

facility. There, the water will pass through ultrafiltration 

(UF) membranes and granular activated carbon (GAC) 

adsorption filter followed by low dose of terminal 

chlorination. It is anticipated that there is not a need for 

a dechlorination facility, as chlorine concentrations are 

expected to be non-detect by the time the water flows 

through the initial portion of the engineered wetland.

However, there is a provision to add a dechlorination 

facility if chlorine levels are a problem in the future. 

This treatment scheme will achieve less than 1 mg/L 

biochemical oxygen demand (BOD) and total organic 

carbon (TOC), and below Detectable Level for fecal 

coliforms (FC) and total coliforms (TC). The highly 

Figure 1

Proposed V Valley reuse scheme (Phase 1)

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

treated water will then be discharged into the 

Arkavathy River which feeds the TG Halli reservoir.

The water will not result in polluting or degrading the 

quality of water present in the TG Halli reservoir. On 

the contrary, the quality of the TG Halli reservoir is 

likely to improve with respect to TOC and FC. This 

type of indirect potable reuse scheme follows in the 

path of similar projects around the world.

To get better understanding of what water quality is 

achievable and to understand public perception, 

BWSSB initiated a one year long pilot study 

(conducted from 2009 to 2010) that mimicked the 

actual treatment process that will be adopted for the 

full-scale plant. The pilot study included a 13,200 gpd 

(50 kL/day) membrane pilot followed by a 11,900 gpd 

(45 kL/day) GAC filter, pictured in Figure 2. 

The pilot plant data (Table 2) provided encouragement 

and clarified that indeed the water quality from this 

tertiary treated plant was superior to that of existing 

Arkavathy river water quality. 

The 2004 EPA Guidelines for Water Reuse was used 

as a guidance document in the pilot studies and 

designs, as there are currently no national or state 

treatment standards for reuse in India.

Project Funding and Management 

Practices 

Based on the pilot study data, BWSSB completed 

detailed design (30 percent completion level) to 

implement the plant on PPP mode Design Finance (60

percent) Build & Operate concept. The operation will 

be for a period of 15 years. With the design and 

bidding documents complete, BWSSB approached 

both the Government of India under the Jawaharlal 

Nehru National Urban Renewal Mission (JnNURM) for 

viability gap funding and the State of Karnataka. 

Considering the importance of the project, both the 

Governments budgeted and approved a total of 41 

million USD (2000 million rupees), which was 

equivalent to 30 percent of overall project cost. The 

remaining 70 percent would come from the Contractor 

through a PPP mode.

Table 2 Results of water reuse pilot study: Quality of water leaving V Valley STP and leaving the tertiary treatment 

plant, as compared to existing water quality in the Arkavathy River and the TG Halli Reservoir; values are averages over a 

12-month period (December 2009 – January 2010).

Concentration

Parameter

Effluent from 

secondary 

treatment 

(V Valley Plant)

Effluent from tertiary 

Treatment (Tavarekere 

Plant)1 (reclaimed water, 

which is discharged to river)

Arkavathy River 

(7 km upstream of 

Reservoir)

TG Halli Reservoir 

(values at the 

reservoir intake to

WTP)

BOD mg/L 22 1.6 12 9

COD mg/L 65 8 27 22

Sulfate mg/L 25 13 86 27

Magnesium mg/L 28 19 63 16

Phosphate mg/L 1.8 0.6 2.8 1.4

Ammonia mg/L 25 5 8 8

TDS mg/L 450 228 320 300 N/A

Fecal coliforms 

#/100 mL > 1600 2 > 1600 > 1600 N/A

E. coli MPN/

100 mL > 400 3 > 600 > 600 N/A

1 Reclaimed water that is discharged to river

N/A indicates data was not collected

Figure 2

During the pilot study, water quality testing was 

conducted

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Present BWSSB planning activities include: 

 Improvements in V Valley STP to achieve 

nutrients removal from the current volume of 36 

mgd (135 mLd), pumping of tertiary treated 

water to Tavarekere to undergo advanced 

treatment, including plans for UF and GAC 

adsorption. 

 Construction of a 36 mgd (135 mLd) capacity 

drinking water treatment plant at TG Halli (which 

draws from the reservoir) based on UF 

membrane treatment followed by reverse 

osmosis (RO) membrane treatment for a portion 

of the flow. RO is included as a provision in 

case TDS levels start increasing in the reservoir 

over time due to water reclamation. RO will be 

employed to maintain the finished water TDS 

below 500 mg/L. This phase also includes 

pumping and distribution of the drinking water 

from TG Halli to Bangalore and installation of 10 

mi (16 km) of new pipeline. 

Institutional/Cultural Considerations 

No matter how great are the technological 

advancements and availability of treatment 

technologies for advance treatment, projects tend to 

fail unless consumers have bought into the concept.

This is especially true for reuse projects due to the 

apathy of consumers towards the word “reuse.” Public 

outreach and involvement is crucial for the acceptance 

of even a very well planned reuse project. A health 

effect study to ensure the health and safety of indirect 

potable reuse must be conducted in a rigorous and 

defensible manner. 

Based on the 1-year pilot study data, BWSSB is 

planning to conduct a number of workshops and open 

discussion forums, which will not only have consumer 

participation but participation from politicians as well 

as local leaders. The workshops and public outreach 

programs were started in late 2011. In addition to this, 

BWSSB is also developing a media campaign on the 

importance of recycle and reuse and how reuse is 

beneficial to the city for its future. School kids have 

been targeted to become more active in this 

campaign.

Successes and Lessons Learned

The successful implementation of pilot plant and data 

analysis presented to decision makers helped to gain 

momentum on possibility of adding a new and first of 

its kind planned-indirect potable reuse project in 

Bangalore, India, thereby increasing the water 

availability to city of Bangalore.

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2012 Guidelines for Water Reuse

City of Nagpur and MSPGCL Reuse Project

Authors: Uday G. Kelkar, PhD, P.E., BCEE (NJS Consultants Co. Ltd) and 

Kalyanaraman Balakrishnan (United Tech Corporation)

India-Nagpur

Project Background or Rationale 

The primary goal of this project is to establish a 

wastewater recycle and reuse project in India that is 

both economically feasible and beneficial to the City of 

Nagpur as well as the Maharashtra State Power 

Generation Corporation (MSPGCL – a public sector

unit of Govt. of Maharashtra, India). The project will 

also reduce the freshwater demand for non-potable 

applications and increasing the quantity of fresh water 

available for the City of Nagpur’s use. 

Nagpur, the second capital of Maharashtra, is at the 

geographic center of India, with all major national and

state highways passing through the city. Nagpur is 

located geographically between Latitude 210 9’ North 

and Longitude 790 6’ East (Survey of India Top sheet 

No. 55 O/4) at an altitude of 1017 ft (310 m) above 

MSL. The soil type around Nagpur is mostly black 

cotton with very high fertility and rich in organic 

contents. Major cash crops are orange, cotton, 

sugarcane, and chili. Maximum, average, and

minimum rain fall values are 78 in (1990 mm), 47 

inches (1200 mm) and 24 inches (600 mm) 

respectively. The maximum temperature reaches 118 

degrees F (47.8 degrees C) in May and minimum is 43

degrees F (6 degrees C) in mid December.

The current population of Nagpur is 2.35 million. The 

city presently receives freshwater from three different 

sources, the Kanhan River, Pench River and 

Gorewada reservoir tank, for a total of 124 mgd (470 

mLd) of water at the rate of 35-40 gallons/cap./day 

(135-150 L/cap./day) . At present, 124 mgd (470 mLd) 

of water supply in the city generates about 100 mgd 

(380 mLd) (approx. 80 percent recovery) of sewage 

that is partially treated and discharged into natural 

water courses – drains and Nallas. 

Maharashtra State Power Generation Corporation 

(MSPGCL, formerly known as MSEB) has two existing 

thermal power stations (TPS) to the north of Nagpur 

City at a distance of about 7 miles (12 kilometers). 

One TPS of 840MW capacity is at Khaperkheda, and 

the other TPS of 1100MW is at Koradi. The power 

stations are approximately 1 mile (1.5 km) away from 

each other. Due to growing power demand by the 

State of Maharashtra, MSPGCL has planned for three 

new power stations – one at Khaperkheda and two at 

Koradi, each with 500MW capacity. Coal linkage for 

the proposed power stations was established earlier 

and MSPGCL was in the process of securing water 

linkage for the power stations. MSPGCL had the 

existing allocation from Pench River for 45,000 ac-ft/yr

(55 Mm3

/year). With the addition of three new power 

stations, MSPGCL was looking for a total additional 

water requirement of 47,000 ac-ft/yr (58 Mm3

/year) 

starting in 2015, when the new power plants come online. The existing percent consumption of water for 

various uses at the power station is shown in Figure 1. 

Following a request from MSLGCL, the Irrigation 

department of Government of Maharashtra, increased 

the water allocation of 45,000 ac-ft/yr (55 Mm3

/year) to 

54,000 ac-ft/yr (67 Mm3

/year) with a max. to 60,000 

ac-ft/yr (75 Mm3

/year) within 10 percent variation). 

However, this was projected to be insufficient for all 

three units, and there was no additional freshwater 

allocation available for MSPGCL from any other 

source.

Figure 1

Percent consumption of water by type of use for the 

power station

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Project Funding and Management 

Practices 

To resolve the issue of water availability for MSPGCL, 

USAID, through its project titled Water Energy NEXUS 

Phase - II (WENEXA - Phase II), initiated a feasibility 

study that included demand assessment and 

evaluation of alternate water sources, including but not 

limited to use of high quality tertiary treated water from 

the city of Nagpur’s wastewater plant. The project also 

implemented a six month long pilot plant (Figure 2) to 

showcase achievable output water quality and get buyin from both Nagpur Municipal Corporation (NMC) as 

well as MSPGCL that reuse is effective and feasible. 

The pilot plant was constructed by M/s. Triveni 

Engineering and Industries Ltd., using Memcor/

Siemens ultrafiltration unit that received secondary 

treated wastewater from the NMC’s existing 

Bhandewadi STP.

The pilot study also helped gain public acceptance as 

well as support from State Government of 

Maharashtra, which issued a policy paper on reuse of 

wastewater for non-potable applications as a means of 

conserving freshwater for the city.

The water quality requirements, when compared with 

the tertiary-treated wastewater quality from the pilot 

plant and existing fresh water quality from the Pench 

Reservoir, indicated that the reclaimed water can be 

used for a number of applications at the power plant, 

including ash handling without further treatment, and 

can be used for cooling tower with the addition of a 

disinfectant. Based on the pilot plant study, the total 

reuse potential at the plant by 2015 was determined to 

be 69,000 ac-ft/yr (84.64 MM3

/yr) (Figure 3).

Comparative assessment between the available fresh 

water sources and reuse water indicated that 

MSPGCL can construct the reuse plant by 2014 at a 

capital cost of 2000 million rupees (200 Crores – 10 

million equal to 1 Crore) while the cost of constructing 

a new dam and construction of new pipeline from a 

fresh water source could cost 3500 million (350 

Crores) rupees and could take more than 10 years to 

get completed as the construction of new dam would 

have to go through various requirements and 

clearances through Ministry of Environment and Forest 

(MOEF) and address the issue of submergence and 

re-settlement of farmers. In addition, with the lower 

capital cost, the reuse project showcases an 

environmental friendly solution, solving NMC’s 

wastewater treatment and discharge issues. 

Based on the study results, pilot plant data and the 

potential for getting good quality reclaimed water in 

short period of time, MSPGCL signed a Memorandum 

of Understanding (MOU) with Nagpur Municipal 

Corporation (NMC) in support of NMC’s Water Reuse 

Project, and to supply treated water from municipal 

sewage plant as the water linkage to meet additional 

demand of Mahagenco’s proposed expansion plan. In 

addition, MSPGCL agreed to pay NMC 150 million

rupees (15 crores) every year for the next 15 years as 

royalty fee. In addition, MSPGCL agreed to construct a 

new sewage treatment plant with tertiary treatment 

capability with the capability to pump the treated water 

to its thermal power stations. Based on this 

agreement, NMC being a municipality, approached the 

central Government and received a grant for a sum of 

800 million rupees towards the project under the 

Jawaharlal Nehru National Urban Renewal Mission 

(JnNURM), while the remainder of the cost 1200

million rupees will be borne by MSPGCL. 

Figure 3

Total reuse potential at the power plant for ash 

handling and cooling water make-up by 2015

Figure 2

Pilot setup for Nagpur water reuse scheme

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Institutional/Cultural Considerations 

The use of pilot plant data and results were helpful in 

getting both government officials and the public at 

large to get acceptance for the use of reclaimed water 

for non-potable applications. In addition to conducting 

pilot studies, the team also conducted a number of 

workshops and willingness surveys. The results of 

these activities helped the Government of Maharashtra 

to develop a policy paper in support of water reuse 

(Figure 4). 

Successes and Lessons Learned

Based on the USAID study, public workshops, and 

pilot plant results, the project was finalized. The full 

scope of the project is given in Table 1: 

The project is now under contract finalization with the 

selected contractor, who will have to construct the 

plant and other ancillary parts in a 24 month period 

and then operate the plant over the next 10 years as 

part of an operation and management contract. 

Table 1 Scope of Work for Nagpur Reuse Scheme

Sr. 

No. Module Description

1 A Construction of Kolhapur type 

collection weir, intake structure, sump 

and pump house, and miscellaneous 

works

2 B Construction of sewage treatment plant 

(for primary and secondary treatment)

3 C Construction of micro filtration tertiary 

treatment plant

4 D Construction of tertiary water sump, 

pump house, transmission main up to 

Koradi 8.60 Kms, storage tank at 

Korado, and other miscellaneous 

works

5 E Interconnectivity arrangement from 

Bhandewadi, i.e., sump, pump house, 

transmission main up to Pioli Nadi 7.62 

Kms or up to Koradi T.P.S.

References

Design Report and Bid Documents – submitted to MSPGCL 

on Koradi Reuse Project, NJS Consultants Co. Ltd., 2010. 

Detailed Project Report (DPR), Nagpur Recycle and Reuse 

Project, Submitted to JnNURM Govt. of India for Grant 

Funding, 2008.

Water Energy Nexus (WENEXA-II), USAID Report “Water 

Reuse Options and Pilot plant Study for Greater Nagpur 

municipal Corporation(NMC) – PA Consulting Group and 

CDM, 2007.

Figure 4

Government of Maharashtra published a written policy 

paper in support of water reuse

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2012 Guidelines for Water Reuse

Managing Irrigation Water with High Concentrations of 

Salts in Arid Regions

Authors: Alon Ben-Gal, PhD, and Uri Yermiyahu, PhD (Agricultural Research 

Organization, Gilat Research Center, Israel); Sirenn Naoum, PhD, Mohammad Jitan,

PhD, Naeem Mazahreh, PhD, and Muien Qaryouti, PhD (National Center for Agricultural 

Research and Extension, Jordan)

Israel/Jordan-Brackish Irrigation

Project Background or Rationale 

Agricultural development of the Middle East is 

contingent upon use of high amounts of low-quality 

irrigation water. Available water sources for irrigation, 

including reclaimed wastewater, often contain high 

levels of salts, including ions specifically toxic to plants 

such as sodium (Na) and boron (B). 

Under a study made possible through support 

provided by The Middle East Regional Cooperation 

Program, US Agency for International Development, 

Grant M24-014, water management, both in terms of 

leaching requirements (water applied to remove salts 

from root zone) and in terms of understanding crop 

response to stress conditions caused by salinityexcess B combinations, was evaluated. Ultimately the 

results of this investigation provided growers with 

decision making tools for irrigation with low-quality 

water under arid conditions.

Capacity and Type of Reuse 

Application 

Field and lysimeter experiments were conducted in 

arid regions of Jordan and Israel to investigate the 

response of vegetable crops, irrigated with saline 

water, to irrigation levels and to elevated 

concentrations of B. The experiments included bell 

pepper (Capsicum annum), melon (Cucumis melo L.), 

green beans (Phaselous vulgaris L.), and tomatoes 

(Lycopersicon esculentum). Water application rates 

were studied in greenhouses at the Al-Karameh 

experimental station in the mid Jordan Valley. For 

each crop, four irrigation water rates were used (80, 

100, 120 and 140 percent return of potential 

evapotranspiration ETp). Irrigation water had electrical 

conductivity (EC) of 2.4 dSm-1. In Israel, salinity-water 

combinations were investigated in studies on bell 

pepper in the Arava Valley. Tomatoes and peppers 

were evaluated for salinity-B interactions. For peppers 

in Jordan, irrigation water had B solutions at 

concentrations of 0.046, 0.37, 0.74, and salinity levels 

of 5, 15, 25, and 35 millimolar (mM) NaCl. Tomatoes in 

Israel were irrigated with water having EC of 1, 3, 6, 

and 9 dS m-1 and B levels of 0.028, 0.185, 0.37, 0.74, 

1.11, and 1.48 mM. 

The project utilized state-of-the-art lysimeter facilities 

in Jordan (Karameh) and in Israel (Gilat, Arava Valley). 

In addition to growth and yield, data collected included 

actual plant-scale transpiration and amount and quality 

of water leached out of the root zone, thus facilitating 

environmental as well as agronomic and economic 

considerations.

Water Quality Standards and 

Treatment Technology 

The quality of water in experiments was designed to 

represent across-the-scale expected qualities of 

reclaimed municipal wastewater. Salt and B 

concentrations in wastewater are mostly a function of 

their concentrations in background water and additions 

from human sources. Typical wastewater treatment, 

up to tertiary processes, does not remove dissolved 

salts. Less intensive treatments schemes (aeration 

ponds) actually concentrate these salts due to 

evaporation. Only desalination would remove or 

reduce salinity and such treatment of wastewater is 

currently considered highly uneconomical. 

Leaching Requirements

When salinity is negligible, yield increases as a 

function of increased application of water to a crop, up 

until the point that the demand for evapotranspiration 

is satisfied. When salts are present, they depress 

water uptake and growth and therefore, additional 

water application is accompanied by a positive yield 

response. The mechanism for this is leaching of salts 

from the soil and maintenance of relatively salt-free 

environment for root activity. 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Figures 1 and 2 show that while total yield is limited 

by source water salinity and sensitivity of the crop, as 

salinity increases, so does the marginal effect of 

increasing water application rate over ET 

requirements. In other words, when the water is salty, 

higher application means higher yield. In Figure 1, 

Relative total biomass production of peppers (Yield 

normalized to maximum yield) is graphed as a function 

of irrigation application level for three irrigation water 

salinity (ECIW) levels. Symbols are experimental 

measurements from two seasons (open symbols fall, 

closed symbols spring) and lines are results from an 

analytical model (Ben-Gal et al., 2008; Shani et al., 

2007) The results from this figure show that the 

highest yields reached with non-saline water are 

impossible when salts are present but can be 

approached—under the condition that leaching 

requirements are satisfied. 

Figure 2 displays fruit yield of three crops grown in 

Jordan irrigated with increasing rates of brackish 

(EC = 2.4 dSm-1 water) where ETp is potential 

evapotranspiration). Pepper is more sensitive to 

irrigation water salinity than melon which is more 

sensitive than beans as seen in slopes of water 

response curves in Figure 2 as application over 100

percent ETp is reached.

Salinity-boron interactions

Tomato and pepper were found to have decreased 

plant growth, yields and transpiration in response to 

either boron (Figure 3) or salinity. Figure 3 shows Dry 

Matter (DM) g plant-1 accumulation in organs of bell 

pepper (Capsicum annum.cv. Saphir) as affected by 

soil boron in Karameh Jordan.

A number of modeling approaches were applied to 

experimental results to investigate the nature of 

salinity-boron interactions on crop production. For both 

tomatoes and peppers, an antagonistic relationship for 

excess B and salinity was found (Figure 4). In other 

words, toxic effects on growth and yield were less 

severe for combined B toxicity and salinity than what 

would be expected if effects of the individual factors 

were additive. (Ben-Gal and Shani, 2002; Yermiyahu 

et al, 2008).

Figure 3

Dry matter (DM) g plant1 accumulation in organs of 

bell pepper

Figure 2

Fruit yield of three crops grown in Jordan

Figure 1

Relative total biomass production of peppers

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Figure 4 presents biomass production of tomatoes as 

a function of boron in irrigation water for varied salinity 

conditions where EC is electrical conductivity of 

irrigation water. Symbols shown in the figure are 

experimental measurements, Yotvata, Israel, lines 

depict dominant factor modeling approach (Ben-Gal 

and Shani, 2002).

Project Funding and Management 

Practices 

This work was made possible through support 

provided by The Middle East Regional Cooperation 

Program, US Agency for International Development, 

Grant M24-014. 

Institutional/Cultural Considerations 

Irrigation water salinity decreases transpiration and 

biomass production of horticultural crops. The extent 

of the salinity response is dependent upon the level of 

leaching of salts from the root zone. Application of 

saline water to the soil exceeding the quantity used by 

the crop for transpiration, succeeds in improving 

conditions for water uptake and growth (Figures 1, 2, 

5). The addition of such water has higher relative 

benefit as the salinity of the water and the sensitivity of 

the crop increase. Lysimeter, field, and modeled 

experimental results in dry regions of Jordan and 

Israel suggested that potential economic benefits from 

increased yields exist for irrigation application rates 

reaching more than 200 percent of the ETp for a high 

value but relatively salt sensitive crop like bell pepper. 

Leaching fractions were seen to increase as a result of 

reductions in transpiration caused by increases in 

salinity. 

Decision making by growers benefits from 

consideration of soil-crop-climate specific predictions 

of yield as a function of irrigation water quality and 

quantity (Figure 5). For example, a farmer in the 

Jordan Valley irrigating with EC 3 water cannot expect 

to reach greater than 70 percent of the potential yield 

for a pepper crop even with exorbitant rates of water 

application. By choosing a more tolerant melon crop, 

the farmer can achieve 90 percent of potential yield 

with the same water that yielded 70 percent peppers. 

Figure 5 presents a compensation presentation of Isoyield curves for irrigation water salinity (EC) and 

applied irrigation water quantity relative to climate 

demand (I Tp-1) for pepper and melon crops. Curves 

were computed using the ANSWER model (Shani et 

al., 2007). Isolines show 10 percent increases in 

relative yield.

Successes and Lessons Learned

This investigation found that irrigation of horticultural

crops with brackish water can be economically feasible 

as long as sufficient excess water is applied to control 

root zone conditions.

It was also found that the combined effects of 

simultaneous high salinity and excess boron were less 

than those predicted by combining the expected 

individual effects of each stress causing factor. This 

opens the door for utilization of water sources that 

otherwise would be considered unacceptable. 

In spite of these successes, the results indicate that 

irrigation with saline water under arid conditions is 

problematic. Sustainable cultivation must provide for 

collection and disposal of the leached salts and water 

Figure 5

Compensation presentation of Iso-yield curves for 

irrigation water salinity

Figure 4

Biomass production of tomatoes

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

or alternatively, reduce the leaching. Reduced 

leaching is only possible through cultivation of highly 

tolerant crops or via the reduction of water salinity prior 

to irrigation (Ben-Gal et al 2008, Shani et al., 2007). In 

the case of wastewater reuse, it may be preferable to 

reduce salinity and boron in source water, prior to its 

reaching the wastewater stream, and long before its 

use for irrigation, rather than loading the environment 

with these problematic salts. Many sources of B 

(detergents, sea water) can be avoided or treated in 

source water using available legislative and 

technological tools. Desalination technology is 

becoming increasingly attractive and offers an elegant 

way to remove salts in source (municipal) water where 

they can be best managed and to leave agriculture 

with water that will lead to higher yields and lower 

environmental impact (Ben-Gal et al., 2009). 

References

Ben-Gal A, Ityel E, Dudley L., Cohen S, Yermiyahu U, 

Presnov E, Zigmond L, Shani U. 2008. “Effect of irrigation 

water salinity on transpiration and on leaching requirements: 

A case study for bell peppers”. Agric. Water Manag. 95, 587-

597.

Ben-Gal A., and Shani, U. 2002 “Yield, transpiration and 

growth of tomatoes under combined excess boron and 

salinity stress”. Plant Soil, 247, 211-221.

Ben-Gal A. Yermiyahu U. and Cohen S. 2009. “Fertilization 

and blending alternatives for irrigation with desalinated 

water”. J Environ. Quality. 38:529-536.

Shani, U., Ben-Gal, A. Tripler E. and Dudley, L.M. 2007. 

“Plant response to the soil environment: an analytical model 

integrating yield, water, soil type and salinity”. Water 

Resources Res. Vol. 43, W08418, 10.1029/2006WR005313

Yermiyahu U., Ben-Gal A., Keren R. and Reid R.J. 2008. 

“Combined effect of salinity and excess boron on plant 

growth and yield”. Plant and Soil. 304, 73-87.

E-57
2012 Guidelines for Water Reuse

Irrigation of Olives with Recycled Water

Authors: Arnon Dag, PhD; Uri Yermiyahu, PhD; Alon Ben-Gal, PhD; and Eran Segal, PhD

(Agricultural Research Organization, Gilat Research Center, Israel) and Zohar Kerem, 

PhD (The Hebrew University of Jerusalem, Israel) along with colleagues from the 

Association for Integrated Rural Development, West Bank and the National Center for 

Agricultural Research and Extension, Jordan

Israel/Palestinian Territories/Jordan-Olive Irrigation

Project Background or Rationale 

There is increasing use of low quality water for olive 

grove irrigation in the Mediterranean, due to scarcity of 

fresh water.

The aims of the present study were: 1) to evaluate the 

effect of irrigation with recycled wastewater (RWW) on 

tree growth, fruit, and oil yield and quality; 2) to assess 

the contribution of RWW to plant nutrition and; 3) to 

quantify nitrate and chloride losses when using RWW. 

Capacity and Type of Reuse 

Application 

A 4-year field study comparing two olive cultivars, 

Barnea and Leccino, was conducted within a 20 ha 

commercial high density (900 trees/ha) olive orchard. 

Three treatments were tested: A) fresh water with 

standard fertigation (drip irrigation using water 

amended with fertilizer (potassium and nitrogen), B) 

RWW with standard fertigation, and C) RWW with 

reduced fertigation (accounting for the potassium and 

nitrogen available in the RWW). The RWW was 

secondary-treated domestic wastewater from the City 

of Jerusalem and fresh water originated from the local 

costal aquifer. Water composition is presented in 

Table 1. Annual average irrigation application was 

470 mm (18.5 inches). The total annual amount of 

nutrients arriving with the RWW were substantial, 

equaling some half of the recommended fertilization 

dosages. 

Diagnostic leaves sampled in July each year were 

tested for macro elements and salts. Trunk 

circumference was measured once a year. Upon 

reaching the appropriate ripeness level, fruit was 

harvested and yield, fruit size, water, and oil content 

were measured. Oil was extracted, tested for free fatty 

acid content, peroxide level and polyphenol content, 

and evaluated for organoleptic attributes by a trained 

panel. 

Table 1 Composition of fresh water and RWW. Values 

represent the 4-year average and standard deviation 

(2006-9, n=18)

Constituent Units RWW Fresh 

Water

pH 7.7 (0.3) 7.5 (0.2)

EC ds m-1 1.65 (0.13) 0.9 (0.2)

NH4-N 4.8 (6.8) 0.0 (0.0)

NO3-N 15.2 (3.9) 3.4 (2.2)

Total N 19.9 (6.0) 3.4 (2.2)

K mg L1 29.6 (2.2) 4.4 (2.8)

P 5.8 (1.8) 0.0 (0.0)

Cl 323 (30) 168 (56)

Na 198 (25) 81 (28)

SAR 4.9 (0.8) 4.2 (1.9)

Results 

Diagnostic leaves. Mineral concentration in diagnostic 

leaves serves as a benchmark for salinity and 

nutritional status of olive trees. The measured 

concentrations of N, P, and K in the leaves obtained 

from trees receiving the three treatments were within a 

range considered normal (Therois, 2009), indicating 

adequate nutritional status across the treatments. 

