EPA/600/R-12/618 | September 2012
United States
Environmental Protection
Agency
2012
I Guidelines for Water Reuse
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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.
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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.
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Notice
This document was produced by COM Smith Inc. (COM 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
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Foreword
For decades, communities have been reusing valuable reclaimed water to recharge groundwater aquifers, irrigate
landscapes and agricultural fields, provide critical stream flows, and provide industries and facilities with an
alternative to potable water for a range of uses. While water reuse is not new, population increases and land use
changes, combined with changes in the intensity and dynamics of local climatic weather patterns, have
exacerbated water supply challenges in many areas of the world. Furthermore, treated wastewater is increasingly
being seen as a resource rather than simply 'waste.' In this context, water reclamation and reuse have taken on
increased importance in the water supply of communities in the United States and around the world in order to
achieve efficient resource use, ensure protection of environmental and human health, and improve water
management. Strict effluent discharge limits have spurred effective and reliable improvements in treatment
technologies. Along with a growing interest in more sustainable water supplies, these improvements have led an
increasing number of communities to use reclaimed water as an alternative source to conventional water supplies
for a range of applications. In some areas of the United States, water reuse and dual water systems for
distribution of reclaimed water for nonpotable uses have become fully integrated into local water supplies.
Alternative and efficient water supply options, including reclaimed water, are necessary components of holistic
and sustainable water management.
As a collaborative effort between EPA and USAID, this document's primary purpose is to facilitate further
development of water reuse by serving as an authoritative reference on water reuse practices. In the United
States, water reuse regulation is primarily under the jurisdiction of states, tribal nations, and territories. This
document includes an updated overview of regulations or guidelines addressing water reuse that are promulgated
by these authorities. Regulations vary from state to state, and some states have yet to develop water reuse
guidelines or regulations. This document meets a critical need: it informs and supplements state regulations and
guidelines by providing technical information and outlining key implementation considerations. It also presents
frameworks should states, tribes, or other authorities decide to develop new regulations or guidelines.
This document updates and builds on the 2004 Guidelines for Water Reuse by incorporating information on water
reuse that has been developed since the 2004 document was issued. This document includes updated discussion
of regional variations of water reuse in the United States, advances in wastewater treatment technologies relevant
to reuse, best practices for involving communities in planning projects, international water reuse practices, and
factors that will allow expansion of safe and sustainable water reuse throughout the world. The 2012 guidelines
also provide more than 100 new case studies from around the world that highlight how reuse applications can and
do work in the real world.
Over 300 reuse experts, practitioners, and regulators contributed text, technical reviews, regulatory information,
and case studies. This breadth of experience provides a broad and blended perspective of the scientific,
technical, and programmatic principles for implementing decisions about water reuse in a safe and sustainable
manner.
Nancy Stoner
Acting Assistant Administrator
Office of Water
U.S. EPA
Lek Kadeli
Acting Assistant Administrator
Office of Research & Development
U.S. EPA
Eric Postel
Assistant Administrator
Bureau for Economic Growth, Education & Environment
USAID
2012 Guidelines for Water Reuse
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Updating the Guidelines
The Guidelines for Water Reuse debuted in 1980 and was updated in 1992 and 2004. EPA contracted with COM
Smith through a CRADA to update the EPA guidelines for this 2012 release. Building on the work of previous
versions, the COM 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. Non-
governmental 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
iv 2012 Guidelines for Water Reuse
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• 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 in-
person 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.
2012 Guidelines for Water Reuse
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Table of Contents
Chapter 1 Introduction 1-1
1.1 Objectives of the Guidelines 1-1
1.2 Overview of the Guidelines 1-2
1.3 Guidelines Terminology 1-2
1.4 Motivation for Reuse 1-5
1.4.1 Urbanization and Water Scarcity 1-5
1.4.2 Water-Energy Nexus 1-5
1.4.3 Environmental Protection 1-6
1.5 "Fit for Purpose" 1-7
1.6 References 1-8
Chapter 2 Planning and Management Considerations 2-1
2.1 Integrated Water Management 2-1
2.2 Planning Municipal Reclaimed Water Systems 2-3
2.2.1 Identifying Users and Types of Reuse Demands 2-4
2.2.2 Land Use and Local Reuse Policy 2-4
2.2.3 Distribution System Considerations 2-6
2.2.3.1 Distribution System Pumping and Piping 2-7
2.2.3.2 Reclaimed Water Appurtenances 2-8
2.2.3.3 On-Site Construction Considerations 2-9
2.2.4 Institutional Considerations 2-10
2.3 Managing Reclaimed Water Supplies 2-11
2.3.1 Operational Storage 2-12
2.3.2 Surface Water Storage and Augmentation 2-13
2.3.3 Managed Aquifer Recharge 2-14
2.3.3.1 Water Quality Considerations 2-15
2.3.3.2 Surface Spreading 2-16
2.3.3.3 Injection Wells 2-17
2.3.3.4 Recovery of Reclaimed Water through ASR 2-20
2.3.3.5 Supplementing Reclaimed Water Supplies 2-22
2.3.4 Operating a Reclaimed Water System 2-23
2.3.4.1 Quality Control in Production of Reclaimed Water 2-23
2.3.4.2 Distribution System Safeguards for
Public Health Protection in Nonpotable Reuse 2-23
2.3.4.3 Preventing Improper Use and Backflow 2-25
2.3.4.4 Maintenance 2-25
2.3.4.5 Quality Assurance: Monitoring Programs 2-26
2.3.4.6 Response to Failures 2-27
2.3.5 Lessons Learned from Large, Medium, and Small Systems 2-28
2.4 Water Supply Conservation and Alternative Water Resources 2-31
2.4.1 Water Conservation 2-31
2.4.2 Alternative Water Resources 2-32
2.4.2.1 Individual On-site Reuse Systems and Graywater Reuse 2-32
2.4.2.2 LEED-Driven On-site Treatment 2-35
2.4.2.3 Stormwater Harvesting and Use 2-37
2.5 Environmental Considerations 2-37
vi 2012 Guidelines for Water Reuse
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2.5.1 Land Use Impacts 2-38
2.5.2 Water Quantity Impacts 2-38
2.5.3 Water Quality Impacts 2-39
2.6 References 2-40
Chapter 3 Types of Reuse Applications 3-1
3.1 Urban Reuse 3-2
3.1.1 Golf Courses and Recreational Field Irrigation 3-2
3.2 Agricultural Reuse 3-4
3.2.1 Agricultural Reuse Standards 3-6
3.2.2 Agricultural Reuse Water Quality 3-6
3.2.2.1 Salinity and Chlorine Residual 3-8
3.2.2.2 Trace Elements and Nutrients 3-8
3.2.2.3 Operational Considerations for Agricultural Reuse 3-10
3.2.3 Irrigation of Food Crops 3-10
3.2.4 Irrigation of Processed Food Crops and Non-Food Crops 3-11
3.2.5 Reclaimed Water for Livestock Watering 3-13
3.3 Impoundments 3-13
3.3.1 Recreational and Landscape Impoundments 3-14
3.3.2 Snowmaking 3-14
3.4 Environmental Reuse 3-16
3.4.1 Wetlands 3-16
3.4.1.1 Wildlife Habitat and Fisheries 3-18
3.3.1.2 Flood Attenuation and Hydrologic Balance 3-18
3.3.1.3 Recreation and Educational Benefits 3-18
3.4.2 River or Stream Flow Augmentation 3-19
3.4.3 Ecological Impacts of Environmental Reuse 3-19
3.5 Industrial Reuse 3-20
3.5.1 Cooling Towers 3-20
3.5.2 Boiler Water Makeup 3-22
3.5.3 Produced Water from Oil and Natural Gas Production 3-23
3.5.4 High-Technology Water Reuse 3-24
3.5.5 Prepared Food Manufacturing 3-24
3.6 Groundwater Recharge - Nonpotable Reuse 3-26
3.7 Potable Reuse 3-26
3.7.1 Planned Indirect Potable Reuse (IPR) 3-28
3.7.2 Direct Potable Reuse (DPR) 3-30
3.7.2.1 Planning for DPR 3-30
3.7.2.2 Future Research Needs 3-32
3.8 References 3-33
Chapter 4 State Regulatory Programs for Water Reuse 4-1
4.1 Reuse Program Framework 4-1
4.2 Regulatory Framework 4-1
4.3 Relationship of State Regulatory Programs for Water Reuse to Other
Regulatory Programs 4-1
4.3.1 Water Rights 4-4
4.3.2 Water Supply and Use Regulations 4-5
4.3.3 Wastewater Regulations and Related Environmental Regulations 4-5
2012 Guidelines for Water Reuse vii
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4.3.4 Drinking Water Source Protection 4-6
4.3.5 Land Use 4-6
4.4 Suggested Regulatory Guidelines for Water Reuse Categories 4-6
4.4.1 Water Reuse Categories 4-7
4.4.2 Suggested Regulatory Guidelines 4-7
4.4.3 Rationale for Suggested Regulatory Guidelines 4-7
4.4.3.1 Combining Treatment Process Requirements with
Water Quality Limits 4-12
4.4.3.2 Water Quality Requirements for Disinfection 4-12
4.4.3.3 Indicators of Disinfection 4-13
4.4.3.4 Water Quality Requirements for Suspended and Paniculate 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 ofWater 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
viii 2012 Guidelines for Water Reuse
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5.2.2.3 Water Use by Sector 5-13
5.2.2.4. States' Regulatory Context 5-13
5.2.2.5 Context and Drivers of Water Reuse 5-14
5.2.3 Southeast 5-15
5.2.3.1 Population and Land Use 5-15
5.2.3.2 Precipitation and Climate 5-16
5.2.3.3 Water Use by Sector 5-16
5.2.3.4. States' Regulatory Context 5-18
5.2.3.5 Context and Drivers of Water Reuse 5-19
5.2.4 Midwest and Great Lakes 5-23
5.2.4.1 Population and Land Use 5-23
5.2.4.2 Precipitation and Climate 5-24
5.2.4.3 Water Use by Sector 5-24
5.2.4.4. States' Regulatory Context 5-25
5.2.4.5 Context and Drivers of Water Reuse 5-26
5.2.5 South Central 5-29
5.2.5.1 Population and Land Use 5-29
5.2.5.2 Precipitation and Climate 5-29
5.2.5.3 Water Use by Sector 5-30
5.2.5.4. States' Regulatory Context 5-30
5.2.5.5 Context and Drivers of Water Reuse 5-31
5.2.6 Mountains and Plains 5-35
5.2.6.1 Population and Land Use 5-35
5.2.6.2 Precipitation 5-35
5.2.6.3 Water Use by Sector 5-35
5.2.6.4. States' Regulatory Context 5-36
5.2.6.5 Context and Drivers of Water Reuse 5-36
5.2.7 Pacific Southwest 5-37
5.2.7.1 Population and Land Use 5-37
5.2.7.2 Precipitation and Climate 5-38
5.2.7.3 Water Use by Sector 5-39
5.2.7.4. States' Regulatory Context 5-39
5.2.7.5 Context and Drivers of Water Reuse 5-41
5.2.8 Pacific Northwest 5-44
5.2.8.1 Population and Land Use 5-45
5.2.8.2 Precipitation and Climate 5-45
5.2.8.3 Water Use by Sector 5-46
5.2.8.4. States' Regulatory Context 5-46
5.2.8.5 Context and Drivers of Water Reuse 5-47
5.3 References 5-48
Chapter 6 Treatment Technologies for Protecting Public and Environmental Health...6-1
6.1 Public Health Considerations 6-2
6.1.1 What is the Intended Use of the Reclaimed Water? 6-2
6.1.2 What Constituents are Present in a Wastewater Source, and
What Level of Treatment is Applicable for Reducing Constituents to
Levels that Achieve the Desired Reclaimed Water Quality? 6-3
6.1.3 Which Sampling/Monitoring Protocols Are Required to Ensure that
Water Quality Objectives Are Being Met? 6-3
6.2 Wastewater Constituents and Assessing Their Risks 6-4
2012 Guidelines for Water Reuse ix
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6.2.1 Microorganisms in Wastewater 6-4
6.2.1.1 Protozoa and Helminths 6-6
6.2.1.2 Bacteria 6-6
6.2.1.3 Viruses 6-7
6.2.1.4 Aerosols 6-7
6.2.1.5 Indicator Organisms 6-7
6.2.1.6 Removal of Microorganisms 6-8
6.2.1.7 Risk Assessment of Microbial Contaminants 6-9
6.2.2 Chemicals in Wastewater 6-10
6.2.2.1 Inorganic Chemicals 6-10
6.2.2.2 Organics 6-11
6.2.2.3 Trace Chemical Constituents 6-12
6.3 Regulatory Approaches to Establishing Treatment Goals for Reclaimed Water 6-17
6.3.1 Microbial Inactivation 6-18
6.3.2 Constituents of Emerging Concern 6-19
6.3.2.1 Example of California's Regulatory Approach to CECs 6-20
6.3.2.2 Example of Australia's Regulatory Approach to Pharmaceuticals 6-21
6.4 Wastewater Treatment for Reuse 6-21
6.4.1 Source Control 6-22
6.4.2 Filtration 6-23
6.4.2.1 Depth Filtration 6-24
6.4.2.2 Surface Filtration 6-24
6.4.2.3 Membrane Filtration 6-24
6.4.2.4 Biofiltration 6-25
6.4.3 Disinfection 6-26
6.4.3.1 Chlorination 6-27
6.4.3.2 Ultraviolet Disinfection 6-28
6.4.3.3 Ozone 6-30
6.4.3.4 Pasteurization 6-31
6.4.3.5 Ferrate 6-32
6.4.4 Advanced Oxidation 6-32
6.4.5 Natural Systems 6-34
6.4.5.1 Treatment Mechanisms in Natural Systems 6-34
6.4.5.2 Wetlands 6-36
6.4.5.3 Soil Aquifer Treatment Systems 6-37
6.4.6 Monitoring for Treatment Performance 6-37
6.4.7 Energy Considerations in Reclaimed Water Treatment 6-38
6.5 References 6-39
Chapter 7 Funding Water Reuse Systems 7-1
7.1 Integrating Reclaimed Water into a Water Resource Portfolio 7-1
7.2 Internal and Debt Funding Alternatives 7-2
7.2.1 State and Federal Financial Assistance 7-2
7.2.1.1 Federal Funding Sources 7-3
7.2.1.2 State, Regional, and Local Grant and Loan Support 7-4
7.3 Phasing and Participation Incentives 7-5
7.4 Sample Rate and Fee Structures 7-6
7.4.1 Service Fees 7-6
7.4.2 Special Assessments 7-8
7.4.3 Impact Fees 7-8
2012 Guidelines for Water Reuse
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7.4.4 Fixed Monthly Fee 7-8
7.4.5 Volumetric Rates 7-8
7.5 Developing Rates 7-8
7.5.1 Market Rates Driven by Potable Water 7-10
7.5.2 Service Agreements Based on Take or Pay Charges 7-11
7.5.3 Reuse Systems for New Development 7-12
7.5.4 Connection Fees for Wastewater Treatment versus Distribution 7-12
7.6 References 7-13
Chapter 8 Public Outreach, Participation, and Consultation 8-1
8.1 Defining Public Involvement 8-1
8.1.1 Public Opinion Shift: Reuse as an Option in the Water Management Toolbox 8-1
8.1.2 Framing the Benefits 8-2
8.2 Why Public Participation is Critical 8-3
8.2.1 Project Success 8-3
8.2.2 The Importance of an Informed Constituency 8-3
8.2.3 Building Trust 8-3
8.3 Identifying the "Public" 8-4
8.4 Steps to Successful Public Participation 8-4
8.4.1 Situational Analysis 8-5
8.4.1.1 Environmental Justice 8-6
8.4.2 Levels of Involvement 8-7
8.4.3 Communication Plan 8-7
8.4.3.1 The Role of Information in Changing Opinion 8-7
8.4.3.2 Words Count 8-8
8.4.3.3 Slogans and Branding 8-11
8.4.3.4 Reclaimed Water Signage 8-11
8.4.4 Public Understanding 8-12
8.4.4.1 Perception of Risk 8-12
8.4.4.2 Trusted Information Sources 8-12
8.4.5 Community Leaders 8-13
8.4.6 Independent Experts 8-13
8.4.6.1 Advisory Groups 8-13
8.4.6.2 Independent Advisory Panels 8-14
8.4.6.3 Independent Monitoring and Certification 8-14
8.4.7 Media Outreach 8-15
8.4.7.1 New Media Outreach Methods - Social Networking 8-15
8.4.8 Involving Employees 8-16
8.4.9 Direct Stakeholder Engagement 8-16
8.4.9.1 Dialogue with Stakeholders 8-16
8.4.9.2 Addressing Opposition 8-16
8.5 Variations in Public Outreach 8-17
8.6 References 8-18
Chapter 9 Global Experiences in Water Reuse 9-1
9.1 Introduction 9-1
9.1.1 Defining the Resources Context 9-1
9.1.2 Planned Water Reuse and Wastewater Use 9-1
9.1.3 International Case Studies 9-2
2012 Guidelines for Water Reuse xi
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9.2 Overview of Global Water Reuse 9-6
9.2.1 Types of Water Reuse 9-6
9.2.1.1 Agricultural Applications 9-6
9.2.1.2 Urban and Industrial Applications 9-6
9.2.1.3 Aquifer Recharge 9-7
9.2.2 Magnitude of Global Water Reuse 9-7
9.3 Opportunities and Challenges for Expanding the Scale of Global Water Reuse 9-8
9.3.1 Global Drivers 9-9
9.3.2 Regional Variation in Water Reuse 9-10
9.3.3 Global Barriers to Expanding Planned Reuse 9-11
9.3.3.1 Institutional Barriers 9-11
9.3.3.2 Public Perception/Educational Barriers 9-12
9.3.3.3 Economic Barriers 9-12
9.3.3.4 Organizational Barriers 9-12
9.3.4 Benefits of Expanding the Scale of Water Reuse 9-13
9.4 Improving Safe and Sustainable Water Reuse for Optimal Benefits 9-13
9.4.1 Reducing Risks of Unplanned Reuse: The WHO Approach 9-13
9.4.2 Expanding and Optimizing Planned Water Reuse 9-16
9.5 Factors Enabling Successful Implementation of Safe and Sustainable
Water Reuse 9-20
9.6 Global Lessons Learned About Water Reuse 9-21
9.7 References 9-22
Appendix A Funding for Water Reuse Research A-1
Appendix B Inventory of Recent Water Reuse Research Projects and Reports B-1
Appendix C Websites of U.S. State Regulations and Guidance on Water Reuse C-1
Appendix D U.S. Case Studies D-1
Appendix E International Case Studies and International Regulations E-1
Appendix F List of Case Studies in 2004 Guidelines for Water Reuse F-1
Appendix G Abbreviations G-1
xii 2012 Guidelines for Water Reuse
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List of Tables
Chapter 1
Table 1-1 Organization of 2012 Guidelines for Water Reuse 1-3
Table 1-2 Categories of water reuse applications 1-4
Chapter 2
Table 2-1 Common institutional arrangements for water reuse 2-10
Table 2-2 Comparison of vadose zone and direct injection recharge wells 2-18
Table 2-3 Operational status and source water treatment for reclaimed water ASR
projects 2-22
Table 2-4 Quality monitoring requirements in Texas 2-26
Table 2-5 Summary of NSF Standard 350 Effluent Criteria for individual classifications ....2-34
Table 2-6 Summary of ANSI/NSF Standard 350-1 for subsurface discharges 2-34
Chapter 3
Table 3-1 Distribution of reclaimed water in California and Florida 3-2
Table 3-2 Interpretation of reclaimed water quality 3-3
Table 3-3 Nationwide reuse summaries of reclaimed water use in agricultural irrigation 3-5
Table 3-4 Guidelines for interpretation of water quality for irrigation 3-7
Table 3-5 Recommended water quality criteria for irrigation 3-9
Table 3-6 Examples of global water quality standards for non-food crop irrigation 3-13
Table 3-7 Guidelines for concentrations of substances in livestock drinking water 3-13
Table 3-8 Recommended boiler water limits 3-22
Table 3-9 Overview of selected planned indirect and direct potable reuse installations
worldwide (not intended to be a complete survey) 3-28
Chapter 4
Table 4-1 Key elements of a water reuse program 4-2
Table 4-2 Fundamental components of a water reuse regulatory framework for states 4-3
Table 4-3 Water reuse categories and number of states with rules, regulations or
guidelines addressing these reuse categories 4-8
Table 4-4 Suggested guidelines for water reuse 4-9
Table 4-5 Summary of State and U.S. Territory reuse regulations and guidelines 4-18
Table 4-6 Abbreviations of terms for state reuse rules descriptions 4-23
Table 4-7 Urban reuse - unrestricted 4-26
Table 4-8 Urban reuse - restricted 4-27
Table 4-9 Agricultural reuse - food crops 4-28
Table 4-10 Agricultural reuse - non-food crops and processed food crops (where
permitted) 4-29
Table 4-11 Impoundments - unrestricted 4-30
Table 4-12 Impoundments - restricted 4-31
Table 4-13 Environmental reuse 4-32
Table 4-14 Industrial reuse 4-33
Table 4-15 Groundwater recharge - nonpotable reuse 4-34
Table 4-16 Indirect potable reuse (IPR) 4-35
2012 Guidelines for Water Reuse xiii
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Chapter 5
Table 5-1 Percent change in resident population in each region during the
periods 1990-2000, 2000-2010, and 1990-2010 5-7
Chapter 6
Table 6-1 Types of reuse appropriate for increasing levels of treatment 6-2
Table 6-2 Infectious agents potentially present in untreated (raw) wastewater 6-5
Table 6-3 Indicative log removals of indicator microorganisms and enteric
pathogens during various stages of wastewater treatment 6-9
Table 6-4 Categories of trace chemical constituents (natural and synthetic)
potentially detectable in reclaimed water and illustrative example chemicals 6-13
Table 6-5 Indicative percent removals of organic chemicals during various
stages of wastewater treatment 6-16
Table 6-6 Summary of filter type characteristics 6-25
Table 6-7 California and Florida disinfection treatment-based standards
for tertiary recycled water and high level disinfection 6-27
Table 6-8 Electrochemical oxidation potential (EOP) for several disinfectants 6-33
Chapter 7
Table 7-1 Comparison of reclaimed water rates 7-7
Table 7-2 Utility distribution of the reclaimed water rate as a percent of the
potable water rate for single-family homes in Florida 7-11
Chapter 8
Table 8-1 Focus group participant responses-most trusted sources 8-13
Chapter 9
Table 9-1 Global domestic wastewater generated and treated 9-7
Table 9-2 Projected reuse capacity in selected countries 9-8
Table 9-3 Percent of urban populations connected to piped sewer systems in
2003-2006 9-11
Table 9-4 Selected health-protection measures and associated pathogen reductions
for wastewater reuse in agriculture 9-15
Table 9-5 Challenges and solutions for reuse standards development and
implementation 9-17
xiv 2012 Guidelines for Water Reuse
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List of Figures
Chapter 1
Figure 1-1 The 2004 EPA Guidelines for Water Reuse has had global influence 1-1
Figure 1-2 Purple pipe is widely used for reclaimed water distribution systems 1-6
Figure 1-3 Treatment technologies are available to achieve any desired
level of water quality 1-7
Chapter 2
Figure 2-1 Traditional versus Integrated Water Management 2-1
Figure 2-2 36-inch CSC 301 purple mortar pipe, San Antonio Water System 2-7
Figure 2-3 Appropriate separation of potable, reclaimed water, and sanitary sewer pipes...2-8
Figure 2-4 Purple snap-on reclaimed water identification cap 2-9
Figure 2-5 Commonly used methods in managed aquifer recharge 2-15
Figure 2-6 Sample decision tree for selection of groundwater recharge method 2-15
Figure 2-7 Typical sign complying with FDEP signage requirements 2-24
Figure 2-8 Reclaimed water pumping station, San Antonio, Texas 2-25
Figure 2-9 Upper Occoquan schematic 2-29
Chapter 3
Figure 3-1 Reclaimed water use in the United States 3-1
Figure 3-2 Nationwide reuse summaries of reclaimed water use in agricultural irrigation ...3-5
Figure 3-3 Monterey County vegetable fields irrigated with disinfected tertiary recycled
water 3-12
Figure 3-4 Alfalfa irrigated with secondary effluent, Wadi Mousa (near Petra), Jordan 3-12
Figure 3-5 Large hyperbolic cooling towers 3-21
Figure 3-6 Estimates of produced water by state 3-23
Figure 3-7 Planned IPR scenarios and examples 3-29
Figure 3-8 Planned DPR and specific examples of implementation 3-31
Chapter 5
Figure 5-1 Freshwater use by category in the United States 5-1
Figure 5-2 Geographic display of United States reuse case studies categorized by
application 5-3
Figure 5-3 Percent change in population (2000-2010) and developed land
(1997-2007) in the Northeast Region, compared to the United States 5-9
Figure 5-4 Average monthly precipitation (1971-2000) for states in the Northeast Region...5-9
Figure 5-5 Freshwater use by sector for the Northeast region 5-9
Figure 5-6 Change in population (2000-2010) and developed land (1997-2007) in the
Mid-Atlantic region, compared to the United States 5-12
Figure 5-7 Average monthly precipitation in the Mid-Atlantic region 5-13
Figure 5-8 Freshwater use by sector for the Mid-Atlantic region 5-13
Figure 5-9 Change in population (2000-2010) and developed land (1997-2007) in the
Southeast region, compared to the United States 5-16
Figure 5-10 Average monthly precipitation in the Southeast region 5-16
Figure 5-11 Freshwater use by sector for the Southeast region 5-17
Figure 5-12 Water reuse in Florida by type 5-20
2012 Guidelines for Water Reuse xv
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Figure 5-13 Map of per capita reuse flow by county in Florida 5-21
Figure 5-14 Gary, 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
xvi 2012 Guidelines for Water Reuse
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Figure 8-5 CVWD encourages its wholesale customers to promote the
notification of reuse water benefits 8-12
Figure 8-6 A luncheon was held in King County, Wash, to present data on
reclaimed water used for irrigation, along with lunch featuring crops and
flowers from the reuse irrigation study 8-17
Chapter 9
Figure 9-1 Geographic display of international water reuse case studies
categorized by application 9-3
Figure 9-2 Global water reuse after advanced (tertiary) treatment: market
share by application 9-6
Figure 9-3 Countries with greatest irrigated areas using treated and untreated
wastewater 9-9
Figure 9-4Reducing the pathogenic health risks from unsafe use of diluted wastewater....9-16
Figure 9-5 Multi-barrier approach to safeguard public health where
wastewater treatment is limited 9-17
2012 Guidelines for Water Reuse xvii
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Dedication
Daniel James Deely
(1944-2012)
This document is dedicated to Daniel James Deely, for his tireless dedication to a decades-long collaboration
between EPA and USAID and to the Guidelines for Water Reuse. It is because of Dan's vision that this
collaboration came about and was sustained. Dan served more than 40 years with USAID working on
environmental and development projects worldwide. Dan was a walking reference for the history of the agency's
water programming. His wisdom, patience, strong dedication to the human development mission of USAID, and
expertise are dearly missed by his colleagues and his extended network of professional contacts.
xviii 2012 Guidelines for Water Reuse
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Acknowledgements
The Guidelines for Water Reuse was first published in 1980 and was updated in 1992 and 2004. Since then,
water reuse practices have continued to develop and evolve. This edition of the Guidelines offers new information
and greater detail about a wide range of reuse applications and introduces new concepts and treatment
technologies supporting water reuse operations. It includes an updated inventory of state reuse regulations and
expanded coverage of water reuse practices in countries outside of the United States. More than 300 reuse
experts contributed text and case studies to highlight how reuse applications can and do work in the real world.
The 2012 Guidelines for Water Reuse stands on the foundation of information generated by the substantial
research and development efforts and extensive demonstration projects on water reuse practices throughout the
world. Some of the most useful sources consulted in developing this update include conference proceedings,
reports, and journal articles published by a range of organizations, including: the WateReuse Association (WRA),
WateReuse Research Foundation (WRRF), Water Environment Federation (WEF), Water Environment Research
Foundation (WERF), and AWWA. The National Research Council's Water Reuse: Potential for Expanding the
Nation's Water Supply Through Reuse of Municipal Wastewater 2012 report was a timely and key contribution to
the information contained in this document. This study takes a comprehensive look at the potential for reclamation
and reuse of municipal wastewater to expand and enhance water supply alternatives.
The 2012 Guidelines for Water Reuse was developed by COM 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 COM 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. Eisner, P.E., South Florida Water Management District
• Wm. Bart Mines, P.E., Trinity River Authority of Texas
2012 Guidelines for Water Reuse xix
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Carrie Miller, EPA, Office of Ground Water and Drinking Water
• Craig Riley, Washington State Department of Health
• Joan B. Rose, PhD, Michigan State University
• Valerie Rourke, CPSS, CNMP, Virginia Department of Environmental Quality
Special thanks go to our colleagues who took their time to share professional experiences and technical
knowledge in reuse to make these guidelines relevant and interesting. These contributors provided text or case
studies; contributors who compiled and/or edited major sections of text are indicated with an asterisk (*). In
addition, some members of the technical review committee contributed significant contributions of text. Please
note that the listing of these contributors does not necessarily identify them as supporters of this document or
represent their ideas or opinions on the subject. These persons are leaders in the field of water reuse, and their
expertise has added to the depth and breadth of the document.
Solomon Abel, P.E.
COM Smith
San Juan, Puerto Rico
Constantia Achileos, MSc
Sewerage Board of Limassol Amathus
Limassol, Cyprus
Robert Adamski, P.E., BCEE
Gannett Fleming
Wood bury, NY
Pruk Aggarangsi, PhD
Energy Research and Development
Nakornping, Chiang Mai University
Chaing Mai, Thailand
Sohahn Akhtar
COM 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
COM 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
Institute- 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.
CH2MHNI
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"Katharine Bell, PhD, P.E., BCEE
COM 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 Re-
inventing the Nation's Urban Water Infrastructure
(ReNUWIT), Stanford University
Stanford, CA
Jacob Boomhouwer, P.E.
COM Smith
Portland, OR
Lucas Botero, P.E., BCEE
COM 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, Ml
Laura Burton
COM Smith
Cambridge, MA
Laura Cameron, BSBM
City of Clearwater
Clearwater, FL
Celeste Cantu
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.
COM Smith
Irvine, CA
Peter Chapman
Sydney Water Corporation
Penrith, New South Wales, Australia
Cody Charnas
COM Smith
Denver, CO
Ana Maria Chavez, Eng, MSc
University of Piura
Piura, Peru
Rocky Chen, P.E.
Oklahoma Department of Environmental Quality
Oklahoma City, OK
Henry Chin, PhD
The Coca-Cola Company
Atlanta, GA, US
Richard Cisterna
Natural Systems Utilities, Inc.
Hillsborough, NJ
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Joseph Cleary, P.E., BCEE
HDR/HydroQual
Mahwah, NJ
Tracy Clinton, P.E.
Carollo Engineers
Walnut Creek, CA
Stacie Cohen
COM Smith
Cambridge, MA
Octavia Conerly
EPA Office of Science and Technology
Washington, D.C.
Teren Correnti
COM 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.
COM Smith
Carlsbad, CA
*Allegra K. da Silva, PhD
COM Smith
Wethersfield, CT
Walter Daessle-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
Maria Dalton
City of Raleigh, NC
Raleigh, NC
Dnyanesh V Darshane, PhD, MBA
The Coca-Cola Company
Atlanta, GA
William Davis
COM 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
Jorg Drewes, PhD
Colorado School of Mines
Golden, CO
William Dunivin
Orange County Water District
Fountain Valley, CA
Yamaji Fiji
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
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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
COM 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
COM 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.
COM Smith
Louisville, KY
Leila Goodwin, P.E.
Town of Gary
Gary, NC
Charles G. Graf, R.G.
Arizona Department of Environment Quality
Phoenix, AZ
Thomas Grizzard, PhD, P.E.
Virginia Tech
Manassas, VA
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Amit Gross, PhD
Ben Gurion University of the Negev
Sede Boqer, Midreshet Ben Gurion, Israel
*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
*KenC. 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
Switzerland
Muttenz, Switzerland
Abigail Holmquist, P.E.
Honeywell
Des Plaines, IL
Sciences Northwestern
Robert Hultquist
California Department of Public Health
El Cerrito, CA
Christopher Impellitteri, PhD
US Environmental Protection Agency
Cincinnati, OH
loanna loannidou, MSc, MBA
Larnaca Sewerage and Drainage Board
Larnaca, Cyprus
Kevin Irby, P.E.
COM Smith
Raleigh, NC
*JillianJack, P.E.
COM 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.
CH2MHILL
Atlanta, GA
Raymond Jay
Metropolitan Water District
Los Angeles, CA
Blanca Jimenez-Cisneros, PhD
Universidad Nacional Autonoma de Mexico
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
RonyJoel, P.E., DEE
AEC Water
Marco Island, FL
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Grace Johns, PhD
Hazen and Sawyer
Hollywood, FL
Daniel Johnson, P.E.
COM Smith
Atlanta, GA
Jason Johnson, P.E.
COM 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.
COM 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
COM 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
COM Smith
Helena, MT
Katsuki Kimura, Dr.Eng.
Hokkaido University
Sapporo, Japan
Kenneth Klinko, P.E.
COM 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.
COM Smith
Cambridge, MA
Richard Leger, CWP
City of Aurora
Aurora, CO
Elizabeth Lemonds
Colorado Department of Public Health and
Environment
Denver, CO
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Liping Lin
GE Water and Power
Beijing, China
Enrique Lopez Calva
COM Smith
San Diego, CA
Maria Loucraft
City of Pompano Beach
Pompano Beach, FL
Karen Lowe, P.E.
COM Smith
Tampa, FL
Alex Lumb
COM Smith
Cambridge, MA
Linda Macpherson
CH2MHILL
Portland, OR
Peter Macy, P.E.
COM Smith
Pretoria, South Africa
Ben Manhas
New Jersey Department of Environmental Protection
Trenton, NJ
MikeMarkus, P.E., D.WRE
Orange County Water District
Fountain Valley, CA
W. Kirk Martin, P.G.
COM 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
COM 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
COM 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
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Wade Miller
WateReuse Association
Alexandria, VA
*Dianne Mills
COM 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 Politecnica de Cataluna
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
COM Smith
Newport News, VA
John Emmanuel T. Pabilonia
USAID
Alexia Panayi, MBA
Water Development Department
Nicosia, Cyrpus
Lynne Pantano
Consultant
Orange County, CA
lacovos 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.
COM Smith
Los Angeles, CA
Mehul Patel, P.E.
Orange County Water District
Fountain Valley, CA
Thomas Pedersen
COM Smith
Cambridge, MA
2012 Guidelines for Water Reuse
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Harold Perry
King County, WA
Seattle, WA
Danielle Pieranunzi, LEED AP BD+C
Sustainable Sites Initiative
Austin, TX
Belinda Platts, MSc
Monterey Regional Water Pollution Control Agency
Monterey, CA
Megan H. Plumlee, PhD, P.E.
Kennedy/Jenks Consultants
San Francisco, CA
H. Plummer, Jr., P.E., BCEE
Alan Plummer Associates, Inc.
Fort Worth, TX
Jim Poff
Clayton County Water Authority
Morrow, GA
Arlene Post
COM 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
COM 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
Gary, NC
Marcia Rinker
COM 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
Comisfon Estatal del Agua
San Luis Potosf, 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.
COM Smith
Irvine, CA
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2012 Guidelines for Water Reuse
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A. Robert Rubin, PhD
Professor Emeritus, NC State University
Raleigh, NC
Jorge Rubio, PhD, DIG
Universidade Federal do Rio Grande do Sul
Porto Alegre, Brazil
Llufs 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
COM Smith
Austin, TX
Michael Schmidt, P.E., BCEE
COM 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 Scares, 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
2012 Guidelines for Water Reuse
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Mary Stahl, P.E.
Olsson Associates
Golden, CO
*Emilie Slander, 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.
COM Smith
Maitland, FL
*Patricia Tennyson
Katz and Associates
San Diego, CA
Michael Thomas
CCWA
Morrow, GA
Donald Thompson, PhD, P.E.
COM Smith
Jacksonville, FL
Ching-Tzone Tien, PhD, P.E.
Maryland Department of the Environment
Baltimore, MD
Jennifer Troy
COM Smith
Cambridge, MA
Ryujiro Tsuchihashi, PhD
AECOM
Burnaby, BC, Canada
Anthony Van
City of San Diego
San Diego, CA
Emmanuel Van Houtte
IWVA, 'Intercommunale Waterleidingsmaatschapy
van Veurne-Ambacht' translated 'Intermunicipal
Water Company of the Veurne Region'
Doornpannestraat, Koksyde, Belgium
*Don Vandertulip, P.E., BCEE
COM Smith
San Antonio, TX
MilindWable, 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
COM 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.
COM Smith
Cambridge, MA
Gregory D Wetterau, P.E., BCEE
COM Smith
Raleigh, NC
Carolyn Ahrens Wieland
Booth, Ahrens & Werkenthin, PC
Austin, TX
Michael Wilson, P.E.
CH2MHILL
Boston, MA
Anna Wingard
COM Smith
New York, NY
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2012 Guidelines for Water Reuse
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*l_ee Wiseman, P.E., BCEE
COM Smith
Orlando, FL
Chester J. Wojna
The Coca-Cola Company
Atlanta, GA
Steven Wolosoff
COM Smith
Rancho Cucamonga, CA
Chee Hoe Woo, MSc
Singapore Public Utilities Board
Singapore
Mauri L. Wood
COM 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
Fiji 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
COM Smith
Cambridge, MA
Ronald Young, P.E., DEE
Elsinore Valley Municipal Water District
Lake Elsinore, CA
Rafael Zaneti, MSc
Universidade Federal do Rio Grande do Sul
Porto Alegre, Brazil
Maribel Zapater, MSc
University of Piura
Piura, Peru
Max Zarate-Bermudez.MSc, MPH, PhD
CDC/NCEH
Atlanta, GA
Meiyang Zhou, MSc
Ben Gurion University of the Negev
Sede Boqer, Midreshet Ben Gurion, Israel
Christine Ziegler
Rodale Institute
Kutztown, PA
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The following individuals also provided special assistance or review comments on behalf of EPA:
Robert K. Bastian
EPA Office of Wastewater Management
Washington, D.C.
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
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2012 Guidelines for Water Reuse
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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
ME microfiltration
NDMA /V-nitrosodimethylamine
NPDES National Pollutant Discharge Elimination System
PPCP Pharmaceuticals and personal care product
PCR polymerase chain reaction
POC paniculate organic carbon
RO reverse osmosis
SAT soil-aquifer treatment
SDWA Safe Drinking Water Act
SRT solids retention time
IDS 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
USAGE U.S. Army Corps of Engineers
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USAID U.S. Agency for International Development
USDA U.S. Department of Agriculture
WHO World Health Organization
WPCF water pollution control facility
WRF water reclamation facility
WRA WateReuse Association
WRRF WateReuse Research Foundation
WWTF wastewater treatment facility
WWTP wastewater treatment plant
xxxiv 2012 Guidelines for Water Reuse
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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 reg-
ulatory 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
Figure 1-1
The 2004 EPA Guidelines for
Water Reuse has had global
influence.
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.
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 COM 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
2012 Guidelines for Water Reuse
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Chapter 1 | Introduction
necessary to revise its guidelines document to include
updated information. As a result, facilitated workshops
and informational sessions were initiated in 2009 at
water events around the world to generate feedback
about concepts that should be repeated, updated,
added, or removed from the document; the current
version of the Guidelines for Water Reuse
incorporates this information.
In states and nations where standards do not exist or
are being revised or expanded, the EPA guidelines
can assist in developing reuse programs and
appropriate regulations. The guidelines also will be
useful to engineers and others involved in the
evaluation, planning, design, operation, or
management of water reclamation and reuse facilities.
Because the number of reuse applications has
expanded so significantly since publication of the 2004
document, this revision has modified the format and
scope of case studies to provide readers with
examples of best practices and lessons learned.
Additionally, the chapter on international reuse has
been expanded to include a discussion of principles for
mitigating risks associated with wastewater use where
treatment does not exist and enabling factors for
expanding wastewater treatment to promote the
increase of water reuse. The chapter also provides
case studies of global experiences that can inform
approaches to reuse in the United States.
1.2 Overview of the Guidelines
Stakeholder input was gathered from a wide range of
contributors in order to identify key themes to
emphasize in this update. The stakeholder
involvement process is described in further detail in
Updating the Guidelines. This input has been
integrated throughout the document, which has been
arranged by topic and devotes separate chapters to
each of the key technical, financial, legal and
institutional, and public involvement issues. While the
document generally follows the outline of the 2004
guidelines, integration of some of the new materials
resulted in expanded chapters that required minor
reorganization. The document is organized into nine
chapters and six appendices, as outlined in Table 1-1.
Throughout the text, case studies are introduced and
referenced by a [code name] in brackets. In the
compiled pdf version of this document, hyperlinks will
direct the reader to the case studies in the appendices.
The U.S. case studies are listed and contained in
Appendix D. International case studies are listed and
contained in Appendix E.
1.3 Guidelines Terminology
The terminology associated with treating municipal
wastewater and reusing it varies both within the United
States and globally. For instance, although the terms
are synonymous, some states and countries use the
term reclaimed water while others use the term
recycled water. Similarly, the terms water recycling
and water reuse have the same meaning. In this
document, the terms reclaimed water and water reuse
are used. Definitions of terms used in this document,
with the exception of their use in case studies, which
may contain site-specific terminology, are provided
below.
De facto reuse: A situation where reuse of treated
wastewater is, in fact, practiced but is not officially
recognized (e.g., a drinking water supply intake
located downstream from a wastewater treatment
plant [WWTP] discharge point).
Direct potable reuse (DPR): The introduction of
reclaimed water (with or without retention in an
engineered storage buffer) directly into a drinking
water treatment plant, either collocated or remote from
the advanced wastewater treatment system.
Indirect potable reuse (IPR): Augmentation of a
drinking water source (surface or groundwater) with
reclaimed water followed by an environmental buffer
that precedes drinking water treatment.
Nonpotable reuse: All water reuse applications that
do not involve potable reuse.
Potable reuse: Planned augmentation of a drinking
water supply with reclaimed water.
1-2
2012 Guidelines for Water Reuse
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Chapter 1 | Introduction
Table 1-1 Organization of 2012 Guidelines for Water Reuse
Chapter Overview of Contents
Chapter 2-Planning and
Management
Considerations
Chapter 3-Types of
Reuse Applications
Chapter 4-State
Regulatory Programs for
Water Reuse
Chapter 5-Regional
Variations in Water Reuse
Chapter 6-Treatment
Technologies for
Protecting Public and
Environmental Health
Chapter 7-Funding Water
Reuse Systems
Chapter 8-Public
Outreach, Participation,
and Consultation
Chapter 9-Global
Experiences in Water
Reuse
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
APPENDIX F
APPENDIX G
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.
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.
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.
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.
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.
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.
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.
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.
Federal and nonfederal agencies that fund research in water reuse
Inventory of water reuse research projects
State regulatory websites
Case studies on water reuse in the United States
Case studies on water reuse outside the United States
List of case studies that were included in the 2004 EPA guidelines
Abbreviations for names of states and units of measure
2012 Guidelines for Water Reuse
1-3
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Chapter 1 | Introduction
Reclaimed water: Municipal wastewater that has
been treated to meet specific water quality criteria with
the intent of being used for a range of purposes. The
term recycled water is synonymous with reclaimed
water.
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
Urban Reuse
Unrestricted
Restricted
Description
The use of reclaimed water for nonpotable applications in municipal settings
where public access is not 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 Non-
food Crops
The use of reclaimed water to irrigate crops that are either processed before
human consumption or not consumed by humans
Unrestricted
Impoundments
Restricted
The use of reclaimed water in an impoundment in which no limitations are
imposed on body-contact water recreation activities
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
DPR
Augmentation of a drinking water source (surface or groundwater) with reclaimed
water followed by an environmental buffer that precedes normal drinking water
treatment
The introduction of reclaimed water (with or without retention in an engineered
storage buffer) directly into a water treatment plant, either collocated or remote
from the advanced wastewater treatment system
1-4
2012 Guidelines for Water Reuse
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Chapter 1 | Introduction
1.4 Motivation for Reuse
The ability to reuse water, regardless of whether the
intent is to augment water supplies or manage
nutrients in treated effluent, has positive benefits that
are also the key motivators for implementing reuse
programs. These benefits include improved
agricultural production; reduced energy consumption
associated with production, treatment, and distribution
of water; and significant environmental benefits, such
as reduced nutrient loads to receiving waters due to
reuse of the treated wastewater. As such, in 2012, the
drivers for reuse are similar to those presented in the
2004 guidelines and center around three categories: 1)
addressing urbanization and water supply scarcity, 2)
achieving efficient resource use, and 3) environmental
and public health protection.
1.4.1 Urbanization and Water Scarcity
The present world population of 7 billion is expected to
reach 9.5 billion by 2050 (USCB, n.d.).
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
2012 Guidelines for Water Reuse
1-5
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Chapter 1 | Introduction
water typically offsets potable water use and is used
locally. For example, about 20 percent of California's
electricity is consumed by water-related energy use,
including potable water conveyance, storage,
treatment, and distribution and wastewater collection,
treatment, and discharge (California Energy
Commission, 2005). Although additional energy is
required to treat wastewater for reclamation, the
amount of energy required for treatment and transport
of potable water is generally much greater in southern
California. And the estimated net energy savings could
range from 0.7 to 1 TWh/yr, or 3,000 to 5,000
kWh/Mgal. At a power cost of $0.075/kWh, the savings
would be on the order of $50 to $87 million per year
(Schroeder et al., 2012).
Figure 1-2
Purple pipe is widely used for reclaimed water
distribution systems (Photo credit: COM 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].
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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:
Drinking
Water
Raw
Water
Wastewater
"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
Reuse*
Reuse
* Level of treatment depends
on the reuse application
Reuse"
Figure 1-3
Treatment technologies are available to achieve any desired level of water quality
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Chapter 1 | Introduction
source sufficient to meet the quality appropriate for the
intended use. By selecting appropriate treatment for
specific applications, water supply costs can be
controlled and the costs for improved wastewater
treatment technologies delayed until they are balanced
by the benefits. Consideration must also be balanced
with the potential for future reuse of higher reclaimed
water quality such that these uses are not limited.
1.6 References
Bates, B. C., Z. W. Kundzewicz, S. Wu, and J. P. Palutikof.
2008. Climate Change and Water. Technical paper.
Intergovernmental Panel on Climate Change. Geneva.
Brown, L. R. 2011. "The New Geopolitics of Food," Foreign
Policy, 4, 1-11. California Department of Water Resources
(2011). Notice to State Water Project Contractors. State
Water Project Analyst's Office. Retrieved August 2012 from
.
California Energy Commission. 2005. Final Staff Report,
California's Water-Energy Relationship, CEC-700-2005-011-
SF. Retrieved August 2012 from
.
National Conference of State Legislatures (NCSL). 2009.
Overview of the Water-Energy Nexus in the U.S. Retrieved
August 2012 from .
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 Meat-
based and Plant-based Diets and the Environment."
American Journal of Clinical Nutrition. 78(3) :660S-663S.
Rodrigo, D., E. J. Lopez Calva, and A. Cannan. 2012. Total
Water Management. EPA 600/R-12/551. U.S. Environmental
Protection Agency. Washington, D.C.
Schroeder, E., G. Tchobanoglous, H. L. Leverenz, and T.
Asano. 2012. Direct Potable Reuse: Benefits for Public
Water Supplies, Agriculture, the Environment, and Energy
Conservation, National Water Research Institute (NWRI)
White Paper, Publication Number NWRI-2012-01. Fountain
Valley, CA.
United States Census Bureau (USCB). n.d. World
Population. Accessed on September 17, 2012 from
.
U.S. Environmental Protection Agency (EPA). 1980. Protocol
Development: Criteria and Standards for Potable Reuse and
Feasible Alternatives. 570/9-82-005. Environmental
Protection Agency. Washington, D.C.
U.S. Environmental Protection Agency (EPA). 1992.
Guidelines for Water Reuse. 625/R92004. Environmental
Protection Agency. Washington, D.C.
U.S. Environmental Protection Agency (EPA). 2004.
Guidelines for Water Reuse. 625/R-04/108. Environmental
Protection Agency. Washington, D.C.
U.S. Environmental Protection Agency (EPA). 2012.
EnergyAA/ater. Retrieved August 2012 from
.
World Commission on Environment and Development
(WCED). 1987. Our Common Future: The Bruntland Report.
United Nations World Commission on Environment and
Development. Oxford University Press. New York, NY.
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2012 Guidelines for Water Reuse
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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 non-
peak 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.
Traditional Water Management (Non-integrated Water Resources)
Water Supply
Wastewater
Receiving
Waters
Stormwater
weather
Total Water Management (Integrated Water Resources)
Beneficial reuse of stormwater
(e.g., groundwater recharge)
Water Supply
Wastewater
dry
weather
Stormwater
Reclaimed water
Reduced flows
from BMPs
Receiving
Waters
Figure 2-1
Traditional versus Integrated Water Management
(adapted from O'Connor et al., 2010)
This approach can result in detrimental environmental
impacts and lead to inefficiencies in the use of water.
Integrated water management significantly improves
the opportunities to obtain benefits from water,
regardless of the stage in the water cycle. Concepts
such as integrating water conservation practices to
reduce the demand for freshwater are part of this
comprehensive management approach. Also, rather
than viewing stormwater as a nuisance, it should be
considered an asset that is allowed to recharge
groundwater through best management practices
(BMPs), such as the use of swales, porous pavement,
or cisterns. Additionally, wastewater can be reused,
providing both environmental and water supply
benefits.
The end result of integrated water management is
reduced discharges to receiving waters and reduced
reliance on surface and groundwater supplies to meet
water demands. The following set of management
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Chapter 2 | Planning and Management Considerations
strategies and alternative resources are typically
considered in an integrated water management plan:
• Water conservation
• Reuse of wastewater
• Reuse of graywater
• Stormwater BMPs
• Rainwater harvesting
• Enhanced groundwater recharge
• Increased surface water detention
• Dry weather urban runoff treatment
• Dual plumbing for potable and nonpotable uses
• Separate distribution systems for fire protection
• Multi-purpose infrastructure
• Use of the right water quality for intended use
• Green roofs
• Low impact development (LID)
An example of this new approach to water resources
planning is the Integrated Resources Plan (IRP) of Los
Angeles, Calif. In 1999, Los Angeles embarked on an
entirely new approach for managing its water
resources. The IRP took a holistic, watershed
approach by developing a partnership among different
city departments that managed water supply,
wastewater, and stormwater (CDM, 2005; Lopez 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 well-
supported 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
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Chapter 2 | Planning and Management Considerations
management alternatives is provided in the research
report titled, Extending the Integrated Resource
Planning Process to Include Water Reuse and Other
Nontraditional Water Sources (WRRF, 2007a). The
report provides an extensive description of each of the
elements of the IRP process, the issues and
opportunities related to incorporating reuse into
integrated plans, and the tools and models that can be
used for facilitating appropriate reuse applications into
an integrated management plan. Additional information
is also provided in the document, Total Water
Management (Rodrigo et al., 2012).
Integral to the successful implementation of integrated
water management is a regulatory framework that
facilitates rather than obstructs this approach. The
various managed components of an integrated water
resources plan, which may include water, wastewater,
stormwater, reclaimed water, and energy, may be
regulated by different state agencies and, in some
cases, one component may be regulated by more than
one state agency. Some state agencies, particularly
those that have been delegated Clean Water Act
(CWA), NPDES, and Safe Drinking Water Act (SDWA)
federal programs, have deliberately elected to
establish clear boundaries to avoid any potential for
redundancy and confusion for the public. In the case of
an IPR proposal, however, aspects of the project might
require involvement and possibly permitting by multiple
agencies. The degree of coordination and cooperation
that can be achieved may vary from project to project
and from state to state. Therefore, states committed to
achieving integrated water resources planning goals
may choose to adopt laws that consolidate regulatory
programs to the extent possible or improve the
coordination and cooperation among programs of
different state agencies for the purpose of facilitating
this planning framework. Subsequently, regulatory
programs developed on the basis of these laws should
provide greater focus and details on implementation of
more integrated solutions.
2.2 Planning Municipal Reclaimed
Water Systems
Regardless of the size and type of a reclaimed water
system, there are planning steps that should be
considered (although an industrial process recycle
system may have different process control drivers).
Planning should be consistent with the overall water
resources management objectives, which should be
defined through an integrated planning process
(Section 2.1). As part of an integrated water resources
plan, a reclaimed water master plan can identify
acceptable community uses for reclaimed water,
potential customers and their demands, and the quality
of water required. Planners must also determine the
volume of reclaimed water available for distribution,
paying attention to the diurnal discharge curve at the
community WWTP. This is an important consideration
that can drive many other planning decisions as water
conservation practices often require evening or early
morning irrigation when low flows to the WWTP occur.
If irrigation will occur during low influent wastewater
periods, the supply of reclaimed water may not be
adequate to meet the instantaneous demands, unless
the reclaimed water demand rate is low compared to
current treatment plant capacity. Storage is one option
to resolve this supply/demand imbalance.
As part of the initial viability assessment, it is critical to
examine federal and state laws, regulations, rules, and
policies. Frameworks of state regulations are
described in Chapter 4. In addition to the state
regulatory context, certain overarching federal and
state natural resource and environmental impact laws
apply at the planning stage. The National
Environmental Policy Act (NEPA) requires an
assessment of environmental impacts for all projects
receiving federal funds and subsequent mitigation of
all significant impacts. Many states also have
equivalent rules that mandate environmental impact
assessment and mitigation planning for all projects
prior to construction. These requirements often
stipulate terms of public review. Even in cases where it
is not legally required, stakeholder involvement in the
planning of a water-reuse system is important and can
help to achieve a successful outcome, as described in
Chapter 8.
Other laws protect biological, scenic, and cultural
resources. These laws can result in a de facto
moratorium on the construction of large-scale water
diversions (by dams) that flood the habitat of protected
species or inundate pristine canyons or areas of
historical significance. These laws are of particular
relevance where new water supply is under
consideration. In some cases these laws make reuse
more attractive than new source development, but
they may impact seasonal storage options for
reclaimed water.
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Chapter 2 | Planning and Management Considerations
To further examine project viability, the following
project-planning steps taken from the WateReuse
Association Manual of Practice serve as a guide
(WRA, 2009):
A. Identify quantity of reclaimed water available
B. Screen all existing and potential future uses and
users
C. Identify potential users
D. Determine if users will accept reclaimed water
E. Compare supply to potential demand
F. Prepare distribution system layout
G. Finalize customer list
H. Determine economic feasibility
I. Compile final user list and distribution
J. Prepare point-of-sale facilities
K. Obtain regulatory approval
L. Perform on-site retrofits
M. Perform cross-connection test
N. Begin delivering water
While the WateReuse Association Manual of Practice
provides details on each of these steps, a number of
considerations are worth further exploration.
2.2.1 Identifying Users and Types of
Reuse Demands
Because permitted uses vary greatly between states, a
review of individual state regulations is important so
the utility has a thorough understanding of how
reclaimed water is regulated and what uses are
allowed. Once regulations and allowed uses are fully
understood, a utility may review water usage records
to identify and locate some of its largest users.
Focusing first on the largest water users helps the
utility get the best possible return on investment, as
well as maximize its benefits to the potable water
system. In addition to water records, aerial
photographs can be useful in identifying users who
could utilize reclaimed water for irrigation purposes
(such as golf courses and other recreational facilities).