There were no significant differences in leaf 

concentration of Na and Cl across the treatments, 

indicating that the additional application of these 

elements from RWW application did not accumulate in 

leaves. 

Tree growth, fruit and oil yield. For both cultivars in 

each year, no significant differences were found 

between treatments for the parameters: trunk 

diameter, fruit number, average fruit weight oil content, 

water content, fruit yield, and oil yield. Fruit from 

“‘Barnea” trees had higher oil content (ranging from 

19.2 to 26.6 percent) than “‘Leccino”’ (ranging from 

17.8 to 20.5 percent). Multiplying olive fruit yield by oil 

content provided oil yield per tree which ranged from 

4.6 to 9.3 lb (2.1 to 4.2 kg) (1686-3372 lb/ac or 1890-

3780 kg/ha) in the “‘On” years (2006, 2008) in 

“Leccino.” The “Barnea” trees had similar oil yields, 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

ranging from 4.4 to 9.7 lb/tree (2.0 to 4.4 kg/tree) 

(1606-3533 lb/ac or 1800-3960 kg/ha).

Oil quality. Oil quality (free fatty acid level, polyphenol 

content and peroxide level) did not differ significantly 

among the treatments. Organoleptic assessments to 

grade the oil taste (bitterness, pungency and 

fruitiness) did not reveal any negative attributes in any 

of the tested oils. In respect to positive attributes, 

fruitiness and pungency were similar among the 

different treatments. Bitterness, on the other hand, 

was much lower (~ 1 on a 10-point scale with 10 being 

a very intense taste) in oil obtained from trees 

receiving RWW with standard fertigation (condition B) 

compared to oil from trees receiving fresh water 

(bitterness level of 6.5) (control condition). However, 

this effect was reduced when the fertigation regime 

was adjusted (condition C), with bitterness value 

reduce to 5. 

Bacteriological tests. Total bacteria count in the RWW 

was 17,000 per 100 ml and <1 for the fresh water. No 

Salmonella bacteria were found in the two types of 

water. No differences were found between bacteria 

counts in oil obtained from trees irrigated with fresh 

water and those irrigated with RWW water. 

Soil salinity. While similar amounts of water were 

applied, the RWW treatments loaded the soil profile 

with 1.75 times more Cl then the fresh water 

treatment. Additionally, significantly more nitrates were 

transported out of the root zone in the RWW with 

standard fertigation in comparison to the RWW with 

reduced fertigation and fresh water treatments for both 

cultivars. This implies that consideration of nutrients 

originating with the RWW is vital for its sustainable 

utilization. 

The result of this experiment, together with our 

previous findings on negative effects of over 

fertilization on productivity (Erel et al., 2008) and oil 

quality (Dag et al., 2009), have inspired the olive 

experts of Israel’s agricultural extension service to 

adjust their fertilization recommendations. The new 

recommendations take the amount of N and K in the 

RWW into account when planning fertilization regimes.

Project Funding and Management 

Practices 

The research was supported by grant M26-062 of the 

USAID Middle East Regional Cooperation Program, as 

well as by grant 203-0620 from the Chief Scientist of 

the Israeli Ministry of Agriculture and Rural 

Development. 

Institutional/Cultural Considerations 

Due to overall scarcity of water in Israel, water 

available for irrigation of olive orchards is limited to 

recycled wastewater and brackish groundwater. In the 

past, some sectors restricted use of RWW due to 

religious objections, but the necessity for water 

combined with modernization and education have 

overcome these and other obstacles for utilization of 

recycled water across all sectors. Consumers in Israel 

generally do not object to the use of RWW. The 

opposite is actually the case, as water recycling is 

perceived as “green” and promoting resource 

conservation. Moreover, the people in Israel are 

keenly aware that fresh water is very scarce and tend 

to object its allocation to the agricultural sector.

Successes and Lessons Learned

Irrigation of olives with RWW did not affect tree 

nutritional status, growth, productivity or oil quality. 

RWW can be used safely with no negative effects on 

the oil produced, but fertilization regimes need to be 

adjusted in order to consider nutrients delivered with 

RWW to avoid negative effects of over fertilization. In 

this way, contamination of water resources from 

nutrient leaching can be minimized and the RWW can 

provide an additional benefit from reduced fertilizer 

costs (Segal et al., 2011). 

References

Dag, A., Ben-David, E., Kerem, Z., Ben-Gal, A., Erel, R., 

Basheer, L. and U. Yermiyahu. 2009. Olive oil composition 

as a function of nitrogen, phosphorus and potassium plant 

nutrition. Journal of the Science of Food and Agriculture. 88: 

1524-1528. 

Erel, R., Dag, A., Ben-Gal, A., Schwartz, A. and U. 

Yermiyahu. 2008. Flowering and fruit set of olive trees in 

response to nitrogen, phosphorous, and potassium. Journal 

of the American Society for Horticultural Science 133: 639-

647.

Segal, E., Dag, A., Ben-Gal, A., Zipori, I., Erel, R., Suryano, 

S. and U. Yermiyahu. 2011. Olive orchard irrigation with 

reclaimed wastewater: Agronomic and environmental 

considerations. Agriculture, Ecosystem and Environment, 

140: 454-461. 

Therois, I. 2009. Olive. Crop production science in 

horticulture no. 18 Cabi, MA.

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2012 Guidelines for Water Reuse

Advanced Wastewater Treatment Technology and Reuse 

for Crop Irrigation

Author: Josef Hagin, PhD, and Raphael Semiat, PhD (Grand Water Research Institute

Technion – Israel Institute of Technology, Haifa, Israel)

Israel/Jordan-AWT Crop Irrigation

Project Background

Shortage of water in sub-humid and semi-arid regions 

like the southeast Mediterranean, leads to use of 

wastewater for agricultural irrigation. Most of the 

effluent used is derived from secondary wastewater 

treatment plants or from sources having even lower 

water quality. Secondary-treated wastewater still 

contains some pathogens, organic compounds, and 

salts. Irrigation with this water induces, in a shorter or 

longer term, increased soil salinity that damages soils 

and crops. Sustainable agricultural production requires 

high water quality. Membrane treatment is a promising 

technology for the environmentally friendly removal of 

pollution agents and for rendering wastewater into a 

resource for unlimited use (J. Hagin et al., 2007; and J. 

Hagin et al., 2010). This project was carried out as a 

collaboration between researchers from the Technion 

– Israel Institute of Technology, Al-Quds University in 

Jerusalem, and the National Center for Agricultural 

Research and Extension in Jordan.

Application of Membrane Technologies 

Advanced membrane treatment technologies based on 

ultra filtration (UF) and two stage reverse osmosis 

(RO) yield effluent of suitable quality for unrestricted 

irrigation.

Operation of the UF, mainly flow rate and water 

recovery, was monitored continuously. Steady UF 

performance required weekly cleaning by a NaOH 

solution, periodic acidic (HCl) cleaning for removal of 

inorganic scaling and backwash cycles. The operation 

included chlorination of the UF feed as an antibiofouling agent, followed by dechlorination of the 

permeate prior to entering the RO membranes, to 

prevent damage.

During the lengthy operation, changes in quality of the 

secondary effluent (organic matter and suspended 

solids) resulted in parallel decrease of UF 

performance. Adjustments of the filtration-backwash 

cycle compensated fully for the performance decrease. 

This showed the system's ability to operate at varying 

and reduced feed quality. 

Water recovery from the UF system was up to 88

percent. Recycling the rejected UF concentrate to the 

feed tank contributed an additional 6-9 percent to the 

UF water recovery. The UF operated at a flux of 93.78 

gallons/ ft2

/hr (33 l/m2/hr) and the permeability was 

about 0.89 gallons/ft2

/psi/hr (40 l/m2/bar/hr).

The first RO stage (RO1) receives the UF permeate. It 

operated at a feed rate of about 1,717 gallons/hr (6.5 

m3

/hr) under 88.2 psi (6 bar) pressure, at a recovery 

ratio of about 50 percent, and a pH of 6.5. Osmotic 

backwash is executed automatically every 60 minutes 

by shutting down the pressure pump for 1 minute. 

Scaling, organic fouling, and phosphate precipitation 

were negligible.

The second RO stage (RO2) received the RO1 brine. 

The RO2 membrane feed rate is about 607.6 

gallons/hr (2.3 m3

/hr), 449.1 gallons/hr (1.7 m3/hr) 

fresh feed (RO1 brine), and the rest is recycled 

concentrate operated at a pressure of 102.9 psi (7 bar) 

and a pH of 6.5. Osmotic backwash is automatic, the 

same as for the RO1 membrane.

Measurements indicated a long-term reduction in RO2 

membrane performance. Calculations of mass balance 

showed that 33 percent of the inflow phosphate and 15

percent of the calcium were precipitated on the 

membrane. The pH control was not sufficient for

steady operation, and chemical precipitation was 

required. Phosphate in the RO1 brine precipitated on 

the RO2 membrane as a complex calcium-phosphate. 

Phosphate removal was achieved by injecting ferric 

chloride into the RO1 brine pipe, forming a solid 

strengite—FePO4.2H2O, thus preventing its 

precipitation on the membrane (Katz and Dosoretz, 

2008).

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The RO2 stage extracted additional water from the 

rejected brine stream of the RO1 stage and its addition 

improved total system recovery to up to about 85

percent. 

The overall operational cost of the pilot plant, following 

the process improvements, is estimated at $0.55-

0.60/m3

. 

Crop Irrigation with Treated 

Wastewater

Secondary treated effluents, permeates of RO and 

mixtures of RO and UF membranes permeates were 

used for irrigation on a number of crops on several 

Palestinian, Jordanian and Israeli sites. 

Irrigation using secondary-treated effluent induced 

significantly higher soil salinity, expressed as electrical 

conductivity (EC), than RO permeate, or UF and RO 

permeates combined (Tables 1 and 2). In addition, 

increased dripper clogging was noted.

In experiments running for several years at the same 

site, a significant decrease in crop yield was measured 

in plots irrigated by secondary-treated effluent 

compared to those irrigated by membrane-treated 

water (Table 3). 

Biological tests of membrane treated irrigation water 

did not show any fecal coliform contamination.

Table 1 Electrical conductivity (EC) in soil, Jordanian site after 2 seasons of irrigation 

Irrigation water quality

Depth (cm) Sec. treat. effluent UF permeate Mix UF-RO 

50-50

EC (dS/m)

0-20 3.24 2.83 1.14 

20-40 3.01 2.71 0.99 

Table 2 Electrical conductivity (EC) and Sodium adsorption ratio (SAR) values in soil samples after 6 years 

irrigation with various water streams, Arad site, Israel

Water Quality: Sec effl. UF permeate UF-RO

70-30

UF-RO

30-70 RO permeate

EC, dS/m 16 9 6 5 2

SAR 25 20 16 12 3

Table 3 Crop yields (tons per hectare) for plots irrigated with different blends of reclaimed water at 

the Arad site, Israel

Irrigation Water Watermelon Garlic Corn grain

Sec. treat. effluent 28 24 7.8 

UF permeate 36 30 10.7 

UF- RO 70-30 34 30 10.1 

UF- RO 30-70 44 32 10.3 

RO permeate 50 37 11.3 

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Measurement of pharmaceuticals, aspirin, 

paracetamol, X-ray contrast media, diatrizoate and 

carbamazepine and their degradation products, 

showed their complete removal by RO membranes.

Successes and Lessons Learned

The project’s results provide guidelines for large-scale, 

economically and technically feasible operation of 

wastewater treatment systems, regional and 

worldwide. They indicate the potential of adding a 

substantial amount of quality water (up to 600,000 m3

) 

to the regional resources for irrigation and aquifer 

recharge. The overall conclusion and recommendation 

to water authorities, for maintaining an adequate water 

supply to agriculture and ensure production 

sustainability, is to construct membrane systems on a 

large scale at secondary treatment sites in the entire 

region.

Project Funding

The project is a cooperative Palestinian-JordanianIsraeli project, coordinated by the Grand Water 

Research Institute, Technion and generously 

supported by the U.S. Agency for International 

Development – MERC Program, the Peres Center for 

Peace and other foundations.

Institutional/Cultural Considerations 

The project created an excellent basis for PalestinianJordanian-Israeli cooperation. Over the years, 

professional and personal ties have developed 

between the investigators. Investigators at the 

participating institutes acquired a deeper 

understanding and greater experience regarding the 

processes and performances of membrane systems. 

This makes them experts in consulting authorities for 

large-scale wastewater treatment systems. 

References

Katz, I. Dosoretz, C.G. (2008). Desalination of domestic 

wastewater effluents: phosphate removal as pretreatment. 

Desalination 222, 230-242.

Hagin, J. Oron, G. Fardous, A.N. Boulad, A. Haddad, M. 

Khamis, M. Ben Hur, M. (2007). Wastewater treatment and 

reuse in agricultural production. Final Report submitted to 

the USAID – MERC, Project M22-006 and Semi – Annual 

Reports 2003 – 2007

Hagin, J. Khamis, M. Bulad, A. Al Hadidi, L. Oron G. (2010). 

Advanced wastewater treatment technology and reuse. Semi 

– Annual Report submitted to USAID – MERC, Project M28-

028 and Semi – Annual Reports 2008/2009.

Hagin, J. Khamis, M Manassra, A Abbadi, J Qurie, M Bulad, 

A AlHadidi, L Semiat, R Shaviv, A Katz, I Dosoretz, C 

Blonder, O (2010) Treatment and use of wastewater for 

agricultural irrigation. Proceedings International Fertiliser 

Society 680, UK.

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2012 Guidelines for Water Reuse

Treatment of Domestic Wastewater in a Compact Vertical 

Flow Constructed Wetland and its Reuse in Irrigation

Authors: Ines Soares, PhD; Amit Gross, PhD; Menachem Yair Sklarz, PhD; Alexander 

Yakirevich, PhD; and Meiyang Zou, MSc (Ben Gurion University of the Negev, Israel); 

Ignacio Benavente, Eng, PhD; Ana Maria Chavez, Eng, MSc; Maribel Zapater, MSc; and 

Diana Lila Ferrando, Eng, MSc (Universidad de Piura, Peru)

Israel/Peru-Vertical Wetlands

Project Background or Rationale 

The quantity of freshwater available worldwide is 

declining, and there is a pressing need for alternative 

sources, such as reuse of treated wastewater. In 

heavily populated areas, the most common strategy to 

treat domestic wastewater (DWW) for disposal or 

reuse is via intensive, centralized, often sophisticated 

and expensive systems. This approach is often 

unsuitable in developing countries, in lightly populated 

areas, or on remote farms where on-site 

(decentralized) treatment by low-cost low-tech

systems should be considered. Treatment by 

constructed wetlands (CW) is recognized as an 

economically favorable option, even in the most 

developed countries (IWA, 2000).

Reuse of treated DWW for irrigation may involve 

certain risks of soil pollution due to salinization, boron 

accumulation, hydrophobicity (e.g., caused by 

detergents), pathogens and other pollutants. 

Particularly in on-site scenarios, variability in water 

quantity and quality might negatively impact treatment 

efficiency. Thus, any treatment system has to address 

these issues and consistently produce effluents that 

comply with defined quality guidelines.

In our approach to decentralized DWW treatment and 

reuse in irrigation we have developed a small footprint 

CW (Figure 1) — the recirculating vertical flow 

constructed wetland (RVFCW) (Gross et al., 2008; 

Sklarz et al., 2009; Zapater et al., 2011). The diversity 

and dynamics of the RVFCW bacterial community 

were analyzed to enhance our understanding of the 

treatment efficiency and stability (Sklarz et al., 2011), 

and a mathematical model that can be used as a tool 

to design and operate these systems was formulated 

(Sklarz et al., 2010). Lastly, possible effects of 

irrigation with RVFCW effluent on soil properties were 

assessed (Sklarz, 2009). This research was carried 

out in Israel at the Zuckerberg Institute for Water 

Research at Ben Gurion University of the Negev.

Two similar 130 gallon (500 L) RVFCWs were used in 

the study. The systems consist of a three-layer bed (a 

thin upper-layer of organic soil planted with 

macrophytes, a middle thicker layer of high surface 

porous medium, and a thin lower-layer of limestone 

gravel) and a reservoir located beneath the bed. 

Wastewater is introduced in batches to the bed, 

percolates through it and trickles down into the 

reservoir, allowing for passive aeration; from the 

reservoir the water is recirculated back to the bed with 

a small pump until the effluent quality meets the 

relevant regulation (i.e., according to its use and the 

country standards). 

Prior to irrigation, the treated DWW passes through a 

standard 130-micron filter to prevent clogging of the 

irrigation system and enhance the efficiency of the 

subsequent UV disinfection treatment. The high 

oxygen levels in the water allow for the conversion of 

nitrogen in the DWW to nitrate and minimize its loss, a 

Figure 1

Schematic representation of the field RVFCW

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2012 Guidelines for Water Reuse

desirable added value in that it lowers the need for 

crop fertilizer (Table 1). 

Table 1 Quality of the raw DWW after primary 

sedimentation and of the RVFCW effluent after 6 h 

of treatment. Values shown are the arithmetic 

mean values (except where noted as geometric 

mean) and standard errors for samples from July 

2007 to March 2008.

Parameter (mg L-1) 

Raw 

(influent) 

Mean (SE)

Effluent 

Mean (SE) 

Israeli 

Standard*

TSS 103 (11) 6.8 (1.0) 10

BOD5 178 (19) 6.2 (0.9) 10

COD 200 (13) 18 (2.6) 100

TN 36 (2) 27 (1.1) 25

NH4

+

-N 29 (2.4) 1.3 (0.4) 20

NO2

-

-N BD** 0.62 (0.1)

NO3

-

-N 0.3 (0.0) 23 (0.9)

DO 0.2 (0.1) 8.2 (0.2)

pH 7.4 (0.0) 7.6 (0.1)

EC (mS cm-1) 0.96 (0.1) 0.94 (0.1) 1.4

E. coli 

(CFU 100 mL-1) 1×106 5.4*** 10

*Unrestricted irrigation (Inbar, 2007)

**Below detection

***Geometric mean

An irrigation experiment was conducted in which 

barrels 32 gallon (120 L) were filled with a naive sandy 

loamy soil and irrigated daily, at a rate of 2.6 gpd (10 

l/d) , with one of four types of water: fresh water (FW), 

FW amended with 7:3:7 (N:P:K) fertilizer (FW+F), 

settled raw-DWW and RVFCW-treated-DWW after UV 

light disinfection. No further treatment was applied to 

the soil. Periodically, 20-inch (50-cm) deep soil cores 

were removed and analyzed. After three years, the 

physicochemical characteristics (pH, electrical 

conductivity, organic and water contents, and macroand micro- elements) and bacterial community of the 

soil irrigated with the treated DWW were similar to 

those of the soils irrigated with FW+F but differ from 

soils irrigated with raw-DWW (data not shown). This 

may imply changes in the biochemical processes in

the soil irrigated with raw-DWW. 

The treatment efficiency under extreme variations in 

quality of the DWW was tested in a set of experiments 

using 8 gallon (30 L) bench-scale systems. In this 

study we assessed the resilience and recovery 

capacity of the RVFCW upon exposure to possible 

disturbances, which included high and low water pH, 

interruption of water recirculation, and high 

concentrations of E. coli, surfactants (i.e., detergents) 

and bleach. The effects of these disturbances were 

short-lived and recovery was observed within 24 

hours, attesting to the robustness of the RVFCW (data 

not shown).

Capacity and Type of Reuse 

Application 

The RVFCW is modular, enabling more units to be 

attached, serially or in parallel. Thus, the system can 

be up-scaled to serve a small community or a 

neighborhood. The required water quality will dictate 

the DWW load and the retention time, as well as the 

recirculation rate. Interestingly, the experimental 

results demonstrate that the size of the unit does not 

significantly affect the system’s efficiency (Sklarz et al., 

2010). Different volumes were treated in the different 

experiments, ranging from 0.03 to 4 m3

/d (80 to 1,060 

gpd). A typical hydraulic load is 0.5 m3

 m-2 d-1 and the 

retention time to meet high water quality standards for 

unrestricted DWW reuse in irrigation (Inbar, 2007) is 

about 5 hours, which corresponds to potential organic 

load capacity of over 270 g COD m-2 d-1 and 120 g 

BOD5 m-2 d-1. 

Water Quality Standards and 

Treatment Technology 

When treated with the UV disinfection unit, the effluent 

of the RVFCW consistently met the stringent Israeli 

standards for reuse in irrigation of <10 CFU E. coli 100 

mL-1 (Inbar, 2007).

Project Funding and Management 

Practices

Funds from Ben-Gurion University of the Negev and 

USAID supported this research.

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Institutional/Cultural Considerations 

Based on the pilot results, the RVFCW was chosen for 

installation in two low-income Bedouin communities.

The first, designated “Project Wadi Attir,” aims to 

develop and demonstrate a model for sustainable, 

community-based organic farming, adapted to a desert 

environment (The Sustainability Laboratories, n.d.).

The treated wastewater will be used for unrestricted 

landscape and possibly fodder irrigation. Construction 

has started and the site is expected to start operating 

during 2012. In the second community, installation of 

several units is planned in the Egyptian Bedouin 

village of St. Catharine in the Sinai desert (funding is 

expected via a UN project). The initiation of this project 

is unclear due to the current political situation in Egypt. 

The water will be used for unrestricted irrigation mainly 

of the local fruit trees and gardens. The choice of the 

RVFCW was interesting, considering the electricity 

requirements for recirculation in places where 

electricity is often scarce and not always reliable. The 

use of solar energy could be an alternative, should 

electricity supply become problematic. The justification 

for using the RVFCW, and not gravity-based systems, 

was the high treatment efficiency, the low 

maintenance, and the low footprint, particularly 

important in areas with high evaporation rates. 

Moreover, two-dozen units have been installed by 

private households throughout Israel for onsite 

graywater reuse, and have been operated successfully 

for more than three years for unrestricted ornamental 

garden irrigation. 

Successes and Lessons Learned

We demonstrated that it is possible to safely reuse 

DWW by simple low-cost low-tech treatment means. 

The system design must consider the unique 

conditions associated with on-site DWW reuse, such 

as high variability in water quality and quantity, and 

exposure to short events of extreme conditions. The 

system can produce treated DWW of very high quality 

for unrestricted reuse such as for urban, agriculture 

and landscape irrigation. 

References

Gross, A., M. Y. Sklarz, A. Yakirevich and M. I. M. Soares. 

2008. “Small scale recirculating vertical flow constructed 

wetland (RVFCW) for the treatment and reuse of 

wastewater”. Water Science and Technology 58(2):487-494.

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, pp. 291-296.

IWA, Specialist Group on Use of Macrophytes in Water 

Pollution Control. 2000. Constructed Wetlands for Pollution 

Control. IWA Publishing, London. 

Sklarz, M. Y. 2009. Development and Optimization of a 

Recirculating Vertical Flow Constructed Wetland for 

Treatment of Domestic Wastewater. PhD thesis, Ben-Gurion 

University of the Negev, Israel.

Sklarz, M. Y., O. Gillor, A. Gross, A. Yakirevich and M. I. M. 

Soares. 2011. “Microbial diversity and community 

composition in recirculating vertical flow constructed 

wetlands.” Water Science and Technology 64(11):2306-

2315.

Sklarz M. Y., A. Gross, M. I. M. Soares and A. Yakirevich. 

2010. “Mathematical model for analysis of recirculating 

vertical flow constructed wetlands.” Water Research

44:2010-2020.

Sklarz, M. Y., A. Gross, A. Yakirevich and M. I. M. Soares. 

2009. “A recirculating vertical flow constructed wetland for 

the treatment of domestic wastewater.” Desalination

246:617-624.

The Sustainability Laboratories. n.d. “Project Wadi 

Attir - Model Sustainable Desert Community.” 

Retrieved on Sept. 6, 2012 from 

<http://www.sustainabilitylabs.org/page/project-wadi-attirmodel-sustainable-desert-community>.

Zapater M., A. Gross and M. I. M. Soares. 2011. “Capacity of 

an on-site recirculating vertical flow constructed wetland to 

withstand disturbances and high variable influent quality.”

Ecological Engineering 37:1572-1577. 

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2012 Guidelines for Water Reuse

A Membrane Bioreactor (MBR) Used for Onsite 

Wastewater Reclamation and Reuse in a Private Building 

in Japan

Author: Katsuki Kimura, Dr.Eng., and Naoyuki Funamizu, Dr.Eng. 

(Hokkaido University, Sapporo, Japan)

Japan-Building MBR

Project Background or Rationale 

In Japan, about 2,500 urban buildings reuse 

wastewater and harvest roof runoff for various 

purposes. In several large cities including Tokyo, 

regulations require a wastewater reuse system or a 

runoff harvest system to be installed in a new building 

if the total floor area of the building exceeds a certain 

size. A sample of 2,500 buildings with reuse/harvest 

systems found that 25.9 percent are public office 

buildings, 12.5 percent are private office buildings, and 

15.7 percent are schools. Reclaimed wastewater 

and/or harvested rainwater are used for a variety of 

purposes. The water is most commonly used for toilet 

flushing, but can also be used for landscape irrigation, 

cooling, car cleaning and fire protection.

A treatment system for wastewater reclamation in an 

individual building should be compact, easy to 

maintain and resistant to fluctuation of inflow. Low 

production of odor and sludge is also an important 

requirement for such a system. Membrane bioreactors 

(MBRs) can meet these criteria and are therefore often 

used for onsite wastewater reclamation. An example of 

an MBR system used for onsite wastewater 

reclamation/reuse system in a private building is 

shown (Figures 1 and 2). 

Capacity and Type of Reuse 

Application 

The MBR system was installed in a business complex 

building in Tokyo in 2007. Treatment capacity of the 

system is 180,000 gallons per day (680 m3

/day) and 

reclaimed water is used solely for the purpose of toilet 

flushing. Wastewater reclaimed for toilet flushing 

includes graywater from restaurants, graywater from 

offices, and blowdown from a cooling tower system. 

Black water from the toilet is not recycled and is 

prohibited by regulations. Figure 3 presents the flow of 

water in the wastewater reuse system.

Figure 1

A business complex building in Tokyo in which the 

MBR system was installed (Photo credit: Drico. Ltd.)

Figure 2

View of the MBR system installed (Photo credit: Drico. 

Ltd.)

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Treatment Technology 

Both hollow fiber membranes and flat-sheet 

membranes can be used in MBRs. Due to the ease of 

maintenance, flat-sheet membranes are often 

preferred in applications to small-scale systems such 

as onsite wastewater reclamation. The MBR system in 

this study used 1,800 flat-sheet membrane elements 

submerged in the reaction tank. The material of the 

membrane is chlorinated polyethylene with a nominal 

pore size of 0.4 μm. 

Compared to the MBRs used in municipal wastewater 

treatment (i.e., large-scale treatment), mixed liquor 

suspended solids (MLSS) concentration in the reactor 

tends to be higher (15-20 g/L) in the case of MBRs 

used for onsite wastewater treatment. Graywater from 

restaurants contains substantial amounts of oil/grease, 

which can cause operational problems in MBRs. Thus, 

this heavily contaminated graywater is treated by 

sequencing batch reactors (SBRs) before being mixed 

with the other wastewater. Effluents from MBRs are 

used for toilet flushing only after the addition of 

chlorine, as mandated by the government. 

In this particular MBR in Tokyo, they use activated 

carbon adsorption to remove color from the reclaimed 

water before the chlorine is added. Conditions of the 

system (e.g., trans-membrane pressure in the MBR) 

are continuously monitored by an automatic system.

Water Quality 

Quality requirements for reclaimed water used for toilet 

flushing are summarized in Table 1. The averaged 

data obtained with the system are shown in Table 2. 

Design water quality in the effluent from the treatment 

system is also shown in the parenthesis in Table 2. It 

should be noted that quality of wastewater in Table 2

represents the mixture of graywater from offices, 

blowdown from the cooling tower system, and effluents 

from the SBRs treating restaurants wastewater.

Table 1 Quality requirements for reclaimed water used 

for toilet flushing

Parameter Requirement

pH 5.8-8.6

Odor Not abnormal

Color and transparency Almost colorless and 

transparent

E. coli Must not be detected

Residual chlorine (mg/L) 0.1 (free)

0.4 (combined)

BOD (mg/L) <20

COD (mg/L) <30

Table 2 Water quality observed in the treatment system

Parameter

Raw 

Wastewater Effluent

pH 6-8 7.7 (6-8)

Odor Not abnormal

E. coli Not detected

BOD (mg/L) 215 <1.0 (<10)

SS (mg/L) 215 <1.0 (<5)

n-Hex (mg/L) 43 <1.0 (5)

Color (color unit) 4 (<10)

Turbidity (turbidity unit) <1 (<2)

Project Funding 

The regulations for the construction of new buildings 

require a wastewater reuse system or a runoff harvest 

system to be installed. This policy driven water reuse 

intervention places the financial burden on the project 

developer.

Successes and Lessons Learned

The customer is satisfied with the net reduction of 

domestic water supply. Performance of the MBR 

system has been satisfactory as shown in Table 2. 

Operation and maintenance of the MBR were found to 

be very easy. Withdrawal of sludge and chemical 

cleaning of the membrane were carried out every 30 

days and every 4 months, respectively, and have been 

sufficient to maintain stable operation of the system. 

When possible, use of graywater from restaurants as a 

source for reclamation should be prevented because 

Figure 3

Wastewater reuse system flow diagram

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of the difficulty in treatment. Unfortunately, the amount 

of “clean” graywater produced in the building is not 

sufficient to cover the amount needed for toilet 

flushing. To fill the gap, graywater produced in 

restaurants is also included as the source of reclaimed 

water at the cost of pretreatment.

References

Public Building Association. 2005. Design of wastewater 

reclamation and rainwater harvest systems (in Japanese). 

Kimura, K., Mikami, D. and Funamizu, N. 2007. “Onsite 

Wastewater Reclamation and Reuse in Individual Buildings 

in Japan.” In: Proceedings of 6th Conference on Wastewater 

Reclamation and Reuse for Sustainability, Antwerp, Belgium, 

October 9-12, 2007.

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2012 Guidelines for Water Reuse

Water Reuse and Wastewater 

Management in Jordan

Authors: Bader Kassab, MSc (USAID Jordan) and Ryujiro Tsuchihashi, PhD (AECOM)

Jordan-Irrigation

Introduction 

Water management has long been recognized as one 

of the most critical issues for the sustainability of the 

Hashemite Kingdom of Jordan. According to Jordan's 

Water Strategy (2009), the country's annual per capita 

water availability is less than 40,000 gallons per year 

(150 m3

/yr). Available water supply is less than 

demand, and with continuing population growth, per 

capita availability is projected to continue declining in 

the coming years. 

Jordan's Water Strategy states that "Wastewater is not 

managed as ‘waste’ but is collected, treated, 

managed, and used in an efficient and optimized 

manner." Beneficial use of reclaimed water is 

recognized as a crucial water management component 

and controlled use of reclaimed water has grown 

significantly during the past decade. 

Institutional Arrangement and 

Regulations 

The use of treated municipal wastewater is regulated 

through the water reuse standard JS893:2006, issued 

by the Institution for Standards and Metrology. The 

current standard was issued in 2006, replacing 

previous standards from 1995 and 2002. The 

standards allow irrigation of agricultural crops that will 

not be eaten raw. The standards also specify 

requirements for the use of reclaimed water for 

groundwater recharge to the aquifer not connected to 

drinking water sources, but planned groundwater 

recharge with reclaimed water has not yet been 

implemented in Jordan. The use of reclaimed water for 

other purposes such as cooling and fire fighting is 

permitted on a case-by-case basis, when confirmed 

with appropriate studies. Water reuse is planned 

concurrently with the construction of wastewater 

treatment plants. The Water Authority of Jordan (WAJ) 

is responsible for the management of the water and 

wastewater systems and for managing the supply of 

treated effluent for reuse purposes. 

Promoting Water Reuse Practice 

WAJ has been contracting with farmers to provide 

them with reclaimed water for agricultural irrigation; 

larger scale sites of this kind include As-Samra, 

Madaba, Ramtha, Akeder, and Mafraq, among others. 

As of 2009, about 1,900 acres (760 hectares) are 

irrigated with reclaimed water under contracts with 

WAJ. 

As-Samra, located approximately 19 miles (30km) 

northwest of Amman, is the largest wastewater 

treatment plant in Jordan, with 70 mgd (267,000 m3

/d) 

treatment capacity. A lagoon treatment system was 

built in 1985, and replaced by an activated sludge 

plant with partial funding from USAID. The new plant 

came online in 2008 to provide better effluent quality. 

As of 2008, the treatment plant received approximately 

58 mgd (220,000 m3

/d) (MWI, 2010), and treated 

effluent is discharged to the Zarqa River, which flows 

into the King Talal Reservoir where it is mixed with 

surface water. The water from the reservoir is used for 

irrigation in the Jordan Valley for various food crops 

including vegetable crops, citrus and bananas. 

It is worth noting that fodder crop irrigation is the 

dominant application for all other water reuse schemes 

in Jordan, with the exception of trees such as date 

palm and olive. This is partly due to the high 

dependency on imported livestock feed. It is also due 

to the reluctance of farmers to use reclaimed water for 

food crops that may be exported to neighboring 

countries as those countries may have some 

reservations about importing such crops. 

Water Reuse Project Case Study 

USAID has been supporting the efforts to promote 

water reuse in Jordan. The water reuse pilot project at 

Wadi Mousa is an example of a USAID-funded project 

that promotes sustainability of local communities 

through the beneficial use of reclaimed water.

A demonstration pilot program for the use of reclaimed 

water for irrigation was first established in Wadi Mousa 

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2012 Guidelines for Water Reuse

in 2002 as a 17 acres (6.9 ha) demonstration site at 

the time of the Wadi Mousa wastewater treatment 

plant (WWTP) upgrade; it was later expanded to 

approximately 90 acres (37 ha) to include the use of 

reclaimed water by a local community. The wastewater 

treatment plant has a treatment capacity of 0.9 mgd 

(3400 m3

/d) and consists of preliminary treatment 

(coarse screen and grit removal), activated sludge 

(oxidation ditch), final clarifiers, polishing ponds and 

disinfection. Effluent from the treatment plant is 

transferred to the irrigation water storage pond within 

the WWTP boundary, and reclaimed water is 

distributed through an irrigation water pump station 

and an irrigation water distribution main. As of 2010, 

the plant inflow is approximately 0.5 mgd (2000 m3

/d). 

Reclaimed water quality is routinely monitored by the 

plant engineer and consistently meeting Jordanian 

Standards for all reuse applications.

During the USAID Reuse for Industry, Agriculture and 

Landscaping Project (RIAL: 2004-7), the pilot program 

was further expanded, and reclaimed water was used 

to irrigate alfalfa, olive, fruit trees and other tree crops. 

The pilot has been operated by the Sad Al-Ahmar 

Association, a water reusers' association established 

in 2002 with the support of USAID to ensure 

sustainability of the project. Currently, the association 

is operated with support from the Hashemite Fund for 

the Development of Jordan Badia (HFDB). The 

Association represents the local community, from 

which 40 farmers (34 men, six women) work directly 

with the pilot program. Each farm unit was allocated 

0.75 to 1.1 acres (0.3 to 0.45 ha), and cropping 

patterns were identified with the technical support of 

the project team. The pilot program demonstrated that 

reclaimed water use can be practiced safely and 

introduce stable income into local communities. By the 

winter of 2006-7, total area used for reclaimed water 

irrigation was over 130 acres (52 ha), and the net 

income per farm ranged from $3100 to $4600 per 

year, depending on the type of crops irrigated (in 2007 

dollars; RIAL Completion Report: 2008). The net 

income accounted for the costs of maintaining the 

Association and the irrigation system. Alfalfa was the 

dominant crop grown with reclaimed water; olive trees 

were also grown at the pilot site. Most of the harvested 

olives were consumed by the farmers; indirect 

economic benefits to farmers were achieved through 

the reduction in their food expenses.

The RIAL project also demonstrated the beneficial use 

of reclaimed water for landscaping and industry in 

Amman and Aqaba. In Aqaba, reclaimed water has 

been used for industries (mainly cooling for potash 

operations) and the city's landscaping areas. Aqaba 

WWTP, constructed by USAID funds, consists of a 

lagoon treatment train and tertiary treatment process 

with oxidation ditch, clarifier, filtration and disinfection. 

Reclaimed water from the lagoon system is used for 

agricultural irrigation, whereas tertiary-treated 

reclaimed water is used for landscape irrigation and 

industrial applications. The industrial use provided 

mutual economic benefits for both Aqaba Water 

Company (which will finance the system after the 

conclusion of USAID’s funding period) and the 

industry, and saved about 1,200 ac-ft/yr or 400 

Mgal/year (1.5 million m3

/year) of fresh water that 

could then be dedicated for domestic and commercial 

uses. A pilot program was also established at the 

Jordan University of Science and Technology (JUST) 

to investigate the effects of reclaimed water irrigation 

on various agricultural crops and landscaping plants. 

Plans to support additional water reuse schemes are 

underway with various USAID Office of Water 

Resources and Environment projects, including the 

Water Reuse and Environmental Conservation Project. 

Currently the focus is to promote efficient reclaimed 

water irrigation to promote income generation for local 

communities, and industrial water management and 

pollution prevention through the integration of efficient 

use and reuse of water in industrial sectors. An 

analysis of lessons learned from previous 

demonstration projects will be used to establish 

sustainable and self-sustaining programs for the 

livelihood enhancement of local communities.

References

MWI (2010). Ministry of Water and Irrigation Annual Report, 

Ministry of Water and Irrigation, Amman.

MWI (2009). Water for Life, Jordan's Water Strategy 2008-

2022, Ministry of Water and Irrigation, Amman. 

Task 1 Completion Report (2008) USAID Reuse for Industry, 

Agriculture and Landscaping project. 

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2012 Guidelines for Water Reuse

Cultural and Religious Factors Influence Water Reuse

Author: Tom A. Pedersen (CDM Smith)

Jordan-Cultural Factors

Project Background or Rationale 

Although global water resources are theoretically 

adequate to meet all human needs, water scarcity is 

the reality for many in arid and semi-arid areas around 

the world. When freshwater supplies are insufficient to 

meet ecosystem and human demand, water stress or 

water scarcity results. According to the United Nations 

(2007), water stresses occurs when the water supply 

drops below 450,000 gallons per person per year 

(gallons/person/yr) [1,700 cubic meters per person per 

year (m3

/person/yr)], and water scarcity results when 

supplies drop below 264,170 gallons/person/yr (1,000 

m3

/person/yr). Further, the United Nations (2007) has 

estimated that 40 percent of the world’s population will 

live in water scarce regions of the globe by 2025. Per 

capita water supply in Jordan is expected to fall to 

24,040 gallon/person/yr (91 m3

/person/yr) by 2025 

should the current population growth trend be 

maintained putting Jordan in the category of having 

an absolute water shortage (Hashemite Kingdom of 

Jordan Geography and Environment, 2012). 

Maplecroft (2012) ranks the Hashemite Kingdom of 

Jordan as 10th among the 17 countries in the world 

having extreme water risk as measured by their water 

stress index. The index is based on the ratio of 

domestic, industrial, and agricultural water 

consumption, against renewable supplies of water 

from precipitation, rivers, and groundwater.

Jordan is undertaking aggressive programs to address 

its current and future water needs and key among 

these is the use of treated wastewater effluent in 

agricultural production. Cultural and religious factors 

have been shown to have significant bearing on the 

success of wastewater reuse projects in Jordan, as in 

other Islamic cultures.

Culture and Religion 

As stated in Water – The Epic Struggle for Wealth, 

Power, and Civilization, “Everyone understands that 

water is essential to life. But many are only just now 

beginning to grasp how essential it is to everything in 

life – food, energy, transportation, nature, leisure, 

identity, culture, social norms, and virtually all the 

products used on a daily basis. With population growth 

and economic development driving accelerated 

demand for everything, the full value of water is 

becoming increasingly apparent to all.” (Solomon, 

2010)

The World Bank (2012) reports that wastewater use in 

agriculture is increasing especially in areas of water 

scarcity, increasing population, and where demand for 

food is on the rise. The expanding recognition of 

wastewater has nutrient value along with irrigation 

value is leading to increased acceptance for use in 

agricultural production. Although wastewater can be a 

reliable source of irrigation water, the World Health 

Organization (WHO) cautions that wastewater is 

always a public health risk and WHO Guidelines for 

the Safe Use of Wastewater, Excreta and Greywater 

(2006a) employ an approach integrating risk 

assessment and risk management to control waterrelated diseases.

The WHO guidelines recognize that in addition to 

technical issues, cultural and religious factors are 

important to the success of wastewater irrigation 

practice. WHO reports that societal concerns related to 

use of untreated human excreta range from 

abhorrence to acceptance (WHO, 2006b). In Africa, 

the America’s and Europe excreta use is generally 

regarded with “disaffection,” whereas in Asia its use is 

accepted and in keeping with Chinese and Japanese 

“traditions of frugality.” In Islamic societies however, 

direct contact with excrement is abhorred however its 

use after treatment would be acceptable if the 

treatment were to remove impurities. Further, in 

Islamic countries it has been judged that wastewater 

can be used for irrigation provided that the impurities 

present in raw wastewater are removed (WHO, 

2006a). 

Islamic Fatwas 

Fatwas are Islamic religious rulings of a scholarly 

opinion on a matter of Islamic law issued by a 

recognized religious authority in Islam (About Islam). A 

fatwa is based in knowledge and wisdom and those 

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2012 Guidelines for Water Reuse

issuing the fatwas must supply evidence from Islamic 

sources for their opinions. However, it is not 

uncommon for scholars to come to different 

conclusions regarding the same issue. WHO (2006a) 

cites the 1978 Council of Leading Islamic Scholars of 

Saudi Arabia issuing a fatwa concerning the use of 

wastewater in Islamic Societies which stated “Impure 

wastewater can be considered as pure water and 

similar to the original pure water, if its treatment using 

advanced technical procedures is capable of removing 

its impurities with regard to taste, colour and smell, as 

witnessed by honest, specialized and knowledgeable 

experts.”

The following question was posed to the World Fatwa 

Management and Research Institute website in 2007: 

“From the Islamic point of view, is the reuse of treated 

wastewater permissible for irrigation of crops or park 

areas?” The response reads in part: “If water treatment 

restores the taste, color, and smell of unclean water to 

its original state, then it becomes pure and hence 

there is nothing wrong to use it for irrigation and other 

useful purposes” (INFAD, 2012).

Jordan RIAL Projects 

The United States Agency for International 

Development’s (USAID) Reuse in Industry, Agriculture 

and Landscaping (RIAL) projects have engaged 

farmers in the successful use of treated wastewater in 

agricultural production. The projects have been 

successful because they have addressed not only 

technical and economic, but institutional and cultural 

issues as well (USAID, 2008). The RIAL projects 

pioneered the first Water User Association (WUA) in 

Jordan for operation, maintenance and management 

of a wastewater-based irrigation system and the 

introduction of urban wastewater use for the first time 

Jordan. 

The Wadi Mousa WUA is comprised of women and 

men who work together on developing cropping 

patterns and schedules, equitable water distribution 

agreements, and utilize commonly-owned machinery 

and equipment. WUA pay their water fees to sustain a 

viable, independent, and productive irrigation system 

and they work with system operators and with the 

Petra Regional Authority in planning new activities 

(Abu Awwad, 2006). 

The RIAL projects have shown that wastewater can be 

safely used in agricultural irrigation. Social acceptance 

of these practices have no doubt been furthered by the 

understanding of the benefits derived from the 

wastewater and the acceptance of its use in this 

Islamic culture through the issuances of fatwas 

allowing wastewater use in agriculture.

Successes and Lessons Learned 

The RIAL projects have demonstrated multiple 

benefits from well-managed reuse projects including 

environmental improvement as wastewater is no 

longer discharged into streams and wadis, increased 

farmer income, and a resultant enhancement of the 

quality of life.

References

About Islam. n.d. Website accessed March 23, 2012

<http://islam.about.com/od/law/g/fatwa.htm>. 

Abu-Awwad, Ahmad M.2006. RIAL Project Presentations. 

April 2006.

Hashemite Kingdom of Jordan Geography and Environment. 

2012. Retrieved on Sept. 6, 2012 from 

<http://www.kinghussein.gov.jo/geo_env4.html>.

INFAD. 2012. Wastewater Treatment. World Fatwa 

Management and Research Institute, Islamic Science 

University of Malaysia. Retrieved on March 23, 2012 from 

<http://infad.usim.edu.my/>.

Maplecroft, 2012. Retrieved on March 23, 2012 from

<http://maplecroft.com/about/news/water_stress_index.html>. 

Solomon, S. 2010. Water - The Epic Struggle for Wealth, 

Power, and Civilization. New York: HarperCollins Publishers.

Figure 1

Irrigated alfalfa field in Wadi Mousa, Jordan (Photo 

credit: Tom Pedersen, CDM Smith)

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2012 Guidelines for Water Reuse

United Nations. 2007. “Coping with Water Scarcity: 

Challenge of the Twenty-first Century World Water Day.” 

March 22, 2007.

USAID. 2008. RIAL Task 1 Completion Report - Reuse for 

Industry, Agriculture and Landscaping Project.

WHO. 2006a. Guidelines for the Safe Use of Wastewater, 

Excreta and Greywater. Volume II - Wastewater Use in 

Agriculture. 

WHO. 2006b. ibid Volume IV - Excreta and Greywater Use 

in Agriculture.

World Bank. 2012. “Wastewater and Excreta Reuse.”

Retrieved on March 23, 2012 from

<http://water.worldbank.org/water/shw-resourceguide/infrastructure/menu-technical-options/reuse>.

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2012 Guidelines for Water Reuse

Water, Wastewater, and Recycled Water Integrated Plan 

for Tijuana, Mexico

Author: Enrique López Calva (CDM Smith)

Mexico-Tijuana

Project Background or Rationale 

The municipalities of Tijuana and Playas de Rosarito, 

with a combined population of more than 1.3 million 

people, represent one of the largest metropolitan 

areas in Mexico, having at the same time one of the 

highest population growth rates in the country. Water 

resources in the region, however, have always been a 

challenge. The accelerated growth, coupled with the 

scarcity of water resources in the area, require 

significant investments to assure water supply for this 

area. Significant challenges exist for the provision of 

water and sanitation services in the area, and deficits 

for the next 20 years are projected to occur if no action 

is taken.

Recognizing the need for immediate planning, the 

Comisión Estatal de Servicios Públicos de Tijuana 

(CESPT) developed a Water, Wastewater and 

Reclaimed Water Integrated Plan (Master Plan) for 

Tijuana and Playas de Rosarito. This master plan was 

developed to address the short-term improvements 

necessary to correct existing system deficiencies and 

long-term upgrades necessary to meet future growth 

through the year 2020.

Capacity and Type of Reuse 

Application 

The Technical Committee selected a water supply 

alternative that resulted in a capital improvement 

program of more than $1 billion U.S. dollars. This 

alternative includes the construction of a desalination 

facility, additional wastewater treatment plants, 

rehabilitation and expansion of the water and the 

wastewater collection network, effluent conveyance 

and disposal lines, and wastewater advanced 

treatment and recycling, including aquifer recharge. In 

addition to the facilities listed in the CIP, the plan 

includes guidelines for aggressive industrial 

pretreatment programs.

Eight wastewater treatment options were identified 

based on the discharge limits established by the 

existing regulations and on the specific discharge 

quality goals established as part of the master plan. 

These technologies include: natural systems 

(lagoons), mechanized lagoon systems, conventional 

activated sludge, trickling filters, extended aeration, a 

combination of trickling filters and activated sludge, 

and sequencing batch reactors.

Based on a comparison of the advantages and 

disadvantages of these options, conventional activated 

sludge was pre-selected for the development of 

alternatives. For reuse options, additional treatment 

was necessary and selected for specific projects 

depending on discharge and/or reuse requirement.

The wastewater treatment plants “La Morita” and 

“Monte de los Olivos” combined effluent was 

recommended for indirect potable reuse, with a 

capacity of 21 mgd (930 L/s). Additionally, 14 mgd 

(600 L/s) were recommended for indirect potable 

reuse from the “Alamar WWTP”. About 20 mgd (900 

L/s) additional were recommended for nonpotable 

reuse in different parts of the city.

Water Quality Standards and 

Treatment Technology 

The water quality goals for the project varied according 

to the reuse options for the different plants. Plants that 

would discharge treated effluent into the Rodriguez 

reservoir, which can supply potable water, required 

quality goals and standards much higher than reuse 

for non-potable uses. 

Plants discharging to the Rodriguez reservoir were 

conceptually designed to have conventional activated 

sludge followed by microfiltration/reverse osmosis 

(MF/RO). This advanced treatment requirement is 

necessary due to the indirect potable use scheme of 

the plants. The plants with effluent destined for nonpotable uses were conceptually designed for 

conventional activated sludge followed with additional 

filtration and hypochlorite disinfection. 

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Project Funding and Management 

Practices 

The master planning project was funded by the North 

American Development Bank, which in turn used funds 

from the U.S. Environmental Protection Agency (EPA). 

After the planning project, implementation of the 

different planning recommendations has proceeded 

with a number of different funding schemes. These 

include financing from foreign banks, funding from the 

national infrastructure bank in Mexico (Banobras), 

funding from the Mexican National Water Commission, 

funding from the North American Development Bank, 

and the EPA. 

Any project financed in total or partially by U.S. funds 

has required environmental documentation in the 

United States under the National Environmental Policy 

Act (NEPA). EPA has developed environmental 

assessments to evaluate transboundary impacts 

(projects in Mexico that could have environmental 

impacts in the U.S. side of the border). 

The projects are managed by the water and 

wastewater utility in Tijuana. The management of 

some projects requires the participation of the U.S. 

and Mexico sections of the International Boundary and 

Water Commission (IBWC).

Institutional/Cultural Considerations 

The project’s decision-making body was formed by 

agencies in Mexico and the United States. A binational 

technical committee was formed to oversee the master 

plan and make technical decisions and 

recommendations. This was necessary due to the 

funding scheme where U.S. funds were utilized for the 

planning project. On the Mexico side of the project, the 

federal government was involved, in addition to the 

local utility, to have a counterpart to EPA. Additionally, 

the project included significant involvement by the 

Border Environment Cooperation Commission and the 

North American Development Bank which are 

agencies with binational character. 

For the implementation of projects, an additional level 

of institutional involvement has been added that 

includes the IBWC. 

The planning project included significant public 

involvement in the United States and on the Mexico 

side of the border. Subsequent phases of 

implementation have continued to include community 

stakeholder participation through the environmental 

document process that has been required on both 

sides of the border. 

A key consideration on the project recommendations 

was the “high-tech” and energy intensive nature of 

some of the projects recommended, namely the 

MF/RO plants. The recommendations were made due 

to the indirect potable reuse nature of some of the 

projects. Alternative plans included no indirect potable 

reuse, eliminating the need for MF/RO. 

Successes and Lessons Learned

The recommendations from the study were accepted 

by the binational technical committee and the great 

majority of community stakeholders. The success of 

the project was due to the high level of bi-national 

cooperation transparency in the decision-making 

process. While conducting a project with a multiagency technical committee is more challenging than 

dealing with one agency only, the benefit is that the 

recommendations from the plan are more likely to be 

accepted and supported. 

The non-potable water reuse options recommended in 

the plan have proceeded successfully with 

environmental documentation, design, and 

construction. While indirect potable reuse options 

requiring MF/RO have not proceeded, a successful 

element of the project and the associated 

environmental documentation is that no secondary 

effluent is being discharged in Rodriguez reservoir, 

which supplies potable water to the city’s residents. 

References

Comision Estatal de Servicios Publicos de Tijuana, 2003. 

Potable Water and Wastewater Master Plan for Tijuana and 

Playas de Rosarito. Prepared by CDM Smith.

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2012 Guidelines for Water Reuse

The Planned and Unplanned Reuse of 

Mexico City's Wastewater

Author: Blanca Jiménez-Cisneros, PhD (Universidad Nacional Autónoma de México) 

Mexico-Mexico City

Project Background or Rationale 

Mexico City is located in what used to be a closed 

basin, at an altitude of 7,350 feet (2,240 meters above 

sea level). The basin was artificially opened in 1857 to 

dispose of waste and stormwater. Mexico City is the 

capital of Mexico and comprises the Federal District 

plus 37 municipalities, and is home to 21.4 million 

people. Water availability in the basin is of the order 

43,600 gallons/inhabitant/yr (165 m3

/inhabitant/ yr) and 

there is a water intensity use of 120 percent. Total 

demand for water is around 1,950 mgd (85,700 L/s). 

The local aquifer is overexploited by 120 percent

(CONAGUA, 2010), leading to the subsidence of the 

soil in some places at a rate of up to 18 in/yr (40 

cm/yr). In addition, water has to be imported from two 

other basins. One is located 62 mi (100 km) away, 

from which water is gravitationally transported, while 

the other is 81 mi (130 km) away, and water must 

pumped up a height of 3,600 ft (1,100 m). Despite 

these efforts, one million people in the city depend on 

the delivery of a limited amount of water in tankers, 

while the rest of the population receives water through 

the network intermittently and sometimes at a very 

reduced flow, rendering it necessary to have water 

storage tanks and pumping systems in the home 

(Jiménez, 2008).

To face the challenge of meeting a constantly 

increasing demand for water, the local water utilities 

which also manage wastewater have implemented 

different projects to reuse wastewater for municipal 

and industrial purposes, some of which have been in 

operation since 1956. In addition, the Federal 

Government has been responsible for a program of 

reuse of water in Mexico City and a second basin for 

agricultural irrigation since 1920 (Jiménez, 2010). 

Capacity and Type of Reuse 

Application 

At the present time, 6 mgd (260 L/s) of water are 

reused to supply different industries. It is problematic 

to sell treated wastewater to industry as it is more 

expensive than tap water and there are no compulsory 

rules to oblige companies to use reclaimed water. It is 

estimated that with a proper legal framework industrial 

reuse could be increased by an additional 23 mgd 

(1,000 L/s). Furthermore, 30 mgd (1,300 L/s) of water 

is supplied to power plants merely for cooling. Nearly 

46 mgd (2,000 L/s) are used for irrigation of green 

areas, recharge of recreational lakes and agriculture; 

27 mgd (1,200 L/s) are used for groundwater recharge 

and 4 mgd (175 L/s) for car washing. New car washing 

service centers are compelled to use reclaimed water. 

In addition, one treatment plant produces 14 mgd (600 

L/s) for ecological purposes. Its effluent is being used 

to recharge a lake that was dried by the Spanish 

during the colonial period and was the source of 

particulate matter heavily polluting Mexico City’s air. 

The last planned public projects began to operate at 

the end of the 1980s. In most of these cases, e.g. the 

power plant, the restored lake, some irrigated areas 

and recreational lakes, pipelines convey treated water 

to the facilities. The other projects receive effluent from 

water tankers. The amount of water reused from public 

plants represents 10 percent of the total supply. 

Additionally, although they are not formally registered, 

several dozen private wastewater treatment plants in 

sports clubs, golf courses and schools treat 

wastewater and reuse it for lawn irrigation or toilet 

flushing. Private reuse is not controlled by the 

government.