Variables such as an area's climate, state regulations,
and common industries will determine the best
potential reclaimed water customers. Irrigation of golf
courses and recreational facilities may be the most
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
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Chapter 2 | Planning and Management Considerations
zoning regulations and similar restrictions. Developers
of approved areas for new development may be
required to prepare specific plans that demonstrate
sufficient water supply or wastewater treatment
capacity. In these contexts, dual-piped systems may
be developed at the outset of development. It is
important that any reuse project conforms to
requirements under the general plan to ensure the
project does not face legal challenges on a land use
basis. Local planning processes often include public
notice and hearings. As the public may have many
misconceptions about reclaimed water, it is important
for planners to address public concerns or opposition,
as described in depth in Chapter 8.
Chapter 5 of the 2004 guidelines identified land use
and environmental regulation controls used by local
government entities to implement and manage
reclaimed water systems; this chapter also identified
mandatory use requirements in California. Since
publication of the 2004 guidelines, many communities
and states have implemented more formal water
planning processes to meet public health needs for
adequate water, wastewater, and reclaimed water
services. There are several reasons a utility might
create a local policy to require connection to a
reclaimed water system, with parallel logic used in
many communities to require connection to municipal
utilities when reasonably available. The most common
reason to require connection is to assure use of the
new system, adequate to shift some of the water
demand and to pay for the new system or defer new
potable main construction. In an integrated water
management program, potable water supplies may be
limited and require construction of a reclaimed
water/dual water system to meet the total demand.
Even if reclaimed water is priced lower than the
potable supply, the public may not have been
adequately informed to understand the benefits of a
diversified water system and may resist conversion to
reclaimed water.
Mandatory connection to reclaimed water systems is
becoming more common. Planning for future use of
reclaimed water allows communities to require certain
uses to utilize reclaimed water if reasonably available.
Because construction cost for retrofit with a dual water
system is higher and disruption of other infrastructure
is unavoidable, dual water piping can be installed
initially with the nonpotable distribution system
dedicated to irrigation, cooling towers, or industrial
processes. When reclaimed water is available to the
development area, a connection to the supply is the
only local construction required.
Utilities may also need to secure bonds used for
construction with an ordinance requiring connection to
a reclaimed water system, thus providing a guarantee
of future cash flow to meet bond payments. In addition
to state legislative action in California (identified in
Chapter 5 of the previous guidelines), many utilities
have included mandatory connection language. Water
Recycling Funding Program Guidelines initially issued
in 2004 and amended in July 2008 require loan/grant
applicants to include a draft mandatory use ordinance
in their application packet (SWRCB, 2009). Text in the
Marina Coast Water District Ordinance, Title 4,
4.28.030 Recycled water service availability, includes:
A. When recycled water is available to a particular
property, as described in Section 1.04.010, the
owner must connect to the recycled water
system. The owner must bear the cost of
completing this connection to the recycled water
system.
B. New water users who are not required to
connect to recycled water because the distance
to the nearest recycled water line is greater than
the distance provided in Section 1.04.010, shall
be required to construct isolated plumbing
infrastructure for landscape irrigation or other
anticipated nonpotable uses, with a temporary
connection to the potable water supply.
C. All new private or public irrigation water
systems, whether currently anticipating
connection to the recycled system or that shall
be connected to the potable water system
temporarily while awaiting availability of
recycled water, shall be constructed of purple
polyvinyl chloride (PVC) pipe to the existing
district standard specification" (Marina Coast
Water District, 2002).
Examples of other California utilities with mandatory
connection requirements include Dublin San Ramon
Services District (DSRSD); Inland Empire Utility
Agency; San Luis Obispo Rowland Heights;
Cucamonga Valley Water District; and Elsinore Valley
Municipal Water District. Florida is another state with
mandatory connection requirements; 78 counties,
cities, and private utilities responded on their 2011
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Chapter 2 | Planning and Management Considerations
annual reuse reports that they either require
construction of reclaimed water piping in new
residential or other developments or require
connection to reuse systems when they become
available. The Florida communities of Altamonte
Springs; Boca Raton; Brevard, Charlotte, Polk,
Colombia, Palm Beach, and Seminole Counties;
Marco Island; and Tampa are examples. There are no
communities in Texas with mandatory connections, but
requirements were also found in Yelm, Wash.; Gary,
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 micro-
spray, 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 re-
establish 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.
EPA 816-R-03-002 (EPA, 2003).
To develop a robust reclaimed water distribution
system, it is important to provide an initial "backbone,"
or primary transmission main, of sufficient size to allow
the system to carry reclaimed water away from the
source. The primary transmission main should be
constructed in a location that will allow for connections
to future lines as well as easy connection to previously
identified large potable water users. Several items
should be considered when evaluating potential routes
for the primary transmission main of a reclaimed water
distribution system, including:
• The location of previously identified potential
users
• The total amount of potable water to be saved
by connecting these potential users to the
reclaimed water distribution system
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Chapter 2 | Planning and Management Considerations
• The amount of potable water to be saved that is
not dependent on weather or climate conditions
• Other potential 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 identi-
fied 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 Fjgure2.2
Antonio Water 36_jnch CSC 301 purple mortar
System (SAWS). pipe, San Antonio Water System
(Photo credit: Don Vandertulio)
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Chapter 2 | Planning and Management Considerations
Where utility preference or construction conditions
dictate the use of other pipe material, such as ductile
iron pipe, purple plastic sleeves can be used to
provide corrosion control and identify the water main
as a reclaimed water main. Likewise, steel pipe can be
painted and high density polyethylene (HOPE) pipe
can be ordered with purple stripes integral to the pipe.
Separation distances are required between reclaimed
water pipes and water and sewer pipes, typically
identified as 9 or 10 ft (3 m) pipe-to-pipe horizontal
separation between reclaimed water and potable water
piping. The same provision typically applies to
separation distance between a reclaimed water pipe
and a sanitary sewer main. Where a crossing occurs,
the pipe with the highest quality product should be
located above the other two, with 1 ft (0.3 m) vertical
separation between any two pipes. Specifically,
potable pipe should be above reclaimed water pipe,
and reclaimed water pipe should be above the sanitary
sewer main, as shown in Figure 2-3.
2.2.3.2 Reclaimed Water Appurtenances
Reclaimed water distribution systems will have all of
the appurtenances typical of a potable water system.
Most of the typical system components are now
available in purple to support increased installation of
purple color-coded reclaimed water systems. Valve
riser covers are often triangular or square to
distinguish them from potable water covers; reclaimed
water system valves can be ordered as plant valves
with opposite open and close positions from potable
valves. Backflow prevention devices, air relief valves,
meter boxes, and sprinkler heads are all available in
purple. All components and appurtenances of a
nonpotable system should be clearly and consistently
identified throughout the system. Identification should
be through color coding and marking so that the
nonpotable system (i.e., pipes, pumps, outlets, and
valve boxes) is distinctly set apart from the potable
system. The methods most commonly used are unique
colorings, labeling, and markings.
Location of Public Water System Mains in Accordance with F.A.C. Rule 62-555.314
Other Pipe
Storm Sewer,
Storniwater Force Main,
Reclaimed Water (2)
Vacuum .Sanitary Sewer
Gravity or Pressure
Sanitary Sewer,
Sanitary Sewer Force Main,
Reclaimed Water (4)
On-Sile Sewage Treatment &
Disposal System
Horizontal Separation
] Water Main [
4
1
3 ft. minimum
i
1
Water Main
10ft. preferred
3 ft. minimum
Water Main 1
10 ft. preferred
6 11 minimum (3)
>
10 ft. minimum
Crossings (1)
C
J
1
) Water Main
12 inches is the minimum.
except for storm sewer, then
6 inches is the minimum and
12 inches is preferred
C
1
J Water Main
1 2 inches preferred
6 inches minimum
<
_) Water Main
.
12 inches is the minimum.
except for gravity sewer. Ihen
6 inches is the minimum and
12 inches is preferred
—
Joint Spacing a, Crossings
(Full Joint Centered)
Alternate 3 ft. minim
lllll
|| | Water Main [ Q
—
Alternate 3 \\. minimum
! ] | Water Main | j \
=
Alternate 6 ft. minim
u in
if | WalcrMain | ||
—
(1) Water main should cross above other pipe. When water main must he below other pipe, the minimum separation is 12 inches.
(2) Reclaimed water regulated under Part IH of Chapter 62-610. !•". A C.
(3) 3 ft. for gravity sanitary sewer where the bottom of the water main is laid at least (> inches above the top of the gravity sanitary sewer.
(4) Reclaimed water not regulated under Part III of Chapter 62-610. F.A.C.
Figure 2-3
Appropriate separation of potable, reclaimed water, and sanitary sewer pipes (FDEP, n.d.)
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Chapter 2 | Planning and Management Considerations
A reclaimed water distribution system typically requires
signage at facilities (e.g., pump stations, storage, etc.),
and some states require marking of utility pipelines
along the alignment. For irrigation components that
incorporate hose bibs, most state regulations require a
locking hose vault or quick connection assembly to
preclude unauthorized connection and use of the
reclaimed water. Purple asset identification tags can
be attached to valve box lids, valve handles, backflow
preventers, and other appurtenances to readily identify
these system components. All major irrigation system
suppliers have snap-on components (rings) in purple
that can be added to existing sprinkler heads, as
shown in Figure 2-4. Purple Mylar pre-printed stickers
are also popular and can be wrapped around pop-up
sprinkler heads to identify the system as providing
reclaimed water.
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, cross-
connection 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 cross-
connection problem that, to date, is unresolved.
Figure 2-4
Purple snap-on reclaimed water identification cap
(Photo credit: Rain Bird)
Color coding of utility piping systems has been
practiced for decades, and the roots of the current
American National Standard Institute (ANSI) Standard
Z-535 color standard in the United States can be
traced back to the July 16, 1945 American Standard
Association (ASA) approval of safety color standards
at the request of the War Department (ANSI, 2007).
The American Public Works Association (APWA)
Uniform Color Standard was initially adopted in 1980
(Precaution Blue for water systems and Safety Green
for sewer systems), and an updated policy that added
purple for reclaimed water pipes was adopted in 2003.
The use of purple pipe to designate reclaimed or
recycled water was first adopted by the AWWA
California-Nevada Section in 1997. The California
Department of Health Services and Nevada Division of
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Chapter 2 | Planning and Management Considerations
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, 2011 a).
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 (I PC) 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 I
Arrangement Production Wholesale Distribution Retail Distribution
Separate Authorities
Wholesaler/Retailer System
Joint Powers Authority (for
Production and Distribution only)
Integrated Production and
Distribution
Wastewater Treatment Agency
Wastewater Treatment Agency
Joint Powers Authority
Water/Wastewater Authority
Wholesale Water Agency
Wastewater Treatment
Agency
Joint Powers Authority
Water/Wastewater
Authority
Retail Water Entity
Retail Water Entity
Retail Water Entity
Water/Wastewater
Authority
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Chapter 2 | Planning and Management Considerations
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 [US-
CA-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
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Chapter 2 | Planning and Management Considerations
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 on-
site storage, allowing multiple large users to be
supplied at a constant flow rate over the full 24-hour
day. This can decrease pumping and system storage
requirements. Some utilities, such as the Loxahatchee
River District in Florida, have the ability to curtail
deliveries of reclaimed water to large users through
telemetry-controlled valves once contractual volumes
are met or during periods of extremely high demand.
From an operational perspective, maintaining a
chlorine residual in the reclaimed water system is as
important as maintaining a residual in the potable
water system. Public health decisions should control
design decisions; maintaining good bacteriological
quality in a reclaimed water system where occasional
contact with the public is likely dictates monitoring and
control measures. This could include chlorine residual
analyzers at system storage and booster pump
stations to confirm adequate chlorine residuals and
systems to add incremental amounts of disinfectant to
maintain high water quality. Operational practices that
decrease water age by keeping the reclaimed water
moving through the system can also improve the
quality of the delivered water and decrease system
maintenance efforts. Maintaining positive water
movement during low-flow/low-demand periods of the
year can be accomplished by operating tanks at lower
elevations or by having a discharge point at the far
ends of the reclaimed water distribution system. In an
ideal design, a large customer with continuous
demands would be located at the end of the system,
ensuring continuous flow through the piping. If there is
an opportunity to include discharge to a creek or other
water feature near the end of the distribution system,
this environmental augmentation can provide a base
flow that will assist in maintaining reclaimed water
quality in the distribution system. Another alternative is
to install air-gap discharges to a sanitary sewer that
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Chapter 2 | Planning and Management Considerations
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 state-
defined 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,
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serious water quality issues were caused by multiple
small effluent discharges into the reservoir. The
Fairfax County Water Authority withdraws water from
the Occoquan Reservoir to meet the water supply
needs of a large portion of northern Virginia. UOSA
was formed in 1971 to address the water quality
problem by the same local government entities that
relied on the reservoir for their water supply.
Therefore, these local governments, and by proxy their
residents, received the benefits of the investments in
additional wastewater treatment, satisfying the first key
component that their water supply was now both
protected and augmented. Regarding the second key
component, the improvements made a dramatic
improvement in the water quality of the reservoir that
was readily visible to the general public. Algae blooms,
foul odors, low dissolved oxygen (DO) for fish, and
other factors were addressed by the regionalization
and additional treatment processes, which provided
the public with a tangible example of a system that
resulted in improved water quality over past practices.
Another example is the Gwinnett County, Ga.,
discharge to Lake Lanier. Lake Lanier is formed by
Buford Dam, which is operated by the U.S. Army
Corps of Engineers (USAGE) 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 USAGE 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. [US-
CA-Los Angeles County].
Other MAR projects have been implemented to aid in
maintaining a salt balance in water supply aquifers, as
demonstrated in a case study on the Santa Ana River
Basin [US-CA-Santa Ana River]. In Arizona, the
Groundwater Management Act allows users to store
recharged water and sell the associated water rights.
This led to the first-ever auction of reclaimed water
rights in Prescott Valley. The ability to bank recharged
reclaimed water provided the versatility necessary for
the auction [US-AZ-Prescott Valley]. In Mexico City,
reclaimed water is being used to recharge the local
aquifer, which is overdrawn by 120 percent, leading to
the subsidence of the soil in some places at a rate of
up to 16 in/yr (40 cm/yr) [Mexico-Mexico City].
(National Water Commission of Mexico, 2010).
MAR systems may be described in terms of their five
major components: a source of reclaimed water, a
method to recharge, sub-surface storage, recovery of
the water, and the final use of the water. One of the
key considerations in MAR is managing the travel time
of reclaimed water before it is recovered for use. As a
result, the identification, selection, and testing of
environmentally-acceptable tracers for measuring
travel times of reclaimed water and its constituents in
recharge systems has been the subject of recent
research. In the research report Selection and Testing
of Tracers for Measuring Travel Times in Natural
Systems Augmented with Treated Wastewater Effluent
(WRRF, 2009), a summary of literature related to
conservative and surrogate tracers for reclaimed water
constituent transport in the subsurface is provided
along with the materials and results from tracer
experiments on three common recharge systems
augmented with reclaimed water, information on the
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process for regulatory approval of the use of tracers
for reclaimed water recharge systems, and field
methods for conducting tracer tests. Reclaimed water
can be directly or indirectly used after sub-surface
storage. Some systems both directly and indirectly use
reclaimed water when demand for irrigation is high and
recharge water for future indirect use when demand
for irrigation is low.
The two primary types of groundwater recharge are
surface spreading and direct injection. Vadose zone
injection wells have been increasing in use as this
technology has become established in recent years.
Figure 2-5 illustrates these recharge methods. Direct
injection wells may also be used as dual-purpose ASR
wells for both recharging and recovering stored water.
The recharge method will depend on the aquifer type
and depth and on the aquifer characteristics, which
impact the ability to recharge water into the storage
zone and later recover that water. The use of recharge
basins and vadose zone injection wells is restricted to
unconfined aquifers, while direct injection systems
may be used in both unconfined and deeper confined
aquifer systems.
storage and the water must be recovered quickly, then
ASR systems might be the only feasible alternative. If
an existing distribution and well system may be utilized
as part of an ASR system, then dual-purpose direct
injection wells might be the best choice. If an
unconfined aquifer is being considered, there are no
constraints on the choice of recharge method.
Is this aquifer
confined or unconfined?
If Unconfined
No constraint on
recharge method.
If Confined
Direct injection
must be used.
What is the depth
of the groundwater?
If less than 330-660 ft,
direct injection may be
cost competitive with
surface recharge.
Ifgreaterthan330-660ft,
surface recharge should be
considered.
Is cost-effective
land available at an
appropriate location?
RECHARGE BASIN
DIRECT
VADOSEZONE INJECTION
INJECTION WELL WELL
VadoseZone
-\7—-
Unconfined Aquifer
Aquitard
Confined Aquifer
Figure 2-5
Commonly used methods in managed aquifer recharge
There are many site-specific variables that affect the
design and selection of the most appropriate MAR
system for a specific application. As shown in Figure
2-6, the first critical question is "what aquifer is being
considered for use in the MAR system?" If a confined
aquifer is being considered, then direct injection is the
only feasible alternative; direct injection may include
either single-use injection wells or the dual-purpose
wells used in ASR systems. If the goal of a
groundwater recharge project is to provide short-term
If no, vadose zone
injection wells maybe
appropriate.
If yes, surface recharge
basins may be
appropriate.
Figure 2-6
Sample decision tree for selection of groundwater
recharge method
For unconfined aquifers, as the depth to groundwater
increases, the cost of direct injection wells increases;
therefore, the effect of depth should be evaluated for
each situation. Land price, location, and availability are
also key considerations. Potential negative impacts
from rising groundwater levels, including groundwater
mounding, must also be considered.
2.3.3.1 Water Quality Considerations
Depending on the method and purpose of groundwater
recharge, most states require either a minimum of
secondary treatment with or without additional filtration
for groundwater recharge. State Underground Injection
Control programs and Sole Source Aquifer Protection
are included under Sections 1422 of the SDWA, which
provides safeguards so that aquifer recharge and ASR
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wells do not endanger current and future underground
sources of drinking water. There is currently no
specific requirement for nutrient removal, but lower
effluent nutrient concentrations required for point-
source 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 A/-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, naturally-
occurring arsenic-containing minerals in the aquifer
matrix may leach into the groundwater due to changes
in oxidation-reduction potential (ORP) during injection,
storage, and recovery. Arsenic in recovered water has
been detected or is a significant concern based on
area ASR projects. Approaches to minimizing arsenic
levels and other trace inorganic leaching/transport can
include controlling the pH and matching the ORP of
the recharge water with the ORP of the ambient
groundwater. For direct injection to a highly permeable
aquifer, such as the Biscayne Aquifer in South Florida,
additional nutrient limits that are stricter than those
required for typical direct injection may be set. The
nutrient requirements address the potential impacts to
nearby surface waters, such as rivers, lakes, canals,
and wetlands that are hydrologically connected and
supported by the aquifer. For the SDWRP, DERM has
a very low ammonia requirement (0.5 mg/L) and
includes phosphorus removal in its antidegradation
water quality requirements.
2.3.3.2 Surface Spreading
Surface spreading is the most widely-used method of
groundwater recharge due to its high loading rates
with relatively low maintenance requirements. At the
spreading basin, the reclaimed water percolates into
the soil, consisting of layers of loam, sand, gravel, silt,
and clay. As the reclaimed water filters through the
soil, these layers allow it to undergo further physical,
biological, and chemical purification through a process
called Soil Aquifer Treatment (SAT); ultimately, this
water becomes part of the groundwater supply. SAT
systems require unconfined aquifers, vadose zones
free of restricting layers, and soils that are coarse
enough to allow for sufficient infiltration rates but fine
enough to provide adequate filtration. A summary and
discussion of the removal mechanisms for pathogens,
organic carbon, contaminants of concern, and nitrogen
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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 surface-
spreading 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.
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Table 2-2 Comparison of vadose zone and direct injection recharge wells
Recharge Method
Vadose Zone Wells
Main Advantages
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
Main Disadvantages
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
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 low-
permeability 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 direct-
injection 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
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design are also used by the cities of Gilbert and
Chandler, Ariz. Reuse projects in other areas, such as
the Seaside Basin in the Monterrey Bay area of
California, have also considered the use of vadose
zone wells because of the depth to groundwater (300+
ft bgs). According to groundwater modeling estimates,
it would take almost 300 days for the water recharged
in the vadose zone to reach the top of the aquifer.
Because of clay layers and other low- permeability soil
lenses, there is minimal control of where the recharged
water enters the underlying aquifer and at what rate.
Rapid Infiltration Trenches. Rapid infiltration
trenches (RITs) are not vadose zone wells, but are
similar in that recharge water is discharged into a
media-filled "hole" or trench. Unlike the vertically-
constructed 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 direct-
injection 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
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zone well will support biological activity and additional
treatment; at the Scottsdale Water Campus,
attenuation of NDMA during sub-surface transport has
been limited with RO-treated water and vadose zone
injection wells.
Direct-injection wells have been used for Orange
County Water District's (OCWD) Talbert Gap Barrier
with water supplied by the Groundwater
Replenishment System (GWRS), for the Dominguez
Gap Barrier with water supplied by the West Basin
Municipal Water District's El Segundo facilities, and for
the Alamitos Barrier with water supplied in part by the
Water Replenishment District's Leo J. Vander Lans
Water Treatment Facility (LVLWTF) [US-CA-Vander
Lans]. Direct-injection wells were also proposed for
Miami-Dade Water and Sewer Department's SDWRP
[US-FL-Miami So District Plant].
2.3.3.4 Recovery of Reclaimed Water through
ASR
ASR allows direct recovery of reclaimed water that has
been injected into a subsurface formation for storage.
ASR can be an effective management tool to provide
reclaimed water storage, minimizing seasonal
fluctuations in supply and demand, by allowing storage
during the wet season when demand is low and
recovery of water during dry periods when demand is
high. Because the potential storage volume of an ASR
system is essentially unlimited, it is expected that
these systems will offer a solution to the shortcomings
of the traditional, engineered storage techniques. ASR
was considered as part of the Monterey County, Calif.,
reuse program to overcome seasonal storage issues
associated with an irrigation-based project. In the
United States, reclaimed water ASR projects are
currently operating in Arizona, Florida, and Texas
(Pyne, 2005; Shrier 2010). Internationally, the only
operating ASR systems identified in literature are
located in Australia.
While ASR is gaining interest, there are considerations
for operation of these systems. Federal Underground
Injection Control (UIC) rules do not allow the injection
of any fluid other than water meeting drinking water
standards into an underground source of drinking
water (USDW), which is defined as having a total
dissolved solids concentration of less than 10,000
mg/L (EPA, 2001). Section 1453 of the 1996
amendments to the SDWA outlines a Source Water
Quality Assessment to achieve maximum public health
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 disrupter compounds, Pharmaceuticals and
personal care products, and microbes (WRRF, 2007b).
SDWA describes the essential steps for every
community to inventory known and potential sources
of contamination within their drinking water sources.
Nutrients and most bacteria are usually removed in
advanced biological wastewater treatment processes.
While most large pathogens are not a concern in most
MAR systems, the reversal of flow in ASR systems
can release materials that are normally removed.
These same treatment processes are also typically
used to remove the other recalcitrant groups of
contaminants listed above. If the TOC concentrations
are elevated and chlorine is used for disinfection,
disinfection by-products (DBPs) such as
trihalomethanes, haloacetic acids, and NDMA can be
of concern. A more in-depth discussion of these
source water quality concerns is presented in
Prospects for Managed Underground Storage of
Recoverable Water and Reclaimed Water Aquifer
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Chapter 2 | Planning and Management Considerations
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 ug/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 USAGE 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,
2007 b).
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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
Arizona
Arizona
Florida
Florida
Florida
Florida
Florida
Florida
Florida
Florida
Florida
Florida
Florida
Florida
Florida
Texas
Australia
Australia
Kuwait
Chandler
Fountain Hills
Scottsdale
Cocoa
Englewood
Hillsborough County
Clearwater
Lehigh Acres
Manatee County
Collier County
Naples
Oldsmar
Pinellas County
St. Petersburg
Tarpon Springs
Sarasota County
El Paso
Adelaide (Bolivar)
Willunga
Sulaibiya
Full Operation
Full Operation
Full Operation
Testing
Full Operation
Terminated
Terminated
Testing
Testing
Testing
Testing
Permitting
Feasibility/Planning
Testing
Feasibility/Planning
Construction
Full Operation
Full Operation
Testing
Feasibility/Planning
Advanced treatment with UV disinfection
Conventional secondary treatment
/microfiltration/unknown method of disinfection
Advanced treatment/microfiltration/RO/CI2
disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
NA
NA
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment/ozone disinfection
Advanced treatment with CI2 disinfection
Advanced treatment with CI2 disinfection
Advanced treatment/RO/unknown method of
disinfection
(Source: Updated data from WRRF, 2007b)
CI2 means chlorine
NA means not applicable
2.3.3.5 Supplementing Reclaimed Water
Supplies
Another option to maximize the use of reclaimed water
for irrigation is to supplement reclaimed water flows
with other sources, such as groundwater or surface
water. Supplemental sources, where permitted, can
bridge the gap during periods when reclaimed water
flows are not sufficient to meet the demands,
Supplementing reclaimed water flows allows
connection of additional users and increases reuse
overall versus disposing of excess reclaimed water.
Incremental use of supplemental supplies can result in
a significant return in terms of reclaimed water usage
versus supplemental volumes.
An example of a utility that developed supplemental
supplies is the city of Cape Coral, Fla. There are
approximately 400 mi of canal systems within the city.
Of these, approximately 295 mi are considered
freshwater and about 105 mi are brackish water. In
addition, within these canals, approximately 27 water-
control 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
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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
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Chapter 2 | Planning and Management Considerations
potable reuse. Where reclaimed water is to be used in
nonpotable applications, water quality must be
protective of public health, but need not be treated to
the quality required for potable reuse. In addition to
appropriate water quality requirements, other
safeguards must be employed to protect public health
in nonpotable reuse.
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 cross-
connection 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.
IRRIGATED WITH
RECLAIMED WATER
Figure 2-7
Typical sign complying with FDEP signage
requirements (Photo credit: Lisa Prieto)
The type of messaging on advisory signs must comply
with state guidelines and regulations and be chosen
carefully to support public awareness. Chapter 8
discusses some of the issues surrounding messaging
about water reuse. One specific issue for signage that
includes the message "do not drink" is the potential
long-term public perception that reclaimed water
cannot be safe for drinking. If a city may want to
introduce potable reuse in the future, the choice of
messaging for signage of nonpotable reuse
applications is all the more critical.
In addition to advisory signs and coloring, the valve
covers for nonpotable transmission lines should not be
interchangeable with potable water covers. For
example, the city of Altamonte Springs, Fla., uses
square valve covers for reclaimed water and round
valve covers for potable water. Blow-off valves should
be painted and carry markings similar to other system
piping. Irrigation and other control devices should be
marked both inside and outside. Any constraints or
special instructions should be clearly noted and placed
in a suitable cabinet. If fire hydrants are part of the
system, they should be painted or marked, and the
stem should require a special wrench for opening.
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All piping, pipelines, valves, and outlets must be color-
coded, or otherwise marked, to differentiate reclaimed
water from domestic or other water (FDEP, 2009).
FDEP requires color coding with Pantone Purple 522C
using different methods, depending on the size of the
pipe (FDEP, 2009). Pipe coloring can be integrated
into the material or added externally with a
polyethylene vinyl wrap, vinyl adhesive tape, plastic
marking tape (with or without metallic tracer), or
stenciling, as shown in Figure 2-8. The IAPMO
publishes the Uniform Plumbing Code, a document
that many state and local governments use as a model
when they approve their own plumbing codes. An
alternate code is the IPC distributed by the ICC.
Figure 2-8
Reclaimed water pumping station, San Antonio,
Texas (Photo credit: Don Vandertulip)
Permitting and Inspection. The process to permit
water reclamation and reuse projects differs from state
to state; however, the basic procedures generally
include plan and field reviews followed by periodic
inspections of facilities. This oversight includes
inspection of reclaimed water generators, distributors
and, in some cases, end users. Additional guidance on
permitting and inspection is provided in the Manual of
Water Supply Practices M-24 (AWWA, 2009). Piping
at the site of reclaimed water use may be controlled by
local plumbing code, and advance coordination
between utility and local plumbing departments is
advised.
2.3.4.3 Preventing Improper Use and Backflow
Several methods can be used to prevent inadvertent
or unauthorized connection to a reclaimed water
system. The Irvine Ranch Water District, Calif.,
mandates the use of special quick-coupling valves with
an Acme thread key for on-site irrigation connections.
This type of valve is not used in potable water
systems, and the cover on the reclaimed water coupler
is different in color and material from that used on the
potable system. Hose bibs are generally not permitted
on nonpotable systems because of the potential for
incidental use and possible human contact with the
reclaimed water. Florida regulations (FDEP, 2009)
allow below-ground bibs that are either placed in a
locking box or require a special tool to operate.
Where the possibility of cross-connection between
potable and reclaimed water lines exists, backflow
prevention devices should be installed on-site when
both potable and reclaimed water services are
provided to a user. The backflow prevention device is
placed on the potable water service line to prevent
potential backflow from the reclaimed water system
into the potable water system if the two systems are
illegally interconnected. Accepted methods of backflow
prevention vary by state, but may include:
• Air gap
• Reduced-pressure principal backflow prevention
assembly
• Double-check valve assembly
• Pressure vacuum breaker
• Atmospheric vacuum breaker
In addition to discussion of backflow prevention in
Section 3.6.1 of the 2004 EPA Guidelines for Water
Reuse, additional guidance is provided in the 2003
EPA Cross-Connection Control Manual which has
been designed as a tool for health officials, waterworks
personnel, plumbers, and any others involved directly
or indirectly in water supply distribution systems, with
more recent information in the AWWA Manual of
Water Supply Practices M-24 (AWWA, 2009).
2.3.4.4 Maintenance
Maintenance requirements for nonpotable components
of the reclaimed water distribution system should be
the same as for potable systems. From the outset,
items such as isolation valves, which allow for repair to
parts of the system without affecting a large area,
should be designed into the system. Flushing the line
after construction should be mandatory to prevent
sediment from accumulating, hardening, and
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Chapter 2 | Planning and Management Considerations
becoming a serious future maintenance problem. New
systems should confirm whether discharge of
reclaimed water from the initial construction activity is
allowed or considered an unauthorized discharge. The
flush water may need to be returned to a sanitary
sewer, or use of potable water may be considered for
initial flushing. A reclaimed water supplier should
reserve the right to withdraw service for any offending
condition, subject to correction of the problem. Such
rights are often established as part of a user
agreement or reuse ordinance.
2.3.4.5 Quality Assurance: Monitoring
Programs
The purpose of monitoring is to demonstrate that the
management system and treatment train are
functioning according to design and operating
expectations. Expectations should be specified in
management systems, such as a Hazard Analysis and
Critical Control Points (HACCP) or water safety plan
(WSP). While the monitoring program will be based on
the regulatory and permit requirements established for
the system, the program not only must address those
elements needed to verify the product water but also
must support overall production efficiency and
effectiveness. Having performance standards and
metrics along with policies describing organizational
goals and responsibilities for the execution of a water
quality management program will reinforce a strong
public perception of the overall water quality being
produced. See Chapter 8 for additional discussion of
public education and communication tools.
Monitoring programs must establish goals for
reclaimed water treatment performance and
distribution system water quality, provide monitoring to
Table 2-4 Quality monitoring requirements in Texas
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 twice-
weekly monitoring protocol while Type II uses require
weekly monitoring.
Is human
Texas contact
Category likely?
Examples
CBOD5
Fecal Conforms or
Monitoring Enterococci Or E. coli BOD5 Turbidity
frequency (MPN/100mL) (MPN/100mL) (mg/L) (NTU)
Type I
Type II
Yes
No
Irrigation, recreational
impoundments,
firefighting, toilet flush
water
Restricted or remote
reuse
Twice weekly
Once weekly
9/41
35
75/201
800/2001
5
15or202
3
N/A
1 The first value represents a single sample maximum value and the next value refers to a 30-day average (BODS 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 BODS value is 20 mg/l for the same period.
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The first element of a system monitoring program is
choosing appropriate, quantifiable measurement
parameters that relate to operational and regulatory
decision-making. At a minimum, state-required
regulatory parameters should be included for analysis.
Parameters such as flow rates, distribution system
water quality (measured by chlorine residual and
bacteriological quality), and IDS 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 well-
accepted practices, such as Standard Methods for the
Examination of Water and Wastewater.
Because regulatory and public perception of the
monitoring program will rely heavily on the confidence
in the quality and validity of the data collected,
certifications or accreditations for laboratories doing
analytical work supporting the water industries may be
required. These can include state programs, such as
Arizona Department of Health Services (ADHS), or
national accreditation programs, such as The National
Environmental Laboratory Accreditation Conference
(NELAC) Institute (TNI, n.d.), which is used by states
like Texas and Florida. The NELAC Institute (TNI) was
formed in 2006 by combining the boards of the NELAC
and the Institute for National Environmental Laboratory
Accreditation. Accreditation may be required for both
internal and commercial laboratories. These programs
require laboratories that produce data to support water
quality programs to have established basic quality
requirements incorporated into their data collection
processes. These requirements should include the
analytical procedures, instrument calibration
requirements, quality control practices and
documentation, and reporting protocol sufficient to
document the traceability and quality of the result.
The city of Tucson, Ariz., has a well-established
Reclaimed Water Site Inspection Program that
accomplishes many of these goals [US-AZ-Tucson].
The program provides for periodic inspection of all
sites having reclaimed water service, along with
training and certification of reclaimed water site
testers.
2.3.4.6 Response to Failures
The final and probably most important element is a
well-defined and rigorously-enforced procedure for
responding to system failures within the defined
criteria. Obviously, this will include procedures for
returning to normal operation as quickly as reasonably
possible, but it should also include root-cause analysis
or other investigative techniques to determine if
systematic problems exist. In addition to water quality
monitoring, the system as a whole requires monitoring
and maintenance. A number of best practices to
monitor the system include:
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• Contractor training requirements on the
regulations governing reclaimed water
installations
• Requirements to submit all modifications to
approved facilities to the responsible agencies
• Detection and documentation of any breaks in
the transmission main
• Random inspections of user sites to detect any
faulty equipment or unauthorized use
• Installation of monitoring stations throughout the
system to test pressure, chlorine residual, and
other water quality parameters
• Accurate recording of system flow to confirm
total system use and spatial distribution of water
supplied
2.3.5 Lessons Learned from Large,
Medium, and Small Systems
Regardless of the size of a reclaimed water system,
there are lessons learned that can be applied to other
systems, and several case study examples are
highlighted below by system size. Large reclaimed
water systems (large systems) are defined as systems
with a capacity larger than 10 mgd (440 L/s). In
general, large systems have matured from smaller,
initial start-up or backbone facilities that were
implemented to meet smaller demands in prior years.
As illustrated by several current large systems in the
United States, however, this may not always be the
case. Medium reclaimed water systems (medium
systems) are defined as systems with a capacity
ranging from 1 to 10 mgd (44 to 440 L/s). And small
systems are defined as facilities treating flows ranging
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-VA-
Occoquan]. What emerged from regional planning are
key examples of planned I PR 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 USAGE wetlands
project in Arizona required public involvement and
public hearings through state and two federal agencies
[US-AZ-Phoenix]. San Antonio's project [US-TX-San
Antonio] was driven by endangered species lawsuits
limiting future water withdrawals, which required
multiple local, state, and federal agencies to work
together.
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Figure 2-9
Upper Occoquan schematic
Each of these projects is an example of leaders and
planners recognizing the importance of providing
timely and accurate information to decision-makers
and the public. These projects also provide valuable
resource recovery and reuse to support the local water
supply. In doing so, various permits required for the
projects were issued because of community support.
Medium Systems. Existing medium-sized facilities
can benefit from the experience of larger systems as
well as from the development of their existing systems.
Medium-sized systems have typically worked through
many of the same operational considerations and, in
most cases, the community is aware of the benefits of
reusing local resources. For medium systems in
particular, identifying potential reclaimed water
customers is one of the most important phases of
planning the reuse system and ensuring that the
system can be sustained. Unlike large systems with
capacities of greater than 10 mgd (438 L/s), which
generally have a set reclaimed water user baseline,
and smaller systems, which generally rely on a pre-
identified (and consistent) source of reclaimed water,
medium systems are largely dependent on the needs
of their customer bases. This need can greatly vary
depending on the type of reclaimed water customer,
the end use for the reclaimed water, and the time of
year (i.e., decreased demands in wet weather
months). Identifying potential customers will help
evaluate the financial viability of a reuse system as
well as provide an estimate of how much potable water
can be saved by connecting customers to a new
reclaimed water system. A more accurate estimate
may be provided by contacting identified potential
customers to determine their willingness to participate
in converting a portion of their demands to reclaimed
water.
An excellent case study example of a medium system
expanding its customer base is the city of Pompano
Beach, Fla. [US-FL-Pompano Beach]. The city's
OASIS (Our Alternative Supply Irrigation System)
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program is taking a systematic approach to increase
existing and future reuse capacity to achieve the
region's reuse requirements. Current plant capacity is
7.5 mgd (329 Us), 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 single-
family 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
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faced challenges, an intensive community outreach
program helped the city successfully expanded its
system into one of the first Class "A" Reclaimed Water
Facilities in the state of Washington. Yelm constructed
a wetlands park to have a highly visible and attractive
focal point promoting reclaimed water use, and a local
reclaimed water ordinance was adopted, establishing
the conditions of reclaimed water use. The ordinance
includes a "mandatory use" clause allowing Yelm to
require construction of reclaimed water distribution
facilities as a condition of development approval. Yelm
continues to plan expansion of storage, distribution,
and reuse facilities, and in 2002 the city received the
Washington State Department of Ecology's
Environmental Excellence Award for successfully
implementing Class "A" reclaimed water into its
community.
Additional information on low-cost treatment
technologies for small-scale water reuse projects is
provided in a recent WRRF report on Low-Cost
Treatment Technologies for Small-Scale Water
Reclamation Plants, which identifies and evaluates
established and innovative technologies that provide
treatment of flows of less than 1 mgd (44 L/s) (WRRF,
2012). A range of conventional treatment processes,
innovative treatment processes, and package systems
was evaluated with the primary value of this work
including an extensive cost database in which cost and
operation data from existing small-scale water
reclamation facilities have been gathered and
synthesized.
2.4 Water Supply Conservation and
Alternative Water Resources
Water scarcity is one of the key drivers for developing
reclaimed water supplies and systems. As part of the
overall management of water resources, it is critical to
evaluate alternative management strategies for
making the most of the existing supplies. Water
conservation is an important management
consideration for managing the water demand side.
On the supply side, the use of alternative water
resources, such as reuse of graywater, rainwater
harvesting (where applicable), produced water, and
other reuse practices, should also be considered as
part of an overall plan.
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
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• Time-of-day and day-of-week water limitations
• Seasonal limitations and/or rate structures
• High-efficiency device distribution and rebates
Since 1991, for example, the Los Angeles Department
of Water and Power has installed more than one
million ultra-low-flush toilets and hundreds of
thousands of low-flow showerheads and has provided
rebates for high-efficiency washing machines and
smart irrigation devices. The city used less water in
2010 than it did in 1990, despite adding more than
700,000 new residents to its service area (Rodrigo et
al., 2012).
While it is clear that potable water resources should be
conserved for the reasons above, reclaimed water in
some regions of the country is not considered a
resource; rather, it is sometimes viewed as a waste
that must be disposed of. With this mindset, customers
are sometimes encouraged to use as much reclaimed
water as they want, whenever they want. In areas
where there are fresh water supply shortfalls or where
reclaimed water has become valued as a commodity,
however, conservation has also become an important
element of reclaimed water management. As a result,
reclaimed water is recognized by many states as a
resource too valuable to be wasted. The 1995
Substitute Senate Bill 5605 Reclaimed Water Act,
passed in the state of Washington, stated that
reclaimed water is no longer considered wastewater
(Van Riper et al., 1998). The California legislature has
declared, "Recycled water is a valuable resource and
significant component of California's water supply"
(California State Water Resources Control Board,
2009). These recent declarations are part of broad
statewide objectives to achieve sustainable water
resource management. Chapter 8 describes how
water conservation and water reuse public outreach
can be synergistic.
Efficient and effective use can be critical to ensure that
the reclaimed water supply is available when there is a
demand for it. In addition, storage of reclaimed water
can focus on periods of low demand for later use
during high-demand periods, thereby stretching
available supplies of reclaimed water and maximizing
its use. While this practice is sometimes a challenge, it
is gaining interest because of recent advances in
management practices, such as ASR, which is
discussed in Section 2.3.
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
storm water.
2.4.2.1 Individual On-site Reuse Systems and
Graywater Reuse
Graywater is untreated wastewater, excluding toilet
and—in most cases—dishwasher and kitchen sink
wastewaters. Wastewater from the toilet and bidet is
"blackwater," and while the exclusion of toilet waste is
a key design factor in on-site and graywater systems,
this does not necessarily prevent fecal matter and
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other human waste from entering the graywater
system—albeit in small quantities. Examples of routes
for such contamination include shower water and
bathwater and washing machine discharge after
cleaning of soiled underwear and/or diapers (Sheikh,
2010). In fact, California's latest graywater standards
define graywater as untreated wastewater that has not
been contaminated by any toilet discharge; has not
been affected by infectious, contaminated, or
unhealthy bodily wastes; and does not present a threat
from contamination by unhealthful processing,
manufacturing, or operating wastes. Graywater does
include wastewater from bathtubs, showers, bathroom
washbasins, clothes washing machines, and laundry
tubs, but does not include wastewater from kitchen
sinks or dishwashers (California Building Standards
Commission, 2009). Thus, for a graywater system, it is
assumed that a building or homeowner would take
extraordinary care in source control of contaminants
and ensure pathogen-free graywater, an assumption
that could be questionable in a certain percentage of
cases.
For these reasons, use of graywater has been a
controversial practice. While viewed by some as the
panacea for water shortages, groundwater depletion,
surface water contamination, and climate change, use
of graywater can also be seen as a threat to the health
and safety of the users and their neighbors. While the
reality of graywater lies somewhere between these two
perceptions, the installation of a graywater system
may save a significant amount of potable water (and
its costs) for the homeowner or business, even though
the payback period for the more complex systems may
exceed the useful life of the system. Graywater use
does not always reduce total water use, as shown in a
study in Southern Nevada (Rimer, 2009). Because all
wastewater in the region is collected, treated, and
returned to Lake Mead, all water is already reused.
Using untreated or partially treated graywater had
higher public health risk than continued use of
reclaimed water, and graywater users felt less
constrained in using potable water, actually increasing
total metered water use. There are no documented
cases in the United States of any disease that has
been caused by exposure to graywater—although
systematic research on this public health issue is
virtually nonexistent. And, while the absence of
documentation does not prove that there has never
been such a case, graywater is, in fact, wastewater
with microbial concentrations far in excess of levels
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, 2011 a and
2011b). The standards provide detailed methods of
evaluation; product specifications; and criteria related
to materials, design and construction, product
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literature, wastewater treatment performance, and
effluent quality for on-site treatment systems.
Graywater treatment to NSF 350 levels also requires
certified operators, reliability, and public water supply
protection. The NSF/ANSI Standard 350 is for
graywater treatment systems with flows up to 1,500
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
CBOD6 (mg/L)
TSS (mg/L)
pH (SU)
Color
Odor
Oily film and foam
Energy consumption
25 mg/L
30 mg/L
6.0-9.0
MR1
Non-offensive
Non-detectable
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 On-
site 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
I Class R Class C
Parameter Test Average Maximum Test Average Maximum
CBOD6 (mg/L)
TSS (mg/L)
Turbidity (NTU)
E.coli'
(MPN/100mL)
pH (SU)
Storage vessel disinfection
(mg/L)3
Color
Odor
Oily film and foam
Energy consumption
10
10
5
14
6.0-9.0
>0.5-<2.5
MR4
Nonoffensive
Nondetectable
MR
25
30
10
240
NA'
NA
NA
NA
Nondetectable
NA
10
10
2
2.2
6.0-9.0
>0.5-<2.5
MR
Nonoffensive
Nondetectable
MR
25
30
5
200
NA
NA
NA
NA
Nondetectable
NA
NA: not applicable
Calculated as geometric mean
As total chlorine; other disinfectants can be used
MR: Measured reported only
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include suspended media treatment, fixed media
treatment systems, and constructed wetland systems.
All of these technologies must be followed by
advanced filtration and disinfection. On-site
applications of membrane bioreactor (MBR)
technology have also been utilized effectively in
commercial and residential properties for outdoor
irrigation and indoor nonpotable uses. Design
standards for treatment systems are enforced through
local health and environmental agencies, and permits
to operate on-site treatment systems often include
requirements for increased levels of monitoring.
Because increased monitoring can be burdensome for
small systems, operational monitoring can be used to
determine if the system is performing as expected. By
using instrumentation and remote monitoring
technologies, small schemes can produce real-time
data to ensure the system is functioning according to
water quality objectives. This operational monitoring
strategy is a risk management methodology borrowed
from the food and beverage industry; the HACCP is a
preventive approach that identifies points of risk
throughout the treatment process and assigns
corrective actions should data reveal heightened risk
(Natural Resource Management Ministerial Council,
Environment Protection and Heritage Council and
Australian Health Ministers' Conference, 2006). Water
quality parameters are set at different CCPs and
monitored in real-time online; if data reveal water
quality is outside the set parameters, a corrective
action will be triggered automatically in real time. With
an operational monitoring model in place, ongoing
sampling serves only as confirmation of the
operational data, and frequency of regulatory sampling
could be reduced. In the case where indoor uses are
allowed, turbidity meters are often employed as a
measure of system performance.
While the quantitative impact of increased graywater
use is expected to be modest, even under the most
aggressive growth assumptions, much of the growth in
graywater use is expected to take place in areas
where municipal water reuse will likely not be
practiced—unsewered urban areas and rural and
remote areas, as exemplified in several case studies
[Australia-Sydney]. Further, there are growing
possibilities for increased on-site treatment systems in
urban buildings that are LEED certified.
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) regional-
specific priority credits. Developments may qualify for
LEED certification designation and points, according to
the following qualified certification categories:
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LEED Certified - 40 to 49 points
• LEED Silver - 50 to 59 points
• LEED Gold - 60 to 79 points
• LEED Platinum - 80+ points
On-site treatment systems can comprise a substantial
fraction of the certification points with these systems
qualifying for up to a maximum number of 11 points
through the water efficiency and innovation and design
processes in combination with water conservation
practices. On-site water treatment systems may qualify
for up to 10 points in the water efficiency category
through water efficient design, construction, and long-
term 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.
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2.4.2.3 Stormwater Harvesting and Use
Comprehensive and sustainable integrated water
management programs should also consider multiple
goals, including those that are related to stormwater,
such as cost-effectively controlling flooding and
erosion; improving water quality; conserving,
sustaining, and recharging water supply; and
preserving and restoring the health of wetlands and
aquatic ecosystems. Because rainfall is generally the
most significant factor in managing stormwater,
capture and harvesting of rainfall and associated
runoff present opportunities for stormwater use
benefits. These include direct use of runoff for urban
and agricultural irrigation, alternative water supply,
aquifer recharge and saltwater intrusion barriers,
wetlands enhancement, low (minimum) flow
augmentation, feed lot cleaning, heating ventilation
and air conditioning (HVAC) and power plant cooling,
firefighting, and toilet flushing. However, stormwater
harvesting requires an effective means of stormwater
capture and retention that also supports the concurrent
need for flood control. A good example of this practice
is Cape Coral, Fla., which has maintained a very
effective stormwater harvesting program since the
1980s primarily because of its extensive network of
canals throughout the city. Within Cape Coral's
integrated water management system, stormwater
makes up as much as 75 percent of the irrigation
water demand in the city, which allows for 100 percent
reuse of the city's wastewater flows. Another case
study that highlights these benefits is from the Water
Purification Eco-Center (WPEC) at the Rodale Institute
in Kutztown, Pa. [US-PA-Kutztown]; the WPEC project
captures rainwater for public septic use and treats the
septic water to be returned to the surrounding
environment.
While the benefits of stormwater harvesting are clear,
there are currently no federal regulations governing
rainwater harvesting for nonpotable use, and the
policies and regulations enacted at the state and local
levels vary widely from one location to another.
Regulations are particularly fragmented with regard to
water conservation, as the permissible uses for
harvested water tend to vary depending on the climate
and reliability of the water supply. There are local
plumbing codes, and some states, including Georgia,
have published Rainwater Harvesting Guidelines, but
not all states have formally defined rainwater
harvesting as a practice distinct from water recycling
(Georgia Department of Community Affairs, 2009). In
recent years, cities and counties looking to promote
water conservation have begun issuing policies that
better define harvested water and its acceptable uses.
The city of Portland, Ore., for example, provides
explicit guidance on the accepted uses of harvested
water both indoors and outdoors. In January 2010, Los
Angeles County issued a policy providing a clear,
regulatory definition of "rainfall/nonpotable cistern
water" and drawing a specific distinction between
harvested water and graywater or recycled water.
In 2010, IAPMO published the Green Plumbing and
Mechanical Code Supplement (GPMCS). The
supplement is a separate document from the Uniform
Plumbing and Mechanical Codes and establishes
requirements for green building and water efficiency
applicable to plumbing and mechanical systems. The
purpose of the GPMCS is to "provide a set of
technically sound provisions that encourage
sustainable practices and works towards enhancing
the design and construction of plumbing and
mechanical systems that result in a positive long-term
environmental impact" (IAPMO, 2010). In addressing
"Non-potable Rainwater Catchment Systems," the
GPMCS specifically identifies provisions for collection
surfaces, storage structures, drainage, pipe labeling,
use of potable water as a back-up supply (provided by
air-gap only), and a wide array of other design and
construction criteria. It also refers to and incorporates
information from the ARCSA/ASPE Rainwater
Catchment Design and Installation Standard (2008), a
joint effort by the American Rainwater Catchment
Systems Association (ARCSA) and the American
Association of Plumbing Engineers (ASPE)
(ARCSA/ASPE, 2008).
2.5 Environmental Considerations
Increasing water withdrawals, coupled with effluent
discharges from WWTPs and agricultural runoff, can
dramatically alter the hydrological cycles and nutrient
cycling capacity of aquatic ecosystems. Water reuse
can have both positive and adverse impacts on
surrounding and downstream ecosystems. Elimination
or reduction of a surface water discharge by
reclamation and reuse generally reduces adverse
water quality impacts to the receiving water. However,
development of water reuse systems may have
unintended environmental impacts related to land use,
stream flow, and groundwater quality.
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Chapter 2 | Planning and Management Considerations
An environmental assessment may be required to
meet state regulations or local ordinances and is
required whenever federal funds are used. Formal
guidelines for the development of an environmental
impact statement (EIS) have been established by
EPA. Such studies are generally associated with
projects receiving federal funding or new NPDES
permits and are not specifically associated with reuse
programs. Where an investigation of environmental
impacts is required, it may be subject to state policies.
The following conditions could induce an EIS in a
federally-funded project:
• The project may significantly alter land use.
• The project is in conflict with land use plans or
policies.
• Wetlands will be adversely impacted.
• Endangered species or their habitat will be
affected.
• The project is expected to displace populations
or alter existing residential areas.
• The project may adversely affect a floodplain or
important farmlands.
• The project may adversely affect parklands,
preserves, or other public lands designated to
be of scenic, recreational, archaeological, or
historical value.
• The project may have a significant adverse
impact upon ambient air quality, noise levels, or
surface or groundwater quality or quantity.
• The project may have adverse impacts on water
supply, fish, shellfish, wildlife, and their actual
habitats.
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
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Chapter 2 | Planning and Management Considerations
runoff during a rainstorm. The instream system
bears the consequences of this change.
• Instream flow reduction is also possible and can
impact actual or perceived water rights. For
example, the Trinity River in Texas, near the
Dallas-Fort Worth Metroplex, maintains a
continuous flow of several hundred cubic feet
per second during dry periods due to return
flows (discharges) from multiple WWTPs. If
extensive reuse programs were to be
implemented at the upstream facilities, dry
weather flows in the Trinity River would be
reduced, and plans for urban development
downstream could potentially be impacted due
to water restriction. Houston-area interest near
the downstream end of the Trinity River stalled
TCEQ issuance of Metroplex discharge and bed
and banks transfer permits for several years
until agreements were reached with individual
large discharges in the Metroplex to maintain
minimum flow to Lake Livingston, a primary
source of drinking water for Houston.
In southern Arizona, the San Pedro River is distinct as
the last free-flowing undammed river in Arizona, which
supports a unique desert riparian ecosystem.
Population growth around Sierra Vista has caused a
significant drop in the groundwater table, which in turn
reduces the stream flow in the river. Ecological
considerations, including the protection of endangered
species, prompted the decision to recharge the
underlying aquifer with reclaimed water. Environmental
Operations Park (EOP) in Sierra Vista includes a
reclamation facility that polishes reclaimed water in
constructed wetlands. The reclaimed water is then
used to recharge the local aquifer in order to mitigate
the adverse impacts of continued groundwater
pumping in the San Pedro River system. The Sierra
Vista EOP was established as a multi-use center,
combining recharge basins, constructed wetlands,
native grasslands, and a wildlife viewing facility [US-
AZ-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-TX-
San 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
2012 Guidelines for Water Reuse
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Chapter 2 | Planning and Management Considerations
sensitive to certain constituents than humans (NRC,
2012).
In addition to potential impacts on surface water
quality, groundwater quality can be significantly
impacted by recharge with reclaimed water.
Recharging groundwater with reclaimed water may
change the water quality in the receiving aquifer.
Conditions must be evaluated on a case-by-case
basis, depending on potential constituents present in
reclaimed water and the underlying site hydrogeology;
additional discussion is provided in Section 2.3.3.
2.6 References
ARCSA/ASPE, 2008, Rainwater Catchment Design and
Installation Standard. Retrieved August 23, 2012 from
.
California Department of Public Health (CDPH). 2011. Draft
Regulations for Groundwater Replenishment with Recycled
Water. November 21, 2011. Retrieved August 2012, from
.
California State Water Resources Control Board (SWRCB).
2009. Recycled Water Policy. Retrieved July 2012, from
.
Entrix. 2010. "ASR Using Sodium Bisulfide Treatment for
Deoxidation to Prevent Arsenic Mobilization." Proceedings of
the Aquifer Recharge Conference. Orlando, FL.
Florida Department of Environmental Protection (FDEP). n.d.
Retrieved July 2012 from
.
Fox, P. 2002. 'Soil Aquifer Treatment: An Assessment of
Sustainability." In Management of Aquifer Recharge for
Sustainability. A. A. Balkema Publishers. Australia.
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Chapter 2 | Planning and Management Considerations
Georgia Department of Community Affairs. 2009. Georgia
Rainwater Harvesting Guidelines. Retrieved August 2012,
from
.
Gordon, H. B., L. D. Rotstayn, J. L. McGregor, M. R. Dix, E.
A. Kowalczyk, S. P. O'Farrell, L. J. Waterman, A. C. Hirst, S.
G. Wilson, M. A. Collier, I. G. Watterson, and T. I. Elliott.
2002. "The CSIRO Mk3 Climate System Model." In CSIRO
Atmospheric Research Technical Paper, no. 60.
Commonwealth Scientific and Industrial Research
Organisation. Australia.
Henry, R. 2011. "Lake Lanier Water Dispute: Court Won't
Rehear Ruling." Huffington Post. Retrieved August 2012,
from .
NSF/ANSI 350-2011 (NSF). 2011 a. Onsite Residential and
Commercial Water Reuse Treatment Systems. National
Sanitation Foundation, Ann Arbor, Michigan, July 2011.
NSF/ANSI 350-1-2011 (NSF) 2011b. Onsite Resident/aland
Commercial Graywater Treatment Systems for Subsurface
Discharge. National Sanitation Foundation, Ann Arbor,
Michigan, June 2011.
National Water Commission of Mexico. 2010. Statistics on
Water in Mexico. CONAGUA. Mexico.