The remainder of the wastewater produced in Mexico 

City, amounting 1,370 mgd (60,000 L/s), is reused with 

no treatment for the irrigation of 220,000 acres (90,000 

hectares) in the Tula Valley (Figure 1). This is located 

62 mi (100 km) north of Mexico City. Reuse has been 

performed, although not always officially, for more than 

110 years and as a result the infiltration of the water 

used for irrigation (estimated in more than 570 mgd 

(25,000 L/s) has created new groundwater sources. 

These sources are used to supply the 500,000 people 

living in the Valley with municipal water, using only 

chlorination for treatment. The water has proven to be 

of acceptable quality (Jiménez and Chavez, 2004) 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

thanks to several natural occurring treatment 

mechanisms that happen during its transport, storage,

and infiltration into the soil. In fact, some pollutants 

such as heavy metals and emerging pollutants have 

been shown to remain in agricultural soils for several 

years or even decades (Siebe, 1995; Gibson et al., 

2007; Duran et al., 2009). 

Water Quality Standards and 

Treatment Technology 

With regard to standards, the reuse of wastewater for 

agriculture has been regulated since the 1980s using 

criteria that were modified in 1986 (NOM-001-

SEMARNAT 1986) to manage the quality of the 

treated water to control health risks, i.e., by limiting the 

fecal coliform content to 103 MPN/100 mL and 1 

helminth egg/L for non-restricted irrigation or 5 

helminth eggs/L for restricted irrigation. In addition, a 

higher content of BOD was allowed in order to improve 

the quality of agricultural soils while the amount of 

heavy metals was limited using values set out by the 

EPA, 2004 Guidelines for Water Reuse. There is no 

standard for the reuse of water for industrial purposes. 

For public reuse, water standard NOM-003-

SEMARNAT-1997 is in use, but this only covers 

restrictions for biological pollutants. To regulate the 

infiltration of reused water to groundwater, a relatively 

new standard (NOM-014-CONAGUA-2003) has been 

adopted. This basically only requires compliance with 

the Mexican drinking water standard prior to infiltration. 

The planned reuse of wastewater for industrial and 

municipal purposes is always performed after at least 

secondary treatment coupled with filtration. The 

effluent produced has proven to be adequate for most 

uses, other than for the recharge of recreational lakes, 

notably the Xochimilco Lake, which is currently 

suffering from eutrophication. The power plant 

provides tertiary treatment to a secondary effluent at 

its own cost to avoid the formation of deposits in its 

cooling towers. To recharge the aquifer, treatment up 

to the tertiary level is provided, to remove suspended 

solids and organic matter. No data has been published 

with regard to effluent quality or its impacts on 

groundwater. 

Figure 1

Use of water in Mexico City and the Tula Valley

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2012 Guidelines for Water Reuse

The massive reuse of wastewater for agricultural 

irrigation in the valley is performed with no treatment at 

all, although plans to treat the wastewater and its 

financing have been in place since the mid 1990s.

Project Funding and Management 

Practices 

All investments for public projects have been through 

public funding. All but two wastewater treatment plants 

providing water to industries have been operated by 

private companies since the mid 2000s. Public reuse 

projects are managed by the water utilities of Mexico 

City and the municipalities, while the reuse of water on 

agricultural fields outside the Mexico City basin is 

operated by the federal government. 

Institutional/Cultural Considerations 

In general, society is aware of the reuse of water and 

considers it a positive practice. In fact, in the city there 

are many examples of people, forced by the lack of 

water, reusing wastewater from showers, or the 

washing of clothes for lawn irrigation or the manual 

flushing of toilets with graywater. 

Successes and Lessons Learned

The main lessons learned are that relatively low risk 

practices for reuse have been readily accepted by a 

society that suffers from lack of water. However, 

possible future reuse projects, either in the form of 

new sources of water from the Tula Valley or the direct 

reuse of wastewater in Mexico City for drinking 

purposes, probably will not be accepted as easily for 

many reasons. Perhaps it is time for Mexico City to 

begin to plan to control, its urban growth. 

References

CONAGUA 2010 Water Statistics, SEMARNAT [In Spanish]. 

Jiménez, B. and Chávez, A. 2004. Quality assessment of an 

aquifer recharged with wastewater for its potential use as 

drinking source: “El Mezquital Valley” case. Water Science 

and Technology, 50(2): 269–273.

Jiménez, B. (2008) Water and Wastewater Management in 

Mexico City in Integrated Urban Water Management in Arid 

and Semi-arid Regions around the world. L. Mays Editor. 

Taylor Francis Ltd. 

Durán-Álvarez, J.C., Becerril E., Castro V., Jiménez B., and 

Gibson R. (2009) The analysis of a group of acidic 

pharmaceuticals, carbamazepine, and potential endocrine 

disrupting compounds wastewater irrigated soils by gas 

chromatography-mass spectrometry. Talanta 78(3):1159-66.

Gibson, R., Becerril, E., Silva,V. and Jiménez B. (2007) 

Determination of acidic pharmaceuticals and potential 

endocrine disrupting compounds in wastewaters and spring 

waters by selective elution and analysis by gas 

chromatography – mass spectrometry. Journal of 

Chromatography A, 1169(1-2):31-39.

Siebe, C. Heavy metal availability to plants in soils irrigated 

with wastewater from Mexico City, Water Science and 

Technology, 1995; 32 (12):29-34

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2012 Guidelines for Water Reuse

Maneadero Aquifer, Ensenada, Baja California, Mexico

Authors: Leopoldo Mendoza-Espinosa, PhD, and Walter Daesslé-Heuser, PhD 

(Autonomous University of Baja California)

Mexico-Ensenada

Project Background or Rationale 

The Maneadero aquifer, one of four aquifers supplying 

water to the City of Ensenada, is located in the 

Mexican state of Baja California, where the annual 

average temperature is 63 degrees F (17 degrees C) 

and precipitation is 12 in/yr (299 mm/yr). Groundwater 

is extracted for supplying approximately 100,000 

habitants and to irrigate 16,600 acres (6,714 hectares) 

of a variety of crops, most of which are exported to the 

United States. Overexploitation is calculated at 16,000 

ac-ft/yr (20 Mm3

/y) and has caused severe 

deterioration of groundwater due to saline intrusion 

(Daesslé et al., 2005). Ensenada is growing at a rate 

of 3.7 percent (INEGI, 1997) and so is the demand on 

water supply. Thus, there is the need for short-term 

strategies for the efficient use of water and the 

sustainability of the aquifer.

Ensenada has the advantage of being one of the few 

Mexican cities to treat all of its wastewater. A study 

conducted by Mendoza-Espinosa et al. (2004) 

determined that the El Naranjo wastewater treatment 

plant produces 5,000 gpm (316 L/s) of secondary 

effluent that can be safely used for agriculture 

irrigation yet it is being discharged to the ocean. In 

contrast, in central Mexico wastewater with little or no 

treatment is being used for the irrigation of crops for 

human consumption (Jiménez, 2005).

In order to explore and integrate water management 

alternatives such as water markets, reuse and 

seawater desalination, an optimization model was 

employed (Medellín-Azuara et al., 2007). The study 

indicated that reclaimed water for irrigation and aquifer 

recharge is the most economically promising 

alternative options to meet future water needs. 

Seawater desalination and new aqueducts are not 

economically viable alone, but may also have some 

utility if combined with other options for the region. 

Only recently has there been Mexican legislation for 

planned artificial recharge through the standard NOM014-CONAGUA-2003 (DOF, 2009). Studies by 

Reynoso-Cuevas et al. (2011) demonstrated that 

reclaimed water complies with this norm, and could 

represent an alternative for stopping saline intrusion. 

Capacity and Type of Reuse 

Application 

The city of Ensenada has five wastewater treatment 

plants (WWTP), providing treatment to approximately 

9,500 gpm (600 L/s) of wastewater. The main WWTP 

is called El Naranjo and has a treatment capacity of 

8,000 gpm (500 L/s). It is located approximately 8 mi 

(13 km) north of the Maneadero aquifer. A 25-ft 

(7.6 m) pipe was built in 2008 connecting El Naranjo 

with a holding tank of 530,000 gallons (2,000 m3

) at a 

cost of $4.8 million U.S. dollars. The reclaimed water 

is intended to be used for crop irrigation although it 

could also be used for artificial aquifer recharge. 

Water Quality Standards and 

Treatment Technology 

According to Mexican legislation for wastewater 

disposal, for “land application” of wastewater 

(effectively crops irrigation) practically no treatment is 

necessary, hence its extensive use in Central Mexico. 

However, according to Mexican water reclamation 

standards, the reclaimed water must comply with 

standards similar to those required by California Law 

(Title 22) and suggested in EPA guidelines. The new 

Mexican norm for aquifer recharge requires that for 

direct recharge reclaimed water must basically comply 

with potable water standards; for indirect recharge, 

tests must be undertaken to demonstrate that the soil 

percolation would guarantee the safety and protection 

of the groundwater. Currently the city of San Luis Rio 

Colorado in the state of Sonora is the only Mexican 

city where artificial recharge of a local aquifer has 

been implemented. Ensenada has the potential for 

becoming the second city to achieve this goal. 

Studies by Reynoso-Cuevas et al. (2011) 

demonstrated that Ensenada’s wastewater does not 

appear to have high concentration of trace organic 

chemical contaminants like phenol and 10 of its 

derivatives, 16 polycyclic aromatic hydrocarbons and 7 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

aroclor. The concentration below analytical detection 

limits of these compounds indicates that their 

concentrations are not significant and/or that they are 

transformed to other metabolites through conventional 

wastewater treatment process. Risk minimization 

should certainly be the main element in the 

development of groundwater recharge project; results 

suggest that a combination of controls, such as 

wastewater treatment processes, water quality, 

recharge methods, recharge site and integral 

monitoring, would guarantee the success of the 

recharge operation and preserve a chemically safe 

groundwater. There is the potential for using the 

treated wastewater for direct injection to the aquifer 

although the high levels of total dissolved solids (TDS) 

in the aquifer 1.0-26.0 gl-1 (Daessle et al. 2011) 

remains the biggest challenge for aquifer recharge. Its 

removal via membrane systems will probably be 

required. In view of the high salinity of the aquifer, the 

National Water Commission could grant a special 

permit even if the 1.0 gl-1 TDS limit is exceeded in 

percolation water and only if a minimum distance of 

0.62 mile (1 km) exists between the recharge site and 

the sites of drinking water extraction; further 

hydrogeological studies are being carried out by the 

authors to determine any potentially adverse effects to 

the aquifer.

Project Funding and Management 

Practices 

Funding for Ensenada’s WWTPs and the construction 

of the pipe that connects the Naranjo WWTP with 

Maneadero has been provided by a combination of 

federal and state funds. Comisión Estatal de Servicios 

Públicos de Ensenada (CESPE) has provided funds 

since 1999 for Universidad Autonoma de Baja 

California (UABC) for the continuous monitoring of the 

quality of its WWTPs. All specific research studies 

have been conducted by direct involvement of UABC 

researchers. Government official expect farmers to 

provide their own investment in order to connect to the 

current holding tank and, therefore, to be in a position 

to use reclaimed water for irrigation. On the other 

hand, it is unclear who would provide funds if 

reclaimed water is to be used for the artificial recharge 

of the Maneadero aquifer. 

Although it has been demonstrated that water has an 

economic value (Medellín-Azuara et al., 2009) it 

appears that the availability of water, although of low 

quality due to high TDS as a result of saline intrusion 

is still economically viable even when reverse osmosis 

is needed to obtain irrigation water suitable for crops. 

As TDS in the groundwater continue to increase, it 

may reach a point when this will be no longer viable 

and, thus, reclaimed water could be preferred for 

irrigation.

Institutional/Cultural Considerations 

Farmers are unwilling to irrigate crops with high-quality 

reclaimed water because they believe that the United 

States will block them for exporting their produce. 

Several meetings have been undertaken promoted by 

the academic sector in order to facilitate information 

about reuse schemes in the United States, particularly 

in California. Nevertheless, farmers are reticent as 

they believe that even if they comply with U.S. 

standards for crop irrigation, farmers’ organizations in 

the U.S. may block their produce arguing health risks. 

Moreover, the actual cost for farmers of the reclaimed 

water has not been clearly established. Hence, the 

actual implementation of the reuse scheme has not 

been reached.

Successes and Lessons Learned

As with many water reclamation projects, the scientific 

and technical aspects can be dealt with. In the 

Maneadero case, this has been done slowly but 

surely, often by own initiative of the academic sector. 

Federal and state governments have invested in 

wastewater treatment plants and in reclamation 

facilities. However, the actual implementation of the 

reclamation schemes has been hindered by 

economic/cultural reasons, as farmers are not willing 

to pay for reclaimed water, opting for the continuous 

extraction of underground water. Farmers also worry 

that their product will not be able to be exported to the 

United States if farmers unions in the U.S. find out that

it is being irrigated with reclaimed water, despite its 

compliance with U.S. norms. It appears that this 

deadlock can only be resolved by continuing to reach 

consents between the government and farmers in 

which the academic sector can continue be a facilitator 

and, by all means, undertaking the research to 

guarantee the adequate implementation of water 

reclamation schemes. 

References

Daesslé LW, Sánchez EC, Camacho-Ibar VF, MendozaEspinosa LG, Carriquiry JD, Macías V. & Castro P. (2005) 

Geochemical evolution of groundwater in the Maneadero 

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2012 Guidelines for Water Reuse

coastal aquifer during a dry year in Baja California. 

Hydrogeology J., 13, 584-595.

Daesslé L.W., Perez L., Mendoza-Espinosa L.G., Manjarrez 

E., Licona, A. (2011) An interdisciplinary study of a coastal 

aquifer under the perspective of its overexploitation and 

recharge with treated wastewater. 8th IWA ́s International 

Conference on Water Reclamation & Reuse, Barcelona, 

Spain, 26-29 September.

DOF - Diario Oficial de la Federación (2009). Norma Oficial 

Mexicana NOM-014-CONAGUA-2003, Requisitos para la 

recarga artificial de acuíferos con agua residual tratada. 18-

agosto-2009.

Jiménez, B. (2005). Treatment technologies and standards 

for agricultural wastewater reuse: a case study in Mexico. 

Irrigation and Drainage, 54, S23-S33.

Medellín-Azuara, J., Mendoza-Espinosa, L. G., Lund, J. R., 

and Ramírez-Acosta, R. J. (2007). The application of 

economic-engineering optimization for water management in 

Ensenada, Baja California, Mexico. Water Sci. Technol.

55(1-2), 339-347.

Medellín-Azuara, J., Howitt, R., Waller-Barrera, C. MendozaEspinosa, L. G., Lund, J. R., and Taylor, J. E. (2009). A 

calibrated agricultural demand model for three regions in 

Northern Baja California. Agrociencia, 43(2), 83-96.

Mendoza-Espinosa LG, Orozco-Borbón MV & Silva-Nava P. 

(2004). Quality assessment of reclaimed water for its 

possible use for crop irrigation and aquifer recharge in 

Ensenada, Baja California, Mexico. Water Sci. Technol.

50(2), 285-291.

Reynoso-Cuevas, L., Mendoza-Espinosa, L. G. & Daesslé, 

L. W. (2011). Towards the implementation of planned 

artificial recharge in a coastal aquifer: the Maneadero case. 

8th IWA ́s International Conference on Water Reclamation & 

Reuse, Barcelona, Spain, 26-29 September.

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2012 Guidelines for Water Reuse

Tenorio Project: A Successful Story of 

Sustainable Development

Authors: Alberto Rojas (Comision Estatal del Agua), Lucina Equihua 

(Degremont S.A. de C.V.), Fernando Gonzalez (Degremont, S.A. de C.V.)

Mexico-San Luis Potosi

Project Background or Rationale 

In San Luis Potosi, Mexico, wastewater is considered 

as an asset rather than as a disposable waste. In the 

late 1990s, the State Government of San Luis Potosi 

decided to implement an Integral Plan for Sanitation

and Water Reuse to stop the use of raw wastewater in 

agriculture and foster the substitution of groundwater 

for reclaimed water for all non-potable uses. Currently, 

the state has built seven wastewater treatment plants 

(WWTPs) to treat 70 percent of wastewater and 100 

percent of the treated wastewater is reused. The 

project has not only economical benefits but also a 

positive impact for the local community, in terms of 

public health and environment enhancement.

The reuse program and the industrial users funding/ 

payments gave the system economical viability while 

the augmented water resources become available for 

potable use. The largest WWTP and reuse operation 

(irrigation and industry) of the system is the Tenorio 

Project, a tangible example of how to build and 

operate a sustainable reuse system, water 

governance, balance between treatment and supply 

costs and water rates, performance and reliability.

Capacity and Type of Reuse 

Application 

The Tenorio plant has a total capacity of 24 mgd 

(90,720 m3

/d). The infrastructure consists of primary 

treatment enhanced with chemicals and a natural 

engineered polishing system in a 13.7 mgd wetland for 

agricultural irrigation of fodder crops. 

The treatment required for industrial reuse was 

designed to supply make-up water for cooling towers 

in the “Villa de Reyes” Power Plant, focusing on saving 

groundwater for the surrounding population. The 

industrial reuse relies on a 10.3 mgd treatment 

process using activated sludge with nutrient removal, 

tertiary treatment with lime softening, and sand 

filtration and ion exchange for silica and hardness 

removal. 

The reuse system is comprised of a complex 

distribution system with several pumping stations, an 

irrigation network and a 24 mile (39 km) conveyance 

system with an equalization tank to adjust to the 

industrial hourly demand. 

Water Quality Standards and 

Treatment Technology 

The reclaimed water for irrigation meets standards 

established by Mexican Regulation. These standards 

(Table 1) require guaranteed values in terms of 

biochemical oxygen demand (BOD), total suspended 

solids (TSS), and fecal coliform, which were largely 

exceeded by the treatment chosen.

For the industrial reuse application, the standards 

were established as per the requirements of the Power 

Plant operation. The water quality should guarantee at 

least the same concentration cycles in the cooling 

towers obtained with the groundwater. Therefore, the 

most significant parameters were silica, hardness and 

phosphate content as well as conductivity. However, 

the Power Plant also set limits in BOD, TSS, ammonia, 

fecal coliform, and ferruginous bacteria, in order to 

avoid the increase in cost of conditioning products to 

prevent development of algae and bacteria. To meet 

the latest standards and to prevent biofilm growth in 

the distribution system, a non oxidant biocide control 

was implemented as a complement of the original 

treatment. 

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Project Funding and Management 

Practices 

The WWTP, the 24 mile (39 km) distribution system of 

treated water, an irrigation system for 1236 acre (500 

Ha) and 37 mile (59 km) of sewer pipes required a 

total investment of $67 million USD (May 2004). To 

guarantee reliability and long term operation, the 

project was built with a BOOT (build-own-operatetransfer) scheme and with 18 years of operation. The 

Mexican Federal Government provided 40 percent of 

the capital costs as a grant, while private funding 

provided the remaining 60 percent. Investment and 

operational costs are recovered by the collection of 

three tariffs: one for the private return of the 

investment, and the other two for the fixed and 

variable operational costs.

The Power Plant demand for reclaimed water allowed 

the San Luis Potosi State Water Commission (CEA) to 

undertake the investment risks. The income generated 

from this industrial reuse practically covers the total 

operation cost of the WWTP. Water reuse also 

accounts for an overall reduction of groundwater 

extractions, contributing to the aquifer sustainability. 

Economic benefits to the Power Plant are also 

accomplished by a lower cost and more reliable quality 

of water coming from the WWTP. The fee collected for 

this reclaimed water is 0.23 USD/1000gal (0.85 

USD/m3

).

Institutional/Cultural Considerations 

Industrial and economic development in San Luis 

Potosi has always been related to water availability 

and water conservation efforts. Since 1961, water 

withdrawal from the two main aquifers (San Luis 

Potosi and Jaral-Villa de Reyes) has been strongly 

restricted and farmers used non-treated wastewater 

for irrigation purposes. 

This particular project treats 43 percent of the total 

wastewater, and it is the first one in Mexico which 

makes possible the production of different qualities of 

treated water for multipurpose planned water reuse.

Local farmers considered themselves as the rightful 

owners of all the untreated water available. Farmers 

strongly opposed to any type of water treatment under 

the belief that it would reduce the nutrient content that 

served as fertilizer for their crops. CEA has negotiated 

with them the supply of better quality water and 

convinced them of the sanitary and economical 

benefits gained by using properly treated water. 

Successes and Lessons Learned 

In terms of public outreach, through local educational 

projects and participation in national forums, the 

Tenorio Project has already demonstrated how the 

economic and environmental benefits of reclaimed 

water are helping the city, farmers, and industry. 

Wastewater reuse provides industry with a water 

source which is 33 percent cheaper than groundwater. 

The high-quality water used for irrigation makes it 

possible for farmers to diversify crop production and 

reduce morbidity rate of intestinal and skin diseases.

At the same time, the significant restoration of the 

ecosystem in the Tenorio Tank, that initially received 

wastewater without treatment, was one the major 

successes of the project. The Tank functions as an 

artificial wetland that polishes and improves water 

quality. At present, migratory birds returned to nest in 

the surroundings of the wetland.

After 6 years of operation, this Project accounts for a 

net reduction of groundwater extractions of at least 

Table 1 Main water quality standards for agricultural and industrial reuse 2007-2011

Parameter Raw Wastewater*

Tenorio Tank 

Effluent to Reuse 

in Agriculture**

Criteria for 

Agricultural 

Reuse

Reclaimed Water 

to Power Plant*

Criteria for 

Industrial 

Reuse in 

Power Plant

TSS mg/L 188 (±76) 28.8 (±10.6) 30 3.58 (±3.06) 10

BOD5 mg/L 275 (±99.5) 31 (±7.3) 40 2.87 (±2.05) 20

COD mg/L 518 (±259) 84 (±19) Not required 15.8 (±14.45) 60

PTOTAL mg/L 8.7 (±3.9) 6.5 (±0.2) 15 1.3 (±0.9) 2

TKN mg/L 32.6 (±9.6) 22.3 (±5.1) 25 1.5 (±3.87) 15

Fecal Coli /100 mL 4.8.109(±1.3.102 ) 161 (±402) 1000 18.4 (±16.6) 70

Total hardness mg/L 111.3 (±19.3) Not measured Not required 105.6 (±24.2) 120

Silica mg/L 104 (±20.3) Not measured Not required 64.9 (±9.3) 65

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

40,000 ac-ft (48 million m3). Within the next 2 years, 

the system will be expanded with an additional 

treatment train with an RO unit. This expansion will 

allow the Villa de Reyes Power Plant to replace 

100 percent of its water demand with reclaimed water 

and the San Luis Potosí water availability will be 

increased by 10 mgd when the power station transfers 

all their groundwater rights to the city, for potable use.

References

Medellín P. (2003) Tanque Tenorio, 10 años después, Pulso 

de San Luis Potosí, 4a Edition

Equihua L. O. (2006) Reuso de agua en la agricultura y en la 

industria en México: Caso del Proyecto San Luis Potosi, 

Foro del Agua, 2006

Diario Oficial de la Federación (2009) Actualización de la 

disponibilidad media anual de agua subterránea acuífero 

(2411) San Luis Potosí, Estado de San Luis Potosí

Díaz de León U. (2008) Saneamiento integral y reutilización 

del agua en la ciudad de San Luis Potosi México, Expo 

Zaragoza, 2008

Rojas A. (2011) Experiencia de reuso del agua tratada en la 

Zona Metropolitana de San Luis Potosí., Jornadas técnicas 

sobre la recarga artificial de acuíferos y reuso del Agua, 

Instituo de Ingeniería UNAM.

Figure 2

Tenorio Tank with different species of migratory birds 

(Photo credit: Degremont)

Figure 1

Aerial view of Tenorio Tank, WWTP, and land irrigated 

with reclaimed water (Photo credit: Degremont)

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2012 Guidelines for Water Reuse

Faisalabad, Pakistan: 

Balancing Risks and Benefits

Author: Jeroen H. J. Ensink, PhD (London School of Hygiene and Tropical Medicine)

Pakistan-Faisalabad

Project Background or Rationale 

The International Water Management Institute (IWMI) 

started a program in 2000 that aimed to quantify both 

the risks and benefits of wastewater use in Pakistan. 

For this purpose the city of Faisalabad was selected 

for a 5-year study program. This city was selected for 

a number of reasons: 1) over 6,200 ac (2,500 ha) of 

land is irrigated with domestic wastewater, and 2) even 

though a waste stabilization pond (WSP) was present, 

farmers preferred to use untreated wastewater. At the 

start of the study different cost (health risks) and 

benefits were identified for which separate studies 

were designed.

Capacity and Type of Reuse 

Application 

The WSP in Faisalabad is located in a predominantly 

agricultural area and has been in operation since 

January 1998 and was constructed with the aid of an 

international grant. It covers an area of almost 250 ac 

(100 ha) and consists of six parallel anaerobic ponds 

and two series each comprising one facultative pond 

and two maturation ponds. The plant was designed for 

a wastewater flow of 24 mgd (90,000 m3

/d) with an 

average influent biochemical oxygen demand (BOD) of 

380 mg/L. BOD removal at the design stage, based on 

a total hydraulic retention time (HRT) of 16.5 days and 

calculated following standard procedures, was 

determined to be 80 mg/L. This would result in an 

effluent with BOD in compliance with the Pakistan 

Environmental Protection Agency’s standard for the 

disposal of municipal and industrial wastewater 

effluents which is set at ≤80 mg/L.

Wastewater is pumped on a 24-hour basis from the 

main sewerage network into a primary drain bringing 

wastewater to the WSP. Local farmers, following 

extensive legal cases and now with permission from 

the local Water and Sanitation Authority (WASA), have 

installed five permanent outlets in the primary drain to 

convey untreated wastewater to their existing irrigation 

networks. Farmers were reluctant to use treated 

effluent as they claimed it was unsuitable for use in 

agriculture as it was much lower in nutrients and much 

higher in salinity (as a result of massive evaporation 

from the WSP) than untreated wastewater.

Approximately 290 farming households paid annual 

fees totaling USD $7,500 (440,000 Pakistan rupees) to 

the WASA to use wastewater. The main crops 

cultivated with wastewater were fodder, wheat, and 

vegetables. The vegetables included: spinach, 

cauliflower, eggplant, chilies, and tomatoes. 

Farmer Perception and WSP 

Performance 

A 1-year study showed a strong increase in salinity 

from untreated wastewater to final effluent with a clear 

decline in nitrogen concentration, thereby confirming 

farmer perceptions. The performance of the WSP was 

poor and did not comply with WHO and FAO 

guidelines for irrigation water. The poor performance 

of the WSP could be attributed to a combination of 

factors: poor design, the extreme climatic conditions, 

which causes evaporation exceeding 0.4 in/day (10

mm/day) during several months of the year. Also the 

large quantities of untreated wastewater that were 

diverted for agricultural irrigation by farmers meant that 

the hydraulic retention time was more than doubled 

due the reduced amount of raw wastewater inflow.

Water Quality 

The water used for irrigation was untreated 

wastewater with high concentrations of E. coli

(geometric mean: 1.8x107 CFU/100 mL) and helminth 

eggs (over 950 eggs/L) and exceed international 

standards, though no official wastewater use 

standards were adopted by the state of Pakistan. 

Risks to Farmers 

The health risks of wastewater use in agriculture were 

investigated through a cross-sectional study. The 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

study showed an increased risk of intestinal nematode 

infection, and in particular hookworm infection, in 

wastewater farmers (OR = 31.4, 95% CI 4.1-243) and 

their children (OR = 5.7, 95% CI 2.1-16) when 

compared to farming households using regular (nonwastewater) irrigation water, though the prevalence of 

infections was low (Ensink, 2005). In addition an 

increased risk of Giardia intestinalis infections was 

found within the wastewater farming communities, 

though the large majority of infections were found to 

be asymptomatic (Ensink, 2006). The study further 

found elevated levels of heavy metals in soil irrigated 

by untreated wastewater but levels remained within 

permissible guidelines set by international agencies. 