Natural Resource Management Ministerial Council,
Environment Protection and Heritage Council, and Australian
Health Ministers' Conference. 2006. Australian Guidelines
for Water Recycling: Managing Health and Environmental
Risks. Environment Protection Heritage Council. Canberra,
Australia.
Oasis Design. 2012. Graywater Policy Center. Retrieved
July 2012 from .
O'Connor, T. P., D. Rodrigo, and A. Cannan. 2010. "Total
Water Management: The New Paradigm for Urban Water
Resources Planning." Proceedings of World Environmental
and Water Resources Congress 2010. Providence, R.I.
Pyne, R. D. G. 2005. Aquifer Storage Recovery: A Guide to
Groundwater Recharge through Wells. 2nd edition. ASR
Systems Publishing, Gainsville, FL.
Rimer, A. 2009. 'Graywater 'Blues' - The Perils of Its Use."
WateReuse Symposium, Seattle, WA.
Rodrigo, D., E. J. Lopez Calva, and A. Cannan. 2012. Total
Water Management. EPA 600/R-12/551. U.S. Environmental
Protection Agency. Washington, D.C.
Rose, J. B., D. E. Huffman, K. Riley, S. Farrah, J. Lukasik,
and C. L. Hamann. (2001). "Reduction of Enteric
Microorganisms at the Upper Occoquan Sewage Authority
Water Reclamation Plant." Water Environment Research.
73:711-720.
San Antonio Water System (SAWS). 2006. Recycled Water
Users' Handbook. Retrieved July 2012 from
Sheikh, B. 2010. White Paper on Graywater. WateReuse
Association. Alexandria, VA.
2012 Guidelines for Water Reuse
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Chapter 2 | Planning and Management Considerations
Shrier, C. 2010. "Reclaimed Water ASR for Potable Re-Use:
The Next Frontier." Proceedings of the Aquifer Recharge
Conference. Orlando, FL.
Stuyfzand, P. J. 1998. "Quality Changes upon Injection into
Anoxic Aquifers in the Netherlands: Evaluation of 11
Experiments." In J. H. Peters (Ed.), Artificial Recharge of
Groundwater. A.A. Balkema. Rotterdam, Netherlands.
Texas Commission on Environmental Quality (TCEQ). 1997.
Texas Administrative Code. Retrieved August, 2012, from
.
Toze, S., and J. Hanna. 2002. "The Survival Potential of
Enteric Microbial Pathogens in a Treated Effluent ASR
Project." In Management of Aquifer Recharge for
Sustainability. Balkema Publishers. Australia.
U.S. Environmental Protection Agency (EPA). 2012.
WaterSense: An EPA Partnership Program. Retrieved
September 6, 2012 from .
U.S. Environmental Protection Agency (EPA). 2006. Process
Design Manual Land Treatment of Municipal Wastewater
Effluents. EPA/625/R-06/016. Environmental Protection
Agency, Office of Research and Development. Cincinnati,
OH.
U.S. Environmental Protection Agency (EPA). 2004.
Guidelines for Water Reuse. EPA. 625/R04/108.
Environmental Protection Agency. Washington, D.C.
U.S. Environmental Protection Agency (EPA). 2003. Cross-
Connection Control Manual. EPA 816-R-03-002.
Environmental Protection Agency, Office of Water,
Washington, D.C.
U.S. Environmental Protection Agency (EPA). 2001. Safe
Drinking Water Act, Underground Injection Control (UIC)
Program, Protecting Public Health and Drinking Water
Resources. EPA. 816-H-01-003. Environmental Protection
Agency. Washington, D.C.
U.S. Environmental Protection Agency (EPA). 1974. Design
Criteria for Mechanical, Electrical, and Fluid System and
Component Reliability - Supplement to Federal Guidelines
for Design, Operation, and Maintenance of Waste Water
Treatment Facilities. EPA 430/99-74-001. Environmental
Protection Agency. Washington, D.C.
U.S. Green Building Council (USGBC). n.d. Accessed July
2012 from .
Van Riper, C., G. Schlender, and M. Walther. 1998.
"Evolution of Water Reuse Regulations in Washington
State." WateReuse Conference Proceedings. Denver, CO.
Vandertulip, W. D. 2011 a. "Are We Color Blind?" WEFTEC
Proceedings. Los Angeles, CA.
Vandertulip, W. D. 2011b. "Can We Support a National
Water Utility Pipe Color Code?" WateReuse Symposium
Proceeding. Phoenix, AZ.
WateReuse Association (WRA). 2009. Manual of Practice,
How to Develop a Water Reuse Program. WateReuse
Association. Alexandria, VA.
Water Environment Research Foundation (WERF). n.d.
Case Study: Battery Park Urban Water Reuse. Water
Environment Research Foundation. Alexandria, VA.
WateReuse Research Foundation (WRRF). 2009. Selection
and Testing of Tracers for Measuring Travel Times in
Natural Systems Augmented with Treated Wastewater
Effluent. WRF-05-007. WateReuse Research Foundation.
Alexandria, VA.
WateReuse Research Foundation (WRRF). 2007a.
Extending the Integrated Resource Planning Process to
Include Water Reuse and Other Nontraditional Water
Sources. WRF-04-010. WateReuse Research Foundation.
Alexandria, VA.
WateReuse Research Foundation (WRRF). 2007b.
Reclaimed Water Aquifer Storage and Recovery: Potential
Changes in Water Quality. WRF-03-009-01. WateReuse
Foundation. Alexandria, VA.
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CHAPTER 3
Types of Reuse Applications
The United States has achieved numerous
accomplishments toward expanding the use of
reclaimed water and extending water resources for
many communities. Yet, there is room for improvement
in terms of the total amount of water reused,
distribution of reclaimed water use throughout the
country, and the adoption of new, higher quality uses.
A report by the NRC Water Science & Technology
Board titled Water Reuse: Potential for Expanding the
Nation's Water Supply Through Reuse of Municipal
Wastewater estimates that as much as 12 bgd (45
MCM/d) of the 32 bgd (121 MCM/d) produced in the
United States can be beneficially reclaimed and
reused (NRC, 2012). Recent estimates indicate that
approximately 7 to 8 percent of wastewater is reused
in the United States (Miller, 2006 and GWI, 2009)
(Figure 3-1). Therefore, there is tremendous potential
for expanding the use of reclaimed water in the future.
Approximately 7-8%
reclaimed
The United States produces approximately 32
billion gallons of municipal effluent per day.
Figure 3-1
Reclaimed water use in the United States
Outside of the United States, there are examples of
countries with different water resource demands that
greatly exceed this percentage. Several countries,
including Australia and Singapore, have established
goals for reuse, expressed in terms of the percentage
of municipal wastewater effluent that is treated to a
higher quality and beneficially reused. Australia
currently reuses approximately 8 percent of its treated
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 Mid-
Atlantic and Northeast regions of the United States,
with a number of water reuse facilities in New Jersey,
Pennsylvania, New York, and Massachusetts.
Production and distribution of reclaimed water varies
regionally by categories of use and depends on
historical and emerging drivers, as described in
Chapter 5.
Table 3-1 shows the distribution of reclaimed water
use for California and Florida—the two largest users of
reclaimed water in the United States. Although
California reused 669,000 ac-ft (825 MCM) of water in
2009, coastal communities were an untapped source
of reclaimed water by discharging 3.5 million ac-ft
(4,300 MCM) of highly-treated wastewater to the
Pacific Ocean. The challenge for coastal communities
then shifts from adequate supply to an ability to
distribute the new source water from the coast through
a highly-developed urbanized area to points of use.
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Chapter 3 | Types of Reuse Applications
Table 3-1 Distribution of reclaimed water in California (Baydal, 2009) and Florida (FDEP, 2011)
Reuse Category (% SSSos)
Irrigation
Agricultural
Urban reuse (landscape irrigation, golf courses)
Groundwater Recharge
Seawater Intrusion Barrier
Industrial Reuse
Natural Systems and Other Uses
Recreational Impoundments
Geotherma
Energy
29
19
5
8
7
23
7
2
Florida
(% Use in 2010)
11
55
14
-
13
9
-
-
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.
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Chapter 3 Types of Reuse Applications
A more recent survey in 2006 by the GCSAA and the
Environmental Institute for Golf (EIFG) requested input
from superintendents at 16,797 courses and received
response from 2,548 (GCSSA and EIFG, 2009).
Based on this survey, an estimated 12 percent of golf
courses in the United States use reclaimed water, with
more courses in the southwest (37 percent) and
southeast (24 percent) practicing reuse. In fact, the
most recent state survey for Florida in 2010 (FDEP,
2011) listed 525 golf courses using nearly 118 mgd
(5170 L/s) of reclaimed water, representing about 17.9
percent of the daily reuse within the state. This
continued application of reuse to golf courses is
exemplified in the following case studies:
• US-FL-Pompano Beach
• US-FL-Marco Island
• US-TX-Landscape Study
• Australia-Victoria
The most common reason identified by golf courses
for not using reclaimed water for irrigation was the lack
of a source for reclaimed water (53 percent of
respondents) (FDEP, 2011). It was also not a surprise
that the poorest water quality identified by respondents
was in the southwest where there was typically higher
TDS and salinity concerns. With lower water quality,
systems in the southwest and southeast were most
likely to use wetting agents and fertigation systems. To
address some of the water quality concerns, turfgrass
research has been conducted to determine the most
salt-tolerant species for a geographic area and soil
type.
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
Degree of Restriction on Use
Slight to
Parameter Units None Moderate Severe
Salinity
Ecw
TDS
Ion Toxicity
Sodium (Na)
Root Absorption
Foliar Absorption
Chloride (Cl)
Root Absorption
Foliar Absorption
Boron
PH
dS m '
mq/L
SAR
meq/L
mq/L
meq/L
mq/L
meq/L
mq/L
mq/L
<0.7
< 450
< 3
< 3
<70
< 2
< 70
< 3
< 100
<1.0
0.7- 3.0
450 - 2,000
3-9
> 3
>70
2- 10
70 - 355
> 3
> 100
1.0-2.0
6.5-8.4
> 3.0
> 2,000
>9
> 10
> 355
>2.0
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Chapter 3 | Types of Reuse Applications
• Modifying turf management practices
• Modifying the root zone mixture
• Blending irrigation waters
• Using amendments
A study by Virginia Polytechnic Institute and State
University investigated nutrient management practices
and application rates of nitrogen to turf and crops in
Virginia (Hall et al., 2009). This study found that 50
percent of responding golf course superintendents
were applying nitrogen to greens at rates in excess of
turfgrass needs (> 5.1 Ibs 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 long-
term 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.
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• 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
etal., 2011)
I Annual Agricultural Reuse
State mgd 1000 ac-ft/yr
Arizona
California
Colorado
Florida
Idaho
North Carolina
Nevada
Texas
Utah
Washington
Wyoming
23
270
2.97
256
0.27
1.0
13.4
19.4
0.81
0.02
0.89
26
303
3
287
0.3
1
15
22
1
0.03
1
4% 2%
7%
18%
20%
i Agriculture Irrigation: 29%
i Other: 20%
Landscape Irrigation/Golf Course Irrigation: 18%
i Seawater Barrier: 8%
Commercial & Industrial: 7%
i 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)
Figure 3-2
Nationwide reuse summaries of reclaimed water use in agricultural irrigation (adapted from Bryk, etal., 2011)
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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 disease-
carrying 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, well-
drained 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
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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 I Slight to Moderate I Severe
Salinity (affects crop water availability)''
ECW
TDS
dS/m
mg/L
<0.7
<450
0.7-3.0
450 - 2000
>3.0
>2000
Infiltration (affects infiltration rate of water into the soil; evaluate using ECW and SAR together)3
SAR
0-3
3-6
6-12
12-20
20-40
and ECW =
>0.7
>1.2
> 1.9
> 2.9
>5.0
0.7-0.2
1.2-0.3
1.9-0.5
2.9-1.3
5.0-2.9
<0.2
<0.3
<0.5
< 1.3
<2.9
Specific Ion Toxicity (affects sensitive crops)
Sodium (Na)4
surface irrigation
sprinkler irrigation
Chloride (Cl)4
surface irrigation
sprinkler irrigation
Boron (B)
SAR
meq/l
meq/l
meq/l
mg/L
< 3
< 3
< 4
< 3
<0.7
3-9
>3
4-10
> 3
0.7-3.0
Miscellaneous Effects (affects susceptible crops)
Nitrate (NO3-N)
Bicarbonate (HCO3)
PH
mg/L
meq/L
<5
< 1.5
5-30
1.5-8.5
>9
> 10
> 3.0
>30
>8.5
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.
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• Restriction on Use: The "Restriction on Use"
shown in Table 3-4 is divided into three degrees
of severity: none, slight to moderate, and
severe. The divisions are somewhat arbitrary
because changes occur gradually, and there is
no clear-cut breaking point. A change of 10 to
20 percent above or below a guideline value
has little significance if considered in proper
perspective with other factors affecting yield.
Field studies, research trials, and observations
have led to these divisions, but management
skill of the water user can alter the way in which
the divisions are interpreted for a particular
application. Values shown are applicable under
normal field conditions prevailing in most
irrigated areas in the arid and semi-arid regions
of the world.
3.2.2.1 Salinity and Chlorine Residual
As noted in Table 3-4, salinity is a key parameter in
determining the suitability of the water to be used for
irrigation, and the wide variability of salinity tolerance
in plants can confound the issue of establishing salinity
criteria. All waters used for irrigation contain salt to
some degree; therefore, salts (both cations and
anions) will build up without proper drainage.
Agricultural Salinity Assessment and Management,
which is the second edition of ASCE MOP 71
(American Society of Civil Engineers [ASCE], 2012)
provides additional information on worldwide salinity
and trace element management in irrigated agriculture
and water supplies. This updated edition provides a
reference to help sustain irrigated agriculture and
integrates contemporary concepts and management
practices. It covers technical and scientific aspects of
agricultural salinity management as well as
environmental, economic, and legal concerns.
However, because salinity management is such an
important consideration in agricultural reuse, a brief
discussion of the topic is provided here.
Salinity is determined by measuring the electrical
conductivity (EC) and/or the TDS in the water;
however, for most agricultural measurements, TDS is
reported as EC. The use of high TDS water for
irrigation will tend to increase the salinity of the
groundwater if not properly managed. The extent of
salt accumulation in the soil depends on the
concentration of salts in the irrigation water and the
rate at which salts are removed by leaching. Using
TDS as a measure of salinity, no detrimental effects
are usually noticed below 500 mg/L. Between 500 and
1,000 mg/L, TDS in irrigation water can affect sensitive
plants; at concentrations above 1,000 to 2,000 mg/L,
TDS levels can affect many crops, so careful
management practices should be followed. Several
case study examples demonstrate the importance and
implementation of TDS management for use of
reclaimed water for irrigation [US-TX-Landscape
Study; US-CO-Denver Soil; US-CA-Monterey; and
Israel/Jordan-AWT Crop Irrigation]. At TDS
concentrations greater than 2,000 mg/L, water can be
used regularly only for salt-tolerant plants on highly
permeable soils. A study was conducted in Israel to
address the impact of reclaimed water containing high
levels of salts, including ions specifically toxic to
plants, such as sodium (Na) and boron (B); results are
provided in a case study summary from Israel and
Jordan [Israel and Jordan - Brackish Irrigation].
With respect to chlorine residuals, which may be
present as a disinfection residual, free chlorine at
concentrations less than 1 mg/L usually poses no
problem to plants; chlorine at concentrations greater
than 5 mg/L can cause severe damage to most plants.
However, some sensitive crops may be damaged at
levels as low as 0.05 mg/L. For example, some woody
crops may accumulate chlorine in the tissue up to toxic
levels; further, excessive chlorine residuals can have a
similar leaf-burning effect that is caused by sodium
and chloride when reclaimed water is sprayed directly
onto foliage. Low-angle spray heads or surface
irrigation options can reduce the leaf-burning impact.
3.2.2.2 Trace Elements and Nutrients
Thirteen mineral nutrients are required for plant
growth, and fertilizers are added to soils with
inadequate concentrations of these nutrients. Mineral
nutrients are divided into two groups: macronutrients
(primary and secondary) and micronutrients. Primary
macronutrients, which include nitrogen, phosphorus,
and potassium, are often lacking from the soil because
plants use large amounts for growth and survival. The
secondary macronutrients include calcium,
magnesium, and sulfur. Micronutrients—boron,
copper, iron, chloride, manganese, molybdenum, and
zinc—are elements essential for plant growth in small
quantities and are often referred to as trace elements.
While these trace elements are necessary for plant
growth, excessive concentrations can be toxic.
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The recommended maximum concentrations of
constituents in reclaimed water for "long-term
continuous use on all soils" are set conservatively
based on application to sandy soils that have
adsorption capacity. These values have been
established below the concentrations that produce
toxicity when the most sensitive plants are grown in
nutrient solutions or sand cultures to which the
constituent has been added. Thus, if the suggested
limit is exceeded, phytotoxicity will not necessarily
occur; however, most of the elements are readily fixed
or tied up in soil and accumulate with time such that
repeated application in excess of suggested levels is
likely to induce phytotoxicity. The trace element and
nutrients criteria recommended for fine-textured
neutral and alkaline soils with high capacities to
remove the different pollutant elements are provided in
Table 3-5. These criteria, were previously presented in
2004, however, based on maintaining sustainable
application of reclaimed water for irrigation,
recommendations have included removal of increased
concentrations for short-term use, which is also
consistent with recommendations of the FAO in Water
Quality for Agriculture (FAO, 1985). There are also
related effects of pH on plant growth, which are
primarily related to its influence on metal toxicity, as
shown in Table 3-5; as a result, a pH range of 6-8 is
recommended for reclaimed water used for irrigation.
Of the macronutrients, nitrogen is the most widely
applied as a fertilizer. Nitrogen is important in helping
plants with rapid growth, increasing seed and fruit
production, and improving the quality of leaf and
forage crops. Like nitrogen, phosphorus effects rapid
Table 3-5 Recommended water quality criteria for irrigation
Maximum
for Irrigation
Constituent (mg/L)
Aluminum
Arsenic
Beryllium
Boron
Cadmium
Chromium
Cobalt
Copper
Fluoride
Iron
Lead
Lithium
Manganese
Molybdenum
Nickel
Selenium
Tin, Tungsten,
and Titanium
Vanadium
Zinc
5.0
0.10
0.10
0.75
0.01
0.1
0.05
0.2
1.0
5.0
5.0
2.5
0.2
0.01
0.2
0.02
-
0.1
2.0
Can cause nonproductiveness in acid soils, but soils at pH 5.5 to 8.0 will precipitate
the ion and eliminate toxicity
Toxicity to plants varies widely, ranging from 12 mg/L for Sudan grass to less than
0.05 mg/L for rice
Toxicity to plants varies widely, ranging from 5 mg/L for kale to 0.5 mg/L for bush
beans
Essential to plant growth; sufficient quantities in reclaimed water to correct soil
deficiencies. Optimum yields obtained at few-tenths mg/L; toxic to sensitive plants
(e.g., citrus) at 1 mg/L. Most grasses are tolerant at 2.0 - 10 mg/L
Toxic to beans, beets, and turnips at concentrations as low as 0.1 mg/L; conservative
limits are recommended
Not generally recognized as an essential element; due to lack of toxicity data,
conservative limits are recommended
Toxic to tomatoes at 0.1 mg/L; tends to be inactivated by neutral and alkaline soils
Toxic to a number of plants at 0.1 to 1 .0 mg/L
Inactivated by neutral and alkaline soils
Not toxic in aerated soils, but can contribute to soil acidification and loss of
phosphorus and molybdenum
Can inhibit plant cell growth at very high concentrations
Tolerated by most crops up to 5 mg/L; mobile in soil. Toxic to citrus at low doses —
recommended limit is 0.075 mg/L
Toxic to a number of crops at few-tenths to few mg/L in acidic soils
Nontoxic to plants; can be toxic to livestock if forage is grown in soils with high
molybdenum
Toxic to a number of plants at 0.5 to 1.0 mg/L; reduced toxicity at neutral or alkaline
PH
Toxic to plants at low concentrations and to livestock if forage is grown in soils with
low levels of selenium
Excluded by plants; specific tolerance levels unknown
Toxic to many plants at relatively low concentrations
Toxic to many plants at widely varying concentrations; reduced toxicity at increased
pH (6 or above) and in fine-textured or organic soils
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growth of plants and is important for blooming and root
growth. Potassium is absorbed by plants in larger
amounts than any other mineral element except
nitrogen and, in some cases, calcium; the role of this
nutrient is key in fruit quality and reduction of diseases.
All of these nutrients can be obtained from application
of reclaimed water, so there is added value in using
reclaimed water. However, in light of ever-increasing
regulatory requirements for nutrient removal to
address loads to receiving streams, nitrogen and/or
phosphorus are often removed in municipal WWTPs.
As a result of nutrient removal, even if reclaimed water
is applied in adequate quantities to provide trace
nutrients, fertilizer application may still be required.
Where appropriate for crop use, increased supply of
reclaimed water for irrigation could provide needed
nutrients for crops while concurrently reducing nutrient
load to the receiving stream.
Nutrients, such as nitrogen and phosphorus, may
contain beneficial qualities for irrigation. In a Canadian
case study, the authors provided insight into cost-
effective 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
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gastrointestinal disease consequences for consumers
of the crops. As a result, the WHO guidelines provide
specific procedures for minimizing these risks in most
regions of the world (WHO, 2006). These regulations
for food crop irrigation with reclaimed water are
intended to minimize risks of microbial contamination
of the crops, especially those grown for raw
consumption, such as lettuce, cucumbers, and various
fruits. The regulations specify treatment processes,
water quality standards, and monitoring regimes that
minimize risks for use of reclaimed water for irrigation
of crops that are ingested by humans. Further
discussion on global water reuse is provided in
Chapter 9. Additional discussion of state regulatory
guidelines and requirements for irrigation of food crops
with reclaimed water is also provided in Section
4.5.2.3.
An example of large-scale recycled water irrigation for
raw-eaten food crops is in Monterey County, Calif.
[US-CA-Monterey]. More than 5,000 ha of lettuce,
broccoli, cauliflower, fennel, celery, strawberries, and
artichokes have been irrigated with recycled water for
more than a decade (Figure 3-3). This large-scale use
of recycled water was preceded by an intensive, 11-
year pilot study to determine whether or not the use of
disinfected filtered recycled water for irrigation of raw-
eaten 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 well-
operated secondary treatment processes with
disinfection.
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Figure 3-3
Monterey County vegetable fields irrigated with disinfected tertiary recycled water
Figure 3-4
Alfalfa irrigated with secondary effluent, Wadi Mousa (near Petra), Jordan
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Between the standards of California and WHO, there
is a wide range of treatment standards throughout the
world, as shown in Table 3-6. Additional discussion of
state regulatory guidelines and requirements for
irrigation of food crops with reclaimed water in the
United States is also provided in Section 4.5.2.3.
Table 3-6 Examples of global water quality standards
for non-food crop irrigation
Fecal
Coliform
Guidelines by
State, Country, Region
oliform E. coliper
per 100 mL 100 mL
Puglia (S. Italia)
California, Italy
Australia
Germany
Washington State
Florida, Utah, Texas, EPA
(Guidelines)
Arizona, New Mexico,
Australia, Victoria, Mexico
Austria
Sicily
Cyprus
WHO, Greece, Spain
<10
<23
<100
<240
< 3,000
<10
<10
<200
< 1,000
< 2,000
< 1,000
< 3,000
< 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,
ate 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)
Aluminium (Al)
Arsenic (As)
Beryllium (Be)^
Boron (B)
Cadmium (Cd)
Chromium (Cr)
Cobalt (Co)
Copper (Cu)
Fluoride (F)
Iron (Fe)
Lead (Pb)J
Manganese (Mn)4
Mercury (Hg)
Molybdenum (Mo)
Nitrate + Nitrite (NO3-N + NO2-N)
Nitrite (NO2-N)
Selenium (Se)
Sodium (Na)
Sulfate (as SO4)
Vanadium (V)
Zinc (Zn)
Concentration
(mg/L)
5.0
0.2
0.1
5.0
0.05
1.0
1.0
0.5
2.0
not needed
0.1
0.05
0.01
0.3
100
10.0
0.05
10005
1000b
0.10
24.0
Adapted from FAO (1985) with updates for Mo, Na,
and SO4 from Raisbeck et al. (2011).
Insufficient data for livestock; value for marine aguatic
life is used.
Lead is accumulative, and problems may begin at a
threshold value of 0.05 mg/L.
Insufficient data for livestock; value for human drinking
water used.
Short-term exposure (days/weeks) can be up to 4000
mg/L, assuming normal feedstuff Na concentrations.
Short-term exposure (days/weeks) can be up to 1.8
mg/L, assuming normal feedstuff SO4 concentrations.
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3.3.1 Recreational and Landscape
Impoundments
One example of reclaimed water use for recreational
impoundments is the Santee Lakes Recreation
Preserve (Park), which is a recreational facility owned
and operated by Padre Dam Municipal Water District.
It is located strategically within San Diego County,
Calif. Its seven lakes, which contain approximately 82
ac (33 ha) of water, were formed by sand and gravel
mining in the dry stream bed of Sycamore Canyon as
part of the district's original water reclamation
program. In the early 1960s, the district converted the
lakes to recreational use to demonstrate the concept
of water reuse. Its purpose was also to gain public
acceptance of reclaimed water for recreational,
agricultural, irrigation, and industrial applications.
As with any form of reuse, the development of water
reuse projects that include impoundments will be a
function of water demand coupled with a cost-effective
source of suitable quality reclaimed water. Regulation
of impoundments that are maintained using reclaimed
water typically is according to the potential for contact
for that use. For example, in Arizona, reclaimed water
that is used for recreational impoundments where
boating or fishing is an intended use of the
impoundment must meet Class A requirements, which
includes secondary treatment, filtration, and
disinfection so that no detectable fecal coliform
organisms are present in four of the last seven daily
reclaimed water samples taken, and no single sample
maximum concentration of fecal coliform organisms
exceeds 23/100 ml_. Even though NPDES permits
may allow discharge of treated effluent into a water
body with higher bacterial concentrations, swimming
and other full-body recreation activities are prohibited
where reclaimed water is used to maintain the
"recreational" impoundment. This is consistent with
goals to protect public health, particularly in light of
evidence provided by Wade et al. (2010) who have
shown a relationship between gastrointestinal illness
and estimates of fecal indicator organisms and that
children less than 11 years old are at greater risk from
exposure (Wade et al., 2008).
In impoundments where body contact is prohibited,
such as a manmade facility that is created for storage,
landscaping, or for aesthetic purposes only, less
stringent requirements may apply.
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-ME-
Snow]. Some states have rules or regulations
pertaining to snowmaking with reclaimed water. There
do not appear to be any human health effects studies
associated with exposure to snow made with
reclaimed water. The highlights of the regulations from
a few select states are provided to exemplify how
different states implement snowmaking with reclaimed
water.
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Storing or stockpiling reclaimed water in the form of
snow avoids the cost of building large surface water
reservoirs or additional lagoon treatment modules.
Depending on the quality of the originating reclaimed
water, precautions may need to be taken regarding the
fate of snowmelt. It may be necessary to prevent
snowmelt from frozen reclaimed water with a relatively
high content of phosphorus from entering a sensitive
water body. Conversely, if reclaimed water can be
sprayed onto a seasonally dormant agricultural field,
the phosphorus may be a benefit to the farmer who will
plant the field in the spring.
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 three-
judge 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
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of the Continental Divide, reclaimed water is first
applied to highest use at lowest cost.
Maine
The Maine Department of Environmental Protection
(MDEP) does not have reclaimed water quality or
water reuse rules, let alone regulations for
snowmaking. However, the MDEP issues wastewater
discharge permits for making snow with reclaimed
water under the Maine Pollution Discharge Elimination
System program. Snowmaking is used to reduce the
volume of water in lagoons or to otherwise manage
treatment plant effluent. There are currently systems in
operation in three Maine communities (town of
Rangeley; Carrabassett Valley Sanitary District, which
serves Sugarloaf Mountain Ski Resort; and Mapleton
Sewer District).
New Hampshire
New Hampshire's rules regarding snowmaking provide
more discussion about snowmaking than any other
state. Snow can be made using disinfected, filtered
secondary effluent, depending on the end use of the
manufactured snow. It can be used to recharge
aquifers or for recreation purposes, such as skiing.
Snow made from reclaimed water is referenced as "E-
Snow" (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.
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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 Us), 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 vertical-
flow constructed wetlands are being used in
Israel for decentralized treatment of domestic
wastewater. When treated with the UV
disinfection unit, the effluent of the recirculating
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vertical flow constructed wetland (RVFCW)
consistently met the stringent Israeli E, coli
standards for reclaimed water irrigation of less
than 10 cfu/IOO 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 commercially-
harvested 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. [US-
AZ-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-FL-
Orlando Wetlands] are also inviting places for popular
recreational activities, including hiking, fishing, bird-
watching, photography, and hunting. In addition to the
many ways wetlands provide recreational benefits,
they also offer numerous less-tangible benefits. These
include providing aesthetic value to residential
communities, reducing streambank erosion, and
providing educational opportunities as an ideal
"outdoor classroom," as demonstrated at the Sidwell
Friends School case study [US-DC-Sidwell Friends].
The school, in Washington, D.C., incorporated a
constructed wetland into its middle school building
renovation. This water reuse system was part of an
overall transformation of a 50-year-old facility into an
exterior and interior teaching landscape that seeks to
foster an ethic of social and environmental
responsibility in each student. With a focus on smart
water management, a central courtyard was
developed with a rain garden, pond, and constructed
wetland that uses stormwater and wastewater for both
ecological and educational purposes. More than 50
plant species, all native to the Chesapeake Bay
region, were included in the landscape.
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3.4.2 River or Stream Flow Augmentation
Among the numerous water industry challenges are
high demand and inadequate supplies. Water
conservation and reuse can reduce the demand on
aquifers, as can river or stream flow augmentation.
River and stream augmentation differs from a surface
water discharge in several ways. Augmentation seeks
to accomplish a benefit, such as aesthetic purposes or
enhancement of aquatic or riparian habitat, whereas
discharge is primarily for disposal. River or stream flow
augmentation may provide an economical method of
ensuring water quality, as well as having other
benefits. It can minimize the challenge of locating a
reservoir site, the additional water can improve the
overall water quality of the receiving water body, and it
can ameliorate the effect of low flow drought
conditions, providing high quality water at the time of
test need. River and stream augmentation may also
reduce or eliminate water quality impairment and may
be desirable to maintain stream flows and to enhance
the aquatic and wildlife habitat, as well as to maintain
the aesthetic value of the water courses. This may be
necessary in locations where a significant volume of
water is drawn for potable or other uses, largely
reducing the downstream volume of water in the river
or stream.
As with impoundments, water quality requirements for
river or stream augmentation will be based on the
designated use of the water course and the aim to
enhance an acceptable appearance. In addition, there
should be an emphasis on creating a product that can
promote native aquatic life. The quality of the
reclaimed water discharged to the receiving water
body is critical to evaluating its benefits to the stream.
Currently, there are limited data available to assess
such water augmentation schemes a priori, and
detailed, site-specific evaluations are needed (WRRF,
2011 a). 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
disrupters (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
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warranted, because aquatic organisms can be more
sensitive to certain constituents than humans (NRC,
2012).
Lake Elsinore, southern California's largest natural
lake, is fed only by rain and natural runoff, with an
annual evaporation rate of 4.5 ft. Because of these
characteristics, the lake has been plagued for decades
by low water levels and high concentrations of
nutrients. The Elsinore Valley Municipal Water District
(EVMWD) implemented a project to transfer 5 million
gallons of reclaimed water per day to the lake to help
with the low water levels [US-CA-Elsinore Valley].
3.5 Industrial Reuse
Traditionally, pulp and paper facilities, textile facilities,
and other facilities using reclaimed water for cooling
tower purposes, have been the primary industrial
users of reclaimed water. Since the publication of the
2004 Guidelines for Water Reuse, the industrial use of
reclaimed water has grown in a variety of industries
ranging from electronics to food processing, as well as
a broader adoption by the power-generation industry.
Over the past few years, these industries have
embraced the use of reclaimed water for purposes
ranging from process water, boiler feed water, and
cooling tower use to flushing toilets and site irrigation.
Additionally, industries and commercial establishments
seeking LEED certification are driven to reclaimed
water to enhance their green profile. In addition, these
facilities recognize that reclaimed water is a resource
that can replace more expensive potable water with no
degradation in performance for the intended uses.
When reclaimed water was first used for industrial
purposes (dating back to the first pulp and paper
industries), it was generally treated and reused on-site.
As water resources in the arid states have become
increasingly stressed (Arizona, California, and Texas)
and availability of groundwater sources are becoming
extremely limited (Florida), municipal facilities have
started to produce reclaimed water for irrigation,
industrial, and power company users. This section
examines water reuse in traditional industrial settings
(cooling towers and boiler water feed) and discusses
emerging industries, such as electronics and produced
waters from natural gas operations. Additional
discussion on state guidelines and regulations for
industrial reuse is provided in Section 4.5.2.8.
Case study examples of industrial water reuse to
address energy and sustainability goals include reuse
projects by companies such as Coca-Cola, Frito-Lay,
and Intel [US-AZ-Frito Lay]. Coca-Cola has installed
recycle-and-reclaim loops in 12 of its water treatment
systems in North America and Europe, with goals of
equipping up to 30 facilities with these systems by the
end of 2012. These loops allow facilities to reuse
processed water in cooling towers, boilers, or cleaning,
saving an average of 57 million gallons (220 million
liters) of water per system annually.
3.5.1 Cooling Towers
Cooling towers are recirculating evaporative cooling
systems that use the reclaimed water to absorb
process heat and then transfer the heat by
evaporation. As the cooling water is recirculated,
makeup water (reclaimed water) is required to replace
water lost though evaporation. Water must also be
periodically removed from the cooling water system to
prevent a buildup of dissolved solids in the cooling
water. There are two common types of evaporative
cooling water systems—cooling towers and spray
ponds. Spray ponds are not widely used and generally
do not utilize reclaimed water. Cooling towers have
become very efficient, with only 1.5 to 1.75 percent of
the recirculated water being evaporated for every 10°F
(6°C) drop in process water temperature, reducing the
need to supplement the system flow with makeup
water. Because water is evaporated, dissolved solids
and minerals remain in the recirculated water, and
these solids must be removed or treated to prevent
accumulation on equipment. Removal of these solids
is accomplished by discharging a portion of the cooling
water, referred to as blow-down water, which is usually
treated by a chemical process and/or a filtration/
softening/clarification process before disposal to a
local WWTP. Cooling tower designs vary widely. Large
hyperbolic concrete structures can range from 250 to
400 ft (76 to 122 m) tall and 150 to 200 ft (46 to 61 m)
in diameter and are common at utility power plants, as
shown in Figure 3-5.
These cooling towers can recirculate (cool)
approximately 200,000 to 500,000 gpm (12,600 to
31,500 L/s) and evaporate approximately 6,000 to
15,000 gpm (380 to 950 L/s) of water. Smaller cooling
towers, which may be used at a variety of industries,
can be rectangular boxes constructed of wood,
concrete, plastic, and/or fiberglass-reinforced plastic
with circular fan housings for each cell. Each cell can
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I
Figure 3-5
Large hyperbolic cooling towers (Photo Courtesy of International Cooling Towers)
recirculate (cool) approximately 3,000 to 5,000 gpm
(190 to 315 Us). 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 Us).
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.
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3.5.2 Boiler Water Makeup
The use of reclaimed water for boiler make-up water
differs little from the use of conventional potable
water—both require extensive pretreatment. Water
quality requirements for boiler make-up water depend
on the pressure at which the boiler is operated; in
general, higher pressures require higher-quality water.
The primary concern is scale buildup and corrosion of
equipment. Control or removal of hardness from either
potable water or reclaimed water is required for use as
boiler make-up; additionally, control of insoluble scales
of calcium and magnesium, and control of silica and
alumina, are also required. Alkalinity of the reclaimed
water, as determined by its bicarbonate, carbonate,
and hydroxyl content, is also of concern because
excessive alkalinity concentrations in boiler feed water
may contribute to foaming and other forms of
carryover, resulting in deposits in superheater,
reheater, and turbine units. Bicarbonate alkalinity in
feed water breaks down under the influence of boiler
heat to release carbon dioxide, a major source of
Table 3-8 Recommended boiler water limits
Drum Operating
Pressure (psig)
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
301-450 451-600 601-750 751-900
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)
Alkalinity max (ppm)
TSS Max (ppm)
Conductivity max
(umho/cm)
Silica max (ppm SiO2)
700-3500
350
15
1100-
5400
150
600-
3000
300
10
900-
4600
90
500-
2500
250
8
800-
3800
40
200-
1000
200
3
300-
1500
30
150-750
150
2
200-
1200
20
125-625
100
1
200-
1000
8
100
n/a
1
150
2
50
n/a
n/a
80
1
0.05
n/a
n/a
0.15-
0.25
0.02
Feed Water (Condensate and Makeup, After Deaerator)
Dissolved Oxygen
(ppm 02)
Total Iron
(ppm Fe)
Total Copper (ppm Cu)
Total Hardness
(ppm CaCOS)
pH@25°C
Nonvolatile TOC
(ppm C)
Oily Matter
(ppm)
0.007
0.1
0.05
0.3
8.3-10.0
1
1
0.007
0.05
0.025
0.3
8.3-10.0
1
1
0.007
0.03
0.02
0.2
8.3-10.0
0.5
0.5
0.007
0.025
0.02
0.2
8.3-10.0
0.5
0.5
0.007
0.02
0.015
0.1
8.3-10.0
0.5
0.5
0.007
0.02
0.01
0.05
8.8-9.6
0.2
0.2
0.007
0.01
0.01
ND
8.8-9.6
0.2
0.2
0.007
0.01
0.01
ND
8.8-9.6
0.2
0.2
n/a
0.01
0.002
ND
n/a
ND
ND
Source: Boiler Water Quality Requirements and Associated Steam Quality for Industrial/Commercial and Institutional Boilers
(American Boiler Manufacturers Association, 2005)
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first-pass RO treatment and disinfection) passes
through RO a second time (second pass) to remove
additional dissolved solids from the water. For water
fed to the Chevron refinery in El Segundo, Calif., about
5.8 mgd (254.1 L/s) receives single-pass RO treatment
low-pressure boiler feed, while an additional 2.4 mgd
(105 L/s) receives second-pass RO treatment for high-
pressure 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.
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.).
Other States
20%
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.
Louisiana 5%
Kansas 6%
Oklahoma 11%
20.7 billion
bbl/yr
U.S. produced
water volume
(2007)
69.8 billion bbl/yr
Worldwide produced
water volume
Texas 35%
California 12%
Wyoming 11%
Figure 3-6
Estimates of produced water by state (GWI, 2011)
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It is of interest to note that under current regulations,
produced water can only be utilized west of the 99
meridian and the practice is most contentious. Where
produced water can be used, as with reclaimed water
produced from treated municipal effluent, there are a
variety of uses depending on the produced water
quality and the level of treatment provided. Low TDS
water sources, such as those common with coalbed
methane production, may be reused with very little
treatment (NRC, 2010). Higher TDS sources usually
require a much higher level of treatment and may be
limited in their end uses. End uses of treated,
produced water include surface water flow
augmentation, aquifer recharge, storage and recovery,
crop irrigation, and livestock watering. Produced water
may also be used for a variety of industrial purposes,
especially in areas where freshwater resources are
scarce. It is important to note that produced waters
associated with hydraulic fracturing operations cannot
be used as reclaimed water for alternative uses
without extensive and expensive treatment operations,
and reuse is limited to development of additional wells,
with appropriate treatment.
Treatment of produced water is often required before
the water can be put to beneficial reuse. The degree of
treatment and the type of treatment technology used is
based on a number of factors, including the produced
water quality, volume, treated water quality objectives,
options available for disposal of residual waste (such
as concentrated brine), and cost. In oil and gas
operations, it is sometimes necessary to use modular
technologies that can be mobilized for localized
treatment in the field versus building a fixed-based
treatment facility in a central location. The overall
objective is to develop a simple, cost-effective
treatment solution capable of consistently meeting
effluent treatment objectives. Because of the wide
variation in produced water quality and treatment
objectives in oil and gas fields across the United
States, development of the best solution is challenging
and often requires a combination of treatment
technologies to meet the individual needs of each
operator. Treatment technologies commonly used for
produced water prior to reuse include oil-water
separators, dissolved gas flotation or coalescing media
separators, adsorption, and filtration targeted for
removal of specific constituents from the produced
water. As a result, the best approach must balance
produced water quality, simplicity of operations,
treatment objectives, and cost.
3.5.4 High-Technology Water Reuse
The use of reclaimed water in high-technology
manufacturing, such as the semiconductor industry, is
a relatively new practice. Within the semiconductor
industry, there are two major processes that use
water: microchip manufacturing, which has rarely
utilized reclaimed water, and the manufacture of circuit
boards. In circuit board manufacturing, water is used
primarily for rinse operations; similar to production of
boiler feed water, reclaimed water for circuit board
manufacturing requires extensive treatment. While
only circuit board manufacturing uses reclaimed water
in the actual production process, both semiconductor
and circuit board manufacturing facilities do use
reclaimed water for cooling water and site irrigation.
Examples of reuse in high-technology industries
include projects by companies such as Intel, that
improved the efficiency of the process used to create
the ultra-pure water (UPW) required to clean silicon
wafers during fabrication. Previously, almost 2 gallons
of water were needed to make 1 gallon of UPW.
Today, Intel generates 1 gallon of UPW from between
1.25 and 1.5 gallons. After using UPW to clean wafers,
the water is suitable for industrial purposes, irrigation,
and many other needs. Intel's factories are equipped
with complex rinse-water collection systems with
separate drains for collecting lightly contaminated
wastewater for reuse. This reuse strategy enables Intel
to harvest as much water from its manufacturing
processes as possible and then direct it to equipment
such as cooling towers and scrubbers. In addition,
several of Intel's locations take back graywater from
local municipal water treatment operations for
municipal use. In 2010, Intel internally recycled
approximately 2 billion gallons (7.6 MCM) of water,
equivalent to 25 percent of its total water withdrawals
for the year.
3.5.5 Prepared Food Manufacturing
The food and beverage manufacturing industry was
initially reluctant to use—and publicize the use of—
reclaimed water because of public perception
concerns. As knowledge of water reuse principles has
increased, so has the reuse of highly-treated process
waters that meet water quality criteria and address
public health concerns. In many cases, not only is
reuse of water at a manufacturing site "green," but it
also can reduce operating costs and an industry's
water footprint and, in some cases, provide better
water quality than the public water supply.
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Because of the interest in reuse for the food and
beverage industry, the International Life Sciences
Institute Research Foundation (ILSIRF) was requested
to develop guidelines for water recovery for multiple
uses in beverage production facilities. Many beverage
producers and food processors are experiencing
multiple pressures to find ways to minimize the total
volume of water they use in the production of product.
Producers need to secure adequate, predictable, and
sustainable supplies of water for all uses at reasonable
costs, and with efficient usage to maximize product
output. Reducing the "water footprint" of a facility that
is feeling these pressures allows for greater production
of product and less waste, as well as realizing possible
economic advantages, and possibly better relations
with local citizens and governments. Companies such
as Coca-Cola and PepsiCo are implementing practices
to improve their water use in their operations as further
described in case study examples of water recovery
practices at beverage processing facilities [US-GA-
Coca-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).
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Reuse and waste load reduction combined in a new
facility in Spartanburg, S.C., with expansion of New
United Resource Recovery Corporation, LLC.
(NURRC), a joint venture formed in 2007 between
Coca-Cola Company and United Resource Recovery
Corporation (URRC). NURRC recycles discarded
plastic beverage bottles and other food product
containers into NSF-certified reclaimed plastic for the
bottling and beverage industry. When proposing a ten-
fold 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 IDS less than 100 mg/L; the
reclaimed water is now used in multiple nonpotable
processes throughout the facility. On-site pre-
treatment 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
etal., 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 ",4 repeated thesis
for the last 10 to 20 years has been that advanced
wastewater treatment provides a water of such high
quality that it should not be discharged but put to
further use. This thesis when joined to increasing
problems of water shortage, provides a realistic
atmosphere for considering the reuse of wastewater.
However, at this time, there is no way to determine the
acceptability of renovated wastewater for potable
purposes." This demonstrates that more than 30 years
ago there was recognition of the importance of reuse
for potable purposes as well as acknowledgement that
what was known about the quality of the treated
wastewater was a limitation to this practice.
Since that time, a great deal has changed with respect
to our understanding of this concept. The 2012 NRC
report presents a brief summary of the nation's recent
history in water use and shows that although reuse is
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Chapter 3 Types of Reuse Applications
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 full-
scale 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-CA-
Vander Lans].
Implementation of technologies for increasingly higher
levels of treatment for many of these IPR projects has
led to questions about why reclaimed water would be
treated to produce water with higher quality than
drinking water standards, and then discharged to an
aquifer or lake. This realization has led to new interest
in DPR, utilizing the various multiple-barrier treatment
technologies. However, even with the numerous
successful IPR projects, such as cited in Table 3-9,
and technology advances, Windhoek, Namibia, was
the first city to implement long-term DPR without use
of an environmental buffer. This is an example of the
distinction between IPR and DPR: a reuse practice in
which purified municipal wastewater is introduced into
a water treatment plant intake (after treatment to at
least near drinking water quality) for the purposes of
this document, or directly into the water distribution
system after meeting drinking water standards which
has been proposed by others (Tchobanoglous et al.,
2011).
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Chapter 3 | Types of Reuse Applications
Table 3-9 Overview of selected planned indirect and direct potable reuse installations worldwide (not intended to be a
complete survey)
Country
Belgium
India
Namibia
United States
United States
United States
United
Kingdom
Singapore
South Africa
City
Wulpen
Bangalore
(planned)
Windhoek
Big Spring,
Texas
Upper
Occoquan,
Virginia
Orange County,
California
Langford
Singapore
Malahleni
Project
Capacity
(mgd)
1.9
36
5.5
3
54
40
10.5
122
4.2
Description of Advanced System for
Potable Reuse Case Study
Reclaimed water is returned to the aquifer
before being reused as a potable water source
Reclaimed water will be blended in the
reservoir, which is a major drinking water
source
Reclaimed water is blended with
conventionally-treated surface water for
potable reuse
Reclaimed water is blended with raw surface
water for potable reuse
Reclaimed water is blended in the reservoir,
which is a major drinking water source
Reclaimed water is returned to the aquifer
before being reused as a potable water source
Reclaimed water is returned upstream to a
river, which is the potable water source
Reclaimed water is blended in the reservoir,
which is a major drinking water source
Reclaimed water from a mine is supplied as
drinking water to the municipality
[Belgium-Recharge]
[India-Bangalore]
(NAS, 2012)
[US-TX-Big Spring]
[US-VA-Occoquan]
[US-CA-Orange County]
[United Kingdom-
Langford]
[Singapore-NEWater]
[South Africa-eMalahleni
Mine]
Source: Adapted from Von Sperling and Chernicharo (2002)
The rationale for DPR is based on the technical ability
to reliably produce purified water that meets all
drinking water standards and the need to secure
dependable water supplies in areas that have, or are
expected to have, limited and/or highly variable
sources. A unique DPR project has been successful
aboard the International Space Station [US-TX-NASA].
However, although reclaimed water can be treated to
meet all applicable standards, DPR still raises a
number of issues and requires a careful examination
of regulatory requirements, health concerns, project
management and operation, and public perception.
Many of these issues have been discussed in greater
detail with respect to how regulatory agencies and
utilities in California would pursue DPR as a viable
option in the future (Crook, 2010).
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
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Chapter 3 Types of Reuse Applications
Precipitation and Surface Runoff
Conventional Water Supply
Surface Water Groundwater
Blending
J
Potable
Water Treatment
Public
Water
System
r
Distribution
System
^.K »
v Non-Public Systems Only
.
1 * i ^
A public water system is a system for the provision (o the public of water
for human consumption through pipes or other constructed conveyances.
See EPA Safe Drinking Water Act definitions.
Environmental Buffer (*-°- s^pore NEWater and
Upper Occoquan Service Authority,
IPR Surface Water ^ Virginia)
IPR
IPR
Supply Reservoirs
Groundwater
Aquifer
(e.g. Orange County Water District
Groundwater Replenishment System,
^ California)
Water
Users
Wastewater Treatment
^^^^^^^^^^Bl
Conventional ^ Advanced
I Wastewater Treatment Wastewater Treatment
Figure 3-7
Planned IPR scenarios and examples
linked to benefits to the discharger or community in
increasing the yield of water supplies that they depend
on either directly or indirectly. While satisfying these
four factors may be necessary to pursue IPR, they are
not sufficient. Two specific components of these
factors typically control the viability of implementation.
First, even though existing water supplies may be of
limited availability and yield, the means via water
rights, permits, and storage contracts must exist to
reap the benefits of withdrawing the additional yield of
the augmented water supply. Second, public
acceptance of IPR is of paramount importance but
sometimes takes counterintuitive turns based on the
specifics of the project and the local community. The
following examples illustrate how these key
components can play out in project planning and
implementation.
An often-cited example of IPR is the UOSA discharge
into Occoquan Reservoir in Northern Virginia. In this
particular case, serious water quality issues were
caused by multiple small effluent discharges into the
reservoir. The Fairfax County Water Authority
withdraws water from the reservoir to meet the water
supply needs of a large portion of Northern Virginia. In
Potable
Water Treatment
Other Types of
Reuse and/or
Discharge to
Receiving
Water Bodies
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 [US-
VA-Occoquan] for further information.
Another example is the Gwinnett County, Ga., where
treated effluent is discharged to Lake Lanier. Operated
by the USAGE, 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
2012 Guidelines for Water Reuse
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Chapter 3 | Types of Reuse Applications
reclaimed water to the lake, the first key component
was satisfied by the issuance of a revised state
withdrawal permit and amended USAGE 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 I PR 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 I PR
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.
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Chapter 3 Types of Reuse Applications
Precipitation and Surface Runoff
1
Conventional Water Supply
Surface Water Groundwater
DPR^
DP
R^
k
]
r
Blending
i
Potable
Water Treatment
Public
Water
System
r
Distribution
System
£
Water
Users
' K
K le.g. Big Spring, Texas)
W
1
0
1
....1
Note:
A public water system is a system for the provision to the public of water
for human consumption through pipes or other constructed conveyances.
See EPA Safe Drinking Water Act definitions.
H k.
|J Conventional I^J Advanced ^ Potable Reuse and/or
n Wastewater Treatment PH Wastewater Treatment | Water Treatment Discharged
1^ .
\ (e.g. Cloudcroft, New Mexico)
Figure 3-8
Planned DPR and specific examples of implementation
In the first option, purified water is first placed in an
engineered storage buffer; from there, purified water is
blended with the water supply prior to water treatment.
In the second option, purified water, without the use of
an engineered storage buffer, can be blended back
into the distribution system for delivery to water users.
An in-depth discussion of implementation of these
options is provided by Tchobanoglous et al. (2011)
and Levernez et al. (2011), along with the concept and
role of the engineered storage buffer, which is a
mechanism for detention to provide response time for
any off-specification product water.
Multiple additional process configurations may be
available, such as the configuration in Big Spring,
Texas, where direct blending of highly-treated
reclaimed water with quality higher than drinking water
standards is provided in a raw, surface water
transmission main supplying six different community
surface water treatment plants. In this particular
project, the low TDS DPR water blends in the
transmission main with significantly higher TDS lake
water, improving the blended source water quality [US-
TX-Big Spring].
In many parts of the world, DPR may be the most
economical and reliable method of meeting future
water supply needs. While DPR is still an emerging
practice, it should be evaluated in water management
planning, particularly for alternative solutions to meet
urban water supply requirements that are energy
intensive and ecologically unfavorable. This is
consistent with the established engineering practice of
selecting the highest quality source water available for
drinking water production. Specific examples of
energy-intensive or ecologically-challenging projects
include interbasin water transfer systems, which can
limit availability of local water sources for food
production, and source area ecosystems, which are
often impacted by reduced stream flow and
downstream water rights holders who could exercise
legal recourse to regain lost water. In some
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Chapter 3 | Types of Reuse Applications
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 I PR 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 I PR,
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
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Chapter 3 Types of Reuse Applications
• Identify better indicators and surrogates that can
be used to monitor process performance in
reuse scenarios and develop online real-time or
near real-time monitoring techniques for their
measurement
• Analyze the need for new reuse approaches
and technology in future water management
3.8 References
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Water Quality Requirements and Associated Steam Quality
for Industrial/Commercial and Institutional Boilers. ABMA.
Vienna, VA.
American Water Works Association (AWWA). 2010. "New
Orleans Plans to Restore Wetlands Using Effluent Have
'Wow' Factors." Streamlines. 2(24).
American Society of Civil Engineers (ASCE). 2012.
Agricultural Salinity Assessment and Management, Manuals
of Practice (MOP) 71. ASCE Press. Reston, VA.
Associated Press. 2012. "Federal Court Rejects Challenge
to Arizona Snowbowl's Mountain Snow-making Plan,"
Arizona Capital Times, February 10, 2012.
Barber, L. B., A. M. Vajda, C. Douville, D. O. Morris, and J.
H. Writer. 2012. Fish Endocrine Disruption Responses to a
Major Wastewater Treatment Facility Upgrade.
Environmental Science & Technology. 46(4):2121 -2131.
Baydal, D. 2009. "Municipal Wastewater Recycling Survey."
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Bryk, J., R. Prasad, T. Lindley, S. Davis, and G. Carpenter.
2011. National Database of Water Reuse Facilities:
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California Department of Public Health. 2009. Water
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.
California State Water Resources Control Board (California
SWRCB). 2009. Recycled Water Policy. Retrieved July
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Cirelli, G. L., S. Consoli, F. Licciardello, R. Aiello, F.
Giuffrida, and C. Leonard!. 2012. Treated Municipal
Wastewater Reuse in Vegetable Production. Agricultural
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Clark, C. E., and J. A. Veil. 2009. Produced Water
Volumes and Management Practices in the United
States. Argonne, Illinois: Argonne National Laboratory.
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.
Cooper, N. B., A. G. Fishbeck, and T. Barker. 2011.
"Extreme Water Reuse - Water Recycling in a Food
Products Industry." WateReuse Association Symposium,
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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. 2070 Reuse Inventory. Florida Department of
Environmental Protection. Tallahassee, FL. Retrieved
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.
Food and Agriculture Organization of the United Nations
(FAO). 2011. Executive Summary. Thirty-seventh Session
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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."
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Global Water Intelligence (GWI). 2011. Produced Water
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North America. Media Analytics Ltd. Oxford, UK.
Global Water Intelligence (GWI). 2009. Municipal Water
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Chapter 3 | Types of Reuse Applications
Golf Course Superintendents Association of America
(GCSAA) and The Environmental Institute for Golf (GCSSA
and EIFG). 2009. Golf Course Environmental Profile,
Volume II, Water Use and Conservation Practices on U.S,
Golf Courses. GCSAA. Lawrence, KS. Retrieved on August
23, 2012 from
.
Grinnell, G. K., and R. G. Janga. 2004. Golf Course
Reclaimed Water Marketing Survey. American Water Works
Association. Denver, CO.
Hall, J. R., Ill; 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 -
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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 well-
established 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.
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-1 Key elements of a water reuse program (Adapted from WateReuse Association, 2009)
I Factor I Description
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Establish the objectives
Commit to the long run
Identify the lead agency or
agencies
Identify water reuse leader
Enact needed legislation
Adopt and implement rules
or guidelines governing
water reuse
Be proactive
Develop and cultivate
needed partnerships
Ensure the safety of water
reuse
Develop specific program
components
Focus on quality, integrity,
and service
Be consistent
Promote a water reuse
community
Maintain a reuse inventory
Address cross-connection
control issues
Objectives that encourage and promote reuse should be clear and concise.
A water reuse program should be considered a permanent, high-priority program within the state.
The lead agencies should be able to issue permits for the production, distribution, and use of the reclaimed water.
These permits are issued under state authority and are separate from the federal requirements for wastewater
discharges to surface waters under the NPDES permit program. Preference to the lead agency determination should
be given to the public health agency since the intent of the use of reclaimed water is for public contact and/or
consumption following adequate and reliable treatment.
A knowledgeable and dedicated leader of the water reuse program who develops and maintains relationships with all
water programs and other agencies should be designated.
Initial legislation generally should be limited to a clear statement of the state objectives, a clear statement of
authorization for the program, and other authorizations needed for implementation of specific program components.
States also will want to review and evaluate existing state water law to determine what constraints, if any, it will
impose on water reuse and what statutory refinements may be needed.
With stakeholder involvement, a comprehensive and detailed set of reuse regulations or guidelines that are fully
protective of environmental quality and public health should be developed and adopted in one location of the
regulations. Formal regulations are not a necessity— they may be difficult and costly to develop and change and
therefore overly rigid. Frameworks that have an ability to adapt to industry changes are most effective.
The water reuse program leader should be visible within the state and water reuse community while permitting staff of
the lead agency must have a positive attitude in reviewing and permitting quality water reuse projects.
Partnerships between the agency responsible for permitting the reclaimed water facilities (usually the lead agency)
and the agency(ies) responsible for permitting water resources as well as the agency responsible for protection of
public health are critical. Other agency partnerships, such as with potential major users of reclaimed water such as
the department of transportation, are also helpful in fostering state-wide coordination and promotion of water
reclamation.
Ensuring the protection of public health and safety can be accomplished by placing reliance on production of high-
quality reclaimed water with minimal end use controls, or allowing lower levels of treatment with additional controls on
the use of reclaimed water (setback distances, time of day restrictions, limits on types of use, etc.), or by a
combination of both types of regulations. A formal reliability assessment to assure a minimum level or redundancy
and reliability to review and detail operating standards, maintainability, critical operating conditions, spare parts
requirements and availability, and other issues that affect the ability of the plant to continuously produce reclaimed
water. A critical component to ensuring the safety of reclaimed water for public access and contact-type reuse is
defining requirements for achieving a high level of disinfection and the monitoring program necessary to ensure
compliance (this is described further in Chapter 6).
Program components are going to differ from state to state and maturity of the reuse program.
Not only should the reclaimed water utilities implement high-quality reuse systems that are operated effectively, but
the lead agency should also model this commitment to quality and prompt service to the regulated and general public
regarding reuse inquiries and permitting issues. In effect, the lead agency should focus on building same level of trust
public potable water systems develop and re-establish daily.
A comprehensive and detailed set of state regulations, as well as having a lead reuse role, help keep the permitting of
reuse systems consistent. If there are multiple branches around the state involved in permitting, training and other
measures of retaining consistency must be taken.
The lead agency should be proactive in developing and maintaining the state's water reuse community— reuse
utilities, consulting engineers, state agencies, water managers, health departments, universities, researchers, users of
reclaimed water, and others— in an effort to disseminate information and obtain feedback related to possible
impediments, issues, and future needs. Active participation in the national and local reuse organizations is valuable.
Maintenance of a periodical (e.g., annual) reuse inventory is essential in tracking success of a state's water reuse
program. Facilities in Florida that provide reclaimed water are required by their permits to submit an annual reuse
report form every year. That data not only is used in the states annual reuse inventory report and reuse statistics but
is also shared with the WateReuse Association's National Reuse Database.
Coordination and joint activity between agencies and within agencies (drinking water program, wastewater program,
water reuse program, etc.) must be taken to address cross-connection control issues (this is described further in
Chapter 2).
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Chapter 4 State Regulatory Programs for Water Reuse
Table 4-2 Fundamental components of a water reuse regulatory framework for states
^
Category Comment
Purpose and/or goal
statement
Definitions
Scope and applicability
Exclusions and
prohibitions
Variances
Permitting requirements
Define or refine control
and access to reclaimed
water
Relationship to other
rules
Relationship to
stakeholders
Relationship to
regulations or guidelines
for uses of other non-
conventional water
sources
Reclaimed water
standards
Treatment technology
requirements
Monitoring requirements
Criteria or standards for
design, siting, and
construction
• Frame the state's purpose for developing the rule or regulation (e.g., to satisfy a need or fulfill a statutory requirement), and
describe the ultimate vision for the water reuse program. The process to authorize, develop, and implement rules or
changes to rules is time consuming and costly. After adoption, rules are difficult to change, which limits the ability to
accommodate new technologies and information.
• Define type of use and other water reuse-related terms used within the body of the rule or regulation.
• Define the scope and applicability of the rules or regulations that delineates what facilities, systems, and activities are
subject to the requirements of the rules or regulations.
• Include grandfathering or transitioning provisions for existing facilities, systems, or activities not regulated prior to the
adoption of the rules or regulations.
• Describe facilities, systems and activities that are 1 ) not subject to the requirements of the rules or regulations, and 2)
specifically prohibited by the rules or regulations.
• Describe procedures for variances to design, construction, operation, and/or maintenance requirements of the regulation for
hardships that outweigh the benefit of a project, and the variance, if granted, would not adversely impact human health,
other beneficial uses, or the environment. These variance procedures give regulators flexibility to consider projects that may
deviate only minimally from the requirements with no significant adverse impact or opportunities that are not anticipated
during initial development of a regulation. Since variances need to be based on sound, justifiable reasons for change,
regulatory programs should develop guidance on how to develop adequate justification that can be relied upon as
precedence setting for future regulatory decisions and actions.
• Describe the permitting framework for water reuse. Indicate whether the water reuse rule or regulation will serve as the
permitting mechanism for water reuse projects or identify other regulations through which the water reuse rule or regulation
will be implemented and projects permitted.
• Describe if or how end users of reclaimed water will be permitted, and rights of end user to refuse reclaimed water if not
demanded.
• Describe permit application requirements and procedures. Specify all information that the applicant must provide in order to
appropriately evaluate and permit the water reuse projects.
• Determine the rights to and limits of access and control over reclaimed water for subsequent use and the relationship
between the underlying water right, wastewater collection system ownership, reclamation plant ownership, and downstream
water users who have demonstrated good-faith reliance on the return of the wastewater effluent into a receiving stream
within the limits and requirements of the state's water rights statutory and regulatory requirements.
• Describe relationship between water reuse rule or regulation and, for example, water and wastewater regulations,
environmental flow requirements, solid waste or hazardous waste rules, groundwater protection, required water
management plans, and relevant health and safety codes for housing, plumbing, and building.
• Identify regulatory or non-regulatory stakeholders from various sectors (e.g., water, wastewater, housing, planning,
irrigation, parks, ecology, public health, etc.) that have a role or duty in the statewide reuse program.
• Describe other rules or regulations that exist for graywater recycle and stormwater or rainwater harvesting and use.
• Some states may choose to develop a more comprehensive approach that encompasses rules or regulations for all non-
conventional water sources, including water reuse, within one set of rules or regulations.
• See Tables 4-6 to 4-15 for standards that are either defined by end use or by degree of human contact.
• Include a provision to evaluate and allow standards to be developed on a case-by-case basis for less common uses of
reclaimed water that are not listed.
• Require points of compliance to be established to verify compliance with standards.
• Describe response and corrective action for occurrence of substandard reclaimed water (a component of the Contingency
Plan, below).
• In addition to reclaimed water standards, some states specify treatment technologies for specific reuse applications.
• Describe methods and frequency for monitoring all standards listed in the rules or regulations.
• Describe criteria or standards of engineering design, siting, and construction for water reuse facilities and systems that
typically include, but are not limited to, facilities or systems to treat/reclaim, distribute, and store water for reuse.
• Develop requirements for dual plumbed distributions systems (separate distribution of potable and nonpotable water) that
are co-located.
• Describe requirements for the transfer of reclaimed water and its alternative disposal if unsuitable or not required by target
user (e.g., during wet seasons).
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-2 Fundamental components of a water reuse regulatory framework for states (cont.)
^
Category Comment
Construction requirements
Operations and maintenance
(O&M)
Management of pollutants from
significant industrial users as
source water protection
Access control and use area
requirements
Education and notification
Operational flow requirements
Contingency plan
Recordkeeping
Reporting
Stakeholder participation
Financial assistance
• Describe requirements for engineering reports, pilot studies, and certificates required to construct and to operate.
• Describe minimum requirements for the submission and content of O&M manual. The scope and content of an
O&M manual will be determined by the type and complexity of the system(s) described by the manual.
• Where facilities or systems with inputs from significant industrial users are proposing to generate reclaimed water
suitable for human contact or potable reuse, describe programs that must be implemented to manage pollutant of
concern from significant industrial users.
• Pretreatment programs of combined publicly owned treatment works and reclamation systems may satisfy program
requirements.
• Develop program requirements for satellite reclamation systems also affected by inputs from significant industrial
users.
• Such pretreatment programs should develop discharge limits that are intended to protect source water, rather than
wastewater treatment and sewer system integrity.
• Describe requirements to control access to sites where reclaimed water will be generated, or in some cases, stored
or utilized.
• Describe requirements for advisory sign placement, message, and size.
• Describe requirements for proper use of reclaimed water by end users to ensure protection of the environment and
human health (.e.g., setbacks, physical barriers or practices to prevent reclaimed water from leaving the site of use,
etc.).
• Include requirements for generators or providers of reclaimed water to educate end users of appropriate handling
and use of the water, and to provide notification to end users regarding the discharges of substandard water to
reuse and loss of service for planned or unplanned cause.
• Requirements for maintaining flow within design capacity of treatment system or planning for additional treatment
capacity as needed.
• Include a requirement for a contingency plan that describes how system failures, unauthorized discharges, or
upsets will be remedied or addressed.
• Describe what operating records must be maintained, the location where they are retained, and the minimum
period of retention.
• Describe what items must be reported, the frequency of reporting, and to whom they are reported.
• Requirements on public notice, involvement, and decision-making. This will apply where the water reuse rule or
regulation is used as the vehicle to permit water reuse projects.
• Describe state, local, or federal funding or financing sources.
4.3.1 Water Rights
Water reuse regulatory programs must work within the
prevailing water rights laws of the state. Each state in
the United States was granted ownership and control
over all waters within their boundaries at statehood.
"Water rights" provide the legal right for an entity to
divert, capture, and use water within the boundaries of
each individual state. In the United States, there are
two main approaches to water rights law—
appropriative doctrines (common in historically water-
scarce 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
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Chapter 4 State Regulatory Programs for Water Reuse
bodies rather than using the reclaimed water for other
beneficial uses. These scenarios include: 1) where
reduction in effluent discharge flows could be
challenged by downstream users, 2) where laws
require that place-of-use be located within the
watershed from which the water was originally drawn
(in the case that reclaimed water might be distributed
outside the watershed), 3) where "beneficial uses" of
higher priority can make a claim for the reclaimed
water (over, for example, industrial reuse), or 4) where
reductions in water withdrawals from water supply
because of reclamation might change customer rights
or allocations in future periods of shortage (where
rights or allocations are based on historic usage).
The most significant constraint affecting use of
reclaimed water is the need to assure minimum
instream flows sufficient to protect aquatic habitat. This
is especially necessary in locations where instream
flows are necessary to protect the habitat of
threatened and endangered fisheries. There are also
cases where federal water laws may affect or
supersede state regulatory programs for water reuse,
particularly where water reuse would impact
international boundaries (e.g., the Great Lakes, the
Tijuana River, the Colorado River), Native American
water rights, multiple states with a claim on limited
water supplies, water rights on federal property (or on
non-reserved lands), instream flow requirements to
support threatened and endangered fisheries under
the Endangered Species Act (ESA), and other federal
reserved water rights. Additional information is
available in the 2004 EPA Guidelines for Water Reuse
Chapter 5 and Potential for Expanding the Nation's
Water Supply Through Reuse of Municipal
WastewaterChapter 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 non-
compliance 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
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Chapter 4 | State Regulatory Programs for Water Reuse
establishing the right to control pollution from WWTPs,
as long as such regulations are at least as stringent as
federal rules. Major objectives of the CWA are to
eliminate all pollutant discharges into navigable
waters, stop discharges of toxic pollutants in toxic
amounts, develop waste treatment management plans
to control sources of pollutants, and to encourage (but
not require) water reclamation and reuse through
delegation agreements. Primary jurisdiction under the
CWA is with EPA, but in most states many provisions
of the CWA are administered and enforced by the
state water pollution control agencies.
Wastewater discharge regulations mostly address
treated effluent quality, but can indirectly restrict the
quantity of effluent discharged to a receiving body by
limiting the pollutant loads resulting from the
discharge. Treated wastewater discharge permits are
issued pursuant to the NPDES program under the
CWA. In addition to limits on the concentration of
specific contaminants, discharge permits may also
include limits on the total mass of a pollutant
discharged to the receiving stream—known as TMDL
limits—and on the quality of the water in the receiving
stream itself (e.g., minimum DO limits). For reuses that
involve a discharge to surface waters, such as IPR or
stream augmentation, states may choose to regulate
them through the NPDES permit program. In this case,
the discharge for the reuse would need to comply, at a
minimum, with state surface water quality standards
and any TMDLs that would apply to the particular
receiving water. Though not specifically addressed,
water reuse is encouraged by the CWA.
Discharged water quantity may also be regulated
locally by terms of the ESA or specific water rights law
as described in Section 4.3.1. The ESA has been
applied to require water users to maintain minimum
flows in western rivers to protect the habitat of various
species of fish whose survival is threatened by
increases in water demand. Such regulations may be
continuous or seasonal, and may or may not
correspond to periods associated with reclaimed water
demand as required by the NPDES permit. To ensure
compliance with the ESA, state regulatory programs
for water reuse should establish a process by which
projects that will divert all or a portion of a wastewater
treatment facility's effluent from a surface water
discharge to consumptive reuse will be coordinated
with appropriate federal (i.e., U.S. Fish & Wildlife
Service) and state agencies. Consumptive reuse
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.
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Chapter 4 State Regulatory Programs for Water Reuse
4.4.1 Water Reuse Categories
For the purposes of this chapter, the most common
water reuses regulated by states have been
inventoried and divided into water reuse categories as
described in Table 4-3. Minimum suggested regulatory
guidelines are presented in Table 4-4. Although reuse
categories and their descriptions included in an
individual state, territory, or tribe's rules, regulations or
guidelines may differ from the reuse categories and
descriptions presented in Table 4-3, the purpose of
the information provided therein is to facilitate the
comparison of existing rules, regulations and
guidelines adopted by states, territories, and tribes and
suggest minimum regulatory guidelines using common
categories.
4.4.2 Suggested Regulatory Guidelines
Table 4-4 presents suggested treatment processes,
reclaimed water quality, monitoring frequency, and
setback distances for water reuses in various
categories. These guidelines apply to domestic
wastewater from municipal or other wastewater
treatment facilities having a limited input of industrial
waste. The suggested regulatory guidelines are
predicated principally on water reclamation and reuse
information from the United States and are intended to
apply to reclamation and reuse facilities in the United
States. These guidelines may also be used by tribal
nations in establishing water reuse programs. Local
social, economic, regulatory, technological, and other
conditions may limit the applicability of these
guidelines in some countries (see Chapter 9).
4.4.3 Rationale for Suggested Regulatory
Guidelines
The rationale for the suggested treatment processes,
reclaimed water quality, monitoring frequency, and
setback distances in porous media is based on:
• Water reuse experience in the United States
and elsewhere
• Research and pilot plant or demonstration study
data
• Technical material from the literature
• Various states' reuse rules, regulations, policies,
or guidelines
• Attainability
• Sound engineering practice
• Use with a multiple barrier approach
These guidelines are not intended to be used as
definitive water reclamation and reuse criteria. They
are intended to provide reasonable guidance for water
reuse opportunities, particularly in states that have not
developed their own criteria or guidelines.
Adverse health consequences associated with the use
of raw or improperly treated wastewater are well
documented. As a consequence, water reuse
regulations and guidelines are principally directed at
public health protection and generally are based on
the control of pathogenic microorganisms for
nonpotable reuse applications and control of both
health-significant microorganisms and chemical
contaminants for IPR applications.
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-3 Water reuse categories and number of states with rules, regulations or guidelines addressing these reuse
categories 1
Number of States
or Territories with
Rules,
Regulations, or
Guidelines
Addressing
Reuse Category
32
Urban Reuse
Unrestricted
Restricted
The use of reclaimed water for nonpotable applications
in municipal settings where public access is not
restricted
The use of reclaimed water for nonpotable applications
in municipal settings where public access is controlled or
restricted by physical or institutional barriers, such as
fencing, advisory signage, or temporal access restriction
40
Food Crops
Agricultural
Reuse
The use of reclaimed water to irrigate food crops that are
intended for human consumption
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
27
43
Unrestricted
Impoundments
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)
Restricted
The use of reclaimed water in an impoundment where
body contact is restricted (some states include fishing
and boating in this category)
13
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
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
Individual state reuse programs often incorporate different terminology so the reader should exercise caution in comparing
the categories in these tables directly to state regulatory definitions
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-4 Suggested guidelines for water reuse
Reuse Category and
Description
Urban Reuse
Treatment
Reclaimed Water Quality
Reclaimed Water Monitoring
Setback Distances
Comments
Unrestricted
The use of reclaimed water in
nonpotable applications in municipal
settings where public access is not
restricted.
Secondary!4)
Filtration!6)
Disinfection'6'
pH = 6.0-9.0
< 10 mg/l BOD <7>
< 2 NTU PI
No detectable fecal coliform /100 ml <9"10>
1 mg/l CI2 residual (min.) <11>
pH - weekly
BOD - weekly
Turbidity - continuous
Fecal coliform - daily
CI2 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.
Restricted
The use of reclaimed water in
nonpotable applications in municipal
settings where public access is
controlled or restricted by physical or
institutional barriers, such as fencing,
advisory signage, or temporal access
restriction
Secondary <4'
Disinfection <6>
pH = 6.0-9.0
< 30 mg/l BOD <7>
< 30 mg/l TSS
< 200 fecal coliform /100ml <9-13-14>
1 mg/l CI2 residual (min.) <11)
pH - weekly
BOD - weekly
TSS - daily
Fecal coliform - daily
CI2 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
Food Crops75
The use of reclaimed water for
surface or spray irrigation of food
crops which are intended for human
consumption, consumed raw.
Secondary <4)
Filtration <6)
Disinfection <6)
pH = 6.0-9.0
< 10 mg/l BOD (7)
< 2 NTU m
No detectable fecal coliform/100 ml <9-10)
1 mg/l Cl2 residual (min.) <11)
pH - weekly
BOD-weekly
Turbidity - continuous
Fecal coliform - daily
Ch 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.
Processed Food Crops15
The use of reclaimed water for
surface irrigation of food crops which
are intended for human consumption,
commercially processed.
Non-Food Crops
The use of reclaimed water for
irrigation of crops which are not
consumed by humans, including
fodder, fiber, and seed crops, or to
irrigate pasture land, commercial
nurseries, and sod farms.
Secondary <4)
Disinfection <6)
pH = 6.0-9.0
< 30 mg/l BOD <7>
< 30 mg/l TSS
< 200 fecal coli/100 ml P-13-14)
1 mg/l CI2 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.
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Table 4-4 Suggested guidelines for water reuse
Description Treatment Reclaimed Water Quality 2 Reclaimed Water Monitoring Setback Distances 3 Comments
Impoundments
Unrestricted
The use of reclaimed water in an
impoundment in which no limitations
are imposed on body-contact.
Restricted
The use of reclaimed water in an
impoundment where body-contact is
restricted.
• Secondary <4)
• Filtration <6)
• Disinfection <6)
• Secondary <4)
• Disinfection <6)
• pH = 6.0-9.0
• <10mg/IBOD(7>
• < 2 NTU PI
• No detectable fecal coliform/100 mi (9-10)
• 1 mg/l CI2 residual (min.) <11)
• < 30 mg/l BOD <7>
• < 30 mg/l TSS
• < 200 fecal coliform/100 ml I9-13-14)
• 1 mg/l Cl2 residual (min.) <11)
• pH - weekly
• BOD -weekly
• Turbidity - continuous
• Fecal coliform - daily
• Cl2 residual - continuous
• pH - weekly
• TSS - daily
• Fecal coliform - daily
• Ch residual - continuous
• 500 ft (1 50 m) to potable water supply wells
(min.) if bottom not sealed
• 500 ft (1 50 m) to potable water supply wells
(min.) if bottom not sealed
• Dechlorination may be necessary to protect aquatic species of flora and fauna.
• Reclaimed water should be non-irritating to skin and eyes.
• Reclaimed water should be clear and odorless.
• Nutrient removal may be necessary to avoid algae growth in impoundments.
• Chemical (coagulant and/or polymer) addition prior to filtration may be necessary to meet water quality
recommendations.
• Reclaimed water should not contain measurable levels of pathogens. <12)
• Higher chlorine residual and/or a longer contact time may be necessary to assure that viruses and parasites are
inactivated or destroyed.
• Fish caught in impoundments can be consumed.
• See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.
• Nutrient removal may be necessary to avoid algae growth in impoundments.
• Dechlorination may be necessary to protect aquatic species of flora and fauna.
• See Section 3.4.3 in the 2004 guidelines for recommended treatment reliability requirements.
Environmental Reuse
Environmental Reuse
The use of reclaimed water to create
wetlands, enhance natural wetlands,
or sustain stream flows.
• Variable
• Secondary <4) and
disinfection <6> (min.)
Variable, but not to exceed:
• <30 mg/l BOD <7>
• < 30 mg/l TSS
• < 200 fecal coliform/100 ml I9-13-14'
• 1 mg/l Cl2 residual (min.) <11>
• BOD -weekly
• SS - daily
• Fecal coliform - daily
• Ch 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
Once-throudh Coolina
Recirculatina Cooling Towers
• Secondary <4'
• Secondary <4)
• Disinfection <6)
(chemical coagulation
and filtration t6' may be
needed)
• pH = 6.0-9.0
• < 30 mg/l BOD <7>
• < 30 mg/l TSS
• < 200 fecal coliform/100 ml I9-13-14'
• 1 mg/l Cl2 residual (min.) <11>
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>
• pH - weekly
• BOD -weekly
• TSS - weekly
• Fecal coliform - daily
• Cl2 residual - continuous
• 300 ft (90 m) to areas accessible to the
public
• 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.
• 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.
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Table 4-4 Suggested guidelines for water reuse
Description
Indirect Potable Reuse
Treatment
Reclaimed Water Qualitx
Reclaimed Water Monitoring
Setback Distances
Comments
Groundwater Recharge by
Spreading into Potable
Aquifers
Secondary <4)
Filtration <6)
Disinfection <6)
Soil aquifer treatment
Includes, but not limited to, the following:
• No detectable total coliform/100 ml (9-10>
• 1 mg/l Ch residual (min.) <11>
• pH = 6.5-8.5
• < 2 NTU m
• < 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
Ch residual - continuous
Drinking water standards - quarterly
Other <") - 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.t12'
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 <6>
Disinfection <6>
Advanced wastewater
treatment <16)
Includes, but not limited to, the following:
• No detectable total coliform/100 ml (9-1°)
• 1 mg/l Cl2 residual (min.) <11)
• pH = 6.5-8.5
• < 2 NTU m
• < 2 mg/l TOC of wastewater origin
• Meet drinking water standards
Augmentation of Surface Water
Supply Reservoirs
Secondary <4'
Filtration <6)
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.
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
0)
(2)
(3)
(4)
(5)
(6)
(7)
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.
Unless otherwise noted, recommended quality limits apply to the reclaimed water at the point of discharge from the treatment facility.
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.
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.
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.
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.
As determined from the 5-day BOD test.
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.
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.
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.
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.
It is advisable to fully characterize the microbiological quality of the reclaimed water prior to implementation of a reuse program.
The number of fecal coliform organisms should not exceed 800/100 ml in any sample.
Some stabilization pond systems may be able to meet this coliform limit without disinfection.
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.
Advanced wastewater treatment processes include chemical clarification, carbon adsorption, reverse osmosis and other membrane processes, advanced oxidation, air stripping, ultrafiltration, and ion exchange.
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.
See Section 4.4.3.7 for additional precautions that can betaken when a setback distance of 100ft (30 m) to potable water supply wells in porous media is not feasible.
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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 by-
products. 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
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Chapter 4 State Regulatory Programs for Water Reuse
human contact. Reclaimed water used for applications
where no direct public or worker contact with the water
is expected should be disinfected to achieve an
average fecal coliform concentration not exceeding
200/100 ml_ because, at this indicator bacteria
concentration:
• Most pathogens will be reduced to low levels
• Disinfection of secondary effluent to this
coliform level is readily achievable at minimal
cost
• Disinfection to lower levels may not further
decrease human health risk, because there is
no direct contact with the reclaimed water
For uses where direct or indirect contact with
reclaimed water is likely or expected, and for dual
water systems where there is a potential for cross-
connections 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.
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Chapter 4 | State Regulatory Programs for Water Reuse
• The laboratory culturing procedures to
determine the presence or absence of
pathogenic viruses in a water sample takes
about 14 days, and an additional 14 days are
required to indentify the viruses. In addition,
some enteric viruses do not have permissive
cell cultures and therefore cannot be monitored
using cell culture techniques.
• Molecular and genomic technology is providing
new tools to rapidly detect and quantify viruses
in water (e.g., nucleic acid probes and
polymerase chain reaction technology),
including viruses that are non-culturable.
However, molecular and genomic methods
currently in use are not able to differentiate
between infective and non-infective virus
particles. Therefore, these methods are useful
in examining physical removal (by filtration,
including membranes) but currently cannot fully
determine degree of inactivation through
disinfection steps. Methods that combine cell
culture with molecular and genomic techniques
may be able to improve quantification, while
also giving an indication of infectivity.
• The value of bacteriophages as indicators for
pathogenic viruses is currently an area of
debate and ongoing research.
• There have been no documented cases based
on limited epidemiological studies of viral
disease resulting from water reuse operations in
the United States.
4.4.3.4 Water Quality Requirements for
Suspended and Particulate Matter
The removal of suspended matter is related to virus
removal. Many pathogens are paniculate-associated,
and that paniculate 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
paniculate 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 paniculate 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 highly-
variable porosity or transmissivity (e.g., sensitive
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Chapter 4 State Regulatory Programs for Water Reuse
hydrogeological areas such as karst or fractured
bedrock), the ground water residence time is often too
uncertain to be useful; or protective. Overall a larger
setback distance should be considered in porous soils
compared to lower permeability soils. This is because
most soils are not well-classified or mapped. In the
absence of such information (usually gleaned from
geotechnical evaluations), a more conservative
setback distance is recommended. These setback
distances are often applied also to physical separation
between the well and any other nonpotable source in
another buried conveyance, such as sewer pipes. In
addition, most states also have parallel drinking water
regulations for well-head protection that identify
separation distances from various operations that may
introduce water into or onto sensitive areas. Where
these separation distances are not achievable,
designers/regulators should consider additional
precautions (e.g., use area controls or design
components) to maintain an adequate margin of public
health protection through the potable water system.
The recommended setback distances outlined in Table
4-4 are greater for the Restricted Urban category than
the Unrestricted Urban category and greater for the
Agricultural Reuse for Processed Food Crops and
Non-Food Crops category than for the Agricultural
Reuse for Food Crop category. These increased
recommended setback distances are to maintain
protection of public health, given that the suggested
level of treatment and resulting water quality are less
stringent than for Unrestricted Urban reuse or
Agricultural Reuse for Food Crops.
4.4.3.7 Specific Considerations for IPR
Only a limited number of states have IPR reuse
regulations, some of which are implemented through
groundwater recharge rules. In states where IPR
regulations or guidelines exist, these include
requirements for treatment processes and reclaimed
water quality and monitoring. States may specify the
requirement of a pretreatment program, pilot plant
studies, and public hearings. Water quality
requirements for IPR typically include limits for TSS,
nitrogen, TOC, turbidity, and total coliform. California
draft IPR regulations also require limits for specific
organics and design requirements for pathogen
removal. Most states also specify a minimum time the
reclaimed water must be retained in an environmental
buffer (e.g., bioretention cells, properly-designed rain
gardens, etc.) prior to being withdrawn as a source of
drinking water, or the separation distance between a
point of recharge and a point of withdrawal. As noted
in Table 4-4, it is appropriate to consider increasing
the separation distance when the project is located in
porous soils. In this context, the definition of porous
media includes soils that are sandy (sand, sandy loam,
sandy clay loam, loam), gravels, or interbedding
thereof; soil formations wherein clay lenses are not
predominant. Other sources of high-transmissivity may
be found in rural or urban areas, and call for special
consideration of well fields that border construction
landfills (where buried construction debris can exhibit
high transmissivity), and vacant lots. In addition to IPR
regulations, drinking water standards also apply to
public water supplies, since the reclaimed water will be
processed through a drinking water treatment plant
prior to potable reuse.
As needs for alternative water supplies grow,
reclaimed water is anticipated to be intentionally used
more in potable supply applications, and while no
illnesses have been directly connected to the use of
properly treated and managed reclaimed water, it is
well recognized that the understanding of the risks
from constituents of emerging concern is a rapidly
evolving field, and that regulatory requirements need
to be based on best available science. By example, in
California, the SWRCB included a provision in their
Recycled Water Policy to establish a Science Advisory
Panel to provide guidance for developing monitoring
programs that assess potential threats from chemicals
of emerging concern (CECs) and pathogens in
landscape irrigation and IPR applications.
The Science Advisory Panel's study made the
following conclusion about pathogen monitoring in
irrigation and IPR:
"Given the multiple barrier concept and water
treatment process redundancy requirements in
place, the Panel believes that the potential
public health risk associated with exposure to
pathogens in recycled water used for landscape
irrigation or groundwater recharge is very small.
However, the Panel acknowledges that some
uncertainties exist regarding the occurrence of
emerging waterborne microbial pathogens and
encourages additional research into their fate in
water reuse systems," (Anderson et al,, 2010)
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Chapter 4 | State Regulatory Programs for Water Reuse
Regarding CECs, the panel provided a conceptual
framework for determining which CECs should be
monitored out of thousands of potential targets and
applied the framework to identify a list of chemicals
that should be monitored presently, as described in
Chapter 6 (Anderson et al., 2010). The Panel also
urged California to reapply this prioritization process
on at least a triennial basis and establish a state
independent review panel that can provide a periodic
review to the CEC monitoring efforts. The most recent
draft regulations for Groundwater Replenishment
Reuse in California would require annual monitoring of
an indicator compound with the ability to characterize
the presence of Pharmaceuticals, endocrine disrupting
chemicals, personal care products, and other
indicators of the presence of municipal wastewater
(CDPH, 2011). In general, as states adopt or update
guidelines and regulations for water reuse, an
adaptive, risk-based approach to addressing reclaimed
water quality monitoring is appropriate (NRC, 2012).
When considering projects that may impact potable
aquifers, use of multiple barriers is prudent and
designers and regulators may consider the
incorporation of additional precautions for public health
protection, including:
• Multiple, independent barriers for removing and
or transforming microbiological and chemical
contaminants. Some emphasis should be
placed on gaining a better understanding of
soils via focused geotechnical site investigation
or review of geotechnical reports for the area of
interest.
• Advanced technologies that address a broader
variety of contaminants with greater reliability;
• An operational plan with documented retention
time and its effectiveness in attenuation of
contaminants for a given barrier measure; and a
monitoring program tailored to specific barriers
and local conditions with appropriate systems to
respond to potential system malfunctions.
4.4.4 Additional Requirements
In addition to reclaimed water quality and treatment
requirements, states also adopt requirements
governing monitoring, reliability, storage, and irrigation
application rates. Appendix A of the 2004 guidelines
illustrates the difference in state requirements for
many of these requirements (EPA, 2004). However, as
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
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Chapter 4 State Regulatory Programs for Water Reuse
specifications for engineered redundancy,
capacity, and backup systems (EPA, 2004).
system
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
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Chapter 4 | State Regulatory Programs 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
D 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.
Alabama
Alaska
.
Arizona
Arkansas
California
Colorado
Commonwealth
of the Northern
Mariana Islands
(CNMI)
Connecticut
Delaware
District of
Columbia
Florida
Georgia
Guam
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
D
D
•
D
•
•
•
D
•
D
•
•
D
-
-
--
--
New (2)
update
(3)
Update
Update
(4)
Update
Update
•
•
•
•
•
•
D
D
D
•
D
•
•
•
•
•
D
•
D
D
•
•
•
D
D
D
D
D
•
•
•
•
•
D
•
D
•
•
•
•
•
•
•
D
•
•
•
•
•
4-18
2012 Guidelines for Water Reuse
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Chapter 4 State Regulatory Programs 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
D 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.
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
D
D
•
D
•
•
•
•
•
•
•
•
•
•
•
•
•
•
D
--
--
--
Update
(5)
Update
Update
New (7)
Update (8)
(9)
Update
Update
Update
Update (10)
New (11)
Update
•
•
D
•
•
•
•
•
•
•
•
•
•
•
•
•
D
•
D
•
•
•
•
•
•
•
•
•
•
•
D
D
•
D
•
•
•
•
•
D
•
D
•
D
•
D
•
•
•
•
•
•
•
•
•
•
•
D
D
•
•
•
•
D
•
•
•
•
•
•
D
•
•
•
•
•
D
•
•
D
D
D
•
•
•
•
•
•
•
•
•
•
•
•
•
D
•
2012 Guidelines for Water Reuse
4-19
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Chapter 4 | State Regulatory Programs 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
D 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.
Tennessee
1 exas
Utah
Vermont
... . .
Virginia
Washington
West Virginia
Wisconsin
Wyoming
•
•
D
D
•
D
Update (12)
, , , .
IMGW ( \ 6)
(15)
Update
Update
D
•
D
•
•
•
•
D
D
•
D
•
D
D
D
•
D
D
•
D
•
D
•
D
•
D
•
(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.
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Chapter 4 State Regulatory Programs for Water Reuse
Four case studies specifically focus on policy and
regulatory processes in states around the U.S.
Arizona [US-AZ-Blue Ribbon Panel]
This case study describes the special Blue Ribbon
Panel on Water Sustainability (BRP) formed by the
Governor of Arizona in 2009. The BRP's charge
was to focus on water conservation and recycling
as strategies to improve water sustainability in
Arizona. The BRP was jointly chaired by officials
from the ADEQ, Arizona Department of Water
Resources (ADWR) and Arizona Corporation
Commission (ACC), Arizona's constitutionally
established regulatory body for privately owned
utilities. The case study describes the participatory
process the BRP went through and some of the key
recommendations.
California [US-CA-Regulations]
This case study chronicles the evolution of water
reuse laws in California, from the first water quality
guidance for the use of raw or settled sewage for
agricultural irrigation as far back as 1906 through
the 2011 draft regulations for IPR.
Virginia [US-VA-Regulations]
Virginia recently completed the process of creating
a water reuse regulation and adopted the Virginia
Water Reclamation and Reuse Regulation in 2008.
This case study describes the multiple state
agencies that play a role in regulating water reuse
in Virginia and the unique aspects of water reuse in
the state.
Washington [US-WA-Regulations]
Washington State has a reclaimed water program
governed by comprehensive guidelines that define
water quality standards and a variety of allowed
beneficial uses. This case study describes how the
State Departments of Ecology and Health jointly
administer the reclaimed water program and the
process since 2006 to develop regulations.
4.5.1.2 Reuse or Treatment and Disposal
Perspective
The underlying objectives of regulations and
guidelines vary considerably from state to state. States
such as Arizona, California, Colorado, Florida,
Georgia, Hawaii, Massachusetts, Nevada, New
Jersey, New Mexico, North Carolina, Ohio, Oregon,
Pennsylvania, Rhode Island, Texas, Utah, Virginia,
Washington, and Wyoming have developed
regulations or guidelines and standards that strongly
encourage water reuse as a water resources
conservation strategy. These states have developed
comprehensive regulations or guidelines specifying
water quality requirements, treatment processes, or
both, for the full spectrum of reuse applications. The
objective in these states is to derive the maximum
resource benefits of the reclaimed water while
protecting the environment and public health.
Other states have regulations or guidelines that focus
on land treatment of wastewater-derived effluent,
emphasizing additional treatment or effluent disposal
rather than reuse, even though the effluent may be
used for irrigation of agricultural sites, golf courses, or
public access lands. When regulations specify
application or hydraulic loading rates, the regulations
generally pertain to land application systems that are
used primarily for additional wastewater treatment for
disposal rather than reuse. When systems are
developed chiefly for the purpose of land treatment or
disposal, the objective is often to dispose of as much
effluent on as little land as possible; thus, application
rates are often far greater than irrigation demands and
limits are set for the maximum hydraulic loading. On
the other hand, when the reclaimed water is managed
as a valuable resource, the objective is to apply the
water according to irrigation needs rather than
maximum hydraulic loading, and application limits are
rarely specified. Optimal irrigation application rates are
based on site conditions (FAO, 1985).
There are many differences in the definition and
approach to water reuse between states. Due to these
differences, the same practice that may be considered
reuse in one state may be considered primarily a
means of disposal or additional "land treatment" in
another. The primary reuse of reclaimed wastewater in
South Dakota is by land application to non-food crops.
Although South Dakota has some guidelines on land
application to food crops, no one is currently doing
this. South Dakota also has a few facilities that are
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Chapter 4 | State Regulatory Programs for Water Reuse
using infiltration or evaporation/ percolation basins as
a component of their wastewater treatment facility,
rather than a disposal activity. Nevada reports similar
use of percolation basins as a disposal activity.
Florida, however, would consider this activity reuse by
surficial groundwater recharge if the percolation basins
were allowed to be loaded and rested alternately.
In most states, the release of reclaimed water to a
stream or other water body is still considered and
permitted as a point source discharge despite the fact
that it may create, enhance or sustain the water bodies
receiving that water. In Texas, reuse for stream
environmental enhancement or recreational reuse
requires a discharge permit if the supplemental
discharge point for these reuses will be at a location
different from that of the primary discharge location of
the treatment facility. For example, SAWS has a
discharge permit for the Dos Rios Water Reclamation
Facility (into the confluence of the San Antonio and
Medina Rivers), one permitted discharge upstream in
Salado Creek to maintain creek water quality, and
three permitted discharge points into the San Antonio
River to maintain flow and water quality in the San
Antonio River through the River Walk entertainment
area.
4.5.2 Summary of Ten States' Reclaimed
Water Quality and Treatment
Requirements
Reclaimed water quality and treatment requirements
are a significant part of each state's regulations and
guidelines for water reuse and may vary among the
different reuse categories listed in Table 4-5 above.
Generally, where water reuse involves unrestricted
public exposure, reclaimed water must be more highly
treated for the protection of public health. Where public
exposure is not likely, however, a lower level of
treatment is usually acceptable.
Many states include design requirements based on a
certain removal of bacterial, viral, or protozoa
pathogens for public health protection. Total and fecal
coliform counts are generally used as indicator
organisms for many bacterial pathogens and provide a
measure of disinfection process efficacy. Monitoring of
viral indicators is generally not required, though virus
removal rates are often prescribed by treatment
requirements for system design. A limit on turbidity is
usually specified as a real-time monitoring tool to verify
the performance of filtration in advanced treatment
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.
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2012 Guidelines for Water Reuse
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Chapter 4 State Regulatory Programs for Water Reuse
Table 4-6 Abbreviations of terms for state reuse rules
descriptions
Abbreviation
Annual
Average
Corrective action threshold
Day
Geometric mean
Hour
Maximum
Median
Minimum
Month
UV dose requirements including:
• 1 00 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
Product of the total residual chlorine and
contact time
Total residual chlorine
Week
Year
ann
avg
CAT
d
geom
hr
max
med
min
mon
NWRI UV
Guidelines*
CrT"
TRC
wk
yr
* Most states reference either the 2000, 2003, or 2012 NWRI
Ultraviolet Disinfection Guidelines for Drinking Water and Water
Reuse (NWRI, 2000; NWRI, 2003; NWRI, 2012). A description of
the updates to the 2012 NWRI guidelines is provided in Section
6.4.3.2.
** Also abbreviated as CT.
In addition, where TRC is listed in the tables, it is
measured after the indicated contact time.
4.5.2.1 Urban Reuse - Unrestricted
Unrestricted urban reuse involves the use of reclaimed
water where public exposure is likely in the reuse
application, thereby requiring a high degree of
treatment. In general, all states that specify a
treatment process require a minimum of secondary
treatment and disinfection prior to unrestricted urban
reuse. However, the majority of states require
additional levels of treatment that may include
oxidation, coagulation, and filtration. Texas does not
specify the type of treatment processes required but
sets limits on the reclaimed water quality. At this time,
no states have set limits on specific pathogenic
organisms for unrestricted urban reuse. However,
Florida does require monitoring of Giardia and
Cryptosporidium with sampling frequency based on
treatment plant capacity. Table 4-7 shows the
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
2012 Guidelines for Water Reuse
4-23
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Chapter 4 | State Regulatory Programs for Water Reuse
peeled, skinned, or thermally processed. Florida
requires monitoring of Giardia and Cryptosporidium
with sampling frequency, reclaimed water quality and
treatment requirements as shown in Table 4-9 for
irrigation of food crops.
4.5.2.4 Agricultural Reuse - Processed Food
Crops and Non-food Crops
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 full-
body 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-by-
case basis if no risk to public health is demonstrated.
Table 4-14 shows the reclaimed water quality and
treatment requirements for industrial reuse.
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2012 Guidelines for Water Reuse
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Chapter 4 State Regulatory Programs for Water Reuse
4.5.2.9 Groundwater Recharge - Nonpotable
Reuse
Spreading basins, percolation ponds, and infiltration
basins have a long history of providing both effluent
disposal and groundwater recharge. Most state
regulations allow for the use of relatively low quality
water (i.e., secondary treatment with basic
disinfection) based on the fact that these systems
have a proven ability to provide additional treatment.
Traditionally, potable water supplies have been
protected by requiring a minimum separation between
the point of application and any potable supply wells.
These groundwater systems are also typically located
so that their impacts to potable water withdrawal points
are minimized. While such groundwater recharge
systems may ultimately augment potable aquifers, that
is not their primary intent and experience suggests
current practices are protective of raw water supplies.
California, Florida, Hawaii, and Washington have
regulations or guidelines for reuse with the specific
intent of groundwater recharge of nonpotable aquifers.
Hawaii does not specify required treatment processes,
determining requirements on a case-by-case basis.
The Hawaii Department of Health Services bases the
evaluation on all relevant aspects of each project,
including treatment provided, effluent quality and
quantity, effluent or application spreading area
operation, soil characteristics, hydrogeology,
residence time, and distance to withdrawal. Hawaii
requires a groundwater monitoring program. Arizona
regulates groundwater recharge through their Aquifer
Protection Permit process. Washington has extensive
guidelines for the use of reclaimed water for direct
groundwater recharge of nonpotable aquifers although
all aquifers in the state are considered to be potable.
Recharge of nonpotable aquifers in Washington first
requires the redesignation of the aquifer to nonpotable.
Table 4-15 shows reclaimed water quality and
treatment requirements for groundwater recharge via
rapid-rate (surface spreading) application systems.
4.5.2.10 Indirect Potable Reuse (IPR)
IPR involves use of reclaimed water to augment
surface or groundwater sources that are used or will
be used for public water supplies or to recharge
groundwater used as a source of public water supply.
Unplanned (de facto) IPR is occurring in many river
systems today. Additionally, many types of reuse
projects inadvertently contribute to groundwater as an
unintended result of the primary activity. For example,
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.
2012 Guidelines for Water Reuse
4-25
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-7 Urban reuse - unrestricted
1
1 Unit processes
1 UVdose,
1 if UV disinfection used
1 Chlorine disinfection
1 requirements, if used
BODs
(or CBODs)
TSS
1 Turbidity
1 Bacterial indicators
Pathogens
Other
Arizona
Class A
Secondary treatment,
filtration, disinfection
A/S
A/S
A/S
A/S
-2NTU(24-hravg)
-5 NTU (max)
Fecal coliform:
-none detectable in
last 4 of 7 samples
-23/1 00m L (max)
A/S
If nitrogen > 10 mg/L,
special requirements
may be mandated to
protect groundwater
California
Disinfected Tertiary
Oxidized, coagulated,
filtered, disinfected
NWRI UV Guidelines
CrT > 450 mg-min/L;
90 minutes modal contact
time at peak dry weather
flow
A/S
A/S
-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
Total coliform:
-2.2/100ml_(7-daymed)
-23/1 00m L (not more than
one sample exceeds this
value in 30 d)
-240/1 00m L (max)
A/S
-
Florida
Secondary treatment,
filtration, high-level
disinfection
NWRI UV Guidelines
enforced, variance allowed
TRC > 1 mg/L;
15 minutes contact time
at peak hr flow1
CBODs:
-20 mg/L (ann avg)
-30 mg/L (mon avg)
-45 mg/L (wk avg)
-60 mq/L (max)
5 mg/l (max)
Case-by-case
(generally 2 to 2.5 NTU)
Florida requires continuous
on-line monitoring of turbidity
as indicator for TSS
Fecal coliform:
-75% of samples below
detection
-25/1 00m L (max)
Giardia and Cryptosporidium
sampling once each 2-yr
period for plants >1 mgd;
once each 5-yr period for
plants < 1 mgd
-
Hawaii
R1 Water
Oxidized, filtered,
disinfected
NWRI UV Guidelines
Min residual > 5 mg/L; 90
minutes modal contact time
30 mg/L or 60 mg/L
depending on design flow
30 mg/L or 60 mg/L
depending on design flow
-2 NTU (95-percentile)
-0.5 NTU (max)
Fecal coliform:
-2.2/100mL(7-daymed)
-23/1 00m L (not more than
one sample exceeds this
value in 30 d)
-200/1 00m L( max)
TR
-
Nevada
Category A
Secondary treatment,
disinfection
A/S
A/S
30 mg/L (30-d avg)
30 mg/L (30-d avg)
A/S
Total coliform:
-2.2/1 OOmL (30-d geom)
-23/1 OOmL (max)
TR
-
New Jersey
Type I RWBR
Filtration, high-level
disinfection
100mJ/cm2
at max day flow
Min residual > 1 mg/L;
1 5 minutes contact time
at peak hr flow
NS
5 mg/l
2 NTU (max) for UV
Fecal coliform:
-2.2/1 OOmL (wkmed)
-14/1 OOmL (max)
A/S
(NH3-N + N03-N)
< 10 mg/L (max)
North Carolina
Typel
Filtration
(or equivalent)
A/S
A/S
-10 mg/L (mon avg)
-15 mg/L (daily max)
-5 mg/l (mon avg)
-10 mg/l (daily max)
10 NTU (max)
Fecal coliform or £ coli:
-14/1 OOmL (mon mean)
-25/1 OOmL (max)
A/S
Ammonia as NHs-N:
-4 mg/L (mon avg)
-6 mg/L (daily max)
Texas Virginia Washington
Type I Level 1 Class A
A/S
A/S
A/S
5 mg/L
A/S
3 NTU
Fecal coliform or £ coli:
-20/1 OOmL (30-d geom)
-75/1 OOmL (max)
Enterococci:
-4/1 OOmL (30-d geom)
-9/1 OOmL (max)
A/S
-
Secondary treatment,
filtration, high-level
disinfection
A/S
TRC CAT < 1 mg/L; 30
minutes contact time
at avg flow or 20 minutes
at peak flow
10 mg/L (mon avg)
or CBODs:
8 mg/L (mon avg)
A/S
-2 NTU (daily avg),
CAT > 5 NTU
Fecal coliform:
-14/1 OOmL (mon geom),
CAT > 49/1 OOmL
£ coli:
-11/1 OOmL (mon geom),
CAT > 35/1 OOmL
Enterococci:
-11/1 OOmL (mon geom),
CAT > 24/1 OOmL
A/S
-
Oxidized, coagulated,
filtered, disinfected
NWRI UV Guidelines
Chlorine residual > 1
mg/L; 30 minutes contact
time (CrT > 30 may be
required
30 mg/L
30 mg/L; this limit is
superseded by turbidity
-2 NTU (avg)
-5 NTU (max)
Total coliform
-2.2/1 OOmL (7-dmed)
-23/1 OOmL (max)
A/S
Specific reliability or
redundancy requirements
based on formal reliability
assessment
A/S = not specified by the state's reuse regulation; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements
1 In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the
concentration of fecal coliform prior to disinfection: is < 1,000 cfu per 100 mL, the CrT shall be 25 mg-min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg-min/L; and is > 10,000 cfu per 100 mL the CrT shall be 120 mg-min/L.
2012 Guidelines for Water Reuse
4-26
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-8 Urban reuse - restricted
• ~
••?• if UV disinfection used
yjfj Chlorine disinfection
•<« requirements, if used
Is™
•"*
I-
KJH Bacterial indicators
| 0,,
Arizona
Class B
Secondary treatment,
disinfection
A/S
A/S
A/S
A/S
A/S
Fecal coliform:
-less than 200/1 00m L
in last 4 of 7 samples
-800/1 00m L (max)
If nitrogen > 10 mg/L,
special requirements
may be mandated to
protect groundwater
California
Disinfected
Secondary-23
Oxidized, disinfected
A/S
A/S
A/S
A/S
A/S
Total coliform:
-23/100mL(7-dmed)
-240/1 00 (not more than
one sample exceeds
this value in 30 d)
Florida1 R2 Water
A/S
A/S
A/S
A/S
A/S
A/S
A/S
Oxidized, disinfected
A/S
Chlorine residual > 5
mg/L, actual modal
contact time of 10 minutes
30 mg/L or 60 mg/L
depending on design flow
30 mg/L or 60 mg/L
depending on design flow
A/S
Fecal coliform:
-23/1 OOmL (7-day med)
-200/1 00m L (not more
than one sample exceeds
this value in 30 d)
Nevada
Category B
Secondary treatment,
disinfection
A/S
A/S
30 mg/L (30-d avg)
30 mg/L (30-d avg)
NS
Fecal coliform:
-2.2/1 OOmL (30-d geom)
-23/1 OOmL (max)
New Jersey
Type II RWBR
^^|
75 mJ/cm2
at max day flow
Chlorine residual > 1
mg/L; 15 minute contact
time at peak hr flow
A/S
30 mg/L
A/S
Fecal coliform:
-200/1 OOmL (mon geom)
-400/1 00m L(wk geom)
(NH3-N + N03-N):
< 10 mg/L (max)
North Carolina2
Typel
Filtration
(or equivalent)
A/S
A/S
-10mg/L(monavg)
-1 5 mg/L (daily max)
-5 mg/L (mon avg)
-10 mg/L (daily max)
10NTU(max)
Fecal coliform or E. coli:
-14/1 OOmL (mon mean)
-25/1 OOmL (daily max)
Ammonia as NHs-N:
-4 mg/L (mon avg)
-6 mg/L (daily max)
• Texas Virginia Washington
Type II | Level 2 Class C
^^^
A/S
A/S
Without pond system:
20 mg/L
(orCBOD15mg/L)
With pond: 30 mg/L
A/S
A/S
Fecal coliform or £. coli:
-200/1 OOmL (30-d geom)
-800/1 OOmL (max)
Enterococci:
-35/1 OOmL (30-day geom)
-89/1 OOmL (max)
Secondary treatment,
disinfection
NS
TRC CAT < 1 mg/L 30
minutes contact time at avg
flow or 20 minutes at peak
flow
-30 mg/L (mon avg)
-45 mg/L (max wk)
or CBODs
-25 mg/L (mon avg)
-40 mg/L (max wk)
-30 mg/L (mon avg)
-45 mg/L (max wk)
A/S
Fecal coliform:
-200/1 OOmL (mon geom),
CAT > 800/1 OOmL
E. coli:
-126/1 OOmL (mon geom),
CAT > 235/1 OOmL
Enterococci:
-35/1 OOmL (mon geom),
CAT > 104/1 OOmL
Oxidized, disinfected
NWRI UV Guidelines
Chlorine residual > 1 mg/L;
30 minutes contact time
30 mg/L
30 mg/L
A/S
Total coliform:
-23/1 OOmL (7 -d med)
-240/1 OOmL (max)
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.
2012 Guidelines for Water Reuse
4-27
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Chapter 4 State Regulatory Programs for Water Reuse
Table 4-9 Agricultural reuse - food crops
££; DismSStrtiar
m
•:•=• Unit processes
Efipl UVdose,
•JIM if UV disinfection used
iM
B'JfjJ Chlorine disinfection
fM requirements, if used
I BODs
m^l (orCBODs)
H TSS
KMl Turbidity
K9
1
Kjfl Bacterial indicators
mm
•H^l Viral indicators
mm
1 Pathogens
1 Other
Secondary
treatment, filtration,
disinfection
NS
NS
NS
NS
-2 NTU (24-hr avg)
-5 NTU (max)
Fecal coliform:
-none detectable in
last 4 of 7 samples
-23/1 OOmL (max)
NS
NS
If nitrogen > 10 mg/L,
special requirements
may be mandated to
protect groundwater
Oxidized, coagulated,
filtered, disinfected
NWRI UV Guidelines
CrT > 450 mg-min/L;
90 minutes modal
contact time at peak dry
weather flow
NS
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
Total coliform:
-2.2/1 OOmL (7-day med)
-23/1 OOmL (not more than
one sample exceeds this
value in 30 d)
-240/1 OOmL (max)
NS
NS
-
Hawaii
Florida1 I R1 Water
Secondary treatment,
filtration, high-level
disinfection
NWRI UV Guidelines
enforced, variance
allowed
TRC > 1 mg/L;
15 minutes contact time
at peak hr flow2
CBODs:
-20 mg/L (ann avg)
-30 mg/L (mon avg)
-45 mg/L (wk avg)
-60 mg/L (max)
5 mg/L (max)
Case-by-case
(generally 2 to 2.5 NTU)
Florida requires
continuous on-line
monitoring of turbidity as
indicator for TSS
Fecal coliform:
-75% of samples
below detection
-25/1 OOmL (max)
NS
Giardia, Ctyptosporidium
sampling once per 2-yr
period for plants > 1
mgd; once per 5-yr
period for plants < 1 mgd
-
Oxidized, filtered,
disinfected
NWRI UV Guidelines
Min residual > 5 mg/L,
actual modal contact time
of 90 minutes
30 mg/L or 60 mg/L
depending on design flow
30 mg/L or 60 mg/L
depending on design flow
-2 NTU (95-percentile)
-0.5 NTU (max)
Fecal coliform:
-2.2/1 OOmL (7-day med)
-23/1 OOmL (not more than
one sample exceeds this
value in 30 d)
-200/1 OOmL (max)
TR
-
Oxidized, filtered,
disinfected
New Jersey Processed NOT processed Type I Reclaimed
Nevada Type III RWBR Type 1 Type 2 Water
NP
NP
NP
NP
NP
NP
NP
NP
NP
-
Filtration, high-level
disinfection
100mJ/cm2
at max day flow
Min residual > 1 mg/L;
15 minutes contact at
peak hr flow
NS
5 mg/L
2 NTU (max) for UV
Fecal coliform:
-2.2/1 OOmL (wk med)
-14/1 OOmL (max)
NS
NS
(NH3-N + N03-N):
< 10mg/L(max)
Special information, crop
tests may be required
Filtration
(or equivalent)
NS
NS
-10 mg/L (mon avg)
-15 mg/L (daily max)
-5 mg/L (mon avg)
-10 mg/L (daily max)
10 NTU (max)
Fecal coliform or E. coli:
-14/1 OOmL (mon mean)
-25/1 OOmL (daily max)
NS
NS
Ammonia as NHs-N:
-4 mg/L (mon avg)
-6 mg/L (daily max)
Filtration, dual
UV/chlorination
(or equivalent)
dual UV/chlorination
(or equivalent)
dual UV/chlorination
(or equivalent)
-5 mg/L (mon avg)
-10 mg/L (daily max)
-5 mg/L (mon avg)
-10 mg/L (daily max)
5 NTU (max)
Fecal coliform or E. coli:
-3/1 OOmL (mon mean)
-25/1 OOmL (mon mean)
Coliphage:
-5/1 OOmL (mon mean)
-25/1 OOmL (daily max)
Clostridium:
-5/1 OOmL (mon mean)
-25/1 OOmL (daily max)
Ammonia as NHs-N:
-1 mg/L (mon avg)
-2 mg/L (daily max)
NS
NS
NS
5 mg/L
NS
3 NTU
Fecal coliform or E. coli:
-20/1 OOmL (30-dgeom)
-75/1 OOmL (max)
Enterococci:
-4/1 OOmL (30-dgeom)
-9/1 OOmL (max)
NS
NS
-
Virginia3 Washington
Level 1 Class A
Secondary treatment,
filtration, high-level
disinfection
NS
TRC CAT > 1 mg/L; 30
minutes contact time at avg
flow or 20 minutes at peak
flow
10 mg/L (mon avg)
or CBOD5
8 mg/L (mon avg)
NS
2 NTU (daily avg)
CAT > 5 NTU
Fecal coliform:
-14/1 OOmL (mon geom),
CAT > 49/1 OOmL
E. coli:
-11/1 OOmL (mon geom), CAT
> 35/1 OOmL
Enterococci:
-11/1 OOmL (mon geom),
CAT > 24/1 OOmL
NS
NS
-
Oxidized, coagulated, filtered,
disinfected
NWRI UV Guidelines
Chlorine residual > 1;
30 minutes contact time
30 mg/L
30 mg/L
-2 NTU (avg)
-5 NTU (max)
Total coliform:
-2.2/1 OOmL (7-d med)
-23/1 OOmL (max)
NS
NS
Specific reliability and
redundancy requirements
based
on formal assessment
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.