No elevated levels of heavy metals were found in 

edible parts of agricultural produce (Ensink, 2008).

Farmer Benefits 

During the study farmers using different types of 

irrigation water (untreated wastewater, and ‘normal’ 

[non-wastewater] irrigation water) were followed. Crop 

choice, crop yields, water use and fertilizer 

applications were monitored for all selected farmers for 

the duration of a year. Farmers using untreated 

sewage were found to grow crops of higher value 

(predominantly vegetables), have a higher cropping 

intensity per hectare and finally and most important 

only applied fertilizer through wastewater, with minimal 

amounts of chemical fertilizer. On average a farmer 

using untreated wastewater had an income that was 

US$ 600/ha higher than a farmer that used normal 

irrigation water (Ensink, 2007)

Risks to Consumers 

The risk to consumers were quantified in a year-long 

study in which produce grown on untreated 

wastewater was analyzed for the presence of E. coli

and helminth eggs. At time of harvest one batch of 

sample was collected from the fields and the same 

batch of vegetables was followed up and collected at 

the local market the next day. The study found that 

slow growing vegetables had the highest levels of 

contamination, though in general contamination levels 

were low with on average 1.9 E. coli/gram of produce. 

Higher concentrations of E. coli (14.3 E. coli g-1) were 

recovered from the vegetables collected from the 

market, with the results of the survey suggesting that

unhygienic post harvest handling was the major 

source of produce contamination (Muhktar, 2008). 

The construction of WSP has been suggested to pose 

a risk to urban populations as the large reservoirs 

could provide breeding sites to disease vectors. The 

WSP in Faisalabad was found to generate large 

amounts of mosquitoes; most notably the vectors of 

malaria, Japanese encephalitis, dengue, and 

lymphatic filariasis (Ensink, 2007). However mosquito 

breeding was predominantly associated with emergent 

grasses and the absence of grids within the WSP. 

Removal of grasses and the reinstallation of the grids 

reduced mosquito breeding to almost zero (Ensink, 

2007)

Benefits to Consumers 

A comparative analysis of food prices found that 

locally grown wastewater irrigated cauliflower was 

almost 50 percent cheaper than produce irrigated with 

non-wastewater water brought into the city (Ensink, 

2007).

Risks and Benefits to Downstream 

Water Users

A nationwide survey in Pakistan found that only 

2 percent of all cities with a population of over 10,000 

inhabitants had wastewater treatment facilities, and in 

those that did have wastewater treatment facilities at 

maximum 50 percent of all wastewater received some 

form of treatment. In addition in 80 percent of all cities 

in Pakistan untreated wastewater seemed to occur, 

and occurred in all cities that had a sewerage systems 

(Ensink, 2004).

As a result of natural occurring salinity approximately 

50 million people in Pakistan rely on irrigation canals 

for their domestic water supply, including drinking (Van 

der Hoek, 2001). In the absence of wastewater 

treatment, wastewater is disposed of untreated into 

irrigation canals and rivers, thereby exposing 

downstream water users to unknown health risks.

Lessons Learned

The Faisalabad case study shows that wastewater use 

for crop production is a practice with many benefits. It 

sustains livelihoods of poor peri-urban farming 

families, contributes to urban food security, helps in 

solving the urban sanitation problem by preventing 

pollution of surface water, and makes optimal use of 

the resources (water and nutrients). The health risks 

associated with wastewater use in agriculture to farmers and consumers of produce can be reduced by 

proper irrigation water management and implementaE-86
Appendix E | International Case Studies

2012 Guidelines for Water Reuse

tion of existing public health measures, even when 

wastewater treatment is not feasible. It is therefore 

paramount that when wastewater treatment facilities 

are planned, farmers’ views need to be taken in 

consideration. 

References

Ensink, J.H.J., et al., High risk of hookworm infection among

wastewater farmers in Pakistan. Trans R Soc Trop Med Hyg,

2005. 99(11): p. 809-18.

Ensink, J.H., W. van der Hoek, and F.P. Amerasinghe, 

Giardia duodenalis infection and wastewater irrigation in

Pakistan. Trans R Soc Trop Med Hyg, 2006. 100(6): p. 538

42.

Ensink, J.H.J., R.W. Simmons, and W. van der Hoek,

Livelihoods from wastewater: water reuse in Faisalabad,

Pakistan, in International survey on water reuse, B. Jimenez 

and T. Asano, Editors. 2008, International Water Association 

Publishing: London, UK.

Ensink, J.H., T. Mahmood, and A. Dalsgaard, Wastewater

irrigated vegetables: market handling versus irrigation water

quality. Trop Med Int Health, 2007. 12 Suppl 2: p. 2-7.

Ensink, J.H., et al., Simple intervention to reduce mosquito

breeding in waste stabilisation ponds. Trans R Soc Trop

Med Hyg, 2007. 101(11): p. 1143-6.

Ensink, J.H.J., et al., A nation-wide assessment of 

wastewater in Pakistan: an obscure activity or a vitally 

important one? Water Policy, 2004. 6: p. 197-206.

Mukhtar, M., et al., Importance of waste stabilization ponds

and wastewater irrigation in the generation of vector

mosquitoes in Pakistan. J Med Entomol, 2006. 43(5): p. 996

1003.

Van der Hoek, W., et al., Irrigation water as a source of

drinking water: is safe use possible? Trop Med Int Health,

2001. 6(1): p. 46-54.

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2012 Guidelines for Water Reuse

Friends of the Earth Middle East's Community-led Water 

Reuse Projects in Auja

Author: Elizabeth Ya'ari (Friends of the Earth Middle East)

Palestinian Territories-Auja

Project Background or Rationale 

The Village of Auja is located adjacent to the Jordan 

River just north of the City of Jericho. It is a small 

community of 4,500 residents, well known in 

Palestinian society due to the nearby Auja Spring, 

where an estimated 9 million cubic meters (m3

) 

(7,300 ac-ft) of water annually flows out of the desert 

rocks. The oasis created by the Auja Spring attracts 

thousands of visitors each year. 

In close partnership with the community and the Auja

Municipality, Friends of the Earth Middle East 

(FoEME) established its Jordan Valley Environmental 

Education Center with guest house facilities in 2010 

(Figure 1). The center has quickly become a central 

institution of Auja and a focal point for environmental 

awareness for visitors and students about the geology, 

fauna, flora, water resources, and cultural heritage of 

Wadi Auja and the Jordan Valley as a whole.

Capacity and Type of Reuse 

Application 

The center was designed at the outset to include 

educational demonstration model water reuse 

installations including a graywater treatment system. 

These systems reduce water consumption, save costs 

and scarce resources, provide a source of irrigation 

water for the center's trees, and serve as educational 

models in action for visitors to the center. 

The center's graywater reuse system treats graywater 

generated by the guest house and center's kitchen 

and bathroom sinks and showers for reuse in irrigating 

trees in the center's grounds. The system includes two 

parallel filtration systems, with 10 containers each, 

connected in a series (Figure 2). The system acts as a 

series of constructed wetlands, whereby in the first 8 

containers gravel and phragmites (similar to bamboo) 

filters the graywater, followed by a gravel and sand 

composite in the 9th container, and finally an all sandfilled container for the last stage. The treated water is 

held in a 35.3-ft3 (1-m3

) storage container, where an 

automatic pump pushes the treated water through the 

drip-irrigation system at the center. At full capacity the 

system can treat an estimated 8,000 gallons (30 m3

) of 

water a day. 

Figure 1

FoEME's Auja Environmental Education Center

Figure 2

Graywater reuse system

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Project Funding and Management 

Practices 

The water reuse system cost approximately $5,000 US 

and was funded by the U.S. Agency for International 

Development (USAID) and other donors as part of 

their support for the Auja Environmental Education 

Center. It has been operational for a year and is 

quickly becoming a model installation for water reuse 

projects for private homes in Auja and throughout the 

West Bank. 

To ensure the project's replication and sustainability, 

FoEME produced a graywater installation manual 

(Figure 3) and led a training course at the center in 

which dozens of area residents were training in the 

installation and maintenance of graywater systems 

(Figure 4). Institutional/Cultural Considerations 

Trainings, seminars, and workshops at the Auja 

Center have involved a total of 384 people with an 

additional 3,318 youth and adults receiving an 

environmental education experience as part of their 

visit to the Auja EcoCenter in the last 6 months. 

Building on the success of this wastewater solution for 

the Palestinian community of Auja, Osprey Foundation 

agreed to support the installation of graywater systems 

at homes throughout the community of Auja. 

Successes and Lessons Learned

Building on the success of this wastewater solution for 

the Palestinian community of Auja, Osprey Foundation 

agreed to support the installation of graywater systems 

at homes throughout the community of Auja. 

Figure 3

FoEME's graywater system installation manual in 

Arabic

Figure 4

Graywater workshop for youth at Auja Center

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2012 Guidelines for Water Reuse

Assessing Water Reuse for Irrigation in Huasta, Peru

Authors: Daphne Rajenthiram (CDM Smith); Elliott Gall and Fernando Salas (University 

of Texas); Laura Read (Tufts University)

Peru-Huasta

Project Background

The rural community of Huasta is located in the 

southern portion of the district of Huasta, within the 

Bolognesi province of the Ancash region Peru 

(Figure 1). A key organization within Huasta is the 

Campesina Community. The Campesina Community 

may be thought of as a “Homeowners Association,” 

where members collectively decide how community 

resources (land, agriculture, livestock etc.) will be 

utilized, managed, and distributed to participating 

members. 

As a proactive response to the persistent dry 

summers, five communities (including Huasta) have 

formed the Tres Cuencas Commonwealth for the sole 

purpose of collectively mitigating water issues within 

these communities. This collaborative effort initiated by 

the communities themselves has presented a unique 

opportunity for Engineers without Borders Greater 

Austin Chapter (EWB-AUS) to get involved. The five 

communities in the commonwealth are populated with 

indigenous Andeans, who are traditional small-scale 

farmers and ranchers who live closely in shared 

residences with their neighbors. Residents live in 

courtyard-type dwellings where the kitchen and 

common areas are shared. Houses in Huasta are

typically set up with a central courtyard that connects 

the sleeping rooms, kitchen, and washing area. 

Huasta has a central plumbing system with flush toilets 

implemented in combination with the community 

wastewater treatment plant built approximately 6 years 

ago.

The community of Huasta has a vested interest in 

improving water availability in the area, as it is a driver 

for economic success. The community owns a number 

of livestock, primarily cows whose milk is sold 

regionally to produce cheese. Since cows require 

grass to graze on throughout the year, and the 

summer months provide little to no rainfall, limited 

water resources are further stressed during the dry 

season. The President of the community and a 

representative from the agricultural water committee 

identified water for irrigation in the dry season as their 

major concern for continuing to expand their dairy 

production. Members of the community own parcels of 

land that are permitted for use for grazing animals.

Type of Reuse Application 

The municipality of Huasta and the Campesina 

Community conveyed their interest in a water 

reclamation project to EWB-AUS during the initial 

program assessment in August 2011. They were 

particularly interested in the idea as it would increase 

the area of productive land in the community and draw 

Figure 1

Location of Huasta, Peru

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from a currently unused resource. The project may 

also improve on current flood irrigation techniques and 

promote water conservation gains through an 

enclosed pipe to transport irrigation water for flood, 

spray, and/or drip irrigation systems. 

The purpose of the follow-up assessment trip in 

January 2012 was to determine the feasibility of 

utilizing reclaimed water from the community 

wastewater treatment plant to irrigate a 0.405-ac 

(1-ha) community-owned pasture. This land is 

currently not served by the community’s irrigation 

network as it is at a higher elevation than the canals 

that provide water during the dry season (from JuneAugust). The current treatment train at the wastewater 

treatment plant (WWTP) (Figure 2) consists of a 

headworks grate at the influent inlet, three 

sedimentation basins in parallel, two clean out tanks in 

parallel, followed by a sand filtration (currently 

bypassed) structure. EWB-AUS is currently analyzing 

viable and feasible options to improve water quality of 

the effluent including getting the sand/gravel filter bed 

operational, increasing the residence time at the 

sedimentation tanks, etc. From the plant inspection 

made in January of 2012, it was observed that if the 

treatment structures are operated as intended, the 

water quality of the effluent will be satisfactory for 

irrigating a grass field which will be used to graze the 

community livestock.

WQ Standards 

To our knowledge, two levels of reuse regulations exist 

for Peru, the first stipulates minimum requirements for 

WWTP effluent. The other Peruvian rule defines reuse 

requirements for watering animals. But no national 

regulation exists for irrigation reuse.

Also, the World Health Organization (WHO) 

recommends treatment processes for restricted and 

unrestricted irrigation. The team was guided by the 

WHO Guidelines for the Use of Wastewater in 

Agriculture to ensure that the existing WWTP meets or 

exceeds the requirements for non-contact irrigation 

(WHO, 1989). 

Project Funding and Management 

Practices 

Funding for the EWB-Peru project for travel, materials, 

installation, etc. has and will be raised by the local 

EWB-AUS. Also, if the reuse project proceeds as 

planned, a wastewater committee will be formed 

consisting of the local Campesino Community 

members. This committee will be expected to collect 

community tax, as applicable, and will be the decision 

making authority over the long-term operation and 

maintenance of the reuse system. The committee’s 

role is crucial for this project’s sustainability. The 

project team travelling this summer is planning to 

educate the proposed committee on importance of 

maintaining the WWTP and the impact of 

operation/maintenance of the plant on the effluent 

quality. As a part of this workshop, the members of the 

wastewater committee will be trained in monitoring the 

effluent quality for bacterial population and 

biochemical oxygen demand (BOD). 

The project is currently managed by EWB-AUS 

members working in conjunction with The Mountain 

Institute (TMI), a local non-profit organization in Peru 

for coordination and input from the community in the 

decision making process of the project.

Stakeholder Involvement 

Existing effluent water quality data was collected by 

the team and presented to the community and the 

local municipality (Figure 3). Since the bacterial 

population in the effluent is exponentially higher than 

recommended levels, the travel team accepted the 

request from the community to create a maintenance 

and monitoring plan for the WWTP to improve 

treatment and effluent quality. Currently, EWB-AUS is 

working on preparing a maintenance plan and 

monitoring kit designed to train the local community 

members to properly operate and maintain the WWTP.

Figure 2

Existing WWTP

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Successes and Lessons Learned

The positive outcome from the assessment trip was 

identifying the need to educate the community on the 

importance of the operation and maintenance of the 

WWTP. The fate of the reuse project depends on the 

results from the continued plant monitoring against

WHO standards (mainly bacteria and BOD) that is to 

be performed by the Huasta community. The feasibility 

of the reuse project depends upon the data collected 

from monitoring. EWB-AUS will continue to work with 

the community of Huasta throughout this project. 

References

WHO (1989) Health Guidelines for the Use of Wastewater in 

Agriculture and Aquaculture. Report of a WHO Scientific 

Group, Technical Report Series No. 778, WHO, Geneva.

MINAM. 2008. Arpueba los Estandares Nacioinales de 

Calidad Ambiental para Agua. Decreto Supremo No 002-

2008-MINAM.

Figure 3

Community meeting

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2012 Guidelines for Water Reuse

Wastewater Treatment and Reuse for Public Markets: 

A Case Study in Sustainable, Appropriate Technology

in the Philippines

Authors: Mary Joy Jochico (USAID) and Ariel Lapus (USAID PWRF Project)

Philippines-Market

Project Background or Rationale 

Public markets in the Philippines and around Asia 

pose significant challenges for wastewater treatment 

due to the relatively high strength of the discharges 

and variability of flows. The Muntinlupa Public Market, 

located in Muntinlupa City in the southern part of Metro 

Manila, is one of the largest public markets in the 

metropolitan area with 1,448 stalls and 24 hours a day 

operation (Figure 1). Wastewater generated at 

Philippine public markets tends to be very high 

strength and land available for treatment is generally 

quite small, necessitating a unique solution. 

With support for planning and design provided by the 

United States Agency for International Development 

(USAID) through the Local Initiatives for Affordable 

Wastewater Treatment (LINAW) project, the city 

constructed a treatment facility that began operating in 

February 2006. In addition to treating wastewater from 

the public market, the system incorporates a water 

recycling system that allows reuse of the treated 

effluent for flushing toilets, watering plants and street 

cleaning. In addition to Muntinlupa, the LINAW project 

is assisting six cities in the Philippines to build 

wastewater treatment facilities for public markets using 

appropriate, low-maintenance technologies

Capacity and Type of Reuse 

Application 

The wastewater generated from the public market 

contains high levels of organic matter (more than 

600 mg/L biochemical oxygen demand [BOD]) and 

solids classifying it as high-strength wastewater. The 

wastewater is from the market comfort rooms (sinks 

and toilets) and from cleaning/rinsing of fish, meat, 

poultry, vegetables, etc. The treatment system that 

was designed for the Muntinlupa Public Market 

Wastewater Treatment Facility is an innovative 

combination of anaerobic and aerobic treatment 

coupled with filtration to meet local discharge 

standards. Since the available land area for the 

treatment system was very small, the solution was to 

place the 5,646 ft2 (160 m3

) treatment system 

underneath a parking lot. The water recycling system 

treats 0.055 mgd (210 m3/day) of wastewater per day, 

of which 50 percent is discharged to Laguna de Bay 

Lake, and 50 percent is reused for flushing toilets, 

watering plants, and street cleaning. This technology is 

being applied elsewhere in the Philippines and is 

suitable for other locations in the region. 

Water Quality Standards and 

Treatment Technology 

The technology is low-cost and low-maintenance, 

costing a third less to construct and nearly half of the 

monthly operation and maintenance costs of a 

conventional (activated sludge) plant. The system is 

an anaerobic baffled reactor coupled with a 

sequencing batch reactor, followed by media filtration 

Figure 1

Location of water reuse – the Muntinlupa 

City public market

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and disinfection. Wastewater enters the tank from the 

bottom of the first zone of the anaerobic baffled reactor 

(ABR) where a granular sludge blanket is formed. As 

the wastewater flows upwards through the sludge 

blanket, organic particles are trapped and degraded by 

the anaerobic bacteria present in the sludge blanket. 

With each pass through subsequent chambers, the 

wastewater is further treated. When it arrives in the 

sequencing batch reactor (SBR), atmospheric oxygen 

is mixed with the flow to produce a highly treated 

oxygenated effluent. The final step is secondary 

clarification followed by disinfection using chlorine 

injection to meet local discharge standards. Figure 2

shows the final stage of treatment - filtration through 

coco-peat, a waste product from coconut husk 

processing. Another project was demonstrated in the 

public market in which a container of ‘coco-peat,’ is 

used as a wastewater treatment filter. This is now 

being replicated for wastewater treatment in two 

schools in Muntinlupa City. 

The Philippine Revised Effluent Regulations of 1990 

(DAO-35) sets national requirements for treated

wastewater discharge into various receiving water 

body classes. New or proposed industries and 

wastewater treatment plants that will discharge to 

Class C (inland waters) must meet the following 

effluent standards (in addition to other limits for toxic 

compounds), as shown in Table 1. 

Table 1 Philippine DAO-35 Class C wastewater 

discharge requirements

Parameter Unit

Class C 

Requirements

Color Pt-Co units < 150

Temperature (max rise 

in degree Celsius in 

RBW)

°C rise <3

pH (range) 6.5 – 9.0

COD mg/L < 100

Settleable Solids 

(1-hour) mg/L < 0.5

5-Day 20°C BOD mg/L < 50

Total Suspended 

Solids mg/L < 70

Total Dissolved Solids mg/L —

Surfactants (MBAS) mg/L < 5.0

Oil/Grease (Petroleum 

Ether Extract mg/L < 5.0

Phenolic Substances 

as Phenols mg/L < 0.1

Total Coliforms MPN/100mL < 10,000

All required parameters are being met by the system. 

Project Funding and Management 

Practices 

The system was installed over a 7-month period and 

cost 6.8 million Philippine pesos (P) ($130,000). The 

ongoing operating costs are P 27,000 per month, but 

an overall savings of P 15,000 per month is realized 

because of lower overall water consumption at the 

market. 

Muntinlupa City formed a Lake Management Office 

(LMO) whose function is to manage and protect a 

portion of the nearby lake. Covering a total area of 

14,589 ac (5,904 ha), the LMO took over operations of 

monitoring and controlling pollution of the lake area, 

implement environmental laws, regulating structures in 

the lake community and serving the fishermen who 

relied on the lake for their livelihood; The Local 

Government passed Local Ordinance No. 02-070 

which stipulates proper disposal of wastewater and 

gives strict sanctions/fines for noncompliance. 

Two employees regularly monitor the operation of the 

facility and report any problems that will occur during 

the operation to the Muntinlupa Public Market 

Cooperative. 

Figure 2

The public market was also the demonstration site of 

the use of "coco-peat" for wastewater filtration

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Cost recovery is through a daily charge of $0.10 to 

individual stall owners. Mr. John Emmanuel Pabilonia, 

LINAW Team Leader for Muntinlupa City, confirmed 

that since its operation in 2006 Muntinlupa City has 

fully recovered the cost of the construction and the 

fees sustain the operation and maintenance of the 

facility.

Institutional/Cultural Considerations 

As part of this project, a demonstration was done to 

help inform the public and policy makers about the 

unique solution and application of water reuse. The 

public market also hosted a demonstration project to 

show the public how a container full of coco-peat is 

used as a filter for final treatment in some wastewater 

treatment schemes being installed in two schools in 

Muntinlupa City (Figure 2). As part of the start-up of 

the system, former Muntinlupa City Mayor Jaime 

Fresnedi was asked to inaugurate the public market 

wastewater treatment plant by turning on a faucet of 

treated water for reuse (Figures 3 and 4).

The LGU’s key partners include USAID’s Local 

Initiative for Affordable Wastewater Project and the 

public market cooperative as direct stakeholder.

Successes and Lessons Learned

This project was able to demonstrate that proper 

incentives and identifying economic drivers can 

motivate local governments to prioritize environmental 

protection. In the case of Muntinlupa City, capital 

investment for environmental protection was not 

necessarily a high priority of the local government but 

with increased awareness on the environmental and 

health impacts of pollution along with the technical 

assistance that showed that capital investments can 

be recovered through user charges, the local 

government willingly paid for the construction of the 

wastewater treatment plant. 

References

Revised Effluent Regulations of 1990. 1990. Department of 

Environment and Natural Resources (DENR) Administrative 

Order (DAO)-35, Government of the Republic of the 

Philippines. Retrieved April 4, 2012, from

<http://www.emb.gov.ph/laws/water%20quality%20manage

ment/dao90-35.html>.

Figure 3

LINAW Team Leader for Muntinlupa City John 

Emmanuel Pabilonia and former Muntinlupa City 

Mayor Jaime Fresnedi inspect the construction of 

the public market treatment facility.

Figure 4

Former Muntinlupa City Mayor Jaime Fresnedi, with 

former Environment Secretary Elisea Gozun (behind 

the Mayor) inaugurates the public market 

wastewater treatment plant by turning on a faucet of 

treated water for reuse.

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2012 Guidelines for Water Reuse

Use of Wastewater in Urban Agriculture in Greater Dakar, 

Senegal: “Adapting the 2006 WHO Guidelines”

Author: Seydou Niang, PhD (Cheikh Anta Diop University of Dakar)

Senegal-Dakar

Background 

Although the city of Dakar, Senegal, is located in a 

developed zone of favorable micro-climate and 

hydrology, its ecosystem is very sensitive (permeable 

sandy soil, shallow groundwater level). Furthermore, in 

the coastal aquifer (Thiaroye) northeast of Dakar City 

(Figure 1), severe problems concerning groundwater 

quality occur: 1) salinization due to seawater intrusion 

or dissolution of salts in the unsaturated zone, and 2) 

degradation from anthropogenic contamination (septic 

tanks leaking, latrines, urban agriculture). An important 

increase in nitrate concentration and salt load are the 

most pronounced impacts (Pfeifer and Niang, 2009).

The scarcity of good quality freshwater resources in 

and around the city has led local populations to make 

greater use of wastewater in urban agriculture. Reuse 

of wastewater helps to sustain the city’s thriving 

agriculture sector. Indeed, urban agriculture in and 

around Dakar is critical to the city’s economy and 

livelihoods, ensuring more than 70 percent of the city’s 

fresh vegetable supply and employing thousands of 

people (Ndiaye, 2009).This greater use of wastewater 

nonetheless imposes costs. Irrigation with wastewater, 

enhances salt accumulation in soils that releases to 

the shallow groundwater (Kass et al., 2005; Leal et al., 

2009; Vengosh, 2003) and leads to microbiological 

contamination of crops, soils, groundwater and 

increases health risks for farmers, handlers and 

consumers (Ndiaye, 2009). 

Project Rationale

This project sought to understand 1) how livelihoods 

and health of the local population could be improved 

through analysis of microorganisms and parasites from 

their source (wastewater, manure) to the markets 

where the produced vegetables are sold, and 2) how 

current urban agricultural practices (such as 

amendments, irrigation, use of pesticide) influence the 

environment, in particular the soil and groundwater 

quality.

The main result of the study was to provide policy 

makers with new guidelines based on the 

recommendations of WHO in 2006. The goals of these 

guidelines are, in terms of microbiological reduction, 

6-7 log10 pathogen reduction through sets of 

measures:

 Wastewater treatment with 3-4 log10 pathogen 

reduction

 Die off (delay between last irrigation and 

harvesting) with 3-4 log10 pathogen reduction

 Washing of produce with 1 log10 pathogen 

reduction

Capacity and Type of Reuse 

Application 

The main wastewater reuse site in urban agriculture in 

Dakar is Pikine. Of Pikine’s total cultivated area of 

approximately 120 acres (50 ha), about 40 acres (16 

ha) makes use of raw wastewater for irrigation. 

Usually, farmers divert wastewater from the sewage 

using pipes to load narrow wells located in their plot 

(Figure 2). From that well, they use water cans to 

irrigate crops such as lettuce, which grow rapidly—a 

crop characteristic that is important to farmers without 

Figure 1

Hydrogeology and field situation (Pfeifer and Niang, 

2009)

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secure land tenure. This practice of raw wastewater 

reuse for irrigation is being reduced due to 

upgrades/expansion of the city sewage system

performance. 

Water Quality Standards and 

Treatment Technology 

In Senegal, the law which regulates wastewater use in 

agriculture is the Hygiene Code. It stipulates in its 

article 41 (Law N° 8371 of July 5, 1983) that dumping 

of rubbish or discharge of wastewater is forbidden on 

all lands where fruits and vegetables consumed raw 

are grown, where the edible parts are grown in contact 

with the rubbish or wastewater. Organic fertilizers, 

manure, and compost cannot be utilized within one 

month before harvesting. Fruits and vegetables should 

be soil free. If washing of fruits or vegetables is 

necessary, only potable water can be used, which then 

must be properly drained for disposal. (Gaye and 

Niang, 2010). 

This law, inspired by the 1992 WHO guidelines, needs 

to be updated based on the new WHO vision that now 

considers epidemiological risks instead of focusing on 

the calculation of microbiological concentration levels 

in irrigation water and vegetables. Currently, WHO 

recommends a set of measures to reduce risks related 

to the use of wastewater in urban agriculture. 

Using the 2006 WHO guidelines, the study tested the 

viability of using three types of lagoon systems. The 

first treatment line is a combination of four ponds of 

530 gallons (2 m3

) in series: two stabilization ponds, 

one pond planted with Cattail, and an immerged gravel 

filter pond. A surface and subsurface inverse vertical 

flow system circulates the water through the system. 