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-10 Agricultural reuse - non-food crops and processed food crops (where permitted)
Secondary
treatment,
disinfection
Secondary
treatment, with or
without disinfection
Secondary
treatment, basic
disinfection
Secondary-23:
oxidized, disinfected
Filtration
(or equivalent)
Secondary treatment,
disinfection
Secondary treatment1
Oxidized, disinfected
UVdose,
if UV disinfection used
75 mJ/cm2
at max day flow
NWRI UV Guidelines
TRC CAT < 1 mg/L; 30
minutes contact time at
avg flow or 20 minutes at
peak flow
TRC > 0.5 mg/L; 15
minutes contact time
at peak hr flow1
Chlorine residual > 5
mg/L; 10 minutes actual
modal contact time
Chlorine residual > 1
mg/L; 15 minute contact
time at peak hr flow
Chlorine residual
> 1 mg/L; 30 minutes
Chlorine disinfection
requirements, if used
30 mg/L (mon avg)
-45 mg/L (max wk)
CBODs:
20 mg/L (ann avg)
30 mg/L (mon avg)
-45 mg/L (wk avg)
-60 mg/L (max)
Without pond: 20 mg/L
(orCBOD515mg/L)
30 mg/L or 60 mg/L
depending on design flow
-10 mg/L (mon avg)
15 mg/L (daily max)
30 mg/L (30-d avg)
orCBOD5
25 mg/L (mon avg)
-40 mg/L (max wk)
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
-5 mg/L (mon avg)
10 mg/L (daily max)
30 mg/L (mon avg)
-45 mg/L (max wk)
30 mg/L (30-d avg)
Fecal coliform:
200/100m L (mon geom),
CAT > 800/100m L
Fecal coliform or £. coli:
200/100m L (30-d geom)
-800/1 OOmL (max)
Fecal conform:
-23/1 OOmL (7-day med)
-200/1 OOmL (not more
than one sample exceeds
this value in 30 d)
Fecal coliform:
200/1 OOmL in last 4
of 7 samples
-800/1 OOmL (max)
Fecal coliform:
-1000/100m Lin last
4 of 7 samples
-4000/1 OOmL (max)
Fecal coliform:
-200/1 OOmL (avg)
-800/1 OOmL (max)
Fecal coliform:
200/1 OOmL (mon geom)
-400/1 OOmL (wk geom)
Fecal coliform or £ coli:
-14/1 OOmL (mon mean)
-25/1 OOmL (daily max)
£ coli:
126/1 OOmL (mon geom),
CAT > 235/1 OOmL
Total coliform:
-23/1 OOmL (7-d med)
-240/1 OOmL (max)
Bacterial indicators
Enterococci:
-35/1 OOmL (30-d geom)
-89/1 OOmL (max)
Enterococci:
-35/1 OOmL (mon geom),
CAT > 104/1 OOmL
If nitrogen > 10 mg/L,
special requirements
may be mandated to
protect qroundwater
If nitrogen > 10 mg/L,
special requirements
may be mandated to
protect qroundwater
Ammonia as NHs-N
-4 mg/L (mon avg)
-6 mg/L (daily max)
(NH3-N + N03-N):
< 10 mg/L (max)
NS = not specified by the state's reuse regulation
In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the
concentration of fecal coliform prior to disinfection: is < 1,000 cfu per 100 mL, the CrT shall be 25 mg-min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg-min/L; and is > 10,000 cfu per 100 mL the CrT shall be 120 mg-min/L.
Nevada prohibits public access and requires a minimum buffer zone of 800 feet for spray irrigation of non-food crops. (Category E, NAC 445A.2771).
2012 Guidelines for Water Reuse
4-29
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Chapter 4 State Regulatory Programs for Water Reuse
Table 4-11 Impoundments - unrestricted
Unit processes
Arizona
Class A
Secondary treatment,
disinfection
California
Disinfected Tertiary
Oxidized, coagulated,
filtered, disinfected2
Florida
Hawaii
New Jersey
North Carolina
Texas
Type I
Virginia
Level 1
Secondary treatment,
filtration, high-level
disinfection
Washington
Class A
Oxidized, coagulated,
filtered and disinfected
UV dose,
if UV disinfection used
NWRI UV Guidelines
A/S
NWRI UV Guidelines
Chlorine disinfection
requirements, if used
CrT > 450 mg min/L;
90 minutes modal
contact time at peak
dry weather flow
A/S
TRC CAT < 1 mg/L after
minimum contact time of
SOmins
at avg flow or 20 minsat
peak flow
Chlorine residual >
1 mg/L; 30 minutes
contact time
A/S
5 mg/L
10 mg/L (mon avg)
orCBODs:
8 mg/L (mon avg)
30 mg/L
NR
A/S
NS
A/S
30 mg/L
-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
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
-23/100m L (max)
Total coliform:
-2.2/1 OOmL (7-day med)
-23/1 OOmL (not more than
one sample exceeds this
value in 30 d)
-240/1 OOmL (max)
NR
NR
NP
NR
NS
Fecal coliform or E.coli:
-20/1 OOmL (avg)
-75/1 OOmL (max)
Enterococci:
-4/1 OOmL (avg)
-9/1 OOmL (max)
Fecal coliform:
-14/1 OOmL (mongeom),
CAT > 49/1 OOmL
£. co/;V
-11/1 OOmL (mongeom),
CAT > 35/1 OOmL
Enterococci:
-11/1 OOmL (mongeom),
CAT > 24/1 OOmL
Total coliform:
-2.2/1 OOmL (7-day med)
-23/1 OOmL (max)
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
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 forsnowmaking, 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.
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-12 Impoundments - restricted
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
Unit processes
UV dose,
if UV disinfection used
Chlorine disinfection
requirements, if used
BOD5
TSS
Turbidity
Bacterial indicators
Other
Secondary treatment,
disinfection
A/S
A/S
A/S
A/S
A/S
Fecal coliform:
-200/1 00m Lin last 4 of
7 samples
-800/1 OOmL (max)
If nitrogen > 10 mg/L,
special requirements
may be mandated to
protect groundwater
Oxidized, disinfected
A/S
A/S
A/S
A/S
A/S
Total coliform:
-2.2/100ml_(7-dmed)
-23/1 00 (not more than
one sample exceeds
this value in 30 d)
NR
NR
NR
NR
NR
NR
NR
-
Oxidized, disinfected
A/S
Chlorine residual > 5 mg/L;
actual modal contact time of
10 minutes
30 mg/L or 60 mg/L
depending on design flow
30 mg/L or 60 mg/L
depending on design flow
A/S
Fecal coliform:
-23/1 OOmL (7-day med)
-200/1 OOmL (not more than
one sample exceeds this
value in 30 d)
Secondary treatment,
disinfection
A/S
A/S
30 mg/L (30-d avg)
30 mg/L (30-d avg)
A/S
Total coliform:
-2.2/1 OOmL (30-d geom)
-23/1 OOmL (max)
NR
NR
NR
NR
NR
NR
NR
NR
A/S
A/S
A/S
A/S
A/S
A/S
A/S
-
A/S
A/S
A/S
Without pond: 20 mg/L
(orCBOD515mg/L)
With pond: 30 mg/L
A/S
A/S
Fecal coliform or E. coli:
-200/1 OOmL (30-d geom)
-800/1 OOmL (max)
Enterococci:
-35/1 OOmL (30-d geom)
-89/1 OOmL (max)
Secondary treatment,
disinfection
A/S
TRC CAT < 1 mg/L
after minimum contact
time of 30 mins at avg
flow or 20 mins at
peak flow
30 mg/L (mon avg)
45 mg/L (max wk)
orCBODs:
25 mg/L (mon avg)
40 mg/L (max wk)
30 mg/L (mon avg)
45 mg/L (max wk)
A/S
Fecal coliform:
-200/1 OOmL (mon
geom),
CAT > 800/1 OOmL
E. coli:
-126/1 OOmL (mon
geom),
CAT > 235/1 OOmL
Enterococci:
-35/1 OOmL (mon
geom), CAT >
104/1 OOmL
Oxidized, disinfected
NWRI UV Guidelines
Chlorine residual >
1 mg/L; 30 minutes
contact time
30 mg/L
30 mg/L
NS
Total coliform:
-2.2/1 OOmL (7-d med)
-23/1 OOmL (max)
Specific reliability
and redundancy
requirements based on
formal assessment
NS = not specified by the state's reuse regulation; NR = not regulated by the state under the reuse program; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements
2012 Guidelines for Water Reuse
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Chapter 4 State Regulatory Programs for Water Reuse
Table 4-13 Environmental reuse
Hfv^^l
BsB 1 Unit processes
n
KK=| UVdose,
9jj3 it UV disinfection used
KU 1 Chlorine disinfection
1 requirements, if used
1 BODs
1 (or CBODs)
•=•
EH
HTSS
^E^H 1
H
•£• Bacterial indicators
BSB
H
1 Total Ammonia
KB
El
B^l Nutrients
n
^^K*^H
H
i
Arizona1 1 California
A/R
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
Secondary treatment,
nitrification, basic
disinfection
A/S
TRC>0.5mg/L;15
minutes contact time at
peak hr flow3
CBODs:
-5 mg/L (ann avg)
-6.25 mg/L (mon avg)
-7.5 mg/L (wk avg)
-10 mg/L (max)
-5 mg/L (ann avg)
-6.25 mg/L (mon avg)
-7.5 mg/L (wk avg)
-10 mg/L (max)
Fecal coliform:
-200/1 OOmL (avg)
-800/1 00m L (max)
-2 mg/L (ann avg)
-2 mg/L (mon avg)
-3 mg/L (wk avg)
-4 mg/L (max)
Phosphorus:
-1 mg/L (ann avg)
-1 .25 mg/L (mon avg)
-1 .5 mg/L (wk avg)
-2 mg/L (max)
Nitrogen:
-3 mg/L (ann avg)
-3.75 mg/L (mon avg)
-4.5 mg/L (wk avg)
-6 mg/L (max)
A/R
NR
NR
NR
NR
NR
NR
NR
CatTc ' NewJerse North Carolina 1 ^ ^ ^ 1 Washington
Secondary treatment,
disinfection
A/S
A/S
30 mg/L (30-d avg)
30 mg/L (30-d avg)
Fecal coliform:
-23/1 OOmL (30-d geom)
-240/1 OOmL (max)
A/S
A/S
^M
NR
NR
NR
NR
NR
NR
NR
Filtration
(or equivalent)
A/S
A/S
-10 mg/L (mon avg)
-15 mg/L (daily max)
-5 mg/L (mon avg)
-10 mg/L (daily max)
Fecal coliform or £. co//:
-14/1 OOmL (mon mean)
-25/1 OOmL (daily max)
Ammonia as NHs-N:
-4 mg/L (mon avg)
-6 mg/L (daily max)
Phosphorus:
1 mg/L (max)6
Nitrogen:
4 mg/L (max)6
A/R
NR
NR
NR
NR
NR
NR
NR
^M
A/S
A/S
A/S
A/S
A/S
A/S
A/S
Oxidized, coagulated,
filtered, disinfected
NWRI UV Guidelines
Chlorine residual >
1 mg/L; 30 minutes
contact time
20 mg/L
20 mg/L
Total coliform:
-2.2/1 OOmL (7-dmed)
-23/1 OOmL (max)
Not to exceed chronic
standards for freshwater
Phosphorus:
1 mg/L (ann avg)6
A/S = nof 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."
Florida requirements are for a natural receiving wetland regulated under Florida Administrative Code Chapter 62-611 for Wetlands Application.
In Florida when chlorine disinfection is used, the product of the total chlorine residual and contact time (CrT) at peak hour flow is specified for three levels of fecal coliform as measured prior to disinfection. (See Section 6.4.3.1 for further discussion of CrT.) If the
concentration of fecal coliform prior to disinfection: is < 1,000 cfu per 100 mL, the CrT shall be 25 mg-min/L; is 1,000 to 10,000 cfu per 100 mL the CrT shall be 40 mg-min/L; and is > 10,000 cfu per 100 mL the CrT shall be 120 mg-min/L.
Wetlands in Virginia, whether natural or created as mitigation for impacts to existing wetlands, are considered state surface waters; release of reclaimed water into a wetland is regulated as a point source discharge and subject to applicable surface water quality
standards of the state.
These limits are not to be exceeded unless net environmental benefits are provided by exceeding these limits.
The phosphorous limit is as an annual average for wetland augmentation/restoration while for stream flow augmentation is the same as that required to NPDES discharge limits, or in other words variable.
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-14 Industrial reuse1
I Arizona2 DisinSdTertiary
Hfv^^l
KJB 1 Unit processes
Bjjvjfl UVdose,
PfflJ if UV disinfection used
KfJEfl
1 " 1
•=• 1 Chlorine disinfection
KM 1 requirements, if used
•9
1 BODs
• (orCBODs)
H
•^•1 Turbidity
Bj>H Bacterial indicators
•
1 Pathogens
Individual Reclaimed
Water Permit,
case-specific2
NS
NS
NS
NS
NS
NS
NS
Oxidized, coagulated,
filtered, disinfected
NWRI UV Guidelines
CrT > 450 mg-min/L:
90 minutes modal
contact time at peak dry
weather flow
NS
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
Total coliform:
-2.2/1 OOmL (7-day med)
-23/1 OOmL (not more than
one sample exceeds this
value in 30 d)
-240/1 OOmL (max)
NS
Hawaii1
Florida3 R-2 Water
Secondary treatment,
filtration, high-level
disinfection
NWRI UV Guidelines
enforced, variance allowed
TRC > 1 mg/L;
15 minutes contact time at
peak hr flow4
CBODs:
-20 mg/L (ann avg)
-30 mg/L (mon avg)
-45 mg/L (wk avg)
-60 mg/L (max)
5 mg/L (max)
Case-by-case
(generally 2 to 2.5 NTU)
Florida requires
continuous on-line
monitoring of turbidity as
indicator for TSS
Fecal coliform:
-75% of samples
below detection
-25/1 OOmL (max)
G/aref/a, Ctyptosporidium
sampling once each 2-yr
period if high-level
disinfection is required
Oxidized, disinfected
NS
Chlorine residual > 5 mg/L,
actual modal contact time of
10 minutes
30 mg/L or 60 mg/L
depending on design flow
30 mg/L or 60 mg/L
depending on design flow
NS
Fecal coliform:
-23/1 OOmL (7-day med)
-200/1 OOmL (not more than
one sample exceeds this
value in 30 d)
NS
Nevada New Jersey North Carolina Texas1'5 Virginia6 Washington5
Category E Type IV RWBR Type 1 Type II Level 2 Class A
Secondary treatment,
disinfection
NS
NS
30 mg/L (30-d avg)
30 mg/L (30-d avg)
NS
Fecal coliform:
-2.2/1 OOmL (30-d geom)
-23/1 OOmL (max)
TR
Case-by-case
NS
NS
NS
Case-by-case
NS
NS
NS
Filtration (or equivalent),
unless there is no
public access or employee
exposure
NS
NS
-10 mg/L (mon avg)
-15 mg/L (daily max)
-5 mg/ (mon avg)
-10 mg/L (daily max)
10 NTU (max)
Fecal coliform or E. coli:
-14/1 OOmL (mon mean)
-25/1 OOmL (daily max)
NS
NS
NS
NS
Without pond: 20 mg/L (or
CBOD515mg/L)
With pond: 30 mg/L
NS
NS
Fecal coliform or E. coli:
-200/1 OOmL (30-d geom)
-800/1 OOmL (max)
Enterococci:
-35/1 OOmL (30-d geom)
-89/1 OOmL (max)
NS
Secondary treatment,
disinfection
NS
TRC CAT < 1 mg/L:
30 minutes contact time at
avg flow or 20 minutes at
peak flow
-30 mg/L (mon avg)
-45 mg/L (max wk)
or CBODs
-25 mg/L (mon avg)
-40 mg/L (max wk)
-30 mg/L (mon avg)
-45 mg/L (max wk)
NS
Fecal coliform:
-200/1 OOmL (mon goem),
CAT > 800/1 OOmL
E. coli:
126/1 OOmL (mon geom),
CAT > 235/1 OOmL
Enterococci:
-35/1 OOmL (mon geom)
-CAT > 104/1 OOmL
NS
Oxidized, coagulated,
filtered and disinfected
NWRI UV Guidelines
Chlorine residual >
1 mg/L: 30 minutes
contact time
30 mg/L
30 mg/L
-2 NTU (avg)
-5 NTU (max)
Total coliform:
-2.2/1 OOmL (7-d med)
-23/1 OOmL (max)
NS
NS = not specified by the state's reuse regulation; NR = not regulated by the state under the reuse program; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements
1 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.
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Chapter 4 State Regulatory Programs for Water Reuse
Table 4-15 Groundwater recharge - nonpotable reuse1
Aquifer Storage and
Recovery in accordance
with G.S. 143-214.2.
Oxidized, coagulated,
filtered, nitrogen
reduced, disinfected
Regulated by Aquifer
Protection Permit2
Secondary treatment,
basic disinfection
UV dose,
if UV disinfection used
NWRI UV Guidelines
TRC > 0.5 mg/L;
15 minutes contact time
at peak hr flow4
Chlorine residual > 1
mg/L 30 minutes contact
time at peak hr flow
Chlorine disinfection
requirements, if used
CBODs:
-20 mg/L (ann avg)
-30 mg/L (mon avg)
-45 mg/L (wk avg)
-60 mq/L (max)
BODs
(or CBODs)
-20 mg/L (ann avg)
-30 mg/L (mon avg)
-45 mg/L (wk avg)
-60 mg/L (max)
Fecal conform:
-200/100m L (avg)
-800/1 OOmL (max)
Total conform:
2.2/1 OOmL (7-d med)
23/1 OOmL (max day)
Bacterial indicators
NS (nitrate < 12 mg/L)
Primary and Secondary
Drinking Water Standards
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
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 etseq. 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).
4-34
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Chapter 4 | State Regulatory Programs for Water Reuse
Table 4-16 Indirect potable reuse (IPR)
Arizona
California
Florida'
New North
Hawaii Nevada Jersey7 Carolina
Texas
Virginia
Washington
Surface Percolation Direct Groundwater Recharge8 Streamflow Augmentation
Class A Class A Case-by-case
1
Unit processes
1 UVdose,
1 if UV disinfection used
1
• Chlorine disinfection
1 requirements, if used
•
1 Rorv
1 (orCBODs)
1
1 TSS
1
1 Turbidity
1 Bacterial indicators
1
1 Total Nitrogen
1 TOC
1 Primary and Secondary
1 Drinking Water Standards
1 Pathogens
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
Oxidized, coagulated,
filtered, disinfected, multiple
barriers for pathogen and
organics removal
NWRI Guidelines3
CrT > 450 mg min/L;
90 minutes modal
contact time at peak dry
weather flow3
NS
NS
-2 NTU (avg) for
-10NTU(max)for
media filters
-0.2 NTU (avg) for
membrane filters
-0.5 NTU (max) for
membrane filters
Total coliform:
-2.2/1 OOmL (7-day med)
-23/1 OOmL (not more than
one sample exceeds
this value in 30 d)
-240/1 OOmL (max)
10mg/l (avg of 4
consecutive samples)
0.5 mg/L
Compliance with most
primary and secondary
TR
Secondary treatment, filtration,
high-level disinfection, multiple
barriers for pathogen and
organics removal
NWRI UV Guidelines enforced,
variance allowed
TRC>1 mg/L; 15 minutes
contact time at peak hr flow6
CBODs:
-20 mg/L (ann avg)
-30 mg/L (mon avg)
-45 mg/L (wk avg)
-60 mg/L (max)
5 mg/L (max)
Case-by-case
(generally 2 to 2.5 NTU) Florida
requires continuous on-line
monitoring of turbidity as
indicator for TSS
Total coliform:
-4/1 OOmL (max)
10 mg/L (ann avg)
-3 mg/L (mon avg)
-5 mg/L (max);
TOX6:
< 0.2 (mon avg) or 0.3 mg/L
(max); alternate limits allowed
Compliance with most primary
and secondary
Giardia, Cryptosporidium
sampling quarterly
Case-by-case
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
Case-by-case
NS
NS
5 mg/L
NS
3 NTU
Fecal coliform
or £ co//
-20/1 OOmL
(30-d geom)
-75/1 OOmL
(max)
Enterococci
-4/1 OOmL (30-
d geom)
-9/1 OOmL
(max)
NS
NS
NS
NS
Case-by-case
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
Oxidized with nitrogen
reduction, filtered,
NWRI Guidelines
Chlorine residual
> 1 mg/L; 30 minutes
contact time at
peak hr flow
30 mg/L
30 mg/L
-2 NTU (avg)
-5 NTU (max)
Total coliform:
-2. 2/1 00 (7 -d med)
-23/1 00 (max)
NA
NA
Compliance with
SDWA MCLs
NS
Oxidized, coagulated, filtered,
RO-treated, disinfected
NWRI Guidelines
Chlorine residual
> 1 mg/L; 30 minutes contact
time at
peak hr flow
5 mg/L
5 mg/L
-0.1 NTU (avg)
-0.5 NTU (max)
Total coliform:
-1/1 OOmL (avg)
-5/1 OOmL (max)
10 mg/L
1 mg/L
Compliance with most primary
and secondary
NS
Oxidized, clarified,
disinfected
NWRI Guidelines
Chlorine residual to comply
with NPDES permit
30 mg/L
30 mg/L
NS
Fecal coliform:
-200/1 OOmL (avg)
-400/1 OOmL (max wk)
NPDES requirements to
receiving stream
NS
NPDES requirements to
receiving stream
NS
NS = not specified by the state's reuse regulation; NR = not regulated by the state under the reuse program; ND = regulations have not been developed for this type of reuse; TR = monitoring is not required but virus removal rates are prescribed by treatment requirements
2012 Guidelines for Water Reuse
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Chapter 4 State Regulatory Programs for Water Reuse
1 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, 201 1 ) .
3 Additional pathogen removal is required for groundwater recharge through other treatment processes in order to achieve 1 2 log enteric virus reduction, 1 0 log Giardia cyst reduction, and 1 0 log Cryptosporidium oocysts reduction.
4 Florida requirements are for the planned use of reclaimed water to augment Class F-l, G-l or G-ll groundwaters (US drinking water sources) with a background TDS of 3,000 mg/L or less. For G-ll 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 (1 50 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 1 00 ml, the CrT shall be 25 mg-min/L; is 1 ,000 to 1 0,000 cfu per 1 00 ml the CrT shall be 40 mg-min/L; and is > 1 0,000 cfu per 1 00 ml the CrT shall be 1 20 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.
Washington requires the minimum horizontal
being withdrawn as a drinking water supply.
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 (61 0 meters) and must be retained underground for a minimum of 1 2 months prior to
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Chapter 4 State Regulatory Programs for Water Reuse
4.6 References
Anderson, P., N. Denslow, J. E. Drewes, A. Olivieri, D.
Schlenk, and S. Snyder. 2010. Final Report Monitoring
Strategies for Chemicals of Emerging Concern (CECs) in
Recycled Water Recommendations of a Science Advisory
Panel. SWRCB. Sacramento, CA.
California Department of Public Health (CDPH), 2011. Draft
Regulations for Groundwater Replenishment with Recycled
Water, November 21, 2011. Retrieved August, 2012 from
.
Crook, J. 2010. NWRI White Paper: Regulatory Aspects of
Direct Potable Reuse in California. National Water Research
Food and Agriculture Organization of the United Nations
(FAO). 1985. FAO Irrigation and Drainage Paper, 29 Rev. 1.
Food and Agriculture Organization of the United Nations:
Rome, Italy.
Huffman, D.E., A. L. Gennaccaro, T. L. Berg, G. Batzer, and
G. Widmer. 2006. "Detection of infectious parasites in
reclaimed water." Water Environment Research.
78(12):2297-302.
National Research Council (NRC). 2012. Water Reuse:
Potential for Expanding the Nation's Water Supply Through
Reuse of Municipal Wastewater. The National Academies
Press: Washington, D.C.
National Water Research Institute (NWRI). 2012. Ultraviolet
Disinfection Guidelines for Drinking Water and Water Reuse,
3rd Edition. National Water Research Institute. Fountain
Valley, CA.
National Water Research Institute (NWRI). 2003. Ultraviolet
Disinfection Guidelines for Drinking Water and Water Reuse,
2nd Edition. National Water Research Institute. Fountain
Valley, CA.
National Water Research Institute (NWRI). 2000. Ultraviolet
Disinfection Guidelines for Drinking Water and Water Reuse.
National Water Research Institute. Fountain Valley, CA.
U.S. Environmental Protection Agency (EPA). 2004.
Guidelines for Water Reuse. EPA. 625/R04/108.
Environmental Protection Agency. Washington, D.C.
WateReuse Association. 2009. How to Develop a Water
Reuse Program: Manual of Practice, WRA-105. WateReuse
Association. Alexandria, VA.
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4-38 2012 Guidelines for Water Reuse
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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.
Domestic self-
supply
1%
Livestock
1%
Mining
1%
quaculture
2%
Industrial
4%
Figure 5-1
Freshwater use by category in the United States
(Source: Kenny et al., 2009)
Treated municipal wastewater represents a significant
potential source of reclaimed water. As a result of the
Federal Water Pollution Control Act Amendments of
1972, the CWA of 1977 and its subsequent
amendments, centralized wastewater treatment has
become commonplace in urban areas of the United
States. Within the United States, the population
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
2012 Guidelines for Water Reuse
5-1
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Chapter 5 | Regional Variations in Water Reuse
wastewater collection and treatment systems will also
increase, creating significant opportunities to
implement reclaimed water systems to augment water
supplies and, in many cases, improve the quality of
surface waters.
A key issue nationally in water reuse is the existing
potable water rates. Low potable water rates typically
make water reuse less favorable. A comparison of
potable and reclaimed water rates is provided in Table
7-1.
5.1.2 Examples of Reuse in the United
States
High water demand areas might benefit by augmenting
existing water supplies with reclaimed water. Arid
regions of the United States (such as the Southwest)
are natural candidates for water reclamation, and
significant reclamation projects are underway
throughout this region. Yet, arid regions are not the
only viable candidates for water reuse. As shown in
Figure 5-2, water reuse is practiced widely throughout
much of the United States, according to a survey
conducted for this document. While the survey of
reuse locations is not exhaustive, the information
collected is meant to illustrate how widespread water
reuse is in the United States. Data sources consulted
for this survey included:
• WRA database of water reuse installations
• California SWRCB inventory of reuse projects in
California, available online (SWRCB, 2011)
• FDEP inventory of reuse projects in Florida,
available online (FDEP, 2012a)
• Tennessee water reuse survey provided online
by Tennessee Tech University (TTU) for years
2006 to 2011 (TTU, 2012)
• TCEQ list of reuse installations
• North Carolina Department of Environment and
Natural Resources Division of Water Quality
inventory of reuse installations
• 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.
5-2
2012 Guidelines for Water Reuse
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Chapter 5 | Regional Variations in Water Reuse
Legend
Case Studl&fl by Category
141 Er.-«lronrnenta) Reuse ano Irrpc unorrenfc
i5i PcGi&e Reuse
Ml3-Waroc
MW*wt ard &-cat Laft
Mowlams ana Pans
eas1 South :--•-
c htofth*«t ScumeaK
Figure 5-2
Geographic Display of United States
Reuse Case Studies Categorized by Application
2012 Guidelines for Water Reuse
5-3
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Chapter 5 | Regional Variations in Water Reuse
Figure 5-2 Legend
Map Code 1 Text code 1 Case Study Name
AZ-1
AZ-2
AZ-3
AZ-4
AZ-5
AZ-6
AZ-7
CA-1
CA-2
CA-3
CA-4
CA-5
CA-6
CA-7
CA-8
CA-9
CA-10
CA-11
CA-1 2
CA-1 3
CA-1 4
CA-1 5
CA-1 6
CO-1
CO-2
CO-3
CO-4
CO-5
CO-6
DC-1
FL-1
FL-2
FL-3
FL-4
FL-5
FL-6
FL-7
FL-8
US-AZ-Gilbert
US-AZ-Tucson
US-AZ-Sierra Vista
US-AZ-Phoenix
US-AZ-Blue Ribbon Panel
US-AZ-Prescott Valley
US-AZ-Frito Lay
US-CA-Psychology
US-CA-San Ramon
US-CA-San Diego
US-CA-Orange County
US-CA-North City
US-CA-Santa Cruz
US-CA-Monterey
US-CA-Southern California MWD
US-CA-Los Angeles County
US-CA-Elsinore Valley
US-CA-Temecula
US-CA-Santa Ana River
US-CA-VanderLans
US-CA- Pasteurization
US-CA-Regulations
US-CA-West Basin
US-CO-Denver Zoo
US-CO-Denver
US-CO-Denver Energy
US-CO-Denver Soil
US-CO-Sand Creek
US-CO-Water Rights
US-DC-Sidwell Friends
US-FL-Miami So District Plant
US-FL-Pompano Beach
US-FL-Orlando E. Regional
US-FL-Economic Feasibility
US-FL-Reedy Creek
US-FL-Marco Island
US-FL-Everglade City
US-FL-Orlando Wetlands
Town of Gilbert Experiences Growing Pains in Expanding the
Reclaimed Water System
Tucson Water: Developing a Reclaimed Water Site Inspection
Program
Environmental Operations Park
91st Avenue Unified Wastewater Treatment Plant Targets 100
Percent Reuse
Arizona Blue Ribbon Panel on Water Sustainability
Effluent Auction in Prescott Valley, Arizona
Frito-Lay Process Water Recovery Treatment Plant, Casa Grande,
Arizona
The Psychology of Water Reclamation and Reuse: Survey Findings
and Research Roadmap
Managing a Recycled Water System through a Joint Powers
Authority: San Ramon Valley
City of San Diego - Water Purification Demonstration Project
Groundwater Replenishment System, Orange County, California
EDR at North City Water Reclamation Plant
Water Reuse Study at the University of California Santa Cruz
Campus
Long-term Effects of the Use of Recycled Water on Soil Salinity
Levels in Monterey County
Metropolitan Water District of Southern California's Local Resource
Program
Montebello Forebay Groundwater Recharge Project using
Reclaimed Water, Los Angeles County, California
Recycled Water Supplements Lake Elsinore
Replacing Potable Water with Recycled Water for Sustainable
Agricultural Use
Water Reuse in the Santa Ana River Watershed
Leo J. Vander Lans Water Treatment Facility
Use of Pasteurization for Pathogen Inactivation for Ventura Water,
California
California State Regulations
West Basin Municipal Water District: Five Designer Waters
Denver Zoo
Denver Water
Xcel Energy's Cherokee Station
Effects of Recycled Water on Soil Chemistry
Sand Creek Reuse Facility Reuse Master Plan
Water Reuse Barriers in Colorado
Smart Water Management at Sidwell Friends School
South District Water Reclamation Plant
City of Pompano Beach OASIS
Eastern Regional Reclaimed Water Distribution System
Economic Feasibility of Reclaimed Water to Users
Reuse at Reedy Creek Improvement District
Marco Island, Florida, Wastewater Treatment Plant
Everglade City, Florida
City of Orlando Manmade Wetlands System
5-4
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Chapter 5 Regional Variations in Water Reuse
Figure 5-2 Legend
Map Code 1 Text code
FL-9
FL-10
FL-11
FL-12
GA-1
GA-2
GA-3
HI-1
MA-1
MA- 2
MA- 3
ME-1
MN-1
NC-1
NY-1
PA-1
PA-2
TN-1
TX-1
TX-2
TX-3
TX-4
TX-5
VA-1
VA-2
WA-1
WA-2
WA-3
WA-4
US-FL-SWFWMD Partnership
US-FL-Altamonte Springs
US-FL-Clearwater
US-FL-Turkey Point
US-GA-Clayton County
US-GA-Forsyth County
US-GA-Coca Cola
US-HI-Reuse
US-MA-Southborough
US-MA-Hopkinton
US-MA-Gillette Stadium
US-ME-Snow
US-MN-Mankato
US-NC-Cary
US-NY-PepsiCo
US-PA-Kutztown
US-PA-Mill Run
US-TN-Franklin
US-TX-San Antonio
US-TX-Big Spring
US-TX-Landscape Study
US-TX-NASA
US-TX-Wetlands
US-VA-Occoquan
US-VA-Regulation
US-WA-Sequim
US-WA-Regulations
US-WA-King County
US-WA-Yelm
E^SEsm^^^^mm^^m^^m
Regional Reclaimed Water Partnership Initiative of the Southwest
Florida Water Management District
The City of Altamonte Springs: Quantifying the Benefits of Water
Reuse
Evolution of the City of Clearwater's Integrated Water Management
Strategy
Assessing Contaminants of Emerging Concern (CECs) in Cooling
Tower Drift
Sustainable Water Reclamation Using Constructed Wetlands: The
Clayton County Water Authority Success Story
On the Front Lines of a Water War, Reclaimed Water Plays a Big
Role in Forsyth County, Georgia
Recovery and Reuse of Beverage Process Water
Reclaimed Water Use in Hawaii
Sustainability and LEED Certification as Drivers for Reuse: Toilet
Flushing at The Fay School
Decentralized Wastewater Treatment and Reclamation for an
Industrial Facility, EMC Corporation Inc., Hopkinton, Massachusetts
Sustainability and Potable Water Savings as Drivers for Reuse:
Toilet Flushing at Gillette Stadium
Snowmaking with Reclaimed Water
Reclaimed Water for Peaking Power Plant: Mankato, Minnesota
Town of Gary, North Carolina, Reclaimed Water System
Identifying Water Streams for Reuse in Beverage Facilities: PepsiCo
ReCon Tool
The Water Purification Eco-Center
Zero-Discharge, Reuse, and Irrigation at Fallingwater, Western
Pennsylvania Conservancy
Franklin, Tennessee Integrated Water Resources Plan
San Antonio Water System Water Recycling Program
Raw Water Production Facility: Big Spring Plant
Site Suitability for Landscape Use of Reclaimed Water in the
Southwest
U.S. Water Recovery System on the International Space Station
East Fork Raw Water Supply Project: A Natural Treatment System
Success Story
Potable Water Reuse in the Occoquan Watershed
Water Reuse Policy and Regulation in Virginia
City of Sequim's Expanded Water Reclamation Facility and Upland
Reuse System
Washington State Regulations
Demonstrating the Safety of Reclaimed Water for Garden
Vegetables
City of Yelm, Washington
2012 Guidelines for Water Reuse
5-5
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Chapter 5 | Regional Variations in Water Reuse
Mountains and Plains: (EPA Region 8) Colorado,
Montana, South Dakota, North Dakota, Utah, and
Wyoming.
Pacific Southwest: (EPA Region 9) Arizona,
California, Hawaii, Nevada, U.S. Pacific Insular Area
Territories (Territory of Guam, Territory of American
Samoa, and the Commonwealth of the Northern
Mariana Islands (CNMI), and 147 federally recognized
tribal nations.
Pacific Northwest: (EPA Region 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.
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Chapter 5 Regional Variations in Water Reuse
Table 5-1 Percent change in resident population
and 1990-2010 (USCB, n.d.)
• state or Region 1
United States
NORTHEAST REGION
Connecticut
Maine
Massachusetts
New Hampshire
Rhode Island
Vermont
New Jersey
New York
MID-ATLANTIC REGION
Delaware
District of Columbia
Maryland
Pennsylvania
Virginia
West Virginia
SOUTHEAST REGION
Alabama
Florida
Georgia
Kentucky
Mississippi
North Carolina
South Carolina
Tennessee
MIDWEST AND GREAT LAKES REGION
Illinois
Indiana
Michigan
Minnesota
Ohio
Wisconsin
Iowa
Kansas
Missouri
Nebraska
in each
'a chang
990-200
13.2
6,
3.6
3.8
5.5
11.4
4.5
8.2
8.9
5.5
7.3
17.6
-5.7
10.8
3.4
14.4
0.8
19.1
10.1
23.5
26.4
9.7
10.5
21.4
15.1
16.7
8.0
8.6
9.7
6.9
12.4
4.7
9.6
5.4
8.5
9.3
8.4
region during the periods
0 2000-2010
9.7
^^ «
4.9
4.2
3.1
6.5
0.4
2.8
4.5
2.1
7.2
14.6
5.2
9.0
3.4
13.0
2.5
14.7
7.5
17.6
18.3
7.4
4.3
18.5
15.3
11.5
3.9
3.3
6.6
-0.6
7.8
1.6
6.0
4.1
6.1
7.0
6.7
1990-2000,2000-2010,
• % change ^H
1990-2010 ^1
24.1
9.5
8.7
8.2
8.8
18.7
4.9
11.2
13.7
7.7
15.1
34.8
-0.9
20.7
6.9
29.3
3.3
36.6
18.3
45.3
49.5
17.7
15.3
43.9
32.7
30.1
12.2
12.2
16.9
6.3
21.2
6.4
16.3
9.7
15.2
17.0
15.7
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Chapter 5 | Regional Variations in Water Reuse
Table 5-1 Percent change in resident population in each region during the periods 1990-2000, 2000-2010,
and 1990-2010 (USCB, n.d.)
State or Region
SOUTH CENTRAL REGION
Arkansas
% change
1990-2000
17.9
13.7
% change
2000-2010
15.5
9.1
% change
1990-2010
36.1
24.0
Louisiana
5.9
1.4
7.4
New Mexico
20.1
13.2
35.9
Oklahoma
9.7
19.3
Texas
Colorado
30.6
20.6
16.1
16.9
48.0
42.4
52.7
Montana
12.9
9.7
North Dakota
0.5
4.7
5.3
South Dakota
7.9
17.0
Utah
29.6
60.4
Wyoming
PACIFIC SOUTHWEST REGION
Arizona
18.1
40.0
14.1
24.6
24.3
33.5
74.4
California
10.0
25.2
Hawaii
9.3
12.3
22.7
Nevada
66.3
35.1
124.7
Alaska
14.0
13.3
29.1
Idaho
28.5
21.1
55.7
Oregon
20.4
12.0
Washington
21.1
14.1
38.2
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Chapter 5 Regional Variations in Water Reuse
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.
Northeast Region
lUS
Population
Land Use
Figure 5-3
Percent change in population (2000-2010) and
developed land (1997-2007) in the Northeast Region,
compared to the United States
While the percent population change in the Northeast
has lagged behind other regions, the developed land
percent change in the Northeast has outpaced the
United States average.
5.2.1.2 Precipitation and Climate
The most significant impediment to reuse is the prolific
amount of annual precipitation in the Northeast. The
annual average precipitation is approximately 42 in
(106.5 cm), with monthly precipitation between 3 in
(7.5 cm) and 4 in (10 cm). The annual average
temperature in the region is approximately 53 degrees
F (11.6 degrees C). The region's high precipitation and
low annual temperature, combined with a lower than
average water evaporation rate, results in an
abundance of water for recharge of water resources
on a regional basis. Figure 5-4 depicts typical monthly
precipitation by state.
•Connecticut
• Maine
Massachusetts
•NewHampshire
•Rhode Island
Vermont
New Jersey
New York
Month
Figure 5-4
Average monthly precipitation (1971-2000) for states in
the Northeast region
5.2.1.3 Water Use by Sector
Figure 5-5 shows freshwater use by sector in the
Northeast.
Domestic self-
supply
2
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Chapter 5 | Regional Variations in Water Reuse
reclaimed water at its power plant on campus. Another
industrial facility in Connecticut uses reclaimed water
where it's feasible to meet a zero-discharge
wastewater permit. Maine has significant potable water
resources and, as illustrated in Figure 5-5, has the
greatest opportunity for water reclamation within the
energy and industrial sector. Because the
manufacturing of paper and wood products demands
large amounts of water, it is likely that water reuse
projects will develop in these sectors as potable water
resources are seasonally and locally stressed.
The energy sector in Massachusetts has already
provided water reclamation opportunities at power
plants like Dominion Power's Brayton Point Power
Plant in Somerset, Mass. Industrial wastewater
reclamation is also a growing market sector. An
excellent example of industrial wastewater reclamation
is the EMC Headquarters in Hopkinton [US-MA-
Hopkinton]. 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 case-
by-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 set-
back distances for these four categories of reuse.
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Chapter 5 Regional Variations in Water Reuse
Vermont
Vermont has adopted rules for indirect discharge that
require that land-based discharge (including forested
spray fields) be considered prior to approval of surface
water discharge.
New York
There are no formal guidelines or regulations in New
York, and initial work on guidelines was suspended
due to budget constraints. In highly developed areas
such as Manhattan, the cost to extend dual piping
systems from central wastewater reclamation facilities
is cost prohibitive. There are isolated uses of
reclaimed water in the state for cooling purposes with
supply and quality parameters agreed to in site
specific contracts. The 2004 guidelines (Chapter 5.7.7)
recounts development of an intergovernmental
agreement between the Oneida Indian Nation and the
city of Oneida. The city's reclaimed water was supplied
to the Indian Nation to enable development of a casino
and golf complex by allowing the irrigation demands of
the complex to be met without stressing water
resources.
New Jersey
In January 2005, the New Jersey Department of
Environmental Protection issued a draft "Technical
Manual for Reclaimed Water for Beneficial Reuse,"
and proposed regulation in 2008. These regulations
were codified on January 5, 2009 as New Jersey
Administrative Code 7:14A-2.15. Section 2.15
establishes application requirements for Reclaimed
Water for Beneficial Reuse (RWBR) and states that
any feasibility studies conducted shall be performed in
accordance with the Technical Manual. The
regulations define two main categories of RWBR—
public access and restricted access. The Technical
Manual provides detailed information to applicants on
the procedure for developing and implementing an
RWBR program.
Connecticut and Maine
There are no formal regulations regarding water reuse
in Connecticut or Maine. Installations are approved on
a case-by-case basis.
USVI
Currently, there are no water reuse regulations
promulgated by the USVI. Water reuse for irrigation is
limited to small, on-site installations and no large scale
or public projects have been undertaken. Discharges
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-by-
case 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-ME-
Snow). In Vermont, one ski area, one highway rest
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Chapter 5 | Regional Variations in 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 [US-
MA-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-MA-
Gillette 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.
Mid-Atlantic Region
lUS
Population Land Use
Figure 5-6
Change in population (2000-2010) and developed
land (1997-2007) in the Mid-Atlantic region,
compared to the United States
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Chapter 5 Regional Variations in Water Reuse
5.2.2.2 Precipitation and Climate
The climate in the Mid-Atlantic region is largely
classified as humid subtropical. Spring and fall are
warm, while winter is cool with annual snowfall
averaging 14.6 in (37 cm). Winter temperatures
average around 38 degrees F (3.3 degrees C) from
mid-December to mid-February. Summers are hot and
humid with a July daily average of 79.2 degrees F
(26.2 degrees C). The combination of heat and
humidity in the summer brings very frequent
thunderstorms and, therefore, abundant precipitation
during the warmest months. Figure 5-7 depicts
average monthly precipitation in the Mid-Atlantic
region by state.
-Delaware
-Washington, DC
-Maryland
-Pennsylvania
Virginia
-West Virginia
0.0
S 5 <
Month
Figure 5-7
Average monthly precipitation in the Mid-Atlantic
region
5.2.2.3 Water Use by Sector
Figure 5-8 shows freshwater use by sector in the Mid-
Atlantic Region.
Public supply
8%
Domestic self-
supply
|rrigation
Livestock
Aquaculture
2%
Industrial
7%
Mining
Figure 5-8
Freshwater use by sector for the Mid-Atlantic 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
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Chapter 5 | Regional Variations in Water Reuse
govern the centralized reclamation of domestic,
municipal, or industrial wastewater and subsequent
reuse, other Virginia state agencies have regulations
or guidelines that affect water reuse, determined in
most cases by the type of wastewater to be reclaimed.
The Virginia Department of Health has regulations that
allow the on-site treatment and reuse of reclaimed
water in conjunction with a permitted on-site system
for toilet flushing, and provides guidelines for the use
of harvested rainwater and graywater. The Virginia
Department of Housing and Community Development
has regulations for the indoor treatment and plumbing
of graywater and harvested rainwater, and for the
indoor plumbing of reclaimed water meeting
appropriate regulatory standards administered by the
DEQ for indoor uses. The Virginia Department of
Conservation and Recreation has limited regulations
for the use of stormwater and evaluates such
proposals on a case-by-case basis. A discussion of
the development of the Virginia water reuse
regulations is provided in a case study [US-VA-
Regulations].
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.
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Chapter 5 Regional Variations in Water Reuse
• The Maple Avenue WWTP in Halifax County is
permitted to produce 1.0 mgd (43 L/s) of Level 2
reclaimed water. Most of this water will be
delivered to a wood-burning power producer for
cooling and boiler feed.
Other projects that have been grandfathered until they
expand their reclaimed water production or distribution
capacity include the Proctors Creek Wastewater
Treatment Facility (WWTF) and the Remington WWTF
in Chesterfield and Fauquier Counties, respectively.
Both facilities provide treated effluent of quality better
than or equal to Level 2 reclaimed water to coal-
burning 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 [US-
DC-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 [US-
PA-Kutztown]. Although interior residential reuse
would not be permitted under current guidelines,
Hundredfold Farm in Adams County was the first rural
cohousing community in Pennsylvania and uses their
treated wastewater for toilet flushing as well as
irrigation. There are also 11 industrial establishments
and 14 municipal treatment plants that use their
treated wastewater for irrigation purposes.
Maryland
Maryland has 35 spray irrigation systems using
reclaimed water, with the largest being 0.75 mgd (32
L/s). The majority of the systems are for agricultural
irrigation. Nine of the spray irrigation systems are for
golf course irrigation. Other reuse systems included
four rapid infiltration systems, two overland flow, and
three drip irrigation systems (Tien, 2010).
5.2.3 Southeast: Alabama, Florida,
Georgia, Kentucky, Mississippi, North
Carolina, South Carolina, and Tennessee
This section focuses on the regulatory context and
drivers for water reuse in eight states in the Southeast.
5.2.3.1 Population and Land Use
The Southeast is one of the most populous and fastest
growing regions in the United States. With nearly 19
million people, Florida is the most populous of the
southeastern states. It is followed by Georgia and
North Carolina, each with approximately 10 million
residents, and then Tennessee with over 6 million
people. Historically, the Southeast states have relied
heavily on agriculture. However, in the last few
decades, the region has become more urban and
industrialized. Despite this development, some
southeastern states still have not implemented
sophisticated reuse programs. Florida, however, has
one of the largest reuse programs in the country. A
factor that has contributed greatly to the significant
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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.
deep well disposal. Figure 5-10 depicts typical
monthly precipitation in the Southeast by state.
Southeast Region
5.7 .US
0.0
Population Land Use
Figure 5-9
Change in population (2000-2010) and developed land
(1997-2007) in the Southeast region, compared to the
United States
Florida experienced huge growth in population from
1980 to 2010 (93 percent increase), and with that
came a dramatic increase in developed land at nearly
100 percent over what it was in 1982. Georgia, North
Carolina, South Carolina, and Tennessee likewise saw
population growth exceeding the national average. In
these states, population growth likewise corresponded
to an increase in developed land exceeding the
national rate. Because of this stress from growth and
development, Florida and some of the other
southeastern states, particularly in the large urban
centers, present huge opportunities for reuse.
5.2.3.2 Precipitation and Climate
The predominate climate in the Southeast is humid
subtropical with a small area of wet/dry-season tropical
zone in South Florida. Compared to the rest of the
country, states in the Southeast get the most average
rainfall, with close to or above 50 in (127 cm) per year.
Yet, it may be surprising that Florida has probably the
most reuse flow going to landscape irrigation at 360
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
-Alabama
-Florida
Georgia
•Kentucky
-Mississippi
North Carolina
South Carolina
Tennessee
Month
Figure 5-10
Average monthly precipitation in the Southeast region
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 back-
up disposal option such as deep well injection or
surface water discharge.
5.2.3.3 Water Use by Sector
The opportunities for water reuse differ somewhat
among the Southeast states. All of the states have
large opportunities for water reuse in the energy
sector. In Florida and Mississippi, irrigation demand
also provides a large opportunity for reuse.
Figure 5-11 shows freshwater use by sector in the
Southeast.
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Chapter 5 Regional Variations in Water Reuse
Domestic self-
supply
1%
Livestock
1%
Aquaculture
2%
\_lndustrial
5%
Mining
1%
Figure 5-11
Freshwater use by sector for the Southeast region
While irrigation does not seem to present a huge
opportunity for reuse in Alabama, South Carolina, and
Tennessee, the use of reclaimed water for irrigation in
certain circumstances (e.g., where irrigated hayfields
or golf courses are located next to a domestic WWTF)
in these states should not be overlooked. Likewise, in
Florida and Mississippi, where the use of freshwater in
the energy sector is largely overshadowed by reuse for
irrigation, the use of reclaimed water in cooling towers
and other uses at thermoelectric power plants can be
a huge local opportunity for reuse in areas where
those plants are located. In Florida, power plants can
be a reuse utility's largest bulk customer.
In many parts of Florida, reclaimed water is an integral
part of the water supply portfolio, and this trend is
expected to continue. With limited freshwater in many
areas, reclaimed water has allowed communities to
grow and has reduced the need for development of
other alternatives. Irrigation demands in Florida are
second only to Arkansas. This may partly explain why
Florida's most popular use of reclaimed water (68
percent of the total reuse flow) is irrigation (public
access areas, 58 percent, and agricultural irrigation 10
percent) (FDEP, 2012a). Farming is the largest
industry in Florida, and the use of surface water and
groundwater sources for irrigation remain significant
withdrawals of the freshwater supply in the state.
There are two main impeding factors to expanding the
use of reclaimed water for agricultural activities:
negative perception of reclaimed water by farmers and
their customers, and the rural nature of farmland,
which means that there are high financial and energy
costs to supply reclaimed water to these areas. The
public use of water is also huge and indicates a big
opportunity for aquifer recharge and potable reuse;
however, this represents the most stringent level of
treatment and most potential for public resistance.
Florida is not a center of heavy industry, and as a
result, industry is the smallest of the water uses in
Florida. Leading industries include food processing,
electric and electronic equipment, transportation
equipment, and chemicals. While the industrial and
energy sectors are not huge parts of the total water
use in Florida, the opportunities presented by these
industries, particularly in the towns where large
industrial facilities and power plants are located, are
desirable to reclaimed water providers. Alabama,
Georgia, Mississippi, South Carolina, and Tennessee
all have higher industrial water use demands that are
in the range of 5 to10 percent.
Potable Water Availability and Rates
With the exception of Florida, Arkansas, and
Mississippi, the majority of freshwater withdrawn in the
Southeast comes from surface water sources. In
Florida, nearly 90 percent of the potable water is
supplied by groundwater. Potable water rates are still
relatively cheap due to the low cost of production (very
little treatment required). However, in some parts of
the state, particularly in the Tampa Bay area and
Southeast parts of the state and along the coastline in
the Northeast and parts of the Panhandle, the aquifers
are stressed. In these stressed areas, called Water
Resource Caution Areas by state statutes, potable
water rates may be higher and may be a better
reflection of the real cost of providing water. Within
these Water Resource Caution areas, investigating the
feasibility of reuse programs is mandated, and utilities
(water supply and wastewater management) as well
as water users must implement reuse to the extent
that is determined to be feasible.
Potable water rates in several municipalities surveyed
in Florida in 2003 ranged from a low of $0.50/1,000
gallons ($0.13/1000 L) to a high of more than
$10.00/1,000 gallons ($2.64/1000 L), depending on
the gallon usage (tiered rate); however, for most
residential uses the average potable water rate was
around $1.50/1,000 gallons ($0.40/1,000 L)
(Whitcomb, 2005). (See also Table 7-1 for sample
rates.) Note that as utilities in Florida adopt
conservation rate structures, potable water rates have
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increased above these 2003 values. Reclaimed water
rates in the same year in Florida were very
competitive, ranging from $0.19 to $5.42/1,000 gallons
($0.05 to $1.43/1,000 L) for residential customers and
from $0.05 to $18.30/1,000 gallons ($0.01 to
$4.83/1,000 L) for non-residential customers (FDEP,
2012a). Except for a few isolated instances, water in
the southeastern states is generally undervalued,
therefore inhibiting the perceived need for water reuse.
5.2.3.4. States' Regulatory Context
Alabama, Georgia, Kentucky, Mississippi, South
Carolina, and Tennessee
Alabama and Georgia each have guidelines governing
various aspects of reuse. Kentucky does not have
regulations or guidelines governing reuse. Mississippi
has regulations that cover the potential for reclaimed
water to be reused for restricted urban reuse,
agricultural reuse for non-food crops, and industrial
reuse. South Carolina has regulations governing reuse
that stipulate that wastewater facilities that apply to
discharge to surface waters must conduct an
alternatives analysis to demonstrate that water reuse
is not economically or technologically reasonable.
Tennessee allows reclaimed water to be distributed for
land application reuse by industrial customers,
commercial developments, golf courses, recreational
areas, residential developments, and other nonpotable
uses. Implementation of reuse programs are through
the NPDES or state operating permit programs with
additional requirements for reuse that are specified in
the permits. Tennessee guidelines for reuse include
the Design Guidelines for Wastewater Treatment
Systems Using Spray Irrigation.
Florida
Florida has one of the more mature water reuse
programs that continues to evolve with new
environmental and regulatory drivers. Florida leads the
United States with 49 percent of treated wastewater
reclaimed and reused (FDEP, 2012a). The reuse
capacity in the state is higher—up to 64 percent of the
state's permitted domestic wastewater capacity is
dedicated to reuse. In 2006, FDEP's Water Reuse
Program was the first recipient of the EPA Water
Efficiency Leader Award. However, Florida realizes
only a fraction of reuse opportunities. In 2011, a total
of 57 large domestic wastewater treatment facilities did
not provide reuse of any kind. This unused capacity
presents a potential to expand the availability of
reclaimed water in the state. The 2008 Legislature
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
180mgd (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.
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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 LI 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).
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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-GA-
Clayton 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 USAGE 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 LI 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.