The second treatment line, with the same number and 

size of ponds, consists of one stabilization pond 

followed by three reed-planted ponds with free water 

surface and surface water flow. The third treatment 

line has one stabilization pond and three planted filters 

with Vetivera sp. For E. coli, all treatment lines 

achieved 4 log units reduction, and for Ascaris eggs 

100 percent removal was achieved everywhere (Niang 

et al. 2009).

Institutional/Cultural Considerations 

The local land tenure situation constitutes the biggest 

obstacle to investments of farming improvements and 

expansion. While there is one Council Order that 

provides some protection for local access to land, 

farmers often lack clear legal right to specific plots. As 

a result, plots are often taken and used for housing; 

therefore, farmers are reluctant to make medium to 

long-term investments.

A clear policy statement by public health officials 

concerning the use of wastewater under certain 

conditions will help farmers secure a more formalized 

status rather than potentially being in violation of the 

law. 

As farmers are placed under the stress of losing their 

plot because of housing or their harvest because of 

hygiene issues, they prefer fast growing crops like 

lettuce. 

Successes and Lessons Learned

In applying the 2006 WHO guidelines to Pikine, the 

following results were achieved:

 Treatment of wastewater with the three 

lagooning systems showed total removal of 

parasites and achieved 3-4 log unit reduction of 

E. coli. 

 A two-day delay between last irrigation and 

harvesting of lettuce achieved 77 percent

reduction of roundworm eggs on lettuce (from 

35 eggs/g to 8 eggs/g) and 1 log unit reduction 

for E. coli. 

 Twenty-six percent of farmers who were 

provided with masks, gloves, and boots had 

Figure 2

Loading narrow well with raw wastewater (Gaye and 

Niang, 2010)

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roundworm infection compared 50 percent of 

farmers who did not use protective equipment. 

 For disinfection of lettuce with bleach at the 

household level, 42 women have been involved 

in the test. We advised the use of one capsule 

(cap of the bottle) of bleach at 8° (around 6 mL 

= 0.2 fluid ounces) in 2.6 gallons (10L) of tap 

water (7.6 mg Cl/L) as a solution for disinfection 

of lettuce being soaked for 30 minutes before 

rinsing with tap water. The results have shown 

only 12 percent of women had lettuce still 

contaminated with E. coli. 

References

Gaye, M. Niang, S. 2010. Manuel des bonnes pratiques de 

l’utilisation saine des eaux usées dans l’agriculture urbaine. 

FAO/LATEU/Enda Rup. ISBN 92 91 30079 9. 

Gueye-Girardet, A. 2010. Evaluation des pratiques 

d’irrigation, de fertilization et d’application de pesticides dans 

l’agriculture periurbaine de Dakar, Sénégal. Thèse de 

doctorat. Faculté des Géosciences et de l’Environnement. 

Institut de Minéralogie et de Géochimie. Université de 

Lausanne.

Kass, A., Gavrieli, I., Yechieli, Y., Vengosh, A. and Starinsky, 

A., 2005. The impact of freshwater and wastewater irrigation 

on the chemistry of shallow groundwater: a case study from 

the Israeli Coastal Aquifer. Journal of Hydrology, 300(1-4): 

314-331. 

Leal, R.M.P., Herpin, U., da Fonseca, A.F., Firme, L.P., 

Montes, C.R. and Melfi, A.J., 2009. Sodicity and salinity in a 

Brazilian Oxisol cultivated with sugarcane irrigated with 

wastewater. Agricultural Water Management, 96(2): 307-

316. 

Ndiaye, M.,L. 2009. Impacts sanitaires des eaux d’arrosage 

de l’agriculture urbaine de Dakar (Sénégal). Terre et 

Environnement. Vol. 86. Insitut Forel/ Département de 

Minéralogie/Départemen de Géologie et Paléontologie. 

Section des Sciences de la Terre, Université de Genève.

Niang, S., Epoté, M., Mfoné, N., Pfeifer H. R., Ndiaye, M.,L., 

Gueye-Girardet, A., Diarra, K., Gaye, M. L., Dieng,Y., Niang, 

Y., Tall H. 2009. Effectiveness of three constructed wetlands 

for treatment of faecal sludge liquid at the experimental plant 

of LATEU-IFAN Ch.A.Diop/Dakar. Scientific report. FNS 

Switzerland. 

Pfeifer, H. R. and Niang, S. 2009. Use of wastewater in 

urban agriculture in the Dakar area, Senegal: an 

interdisciplinary study towards sustainablility Scientific Final 

report. Project FNS Switzerland 2005-2009.

Vengosh, A., 2003. Salinization and Saline Environments. In: 

B.S. Lollar (Editor), Environmental Geochemistry. Treatise 

on Geochemistry. Elsevier-Pergamon, Oxford.

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2012 Guidelines for Water Reuse

The Multi-barrier Safety Approach for Indirect Potable Use 

and Direct Nonpotable Use of NEWATER

Author: Harry Seah, MSc and Chee Hoe Woo, MSc (PUB Singapore)

Singapore-NEWater

Project Background or Rationale 

Singapore, being a small island city-state of about 270 

square miles (700 square km) and a population of 5 

million, has no natural aquifers or groundwater, and 

relies on rainfall from catchments and raw water 

imported from the neighboring Johor state in Malaysia. 

These sole water sources, however, are subject to the 

vagaries of nature, leaving Singapore vulnerable to 

water shortages.

In order to achieve a sustainable and robust water 

supply to meet increasing water demand, Singapore 

has diversified its water sources, termed the 4 National 

Taps, namely:

 Imported water from Johor, Malaysia

 Local catchment water

 NEWater

 Desalinated water

NEWater, high grade reclaimed water of drinking water 

standards, is key to achieving water sustainability in 

Singapore because of the multiplier effect through 

infinite recycling within the water system. 

Capacity and Type of Reuse 

Application 

Currently, NEWater is supplied from five NEWater 

factories in Singapore, with total capacities of 122 mgd 

(554,600 m3

/day). The total capacities of the NEWater 

factories are projected to reach some 192 mgd 

(873,000 m3

/day) by 2020.

Because it is ultra clean, NEWater is ideal for industry 

use, such as wafer fabrication processes. NEWater is 

mostly used for direct nonpotable use (DNU) into 

wafer fabrication and electronics industries, where the 

necessary water quality is more stringent than that for 

drinking, as well as in commercial and institutional 

complexes for air-conditioning cooling purposes. This 

frees up potable water for domestic use.

In addition, NEWater supplements Singapore's potable 

water supply via planned indirect potable use (IPU). 

Planned IPU involves blending NEWater with raw 

reservoir water, and then subjecting the blended water 

to the same conventional water treatment process as 

raw reservoir water to produce potable water. 

In February 2003, the Public Utilities Board (PUB), the 

national water agency of Singapore began pumping 2 

mgd of NEWater into reservoirs for IPU. It was 

increased progressively to about 2.5 percent of total 

potable water consumption in 2011.

Treatment Technology and Water 

Quality Standards 

NEWater is produced from treated used water 

(wastewater) that is purified further using advanced 

membrane technologies and ultraviolet (UV) 

disinfection, making the water ultra-clean and safe to 

drink.

The U.S. Environmental Protection Agency (EPA)

Primary and Secondary Drinking Water Standards 

(Safe Drinking Water Act) and WHO Drinking Water 

Quality Guidelines are the benchmarks set for 

NEWater quality. 

Project Management Practice 

To ensure that NEWater is of a quality safe for IPU, 

the multiple safety barrier approach is rigorously 

adopted through enforcement, plant design, plant 

operation, plant maintenance and water quality 

monitoring. 

This approach is audited bi-annually by an External 

Audit Panel comprised of 2 experts from the local 

tertiary institution and 5 overseas experts of 

international standing, and also by an Internal Audit 

Panel.

The multi safety barrier approach starts from 

thesource and extends to taps in households in the 

following stages:

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• Source control at the industries to ensure the 

used water received at the water reclamation 

plants (WRPs)1

• More than 85 percent of used water is used 

from domestic sources to provide additional 

safety through dilution

will be fully treated and 

provides a consistent good quality secondary 

effluent as feedwater for NEWater production;

• Comprehensive secondary wastewater 

treatment is used to provide consistent good 

quality effluent for NEWater production

• Microfiltration (MF)/Ultrafiltration (UF) process, 

reverse osmosis (RO) process, and ultraviolet 

(UV) disinfection in NEWater production

• Natural attenuation in surface reservoirs

• Conventional water treatment process of 

coagulation, flocculation, sand filtration and 

disinfection

The approach is further enhanced by a Sampling and 

Monitoring Programme (SAMP), which covers the 

entire delivery chain of NEWater to determine the 

suitability of NEWater for IPU and DNU; and a strict 

operating philosophy.

The SAMP is comprised of a comprehensive physical, 

chemical and microbiological sampling and analysis of 

water samples. To-date, 300 parameters are 

monitored including emerging contaminants of concern 

listed in the USEPA Priority List of Contaminants. 

The operating philosophy adopted in NEWater 

factories is based on operating with reference to the 

baseline performance of the plants. Such mode of 

operation is to maintain the water quality of the treated 

permeate close to the expected baseline readings, 

which are well within the WHO Drinking Water 

Guidelines and EPA Drinking Water Standards, during 

the daily operations.

NEWater Quality 

Since the operation of the first membrane 

(demonstration) plant began in year 2000 to produce 

 

1 Water Reclamation Plants in Singapore refer to treatment 

plants that provide secondary treatment to wastewater, via the 

activated sludge process.

NEWater, water analysis through grab sampling and 

on-line monitoring has shown consistently that 

NEWater quality is of drinking water standards, even 

as the membrane ages over the expected life span of 

5 years.

Table 1 shows the NEWater quality of selected 

parameters, out of the 300 parameters currently 

monitored for NEWater under the SAMP.

Institutional/Cultural Considerations 

An important part of the NEWater success story is its 

high public acceptance. This was achieved through a 

long and extensive public education program done in 

various phrases.

Before NEWater’s launch, extensive briefings were 

held for critical groups, which comprised of community 

leaders, business communities and government 

agencies. An educational tour was also organized to 

bring the media from Europe and the United States to 

observe the various places where water reuse has 

been practiced for many years. A documentary on the 

technology of NEWater and the water reuse 

experience of other countries was also produced and 

televised. 

Successes and Lessons Learned

NEWater is the product of years of investment in used 

water infrastructure and research on water 

technologies. Countries interested in water reuse on a 

municipal scale would need to have a comprehensive 

used water infrastructure in place. 

Accurately pricing the reclaimed water is also crucial 

for the reuse program's long term financial 

sustainability. 

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Table 1 Quality of NEWater since year 2000

Parameter Unit Analytical Methods Detection Limits Value

Physical Parameter Controls

TOC μg/L Sievers 820 TOC Analyser 20 40 to 100

SS Mg/L USEPA 160.2 2.5 <2.5

Turbidity NTU USEPA 180.1 0.1 <0.1

Trace Contaminants

Total estrogen μg/L NGCMS_1124 0.003 <0.003

Estrones (E1) μg/L NGCMS_1124 0.001 <0.001

17β-estradiol (E2) μg/L NGCMS_1124 0.001 <0.001

Ethinylestradiol (EE2) μg/L NGCMS_1124 0.001 <0.001

Ibuprofen μg/L LC-MS/MS 0.005 <0.005 

Naproxen μg/L LC-MS/MS 0.005 <0.005 

Gemfibrozil μg/L LC-MS/MS 0.005 <0.005 

N-nitrosodimethylamine (NDMA) ng/L PTV-GC/MS 2 <2 to 10

1,4 Dioxane μg/L USEPA 8270C 1 <1

Methyl Tertiary Butyl Ether (MTBE) μg/L USEPA 8260B 5 <5

Polychlorinated biphenyls (PCBs) μg/L USEPA 8082 0.2 <0.2

Public acceptance is crucial to the success of such 

projects. It is thus critical to translate complex 

technical jargon into terms that are easily understood 

by the public. In order to sustain people’s acceptance 

of NEWater, the NEWater Visitor Centre was set up in 

early 2003 to for the visitors to appreciate the 

philosophies and technologies used in the production 

of NEWater.

Moving forward, the production costs of NEWater can 

be further lowered through the adoption of new 

technologies, such as using membrane bioreactors 

(MBR), which will consume less energy, and will result 

in lower costs.

References

Asian Development Bank website. 2011. 

Retrieved on Sept. 6, 2012 from

 <http://www.adb.org/features/harry-seah-makingunthinkable-drinkable>. 

H. Seah, T. P. Tan, M. L. Chong and J. Leong. 2008. 

NEWater—Multi Safety Barrier Approach for Indirect Potable 

Use. Water Science & Technology: Water Supply, Vol 8 No 

5 pp 573–588

Public Utilities Board (PUB) website. 2011. Retrieved on 

Sept. 6, 2012 from 

 <http://www.pub.gov.sg/Pages/default.aspx>. 

U.S. Environmental Protection Agency (EPA). 2006. National 

Primary Drinking Water Regulations.

World Health Organisation. 2006. First addendum to 

Guidelines for Drinking-Water Quality (3rd edition). Vol.1 

Recommendations.

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2012 Guidelines for Water Reuse

Turning Acid Mine Drainage Water into Drinking Water: 

The eMalahleni Water Recycling Project

Author: Jay Bhagwan (Water Research Commission)

South Africa-eMalahleni Mine

Project Background or Rationale 

Population growth, rising service levels and economic 

development means that in many parts of South 

Africa, demand for water is growing faster than the 

supply available. 

In a first for South Africa, a pioneering public-private 

partnership (PPP) between eMalahleni Local 

Municipality and two leading coal mining companies 

(BHP Billiton and Anglo Coal) has led to the 

establishment of a major mine water reclamation plant. 

Acidic, saline, underground water from four nearby 

coal mines is treated and purified to drinking water 

standards and supplied to the Municipality. 

This type of collaboration between two large mining 

corporations has few precedents in South Africa, and 

highlights the growing importance attached to 

responsible environmental management. This 

innovative partnership has averted a water supply 

crisis in eMalahleni. At the same time, a major water 

contamination problem and environmental hazard has 

been transformed into a valuable resource which 

meets the needs of a range of users, safely and 

reliably. 

Capacity and Type of Reuse 

Application 

The eMalahleni Municipality is the main user and now 

receives 4.2 million gallons (16 megalitres) of safe, 

treated drinking water each day from the reclamation 

plant to boost domestic water supplies. Since April 

2009, this amount increased to 5.3 million gallons (20 

megalitres) per day. The outcome of this solution is 

based on ten years of research by Anglo Coal into 

water quality management options identifying a range 

of possible treatment technologies. No less than 13 

different treatment technologies to remove heavy 

metals and sulphates were evaluated in demonstration 

projects. In 2004, Anglo Coal short-listed seven 

technologies for further evaluation, and after extensive 

investigation, opted for a technology that relied on 

advanced membrane desalination. The key 

advantages of this technology were low life-cycle 

costs, a high rate of water recovery (greater than 99 

percent), and waste streams suitable for reprocessing 

and reuse.

A 31,700 gallons (120 m3

/day) pilot plant began in 

2005 to test the technology rigorously over a three 

month trial. Its performance exceeded expectations 

and Anglo Coal moved swiftly to develop a much 

larger plant, able to deliver 5.3 million gallons (20 

megalitres) a day of potable water, with further 

capacity to provide safe industrial-grade water for 

routine mining operations.

Water Quality Standards and 

Treatment Technology 

The treatment process is designed to produce water 

quality, which meets South African National Standard 

for Drinking Water Quality (SANS 0241 Class 0 

potable water) and uses the High Recovery 

Precipitating Reverse Osmosis (HiPRO) process from 

which low salinity product water is generated by the 

membrane process. This design’s chief characteristic 

is that it makes use of reverse osmosis to concentrate 

the water and produce supersaturated brine from 

which the salts can be released in a simple 

precipitation process. The project’s schematic is 

shown in Figure 1. 

This technology offers the following key advantages: 

 Very high recovery 

 Simple system configuration 

 Easy operation 

 Low operating costs 

 Low capital costs 

 Minimum waste 

The plant is designed to treat 6.5 mgd (25

megalitres/day) of acid mine drainage (AMD) with a 

recovery consistently greater than 99 percent, 

producing potable water with a guaranteed total 

dissolved solids (TDS) of under 450 mg/L (SABS 

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Class 0). The treated water is stored in two large 

concrete reservoirs before being pumped to a 

municipal reservoir for distribution to users in 

eMalahleni. Additional water is piped to a number of 

Anglo Coal sites for domestic use and for mining 

activities such as dust suppression. 

By-products of the treatment process are 26,400 

gallons (100 m3

) of brine and 100 tons (90,700 kg) of 

gypsiferous waste each day. Plastic-lined evaporation 

ponds are used to concentrate the brine further and 

Anglo Coal is exploring a number of cost-effective 

options for re-use. Gypsum-based wastes will be used 

in building construction, and the intention is to 

establish a market for gypsum-based building products 

on a large scale.

A second phase, completed in 2010, added a further 

2.1 to 2.6 mgd (8-10 megalitres/day) of industrial 

quality water for use on nearby mines and plans are in 

place to increase the capacity to 13 mgd (50 

megalitres/day).

Project Funding and Management 

Practices 

Financing of this option of treating acid mine water 

was way beyond the means of the municipality, and 

any proposed alternatives for augmentation had a long 

lead period before any water was supplied. The fact 

that the client eMalahleni Municipality realized this 

constraint and the constraint of managing such an 

advanced technology, the only lucrative option was 

this long term arrangement to purchase the water. The 

mines needed to continue to dewater to sustain its 

ongoing operation and where in a better position to 

raise the capital, based on the all-round benefits which 

were envisaged to accrue. The purchase of the treated 

water made the project viable for the mining 

companies, while meeting the municipality’s urgent 

need for additional water supplies. Ingwe Collieries 

owns South Witbank Colliery, where mining activities 

ended in 1969. In 2005, BECSA’s Ingwe Collieries 

entered a Joint Venture with Anglo Coal to develop the 

R296 million eMalahleni Water Reclamation Plant.

Successes and Lessons Learned 

The water reclamation plant and project offers a 

number of direct benefits. For the municipality, over 

and above an additional assured supply of clean 

water, perhaps the three most important benefits are 

cost-effectiveness, delivery of safe drinking water that 

requires no further treatment, and the technical 

expertise and financial resources of two major mining 

companies who funded the plants’ capital cost of 

nearly US $43 million. For the mines, there is a small 

financial loss in subsidizing this treated water of the 

cost of treatment is US $1.50 per 264 gallons (m3

) and 

sold to the Municipality for USm$1.00 per 264 gallons 

(m3

). However the environmental and social gains are 

much higher in that they have avoided serious future 

environmental damage.

References

Mr. Peter Gunther, Project Manager, Anglo Coal (personal 

communication)

P. Gunther and W. Mey. 2006. “Selection of Mine Water 

Treatment Technologies for the eMalahleni (Witbank) Water 

Reclamation Project,” unpublished paper presented at the 

2006 Bi-ennial WISA Conference. 

Figure 1

Schematic diagram of key component of the reclamation approach (Source: Gunther and Mey 2006)

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2012 Guidelines for Water Reuse

Durban Water Recycling Project

Author: Jay Bhagwan (Water Research Commission)

South Africa-Durban

Project Background or Rationale 

Water supply sources within South Africa are 

becoming ever more limited, while the need for 

alternative solutions is becoming increasingly more 

important with reuse becoming more attractive over 

traditional solutions. 

The city of Durban in the Ethekweni municipality, 

located on the east coast of South Africa, was faced 

with the challenge of sewage capacity constraints and 

the high cost of constructing a new outflow or marine 

outfall pipeline. They put together plans to increase 

capacity by building a duplicate sewer line, but found 

that the costs of wastewater disposal would be too 

high. The other option available was effluent recycling 

for reuse. However, even this option posed a financial 

and technical management challenge. The solution 

that emerged is an example of a Public Private 

Partnership (PPP) that harnesses the synergies of the 

partners to achieve an outcome that is unprecedented 

in the water industry in South Africa. The projects 

demonstrate innovative approaches to the sustainable 

development of water resources, minimization of water 

consumption and environmental pollution, and the 

achievement of technically challenging water and 

wastewater treatment goals. The result was the 

construction of a secondary waste water treatment 

plant and a water recycling plant, aimed at treating and 

supplying treated effluent to a level which was 

acceptable to an industrial recipient (Mondi Paper 

Mills) funded and managed through a partnership with 

the private sector Veola Water Services (VWS). This 

demonstrated that by pooling resources and expertise 

in a PPP, and by focusing on long-term sustainability 

goals, all participants can benefit, including the 

environment. 

The Durban Water Recycling Project demonstrates 

that innovative approaches to water resource management, environmental management, wastewater treatment technology and institutional arrangements can 

yield exceptional results. 

Capacity and Type of Reuse 

Application 

The resulting solution was a plant consisting of an 

upgrade of the existing activated sludge process from 

12.9 mgd to 19.9 mgd (50 megaliters/d to 77 

megaliters/d), the construction of a new 12.3 mgd 

(47.5 megaliters/d) tertiary plant (Figure 1), 

refurbishment of the high level storage tank and the 

installation of the reclaimed water reticulation system. 

This solution produced treated effluent (12.1 mgd or 

47 megaliters/d) for reuse in industrial application. 

Mondi uses the reclaimed water for the production of 

fine paper and is extremely sensitive to processed 

water quality and its impact on paper brightness.

Water Quality Standards and 

Treatment Technology 

The technology produces reuse water of a quality 

which has to comply with 32 contractually specified 

parameters based on regulatory requirements. The 

activated sludge process is a conventional design and 

serves to remove 95 percent of the incoming COD and 

98 percent of the incoming ammonia loads. Typically, 

activated sludge plant effluent COD and ammonia 

concentrations are 15 mg/L and 0.2 mg/L respectively. 

The first step in the tertiary treatment process is 

lamella settling. Poly Aluminum Chloride (PAC) is 

placed in the water leaving behind the lamella settlers 

and is employed for the removal of iron. The final 

Figure 1

Construction of the Durban Wastewater Recycling 

Plant (Photo credit: Ethekweni Metro Water Services)

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reclaimed water achieves iron levels of 0.04 mg/L, 

which is five times lower than the South African 

standards for class 1 potable water (SABS 241:1999). 

The dual media filtration step is the last solids removal 

barrier in the process. Iron precipitate is removed in 

the dual media filter. The final step is ozonation used 

to break up the remaining non-biodegradable organic 

compounds, including color causing compounds. 

Mondi Paper’s reclaimed water specification includes 

23 parameters that are measured in the South African 

potable standard (SABS 241:1999) of these 

parameters; Mondi’s specification meets or exceeds 

the potable standard for 77 percent of the parameters 

for class 1 potable water. In practice, VWS 

operationally meets or exceeds the Class 1 potable 

standard for 96 percent of the parameters. The Class 

1 potable water standard gives the water quality levels 

that are known to be acceptable for lifetime human 

consumption.

Project Funding, Management 

Practices, and Benefits 

The preliminary and primary wastewater treatment 

process is comprised of screening, degritting and 

primary settling operations; performed by Ethekweni 

Metro Water Services (EMWS). Meanwhile, the 

effluent from the primary settling tank is fed to the 

activated sludge plant operated by VWS. The funding 

of the capital for upgrade and new technologies, as 

well as the risks of meeting the water quality is 

undertaken by VWS under a 20 year production, 

operation and transfer concession. The incentive 

rested on the fact that the industry partner was 

prepared to accept a treated effluent water quality at a 

tariff, which was attractive and with offered high supply 

assurance. For the private sector it was a financially 

viable proposition, and for the municipality there were 

significant benefits to be achieved.

For EWS, the project has delayed capital investment 

for the increased marine outfall pipeline capacity; it 

also has delayed capital investment for future bulk 

potable water supply infrastructure. There was no 

capital investment and risks associated with the 

recycling plant; and a long term revenue stream from a 

levy raised on the production of recycled water was 

created thereby reducing cost of water services to 

Durban’s citizens.

For Mondi the benefits were a 50 percent reduction on 

normal industrial water tariffs, representing a 

significant cost saving in Mondi’s paper production. 

The project provided a higher assurance of water 

supply for the functioning of Mondi and greater 

security in terms of additional water requirements.

Successes and Lessons Learned

The success of the project demonstrated a true 

partnership between the public and private sectors and 

the success of the partnership lies in the mobilization 

of the inherent strengths of both sectors. Some of 

these key outcomes are as follows:

At operational capacity 12.3 mgd/47.5 megaliters/d) 

the reclamation plant will meet 7 percent of the city’s 

current potable water demand and will reduce the 

city’s treated wastewater output by 10 percent. EWS 

currently treats 121.3 mgd (470 megaliters/d) of 

wastewater. Of this volume, approximately 200 51.6 

mgd (megaliters/d) is discharged into the sea as 

screened and degritted wastewater. The reclamation 

project reduces the city’s total treated wastewater 

discharge by 10 percent and reduces the partially 

treated load on the marine environment by up to 24 

percent. Further, the volume of potable water saved on 

a daily basis afforded the opportunity to extend supply 

to up to 220,000 households in the greater Durban 

area.

Individually the water treatment steps employed in the 

Durban Water Recycling process are relatively 

standard in terms of water industry technologies. 

Together, however, the treatment steps create a highly 

specialized process, tailored specifically to meet the 

quality requirements of the main client, Mondi Paper 

Mills. The treatment of raw wastewater from both 

domestic and industrial sources to a potable standard, 

within the financial pressures of the business 

environment, is a significant technical achievement.

This 20-year concession project was the first PPP of 

its kind in South Africa. Within the South African 

context, the project broke new ground in its approach 

to manage and implement water projects and may be 

regarded as model for future PPPs in South Africa, 

and possibly elsewhere. The acceptance of PPPs and 

the involvement of the private sector in business 

opportunities for the provision of water services in 

South Africa are enhanced by the success of the 

Durban Water Recycling Project. 

This project has also changed the way industry in 

South Africa views wastewater. Sewage is no longer 

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regarded simply as a waste product, but a beneficial 

resource spurring many new initiatives which have 

unlocked innovation and technology. 

References and Sources

Fischer, P. (2001), Submission for the Visionary Client 

award 2001, South African Association of Consulting 

Engineers. Stewart Scott (Pty) Ltd.

Kuck, K., Freeman, M., Gisclon, A., Marche, O.(2002), Water 

Reclamation Project in an Environmentally Stressed Area. 

Technical poster paper presented at the 2002 WISA Biennial 

Conference.

SABS. (1999), South African Bureau of Standards 

Specification Drinking Water. SABS 241:1999 

Sagren, Govender., personal communication. General 

Manager – Veola Water, VWS Envig Pty Ltd., 

Sagren.govender@veoliawater.com. 

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2012 Guidelines for Water Reuse

Risk Assessment for Legionella sp. in Reclaimed Water at 

Tossa de Mar, Costa Brava, Spain

Authors: Rafael Mujeriego, PhD (Universidad Politécnica de Cataluña) and

Lluis Sala, (Consorci Costa Brava) 

Spain-Costa Brava

Project Background or Rationale 

Tossa de Mar is a Mediterranean coastal resort city in 

southern Costa Brava (Girona, NE Spain) and member 

of Consorci Costa Brava (CCB), the water supply and 

sanitation agency for Costa Brava. Tossa de Mar’s 

population goes from 6,000 people in winter to 60,000 

people in summer. Its drinking water use is 264 mgd 

(1 m3

/year), of which 20 percent comes from local 

sources and the remainder from external sources: 52

percent is groundwater from the Tordera river aquifer 

and 28 percent is desalinated water from Blanes 

desalination plant, both located 9 miles (15 km) 

southwest. Tossa de Mar was one of the leading cities 

in Costa Brava to recognize the benefits of turning 

wastewater into reclaimed water. Reclaimed water is 

now a new municipal water resource for non-potable 

use, with lower production and conveyance energy 

requirements than the conventional sources. 