Agriculture
Irrigation
10%
Groundwater
Recharge
11%
Wetlands and
Other
5%
Figure 5-12
Water reuse in Florida by type (FDEP, 2012)
Figure 5-13 depicts the large population centers in
Florida where reuse has the largest opportunity for
growth. The statewide per capita usage based on
2011 population estimates and total reclaimed water
utilization in 2011 was 38 gpd (143.8 L/day) of reuse
per person in Florida. The Orlando-Tampa
metropolitan area averages well over 50 gpd (189
L/day) per person, while Miami-Dade and Jacksonville
Metropolitan areas average 7 and 10 gpd (26.5 and
37.9 L/day) per person, respectively (FDEP, 2011).
A future water quality issue that numerous stakeholder
groups, including water resources utilities, have been
watching in the state of Florida is the development of
Numeric Nutrient Criteria (NNC). The national NNC
dialogue began in 1998 with EPA's National Nutrient
Strategy that detailed the approach EPA envisioned "in
developing nutrient information and working with
states and tribes to adopt nutrient criteria as part of
their water quality standards." (EPA, 2007)
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Per Capita Reuse Flow 2011
State Average = 38.19 gpd/person
Over 50 gpd/person
Between 15 and 50 gpd/person
Below 15 gpd/person
Top 10 most populous counties
Note: Calculations of reuse flow per capita includes population
that is served by onsite sewage treatment and disposal
systems (e.g., septic systems).
Figure 5-13
Map of per capita reuse flow by county in Florida
(FDEP, 2012)
Working in partnership with EPA, FDEP established a
Technical Advisory Committee in January 2003 and
began development of state criteria. In 2008, a federal
legal and rulemaking process ensued, which led to
EPA developing their own freshwater NNC in 2010
and working towards proposing rules for primarily
marine waters in 2012. Additionally in 2012, the FDEP
NNC passed through the state rulemaking and legal
process, and that rule has been submitted to EPA for
review. It is still uncertain whether the federal or state
led NNC rulemaking process will eventually evolve into
the NNC rule that will be implemented in the state of
Florida. Interested parties should stay tuned to both
the federal and state processes to track important
milestones over the coming year (EPA, n.d.; FDEP,
2012b; FR 77, 2012:13496-13499).
Unrelated to NNC, the 2008 legislature enacted laws
that prohibit ocean discharge of treated wastewater by
2025 except as a backup to a reuse system. Sixty
percent of the water currently discharged in ocean
outfalls will have to be reused for a beneficial purpose,
increasing reclaimed water use by at least 180 mgd
(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
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advanced wastewater treatment to meet limit of
technology nutrient removal are much like events in
1972 that led to the creation of the dual-piped
reclaimed water system for St. Petersburg, Fla. The
Wilson-Grizzle Act was passed by the Florida
legislature in 1972. It required all utilities to cease
discharge into Tampa Bay unless they installed
advanced wastewater treatment equipment to meet
nutrient reduction requirements. Today, St. Petersburg
is known as the largest residential reclaimed water
service provider in the United States (Crook, 2005).
This same opportunity to develop dual piped water
systems for new developments could increase use of
reclaimed water for residential irrigation over time,
minimize increased demands on the potable water
system, and delay or eliminate costly nutrient removal
improvements at WWTPs.
Going green (or, in some cases, gray) is sometimes
driven by new development decisions to create a
LEED-certified development or building. In the
certification process, up to 10 points can be obtained
through use of reclaimed water or on-site use of
alternate waters. Currently in North Carolina, the use
of graywater without treatment is not allowed (15A
NCAC 18A); however, 2011 Session law has called for
the development of graywater reuse rules to facilitate
its safe and beneficial use. Currently, state/local
plumbing authorities allow for the use of graywater for
toilet flushing. Both national plumbing codes (Uniform
Plumbing Code and International Plumbing Code)
require use of purple pipe for all alternate water on-
site. 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 Gary has one of the more established
reclaimed water systems in North Carolina, starting in
2001 with 9 mi of distribution pipeline from the North
Gary WRF serving 350 customers (Miles, et al., 2003;
The Town of Gary, n.d.; and [US-NC-Cary]). The town
also provided a central bulk fill station at the North
Gary 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 Gary reclaimed water as
"Purple...the new Gold" by serving as a resource
during the drought to maintain landscape (Westmiller,
2010).
Figure 5-14
Gary, N.C., bulk fill station allows approved
contractors, landscapers, and town staff to use
reclaimed water
Durham County, N.C., expanded its reclaimed water
program with storage, plant improvements, and a new
distribution and metering system to supply
supplemental reclaimed water to the town of Gary to
begin service to the Gary 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
Gary and other county demands, and a town of Gary
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
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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 Us). 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 I PR
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,
III. and its suburbs form the largest metropolitan area
in the Midwest, followed by Detroit, Mich.; the Twin
Cities (Minneapolis and St. Paul, Minn.); Cleveland,
Ohio; St. Louis, Mo. and the Kansas City, Mo. area.
Figure 5-15 shows change in population in the
Midwest in the past decade, relative to the United
States. The figure also shows the percent change in
developed land coverage from 1997-2007.
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Chapter 5 | Regional Variations in Water Reuse
• Midwestand Great Lakes
Regions
• US
0.0
Population Land Use
Figure 5-15
Change in population (2000-2010) and developed land
(1997-2007) in the Midwest and Great Lakes region,
compared to the United States
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.
Month
Figure 5-16
Average monthly precipitation in the Midwest
5.2.4.3 Water Use by Sector
Figure 5-17 shows freshwater use by sector in the
Midwest and Great Lakes Region.
Domestic self-
supply
1%
Livestock
1%
Aquaculture
1%
\_lndustrial
5%
Mining
2%
Figure 5-17
Freshwater use by sector for the Midwest and Great
Lakes region
Given the different climatic regions and types of
industry in the Midwest, water use varies among
states. One common use for states with larger river
sources such as the Mississippi, Missouri, and Ohio
Rivers is the non-consumptive use for once-through
cooling water at power generation facilities. This water
use is not the optimum candidate for reclaimed water
since it does not replace a consumed supply of
groundwater or surface water, as would be the case
for power plants with recirculated cooling systems.
Lower effluent limit requirements being set for some
municipal dischargers is expected to result in more
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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 once-
through cooling, as depicted in Figure 5-18. Power
generation facilities are supplied mostly by surface
waters.
700
Industrial
12%
Public Potable
WaterSupply
16%
Irrigation
10%
Figure 5-18
Water use in Minnesota, 2007 (Source: MDNR 2008)
The next largest use of water, around 16 percent of
the total, is for potable water supply (water utilities),
distributed by municipalities for domestic, commercial
and industrial uses. Nearly two-thirds of the potable
water in Minnesota is supplied by groundwater, as
shown in Figure 5-19.
• Surface
• Ground
Public Industrial
potable water
supply
Irrigation
Other
Figure 5-19
Water use in Minnesota by source*, 2007 (Source:
MDNR 2008)
Water withdrawn by industries (those not served by
water utilities) for various processing needs accounts
for about 12 percent of the total water used in
Minnesota. The majority of this is surface water used
by the pulp and paper and mining industries.
Agricultural processing accounts for the largest use of
groundwater by industry. Irrigation accounts for about
9 percent of the total water used, and all other water
uses comprise about 4 percent of the total water use.
Like many Midwest states, the larger users of
groundwater in Minnesota are not always in proximity
to populated areas with a sufficient reclaimed water
supply, notably for agricultural irrigation and
processing facilities. In 2005, the total industrial water
use in Minnesota, excluding surface water supplies for
power facilities, was estimated to be 445 mgd (19.5
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.
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5.2.4.5 Context and Drivers of Water Reuse
This section identifies drivers and characteristics that
broadly apply to Midwest states with examples of
current reuse practices and develops a range of
considerations using Minnesota as an example. There
are a variety of opportunities for broader
implementation of water reuse practices in the
Midwest. There are also a host of factors that affect
the feasibility of reuse implementation. Water reuse
practices in the Midwest are site-specific and based on
a variety of drivers. The drivers can be grouped into
four categories: water quality, water quantity,
sustainable economic growth, and environmental
stewardship (MCES, 2007).
Water Quality
A safe, cost-effective, and adequate water supply
generally has been readily attained for most Midwest
communities and industries. Historic water reuse
applications have been water quality driven.
Agricultural irrigation using treated wastewater effluent
has been practiced in the Midwest's rural areas in lieu
of summer pond discharges for facilities a significant
distance from an acceptable receiving stream. More
recent water reuse applications driven by discharge
limitations include golf course irrigation in urban and
resort areas and toilet flush water for buildings.
Water quality issues will drive future water reuse in the
Midwest. As growing communities generate additional
wastewater, there will be a need to provide higher
levels of wastewater treatment to maintain or decrease
discharge loads to the region's waterways. The
development of TMDLs in the Mississippi River basin's
sub watersheds will result in reduced effluent limits for
phosphorus, solids, and total nitrogen for many
municipal dischargers. Water reuse may become a
cost-effective practice for communities where
advanced treatment processes are required to meet
new receiving stream discharge limits. If these
communities are experiencing or forecasting water
supply limitations, the benefits of a water reuse option
could be even more pronounced. A new advanced
WWTF in East Bethel, Minn, in the Twin Cities metro
area will discharge high quality reclaimed water to
rapid infiltration basins rather than discharging to the
river.
Water Quantity
While water quality discharge limitations will
increasingly be a factor in the Midwest, it is anticipated
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.
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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.
Figure 5-20
The SMSC WRF and wetlands
Reclaimed water from Columbia, Mo., is directed to a
series of managed wetlands operated by the Missouri
Department of Conservation. The wastewater is fed
through a series of channels and gates, largely by
gravity, offsetting water that would have to be pumped
from the ground or the nearby Missouri River for the
wetlands. This saves on electrical costs, allowing the
scarce public money to be spent instead on habitat
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, III., a small rural community
west of Chicago, recently developed an ordinance to
promote the preservation of rapidly shrinking
groundwater supplies when other sources of water
exist for specific uses. The ordinance describes
specific instances where municipal water supply users
would be required to use reclaimed water. The
ordinance encourages water reuse in general. For
example, industries are encouraged to use reclaimed
water for nonpotable industrial processes. There are
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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.
Figure 5-21
Mankato Water Reclamation Facility
Water supply scarcity in Minnesota's southwest region
affected the siting of ethanol facilities during the biofuel
industry expansion of the mid-2000s. In conjunction
with other planning activities, state agencies increased
inventory research on groundwater resources and
streamlined permitting practices. In addition, the state
legislature became involved by supporting initiatives
for water reuse, emphasizing the economic
sustainability goals tied to water (MPCA, 201 Oa).
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 201 Ob).
Long-term planning for water reuse in Minnesota and
other Midwest communities will be influenced by the
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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 (M PC A 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.
South Central Region
lUS
Population
Land Use
Figure 5-22
Change in population (2000-2010) and developed
land (1997-2007) in the South Central region,
compared to the United States
Compared to other regions, the South Central region is
second only to the Mountain and Plains region in
percent population growth. In the Southwest, the
greatest population growth over the past decade has
occurred in Texas (20.9 percent) and New Mexico
(13.2 percent).
5.2.5.2 Precipitation and Climate
Figure 5-23 depicts average monthly precipitation in
the South Central region by state.
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Chapter 5 | Regional Variations in Water Reuse
•Arkansas
• Louisiana
•New Mexico
•Oklahoma
•Texas
Month
Figure 5-23
Average monthly precipitation in the South Central
region
The graphs above present long-term average
precipitation. Drought conditions for the last three
years in the region have depleted surface water
reservoirs and reduced recharge to groundwater
aquifers. According to the U.S. Drought Monitor, as of
May 1, 2012, over 83 percent of Texas was still in
severe (D-3) to exceptional (D-5) drought conditions
(Rosencrans, 2012). Southeastern New Mexico shares
the fate of West Texas with severe to exceptional
drought over most of the state, with relieve to
abnormally dry (D-0) conditions in the northwest
corner of New Mexico.
With reservoir and aquifer levels dropping, many
communities are increasing their conversion to or use
of reclaimed water. In West Texas, the Colorado River
Municipal Water District is constructing a 2.3 mgd (101
L/s) IPR project that will convert Big Spring wastewater
into higher than potable quality and blend the product
water with raw water from one of three reservoirs that
still has some water. The blended water is then treated
at surface water treatment plants in six different
communities [US-TX-Big Spring]. The community of
Brownwood is in design/construction of a direct
potable augmentation plant to supplement supply from
a reservoir that may be depleted by the end of 2012
without significant rainfall.
5.2.5.3 Water Use by Sector
Figure 5-24 shows freshwater use by sector in the
South Central region.
Mining _
3%
Industrial.
8%
Aquaculture _/*
1%
Livestock
3%
Domestic self-
supply
1%
Figure 5-24
Freshwater use by sector for the South Central region
Irrigation is the largest water user in the region, and
reclaimed water is commonly used for irrigation.
However, the cost of incremental treatment and
distribution for irrigation is a barrier to significant
expansion in this sector. Thermoelectric power
generation is another large potential use sector for
expanding reuse.
5.2.5.4. States' Regulatory Context
Arkansas and Louisiana
At this time, Louisiana does not have regulations or
guidelines specifically addressing water reuse.
Arkansas had guidelines prior and now has adopted
land disposal regulations with a provision for irrigation
of forage and non-contact crops.
New Mexico
In 2007, New Mexico Environment Department
(NMED) created an updated reclaimed water guidance
document "NMED Ground Water Quality Bureau
Guidance: Above Ground Use of Reclaimed Domestic
Wastewater" that supersedes 1985 and 2003 policy
statements. Current guidance identifies four different
qualities of reclaimed water, with Class 1A being the
highest quality for unrestricted urban uses. Class 1A is
based on treatment processes that remove colloidal
material and color that can interfere with disinfection.
Classes 1B, 2, and 3 are based on secondary
treatment processes. Spray irrigation of food crops is
not allowed, although surface irrigation with Class 1B
or 1A is allowed without contact with edible portions of
crops.
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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
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Chapter 5 | Regional Variations in Water Reuse
nonpotable uses as well as for stream and aquifer
augmentation.
Texas
El Paso Water Utility (EPWU) began pilot testing for
IPR to augment the Hueco Bolson aquifer in 1978 with
operation of an 8 mgd (351 L/s) facility beginning in
1985. They have expanded their portfolio of water
reuse by conventional distribution of reclaimed water
for irrigation, doubling the aquifer augmentation
system and implementation of the largest inland
brackish desalination project in the United States with
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) [US-
TX-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
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Chapter 5 Regional Variations in Water Reuse
pathogen regrowth by maintaining a minimum chlorine
residual level.
Careful consideration of soil composition and existing
plant material in selection of potential irrigation
customers and impacts of aggressive conservation
programs are all aspects of balancing water that have
reshaped the planning and phasing of reuse programs
in the United States.
In-depth evaluation of soils subjected to irrigation with
reclaimed water has been one of the most important
considerations in planning a reuse program in El Paso.
These studies have been instrumental in the effective
use of reclaimed water and prevention of further soil
degradation. Costs for biennial soil monitoring have
also been budgeted by the utility, with no cost
assessed to the customer. Customers do absorb the
cost for any plant loss and soil amendments
necessary.
Conservation Impact on RW Quality
Other conservation measures, such as use of low and
ultra-low flow showerheads, toilets, sinks, washers,
etc., continue to increase throughout the United
States, so wastewater flows to the treatment facilities
may be decreasing. Added to this is the increased use
of in-situ graywater systems and increased tendencies
for achieving sustainability for "green buildings" energy
and conservation credits, where applicable. All
combined, these factors may, in some instances,
impact not only the quantity but also the quality of
wastewater available for reclamation.
A study performed by EPWU in 2007 reflected the fact
that increased conservation measures contributed to a
decline of flows into WWTPs (Figures 5-25 and 5-26).
In a period from 1994 to 2006, the strength of the
wastewater inflow increased in terms of BOD5 (Figure
5-27) and ammonia nitrogen (NH3-N) (Figure 5-28) at
three of the WWTPs studied. Total suspended solids
(TSS) concentration also increased at one of the
WWTPs (Figure 5-29) (Ornelas and Rojas, 2007).
Impacts from water conservation must also be
considered during a reuse project planning phase,
including reductions in flow where no population
increases are expected to overcome decreases in
flow. Similar impacts to reduced wastewater influent
flows and higher strength wastewater influents have
been found in San Antonio and San Diego.
Oklahoma
Reclaimed water has been used in some portions of
Oklahoma (Oklahoma University golf course, Norman,
Okla.) since 1996. More recently, the city of Norman
conducted public forums on Sustainable Water
Resources in 2010 and included water reuse as one of
the available options to conserve and extend the
regional water resources (Clinton, 2010).
On May 9, 2011, the Bureau of Reclamation (USBR)
announced the selection of nine feasibility studies for
funding under WaterSMART's Title XVI Water
Reclamation and Reuse Program in California,
Oklahoma, and Texas. The Central Oklahoma Water
Conservancy District will conduct a feasibility study in
collaboration with surrounding entities to assess
alternatives to augment the supply of Lake
Thunderbird in Central Oklahoma through the
treatment of effluent or surface water. The study will
assess alternatives to help postpone or eliminate
withdrawals from the local aquifer and alleviate
pressure to secure inter-basin water transfers (WRA
News, 2011).
Title XVI of P.L. 102-575 provides authority for the
USBR water reuse program. WaterSMART is a
program of the U.S. Department of the Interior that
focuses on improving water conservation and
sustainability (USBR, 2012).
New Mexico
New Mexico also is beginning to use more reclaimed
water to augment limited natural resources. Projects
are in place in many communities (Las Cruces,
Alamogordo, Hobbs, Gallup, Santa Fe, and Clovis),
and larger projects are expanding in Albuquerque and
the surrounding area. The Albuquerque Bernalillo
County Water Utility Authority operates the Southeast
Water Reclamation plant, which provides reclaimed
water to several golf courses, city parks, and a power
plant under a simplified regulatory framework.
Irrigation of park green space replaces 12 percent of
the city's water demand (Stomp, 2004). Including
reclaimed water to reduce aquifer withdrawals is
critical to slowing aquifer decline and subsidence in
Albuquerque.
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Chapter 5 | Regional Variations in Water Reuse
130
ISO
170
160
ttt
140
130 •
120
PER CAPITA WATER CONSUMPTION
ALL EPWU CUSTOMERS
,Y»:*-£:•£•-. a:-:-
C-:-*-:t *-: -.r.t
r!-.::.-;
il't iV*:*'nJ!i -:-*J5t
(joal tor 2U1U - 140 gpcd
2d06-136flpcd
Figure 5-25
Water consumption in El Paso, Texas
WASTEWATER FLOWS
MAXIMUM. MINIMUM. AND AVERAGE
£ S S
-MAX-«-MIN
AVG
Figure 5-26
Wastewater flows in El Paso, Texas
Wastewater Influent Strength
Biochemical Oxygen Demand (BODS)
Annual Averages
^ jtn •
- /bo
m
Q
o 200 -
CD
I150'
m
3
? cn .
< a
J>
S^
^^^
r~-~~~ "*^
1994 1997 2000 2003 2006
YEAR
-»-NW
HS
RB
Plant Name
Wastev/ater Influent Strength
Ammonia Nitrogen (NH3-N)
Annual Averages
I
f«
|,S
1 5
^ — *
• ••-
WW 1997 2000 Z003 2006
YEAR
Plant Name
-•-NW
HS
RB
Figure 5-27
Wastewater influent strength, BOD5
Figure 5-28
Wastewater influent strength, NH3-N
Wastewater Influent Strength
Total Suspended Solids (TSS)
Annual Averages
1
% 100 -
•
^ "* — ,^-*^
~ , — « ^
1994 1997 2000 2003 2006
Plant Name
HS
RB
YEAR
Figure 5-29
Wastewater influent strength, TSS
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2012 Guidelines for Water Reuse
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Chapter 5 Regional Variations in Water Reuse
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.
Mountain and Plains
Region
lUS
Population Land Use
Figure 5-30
Change in population (2000-2010) and developed land
(1997-2007) in the Mountain and Plains region,
compared to the United States
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.
•Colorado
• Montana
• North Dakota
•South Dakota
-Utah
Wyoming
0.0
Month
Figure 5-31
Average monthly precipitation in the Mountain and
Plains region
Rainfall in this region typically peaks during the
summer growing months. Combined with low density
development (on average), this weakens some
demand for reclaimed water use. As noted previously
for Colorado, due to water rights conflicts, rainfall
capture is not allowed to supplement local water
demands.
5.2.6.3 Water Use by Sector
Figure 5-32 shows freshwater use by sector in the
Mountain and Plains region.
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Chapter 5 | Regional Variations in Water Reuse
Thermoelectric
15%
Industrial
Public supply
8% Domestic self-
supply
Aquaculture
2%
Livestock
2%
Figure 5-32
Freshwater use by sector for the Mountain and Plains
region
Although irrigation is the largest water user in the
region and reclaimed water is commonly used for
irrigation, cost of incremental treatment and
distribution to is an impediment to expansion of
reclaimed water integration.
5.2.6.4. States' Regulatory Context
Colorado
The Colorado Water Quality Control commission
administers four reclaimed water regulations in the
Code of Colorado Regulations 1002-84 Reclaimed
Water Control Regulations. The regulation identifies
three qualities of reclaimed water: Classes 1, 2, and 3,
with Class 3 being the highest quality. Class 3 requires
secondary treatment filtration and disinfection for use
in unrestricted urban applications. Colorado water
rights limit the amount of reclaimed water that can be
used, with quantities limited to water quantities
imported from western Colorado to the east side of the
Rocky Mountains [US-CO-Water Rights].
Montana
Montana established graywater rules in 2007 and
updated those rules in 2009 as one step in providing
higher quality on-site treatment and reducing water
demands. Over the last three years, Montana DEQ
staffs have been developing new wastewater design
and treatment regulations, including a guidance
document on reclaimed water. As of the time of
publication, the new rules and standards are currently
under review and public hearings.
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.
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Chapter 5 Regional Variations in Water Reuse
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, US-
CO-Denver Zoo, US-CO-Denver Energy, and US-CO-
Sand 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.
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Chapter 5 | Regional Variations in Water Reuse
14.0
12.0
Pacific Southwest Region
lUS
Population
Land Use
Figure 5-33
Change in population (2000-2010) and developed land
(1997-2007) in the Pacific Southwest region, compared
to the United States
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.
• Arizona
•California
•Hawaii
•Nevada
Month
Figure 5-34
Average monthly precipitation in the Pacific Southwest
region
There is obvious variance in annual rainfall between
Hawaii and the three contiguous states. Within
California, the average condition shown in the graph is
potentially misleading, with an annual average low
rainfall of 1.6 in (4 cm) at Cow Creek in Death Valley
and 104.18 in (264.6 cm) at Honeydew in northern
California. With a statewide average of 22.2 in (56.3
cm), California ranks 40 in the list of wettest states
(Coolweather, n.d.). Arizona averages 13.61 in (34.6
cm) per year with an annual range from 3.01 in (7.6
cm) in Yuma to 22.91 in (58.2 cm) in Flagstaff. Arizona
is ranked the 47th wettest state (Coolweather, n.d.).
Nevada is the driest state in the United States. Annual
rainfall varies from 4.49 in (11.4 cm) per year in Las
Vegas to 9.97 in (25.4 cm) in Ely (NOAA, n.d.). With
the largest population and driest climate in the state,
Las Vegas faces a significant challenge in meeting its
water resource needs.
Hawaii's extreme geographical variations are manifest
in extreme geographical rainfall variations. Although
almost half the state is within 5 mi (8 km) of the
seashore, 50 percent of the state is above 2,000 ft
(609.6 m) in elevation and 10 percent is above 7,000 ft
(2,133.6 m). Three mountain masses rise over 10,000
ft (3,048) above mean sea level, with Mauna Loa and
Mauna Kea rising over 13,000 ft (3,962.4 m).
It is not unusual for snow to cap the summits of Mauna
Loa, Mauna Kea, and Haleakala when winter storm
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Chapter 5 Regional Variations in Water Reuse
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.
Domestic self-
supply
1%
Figure 5-35
Freshwater use by sector for the Pacific Southwest
region
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-by-
case basis by the ADEQ.
In August 2009, the Governor formed a Blue Ribbon
Panel on Water Sustainability consisting of 40
panelists representing a cross-section of state interest
[US-AZ-Blue Ribbon Panel]. The purpose of the panel
was "To advance statewide sustainability of water by
increasing the reuse, recycling and conservation of
water to support continued economic development in
the state of Arizona while protecting Arizona's water
supplies and natural environment." To accomplish this,
the panel developed five goals and five working
groups to address: 1) Increasing the volume of
reclaimed water used for beneficial purposes in place
of raw or potable water; 2) Advancing water
conservation; 3) Reducing the amount of energy
needed to produce, deliver, treat, reclaim, and reuse
water; 4) Reducing the amount of water required to
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Chapter 5 | Regional Variations in 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 water-
quality objectives in the basin plans.
The special provisions for groundwater recharge
projects in the Recycled Water Policy require site-
specific, project-by-project review and establish criteria
for RWQCB approval, including a one year, expedited
permit process for projects that use RO treatment for
surface spreading.
CDPH regulations are codified within the California
Code of Regulations, with specific provisions related to
reclaimed water within California Code of Regulations
Title 22 and 17. Regulations governing nonpotable
reuse include specific water quality, treatment, and
monitoring requirements identified in California Code
of Regulations Title 22 and enforced by the various
RWQCBs. These regulations have remained relatively
static over the last 10 years, with recent changes
related primarily to laboratory and operator certification
requirements.
In addition, CDPH has developed a series of draft
groundwater recharge regulations that are used as a
basis for the case-by-case approval of individual
groundwater replenishment projects. Current codified
regulations in California Code of Regulations Title 22
include only narrative requirements for IPR, without
specific provisions for treatment or water quality.
Amendments to the California Water Code (CWC)
made in 2010 require CDPH to adopt formal
groundwater recharge regulations by December 31,
2013, while developing surface water augmentation
regulations and a policy on direct potable reuse by
December 31, 2016 (CWC 13350, 13521, and 13560
to 13569).
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The current draft of the groundwater recharge
regulations was published in November 2011 and
defines separate requirements for direct injection,
surface spreading, and surface spreading without
advanced treatment. Full advanced treatment, defined
as RO followed by advanced oxidation, is required for
direct injection or for surface spreading projects where
strict TOC limits cannot be met and reclaimed water
contribution to the groundwater exceeds 20 percent.
The draft regulations include specific limits for TOC,
total nitrogen, and other regulated and previously
unregulated water quality parameters, as well as
pathogen reduction requirements that include a 12-log
reduction for enteric virus, 10-log for Giardia cyst, and
10-log for Cryptosporidium oocyst. Recharged water
must be retained underground for a minimum of two
months. The regulations also allow for alternative
treatment approaches evaluated on a case-by-case
basis and give credit for soil aquifer treatment when
surface spreading is employed.
Hawaii
All water reuse projects in the state of Hawaii are
subject to the review and approval by the Hawaii State
Department of Health Wastewater Branch. The Hawaii
State Department of Health issued the "Guidelines for
the Treatment and Use of Reclaimed Water" in
November 1993. The guidelines were adopted into
Hawaii Administrative Rules Title 11, Chapter 62,
Wastewater Systems updated in May 2002 and re-
titled, "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-1 B (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
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Chapter 5 | Regional Variations in 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 cross-
connection control and site inspection program [US-
AZ-Tucson].
Other Providers
13%
CY 2010 deliveries -16,125 ac-ft
Figure 5-36
2010 Reclaimed water use in Tucson, Ariz.
A prominent addition to industrial water reclamation is
represented by the expansion of the Frito-Lay
production facility in Casa Grande with a 0.65 mgd (29
L/s) industrial Process Water Recovery Treatment
Plant (PWRTP) that saves 100 million gallons of water
per year. This facility and other environmental
achievements are described in a case study [US-AZ-
Frito-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.
Other 15,800
2%
Natural System
Restoration, Wetlands,
Wildlife Habitat 29,600
Recreational
Impoundment 25,800
Seawater Intrusion
Barrier 47,100
7%
Commercial 6,400
1%
Industrial 47,100
7%
Groundwater Recharge
79,700
12%
2009
669,000 acre-feet
Geothermal Energy
Production 14,900
.Golf Course Irrigation
43,600
7%
Figure 5-37
Uses of recycled water in Calif. (SWRCB 2011)
Agricultural reuse is the largest user of reclaimed
water in California. In Monterey, reclaimed water has
been used since 1998 on prime farmland to grow cool
season vegetables as part of an effort to reduce
groundwater extraction [US-CA-Monterey]. Long-term
(10-year) studies of soil salinity have been
implemented to understand how different soil types in
the region respond to the salt content of reclaimed
water. In San Diego, the North City Reclamation Plant
uses an electrodialysis reversal (FDR) system to
desalinate advanced treated reclaimed water to
provide a new source of high quality irrigation water,
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Chapter 5 Regional Variations in Water Reuse
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-CA-
Elsinore 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 I PR 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
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Chapter 5 | Regional Variations in 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 USAGE 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.
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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.
Eastern Washington has roughly twice the land area
and one-third the population of western Washington.
Pacific Northwest Region
lUS
0.0
Population
Land Use
Figure 5-38
Change in population (2000-2010) and developed land
(1997-2007) in the Pacific Northwest region, compared
to the United States
The Pacific Northwest region's population grew at 14.2
percent over the past decade, with significant
population increases in Alaska (13.3 percent), Idaho
(21.1 percent), Oregon (12.0 percent), and
Washington (14.1 percent).
Alaska has a population of 0.7 million residents,
adding about 80,000 residents over the past decade.
Idaho is the 39th most populous state with 1.6 million
residents and the 14th largest state by land area.
Oregon has 3.8 million residents. Washington State is
the 13th most populous state with 6.7 million residents.
The Cascade Range runs north-south, bisecting the
state.
5.2.8.2 Precipitation and Climate
Figure 5-39 depicts average monthly precipitation in
the Pacific Northwest region by state.
Western Washington, from the Cascades westward,
has a mostly marine west coast climate with mild
temperatures and wet winters, autumns, and springs,
and relatively dry summers. Eastern Washington, east
of the Cascades, has a relatively dry climate.
Summers are warmer, winters are colder and
precipitation is less than half of western Washington.
•Alaska
•Idaho
Oregon
•Washington
Month
Figure 5-39
Average monthly precipitation in the Pacific Northwest
region
The climate in Oregon varies greatly between the
western and eastern regions of the state. The
Columbia and Snake rivers delineate much of
Oregon's northern and eastern boundaries,
respectively. The landscape in Oregon is diverse and
varies from rain forest in the Coast Range in the
western region to barren desert in the southeast. An
oceanic climate predominates in Western Oregon, and
a much drier semi-arid climate prevails east of the
Cascade Range in Eastern Oregon. Population
centers lie mostly in the western part of the state,
which is generally moist and mild, while the lightly
populated high deserts of Central and Eastern Oregon
are much drier.
The four seasons are distinct in all parts of Idaho, but
different parts of the state experience them differently.
Spring comes earlier and winter later to Boise and
Lewiston, which are protected from severe weather by
nearby mountains and call themselves "banana belts."
Eastern Idaho has a more continental climate, with
more extreme temperatures; climatic conditions there
and elsewhere vary with the elevation. Humidity is low
throughout the state. Precipitation in southern Idaho
averages 13 in (33 cm) per year; in the north,
precipitation averages over 30 in (76 cm) per year.
Average annual precipitation (1971 to 2000) at Boise
was 12.2 in (31 cm), with more than 21 in (53 cm) of
snow. Much greater accumulations of snow are
experienced in the mountains.
Though possibly perceived as a state with high
precipitation, Alaska actually ranks as the 39th wettest
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Chapter 5 | Regional Variations in Water Reuse
state (22.70 in or 57.7 cm annually) with an annual
rainfall range from 4.16 in (10.6 cm) in Barrow on the
north coast to 75.35 in (191 cm) in Kodiak in the south.
Due to a colder climate, snowfall ranges from 30.3 in
(77 cm) per year in Barrow to 322.9 in (8.2 m) in
Valdez. The colder weather conditions limit agricultural
applications, one of the historically high uses for
reclaimed water.
5.2.8.3 Water Use by Sector
Figure 5-40 shows freshwater use by sector in the
Pacific Northwest.
Domestic self-
supply
1%
Mining
3%
Industrial _/ Aquaculture
3% 15%
Figure 5-40
Freshwater use by sector for the Pacific Northwest
region
Idaho, Oregon, and Washington have well developed
regulations and standards. Idaho's continuing efforts to
support reuse, considering the different types of land
application and treatment systems and end uses, have
led to updates in state regulations and guidance over
the years. With emphasis on in-stream water quality,
focused on nutrients and sediment, all of the sectors in
Idaho, Oregon, and Washington could anticipate
increased interest in water reuse.
5.2.8.4. States' Regulatory Context
Alaska
Alaska does not have regulations that specifically
address water reuse.
Idaho
Idaho has both reuse regulations and guidelines
whose scope includes treatment and beneficial reuse
of municipal and industrial wastewater. Water reuse by
different types of land application facilities is allowed
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
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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
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system enhances wildlife habitat while reducing
the temperature, IDS, and nutrients in
reclaimed water (CH2MHNI, 2011). In addition,
13 ac of perimeter landscaping provides the
opportunity to reuse effluent for irrigation to
support more diverse habitat. The system is first
in the nation designed to treat a unique
combination of municipal and industrial WWTP
effluents.
• City of Silverton Oregon Garden Project—
wetlands. Similar to the system in Albany, the
city of Silverton's reclaimed water is used to
create a thriving habitat through 17 acres of
terraced ponds with cascading water, pools, and
wetlands plants to a holding tank where it then
flows into an irrigation system used to irrigate a
garden (Oregon Garden, n.d.). The system
lowers the temperature and removes nitrate and
phosphorous prior to discharge in Brush Creek.
The wetlands also play an active role in the
education programs at The Garden.
Washington
There are more than 25 reclaimed water facilities
operating in Washington State—about one-third are
located in eastern Washington and two-thirds are
located in western Washington. The design capacity
for these facilities range from less than 1 mgd (43.8
L/s) to 21 mgd (920 L/s). Approximately 35 reclaimed
water facilities are in the planning or design phase.
The drivers for reclaimed water facilities in Washington
vary by facility and include discharge regulations,
impaired water bodies with TMDLs, efforts to restore
Puget Sound, opportunities due to upgrades or new
facilities with advanced treatment technologies, and
water supply needs.
Water reuse in Washington includes golf course
irrigation; urban uses, such as street sweeping;
agricultural irrigation; forest irrigation; groundwater
recharge; ASR; wetlands enhancement; stream-flow
augmentation; and commercial and industrial
processes. King County and the University of
Washington collaborated in a study to demonstrate the
safety of using Class A reclaimed water in a vegetable
garden, as detailed in a case study [US-WA-King
County]. In Sequim, a reclaimed water distribution
system uses reclaimed water for toilet flushing,
irrigation, stream augmentation, vehicle washing,
street cleaning, fire truck water, and dust control [US-
WA-Sequim], relying on a marine outfall to discharge
wastewater when the reclamation process fails and
seasonally when reclaimed water demand drops. In
Yelm, reclaimed water is used in a wetlands park to
have a highly visible and attractive focal point
promoting reclaimed water use [US-WA-Yelm]. In
addition, as part of planning for expansion of the
reclaimed water system, a local ordinance was
adopted establishing the conditions of reclaimed water
use, which includes a "mandatory use" clause
requiring construction of reclaimed water distribution
facilities as a condition of development approval.
5.3 References
Bassyouni, A., M. Sudame, and D. McDermott. 2006. "Model
Water Recycling Program." WEFTEC Conference 2006.
Water Environment Federation.
Bennett, L. 2010. "Wastewater Reclamation and Reuse
Projects in the State of Virginia, What's Happening Around
the State, VWEA/VA." AWWA Water Reuse Committee
Seminar, June 8, 2010.
City of Raleigh. 2012. Reuse Water System. Retrieved on
August 23, 2012 from
.
CH2MHNI. 2011. Talking Water Gardens Natural Water
Treatment and Reuse Project: Innovative Approach to
Complex Water Quality Issues. Retrieved on August 23,
2012 from
.
Coolweather. n.d. State Rainfall. Retrieved on August 23,
2012 from .
Elfland, C. 2010. "UNC Chapel Hill's Sustainable Water
Infrastructure: A Ten Year Journey." AWWA Sustainable
Water Management Conference, April 12, 2010.
Federal Register 77 (FR 77 2012):13496-13499, "Effective
Date for the Water Quality Standards for the State of
5-48
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Chapter 5 Regional Variations in Water Reuse
Florida's Lakes and Flowing Waters." 2012. Florida
Department of Environmental Protection (FDEP). 2011. 2070
Reuse Inventory. Florida Department of Environmental
Protection. Tallahassee, FL.
Florida Department of Environmental Protection (FDEP).
2009. Connecting Reuse and Water Use: A Report of the
Reuse Stakeholders Meetings. Florida Department of
Environmental Protection. Tallahassee, FL. Retrieved on
August 23, 2012 from
.
Florida Department of Environmental Protection (FDEP).
2012a. 2077 Reuse Inventory. Tallahassee, Florida.
Retrieved on August 23, 2012 from
.
Georgia Environmental Protection Division (GEPD). 2007.
Reuse Feasibility Analysis, EPD Guidance Document.
Atlanta, GA.
Georgia Governor's Office. 2009. Water Contingency
Planning Task Force, Findings and Recommendations.
Governor's Task Force. Atlanta, GA.
Global Water Intelligence (GWI). 2010. Municipal Water
Reuse Markets 2010. Media Analytics Ltd. Oxford, UK.
Goldenberg, B., C. Helfrich, A. Perez, A. Garcia, R.
Chalmers, and P. Gleason. 2009. "The Impact of Legislation
Eliminating the Use of Ocean Outfalls on Reuse in
Southeast Florida." WateReuse Symposium, Seattle, WA,
October 2009.
Kenny, J. F., N. L. Barber, S. S. Hutson, K. S. Linsey, J. K.
Lovelace, and M. A. Maupin. 2009. "Estimated Use of Water
in the United States in 2005." United States Geological
Survey (USGS). Retrieved on August 23, 2012 from
.
Metropolitan Area Planning Council (MAPC). 2005. "Once is
Not Enough: A Guide to Water Reuse in Massachusetts."
Retrieved on August 23, 2012 from
.
Metropolitan Council Environmental Services (MCES). 2007.
Recycling Treated Municipal Wastewater for Industrial Water
Use. A report prepared for the Legislative Commission on
Minnesota Resources, August 2007. Metropolitan Council
Environmental Services. St. Paul, MN. Retrieved August 23,
2012 from
.
Miles, W., R. Bonne, and A. Russell. 2003. "Startup and
Operation of Gary, North Carolina's Residential/Commercial
Reclaimed Water System." Virginia Water Environment
Association. Glen Allen, VA.
Miller, W. G. 2011. "Water Reuse in the U.S.A.: Current
Challenges and New Initiatives." 8th IWA International
Conference on Water Reclamation and Reuse, Barcelona,
Spain.
Miller, W. G. 2012. Personal communication by document
editors on extent of water reuse in the United States.
Minnesota Department of Natural Resources (MDNR). 2008.
Minnesota Water Appropriations Permit Program, State
Water Use Data System. Data summarized through 2007
were obtained from the MDNR. Retrieved on August 23,
2012 from
.
Minnesota Pollution Control Agency (MPCA). 201 Oa.
Biofuels: Reusing Municipal Wastewater. Retrieved on
August 23, 2012 from
.
Minnesota Pollution Control Agency (MPCA). 201 Ob.
Municipal Wastewater Reuse. Retrieved on August 23, 2012
from .
Miyamoto, S. 2004. Landscape Plant Lists for Salt Tolerance
Assessment. Texas A&M University Agricultural Research
and Extension Center. El Paso, TX.
Miyamoto, S. 2003. "Managing Salt Problems in Landscape
Use of Reclaimed Water in the Southwest." Watereuse
Symposium. Alexandria, VA.
2012 Guidelines for Water Reuse
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Chapter 5 | Regional Variations in 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.
Texas A&M University Agricultural Research and Extension
Center. El Paso, TX.
National Oceanic and Atmospheric Administration (NOAA).
n.d. National Climatic Data Center. Thirty-year annual
precipitation data. Retrieved on August 23, 2012 from
.
National Research Council (NRC) 2012. Water Reuse:
Potential for Expanding the Nation's Water Supply Through
Reuse of Municipal Wastewater. National Academy Press.
Washington, D. C.
North Carolina Administrative Code (NCAC). 2011. North
Carolina Reclaimed Water Regulations. 15A NCAC 02U.
Retrieved on August 23, 2012 from
.
Oregon Garden, n.d. "Wetlands" Retrieved on August 23,
2012 from .
Ornelas, D. and I. S. Rojas. 2007. "Managing Reclaimed
Water Concerns Attributed to Declining Water Usage." 11th
Annual WateReuse Research Conference. WateReuse
Association: Alexandria, VA.
Rosencrans, M. 2012. U.S. Drought Monitor. Retrieved on
August 31, 2012 from .
Ryan, M. D. 2006. "Design-Build of Rio Rancho's MBR
Plants-A Win-Win-Win Success." Design-Build Institute of
America, January 26, 2006. Albuquerque, NM,
S. Roberts Co. 2009. Cache Creek Desalination Facility.
Retrieved on August 23, 2012 from
.
Schenk, R. E. and D. Vandertulip. 2009. "The Next Step in
Improving Texas Reclaimed Water Projects - Proposed
Update of Chapter 210." Texas Water, April 11, 2009.
Galveston, TX.
Shakopee Mdewakanton Sioux Community (SMSC), n.d.
Shakopee Mdewakanton Sioux Community Department of
Land and Natural Resources. Retrieved on August 31, 2012
from .
Smith, D. A. and J. D. Wert. 2007. "University Area Joint
Authority Beneficial Reuse Project-20 Months of Operation."
WEFTEC 2007. San Diego, CA.
State Water Resources Control Board (SWRCB). 2011.
Water Recycling Funding Program: Municipal Wastewater
Recycling Survey. Retrieved on August 23, 2012 from
.
Texas Commission on Environmental Quality (TCEQ). n.d.
General Permits for Waste Discharges. Retrieved on
August 23, 2012 from
.
Tien, C. 2010. "Maryland Water Reuse Regulations." 19th
Maryland Ground Water Symposium, September 29, 2010.
Town of Gary. n.d. Reclaimed Water System. Retrieved on
December 27, 2012 from
.
United States Census Bureau (USCB). n.d. Resident
Population Data: 2000 and 2010. Retrieved on August 23,
2012 from
.
U.S. Department of Agriculture (USDA). 2009. Summary
Report: 2007 National Resources Inventory. Natural
Resources Conservation Service and Center for Survey
Statistics and Methodology, Iowa State University. Retrieved
on August 31, 2012 from
.
U.S. Department of the Interior, Bureau of Reclamation
(USBR). 2012. WaterSMART (Sustain and Manage
America's Resources for Tomorrow). Retrieved on August
23, 2012 from .
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). 2007. National
Nutrient Strategy. Retrieved on August 23, 2012
.
5-50
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Chapter 5 Regional Variations in Water Reuse
U.S. Environmental Protection Agency (EPA), n.d. Federal
Water Quality Standards for the State of Florida. Retrieved
on August 23, 2012 from
.
Westmiller, R. 2010. "Purple, the New Gold." Irrigation and
Green Industry. October 2010(10):26-32.
Whitcomb, J. B. 2005. Florida Water Rates Evaluation of
Single-Family Homes. Prepared for Southwest Florida Water
Management District, St. Johns River Water Management
District, South Florida Water Management District, and
Northwest Florida Water Management District. Retrieved on
August 23, 2012 from
.
WRA News. 2011. Bureau of Reclamation Awards $1.2
Million for Water Reuse Studies in Three States. Retrieved
on August 23, 2012 from
.
Wu, M., M. Mintz, M. Wang, and S. Arora. 2009.
Consumptive Water Use in the Production of Ethanol and
Petroleum Gasoline. Center for Transportation Research,
Energy Systems Division, Argonne National Laboratory.
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5-52 2012 Guidelines for Water Reuse
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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.,
California Model IPR
Surface Water (nutrients)
Namibia Model (No RO)
Gwinnett County IPR
Cloudcraft Model (MBR)
Figure 6-1
Potable reuse treatment scenarios (Chalmers et al., 2011)
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).
Media
Filtration
BAC/GAC
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
The important lesson is that now, regardless of the
end use and desired reclaimed water quality there are
technologies available to treat water to whatever level
is required for the targeted end use. In addition to
successful implementation of current advanced
treatment technologies for producing reclaimed water,
there is ongoing research into optimizing these
processes and investigating emerging technologies to
meet treatment objectives for both pathogens and
chemical constituents (WRRF, 2007a; 2012a).
6.1 Public Health Considerations
The most critical objective in any reuse program is to
protect public health and a portfolio of treatment
options exists to mitigate microbial and chemical
contaminants in reclaimed water and meet specific
water quality goals (NRC, 2012). Other objectives,
such as preventing environmental degradation,
avoiding public nuisance, and meeting user
requirements, must also be satisfied, but the starting
point remains the safe delivery and use of properly
treated reclaimed water. In order to put concerns
about protecting public health and the environment
into perspective with respect to water reclamation, it is
important to consider several key questions.
6.1.1 What is the Intended Use of the
Reclaimed Water?
Protection of public health is achieved by 1) reducing
or eliminating concentrations of pathogenic bacteria,
parasites, and enteric viruses in reclaimed water; 2)
controlling chemical constituents in reclaimed water;
and 3) limiting public exposure (contact, inhalation, or
ingestion) to reclaimed water. Reclaimed water
projects may vary significantly in the level of human
exposure incurred, with a corresponding variation in
the potential for health risks. Where human exposure
is likely, reclaimed water should be treated to a high
degree prior to its use (Table 6-1). Reclaimed water
used for irrigation of non-food crops on a restricted
agricultural site may be of lesser quality than water for
landscape irrigation at a public park or school, which
may be of a lesser quality than reclaimed water
intended to augment potable supplies. To make reuse
cost-effective, the level of treatment must be "fit for
purpose." Secondary effluent can become reclaimed
water nonpotable reuse by addition of filtration and
enhanced disinfection. Higher level uses (e.g., potable
reuse) may include additional processes, such as
membranes, advanced oxidation, or soil aquifer
treatment to remove chemical and biological
constituents.
Table 6-1 Types of reuse appropriate for increasing levels of treatment
Treatment
Level
Increasing Levels of Treatment
Primary
Processes
End Use
Human
Exposure
Cost
Sedimentation
No Uses
Recommended
Biological oxidation and
disinfection
Surface irrigation of
orchards and vineyards
Non-food crop irrigation
Restricted landscape
impoundments
Groundwater recharge of
nonpotable aquifer
Wetlands, wildlife habitat,
stream augmentation
Industrial cooling
processes
Chemical coagulation,
biological or chemical
nutrient removal, filtration,
and disinfection
Landscape and golf
course irrigation
Toilet flushing
Vehicle washing
Food crop irrigation
Unrestricted recreational
impoundment
Industrial systems
Activated carbon, reverse
osmosis, advanced
oxidation processes, soil
aquifer treatment, etc.
Indirect potable reuse
including groundwater
recharge of potable aquifer
and surface water reservoir
augmentation and potable
reuse
Increasing Acceptable Levels of Human Exposure ^^^^^
Increasing Levels of Cost ^^^^^
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
Regardless of the reclaimed water use, whether
irrigation, I PR, 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; 201 Oa).
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 full-
scale 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 by-
product NDMA, if needed; UV/AOP prior to discharge
to a surface water storage reservoir may also be
unnecessary. Excellent reduction of nitrogen and
phosphorus nutrients may be essential for reclaimed
water discharge to a storage reservoir, whereas these
nutrients represent an advantage for certain irrigation
applications and might not need to be removed.
The allowable concentrations of microbial and
chemical constituents in reclaimed water are a function
of the specific reuse application or category of reuse.
And while these requirements may vary slightly from
state to state, they have been designed to be
protective of human health given some of the current
thinking. Reclaimed water quality standards and
practices have evolved, based on both scientific
studies and practical experience. In particular,
reclamation for potable reuse will meet drinking water
standards; thus, it is not necessary to create a national
list of concentration limits for specific chemical
constituents for indirect or direct potable reuse projects
(similar to drinking water MCLs), regardless of whether
reclaimed water is part of the supply. Treatment
guidelines and drinking water health advisory-type
benchmarks for emerging chemicals of potential
interest (pharmaceuticals, pesticides, and other
"chemicals of emerging concern") are useful for
assisting engineers in design of the multiple barriers
that continue to protect the public from health risks.
6.1.3 Which Sampling/Monitoring
Protocols are Required to Ensure that
Water Quality Objectives are Being Met?
The successful record of water reuse installations is
also the result of programs that ensure treatment
reliability, establish cross-connection controls, manage
conveyance and distribution system controls, display
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
user area controls (such as signage, color-coded pipes
and appurtenances, and setback distances), and
monitor water quality to ensure safety, as described in
Chapter 4. It is also essential to have an appropriate
HACCP-type management system; to employ
appropriate, reliable, and multi-barrier redundant
treatments; and to utilize as much as possible real-
time 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.
6-4
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
Table 6-2 Infectious agents potentially present in untreated (raw) wastewater
Pathogen
Numbers in Raw
Wastewater (per liter)
Bacteria
Shigella
Salmonella
Vibro cholera
Enteropathogenic Escherichia coli
(many other types of E. coli are not harmful)
Yersinia
Leptospira
Campylobacter
Atypical mycobacteria
Legionella
Staphylococcus
Pseudomonas
Helicobacter
Protozoa
Entamoeba
Giardia
Cryptosporidium
Microsporidia
Cyclospora
Toxoplasma
Helminths
Ascaris
Ancylostoma
Necator
Ancylostoma
Strongyloides
Trichuris
Taenia
Enterobius
Echinococcus
Enteroviruses (polio, echo, coxsackie, new
enteroviruses, serotype 68 to 71)
Hepatitis A and E virus
Adenovirus
Rotavirus
Parvovirus
Shigellosis (bacillary dysentery)
Salmonellosis, gastroenteritis (diarrhea,
vomiting, fever), reactive arthritis, typhoid fever
Cholera
Gastroenteritis and septicemia, hemolytic uremic
syndrome (HUS)
Yersiniosis, gastroenteritis, and septicemia
Leptospirosis
Gastroenteritis, reactive arthritis, Guillain-Barre
syndrome
Respiratory illness (hypersensitivity pneumonitis)
Respiratory illness (pneumonia, Pontiac fever)
Skin, eye, ear infections, septicemia
Skin, eye, ear infections
Chronic gastritis, ulcers, gastric cancer
Amebiasis (amebic dysentery)
Giardiasis (gastroenteritis)
Cryptosporidiosis, diarrhea, fever
Diarrhea
Cyclosporiasis (diarrhea, bloating, fever,
stomach cramps, and muscle aches)
Toxoplasmosis
Ascariasis (roundworm infection)
Ancylostomiasis (hookworm infection)
Necatoriasis (roundworm infection)
Cutaneous larva migrams (hookworm infection)
Strongyloidiasis (threadworm infection)
Trichuriasis (whipworm infection)
Taeniasis (tapeworm infection),
neurocysticercosis
Enterobiasis (pinwork infection)
Hydatidosis (tapeworm infection)
Gastroenteritis, heart anomalies, meningitis,
respiratory illness, nervous disorders, others
Infectious hepatitis
Respiratory disease, eye infections,
gastroenteritis (serotype 40 and 41)
Gastroenteritis
Gastroenteritis
UptolO4
UptolO5
UptolO5
UptolO4
Up to 102
UptolO5
UptolO4
UptolO3
UptolO3
UptolO2
UptolO6
UptolO6
Up to 105
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
Table 6-2 Infectious agents potentially present in untreated (raw) wastewater
Numbers in Raw
Wastewater (per liter)
Viruses
Astrovirus
Caliciviruses (including Norovirus and
Sapovirus)
Coronavirus
Gastroenteritis
Gastroenteritis
Gastroenteritis
UptolO9
(Sources: NRC, 1996; Sagik et. al., 1978; Hurst et. al., 1989; WHO, 2006; Feachem et al., 1983, Mara and Silva, 1986; Oragui
etal., 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 urn to over 60
urn (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 urn to more
than 100 urn, 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 urn 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 paniculate matter or
floe particles, and these particles settle during
sedimentation, secondary clarification, or during an
advanced treatment process such as coagulation/
flocculation/sedimentation. Bacteria can also be
removed by using a filtration process that includes
sand filters, disk (cloth) filters, or membrane
processes. Bacteria can also be inactivated by
disinfection. Both filtration and disinfection are
discussed further in Section 6.4.
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6.2.1.3 Viruses
Viruses occur in various shapes and range in size from
0.01 to 0.3 |jm, 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 |jm 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
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of special studies or by proactive utilities that wish to
confirm the treatment reliability of the process used to
produce reclaimed water. More often, indicators
including total coliforms; fecal coliforms, a subset of
total coliforms; Escherichia coli (E. coli); enterococci;
and coliphage are used to validate performance of
treatment and the quality of the final reclaimed water
quality. The main drawback to using microbial
indicators is that they are somewhat limited in their
ability to predict the presence of pathogens. Also, all
current uses of microbial indicators employ cultivation
methods that delay results for at least 24 hours. For
example, nonpathogenic coliforms, such as those that
may be found in soil, can grow in water under certain
conditions, leading to positive results that may not be
indicative of wastewater impact. Additionally, coliform
bacteria do not adequately reflect the occurrence of
pathogens in disinfected reclaimed water due to their
relatively high susceptibility to chemical disinfection
and failure to correlate with protozoan parasites such
as Cryptosporidium and enteric viruses (Bonadonna,
et al., 2002; Havelaar et al., 1993).
Alternative microbiological indicators have been
suggested for evaluation of wastewater, drinking
water, and environmental waters, including
Enterococcus, Clostridium, and coliphages. But there
have been only a few studies of reclaimed water in
which the levels of indicator organisms have been
directly compared to those of viral, bacterial, or
protozoan pathogens at each stage of treatment, and
additional research on this topic is needed (Harwood
et al., 2005). Analytical methods for actual pathogen
monitoring continue to evolve, and recent studies have
not relied solely on the traditional standard culture
methods (Fox and Drewes, 2001; Sloss et al., 1996;
Sloss et al., 1999; Yanko 1999). PCR is now
commonly used to study pathogens and indicators by
detecting the DNA or RNA in the environment. PCR is
useful because the methods are sensitive. In addition,
PCR can be much less expensive and time consuming
than traditional pathogen methods, and culture
methods are not currently available for some
pathogens. Recent studies have reported pathogen
DNA and RNA in secondary and advanced municipal
wastewater effluents, some recycled water,
groundwater, and in ocean water impacted by
wastewater discharges (Aw and Gin, 2010; De Roda
et al., 2009; Hunt et al., 2010; Jjemba et al., 2010;
Symonds et al., 2009, da Silva et al., 2008; da Silva et
al., 2007; Haramoto et al, 2007). However, it is
important to emphasize that PCR does not determine
pathogen viability or infectivity; it only indicates the
existence of DNA or RNA derived from the
microorganisms. There is ongoing research using
PCR-based detection methods into how this
information can be used to evaluate potential risk;
quantitative PCR in particular has potential to provide
data for quantitative microbial risk assessment
(QMRA), however, it must be kept in mind that
indicators only evaluate "potential" risk. These
indicators have not been related to any
epidemiological risks except for E, coli and enterococci
in recreational settings (Section 6.3.1). Additionally,
evaluation of certain disinfection processes is
particularly limited with respect to using molecular
tools and indicators, although molecular viability
methods are emerging.
6.2.1.6 Removal of Microorganisms
Removal of indicators and pathogens can be
demonstrated both by challenge testing and
operational monitoring. Challenge testing allows large
log removals to be demonstrated by spiking influent
concentrations with higher than normal microorganism
concentrations to allow detection in the effluent.
Because detected concentrations of actual pathogens
tend to approach or fall at the lowest detectable
concentrations of current analytical methods, further
research in this area could provide greater confidence
in the sensitivity of operational monitoring. Table 6-3
presents an indicative range of microbial log
reductions reported in the literature for different
treatment processes, which are further discussed in
Section 6.4. These ranges are intended to present
relative removals; they should not be used as the
basis of design for treatment schemes.
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Table 6-3 Indicative log removals of indicator microorganisms and enteric pathogens during various stages of
wastewater treatment
Bacteria
Protozoa and helminths
Viruses
X
X | | X |
X
X
X
X
X
Indicative Log Reductions in Various Stages of Wastewater Treatment
Secondary treatment
Dual media filtration2
Membrane filtration (UF,
NF, and RO)3
Reservoir storage
Ozonation
UV disinfection
Advanced oxidation
Chlorination
1 -3
0-1
4->6
1 -5
2-6
2- >6
>6
2->6
0.5-1
0-1
>6
N/A
0-0.5
N/A
N/A
1 -2
0.5-2.5
1 -4
2->6
1 -4
2-6
3- >6
>6
0-2.5
1 -3
0-1
>6
1 -5
2-6
2 ->6
>6
2->6
0.5-2
0.5-3
2->6
1 -4
3-6
1 ->6
>6
1 -3
0.5-1.5
1 -3
>6
3-4
2-4
3- >6
>6
0.5-1.5
0.5-1
1.5-2.5
4->6
1 -3.5
1 -2
3- >6
>6
0-0.5
0-2
2-3
>6
1.5->3
N/A
N/A
N/A
0-1
(Sources: Bitton, 1999; EPHC, 2008; Mara and Horan, 2003; NRC, 1998; NRC, 2012; Rose et al., 1996; Rose, et al.,
2001; EPA, 1999, 2003, 2004; WHO, 1989)
1 Reduction rates depend on specific operating conditions, such as retention times, contact times and concentrations of
chemicals used, pore size, filter depths, pretreatment, and other factors. Ranges given should not be used as design or
regulatory bases—they are meant to show relative comparisons only.
Including coagulation
3Removal rates vary dramatically depending on the installation and maintenance of the membranes.
N/A = not available
6.2.1.7 Risk Assessment of Microbial
Contaminants
While most microbes are harmless or beneficial, some
are extremely dangerous—these are sometimes
referred to as biological agents of concern (BAG). All
BAG 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 BAG (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
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duration of exposure by each pathway as well as
estimate the number of people exposed and the
categories of people affected.
Risk Characterization: The final step of the process
integrates information from previous steps into a single
mathematical model to calculate risk—the probability
of an outcome such as infection, illness, or death.
Because the first three steps do not provide a single
value but instead offer a range of values for exposure,
dose, and hazard, risk needs to be calculated for all
values across those ranges. This is accomplished
using Monte Carlo analysis, and the result is a full
range of possible risks, including average and worst-
case 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 clay-
bearing soils, and affect soil structure. Salinity also can
cause aesthetic concerns (e.g., taste in potable reuse
or residues in car washing operations), scaling, and
corrosion. Salinity can be removed in treatment, but
options tend to be costly, and liquid waste (brine)
disposal is an issue. Salinity management in irrigation
reuse applications is described further in Chapter 3.
Oxyhalides. Oxyhalides of concern in water reuse
include bromate, chlorate, and perchlorate. Bromate
can be created when bromide-containing wastewater
is ozonated; therefore, treatment facilities must be
designed and operated properly to minimize oxyhalide
formation during treatment. Bromate, chlorate, and
perchlorate can be derived from household bleach.
Perchlorate, a component of propellants, can
bioaccumulate in certain plants and must be managed
in irrigation.
Nutrients. Nitrogen and phosphorus from human
waste products can pose environmental and health
concerns but can also be beneficial in certain irrigation
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applications. Therefore, the need to remove nutrients
during treatment for reuse depends on the intended
use of the product water.
Engineered Nanomaterials. Nanomaterials are
materials with morphological features on the
nanoscale (1 nm = 10-9 m), that often have special
properties stemming from their dimensions.
Nanomaterials have one or more dimensions ranging
from 1 to 100 nm: nanofilms (one dimension),
nanotubes (two dimensions), and nanoparticles (three
dimensions). Larger particles, such as zeolites (1,000
to 10,000 nm, or 1 to 10 urn), 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
malodorous and impart color to the water.
be
Clogging. Paniculate 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.
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• Disinfection effects. Organic matter can
interfere with chlorine, ozone, and UV
disinfection, thereby making them less available
for disinfection purposes. Further, chlorination
may result in formation of potentially harmful
chlorinated DBPs.
• Health effects. Ingestion of water containing
certain organic compounds may result in acute
or chronic health effects.
The detection of a variety of organic chemicals in
municipal wastewater effluent has raised concerns
about the potential presence of wastewater-derived
chemical contaminants in reclaimed water as well as
about their health effects. And, for some reuse
applications, regulatory agencies and utilities have
struggled with this issue of wastewater-derived
compounds, some of which are often present at
extremely low concentrations. Because many of these
compounds are not currently regulated, current
research has focused on the composition of highly
processed wastewaters to identify residual chemicals
that might be a health concern, determine what studies
would be needed as a basis for risk assessment, and
develop lists of compounds for which more information
is needed to assess the potential human health
concerns (WRRF, 2012e). Additionally, the WRRF has
funded work on identification and validation of
surrogate parameters and analytical methods for
wastewater-derived contaminants to predict removal of
wastewater-derived contaminants in reclaimed-water
treatment systems (WRRF, 2008).
Parameters that have historically been used for this
purpose and can serve as aggregate measures of
organic matter include TOC, dissolved organic carbon
(DOC) (that portion of the TOC that passes through a
0.45-um pore-size filter), paniculate 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 bromine-
substituted 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 by-
product 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 UV-
AOP for treatment of RO permeate to address NDMA
[US-CA-Vander Lans; US-CA-Orange County; US-CA-
San Diego].
6.2.2.3 Trace Chemical Constituents
Sophisticated analytical instrumentation makes it
possible to identify and quantify extremely low levels of
individual inorganic and organic constituents in water.
Examples include gas chromatography/tandem mass
spectrometry (GC/MS/MS) and high-performance
liquid chromatography/mass spectrometry (HPLC/MS).
These analyses are costly and may require extensive
and difficult sample preparation, particularly for
nonvolatile organics. Advancements in these and other
analytical chemistry techniques have enabled the
quantification of chemicals in water at parts per trillion
(ppt) and even parts per quadrillion levels. With further
analytical advancements, nearly any chemicals will be
detectable in environmental waters, wastewater,
reclaimed water, and drinking water in the future, but
the human and environmental health relevance of
detection of diminishingly low concentrations remains
a greater challenge to evaluate.
As analytical techniques have improved, a number of
anthropogenic chemical compounds that are not
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commonly regulated have been detected in drinking
water, wastewater effluent, or environmental waters,
generally at very low levels. Detection of these
compounds does not imply that they have been
recently released to the environment—many have
likely been in the environment for decades. This broad
group of individual chemicals and classes of
compounds present at trace concentrations is
sometimes termed contaminants of emerging concern
(CECs), TrOCs, or microconstituents. This broad
group of CECs can include groups of compounds
categorized by end use (e.g., Pharmaceuticals,
nonprescription drugs, personal care products,
household chemicals, food additives, flame retardants,
plasticizers, and biocides), by environmental and
human health effect, if any (e.g., hormonally active
agents, endocrine disrupters [EDs], or endocrine
disrupting compounds [EDCs]), or by type of
compound (e.g., chemical vs. microbiological, phenolic
vs. polycyclic aromatic hydrocarbons). Contaminants
under these sub-groupings that are not regulated
under national drinking water standards may be on the
Drinking Water Contaminant Candidate List (CCL),
including some known EDCs, which include chemicals
shown to disrupt animal endocrine systems, as well as
those with adverse human health interactions. Table
6-4 provides categories of compounds which may be
detectable in reclaimed water.
Although trace chemical constituents are "pollutants"
when they are found in the environment at
concentrations above background levels, they are not
necessarily "contaminants" (that is, found in the
environment at levels high enough to induce ecological
and/or human health effects). Experts have struggled
to agree on a term that captures the range of
constituents because the public often finds terms such
as CEC confusing or alarming, as described in
Chapter 6. However, describing the numerous
constituents by sub-group or as individual chemicals
can likewise cause confusion, because these are also
not well understood by the general public. Debate and
discussion is ongoing in the water community about
how to discuss trace chemical compounds, including
terminology and relative risk.
Removal of Trace Chemical Constituents. As
reclaimed water is considered a source for more and
more uses, including industrial process water or
potable supply water, the treatment focus has
expanded far beyond secondary treatment and
disinfection to include treatment for other
contaminants, such as metals, dissolved solids, and
trace chemical constituents.
Chemical constituents are amenable to treatment
depending on the physiochemical properties of the
compounds and the removal mechanisms of particular
treatment processes. EPA has released a report with
results of an extensive literature review of published
studies of the effectiveness of various treatment
technologies for CECs (EPA, 2010). The results of this
literature review are also available in a searchable
database, "Treating Contaminants of Emerging
Concern—A Literature Review Database" (EPA,
2010). EPA developed this information to provide an
accessible and comprehensive body of historical
information about current CEC treatment technologies.
Given the wide range of properties represented by
trace chemical constituents, there is no single
treatment process that provides an absolute barrier to
all chemicals. To minimize their presence in treated
water, a sequence of diverse treatment processes
capable of tackling the wide range of physiochemical
Table 6-4 Categories of trace chemical constituents (natural and synthetic) potentially detectable in reclaimed water
and illustrative example chemicals (NRC, 2012)
End use Category I Examples
Industrial chemicals
Pesticides, biocides, and herbicides
Natural chemicals
Pharmaceuticals and metabolites
Personal care products
Household chemicals and food
additives
Transformation products
1,4-Dioxane, perflurooctanoic acid, methyl tertiary butyl ether, tetrachloroethane
Atrazine, lindane, diuron, fipronil
Hormones (17(3-estradiol), phytoestrogens, geosmin, 2-methylisoborneol
Antibacterials (sulfamethoxazole), analgesics (acetominophen, ibuprofen), beta-
blockers (atenolol), antiepileptics (phenytoin, carbamazepine), veterinary and
human antibiotics (azithromycin), oral contraceptives (ethinyl estradiol)
Triclosan, sunscreen ingredients, fragrances, pigments
Sucralose, bisphenol A (BPA), dibutyl phthalate, alkylphenol polyethoxylates, flame
retardants (perfluorooctanoic acid, perfluorooctane sulfonate)
NDMA, HAAs, and THMs
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
properties is needed (Drewes and Khan, 2010). Full-
scale 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 (Miege et al., 2008).
Some removal or chemical conversion can be
expected during drinking water disinfection (i.e.,
sulfamethoxazole, trimethoprim estrone, 17p-estradiol,
17a-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 etal., 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
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
potential human health risks of unknown and
unidentified trace level chemicals in reclaimed water
(Nellor et al., 1984; Sloss et al., 1996; Anderson et al.,
2010), there is currently no definitive documentation of
risk with respect to trace chemicals for the use of
reclaimed water to augment drinking water supplies.
On the basis of available information, there is no
indication that health risks from using highly-treated
reclaimed water for potable purposes are greater than
those from using existing water supplies (NRC, 2012).
A recent report by the Global Water Research
Coalition (GWRC) synthesized results of nine recently
published reports addressing the occurrence and
potential for human health impacts of Pharmaceuticals
in the drinking water system (GWRC, 2009). The
report concludes that there is no known impact on
human health due to pharmaceutical exposure in
drinking water, and that if a person consumed drinking
water with the reported levels of Pharmaceuticals, that
person would consume only 5 percent (or less) of one
daily therapeutic dose (i.e., a single pill) of an
individual pharmaceutical over his or her whole
lifetime. Further, a recent report from a WHO expert
panel concluded that the risk of adverse human health
effects from exposure to the trace levels of
Pharmaceuticals in drinking water is considered to be
unlikely (WHO, 2011); this report did not assess
nonpharmaceutical trace chemicals.
Public exposure to trace chemical constituents in
water reuse for irrigation or other types of nonpotable
reuse is negligible. In planned potable reuse, the
treatment technologies employed in the United States
ensure that concentrations of trace chemicals are at
extremely low levels, often below analytical detection
limits. And, in fact National Academy of Sciences 2012
Report on water reuse (Water Reuse: Expanding the
Nation's Water Supply Through the Reuse of
Municipal Wastewater) presented a risk comparison
between potable reuse projects and de facto reuse
scenarios (as described in Section 3.7), concluding
that potable reuse scenarios have reduced risk of
pathogen exposure and lower or equivalent risk of
chemical contaminant exposure compared to existing
water supplies (NRC, 2012).
While the risk associated with trace chemical
constituents in drinking water is indeed very low, the
water sector continues to investigate the issue and
invest in precautionary treatment technologies.
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, 201 Ob).
Thus, while many environmental monitoring programs
are underway, toxicological studies conducted at
environmentally relevant concentrations are not likely
to provide much information due to the very low
hypothetical risks at the trace concentrations that are
detected, the difficulty in conducting chronic studies,
and the large margins of exposures.
In response to uncertainties that may be associated
with potential risks in potable reuse applications,
adoption of appropriate treatment technologies has
been employed to minimize exposure of humans to
wastewater-derived trace chemical constituents. Many
analytical studies have been conducted to identify the
few residual chemicals that may pass through
advanced treatment. Residual TOC levels, which can
be considered a surrogate for trace chemical
constituents in planned potable reuse finished water,
are usually a fraction of a milligram per liter.
Additional information on guidance for developing
monitoring programs that assess potential CEC threats
from water reuse provided by the SWRCB is provided
in the regulatory section that follows, Section 6.3
(SWRCB, 2011; Anderson et al., 2010). Additional
research on evaluating and explaining the relative
human health risks related to the reuse of reclaimed
water continue to be funded, and in 2012 the WRRF
published a series of reports in which quantitative
relative risk assessments were conducted at the
Montebello Forebay [US-CA-Los Angeles County].
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Chapter 6 Treatment Technologies for Protecting Public and Environmental Health
Table 6-5 Indicative percent removals of organic chemicals during various stages of wastewater treatment
Treatment
Percent Removal
Pharmaceuticals
Hormones
Antibiotics
PCT Steroid2 Anabolic3 Fragrance
NDMA
Secondary
(activated sludge)
Soil aquifer
treatment
Aquifer storage
Microfiltration
Ultrafiltration/
powdered activated
carbon (PAC)
Nanofiltration
Reverse osmosis
PAC
Granular activated
carbon
Ozonation
Advanced oxidation
High-level ultraviolet
Chlorination
Chloramination
nd
nd
nd
nd
nd
>80
>80
>80
>80
>80
50-80
10-50
nd
50-90
<20
>90
50-80
>95
20->80
>90
>95
50-80
20->80
>80
<20
nd
nd
10-50
<20
>90
50-80
>95
50-80
>90
50-80
50-80
<20
20-50
<20
-
25-50
-
<20
>90
50-80
>95
50-80
>90
50-80
>80
20-50
-<20
<20
10-50
>90
50-90
<20
>90
50-80
>95
20-50
>90
>95
>80
>80
>80
50-80
>90
>90
50-90
<20
>90
50-80
>95
<20
>90
50-80
>80
20-50
<20
<20
nd
>90
Nd
<20
nd
50-80
>95
50-80
>95
>80
>80
>80
>80
>90
>90
>90
<20
>90
50-80
>95
50-80
>90
>95
>80
>80
>80
>80
nd
nd
nd
nd
nd
50-80
>95
50-80
>80
>80
20-50
<20
<20
50-90
>90
-
<20
>90
50-80
>95
50-80
>90
50-90
50-80
nd
20->80
<20
-
>90
-
>90
25-50
>90
50-90
>90
>90
-
(Sources: Ternes and Joss, 2006; Snyder et al., 2010)
B(a)p = benz(a)pyrene; CBZ = carbamazepine, DBP = disinfection by-product; DCF
nitrosodimethylamine; nd = no data; PAC = powdered activated carbon; PCT = paracetamol.
1 erythromycin, sulfamethoxazole, triclosan, trimethoprim
2ethynylestradiol; estrone, estradiol and estriol
3 progesterone, testosterone
= diclofenac; DZP = diazepam; IBP = ibuprofen; NDMA=N-
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The Montebello Forebay project is a potable reuse
project that meets drinking water standards for
chemical constituents. The second part of this
research extended into identifying safe exposure
concentrations for a broad range of chemicals of
interest to the recycled water community based on
published toxicity information; the final task of this
work included identification of contaminants that would
be a concern in 5 to 20 years (WRRF, 201 Oc, 2011 a,
and 20120- 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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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
necessary for developing and maintaining adequate
processes to prevent contamination of groundwater
and other water sources. Together, these studies
established the role of each unit process in ensuring
treatment efficiency. Many state guidelines and
regulations emphasize the use of a multiple-barrier
approach that combines several unit processes to
ensure redundancy. Title 22 of the California Code of
Regulations for Water Recycling Criteria (Title 22)
(2009) and in Chapter 62-610 of the Florida
Administrative Code for Reuse of Reclaimed Water
and Land Application (2009) both require a multi-
barrier 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 water-
contact 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 multiple-
barrier 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
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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 properly-
designed 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. co//, 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
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
effluent guidelines and secondary and advanced
treatment are beneficial for reducing loadings of many
chemicals. Moreover, with thousands of chemicals
potentially present in reclaimed water, compiling a
comprehensive list of chemicals that could be present
in trace concentrations is not feasible. In fact, EPA
considered a select number of trace chemical
constituents on their most recent Candidate
Contaminant List (CCL3) and the proposed
Unregulated Contaminants Monitoring Rule 3
(UCMR3) for drinking water. In the absence of federal
mandates, individual states may choose to regulate
individual chemical constituents. The WHO concluded
that WHO guidelines were not necessary for
Pharmaceuticals in water supplies, and it did not
recommend general monitoring of water supplies for
Pharmaceuticals (WHO, 2011).
Extensive regulations for trace chemical constituents
in recycled water for potable applications and drinking
water are probably neither feasible nor necessary.
Treatment specifications or guidelines for particular
end uses, such is the approach for all U.S. drinking
water supplies, may be useful. However, benchmarks
for water quality composition are useful for decision-
makers 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 etal., 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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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, 17(3-
estradiol, 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 (NHMRC-
NRMMC, 2004; EPHC, 2008; and Snyder et al., 2010).
6.4 Wastewater Treatment for Reuse
The level of wastewater treatment required for any
project depends on the end use or discharge location,
but in the United States, all wastewater is required to
be treated to secondary levels, at a minimum.
Secondary treatment is designed to achieve removal
of degradable organic matter and suspended solids.
Filtration and disinfection provide additional removal of
pathogens and nutrients, and AOPs can target trace
chemical constituents. Wastewater treatment from raw
to secondary is well understood and covered in great
detail in other publications, such as the WEF Manual
of Practice (MOP) 8, Design of Municipal Wastewater
Treatment Plants (WEF, 2010). The discussion here is
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limited to treatment processes with a particular
application to water reuse and reclamation, which also
includes source control.
For many uses of reclaimed water, appropriate water
quality can be achieved through conventional, widely-
practiced 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 pass-
through. 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 sewer-
use 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 I PR projects, source
control programs may go beyond the minimum federal
requirements. Many agencies have developed local or
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statewide "no drugs down the drain programs" and/or
drug take-back programs. For example in Texas,
SAWS has developed a collection program for unused
medications. Other agencies have included additional
program elements to enhance their pollution
prevention efforts; the OCSD, which provides
reclaimed water to the OCWD for the Groundwater
Replenishment System Project in southern California,
has instituted additional program elements that build
on the agency's traditional source control program.
These elements include a pollutant prioritization
scheme that includes chemical fate assessment for a
broad range of chemicals; an outreach program for
industries, businesses, and the public; and a toxics
inventory that integrates a geographical information
system and chemical fact sheets. The OCSD
successfully used its source control program to reduce
the discharge of NDMA and 1,4-dioxane from
industries into its wastewater management system.
Oregon has passed rules that set trigger levels for
pollutants, requiring municipal wastewater facilities to
develop toxics reduction plans for listed priority
persistent pollutants if any of the pollutants are found
in their effluent above the trigger levels set by the rule
(Oregon DEQ, n.d.). The rule includes numeric effluent
concentration values for 118 priority persistent
pollutants for which drinking water MCLs have not
been adopted, but that the Oregon Environmental
Quality Commission has determined should be
included in a permitted facility's toxic-pollutant
reduction plan. The list includes pollutants that persist
in the environment, and pollutants that accumulate in
animals. All of the pollutants on the list have the
potential to cause harm to human health or aquatic
life; some are known carcinogens and others are
believed to disrupt endocrine functions. The list
includes both well-studied pollutants that people have
worked to reduce for many years and others for which
little information exists. Results of wastewater effluent
monitoring will be compared against trigger levels, and
where effluent concentrations exceed the trigger level,
the facility will be required to develop a toxics
reduction plan aimed at reducing levels of that
pollutant in its discharge. The Oregon DEQ consulted
with a Science Peer Review Panel to develop the list
of pollutants and triggers.
6.4.2 Filtration
Filtration removes particulates, suspended solids, and
some dissolved constituents, depending on the filter
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
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or sodium hypochlorite is allowed under stipulated
conditions. All other filtration and disinfection
technologies must undergo rigorous third-party testing
and receive "conditional acceptance" from the CDPH
prior to use. For filtration testing, this includes long-
term 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 compressible-
media 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
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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
Table 6-6 Summary of filter type characteristics1
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 [US-
CA-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
Filter Type Filtration Driving Force Nominal Pore Size, urn Contaminants targeted
Jr 3 for removal
Depth
Non-Compressible Media
Compressible Media
Gravity or pressure differential
60-300
TSS, turbidity, some protozoan
oocysts and cysts
Surface Filtration
Surface Filtration
Gravity
5-20
TSS, turbidity, some protozoan
oocysts and cysts
Membrane2
Microfiltration
Ultrafiltration
Nanofiltration
Reverse Osmosis
Pressure differential
Pressure differential
Pressure differential
Pressure differential
0.05
0.002-0.050
<0.002
<0.002
TSS, turbidity, some protozoan
oocysts and cysts, some bacteria
and viruses
Macromolecules, colloids, most
bacteria, some viruses, proteins
Small molecules, some
hardness, viruses
Very small molecules, color,
hardness, sulfates, nitrate,
sodium, other ions
Information taken from California Department of Public Health (2012), Metcalf & Eddy (2003)
Information from Water Treatment Membrane Processes (AWWA, 1996)
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contaminants, including pesticides, EDCs, and
Pharmaceuticals, although the degree to which
biological activity contributes to treatment performance
varies (Bonne et al., 2006; Wunder et al., 2008; Van
der Aa et al., 2003). Several types of biofiltration can
be used, including slow sand, rapid-rate, and granular
activated carbon (GAC) (Evans, 2010).
Depending on the pore size of the filter media,
substantial removal of trace chemical compounds can
be obtained. The mechanisms of physical removal
include removal of particles with sorbed chemicals,
removal of chemicals by sorption into media pores, or
electrostatic repulsion (WRRF, 2012a; Kimura et al.,
2003). Biofiltration, which is commonly used in potable
reuse schemes, enhances the use of common
physical and chemical means to remove contaminants
through biodegradation. With increasing interest in
obtaining higher quality reclaimed water, biofiltration,
as part of a multi-barrier treatment process, could
replace higher energy processes such as RO in
certain applications (see sections 3.1 and 3.7 for the
Namibia model for potable reuse).
Slow Sand Filtration. Slow sand filtration, along with
natural filtration processes, such as SAT and riverbank
filtration, which are discussed in Section 6.4.5, is
actually one of the oldest drinking water treatment
processes still being used today. Slow sand filtration
uses small-diameter sand with low surface-loading
rates without chemical coagulation. In slow sand
biofiltration, the sand's top surface becomes coated
with a biologically active layer called a schmutzdecke,
which is periodically scraped off or harrowed to renew
a system's hydraulic capacity. Although slow sand
filtration primarily uses both physical and biological
mechanisms to remove contaminants, the biological
mechanism dominates.
Rapid-Rate Filtration. Rapid-rate filtration uses
larger-diameter media, such as sand and anthracite,
and surface loading rates about 100 times higher than
slow sand filtration. A coagulant, such as ferric
chloride or alum, is added upstream of the process to
remove turbidity and organic matter. The filter must be
backwashed periodically with chlorinated or
nonchlorinated water. A preoxidation process that
uses ozone, chlorine, chlorine dioxide, or
permanganate is sometimes used, which can enhance
biological activity by oxidizing complex organic matter
into smaller, more biodegradable organic compounds
that are readily removed by a rapid-rate filter.
GAC Filtration. When compared with sand or
anthracite media, GAC has the additional property of
adsorption and can accumulate greater microbial
biomass (or biofilm) on activated carbon media.
Biomass plays an important role in biodegrading
contaminants and supplementing GAC filtration. GAC
lifetime—the time between media replacements—can
be extended by biological processes. Therefore, GAC
filtration uses physical and biological processes for
contaminant removal. Depending on contact time
requirements to remove target contaminants, GAC
filtration can be designed as a GAC rapid-rate filter, a
mono-media deep-bed contactor, or a filter cap on top
of a sand or anthracite filter bed. As with conventional
rapid-rate filters, upstream coagulants and oxidants
frequently are used to improve contaminant removal.
Additionally, GAC's adsorptive properties aids in
producing the desired filtered water quality through
adsorption; thus, GAC must be regenerated
periodically, particularly where adsorption may play a
more dominant treatment role than the biological
mechanism of contaminant removal.
6.4.3 Disinfection
Relative removal of microbial indicators and pathogens
by various treatment stages is included in Table 6-3;
however, in order to provide reclaimed water that
meets the intended use, disinfection using one or more
of these technologies is an important part of any reuse
scheme. Disinfection is designed to inactivate
microorganisms, including viruses, bacteria, protozoan
oocysts and cysts, and helminthes; these pathogenic
organisms and the associated health risks were
discussed in Section 6.2.1. The most common
reclaimed water disinfection method in use to date is
chlorination. UV disinfection is a well-proven and
commonly-used alternative to chlorine. Other
disinfection alternatives are peracetic acid (PAA),
ozone, pasteurization, and ferrate (WERF, 2008); PAA
is not discussed further because no municipal reuse
applications have been implemented in the United
States, to date.
To date, California is the only state that has
technology-based regulations for disinfection, although
Florida references the NWRI UV Guidelines in its
regulatory code as guidance for permitting reuse
applications (NWRI, 2003). Thus, while there are many
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disinfection technologies that show promise for reuse
applications, this section covers those technologies
that have demonstrated pathogen reduction through
rigorous research and have obtained "conditional
acceptance" from the CDPH for use on reclaimed
water treatment, with the exception of ferrate, which is
also included. There are four technologies accepted by
the CDPH: chlorination, UV disinfection, ozone, and
pasteurization. Dose requirements for these
disinfection technologies under California Title 22 are
provided in Table 6-7, along with comparative dose
requirements for reuse in Florida under FAC 62-610.
6.4.3.1 Chlorination
Chlorine disinfection may be accomplished using free
chlorine or chloramines. Regardless of the mode of
chlorination, the efficiency of chlorine disinfection
depends on the water temperature, pH, degree of
mixing, time of contact, presence of interfering
substances, concentration and form of chlorinating
species, and nature and concentration of the
organisms to be destroyed. In general, bacteria are
less resistant to chlorine than viruses, which, in turn,
are less resistant than parasite ova and cysts.
Disinfection requirements often include monitoring of
total chlorine (which includes free chlorine,
chloramines, and other chlorine/organic compounds)
remaining in the treated water after a certain contact
time. When ammonia is present in wastewater, it will
combine with free chlorine to form chloramines
(typically monochloramine), which is less effective as a
disinfectant than free chlorine and requires a
disinfectant dose an order of magnitude or more than
free chlorine (WEF, 2010). Additionally, chlorine reacts
with other organic constituents that remain in treated
wastewater to form compounds that provide a
measurable combined chlorine residual, but with a
potentially low disinfection capability. The occurrence
and effects of this phenomenon have been well
documented (Black and Veatch, 2010; Szerwinski, et
al., 2012).
Chlorine disinfection efficacy is typically measured as
CrT, which is the product of the total chlorine residual
times the contact time. Methods of calculating CrT can
vary. The CDPH, for example, specifies the CrT
concept, with Cr being the total combined residual and
T being the contact time at the point of measurement.
CrT can also be defined as the integration of the
residual concentration of the disinfectant concentration
CrT over the measured contact time T. Depending on
water quality and chemistry, there may be a significant
chlorine demand that yields a difference in the applied
and residual concentration at the required or
recommended contact time. Because of the
complications in wastewater, the chlorine CrT values
required for various rates of inactivation must be
determined empirically. Many studies have shown that
a CrT for free chlorine outperforms the same CrT for
chloramines; however, the assumption that a lower
dose may be required for disinfection using free
chlorine is misleading, because achieving free chlorine
residual in wastewater effluents can be challenging for
the reasons given above. Planners and designers are
cautioned to confirm the currently-accepted calculation
approach for any specific project.
Table 6-7 California and Florida disinfection treatment-based standards for tertiary recycled water and high-
level disinfection
Disinfection Process California Florida
Chlorination
UV
Ozone
Pasteurization
450 mg-min/L CrT1
100 mJ/cm2 following sand or cloth
filtration; 80 mJ/cm2 following MF or
UF; 50 mJ/cm2 following RO
1 mg-min/L CT1
1 0 second contact time at 1 79 degrees
F
25 mg-min/L for fecal coliform <1 ,000 MPN/1 00 mL
40 mg-min/L for fecal coliform 1 ,000 to <1 0,000
MPN/1 OOmL
1 20 mg-min/L for fecal coliform >1 0,000 MPN/1 OOmL
No uniform standard
No standard
No standard
1CT 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.
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.
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Free and combined chlorine have measurable
differences in disinfection ability. Free chlorine is a
rapid and effective viral disinfectant in wastewater, but
a moderate concentration of ammonia results in a
combined residual with reduced disinfection potential
for poliovirus and MS2 coliphage (MS2) (Cooper,
2000). In California, for example, the CrT of 450 mg-
min/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 mg-
min/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 paniculate matter, partially or wholly protecting them
from the UV light (Paraskeva et al., 2002; Emerick et
al., 1999). Particle size distribution may indicate the
potential for UV disinfection efficiency, with smaller
particles having less effect on UV efficiency than larger
particles, as the shielding effect is reduced (Jolis et al.,
2001); particles larger than 10 microns in size can
shield microorganisms from disinfection by UV light.
UV disinfection is enhanced by filtering water prior to
disinfection, both by the reduction in particulates (a
reduction in the number of large particles with
embedded and shielded microorganisms) and by the
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increase in UVT (a reduction in smaller particulates
that do not shield organisms but do reduce UVT and
thus reduce UV efficiency).
Chevrefils et al. (2006) provide a thorough review of
the literature on bacteria, virus, and protozoa
disinfection with UV and clearly shows that UV is a
powerful disinfectant for most microorganisms,
including viruses such as poliovirus, calicivirus,
reovirus, coxsackievirus, rotavirus, and hepatitis.
Typically, UV systems are designed to meet
regulations for bacterial indicator organisms; thus, total
and/or fecal coliform bacteria are the primary
regulatory targets. For instance, California's regulated
total coliform level for "tertiary recycled water" reuse is
2.2 cfu per 100 ml_ of water (cfu/100 ml_), which can
be obtained at a relatively low UV doses (-35 to -75
mJ/cm2), but higher doses are required to meet the 5-
log virus requirement (100 mJ/cm2) (NWRI, 2003). UV
dose is measured in millyoules 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 lower-
cost UV installation at reasonable energy use values.
It is not uncommon for UV systems to have lower
construction and operational costs compared to the
costs for sodium hypochlorite.
For those states where UV dose is regulated (e.g.,
California, Washington, Hawaii), UV systems must be
either pre-validated or undergo on-site validation after
construction. The validation process consists of
detailed third-party research of individual UV reactors
over the range of potential operating conditions. For
UV equipment that is to be used for reuse applications
in California, validation must adhere to the
requirements in Title 22 to receive conditional approval
from the CDPH. The CDPH requires detailed testing
and operation in accordance with the National Water
Research Institute's (NWRI) Ultraviolet Disinfection
Guidelines for Drinking Water and Water Reuse
(NWRI UV Guidelines). The NWRI UV guidelines
apply specifically to the disinfection of wastewater
meeting the definition of "filtered wastewater" in
California's Water Recycling Criteria (WRC), Title 22,
Division 4, Chapter 3, of the California Code of
Regulations. The NWRI UV Guidelines present
guidance such that after disinfection, the disinfected
filtered reclaimed water is essentially pathogen free,
meeting the requirement of 5-log poliovirus inactivation
and a 7-day median total coliform of 2.2 MPN/100 mL.
Additionally, the NWRI UV guidelines were recently
revised and its publication was announced in August
2012, during final preparation of this document. The
key revisions with respect to reclaimed water
incorporated into the 2012 version include (NWRI,
2012):
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• All reclamation systems must undergo
commissioning tests that demonstrate
disinfection performance is consistent with
design intent.
• Velocity profiles have been eliminated as an
option for transferring pilot data to full-scale
facility design.
• On-site MS-2 based viral assays are used for
both the validation and commissioning test.
• A standard MS-2 dose-response curve is used
to derive the reduction equivalent dose.
• The design equation is based on the lower 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
Whitbyetal. (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 mg-
min/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 mg-
min/L have been reported to meet various reclaimed
water coliform standards (WRRF, 2012a).
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The addition of hydrogen peroxide (H2O2) to ozone in
wastewater has been shown to reduce bromate
formation (Ishida et. al., 2008) where this is a concern
due to the presence of bromide. Research reports
conflicting results, and the reasons for these
differences are not fully understood, although it is
known to be related to water chemistry. Further,
increasing the ozone contact time (while maintaining
ozone residual) from 30 seconds to 120 seconds does
not appear to substantially boost disinfection
performance (WRRF, 2012a).
Because of improvements in ozone generation and
dissolution technologies in recent years, which
improve the economics of the process along with
increasing interest in addressing CECs, several new
ozone systems for wastewater disinfection are under
design, under construction, and recently in operation.
In Anaheim, Calif., a 0.1 mgd (4.4 L/s) pressurized
ozone reactor (HiPOx by APTwater) will be in
operation by 2012 (Robinson, 2011). This system was
installed as part of a combined effort to produce high-
quality 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.
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Figure 6-3
Example WRF treatment train that includes UV/H2O2 AOP
6.4.3.5 Ferrate
Ferrate was explored in the 1970s as a replacement
chemical for chlorine, but prior synthesis methods
made its utilization cost prohibitive. With recent
advances in new on-site production methods of
ferrate, it has the potential to be applied as an
alternative to other widely-practiced oxidation and
disinfection processes. Research has demonstrated
that ferrate can be an extremely competitive oxidizing
agent for disinfection processes, with the key benefit of
minimizing by-product formation. Ferrate chemistry
results from formation of iron in the plus 6 oxidation
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 pilot-
scale 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 tofinishing water for
high-tech industries (Munter, 2001; WRRF, 20120-
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 (Miege et al., 2008).
Although a variety of base treatment technologies can
drive AOPs, each AOP is similar in that it is designed
to generate highly reactive, nonspecific intermediate
species (such as hydroxyl radicals and superoxide
radicals) (Glaze et al., 1987). There are several
technologies available for advanced oxidation that
show promise for reuse applications. AOPs are
designed to take advantage of the high
electrochemical oxidation potential of radical species,
combining parallel disinfection and oxidation
processes as shown in Table 6-8.
The hydroxyl radicals formed in an AOP work in
parallel to the primary disinfectant by breaking apart
organic compounds, resulting in the transformation of
toxic organic compounds into less-toxic daughter
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compounds (Stasinakis, 2008). Hydroxyl radical
formation and availability is affected by pH, but only at
pH extremes (Arakaki, 1999); at typical pH values,
hydroxyl radical formation rates will not vary
significantly (Watts et al., 1994). Free radicals quickly
react with electron acceptors in water, and as a result
wastewater has a high scavenging capacity (Rosario-
Ortiz 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
Hydroxyl Radical
Ozone
Peracetic Acid1
Hydrogen Peroxide
Hypochlorite
Chlorine
Chlorine Dioxide
EOP[V]
2.80
2.08
1.81
1.78
1.49
1.36
1.27
EOP Relative
to Chlorine
2.05
1.52
1.33
1.3
1.1
1
0.93
7 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. UV-
based 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 I PR
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 I PR is
the combined use of UV light and H2O2. In IPR
applications, UV/H2O2 not only provides disinfection,
but also destroys CECs (Drewes et al., 2002).
Examples include the OCWD and the WBMWD,
whose IPR projects provide groundwater
replenishment, and the community of Big Spring,
Texas, which has begun a project that will purify
wastewater to quality better than drinking water for the
augmentation of local surface water. In these cases,
an integrated membrane system (IMS) provides
significant pretreatment to the UV/H2O2 AOP.
The full-scale Advanced Water Purification Facility at
the OCWD's Groundwater Replenishment System,
commissioned in 2008, uses filtered secondary
wastewater effluent from a neighboring WWTP and
treats it to water that meets all drinking water quality
standards. The 70-mgd (3,100 L/s) system consists of
MF, RO, and UV/H2O2. The UV/H2O2 treatment step at
OCWD consists of a LPHO amalgam lamp UV system
comprised of multiple parallel trains of stacked UV
chambers (connected in series). To verify predicted
NDMA reductions, this UV/H2O2 system was tested to
demonstrate both NDMA destruction and
microorganism disinfection, showing that the system
was effective for both treatment objectives.
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6.4.5 Natural Systems
Natural filtration processes take advantage of intrinsic
characteristics of riverbanks, aquifers, and wetlands
comprised of media—soil and plants—that can filter
water and in some cases provide a surface for biofilm
growth that can biologically oxidize or reduce
contaminants. Two natural treatment approaches
include wetlands and soil aquifer filtration (which also
includes riverbank filtration for the purposes of this
discussion). The principles of how these natural
filtration processes can be used to confer additional
treatment are described in the EPA Process Design
Manual for Land Treatment of Municipal Wastewater
Effluents (EPA, 2006).
6.4.5.1 Treatment Mechanisms in Natural
Systems
Natural systems have the potential to reduce or
remove pathogens, organic carbon, contaminants of
concern, and nutrients during sub-surface transport.
As reclaimed water filters through the subsurface,
physical, biological, and chemical water quality
improvement occurs during SAT where spreading
basins are used (Section 2.3.3.2). During ASR, vadose
zone injection, or direct injection, these mechanisms
can also occur to a varying extent; this is especially
true of ASR systems, in which sub-surface residence
time can be highly variable.
Pathogens. Pathogens are a major concern in all
reclaimed water systems, and the highest risk
associated with pathogens is ingestion. Pathogen
removal efficacy for SAT systems via filtration and
disinfection is described in Demonstration of Filtration
and Disinfection Compliance through SAT (WRRF,
2012g). Pathogen removal during SAT is most efficient
during unsaturated flow but the unsaturated zone is
bypassed by direct injection into the aquifer during
ASR. For ASR, treatment efficiency determination is
site specific. Furthermore, pathogen removal during
ASR is less efficient when non-porous media is
present, for example, recharge into bedrock (e.g.
basalt) rather than into granular aquifers (sand).
Concerns over pathogens have resulted in the
implementation of travel time requirements for
environmental buffers in I PR 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 Id or greater when studying the
decay of E. coli in a sub-surface environment (Roslev
et al., 2004). Many of these studies were conducted
under controlled conditions in groundwater without the
effects of straining and sorption (filtration). Therefore,
decay alone may result in 5-log removal of E, coli in
less than 20 days during sub-surface transport.
However, E, coli decay rates do not inform pathogenic
human viral or parasitic protozoan decay rates.
Concern over viruses has prompted continued
research on virus transport and survival in
environmental buffers. Soil saturation and aquifer flow
type (porous or non-porous media), media
composition, ground water pH, and virus strain all
interact to affect the sorptive capacity and virus die-off
rate in soils and aquifers. Because viral subsurface
inactivation rates are an estimate, a second barrier
with reliable, effective disinfection is recommended.
Furthermore, virus removal by sorption is an active
research area and remains difficult to predict in field
studies. Similar concerns over protozoa have been
raised because Cryptosporidium oocysts and Giardia
cysts have been found in groundwater (Bridgman et al.
1995; Hancock et al. 1998) and in reclaimed water
(Gennancaro et al., 2003; Huffman et al., 2006)
including infectious Giardia. And, there have been
Cryptosporidium and Giardia outbreaks, some
associated with heavy rainfall (Bridgman et al. 1995;
Willocks et al. 1998; Rose et al. 2000; Curriero et al.
2001), with research revealing that Cryptosporidium
oocysts and Giardia cysts can be transported in the
subsurface under normal conditions, soil, especially
when preferential porous media flow paths exist
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(Darnault et al. 2003 and Park et al., 2012). Additional
research into the transport of protozoan pathogens is
needed.
Organic Carbon. Residual organic carbon is a
concern in I PR 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 |jg/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 (Rausch-
Williams 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 17p-Estradiol, tend to degrade on a time-
scale of days while more refractory compounds, such
as NDMA and sulfamethoxazole, tend to degrade over
a time-scale of weeks to months (Dickerson et al.,
2008). Persistent compounds, such as carbamezapine
and primodone, can persist for months or years in an
environmental buffer (Clara et al., 2004, Heberer,
2002). The transformation of organic constituents of
concern can depend on the presence of biodegradable
dissolved organic carbon (BDOC) because the
concentrations of constituents of concern are very low
and may not support growth (Rausch-Williams et al.,
2010; Nalinakumari et al., 2010).
Nitrogen. Reclaimed water that has not been nitrified
or denitrified may contain greater than 20 mg/L of
ammonia-nitrogen, which can exert over 100 mg/L of
nitrogenous oxygen demand. The majority of studies
on the fate of nitrogen have been done in the vadose
zone because wet/dry cycles can result in alternating
aerobic/anoxic conditions (Miller et al., 2006).
Alternating aerobic/anoxic conditions may facilitate
nitrogen cycling, and greater than 70 percent nitrogen
removal has been observed in the vadose zone at the
Tucson Sweetwater Underground Storage and
Recovery Facility. Other facilities have also sustained
nitrogen removal in the vadose zone when alternating
aerobic/anoxic conditions were maintained
(Kopchynski et al., 1996). This mechanism for removal
is not dependent on the retention time in the buffer
zone but is a function of recharge basin operation. The
aquifer below a vadose zone becomes anoxic when
ammonia is present in recycled water at levels
sufficient to deplete oxygen in percolating water
(AWWARF, 2001). Reduction of nitrate will occur as a
function of retention time under anoxic conditions as
nitrate is used as the electron acceptor for organic
compound transformations. If nitrate becomes
depleted, more reduced conditions can develop,
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
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 wastewater-
derived 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: 77 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 high-
quality 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 USAGE, the
BOR, and EPA's Environmental Technology Initiative.
The Tres Rios treatment wetlands are currently the
largest of their kind in Arizona. Highly-treated effluent
from the 91st Avenue WWTP was first delivered to a
98-ac cell in July 2010 with discharges regulated
under a NPDES permit overseen by EPA and an
Aquifer Protection Permit as mandated by the ADEQ.
The remaining two wetland cells are developing
mature wetland vegetation and were brought online
late in 2011. Treated water from the Tres Rios
wetlands is reused to support approximately 137 ac of
wetland and riparian habitat along the north bank of
the Salt River while at the same time conveying water
to satisfy contractual obligations to the Buckeye Water
Conservation District. This site, which serves as a
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
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 [US-
AZ-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 So/7 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.
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
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 energy-
intensive 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 large-
scale 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
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Chapter 6 | Treatment Technologies for Protecting Public and Environmental Health
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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Water Environment Research Foundation (WERF). 2008.
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Watts, R. J., S. Kong, M. Dippre, and W. T. Barnes. 1994.
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Whitby, G. E., O. Lawal, P. Ropic, S. Shmia, B. Ferran, and
B. Dussert. 2011. "Uniform Protocol for Wastewater UV
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Willocks, L, A. Crampin, L. Milne, C. Seng, M. Susman, R.
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Lightfoot. 1998. "A large outbreak of cryptosporidiosis
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borehole." Communicable Disease and Public Health.
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Drinking Water. WHO/HSE/WSH/11.05. Retrieved August
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Safe Use of Wastewater, Excreta and Greywater. Volume 2.
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Resistance. Retrieved August 23, 2012 from
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World Health Organization Scientific Group (WHO). 1989.
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Wu, C., A. L. Songberg, J. D. Witter, M. Fang, and K. P.
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Wunder, D. B., V. A. Horstman, and R. M. Hozalski. 2008.
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Yanko, W. A. 1999. "An Unexpected Temporal Pattern of
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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 full-
fledged 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 re-
investment.
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) (WEE, 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
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Chapter 7 | Funding Water Reuse Systems
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 large-
volume 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 well-
defined 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
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Chapter 7 | Funding Water Reuse Systems
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 Business-
Cooperative Service to help finance a water reuse
system that would support the creation of jobs in a
rural area.
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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 dual-
pipe 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
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Chapter 7 | Funding Water Reuse Systems
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 rationing-
resistant 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 water-
short 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
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Chapter 7 | Funding Water Reuse Systems
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 no-
interest 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 [US-
CA-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.
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Chapter 7 | Funding Water Reuse Systems
Table 7-1 Comparison of reclaimed water rates
First Tiers Only) Reclaimed Water Rates
Rate per Rate per % of Potable
Community 1,000 gal Use 1,000 gal Use Rate
Tucson, AZ
Dublin San Ramon
Services District, CA
Eastern Municipal
Water District, CA
Glendale Water and
Power, CA
Irvine Ranch Water
District, CA1
Los Angeles
Department of Water
and Power, CA
Boca Raton, FL
Cape Coral, FL
Orange County, FL
St. Petersburg, FL
City of Tampa, FL
Gary, NC
El Paso, TX
Hampton Roads
Sanitation District, VA
Loudoun Water,
Loudoun County, VA
San Antonio Water
System, San Antonio,
TX
$2.19
$7.82
$3.28
$3.48
$2.07
$3.79
$3.18
$1.62
$3.34
$5.78
$4.77
$0.742
$3.81
$1.04
$1.39
$3.45
$2.43
$2.82
$3.60
$5.79
$1.94
$4.00
$1.82
$1.09
$1.63
1 -15ccf
16-30ccf
Tier 1 Volume charge, first
22,440 gallons
Tier 2 Volume charge,
over 22,440 gallons
Tier 1 Indoor use
Tier 2 Outdoor use
Commercial Rate
Residential Detached
Base Rate 5-9 ccf
Residential Detached
Inefficient Rate 10-1 4 ccf
Residential Detached
Excessive Rate 15-1 9 ccf
Schedule C-First Tier
Jul-Sep High Season
0 - 25,000 gal
0 - 5,000 gal
0 - 3,000 gal
4,000 -10,000 gal
0 - 5,600 gal
0 - 5 ccf
6 -13 ccf
0 - 5,000 gal
0-15,000 gal
Over 4 ccf
Average rate for all uses
Variable, non-peak rate
Base volume charge at 90
% annual average use
Volume charge at 1 25 -
1 50% annual average use
$2.45
$3.19
$0.80
$0.88
$2.39
$1.44
$3.01
$5.20
1.42
1.76
$0.449
$0.0012
$9.50
$0.50
$0.74
$17.63
$10.10
$0.50
$1.60
$3.60
$1.24
$1.50
$1.28
$0.92
$0.99
Variable on all uses
Flat rate volume charge
R-452 Non-Ag, Secondary,
Disinfected-2009
R-462 Non-Ag, Tertiary, Disinfected,
Filtered-2009
Nonpotable purposes
Landscape Irrigation
Base Index 41-1 00% ET
Landscape Irrigation Inefficient Index
101-110%ET
Landscape Irrigation Excessive Index
111-1 20% ET
Valley and Metro
West Side and Harbor
0 - 25,000 gallons
Tiered rates per 1 ,000 gal
Res per lot sq. ft. multi-family
Fixed fee
Non-Res -per 1,000 gal.
Variable on > 4,000 gal/month
Unmetered - First acre
Unmetered > 1 acre
Metered"
Variable on all uses
Variable on all uses
Variable on all use
Variable on all uses
Variable, non-peak rate
Base Rate, first 748,000 gal
Seasonal Rate, first 748,000 gal
112%
31%
97%
92%
21% of Tier 2
23% of Tier 2
75%
89%
111%
111%
30%
37%
61%
13%
71%
53%
14%
66%
57%
100%
62%
64%
38%
70%
84%
61%
ccf =100 cubic feet
11rvine Ranch Water District employs a steep inclined rate based on watering in excess of the evapotranspiration (ET) rate.
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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
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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.
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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 ac-
ft. 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 Gary, 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 mid-
1960s 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
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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 single-
family homes in Florida
Number of
Percent Range Utilities
0%
1 % to 5%
6% to 1 0%
1 1 % to 20%
21% to 30%
31% to 40%
41% to 50%
51% to 60%
61 % to 70%
71% to 80%
81 % to 90%
91 % to 99%
1 00%
Total
Average percent
Median percent
Minimum percent
Maximum percent
39
0
8
10
10
7
7
4
2
1
1
0
5
94
22%
10%
0%
1 00%
Percent of
Utilities
41%
0%
9%
11%
11%
7%
7%
4%
2%
1%
1%
0%
5%
1 00%
(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
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Chapter 7 | Funding Water Reuse Systems
recovery for utilities is a large part of the socio-
economic 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 multi-
tiered, 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.
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Chapter 7 | Funding Water Reuse Systems
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 (Ml). 5th
edition. American Waterworks 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 Waterworks Association. Denver, CO.
American Water Works Association (AWWA). 2008. Water
Reuse Rates and Charges - Survey Results. American
Waterworks Association. Denver, CO.
Catalog of Federal Domestic Assistance (CFDA). n.d.
Catalog of Federal Domestic Assistance. Retrieved on
August 23, 2012 from .
Florida Department of Environmental Protection (FDEP).
2011 a. 2070 Reuse Inventory, Tallahassee, Florida.
Retrieved on August 23,2012 from
.
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
.
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. Lopez 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 05-007.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.
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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-CA-
Southern 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.).
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Chapters | Public Outreach, Participation, and Consultation
2004
12011
Strongly Favor Somewhat Somewhat Strongly
Favor Oppose Oppose
Unsure
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)
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 science-
based 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."
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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
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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 I PR, 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 cross-
section 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.
8-4
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• 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
(WERE) 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-VA-
Occoquan].
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 water-
related 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
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• 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 decision-
making 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?
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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.
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100
Before information
i After information
Don't mind at all
Mind a little
Mind a lot
Figure 8-2
Focus group participant responses: before and after viewing information (Source: Adapted From WRRF,
2011)
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
Fallen, 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 I PR 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).
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Without information
i With information
Waterthat Waterthat Verypure
is purer is a water
than standard
drinking higherthan
water drinking
water
Purified Reverse Repurified NEWater Recycled Reclaimed
recycled osmosis water water water
water water
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.)
Reuse Scenario Preference
SCENARI01: Business As Usual
SCENARIO 2: Blended Reservoir
SCENARIO 3: Upstream Discharge
SCENARIO 4: Direct Potable Use
Figure 8-4
Focus group participants preferred "direct potable use" over "business as usual," "blended reservoir," or
"upstream discharge" IPR options (WRRF 09-01)
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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,
201 Oa).
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-to-
understand 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, readily-
understandable 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, 201 Ob).
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
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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 disrupters 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.
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Figure 8-5
CVWD encourages its wholesale customers to
promote the notification of water reuse benefits
(Photo credit: Miguel Garcia)
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, 201 Ob).
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, 201 Oa). 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.
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Table 8-1 Focus group participant responses - most trusted sources (Source: Adapted from WRRF, 2012)
Source Number I Percentage Number I Percentage
Regulators
Consultants
University professors
Medical doctors
Local water agency spokesperson
130
27
42
56
47
43%
9%
14%
19%
16%
215
13
36
48
37
62%
4%
10%
14%
11%
Because trusted sources can vary from community to
community, state to state, and country to country—as
evidenced when comparing the WRRF (201Oa) 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.
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• 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 cost-
saving 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.
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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-to-
understand 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 in-
person 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 science-
based 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).
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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 e-
updates (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.
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• 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. Decision-
makers 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].
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).
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. I PR 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-CA-
San 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].
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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 Waterworks Association. Denver, CO.
CH2MHNI. 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
.
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 .
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
.
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, 201 2, from
.
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,
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). 201 Oa. The
Psychology of Water Reclamation and Reuse: Survey
Findings and Research Road Map. WRF-04-008.
WateReuse Foundation. Alexandria, VA.
WateReuse Research Foundation (WRRF). 201 Ob.
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. WRF-
07-03. 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.
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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 socio-
economic 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 low-
income or "developing" countries. Locations in middle-
income 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 Territories-
Auja] and [Philippines-Market]), as well as in resource-
endowed 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 [Spain-
Costa 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
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quality and related health risks. In resource-
constrained 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 disability-
adjusted life years (DALY) annually, or 0.017
DALY per person per year was estimated, which
represents nearly 10 percent of the WHO-
reported 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.