Capacity and Type of Reuse 

Application 

The water reclamation plant (WRP) of Tossa de Mar 

has a capacity of 0.22 mgd [35 m3

/hr (840 m3/day)] 

upgradable to 0.89 mgd (140 m3

/hr). The current WRP 

capacity represents 13 percent of the potable water 

use during the peak tourist season. It includes: 

coagulation-flocculation, lamella settling, rapid sand 

filtration, and a combined disinfection process with 

sodium hypochlorite and UV light. Reclaimed water is 

stored in a 185,000 gallon (700 m3

) tank, where it is 

further chlorinated and mixed, and then pumped to the 

reclaimed water distribution system. Reclaimed water 

use for street cleansing and public garden irrigation 

began in 2003 by water tanks loading at a hydrant 

located at the doorstep of the WRP. By 2007 a 

reclaimed water distribution system was already in 

operation. The pipeline was brown in color with a blue 

plastic film that says “Atención: Agua no potable”. By 

mid 2011, the distribution system had reached a length 

of 3.5 miles (5.7 km) after an investment of US

$477,000 (365,000 €) from municipal and regional 

government sources. The distribution system provides 

reclaimed water to the main municipal services and 

landscape areas, fire hydrants, and other publiclyowned facilities, such as the county’s dog shelter 

(Figure 1) as well as to public spaces in new 

residential areas. In addition, landscape irrigation with 

reclaimed water at the Sa Riera Park is indirectly 

supplying recharge water flows to the local stream, 

avoiding its total summer desiccation and protecting its 

fragile aquatic ecosystems.

Water Quality Standards and 

Treatment Technology 

Spanish water reclamation and reuse regulations are 

established by Royal Decree 1620/2007. Reclaimed 

water quality is defined by four main parameters: 

parasitic helminth eggs, E. coli, suspended solids, and 

turbidity. Other micro-biological parameters, like 

Legionella sp. and physico-chemical parameters are 

applicable to specific uses of reclaimed water. 

Compliance is determined by the 90 percentile (P90) 

of the series of water quality parameters recorded 

during a water reuse period. Applicable limits for 

current reclaimed water uses in Tossa de Mar are 

Figure 1

Reclaimed water use at Tossa de Mar dog shelter 

(Photo credit: Lluis Sala)

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those for unrestricted urban use (Quality Use 1.2) with 

SS, turbidity, parasitic helminths and E. coli P90 

concentration limits below 20 mg/L, 10 NTU, 1 

egg/10L and 200 cfu/100mL, respectively. Future midterm plans include the supply of reclaimed water for 

irrigation of private gardens, which requires 

compliance with quality limits for unrestricted 

residential use (Quality Use 1.1): P90 values below 

10 mg/L for SS, 2 NTU for turbidity, 1 egg/10L for 

parasitic helminths and absence of E. coli (cfu/100 

mL).

Since 2007, CCB is conducting an extensive 

assessment of the overall Legionella infection risk 

posed by the use of reclaimed water for irrigation of 

urban and private gardens, following the Technical 

Guidelines for the Prevention and Control of 

Legionellosis established by the Spanish Ministry of 

Public Health and Consumer Affairs. These technical 

guidelines are used to assess such public health risk, 

based not only on the microbiological quality of the 

water (concentration of total aerobic bacteria, TAB < 

105 cfu/mL), but also on several other parameters and 

characteristics of the materials used in the distribution 

and application system, such as pipelines and 

sprinklers, among others. The upper limit of this index 

is 100 and anything below 60 is considered to be a 

“low infection risk” condition. 

The studies conducted since 2007 indicate that: 

1) TAB concentrations increase as water flows away 

from the point at the WRP where sodium hypochlorite 

is applied; 2) changes in TAB concentrations along the 

network system provide valuable information on how 

to manage the regrowth process and to maintain the 

network within the safety limits required by the 

Technical Guidelines; and 3) the overall infection risk 

resulting for spray irrigation in urban areas, 

considering the most unfavorable points of use 

(sprinklers) and under the most unfavorable 

microbiological conditions recorded, is just below 60 

units, the limit officially set for “low infection risk” 

conditions.

This monitoring program also provided useful 

information for determining whether re-chlorination is 

needed and where to apply it. Furthermore, Tossa de 

Mar complies with the requirements of Royal Decree 

865/2003 (2003) relative to the prevention and control 

of Legionellosis, by systematically cleaning and 

disinfecting all the sprinklers under its responsibility, 

whether they use drinking or reclaimed water.

Project Funding and Management 

Practices 

The investment completed so far amounts to US

$477,000 (365,000 €), which was provided by the 

Catalan Water Agency (CWA), CCB, Girona’s 

provincial government and the city of Tossa de Mar. 

Operation and maintenance of the water reclamation 

plant has been assured by CCB, while operation and 

maintenance of the reclaimed water distribution 

system has been assured by the city’s technical 

services. CCB is completing the official permitting 

process necessary to become a wholesale reclaimed 

water producer and supplier as prescribed by CWA. At 

that time, CCB will be able to establish the appropriate 

supply contracts with cities, which will be responsible 

for managing the technical and economic aspects of 

reclaimed water distribution to end users. In the event 

that CCB becomes a wholesale supplier, the 

responsibilities will be the same, as delegated under 

Spanish Water Reuse Regulations (RD 1620/2007).

Institutional/Cultural Considerations 

The use of reclaimed water in Tossa de Mar was 

prompted by the severe drought of the late 1990s and 

early 2000s. The high quality of reclaimed water and 

the clear benefits of its use for non-potable uses 

quickly raised a very positive perception from local and 

seasonal residents. Since then, CCB has promoted a 

high quality branding through CCB’s website, 

municipality website, and Facebook page, of the nonpotable use of reclaimed water in Tossa de Mar. 

Technical personnel wear white lab coats while 

conducting the on-site water testing and sampling, 

which has improved the citizen’s perception of the high 

microbiological and aesthetic quality of reclaimed 

water (Figure 2).

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Successes and Lessons Learned

Water scarcity and the favorable assessment of the 

energy balance of the municipal water cycle were the 

main factors for the project development. The quick 

and effective response of municipal services in close 

collaboration with CCB and the CWA were 

instrumental for the project success. The high 

reclaimed water quality, its high quality branding, the 

systematic follow-up studies and the educational 

programs implemented have all contributed to assure 

a very positive perception and acceptance from local 

and seasonal residents. The very favorable results of 

the Legionella risk assessment study have paved the 

way for the extension of the use of reclaimed water to 

irrigation of private gardens and possibly the supply of 

reclaimed water for toilet flushing in the very near 

future. 

References

Ministry of Public Health and Consumer Affaires (2003). 

Royal Decree 865/2003 on the Hygienic and Public Health 

Criteria for the Prevention and Control of Legionellosis. BOE 

no. 171, pp. 28055-69. Retrieved on Sept. 7, 2012 from 

<http://www.boe.es/boe/dias/2003/07/18/pdfs/A28055-

28069.pdf>.

Ministry of Public Health and Consumer Affairs. Technical 

Guidelines for the Prevention and Control of Legionellosis in 

Facilities. Retrieved on Sept. 7, 2012 from

<http://www.msc.es/ciudadanos/saludAmbLaboral/agenBiolo

gicos/guia.htm>.

Ministry of the Environment, Rural and Marine Affaires 

(2007). Royal Decree 1620/2007 about the Spanish 

regulations for water reuse. Boletín Oficial del Estado núm. 

294, pp. 50639-61. Retrieved on Sept. 7, 2012 from

<http://www.boe.es/boe/dias/2007/12/08/pdfs/A50639-

50661.pdf>.

Water Reuse Project of Tossa de Mar, CCB (2011). 

WateReuse Barcelona 2011. Retrieved on Sept. 7, 2012 

from 

<http://www.waterbcn2011.org/download/Water%20Reuse%

20Project%20of%20Tossa%20de%20Mar.pdf>.

Figure 2

Reclaimed water quality monitoring in Tossa de Mar 

(Photo credit: Lluis Sala)

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2012 Guidelines for Water Reuse

Sam Pran Pig Farm Company: Using Multiple Treatment 

Technologies to Treat Pig Waste in an Urban Setting 

Authors: Pruk Aggarangsi, PhD (Energy Research and Development InstituteNakornping, Chiang Mai University, Thailand)

Thailand-Pig Farm

Project Background or Rationale 

In Thailand, there are numerous pig farms which must 

treat the pig effluent in order to meet the standards set 

by the Pollution Control Department (PCD) of 

Thailand's Ministry of Natural Resources and 

Environment (MNRE) (MNRE, 2005). This case study 

illustrates the use of Upward-flow Anaerobic Sludge 

Blanket (UASB) reactors as adopted by one pig farm, 

the Sam Pran Pig Farm, in Nakhon Pathom Province, 

located approximately 40 miles (65 km) southwest of 

Bangkok.

Capacity and Type of Reuse 

Application 

The Sam Pran Pig Farm Company raises between 

5,000 and 8,000 pigs at a time, ranging from 22 to 220 

pounds (10 to 100 kg) each, with an average size of 

130 lbs (60 kg). The pig farm has 18 single level, open 

pig stables with an average size 45 ft by 280 ft (13.5 m 

by 85 m). The pigs generate solid fecal matter at a rate 

of 860 lb/day (390 kg/day) and liquid waste including 

urine, stable wash water and fecal liquid run off at a 

rate of 29,000 gallons (110 m3

/day). All waste 

generation is collected daily. 

The farm utilizes two sets of channel digesters (CDs) 

each integrated with a UASB reactor plus additional 

subsequent treatment steps (including aeration and 

water hyacinth ponds) to process wastewater. These 

reactors produce biogas (methane and carbon dioxide) 

via an anaerobic decomposition process that 

eliminates more than 90 percent of the biochemical 

oxygen demand (BOD) and chemical oxygen demand 

(COD). The system also removes most solids from the 

wastewater. The waste is converted into fertilizer, 

biogas and water for washing the pig barns.

Figure 1

Composition of the system at Sam Pran (from top to 

bottom): channel digester and solids drying beds for 

use as fertilizer, aeration tank, water hyacinth pond, 

and biogas-fueled generator.

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Treatment Technology 

The top industrial uses of UASBs include treatment of 

wastewater from breweries, distilleries, other beverage 

and fermentation operations, the food processing 

industry, and pulp and paper operations. While UASBs 

are generally used in many applications for rapid 

treatment of wastewater with high BOD, the treatment 

system for Sam Pran farm is specially designed by 

Chiang Mai University to cope with specific pig waste. 

The system consists of one channel digester with 

serial-integrated UASB module running at 6-7 days 

Hydraulic Retention Time (HRT). 

Wastewater Treatment System 

Performance 

After a 6-month system stabilization period, the 

performance of the system was measured. The 

system produced 440-880 lbs (200-400 kg) per day of 

fertilizer, 7,000 to 14,000 cubic feet (200-400 m3) 

biogas per day (which produces 300-600 kW.h per day 

of electricity) and 26,400 gallons (100 m3) per day of 

recycling water acceptable for washing the pig barns. 

The performance of the treatment system is 

designated in Table 1. 

Project Funding and Management 

Practices 

In 2004 when Sam Pran farm initialized the project, a 

total investment cost of the digester, approximately 3.0 

million THB ($100,000 USD), 20 percent is funded by 

Energy Conservation Fund through Livestock biogas 

subsidizing program by Thailand Ministry of Energy. 

The farm owner has to cover the rest of the investment 

including the land and electricity generation 

equipment.

Institutional/Cultural Considerations 

The project seems to be a best model in practice for 

collaboration between community, local government 

and academia to find and implement the best solution 

to this difficult waste management problem.

Successes and Lessons Learned 

Sam Pran farm founded their business more than 30 

years ago in the area designated as the pig raising 

community away from the residential area. The growth 

of city's population forced an expansion of the 

residential area in all directions. Currently, Sam Pran 

farm is located in the city's municipal area. Thus, the 

farm has to conform to strict regulations in terms of 

effluent and odor control in order to continue their 

business. Anaerobic digesters were their only option in 

both the technical aspect and land use effectiveness. 

References

Ministry of Natural Resources and Environment. 2005. Pig 

Farm Effluent Standards, Royal Thai Government Gazette, 

Vol. 122, Sec. 125-, December 2005, pp. 14-17. 

Energy Research and Development Institute-Nakornping, 

2008, Internal Report on Biogas Subsidizing Program.

Table 1 Performance of installed CMU CD+UASB System in Sam Pran Farm

Parameters

Digester 

Influent

Flow Leaving 

UASB towards 

Aeration Tank

Final 

Discharge

Thailand Waste Water 

Standard 

pH 7.1 7.7 7.8 5.5-9.0

BOD5 (mg/L) 3,245 86 327 100

TCOD

(mg/L) 1,513 306 65 400

TKN (mg/L) 463 397 261 200

TSS (mg/L) 812 150 59 200

TKN = Total Kjehldahl nitrogen (i.e. the combination of organically bound nitrogen and ammonia in 

wastewater) 

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2012 Guidelines for Water Reuse

Evaluating Reuse Options for a Reclaimed Water Program 

in Trinidad, West Indies

Authors: Matt McTaggart, P.Eng, R.Eng; Jim Marx, MSc, P.E.; and 

Kathy Bahadoorsingh, PhD, R.Eng (AECOM)

Trinidad and Tobago-Beetham

Project Background or Rationale 

The island of Trinidad is the most southern island of 

the Caribbean and covers an area of approximately 

1,841 mi2 (4,768 km2

). Trinidad’s economy is primarily 

energy based and there are industrial estates 

concentrated in the southern section of the island. The 

Beetham Wastewater Treatment Plant (WWTP) 

effluent could therefore provide a supply that is not 

severely affected by seasonal variation, as well as 

reduce the demand on high quality potable water in 

applications where appropriately treated, non-potable 

supply could suffice. There is also a thriving 

agricultural sector with large farms located throughout 

the island. 

The island has experienced continued economic 

growth over recent years and consequently there was 

an increasing demand for water. This steady increase 

in water demands prompted the Government of the 

Republic of Trinidad and Tobago (GORTT) together 

with its Water and Sewerage Authority (WASA) to 

capitalize on the valuable resource available from the 

Beetham WWTP, which is located towards the 

northwestern section of Trinidad just east of the capital 

city of Port of Spain.

Capacity and Type of Reuse 

Application 

The Beetham WWTP is the largest wastewater 

treatment plant in Trinidad. The plant treats 

approximately 21 mgd (80 ML/d) of wastewater 

collected from Trinidad’s capital city Port of Spain and 

its environs. The wastewater entering the plant 

undergoes preliminary treatment comprising screening 

and grit removal. It then receives secondary treatment 

from an activated sludge process that incorporates 

nitrogen removal. Conventional gravity clarifiers 

provide solid-liquid separation and the clarified effluent 

undergoes ultraviolet disinfected before it is 

discharged to the Black River that flows to the Gulf of 

Paria.

The Beetham WWTP, which was commissioned in 

2005, consistently meets its effluent design criteria. 

Table 1 summarizes the average effluent quality for 

the period 2005 to 2010 together with the plant’s 

design criteria.

Table 1 2005 - 2010 average WWTP influent, effluent 

data compared to design criteria

Parameter Influent Effluent Design 

Criteria

Flow, ML/d 78 75 80

pH 7.2 7.7 6-9 

TSS, mg/L 163 4 20

BOD, mg/L 125 2 20

COD, mg/L 301 18 - 

NH4-N, mg/L 15.4 0.2 - 

Total P, mg/L 2.9 1.7 - 

Residual Chlorine, mg/L 0.01

Fecal Coliform, #/100 mL 85 200

The flow data from the Beetham WWTP over the 

period July 2005 to December 2010 indicated that the 

plant maintained an average effluent flow near its 

design capacity of 21 mgd (80 ML/d) throughout the 

dry season. This is in contrast to the monthly average 

rainfall records as shown in Figure 1. 

Figure 1

Average WWTP effluent flow and monthly average 

rainfall

0

50

100

150

200

250

300

0

20

40

60

80

100

120

140

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Rainfall (mm)

Effluent Flow (ML/d)

Month

Rainfall Effluent 

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The projected water demand for 2015 shows domestic 

users as having the greatest demand of 195 mgd 

(736 ML/d)followed by industry at 65 mgd (245 ML/d) 

and then irrigated agriculture at 7 mgd (27 ML/d) 

(WRA, 2001; WASA, 2007). The options therefore 

focused on reuse applications in urban, agricultural, 

industrial and indirect potable reuse.

Water Quality Standards and 

Treatment Technology 

Currently there are no local reuse water quality 

standards or regulations for Trinidad and hence, 

standards for the Beetham Reuse Project were 

adopted from the United States, specifically the states 

of California and Florida. These states were selected 

because they have significant reuse programs in place 

and well established regulations to govern these 

programs. 

Project Funding and Management 

Practices 

Based on the reuse possibilities and the required 

treatment level, reuse options were developed that 

considered the location of the end users, the route 

taken to deliver the reclaimed water, and the water 

quality requirements of the end users. Four general 

options were formulated as follows:

Option 1: Reclaimed Water (RW) delivered to 

industrial users via marine routes

Option 2: RW delivered to primarily industrial end 

users plus some agricultural end users via 

marine route and then overland

Option 3: RW delivered to primarily industrial end 

users plus some agricultural end users via 

overland routes

Option 4: RW delivered to agricultural, industrial and 

other end users via overland routes

Three end uses were evaluated within each option as 

follows:

a. Unrestricted urban reuse, medium quality 

industrial

b. Food crop irrigation, indirect water supply 

augmentation, general purpose industrial

c. Aquifer recharge by injection

Life-cycle cost analyses were performed for the 12 

alternations. Two funding mechanisms were 

evaluated, private equity in the form of build-ownoperate-transfer (BOOT) contract, and funding by 

GORTT. Non-monetary decision variables also 

included technical, social, and environmental factors 

that would influence the reuse program 

implementation. These were ranked using a numerical 

scoring system. 

The highest rated option, based on a benefit to cost 

ratio, was a multi-user concept that would provide 

reclaimed water for food crop irrigation, indirect 

potable water augmentation, and general purpose 

industrial use.

Institutional/Cultural Considerations 

While reclaiming WWTP effluent for reuse purposes is 

new to Trinidad, it appears the concept would be 

acceptable to the general public based on a short-term 

project in which secondary effluent was dyed, 

chlorinated, and used for urban irrigation during a 

significant drought in 2009. However, the program has 

not moved forward. One of the biggest issues keeping 

the program from being implemented is the outdated 

water rates that undervalue potable water such that a 

true comparison with alternative sources cannot be 

made. 

Successes and Lessons Learned

Implementation of the Beetham Reuse Program was 

put on hold in 2011 for several reasons including the 

high cost of distributing reclaimed water to the 

potential end users and the election of a new 

government that had different priorities and 

approaches for solving the water shortage problem. It 

appears that the best chance for reviving the program 

would be to identify a major user near the WWTP that 

could be economically supplied with RW to meet their 

demands. The most promising user identified to date is 

the Trinidad and Tobago Electrical Commission. They 

are planning to build a new power plant about 

1.2 miles (2 km) east of the WWTP and reclaimed 

water would be an ideal cooling medium for the new 

facility.

References

WASA (2007) Future Water Supplies for Trinidad and 

Tobago: The Challenges and the Solutions.

WRA (2001) National Report on Integrating the Management 

of Watersheds and Coastal Areas in Trinidad and Tobago. 

Prepared for the Ministry of the Environment, March 2001. 

Retrieved on Sept. 7, 2012 from 

<http://www.oas.org/reia/iwcam/pdf/trinidad%20and%20toba

go/trinidad%20and%20tobago%20national%20report.pdf>.

E-113
2012 Guidelines for Water Reuse

Langford Recycling Scheme

Author: Afsaneh Janbakhsh, MSc, Cchem, MRSC, Csci (Northumbrian Water Ltd, UK) 

United Kingdom-Langford

Project Background or Rationale 

Essex & Suffolk Water (ESW) is in the southern 

operating area of Northumbrian Water Limited (NWL) 

which supplies a population of approximately 1.5 

million people with potable water. In response to a 

supply deficit, Essex & Suffolk Water identified the 

Langford Recycling Scheme (the Scheme) as a new 

resource. The scheme involves diverting the 

Chelmsford Sewage Treatment Works (CSTW) 

effluent from the Blackwater Estuary to the Langford 

Recycling Plant (LRP). The reclaimed water is then 

discharged in the River Chelmer at Scotch Marsh to be 

abstracted 8 km downstream for drinking water supply. 

In April 2000, ESW was granted a permit by the UK 

Environment Agency (EA) to discharge reclaimed 

wastewater, originally from CSTW, into the river 

Chelmer at Scotch Marsh, Ulting. In addition, the 

Company was allowed to vary its abstraction license to 

benefit from this extra water. The granting of the 

permits effectively gave approval for the construction 

of the wastewater recycling plant for indirect potable 

reuse with an output of up to 10.5 mgd (40 ML/d). The 

scheme has been operating successfully since 2003, 

providing additional flow in the river Chelmer during 

the periods of low flow. 

Capacity, Type of Reuse Application 

and Treatment Technology 

The purpose of the recycling scheme is indirect 

potable reuse. Although the LRP is licensed to recycle 

up to 10.5 mgd (40 ML/d) the average daily output is 

normally between 5.3 to 6.6 mgd (20-25 ML/d). During 

drought periods, these volumes represent up to 70

percent of the raw water available in the River 

Chelmer at ESW’s drinking Water’s intake. The 

scheme is normally operated from April to November 

when the temperatures support the biological 

treatment process at the LRP. From October 2003 to 

November 2011, a total of 3.47 billion gallons 

(13,139.7 ML) of reclaimed water was produced for 

indirect potable reuse. The highest production was 

during the drought periods during 2005 to 2006 and 

2010 to 2011. 

The advanced treatment process at the LRP includes 

the following processes: 

 Biological nitrification-denitrification 

 Chemical phosphorus removal 

 UV disinfection

The treated reclaimed water from the LRP is 

consistently much higher quality than the receiving 

river water in terms of chemical and bacteriological 

contaminants. 

Water Quality Standards 

The EA consent conditions for the LRP aim to protect 

the receiving stream water quality; the treated water 

quality standards are summarized in Table 1. The 

treated reclaimed water meets all established water 

quality standards (Table 2) and as such, the LRP is 

considered the tertiary stage of the CSTW. In addition, 

the following consent limits apply to the discharge: iron 

2mg/L, copper 40mg/L, and nonylphenol 4.0 μg/L. 

Environmental Impact 

Environmental monitoring was conducted to assess 

the impact of reclaimed water discharge on the 

receiving stream. The monitoring program included 

weekly chemical and bacteriological sampling as well 

as monthly macrophytes, phytoplankton and 

invertebrate monitoring. In addition, the LRP final 

effluent and Clemsford effluent were tested for 

possible endocrine disruption effects using fish 

bioassays. Monthly algae and zooplankton surveys 

were carried out at the Hanningfield Reservoir 

Environmental impact assessments on the estuary (a 

Ramsar site, a Site of Special Scientific Interest, a 

Special Area of Conservation and a Special Protection 

Area) from where the wastewater is diverted consisted 

mainly of studies on marine invertebrates and wildfowl 

that preyed upon them. The impact of increased water 

abstraction on siltation in a local port on the estuary 

was also evaluated. In order to mitigate the effect of 

diverting the wastewater, ESW carries out annual 

dredging at Maldon Port to reduce the impact of 

siltation.

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Project Funding and Management 

Practices 

Funding for the studies, promotion and building of the 

LRP was through the UK water industry’s normal 

regulated business planning process. The funding was 

obtained through price increases for potable water with 

this particular scheme having a low capital expenditure 

(CAPEX) cost but a higher than normal operational 

expenditure (OPEX) cost because the practice of 

using reclaimed water as a potable water source 

requires additional treatment that is not normally 

required for a conventional raw water source.

Institutional/Cultural Considerations 

This is the first example of a planned indirect potable 

reuse scheme in Europe. There were no precedents 

that could be used for justification of the project and a 

great deal of effort was required to demonstrate to the 

government, regulators and the public the value and 

safety of the proposed project. The success of the final 

scheme was a result of significant stakeholder 

engagement with customer representative groups and 

customers. This included the purchase and fitting of a 

mobile information workshop that was taken to all 

areas that would receive the potable water. 

Successes and Lessons Learned

Years of baseline and pilot plant data that 

demonstrated improvement to water quality were key 

to securing the reuse license. However, even with 

solid scientific information, public acceptance is not a 

given and early engagement and clear communication 

with project stakeholders was essential to project 

success. The solid science, regulatory coordination 

and public engagement were all important components 

of this project that promotes sustainable water use, 

enhances the aquatic environment through a reduction 

in polluting discharges and mitigates the impacts of 

drought. 

References

A.Janbakhsh, 2011, Langford Recycling Scheme; 10 year 

review, Essex & Suffolk, Water Resources Department. 

S.J. Wishart, S.W. Mills, J.C. Elliott, 2000, Considerations for 

recycling sewage effluent in the UK, vol. 14, pp. 284-290, 

J.CIWEM. 

V. Lazarova, B Levin, J.Sack, G. Cirelli, P. Jeffrey, H. 

Muntau, M. Salgot, F. Brissaud, 2001, Role of water reuse 

for enhancing integrated water management in Europe and 

Mediterranean countries, vol.43, No 10, pp 25-33. Water 

Science and Technology.

D.Walker, 2000, Oestrogenicity and wastewater recycling, 

Experience from Essex and Suffolk Water, vol.14, pp. 427-

431, J. CIWEM.

J. Harries, A.Janbakhsh, S.Jobling, J. Sumpter, C. Tyler, 

1999, Estrogenic potency of effluent from two sewage 

treatment works in the United Kingdom, vol. 18, No. 5, pp. 

932-937, Environmental Technology and Chemistry.

Table 1 Water framework directive standards

Parameter 90 Percentile 95 Percentile Maximum Annual Mean

BOD 10 mg/L 20 mg/L 3.2mg/L

Ammonia 2 mg/L 7mg/L 0.28 mg/L

Suspended Solids 20 mg/L 3.1 mg/L

SRP 1,000 μg/L 255 μg/L

Total Nitrogen 15 mg/L 3.9mg/L

Dissolved Oxygen (percent saturation) >70 % >40% 89 %

Table 2 Urban wastewater treatment directive (UWWTD) standards 

UWWTD limit Annual Average Removal Rate Limit

LRP Annual Mean Removal 

Rate

BOD 25mg/L 70-90% 96%

COD 125 mg/L 75% 85%

Total phosphorus 1000 μg/L 80% 96%

Total Nitrogen 70-80% and 57% by LRP only 83% total, 72% by LRP only

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2012 Guidelines for Water Reuse

Water Reuse as Part of Holistic Water Management in the 

United Arab Emirates

Authors: Rachael McDonnell, PhD (International Center for Biosaline Agriculture) 

and Allegra K. da Silva, PhD (CDM Smith)

United Arab Emirates-Abu Dhabi

Project Background or Rationale 

As a region, the Middle East and North Africa (MENA) 

is the driest in the world, with only 1 percent of the 

globe’s freshwater resources. About 43 percent of 

wastewater generated in the MENA region is treated 

with a wide range in the percent of wastewater treated 

between countries (Qadir et al., 2010). While several 

countries in the region have very little wastewater 

treatment, other countries with the financial resources 

have a very high percentage of treatment and treat 

wastewater to very high quality for reuse. In countries 

that are dependent on desalination to supply major 

portions of their water demands, water reuse can be a 

relatively lower energy and cost alternative. As a 

region, approximately one quarter of all wastewater 

generated is treated and reused. The Abu Dhabi 

emirate has been one of the few leaders in the region 

with the commitment to implement substantial 

wastewater treatment and reuse programs utilizing 

over seventy percent of this resource. 

Abu Dhabi’s mean annual rainfall is extremely low—

only 32 mm (1.25 inches) per year. Water resources in 

the United Arab Emirates (UAE) have traditionally 

been met through shallow groundwater wells. 

However, rapid economic development and population 

increases over the last three decades have 

dramatically increased the emirates’ water demands. 

About 70 percent of the emirate’s water comes from 

brackish groundwater. This non-renewable resource 

has been used predominantly to support expansions in 

agriculture. Salinization of some aquifer resources and 

soils has resulted (Murad et al., 2010 and Al-Katheeri 

et. al, 2008). The UAE’s groundwater deficit is largely 

met by desalinated water (24 percent) and the reuse of 

treated wastewater for agriculture and landscape 

irrigation (6 percent). 

To improve the current water situation, the emirate of 

Abu Dhabi has adopted a water resources master plan 

and a water reuse strategy to maintain the emirate’s 

water security. 

Water Reuse as Strategy in Abu Dhabi 

Abu Dhabi Emirate is the largest of the seven emirates 

that compose the UAE. Abu Dhabi’s urban population 

(1.4 million) is projected to increase by an average of 

50 percent every seven years up to 2030. In 2003, 

water consumption in Abu Dhabi was 92.5 gallons 

(350 litres) per capita per day, among the highest rates 

in the world (Global Water Intelligence, 2009). 

Water reuse has been practiced in Abu Dhabi for over 

a decade for landscape irrigation. As of 2010, 

reclaimed water adds about 6 percent to overall water 

supplies (EAD, 2010).

The formulation of Abu Dhabi Water Resources 

Master Plan (Pitman et al., 2009) published by the 

Environment Agency Abu Dhabi (EAD) in 2009 was a 

major strategic step towards achieving its vision for a 

sustainable future for Abu Dhabi. The plan identified 

existing total water availability and demand and 

projected forward to examine future conditions and 

options. To address the lack of renewable freshwater 

resources, the plan recommended water reclamation 

to minimize environmental costs of desalination, 

particularly energy consumption and greenhouse gas 

emissions.

Taking the water resources planning process forward, 

EAD recently established a bold wastewater reuse 

strategy for the Emirate of Abu Dhabi (EAD, 2010) that 

was developed by the International Centre for 

Biosaline Agriculture (ICBA). This reuse strategy 

provides a roadmap for diversifying the application of 

recycled water in the emirate for agriculture, forestry, 

and amenities. The strategy identifies the opportunities 

for reuse in the emirate, technical aspects of reuse 

(including protecting public safety, and the 

incorporation of both decentralized and centralized 

systems). The strategy also addressed associated 

institutional and regulatory issues. Since reclaimed 

water is such a valuable resource in Abu Dhabi, the 

strategy specifically outlines licensing approaches and 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Figure 1

Predicted water supply by sectors in UAE 

high efficiency farming to avoid profligate use of 

reclaimed water in agriculture.

The water reuse strategy also calls for several 

implementation components, including:

1. A survey of public acceptance

2. A wastewater market assessment to help design 

systems that achieve the best possible economic 

conditions

3. A commitment that the design and location of 

future wastewater treatment plants should take 

potential reuse as the starting point

4. A commitment to view water reuse as an element 

in a broader water management approach which 

also encompasses demand management, 

conservation, and a recognition of the economic 

value of water

International and local expertise was enlisted in ICBA’s 

development of this master plan, from both the public 

and private sectors, involving all relevant agencies, 

including the Regulation and Supervision Bureau 

(RSB), the Abu Dhabi Sewage Services Company 

(ADSSC), and the Abu Dhabi Food Control Authority 

(ADFCA). This integrated approach to stakeholder 

involvement is key to the success of the strategy.

Matched with this policy commitment is a strong 

financial commitment to urban regeneration, including 

water and wastewater system improvements. The 

overall strategic vision for Abu Dhabi, Plan 2030, 

includes a planned total investment of over $1 trillion in 

infrastructure, with a commitment to state-of-the-art 

wastewater infrastructure (Stedman, 2010). Where 

wastewater treatment will be installed in Abu Dhabi, 

the focus will be on reuse, driven by the opportunities 

presented by water scarcity. Reclaimed water is 

expected to provide around 10-13 percent of overall 

water supplies by 2030, by progressively substituting 

reuse for expensive desalinated water and rapidly 

dwindling fresh groundwater supplies (EAD, 2010). 

The two main wastewater treatment plants that 

currently serve the emirate, at Mafraq and Al Ain, have 

been operating above design capacity. Four new large 

WWTP are currently being built in the Emirate of Abu 

Dhabi which will add a treatment capacity of 225 mgd 

(850,000 m3

/day) to serve more than 3 million 

inhabitants (Al Wathba Veolia Besix Waste Water, 

2012). This new infrastructure has been designed with 

state-of- the-art technologies enabling 100 percent 

reuse of the wastewater treated for irrigation purposes.

Figure 1 shows the predicted water supply by sectors 

in UAE through 2030.

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Types of Reuse Applications 

For over a decade, Abu Dhabi has implemented reuse 

for irrigation under the municipality’s Sewerage 

Projects Committee, under the direction of His 

Highness Sheikh Zayed Bin Sultan Al Nahyan. An 

investment of around U.S. $149 M (547.5 M UAE 

Dirhams) has resulted in an irrigation system using 

reclaimed water from the Mafraq wastewater treatment 

facility to irrigate approximately a quarter of the island 

section of the city’s area to create a green oasis in the 

city. This has generated fresh water savings and a 

series of ecological, social, and economic benefits. 

The greening of the city has enhanced the urban 

environment and offset pollution and carbon 

emissions. During peak summer demand, irrigation 

requirements surpass the volume of reclaimed water 

generated by Mafraq and is supplemented with 

valuable potable water. The city has initiated a series 

of studies to improve the system through data 

collection, modeling, system upgrades including 

strategic storage, landscape redesign, and data 

management (Shepherd, 2003). 

Water reuse is also a key opportunity to achieving 

adequate long-term storage capacity. Artificial aquifer 

recharge on a large scale could be beneficial to help 

the emirate achieve emergency water supply storage. 

Existing pilot projects are examining the feasibility of 

aquifer recharge using reclaimed water (Al-Katheeri et 

al., 2008).

While under the new Abu Dhabi wastewater reuse 

strategy, reclaimed water will substitute about 10 

percent of the emirate’s water supply, projected 

demands will be 40 percent greater than potential 

supplies by 2025, requiring improvements in water use 

efficiency and careful targeting of highest added-value 

reuse (Shepherd, 2003). 

Water Quality Standards and 

Treatment Technology 

One important component of Abu Dhabi’s approach 

has been the setting of clear regulatory standards for 

trade effluent discharge control, and recycled water 

and biosolid products and use by the regulator, the 

RSB. Two categories are defined with the strictest 

standards defined for end uses where the public are 

more exposed such as in flushing toilets and urban 

irrigated areas.

Project Funding and Management 

Practices 

The emirate of Abu Dhabi has committed all the 

investment to set the national policies and water reuse 

strategy. In addition to significant commitments to the 

development of new infrastructure, $13 billion of 

private investment has also been attracted (GWI, 

2009).

Successes and Lessons Learned

Coordinated efforts between the various agencies 

involved in water management in Abu Dhabi has 

shown clear leadership in making a strong 

commitment to including water reuse as part of its 

overall water resource strategic planning for the 

growth and sustainability of the emirate. Through the 

Abu Dhabi Technical Committee for Wastewater, 

activities between different institutions and users 

involved in reuse have been harmonize, and may 

become a focal point for water reuse advocacy, public 

education, and outreach (EAD, 2010). Also by 

including provisions for wastewater reuse 

infrastructure development at the outset of new 

developments, the most financially and 

environmentally sound solutions can be incorporated 

for both handling wastewater, but also addressing 

water demands.

References

Abu Dhabi Emirate. (2006) Water Resources Statistics 2006. 

Al-Katheeri, E. S. 2008. "Towards the establishment of water 

management in Abu Dhabi Emirate." Water Resources 

Management 22(2): 205-215.

Al Wathba Veolia Besix Waste Water (2012) “Water 

Conservation in Abu Dhabi.” Accessed online May 9, 2012 at 

http://www.istp2.ae/en/Missions/History_of_wastewater_treat

ment/. 

Environment Agency Abu Dhabi (2010). A Strategy for the 

Reuse of Wastewater: Emirate of Abu Dhabi. Volume 1 – 

Main Report.

Global Water Intelligence. 2009. Water Market Middle East 

2010.Global Water Intelligence. London, United Kingdom.

Murad, A. A. 2010. "An Overview of Conventional and NonConventional Water Resources in Arid Region: Assessment 

and Constrains of the United Arab Emirates (UAE)." Journal 

of Water Resource & Protection, 2(2): 181-190. 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Qadir, M., A. Bahri, et al. 2010. "Wastewater production, 

treatment, and irrigation in Middle East and North Africa." 

Irrigation and Drainage Systems, 24(1): 37-51.

Ratcliff, R., Minney, I., Smolenska, K., and Duquez, R. 

(2007) "Closing the Loop Reuse in Dubai." Proceedings of 

the Water Environment Federation, (10): 7532-7545.

Pitman, K., McDonnell, R. A., and Dawoud, M. (eds). 2009. 

Abu Dhabi Water Resources Master Plan. Environmental 

Agency Abu Dhabi. UAE. 

Shepherd, P. 2003. "Seeing green." Water 21 Magazine of 

the International Water Association (DEC.): 39-41.

Stedman, L. I. S. 2010. "Project progress in the Middle East 

and Africa." Water 21 Magazine of the International Water 

Association, (4): 33-37.

Ministry of Environment and Water (2010). United Arab 

Emirates Water Conservation Strategy. 

Water21. (2011). "Pilot project for Dubai." Water 21 

Magazine of the International Water Association 2011(3): 24-

24.

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2012 Guidelines for Water Reuse

Wastewater Reuse in Thanh Tri District, 

Hanoi Suburb, Vietnam

Authors: Lan Huong Nguyen, MSc; Viet-Anh Nguyen, PhD; and Eiji Yamaji, PhD 

(Hanoi University of Civil Engineering, Vietnam) 

Vietnam-Hanoi

Project Background or Rationale 

In Vietnam, a large number of urban and peri-urban 

farmers rely on wastewater for irrigated agriculture and 

aquaculture. In Hanoi alone, an estimated 658,000 

farmers use wastewater to irrigate 108,178 ac (43,778 

ha) of land (Raschid-Sally and Jayakody, 2008).

Thanh Tri is a peri-urban district located in the south of 

Hanoi, downstream of the To Lich River, one of the 

main streams contaminated with wastewater from 

urban areas. Irrigation systems designed to uptake 

water from the To Lich River have been in use in some 

communes of the district water since the 1960s and 

are used to irrigate hundreds of hectares of agricultural 

land. 

In recent years, increased contamination from urban 

wastewater and industrial effluents has created 

problems for the traditional practice of wastewater 

reuse: loss of agriculture and aquaculture production 

affect the health of farmers and consumers. Thanh Liet 

commune in this district has designed a decentralized 

wastewater management system (DWMS) to 

accommodate wastewater reuse.

Capacity and Type of Reuse 

Application 

To combat the negative impact of wastewater effluent 

on crops, productivity, public health and the increase 

of unusable land, the Local Agriculture Cooperative 

(LAC), in agreement with local farmers, decided to 

transfer large areas of low productivity agricultural land 

to fishponds by gathering farmers’ fields and leasing 

them to fish raising men. In other words, the 

intervention does not seek to change the quality of the 

water itself, but instead change the type of reuse 

application to aquaculture, which is a safer use of the 

contaminated water.

The fishpond areas in Thanh Liet were originally used 

as a low land paddy for rice. Rice is less tolerant to 

contaminated water, so they shifted to other aquatic 

vegetables and fish ponds, which also have higher 

market values. Aquatic vegetables and fish production 

can generate 120 million Vietnamese dong (VND) per 

ha per year and 150 million VND/ha-yr ($5,760/ha-yr 

and $7,200/ha-yr), respectively which is three times 

higher than rice production. The total land area 

dedicated to aquaculture in Thanh Liet has increased 

over the last 10 years from about 25 to 85 hectares 

(60 to 210 acres) in 2011. More constructors are 

interested in this area since they could get substantial 

benefit from wastewater fed fishponds.

Institutional/Cultural Considerations 

Thanh Liet commune area has a population of 241,000 

people (2010) and is not yet covered by the service 

from Hanoi Sanitation and Drainage Company 

(SADCO). Therefore, the management of local 

sewerage and drainage system belongs to the 

commune’s People’s Committee (PC), who delegates 

the task to the LAC of the commune.

There is a policy for providing water for irrigation free 

of charge, creating a financial barrier for the LAC to 

invest in improving irrigation water quality and 

involving local farmers to the operations and 

maintenance (O&M) activities of the system.

Water Quality Standards and 

Treatment Technology 

There are no official regulations for wastewater use in 

Vietnam, except for microbiological quality standards 

specifying a maximum total coliform count for effluent 

discharge to surface water.

Project Funding and Management 

Practices 

For the construction of drainage canals and sewers 

along the roads of the commune, funding is mobilized 

from the city’s budget, via the District PC. In some 

cases, local farmers contribute, especially for their 

household connection to the drainage lines. Under the 

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

management of the local PC, the Thanh Liet LAC is 

assigned the function to operate water supply, 

sewage, drainage and irrigation systems. They are 

also providing other agricultural services for farmers 

such as supply of fertilizers, seeding crops and fish 

fingerlings. 

Institutional decentralization has created a strict 

separation of institutions at upper levels of 

management, causing difficulties for the LAC to 

integrate irrigation, drainage and sewage management 

at the local level. For instance, all of the wastewater

collected by the centralized wastewater system in 

Hanoi is discharged to the upper level of the canals. 

The LAC is unable to collect the wastewater discharge 

fee to cover the cost of treatment; therefore the water 

from these canals is diverted to the local irrigation 

system without proper treatment. 

Locations of fishponds are usually along the open 

drainage canals. One reason is the availability of 

leased land; since the soil is contaminated with 

wastewater and not suitable for growing crops, another 

reason is that fishermen could actively exploit the 

wastewater and do not solely depend on the LAC’s 

pumping services. Meanwhile, the cropping land is 

about 250 ac (100 ha) of which only 25 ac (10.5 ha) is 

used for cultivating rice and the rest is for aquatic 

vegetables. These fields are located further from 

drainage canals to reduce the impact of wastewater 

since the quality of the wastewater is improved in 

terms of nutrients, pathogens, and heavy metal 

concentration after partial treatment in ponds with the 

presence of aquatic plant cultivation and long 

channels.

Farmers and fishermen experience the negative 

impacts from wastewater such as skin and worm 

diseases. They have carried out different measures to 

reduce perceived impacts. Fishermen are more 

proactive; they combine wastewater and groundwater 

to dilute the wastewater, and in addition, wastewater 

pumps provide more oxygen to boost wastewater 

treatment process through biochemical oxygen 

demand breakdown in the ponds. Farmers and 

fishermen wear protective clothes while working to 

reduce the exposure level to wastewater.

Moreover, the farmers and fishermen are encouraged 

to participate in the agricultural extension training 

program organized by the LAC and the extension 

division of the district. The content of these training 

programs include the safe practice of wastewater 

reuse. Most of the crops and all fish products are 

required to be cooked before eating. 

Figure 1

Chemical Oxygen Demand (KMnO4) measured along 

the drainage channel in March 2011

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Appendix E | International Case Studies

2012 Guidelines for Water Reuse

Successes and Lessons Learned

Through a combination of various activities, e.g., 

conjunctive use of wastewater and groundwater, 

protective gear, improving hygienic condition, and 

raising awareness among producers and consumers, 

the impact of wastewater reuse has been minimized to 

a certain level. The practice of wastewater reuse in 

Thanh Liet behaves as spot market with complex and 

unpredictable long-term outcomes. 

Despite the numerous challenges, the DWMS of 

Thanh Tri could provide a concrete framework to build 

up an integrated system of wastewater reuse for 

irrigation at a local level where decentralized provision 

allows wastewater reuse to maximize resource 

recovery, i.e., where wastewater is collected and 

treated to the acceptable level for agriculture and 

aquaculture use in the area. 

Finally, further studies on the measurements taken out 

by the Thanh Liet people and reinforced with scientific 

base are needed to support the management of LAC 

by providing information to set up guidelines, 

standards, and regulations of the reuse of wastewater 

for application in other areas of the country. 

References

Lan Huong Nguyen, Yamaji Eiji. 2011. Integrating Urban 

Wastewater Management and Wastewater Irrigated 

Agriculture - A case study on farmers’ participation in Hanoi. 

Graduate School of Frontier Sciences, the University of 

Tokyo, Japan (Master’s thesis).

Viet-Anh Nguyen, Hanh T.H. Tran, Thanh T.M. Vu, 

Parkinson J., Barriero W. 2004. Decentralized wastewater 

management – A Hanoi case study. 30th WEDC International 

Conference, Vientiane, Lao PDR.

Raschid-Sally, L.; and Jayakody, P. 2008. Drivers and 

Characteristics of Wastewater Agriculture in Developing 

Countries: Results from a Global Assessment. IWMI RR 

127. 

Figure 2

Farmer working in the field in protective clothing 

(Photo credit: Lan Huong Nguyen)

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2012 Guidelines for Water Reuse F-1 

Appendix F 

Case Studies in 2004 Guidelines for Water Reuse

Section in 

2004 

Guidelines U.S. Case Study Title City State 

2.7.1 Water Reuse at Reedy Creek Improvement District Orlando FL

2.7.2 Estimating Potable Water Conserved in Altamonte Springs due to 

Reuse Altamonte Springs FL

2.7.3 How Using Potable Supplies to Supplement Reclaimed Water Flows 

can Increase Conservation Hillsborough County FL

2.7.4 Water Reclamation and Reuse Offer an Integrated Approach to 

Wastewater Treatment and Water Resources Issues in Phoenix Phoenix AZ 

2.7.5 Small and Growing Community: Yelm, Washington Yelm WA

2.7.6 Landscape Uses of Reclaimed Water with Elevated Salinity El Paso TX

2.7.7 Use of Reclaimed Water in a Fabric Dyeing Industry Santa Fe Springs CA

2.7.8 Survey of Power Plants Using Reclaimed Water for Cooling Water Multiple US

2.7.9 Agricultural Reuse in Tallahassee, Florida Tallahassee FL

2.7.10 Spray Irrigation at Durbin Creek WWTP Western Carolina Regional 

Sewer Authority Fountain Inn SC 

2.7.11 Agricultural Irrigation of Vegetable Crops: Monterey, CA Monterey CA

2.7.12 Water Conserv II: City of Orlando and Orange County, FL Orange County FL

2.7.13 The Creation of a Wetlands Park: Petaluma, CA Petaluma CA

2.7.14 Geysers Recharge Project: Santa Rosa, CA Santa Rosa CA

2.7.15 Advanced Wastewater Reclamation in California Orange County CA

2.7.16 An Investigation of Soil Aquifer Treatment for Sustainable Water 6 sites AZ/CA

2.7.17 The City of West Palm Beach, Florida Wetlands-Based Water 

Reclamation Project West Palm Beach FL

2.7.18 Types of Reuse Applications in Florida Statewide FL

2.7.19 Regionalizing Reclaimed Water in the Tampa Bay Area Tampa Bay FL

3.8.1 Code of Good Practices for Water Reuse Statewide FL

3.8.2 Examples of Potable Water Separation Standards from the State of 

Washington Statewide WA

3.8.3 An Example of using Risk Assessment to Establish Reclaimed Water 

Quality Study US

5.7.1 Statutory Mandate to Utilize Reclaimed Water: California Statewide CA

5.7.2 Administrative Order to Evaluate Feasibility of Water Reclamation: 

Fallbrook Sanitary District, Fallbrook, CA Fallbrook CA

5.7.3 Reclaimed Water User Agreements Instead of Ordinance: Central 

Florida Orlando FL

5.7.4 Interagency Agreement Required for Water Reuse: Monterey County 

Water Recycling Project, Monterey, CA Monterey CA

5.7.5 Public/Private Partnership to Expand Reuse Program: The City Of 

Orlando, Orange County and The Private Sector Orlando FL

5.7.6 Inspection of Reclaimed Water Connections Protect Potable Water 

Supply: Pinellas County Utilities, Florida Pinellas County FL

5.7.7 Oneida Indian Nation/Municipal/State Coordination Leads to Effluent 

Reuse: Oneida Nation, New York Oneida NY

5.7.8 Implementing Massachusetts’ First Golf Course Irrigation System 

Utilizing Reclaimed Water: Yarmouth, MA Yarmouth MA
Appendix F | Case Studies in 2004 Guidelines for Water Reuse

F-2 2012 Guidelines for Water Reuse

Section in 

2004 

Guidelines U.S. Case Study Title City State 

6.7.1 Unique Funding Aspects of the Town of Longboat Key Reclaimed 

Water System Longboat Key FL

6.7.2 Financial Assistance in San Diego County, California San Diego CA

6.7.3 Grant Funding Through the Southwest Florida Water Management 

District SW Florida FL

6.7.4 Use of Reclaimed Water to Augment Potable Supplies: An Economic 

Perspective (California) LA/Orange Co. CA

6.7.5 Impact Fee Development Considerations for Reclaimed Water 

Projects: Hillsborough County, FL Hillsborough County FL

6.7.6 How Much Does it Cost and Who Pays: A Look at Florida’s Reclaimed 

Water Rates Statewide FL

6.7.7 Rate Setting for Industrial Reuse in San Marcos, TX San Marcos TX

7.5.1 Accepting Produce Grown with Reclaimed Water: Monterey, California Monterey CA

7.5.2 Water Independence in Cape Coral – An Implementation Update in 

2003 Cape Coral FL

7.5.3.1 Learning Important Lessons-San Diego, California San Diego CA

7.5.3.2 Public Outreach May not be Enough: Tampa, FL Tampa FL

7.5.4 Pinellas County, Florida Adds Reclaimed Water to Three R’s of 

Education Pinellas County FL

7.5.5 Yelm, Washington, A Reclaimed Water Success Story Yelm WA

7.5.6 Gwinnett County, Georgia – Master Plan Update Authored by Public Gwinnett County GA

7.5.7 AWWA Golf Course Reclaimed Water Market Assessment National U.S. 

Section in 

2004 

Guidelines International Case Study by Country

8.5.1 Argentina

8.5.2 Australia 

8.5.2.1 Aurora, Australia

8.5.2.2 Mawson Lakes, Australia

8.5.2.3 Virginia Project, South Australia

8.5.3 Belgium

8.5.4 Brazil 

8.5.4.1 Sao Paulo, Brazil

8.5.4.2 Sao Paulo International Airport, Brazil

8.5.5 Chile

8.5.6 China

8.5.7 Cyprus

8.5.8 Egypt

8.5.9 France

8.5.10 Greece

8.5.11 India

8.5.12.1 Hyderabad, India

8.5.12 Iran 

8.5.13 Israel

8.5.14 Italy

8.5.15 Japan

8.5.16 Jordan
Appendix F | Case Studies in 2004 Guidelines for Water Reuse

2012 Guidelines for Water Reuse F-3 

Section in 

2004 

Guidelines International Case Study by Country

8.5.17 Kuwait

8.5.18 Mexico

8.5.19 Morocco

8.5.20.1 Drarga, Morocco

8.5.20 Namibia

8.5.21 Oman

8.5.22 Pakistan

8.5.23 Palestinian National Authority

8.5.24 Peru 

8.5.25 Saudi Arabia

8.5.26 Singapore

8.5.27 South Africa

8.5.28 Spain

8.5.28.1 Costa Brava, Spain

8.5.28.2 Portbou, Spain

8.5.28.3 Aiguamolls de l’Emporda Natural Preserve, Spain

8.5.28.4 The City of Victoria, Spain

8.5.29 Sweden

8.5.30 Syria 

8.5.31 Tunisia

8.5.32 United Arab Emirates

8.5.33 United Kingdom

8.5.34 Yemen

8.5.35 Zimbabwe
Appendix F | Case Studies in 2004 Guidelines for Water Reuse

F-4 2012 Guidelines for Water Reuse

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2012 Guidelines for Water Reuse G-1 

APPENDIX G 

Abbreviations

Abbreviations for Names of States

Full Name Text Abbreviation Case Study Abbreviation

Alabama Ala. AL

Alaska Alaska AK

Arizona Ariz. AZ

Arkansas Ark. AR

California Calif. CA

Colorado Colo. CO

Connecticut Conn. CT

Delaware Del. DE

District of Columbia D.C. DC

Florida Fla. FL

Georgia Ga. GA

Hawaii Hawaii HI

Idaho Idaho ID

Illinois Ill. IL

Indiana Ind. IN

Iowa Iowa IA

Kansas Kan. KS

Kentucky Ky. KY

Louisiana La. LA

Maine Maine ME

Maryland Md. MD

Massachusetts Mass. MA

Michigan Mich. MI

Minnesota Minn. MN

Mississippi Miss. MS

Missouri Mo. MO

Montana Mont. MT

Nebraska Neb. NE

Nevada Nev. NV

New Hampshire N.H. NH

New Jersey N.J. NJ

New Mexico N.M. NM

New York N.Y. NY

North Carolina N.C. NC

North Dakota N.D. ND

Ohio Ohio OH

Oklahoma Okla. OK

Oregon Ore. OR

Pennsylvania Pa. PA

Rhode Island R.I. RI

South Carolina S.C. SC

South Dakota S.D. SD

Tennessee Tenn. TN

Texas Texas TX

Utah Utah UT

Vermont Vt. VT

Virginia Va. VA

Washington Wash. WA

West Virginia W. Va. WV

Wisconsin Wis. WI

Wyoming Wyo. WY
Appendix G | Abbreviations 

G-2 

Abbreviations for Units of Measure

Abbreviation Unit Abbreviation Unit

ac Acre m Meter

ac-ft Acre-foot m/s Meters per second

ac-ft/yr Acre-foot per year μg Microgram (10-6 g)

bbl/yr Barrels per year μg/L Micrograms per liter

BTU British thermal unit MCM Million cubic meters

cfu Colony forming units MCM/yr Million cubic meters per year

cm Centimeter mgd Million (106) gallons per day

m Cubic meter 3 μm Micrometer (10-6 m)

m3/d Cubic meters per day mi Mile

d Day mph Miles per hour

°C Degrees Celsius mg Milligram (10-3 g)

°F Degrees Fahrenheit mg/L Milligrams per liter

ft Foot (feet) mL Milliliter (10-3 l)

gallon Gallon mm Millimeter (10-3 m)

GJ Gigajoules meq/L Milliequivalent per liter

gpd Gallons per day MAFY Million acre feet per year

gpcd Gallons per capita per day min Minute

gpm Gallons per minute MPN Most probable number

g Gram nm Nanometer (10-9 m)

ha Hectare NTU Nephelometric turbidity units

hp Horsepower ppt Parts per trillion

hr Hour Pa Pascal

ccf Hundred cubic feet pfu Plaque forming unit

in Inch lb Pound

J Joules lb/ac Pounds per acre

kg Kilogram (103 g) psi Pounds per square inch

kg/ha Kilogram per hectare s Second

km Kilometer (103 m) ft Square foot 2

kPa Kilopascal (103 Pa) in Square inch 2

kW Kilowatt (103 W) km Square kilometers 2

kWh Kilowatt hour m Square meter 2

L Liter mi Square mile 2

Lpcd Liters per capita per day TWh/yr TWh/yr

L/s Liters per second W Watt

MW Megawatt (106 W) yr Year

MWhr Megawatt hours
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