9-2
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Chapter 9 | Global Experiences in Water Reuse
ESI
CO 1.,
Cjp-1
INI
IN 3
•-1* TH.l*
Legervd
Caca JttudtoG by Cat*oofy ^ (3i Inchon* RBWB
0 ID LMMD RkuH O 14 EttwiDnrrVAri R«UM mr: <
A U'i AgnkiAifri l.finf + |S, putaLN RBUM
Figure 9-1
Geographic Display of International Water Reuse
Case Studies Categorized by Application
2012 Guidelines for Water Reuse
9-3
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Chapter 9 | Global Experiences in Water Reuse
Figure 9-1 Legend
Map code I Text code I Case Study Name
AR-1
AU-1
AU-2
AU-3
AU-4
BB-1
BE-1
BR-1
CA-1
CN-1
CO-1
CY-1
GH-1
IN-1
IN-2
IN-3
IL-1
IL-2
IL-3
IL-4
JP-1
JO-1
JO-2
MX-1
MX-2
MX-3
MX-4
PK-1
PS-1
PE-1
Argentina-Mendoza
Australia-Sydney
Australia-Graywater
Australia-Victoria
Australia-Replacement
Flows
Barbados-Economic
Analysis
Belgium-Recharge
Brazil-Car Wash
Canada-Nutrient
Transfer
China-MBR
Colombia-Bogota
Cyprus-Irrigation
Ghana-Agriculture
India-Delhi
India-Bangalore
India-Nagpur
Israel/Jordan-Brackish
Irrigation
Israel/Palestinian
Territories/Jordan-
Olive Irrigation
Israel/Jordan-AWT
Crop Irrigation
Israel/Peru-Vertical
Wetlands
Japan-Building MBR
Jordan-Irrigation
Jordan-Cultural
Factors
Mexico-Tijuana
Mexico-Mexico City
Mexico-Ensenada
Mexico-San Luis
Potosi
Pakistan-Faisalabad
Palestinian Territories-
Auja
Peru-Huasta
Special Restricted Crop Area in Mendoza, Argentina
Sewer Mining to Supplement Blackwater Flow in a Commercial High-rise
Retirement Community Graywater Reuse
End User Access to Recycled Water via Third Party-Owned Infrastructure
St Marys Advanced Water Recycling Plant, Sydney
Economic Analysis of Water Reuse Options in Sustainable Water Resource
Planning
Water Reclamation for Aquifer Recharge in the Flemish Dunes
Car Wash Water Reuse - A Brazilian Experience
Water Reuse Concept Analysis for the Diversion of Phosphorus from Lake Simcoe,
Ontario, Canada
Water Reuse in China
The Reuse Scenario in Bogota
Water Reuse In Cyprus
Implementing Non-conventional Options for Safe Water Reuse in Agriculture in
Resource Poor Environments
Reuse Applications for Treated Wastewater and Fecal Sludge in the Capital City of
Delhi, India
V Valley Integrated Water Resource Management: the Bangalore Experience of
Indirect Potable Reuse
City of Nagpur and MSPGCL Reuse Project
Managing Brackish Irrigation Water with High Concentrations of Salts in Arid
Regions
Irrigation of Olives with Recycled Water
Advanced Wastewater Treatment Technology and Reuse for Crop Irrigation
Treatment of Domestic Wastewater in a Compact Vertical Flow Constructed
Wetland and its Reuse in Irrigation
A Membrane Bioreactor (MBR) Used for Onsite Wastewater Reclamation and
Reuse in a Private Building in Japan
Water Reuse and Wastewater Management in Jordan
Cultural and Religious Factors Influence Water Reuse
Water, Wastewater, and Recycled Water Integrated Plan for Tijuana, Mexico
The Planned and Unplanned Reuse of Mexico City's Wastewater
Maneadero Aquifer, Ensenada, Baja California, Mexico
Tenorio Project: A Successful Story of Sustainable Development
Faisalabad, Pakistan: Balancing Risks and Benefits
Friends of the Earth Middle East's Community-led Water Reuse Projects in Auja
Assessing Water Reuse for Irrigation in Huasta, Peru
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Chapter 9 Global Experiences in Water Reuse
Figure 9-1 Legend
Map code
PH-1
SN-1
SG-1
ZA-1
ZA-2
ES-1
TH-1
TT-1
UK-1
AE-1
VN-1
Text code
Philippines-Market
Senegal-Dakar
Singapore-NEWater
South Africa-
eMalahleni Mine
South Africa-Durban
Spain-Costa Brava
Thailand-Pig Farm
Trinidad and Tobago-
Beetham
United Kingdom-
Langford
United Arab Emirates-
Abu Dhabi
Vietnam-Hanoi
Case Study Name
Wastewater Treatment and Reuse for Public Markets: A Case Study in Sustainable,
Appropriate Technology in the Philippines
Use of Wastewater in Urban Agriculture in Greater Dakar, Senegal: "Adapting the
2006 WHO Guidelines"
The Multi-barrier Safety Approach for Indirect Potable Use and Direct Nonpotable
Use of NEWATER
Turning Acid Mine Drainage Water into Drinking Water: The eMalahleni Water
Recycling Project
Durban Water Recycling Project
Risk Assessment for Legionella sp. in Reclaimed Water at Tossa de Mar, Costa
Brava, Spain
Sam Pran Pig Farm Company: Using Multiple Treatment Technologies to Treat Pig
Waste in an Urban Setting
Evaluating Reuse Options for a Reclaimed Water Program in Trinidad, West Indies
Langford Recycling Scheme
Water Reuse as Part of Holistic Water Management in the United Arab Emirates
Wastewater Reuse in Thanh Tri District, Hanoi Suburb, Vietnam
2012 Guidelines for Water Reuse
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Chapter 9 | Global Experiences in Water Reuse
Environmental Other 1.5%
enhancements 8.04%
Industrial 19.32%
Agricultural irrigation
32.01%
Water Reuse
by Application
Landscape irrigation
20.01%
Groundwater
recharge 2.1%
Recreational 6.39%
Non-potable urban
uses 8.25%
Indirect potable
reuse 2.3%
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)
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 Tobago-
Beetham], [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
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Chapter 9 Global Experiences in Water Reuse
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, boiler-
feed 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 I PR, 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 Volume
Total volume of domestic
wastewater generated as of
2009
Current global capacity to
treat wastewater to
advanced levels as of 2009
Total volume of domestic
wastewater that is not
treated to advanced levels
as of 2009
Growth in global capacity to
treat wastewater to
advanced levels (per year
since 2000)
180-250
8
172-242
0.5
680-960
32
648-928
2
Sources: GWI, 2010; FAO, 2010
There is limited reliable data documenting quantities of
water reuse and wastewater use in the agricultural
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Chapter 9 | Global Experiences in 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)
Additional advanced reuse
capacity (2009-2016)
Billion gallons Million
Country
per day
m /day
USA
China
Saudi Arabia
Australia
Spain
Mexico
United Arab Emirates
Oman
India
Algeria
2.8
1.6
0.9
0.7
0.6
0.6
0.5
0.4
0.3
0.3
10.7
5.9
3.5
2.5
2.1
2.1
1.9
1.6
1.2
1.1
DPR and planned I PR 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.
Source: GWI, 2010
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Chapter 9 Global Experiences in Water Reuse
•
Untreated & diluted
Treated
China 3 6 million ha outof
proportion: India > 1 million ha
« « 100 110 <» U9 W
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Chapter 9 | Global Experiences in 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.
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Chapter 9 Global Experiences in Water Reuse
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
Gyzen, 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 over-
ambitious policies that spur few sustainable, on-the-
ground 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)
Connected
Number of urban
countries with population
available data (%)
United States and
Canada
European Union
Australia
Central Asia
Middle East and North
Africa
Namibia, South Africa,
Zambia, Zimbabwe
Latin America and the
Caribbean
China
South Asia
Sub-Saharan Africa **
South-East Asia
2
18
1
5
7
4
21
1
6
24
5
94
90
87
83
83
68
64
56
31
9
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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Chapter 9 | Global Experiences in 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 disrupters, 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-CA-
San 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 up-
front 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
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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 resource-
endowed settings when water is reused in urban water
features and stream restoration projects. Other
benefits that are more likely to occur in resource-
endowed 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 resource-
constrained 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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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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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
con.ro, .easure '^^
A. Wastewater treatment
1-6
Notes
Pathogen reduction depends on type and degree of treatment
technology selected.
B. On-farm options
Alternative land and water source
Crop restriction (i.e., no food crops
eaten uncooked)
On-farm treatment:
(a) Three-tank system
(b) Simple sedimentation
(c) Simple filtration
Pathogen die-off (fecal sludge)
6-7
6-7
1-2
0.5-1
1-3
in line with WHO
2006
In Ghana, authorities supported urban farmers using
wastewater by drilling wells. In Benin, farmers were offered
alternative land with access to safer water sources.
Depends on (a) effectiveness of local enforcement of crop
restriction, and (b) comparative profit margin of the alternative
crop(s).
One pond is being filled by the farmer, one is settling and the
settled water from the third is being used for irrigation
Sedimentation for -18 hours.
Value depends on filtration system used
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
(b) Low-cost drip irrigation
(c) Reduction of splashing
Pathogen die-off (wastewater)
1-2
2-4
1-2
0.5-2
per day
Crop density and yield may be reduced.
2-log unit reduction for low-growing crops, and
4-log unit reduction for high-growing crops.
Farmers trained to reduce splashing when watering cans used
(splashing adds contaminated soil particles on to crop surfaces
which can be minimized).
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
Produce preparation prior to sale
0.5-1
1-2
2-3
1-3
Selling produce after overnight storage in baskets (rather than
overnight storage in sacks or selling fresh produce without
overnight storage).
(a) Washing salad crops, vegetables and fruit with clean water.
(b) Washing salad crops, vegetables and fruit with running tap
water.
(c) Removing the outer leaves on cabbages, lettuces, etc.
D. In-kitchen produce-preparation options
Produce disinfection
Produce peeling
Produce cooking
2-3
2
6-7
Washing salad crops, vegetables and fruit with an appropriate
disinfectant solution and rinsing with clean water.
Fruits, root crops.
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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Figure 9-4
Reducing the pathogenic health risks from unsafe use of diluted wastewater
(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)
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 [Australia-
Graywater]). 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 resource-
constrained 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).
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Wastewater
generation
Wastewater
treatment
Farmer/
Producer
i
Safe
irrigation
practices
-
i
i
1
•
1
•
1
1
•
1
•
1
Traders/
Retailers
i
j
Hygienic
handling
practices
Facilitating behaviour change vi;
market and non-market incentiv*
regular inspections
Street food
kitchens
i
Safe food
washing and
preparation
i education,
js, and
•J
-
Consumer
Awareness
creation
to create
demand for
safe produce
Figure 9-5
Multi-barrier approach to safeguard public health where wastewater treatment is limited (Amoah et al.,
2011)
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.
Guideline values are treated as absolute
values, and not as target values.
Treatment plants that do not comply with
global standards do not obtain licensing or
financing.
There is no affordable technology to lead to
compliance of standards.
Standards are not actually enforced.
Discharge standards are not compatible
with water quality standards.
Number of monitoring parameters are
frequently inadequate (too many or too
few).
There is no institutional development that
could support and regulate the
implementation of standards.
Reduction of health or environmental risks
due to compliance with standards is not
immediately perceived by decision makers
or the population.
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 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.
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.
Control technologies should be within the countries' financial conditions. The
use of appropriate technology should always be pursued.
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.
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.
The list of parameters should reflect the desired protection of the intended
water uses and local laboratory and financial capacities, without excesses or
limitations.
The efficient implementation of standards requires an adequate infrastructure
and institutional capacity to license, guide, and control polluting activities and to
enforce standards.
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.
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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 Gyzen, 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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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:
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
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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 price-
versus-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 best-
available 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 less-
participatory 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 long-
term 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 [India-
Nagpur].
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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Chapter 9 Global Experiences in Water Reuse
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 run-
to-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 [Singapore-
NEWater] and [India-Bangalore], irrigation [Spain-
Costa 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 multi-
purpose 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-for-
purpose" is illustrated dramatically in many of the
international reuse case studies ([Australia-
Replacement Flows], [Brazil-Car Wash], [Colombia-
Bogota], [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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Chapter 9 | Global Experiences in 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 resource-
constrained countries can move unplanned
wastewater use to planned reuse, while taking
advantage of modern treatment and non- or post-
treatment 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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Drechsel, P., and R. Seidu. 2011. "Cost-effectiveness of
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Huibers, F., M. Redwood, and L. Raschid-Sally. 2010.
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Risks In Low Income Countries. Earthscan. London, UK.
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Water Partnership (GWP). 2006. "Recycling realities:
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Policy Briefing, Issue 17. Battaramulla, Sri Lanka.
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"The Hyderabad Declaration on Wastewater Reuse in
Agriculture." Workshop on Wastewater Use in Irrigation
Agriculture: Confronting the Livelihood and Environmental
Realities, November 11-14, 2002, Hyderabad, India.
Jimenez, B., P. Drechsel, D. Kone, A. Bahri, L. Raschid-
Sally, and M. Qadir. 2010. "Wastewater, Sludge and Excreta
Use in Developing Countries: An Overview." In Drechsel, P.,
C.A. Scott, L. Raschid-Sally, M. Redwood and A. Bahri
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International Survey of Current Practice, Issues and Needs.
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Change to Reduce Pathogenic Risk Where Unsafe Water is
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Keraita, B., P. Drechsel, and F. Konradsen. 2008.
"Perceptions of Farmers on Health Risks and Risk Reduction
Measures in Wastewater-irrigation Urban Vegetable Farming
in Ghana." Journal of Risk Research. 11 (8):1047-1061.
Laugesen, C., O. Fryd, H. Brix, and T. Koottatep. 2010.
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Countries: New Paradigms and Case Studies from the Field.
ASCE Press. Reston, VA.
Macpherson, L. 2012. "Water: Nature's Amazing Reusable
Resource." In Water Sensitive Cities. IWA Publishing.
London, UK.
Mara, D., A. Hamilton, A. Sleigh, and N. Karavarsamis.
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Disease Improved Determination of Annual Risks Norovirus
and Ascaris Infection Risks. Extended Health-protection
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Mara, D. D. 2004. Domestic Wastewater Treatment in
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Murray, A., G. D. Mekala, and X. Chen. 2011. "Evolving
Policies and the Roles of Public and Private Stakeholders in
Wastewater and Faecal-sludge Management in India, China
and Ghana." Water International. 36(4):491-504.
Murray, A., and P. Drechsel. 2011. "Why Do Some
Wastewater Treatment Facilities Work When the Majority
Fail? Case Study From the Sanitation Sector in Ghana."
Waterlines. 30(2):135-149.
Murray, A., and C. Buckley. 2010. "Designing Reuse-
oriented Sanitation Infrastructure: The Design For Service
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Sally, M. Redwood and A. Bahri (eds.) Wastewater irrigation
and Health: Assessing and Mitigating Risks in Low-Income
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National Research Council (NRC). 2012. Water Reuse:
Potential for Expanding the Nation's Water Supply Through
Reuse of Municipal Wastewater. The National Academies
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in Zimbabwe in the Context of Sustainability." Water Policy.
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Scheierling, S. M., C. Bartone, D. D. Mara, and P. Drechsel.
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Emerging Priority." Policy Research Working Paper, 5412.
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M. Redwood, and B. Jimenez. 2010. "Wastewater Irrigation
and Health: Challenges and Outlook for Mitigating Risks in
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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.1.2USAID
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/Jordan-
AWT Crop Irrigation; Israel/Palestinian
Territories/Jordan-Olive Irrigation; Israel/Jordan-
Brackish 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,
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Appendix A | Funding for Water Reuse Research
however, presently closed to new applications. A CDR
case study from Israel and Peru is included [Case
study: Israel/Peru - Vertical Wetlands].
A.1.3USBR
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, co//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.1.4USDA
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. NIFA-
funded 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.
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Appendix A | Funding for Water Reuse Research
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.1.5USGS
USGS supports water reuse research through its
Water Census, aquifer storage and recovery (ASR)
program, and program on the occurrence of human-
use 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.1.6CDC
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.1.8NSF
NSF sponsors one fifth of the water resources
research in the United States (NRC, 2004), but does
2012 Guidelines for Water Reuse
A-3
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Appendix A | Funding for Water Reuse Research
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).
A-4
2012 Guidelines for Water Reuse
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Appendix A | Funding for Water Reuse Research
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
2012 Guidelines for Water Reuse
A-5
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Appendix A | Funding for Water Reuse Research
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.
.
U.S. Environmental Protection Agency (EPA). N.D. An
Introduction to the Water Elements of the EPA's Strategic
Plan. Retrieved July 31, 2012.
-------
APPENDIX B
Inventory of Recent Water Reuse Research
Projects and Reports
Project
Number Publication Date
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
2009
2009
2012 (pre-
publication)
2008
2008
2008
2011
2008
2008
2007
2009
2006
2004
2005
2003
2003
1996
2002 and 2006
1998
2004
1 Or anization
Sustainable Wastewater Management in Developing
Countries: New Paradigms and Case Stories from the
Field
Planning for the Distribution of Reclaimed Water
Assessment of Water Reuse as an Approach for
Meeting Future Supply Needs
Advanced Oxidation of Pharmaceuticals and Personal
Care Products: Preparing for Indirect and Direct Water
Reuse
Survey of High Recovery and Zero Liquid Discharge
Technologies for Water Utilities
Regional Solutions for Concentrate Management
The Impacts of Membrane Process Residuals on
Wastewater Treatment: Guidance Manual
Membrane Treatment of Impaired Irrigation Return and
Other Flows: Creating New Sources of High Quality
Water
Research Strategy for Water Reuse Workshop
Inland Membrane Concentrate Treatment Strategies for
Water Reclamation Systems
Design, Operation and Maintenance for Sustainable
Underground Storage Facilities
Comparing Nanofiltration and Reverse Osmosis for
Treating Recycled Water
Water Quality Changes During Aquifer Storage and
Recovery
Organic Nitrogen in Drinking Water and Reclaimed
Water
Industrial Water Quality Requirements for Reclaimed
Water
Water Quality Improvements During Aquifer Storage
and Recovery
ASR in Wisconsin Using the Cambrian-Ordovician
Aquifer
Comparison of Alternative Methods of Recharge of a
Deep Aquifer
Aquifer Storage and Recovery of Treated Drinking
Water
Investigation of Soil-Aquifer Treatment for Sustainable
Water Reuse
Issues with Potable Reuse: The Viability of Augmenting
Drinking Water Supplies with Reclaimed Water
Industrial Water Quality Requirements for Reclaimed
Water
American Society of
Civil Engineers
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA
AWWA Research
Foundation
2012 Guidelines for Water Reuse
B-1
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
Publication Date
2007
Removal of EDCs and Pharmaceuticals in Drinking and
Reuse Treatment Processes
Organization
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
B-2
2012 Guidelines for Water Reuse
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
-
-
92-WRE-1
92-HHE-1-CO
97-IRM-6
98-CTS-1
98-CTS-5
98-HHE-1
98-PUM-1CO
99-HHE-1
99-HHE-4ET
99-HHE-5-UR
99-PUM-4
99-WWF-6
OO-CTS-8
OO-CTS-11
00-CTS-14-ET
00-HHE-2A
00-HHE-2C
00-HHE-7-CO
00-HHE-2C
OO-PUM-1
OO-PUM-2T
OO-PUM-3
OO-WSM-6
Publication Date Title
2004
2008
-
-
-
-
-
-
-
-
-
-
-
-
Evaluation of Microbial Risk Assessment Techniques
and Applications
Using Reclaimed Water to Augment Potable Water
Resources
Water Reuse Assessment
Use of Reclaimed Water ad Sludge in Food Crop
Production
Non-Potable Water Reuse Management Practices
Research Needs to Optimize Wastewater Resource
Utilization
Feasibility and Application of Membrane Bioreactor
Technology for Water Reclamation
Cryptosporidium in Wastewater Occurrence, Removal
and Inactivation
A Comparative study of Physiochemical Properties and
Filtration of Several Human and Bacteria Viruses:
Implication for Groundwater Recharge
Effects of Wastewater Disinfection on Human Health
Handheld Advanced Nucleic Acid Analyzer (HANNA)
forWaterborne Pathogen Detection
Development of Molecular Methods for Detection of
Infectious Viruses in Treated Wastewater
Impact of Surface Storage on Reclaimed Water:
Seasonal and Long Term
Online Monitoring of Water Effluent Chlorination Using
ORP vs. Residual Chlorine Measurement
Membrane Technology: Feasibility of Solid/Liquid
Separation in Wastewater Treatment
Membrane Technology: Pilot Studies of Membrane-
Aerated Bioreactors
A Novel Membrane Process for Autotrophic
Denitrification
Overcoming Molecular Sample Processing Limitations:
New Platform Technologies
Overcoming Molecular Sample Processing Limitations:
Quantitative PCR
Endocrine Disrupters and Pharmaceutically Active
Chemicals in Drinking Water
Overcoming Molecular Sample Processing Limitations:
FiberOptic Biosensors
Water Reuse: Understanding Public Perception and
Participation
Reduction of Pathogens, Indicator Bacteria, and
Alternative Indicators by Wastewater Treatment and
Reclamation Processes
Evaluation of Microbial Risk Assessment Techniques
and Applications
Strategies for Sustainable Water Resource
Management
Organization
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
Water Environment
Research Foundation
2012 Guidelines for Water Reuse
B-3
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
00-WSM-6A
Publication Date
Moving Towards Sustainable Water Resources
Management: A Framework and Guidelines for
Implementation
Water Environment
Research Foundation
01-CTS-6and
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-18CO
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-1CO
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
B-4
2012 Guidelines for Water Reuse
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
-
-
-
-
-
-
WRF-01-001
WRF-01-002
WRF-01-004
WRF-01-005
WRF-01-006
WRF-01-007
WRF-01-008
WRF-02-001
WRF-02-002
WRF-02-003
WRF-02-004
WRF-02-006a
WRF-02-006b
WRF-02-006C
WRF-02-006d
WRF-02-007
WRF-02-008
WRF-02-009
WRF-02-011
WRF-03-001
WRF-03-005
WRF-03-006-01
Publication Date Title
2004
2008
2011
2010
2011
2010
Dec-05
May-06
Jun-05
May-06
May-06
2006
2007
May-06
Jun-06
Aug-11
Nov-08
Aug-08
Sep-06
Jul-08
Aug-08
2003
Mar-09
Aug-12
2005
2007
Sep-06
2004
Best Practices for Developing Indirect Potable Reuse
Projects: Phase 1 Report
The Impacts of Membrane Process Residuals on
Wastewater Treatment Guidance Manual
Optimization of Advanced Oxidation Processes for
Water Reuse : Effect of Effluent Organic Matter on
Organic Contaminant Removal
Low-Cost Treatment Technologies for Small-Scale
Water Reclamation Plants
Direct Potable Reuse : A Path Forward
Oxidative Treatment of Organics in Membrane
Concentrates
Alternative Methods for the Analysis of NDMA and
Other Nitrosamines in Water and Wastewater
Removal and/or Destruction of NDMA in Wastewater
Treatment Processes
Best Practices for Developing Indirect Potable Reuse
Projects: Phase 1 Report
Characterizing and Managing Salinity Loadings in
Reclaimed Water Systems (AWWARF 91009)
Characterizing Microbial Water Quality in Reclaimed
Water Distribution Systems (AWWARF 91072F)
Removal of Endocrine Disrupting Compounds in Water
Reclamation Processes (WERF 01HHE20T)
Innovative DMA Array Technology for Detection of
Pharmaceutics in Reclaimed Water (WERF
01HHE21T)
Rejection of Wastewater- Derived Micropollutants in
High-Pressure Membrane Applications
Investigation of NDMA Fate and Transport
Filter Loading Evaluation for Water Reuse
National Database on Water Reuse Facilities -
Summary Report
Survey of High Recovery and Zero Liquid Discharge
Technologies for Water Utilities
Beneficial and Non-Traditional Uses of Concentrate
The Impacts of Membrane Process Residuals on
Wastewater Treatment
Regional Solutions for Concentrate Management
Using Surfactants in Optimizing Water Usage on Turf
Grasses
A Reconnaissance-Level Quantitative Comparison of
Reclaimed Water, Surface Water, and Groundwater
Study of Innovative Treatment on Reclaimed Water
Framework for Developing Water Reuse Criteria with
Reference to Drinking Water Supplies (UKWIR
05/WR/29/1)
Pathogen Removal and Inactivation in Reclamation
Plants - Study Design
Marketing Nonpotable Recycled Water: A Guidebook
for Successful Public Outreach & Customer Marketing
Water Reuse Economic Framework Workshop Report
Organization
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
2012 Guidelines for Water Reuse
B-5
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Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
WRF-03-006-02
WRF-03-009
WRF-03-010
WRF-03-011
WRF-03-012
WRF-03-013
WRF-03-014
WRF-04-001
WRF-04-002
WRF-04-003
WRF-04-004
WRF-04-005
WRF-04-006
WRF-04-007
WRF-04-008
WRF-04-009
WRF-04-010
WRF-04-011
WRF-04-012
WRF-04-013
WRF-04-014
WRF-04-016
WRF-04-017
WRF-04-018
WRF-04-019
Publication Date Title
Sep-06
Aug-07
2004
2004
Aug-08
2008
Dec-08
2008
May-06
2008
Jan-09
Mar-12
2005
2005
Dec-09
Aug-12
Nov-07
Nov-07
Aug-09
Aug-10
Apr-09
Jun-09
Mar-10
2009
Apr-09
An Economic Framework for Evaluating Benefits and
Costs of Water Reuse
Reclaimed Water Aquifer Storage and Recovery:
Potential Changes in Water Quality
Water Reuse Foundation's Water Reuse Research
Needs Workshop
Research Needs Assessment Workshop on Integrating
Human Reactions to Water Reclamation into Reuse
Project Design
Salt Management Guide
Rejection of Contaminants of Concern by NF and
ULPRO Membranes for Treating Water of Impaired
Quality
Development of Indicators and Surrogates of Chemical
Contaminants and Organic Removal in Wastewater
and Water Reuse
Prospects for Managed Underground Storage of
Recoverable Water
Effects of Recycled Water on Turfgrass Quality
Maintained Under Golf Course Fairway Conditions
Toxicological Relevance of Endocrine Disruptors &
Pharmaceuticals in Drinking Water (AWWARF 91238)
Honolulu Membrane Bioreactor Pilot Study
Use of Recycled Water for Community Gardens
Irrigation of Parks, Playgrounds, and Schoolyards with
Reclaimed Water: Extent and Safety
GWRC Water Reuse Research Strategy
The Psychology of Water Reclamation and Reuse:
Survey Findings and Research Roadmap
Reclaimed Water Inspection and Cross Connection
Control Guidebook
Extending the IRP Process to Include Water Reuse and
Other Non-Traditional Water Sources
Application of Microbial Risk Assessment Techniques
to Estimate Risk Due to Exposure to Reclaimed Waters
Exploring, Interpreting, and Presenting Microbial Data
Associated with Reclaimed Water Systems: A
Guidance Manual
Improved Sample Collection and Concentration Method
for Multiple Pathogen Detection
Decision Support System for Selection of Satellite vs.
Regional Treatment for Reuse
A Protocol for Estimating Potential Water Quality
Impacts of Recycled Water Projects
Reaction Rates and Mechanisms of Advanced
Oxidation Processes (AOP) for Water Reuse
Contributions of Household Chemicals to Sewage and
Relevance to Municipal Wastewater Systems and the
Environment (WERF 03CTS21 UR)
Methods for the Detection of Residual Concentrations
of Hydrogen Peroxide in Advanced Oxidation
Processes
Organization
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
B-6
2012 Guidelines for Water Reuse
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
WRF-04-021
WRF-05-001
WRF-05-002
WRF-05-004
WRF-05-005
WRF-05-006
WRF-05-007
WRF-05-008
WRF-05-009
WRF-05-010
WRF-05-011
WRF-06-001
WRF-06-002
WRF-06-003
WRF-06-004
WRF-06-005
WRF-06-006
WRF-06-007
WRF-06-008
WRF-06-009
WRF-06-010a
WRF-06-010b
WRF-06-010d
WRF-06-010e
Publication Date Title
Dec-09
Nov-09
Jan-10
Nov-11
Aug-10
Jan-11
Jun-09
Sep-09
Aug-07
May-1 0
Aug-09
Nov-08
Jan-09
Expected Oct-1 2
Aug-12
Dec-09
Expected Mar-1 3
Mar-12
Jul-10
Expected Jan-13
Expected Oct-1 2
Expected Sep-12
Expected Dec-12
Expected Jan-13
Selecting Treatment Trains for Seasonal Storage of
Reclaimed Water
Evaluating Pricing Levels and Structures to Support
Reclaimed Water Systems
Microbiological Quality/Biostability of Reclaimed Water
Following Storage and Distribution
Development of Surrogates to Determine the Efficacy
of Soil Aquifer Treatment Systems for the Removal of
Organic Chemicals
Identification of PPCPs for Screening Based on
Persistence through Treatments used for Indirect
Potable Reuse and Toxicity
Evaluate Wetland Systems for Treated Wastewater
Performance to Meet Competing Effluent Quality Goals
Selection and Testing of Tracers for Measuring Travel
Times in Groundwater Aquifers Augmented with
Reclaimed Water
The Effect of Salinity on the Removal of Contaminants
of Concern during Biological Water Reclamation
Dewatering Reverse Osmosis Concentrate from Water
Reuse Applications Using Forward Osmosis
Oxidative Destruction of Organics in Membrane
Concentrates
Formation and Fate of Chlorination Byproducts in
Desalination Systems
Conduct Survey Research to Obtain Information/Data
from all Water Recycling Facilities in CA
Developing a Pragmatic Research Agenda for
Examining the Value of Water Supply Reliability
The Occurrence of Infectious Cryptosporidium Oocysts
in Raw, Treated and Disinfected Wastewater
Identifying Health Effects Concerns of the Water Reuse
Industry and Prioritizing Research Needs for
Nomination of Chemicals for Research
Leaching of Metals from Aquifer Soils during Infiltration
of Low-Ionic-Strength Reclaimed Water: Determination
of Kinetics and Potential Mitigation Strategies
Comparisons of Chemical Composition of Recycled
and Conventional Waters
Investigation of Membrane Bioreactor Effluent Water
Quality and Technology
Low-Cost Treatment Technologies for Small-Scale
Water Reclamation Plants
Predictive Models to Aid in Design of Membrane
Systems for Organic Micropollutants Removal
State of the Science Review of Membrane Fouling:
Organic, Inorganic, and Biological
Feasibility Study of Offshore Desalination Plants
Consideration for the Co-Siting of Desalination
Facilities with Municipal and Industrial Facilities
Development of Selective Recovery Methods for
Desalination Concentrate Salts
Organization
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
2012 Guidelines for Water Reuse
B-7
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
WRF-06-010f
WRF-06-010g
WRF-06-011
WRF-06-012
WRF-06-013
WRF-06-014
WRF-06-015
WRF-06-016
WRF-06-017
WRF-06-018
WRF-06-018
WRF-06-018
WRF-06-019
WRF-06-020
WRF-06-021
WRF-07-01
WRF-07-02
WRF-07-03
WRF-07-04
WRF-07-05
WRF-07-06
WRF-08-01
WRF-08-02
WRF-08-04
Publication Date
2010
2011
Expected Jan-13
May-1 1
Expected Oct-1 2
Dec-11
Dec-10
Jul-11
May-1 2
Apr- 11
Nov-10
Expected Oct-1 2
May-1 0
Sep-11
Jun-12
Expected Nov-1 2
Expected Oct-1 2
Jul-11
Expected Oct-1 2
Expected Oct-1 2
Expected Oct-1 2
Nov-10
Dec-12
Expected Jan-13
Organization
Post Treatment Stabilization of Desalinated Water
(WaterRF 4079)
Assessing Seawater Intake Systems for Desalination
Plants (WaterRF 4080)
Enhanced Disinfection of Adenoviruses with UV
Irradiation
Optimization of Advanced Oxidation Processes (AOP)
for Water Reuse
Investigating the Feasibility of MBR to Achieve Low
Nitrogen Levels for Water Reuse
Characterization of US Seawaters & Development of
Standardized Protocols for Evaluation of Foulants in
Seawater RO Desalination
Sequential UV and Chlorination for Reclaimed Water
Disinfection
Guidance on Links between Water Reclamation and
Reuse and Regional Growth
Water Reuse in 2030: Identifying Future Challenges
and Opportunities
Development and Application of Tools to Assess and
Understand the Relative Risks of Regulated Chemicals
in Indirect Potable Reuse Projects - Tasks 1-3
Tool to Assess and Understand the Relative Risks of
drugs and Other Chemicals in Indirect Potable Reuse
Water: Development and Application
Tool to Assess and Understand the Relative Risks of
drugs and Other Chemicals in Indirect Potable Reuse
Water: Executive Summary
Monitoring for Microcontaminants in an Advanced
Wastewater Treatment Facility and Modeling Discharge
of Reclaimed Water to Surface Canals for Indirect
Potable Use
Attenuation of Emerging Contaminants in Streams
Augmented with Recycled Water
Interagency Partnerships to Facilitate Water Reuse
Validation of Microbiological Methods for Use with
Reclaimed Waters
Development of a Knowledge Base on Concentrate
and Salt Management Practices
Talking About Water: Vocabulary and Images that
Support Informed Decisions about Water Recycling and
Desalination
Evaluation of Impact of Nanoparticle Pollutants
Membrane Distillation using Nanostructured
Membranes
Recycled Water Use in Zoo/Wildlife Facility Settings
Assessment of Approaches to Achieve Nationally
Consistent Reclaimed Water Standards
Attenuation of PPCP/EDCs through Golf Courses using
Reuse Water (WERF1 COS)
Approaches to Maintain Consistently High Quality
Reclaimed Water in Storage and Distribution Systems
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
2012 Guidelines for Water Reuse
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
WRF-08-05
WRF-08-06
WRF-08-07
WRF-08-08
WRF-08-09
WRF-08-10
WRF-08-11
WRF-08-12
WRF-08-13
WRF-08-14
WRF-08-15
WRF-08-16
WRF-08-17
WRF-08-18
WRF-08-19
WRF-09-01
WRF-09-02
WRF-09-03
WRF-09-04
WRF-09-05
WRF-09-06a
WRF-09-06b
WRF-09-07
WRF-09-07
WRF-09-08
WRF-09-09
WRF-09-10
WRF-09-11
Publication Date Title
Expected Feb-13
Expected Jan-13
Expected Nov-1 2
Expected Apr-1 3
Expected Oct-1 2
Dec-11
Expected Jul-13
Expected Dec-12
Expected Oct-1 2
Expected Oct-1 2
Expected Sep-12
Aug-12
Feb-12
Mar-12
Expected Mar-1 3
Expected Dec-12
Expected Jun-13
Expected Apr-1 3
Expected Apr-1 3
Expected Sept-12
Expected Mar-1 3
Expected Mar-1 3
May-1 2
Expected Oct-1 2
Expected Feb-13
Expected Sep-12
Feb-13
Expected Feb-14
Use of Ozone in Water Reclamation for Contaminant
Oxidation
Evaluation of Alternatives to Domestic Ion Exchange
Water Softeners
Disinfection Guidelines for Satellite Water Recycling
Facilities
Pilot-Scale Oxidative Technologies for Reducing
Fouling Potential in Membrane Systems
Value of Water Supply Reliability in Residential Sector
Maximizing Recovery of Recycled Water for
Groundwater Recharge
Process Optimization, Monitoring and Control
Strategies, and Carbon and Energy Footprint UV/H2O2
Assess water use requirements and establish water
quality criteria
Renewable energy, peak power management, and
optimization of advanced treatment technologies
Evaluation and optimization of existing and emerging
energy recovery devices
Evaluating Emergency Planning under Climate Change
Scenarios
Implications of Future Water Supply Sources on Energy
Demands
Reclaimed Water Desalination Technologies:
Performance/Cost Comparison EDR & MF/RO
Infectivity Assay for Giardia lamblia Cysts
Investigation of Desalination Membrane Biofouling
The Effect of Prior Knowledge of 'Unplanned' Potable
Reuse on Acceptance of 'Planned' Potable Reuse
Develop a Framework to Determine When to Use
Indirect Potable Reuse Systems vs. Dual Pipe
Utilization of HACCP Approach for Evaluating Integrity
of Treatment Barriers for Reuse
The Value of Water Supply Reliability in the CM Sector
Case Studies of Seasonal Storage of Reclaimed Water
for Discharge into Surface Waters
Develop New Techniques for Real-Time Monitoring of
Membrane Integrity
Develop New Techniques for Real-Time Monitoring of
Membrane Integrity
Risk Assessment Study of PPCPs in Recycled Water to
Support Public Review - Toolkit
Risk Assessment Study of PPCPs in Recycled Water to
Support Public Review - Main Report
Evaluation of Potential Nutrient Impacts Related to
Florida's Water Reuse Program
Pilot Testing Pre-Formed Chloramines as a Means of
Controlling Biofouling in Seawater Desalination
Use of UV & Fluorescence Spectra as Surrogate
Measures for Contaminant Oxidation and Disinfection
in Ozone/Peroxide Advanced Oxidation Processes
Development of New Tracers for Determining Travel
Time Near MAR Operations
Organization
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
2012 Guidelines for Water Reuse
B-9
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
WRF-09-12
WateReuse-10-
01
WateReuse-10-
02
WateReuse-10-
03
WateReuse-10-
04
WateReuse-10-
05
WateReuse-10-
06a
WateReuse-10-
06b
WateReuse-10-
06c
WateReuse-10-
06d
WateReuselO-
06 II
WateReuse-10-
07
WateReuse-10-
08
WateReuse-10-
09
WateReuse-10-
10
WateReuse-10-
11
WateReuse-10-
12
WateReuse-10-
13
WateReuse-10-
14
WateReuse-10-
15
WateReuse-10-
16
WateReuse-10-
17
WateReuse-10-
18
WateReuse-11-
01
WateReuse-11-
02
Publication Date Title
Expected Nov-1 2
Expected May-14
Expected Mar-1 3
Expected Jun-13
Expected Jul- 2013
Expected Nov-1 4
Aug-13
Expected Aug-13
Expected May-13
Expected Aug-13
TBD
Expected May-14
Expected Feb-13
Expected Apr-1 3
Expected Nov-1 2
Expected Jul-13
Expected May-1 3
Expected Nov-1 2
Expected Nov-1 2
Expected Oct-1 3
Expected Oct-1 3
Expected Jul-13
Expected Dec-13
Expected Mar-1 6
Expected Jul-15
Continuous Flow Seawater RO System for Recovery of
Silica Saturated RO Concentrate
Fit for Purpose Water: The Cost of "Over- Treating"
Reclaimed and other Water
Treatment, Public Health, and Regulatory Issues
Associated with Graywater Reuse
Regulatory Workshop on Critical Issues of Desalination
Permitting
Improvements to Minimize I&E of Existing Intakes
Role of Retention Time in the Environmental Buffer of
Indirect Potable Reuse Projects
Lower Energy Treatment Schemes for Water Reuse,
Part A
Lower Energy Treatment Schemes for Water Reuse,
Part B
Lower Energy Treatment Schemes for Water Reuse,
Part C
Lower Energy Treatment Schemes for Water Reuse,
Part D
Lower Energy Treatment Schemes for Water Reuse -
Phase II
Bio-analytical Techniques to Assess the Potential
Human Health Impacts of Reclaimed Water
Guidance for Implementing Reuse in New Buildings &
Developments to Achieve LEED/Sustainability Goals
Guidance for Selection of Salt, Metal, Radionuclide,
and other Valuable Metal Recovery Strategies
Demonstration of Filtration and Disinfection
Compliance through SAT
Ozone Pretreatment of Non-Nitrified Secondary
Effluent before Microfiltration
Feasibility Study on Model Development to
Estimate/Minimize GHG Concentrations and Carbon
Footprint of WateReuse and Desalination Facilities
Review of Nano-Material Research and Relevance for
Water Reuse
Future of Purple Pipes: Exploring best use of non-
potable recycled water in diversified urban water
systems
Establishing Nitrification Reliability Guidelines for Water
Reuse
Enzymes: The New Wastewater Treatment Chemical
for Water Reuse
Understanding the Influence of Stakeholder Groups on
the Effectiveness of Urban Recycled Water Program
Implementation
Regulated and Emerging Disinfection by-Products
during the Production of High Quality Recycled Water
Monitoring for Reliability and Process Control of
Potable Reuse Applications
Equivalency of Advanced Treatment Trains for Potable
Reuse
Organization
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
B-10
2012 Guidelines for Water Reuse
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
Project
Number
WateReuse-11-
03
WateReuse-11-
04
WateReuse-11-
05
WateReuse-11-
06
WateReuse-11-
07
WateReuse-11-
08
WateReuse-11-
09
WateReuse-11-
10
WateReuse-12-
01
WateReuse-12-
02
WateReuse-12-
03
WateReuse-12-
05
WateReuse-12-
06
WateReuse-12-
07
WateReuse-12-
08
WateReuse-12-
10
Publication Date Title
Expected Sep-14
Expected Mar-15
Expected May-14
Expected Oct-1 3
Expected Jan-15
Expected Oct-1 4
Expected Jan-14
Expected Dec-13
TBD
TBD
TBD
TBD
TBD
TBD
TBD
Expected Sept-1 3
Develop Best Management Practices to Control
Potential Health Risks and Aesthetic Issues Associated
with Storage/Distribution of Reclaimed Water
Emerging Desalination Technologies for Energy
Reduction
Demonstrating the Benefits of Engineered Direct
versus Unintended Indirect Potable Reuse Systems
Real Time Monitoring for Microbiological Contaminants
in Reclaimed Water: State of the Science Assessment
Application of the Bioluminescent Saltwater Assimilable
Organic Carbon Test as a Tool for Identifying and
Reducing Reverse-Osmosis Membrane Fouling in
Desalination
Formation of Nitrosamines and Perfluorochemicals
during Ozonation in Water Reuse Applications
Desalination Concentrate Management Policy Analysis
for the Arid West
Evaluation of Risk Reduction Principles for Direct
Potable Reuse
Desalination Facility Guidelines (Scoping Study)
Development of Public Communication Toolbox for
Desalination Projects
Analysis of Technical and Organizational Issues in the
Development and Implementation of Industrial Reuse
Projects
Management of Legionella in Water Reclamation
Systems
Guidelines for Engineered Storage Systems
Standard Methods for Integrity Testing of NF and RO
Membranes
Public Acceptance Clearinghouse of Information for
Website
Demonstrating an Innovative Combination of Ion
Exchange Pretreatment and Electrodialysis Reversal
for Reclaimed Water RQ Concentrate Minimization
Organization
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
WateReuse Foundation
2012 Guidelines for Water Reuse
B-11
-------
Appendix B | Inventory of Recent Water Reuse Research Projects and Reports
This page intentionally left blank.
B-12 2012 Guidelines for Water Reuse
-------
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/aovernment-affairs/usepa-auidelines.
State
Alabama
Alaska
Alaska -
additional
Arizona
Arkansas
California
California -
additional
Colorado
Colorado -
additional
Commonwealth
of the Northern
Mariana Islands
Connecticut
Delaware
additional
Title of Regulations or Guidelines
Guidelines and Minimum Requirement
for Municipal, Semi-Public and Private
Land Treatment Facilities
Alaska Administrative Code, Title 18 -
Environmental Conservation, Chapter
Arizona Administrative Code - Title 18,
Environmental Quality
40 CFR 257, 40 CFR 503, and
guidance from NRCS (for animal
wastes)
Title 22 California Code of Regulations
Water Quality Control Commission:
Regulation No. 84 - Reclaimed Water
Control Regulation (effective 9/30/07)
Commonwealth of the Northern
Mariana Islands Wastewater
Treatment and Disposal Rules and
Regulations
No regulations or guidelines at this
time
Link to State Reuse Regulations Alternate Link to Reuse
or Guidance Fact Sheet or Report
http://adem.alabama.qov/alEnviroRe
gLaws/default.cnt
http://dec.alaska.gov/commish/regul
ations/pdfs/18%20AAC%2072.pdf
http://dec.alaska.gov/water/wwdp/in
dex.htm
http://www.azsos.gov/public service
s/Title 18/18 table.htm
http://www.adeq.state.ar.us/water/re
gulations.htm
http://www.cdph.ca.gov/certlic/drinki
ngwater/Pages/Lawbook.aspx
http://www.cdph.ca.goV/Healthlnfo/e
nvironhealth/water/Pages/Waterrecy
http://www.cdphe.state.co.us/regulat
ions/wqccregs/
http://www.cdphe.state.co.us/regulat
ions/wqccregs/100284wqccreclaime
dwater.pdf
http://www.deq.gov.mp/artdoc/Sec6
art32ID130.pdf
http://www.ct.gov/dep/cwp/view.asp
?a=2709&q=324216&depNav GID=
1643
http://www.dnrec.delaware.gov/wr/ln
formation/regulations/Pages/Ground
WaterDischargesRegulations.aspx
http://www.dnrec.state.de.us/water2
000/Sections/GroundWat/Library/Re
claimedWaterFactSheet.pdf
^^^H
http://www.azdeq.gov/en
viron/water/permits/reclai
med.html
http://www.waterboards.c
a.gov/water issues/progr
ams/grants loans/water
recvcling/directorv.shtml
2012 Guidelines for Water Reuse
C-1
-------
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse
District of
Columbia
Florida
Georgia
Georgia -
additional
Guam
Hawaii
Hawaii -
additional
Idaho
Idaho -
additional
Illinois
Indiana
Iowa
Kansas
Title of Regulations or Guidelines
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.
Chapter 62-61 0 of the Florida
Administrative Code "Reuse of
Reclaimed Water and Land
Application; Section 403.064 of the
Florida Statutes
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)
Guidelines for the Treatment and Use
of Recycled Water
Idaho Administrative Code, Tittle 01,
Chapter 17, IDAPA58.01.17 -
Recycled Water Rules
Title 35 Illinois Administrative Code
Part 372 - Illinois Design Standards for
Slow Rate Land Application of Treated
Wastewater
Article 6.1 "Land application of
Biosolid, Industrial Waste Product, and
Pollutant-bearing Water" of Title 327
Water Pollution Control Board, Indiana
Administrative Code.
Iowa Administrative Code Chapter 62:
Effluent and Pretreament Standards:
Other Effluent Limits or Prohibitinos
Link to State Reuse Regulations
http://www.dep.state.fl.us/water/reus
e/apprules.htm
http://www.qaepd.orq/Files PDF/tec
hquide/wpb/reuse.pdf
http://www.qaepd.org/Documents/te
chquide wpb.html
http://epa.guam.gov/rules-
reqs/requlations/water-pollution-
requlation:
http://hawaii.gov/wastewater/pdf/reu
se-final.pdf
http://hawaii.gov/dlnr/cwrm/planning
augmentation.htm
http://adminrules.idaho.gov/rules/cur
rent/58/01 17.pdf
http://adminrules.idaho.gov/rules/cur
rent/58/index.html
http://www.ipcb.state.il.us/document
s/dsweb/Get/Document-1 2046/
http://www.in.gov/idem/4877.htm
http://www.iowadnr.gov/lnsideDNR/
RegulatorvWater/NPDESWastewate
rPermitting/NPDESRules.aspx
http://www.kdheks.gov/water/downlo
ad/28 16.pdf
Alternate Link to Reuse
Fact Sheet or Report
http://www.ilga.gov/legisl
ation/ilcs/fulltext.asp?Doc
Name=007023050K7
http://www.in.gov/legislati
ve/iac/title327.html
http://www.iowadnr.goV/p
ortals/idnr/uploads/water/
wastewater/dstandards/c
hapter21 .pdf?amp;tabid=
1316
http://www.kwo.org/Kans
as Water Plan/KWP Do
CS/VOIUmelll/LAKi\/Kpt L
ARK BPI Role Reuse
KWP2009.pdf
C-2
2012 Guidelines for Water Reuse
-------
Appendix C Websites of U.S. State Regulations and Guidance on Water Reuse
•
Kentucky
Louisiana
Maine
Maryland
Maryland -
additional
Massachusetts
Massachusetts -
additional
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nebraska -
additional
Nebraska -
additional
Nebraska -
additional
Title of Regulations or Guidelines
No regulations or guidelines at this
time
No regulations or guidelines at this
time
No regulations or guidelines at this
time
Environment Article, Title 9, Subtitle 3;
UUIVIAK ^b.uo.u i tnrougn ^0.00.04
and 26.08.07.
Title 11 9, Chapter 12 - Land
Application of Domestic Effluent, Land
Application of Single Pass Noncontact
uooiing water and Disposal or
Domestic Biosolids
Link to State Reuse Regulations
or Guidance
Web Address could not be located
at time of publication.
Web Address could not be located
at time of publication.
Web Address could not be located
at time of publication.
http ://www. mde .state . md . us/assets/
rlnn impnt/MRF \A/MA
001%20%28land-
treatment%20Guidelines%29.pdf
http://www.mde.state.md.us/prodra
ms/Permits/WaterManadementPerm
Jts/WaterDischardePermitApplication
s/Pades/Permits/WaterManadement
Permits/water permits/index.aspx
http://www.mass.dov/dep/service/re
dulations/31 4cmr20.pdf
http://www.mass.dov/dep/service/re
gulations/31 4cmr05.pdf
Web Address could not be located
at time of publication.
http://www.pca.state.mn.us/index.ph
D/view-document.html?did=1 3496
http://www.deq.state.ms.us/newweb/
MDEQRedulations.nsf?OpenDataba
se
http://www.sos. mo. dov/adrules/csr/c
urrent/1 Ocsr/1 Ocsr.asp#1 0-20
http://deq.mt. dov/wqinfo/pws/docs/d
ed2 revisions.pdf
http://www.deq.state.ne.us/RuleAnd
Rn<;f/nanpc;/1 1 Q Ph 19
http://www.deq.state.ne.us/RuleAnd
R.nsf/23e5e39594c064ee852564ae
004fa01 0/97c32c5cd6c1 802d86256
74b006da528?OpenDocument
http://www.deq.state.ne.us/RuleAnd
R.nsf/23e5e39594c064ee852564ae
004fa01 0/235cf1 39930e82d086256
74b006e0738?OpenDocument
http://www.deq.state.ne.us/RuleAnd
R.nsf/23e5e39594c064ee852564ae
004fa01 0/6fc9b4ab05f90c8e862567
4b006fa9ab?OpenDocument
Alternate Link to Reuse
Fact Sheet or Report
^^^^B
http://www.mde.state.md.
us/prodrams/Permits/Wat
erManadementPermits/D
ocuments/www. mde.stat
e.md. us/assets/document
/permit/ MU t-wiviA-
PER014.pdf
http://www.mass.dov/dep
/water/wastewater/wrfaqs
.htm#permit
http://www.dnr.mo.dov/en
v/wpp/permits/index.html
http://www.deq. state. ne.u
s/RuleandR.nsf/Pades/R
ules
2012 Guidelines for Water Reuse
C-3
-------
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse
State Title of Regulations or Guidelines or Guidance Fact Sheet or Report
Nevada
Nevada -
additional
New Hampshire
New Jersey
New Mexico
New Mexico -
additional
New York
North Carolina
North Dakota
Ohio
Ohio - additional
Oklahoma
Oklahoma -
additional
Oregon
Nevada Administrative Code, Chapter
445A, Sections 274 - 280; WTS-1A
General design criteria for reclaimed
water irrigation use; WTS-1 B 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
No regulations or guidelines at this
time
NMED Ground Water Quality Bureau
Guidance: Above Ground Use of
Reclaimed Domestic Wastewater
15A North Carolina Administrative
Pnrlp Si ihrhantpr 09! I Rprlaimprl
Water
Criteria for Irrigation with Treated
Wastewater; Recommended Criteria
for Land Disposal of Effluent
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.
Oregon Administrative Rules, Division
http://www.leg.state.nv.us/nac/nac-
445a.html#NAC445ASec275
http://ndep.nv.gov/admin/nrs.htm
http://des.nh.gov/organization/comm
issioner/legal/rules/index.htm#water
http://www.state.nj.us/dep/dwq/714a
.htm
http://www.nmenv.state.nm.us/gwb/
documents/NMED REUSE 1-24-
07.pdf
http://www.nmenv.state.nm.us/gwb/
NMED-GWQB-Regulations.htm
Web Address could not be located
at time of publication.
http://reports.oah.state.nc.us/ncac. a
sp?folderName-\Title%201 5A%20-
%20Environment%20and%20Natura
l%20Resources\Chapter%2002%20-
%20Environmental%20Management
http://www.ndhealth.gov/WQ/
http://www.epa. state. oh. us/portals/3
http://www.epa.state.oh.us/dsw/pti/in
dex.aspx
http://www.deq.state.ok.us/rules/656
.pdf
http://www.deq.state.ok.us/rules/627
.pdf
http://arcweb.sos.state.or.us/pages/r
ules/oars 300/oar 340/340 055. ht
ml
httpV/ndep.nv.gov/bwpc/f
actOI .htm
http://www.state.nj.us/de
p/dwq/techmans/reusem
an. pdf
http://www.rmwea.org/reu
se/NewMexico.html
http://reports.oah.state.nc
.us/ncac/title%201 5a%20
%20environment%20and
%20natural%20resource
s/chapter%2002%20-
%20environmental%20m
anagement/subchapter%
20u/subchapter%20u%2
Orules.html
http://www.epa. state. oh. u
s/portals/35/rules/42-
13 factsheet feb08.pdf
http://normantranscript.co
m/x1552633625/Citv-of-
Norman-considers-using-
reclaimed-water-for-
purposes
http://www.deq. state. or. u
s/wq/reuse/reuse . htm
C-4
2012 Guidelines for Water Reuse
-------
Appendix C Websites of U.S. State Regulations and Guidance on Water Reuse
Pennsylvania
Puerto Rico
Rhode Island
South Carolina
South Dakota
South Dakota -
additional
Tennessee
Tennessee -
additional
Texas
US Virgin
Islands
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Title of Regulations or Guidelines
Manual for Land Treatment of
Wastewater; Reuse of Treated
Wastewater Guidance Manual
Section 67.300 of South Carolina
Regulation 61-67, Standards for
Wastewater Facility Construction
"State Land Application Permit"
Reuse requirements moved to UCA
R31 7-3-11 (from UCA R31 7-1 -2).
Environmental Protection Rules,
Chapter 14, Indirect Discharge Rules
Virginia Administrative Code Agency
and Reuse Regulation
Chapter 90.46 Revised Code of
Washington - Reclaimed water use
Title 64 Series 47 Chapter 16-1
Sewage Treatment and Collection
System Design Standards
Domestic Wastewater to Subsurface
Soil Absorption Systems Permit (Wl-
OOR9Q01 91
Chapter 21 Water Quality Rules -
Standards for the Reuse of Treated
Wastewater
Link to State Reuse Regulations
or Guidance
http://www.elibrary.dep.state.pa.us/d
sweb/Get/Document-88575/385-
91 RR 009 nrlf
Web Address could not be located
at time of publication.
http://www.dem.ri.qov/proqrams/ben
viron/water/permits/wtf/pdfs/reuseqy
d.pdf
http://www.scdhec.gov/environment/
water/landpage.htm
http://www.denr.sd.qov/des/sw/docu
ments/DesiqnCriteriaManual.pdf.
http://leqis.state.sd.us/statutes/Displ
avStatute.aspx?Tvpe=StatuteChapt
er&Statute=34A-2
www.tn.gov/environment/permits/wq
http://denr.sd.gov/des/sw/eforms/DO
449V1-a potw appl.pdf
http://www.tceq.texas.gov/rules/indx
pdf.html#210
Web Address could not be located
at time of publication.
http://www.rules.utah.gov/publicat/co
rle/r^l 7/r?1 7 001 htm*T4
http://www.anr.state.vt.us/dec/ww/rul
es.htm#os
http://lis.virginia.gov/000/reg/TOC09
Q25.HTM#C0740
http://apps.leg.wa.gov/rcw/default.as
http://apps.sos.wv.gov/adlaw/csr/rul
eview.aspx?document=2802
http://dnr.wi.gov/org/water/wm/ww/st
atauth.htm
http://soswv.state.wv.us/Rules/RUL
ES/2804.pdf
Alternate Link to Reuse
Fact Sheet or Report
http://www.elibrary.dep.st
ate.pa.us/dsweb/View/Co
llection-10105
www.tn.gov/environment/
wpc/publications/#tech
http://www.rules.utah.gov
/publicat/code/r317/r317-
003.htm#T11
http://www.anr.state.vt.us
/dec/ww/Rules/l PR/Adopt
ed-IDR-4-30-03.pdf
http://www.ecy.wa.gov/pr
ograms/wq/reclaim/index.
html
http://deq.state.wv.us/wq
d/WQDrules/index.asp
2012 Guidelines for Water Reuse
C-5
-------
Appendix C | Websites of U.S. State Regulations and Guidance on Water Reuse
This page intentionally left blank.
C-6 2012 Guidelines for Water Reuse
-------
APPENDIX D
U.S. Case Studies
List of Case Studies by Title and Authors1
Page No.
D-5
D-7
D-10
D-12
D-14
D-18
D-20
D-22
D-24
D-27
D-30
D-33
D-35
D-38
D-40
Text code
US-AZ-Gilbert
US-AZ-Tucson
US-AZ-Sierra Vista
US-AZ-Phoenix
US-AZ-Blue Ribbon
Panel
US-AZ-Prescott
Valley
US-AZ-Frito Lay
US-CA-Psychology
US-CA-San Ramon
US-CA-San Diego
US-CA-Orange
County
US-CA-North City
US-CA-Santa Cruz
US-CA-Monterey
US-CA-Southern
California MWD
Case Study Title 1 Authors
Town of Gilbert Experiences Growing Pains
in Expanding the Reclaimed Water System
Tucson Water: Developing a Reclaimed
Water Site Inspection Program
Environmental Operations Park
91st Avenue Unified WWTP Targets 100
Percent Reuse
Arizona Blue Ribbon Panel on Water
Sustainability
Effluent Auction in Prescott Valley, Arizona
Frito-Lay Process Water Recovery
Treatment Plant, Casa Grande, Arizona
The Psychology of Water Reclamation and
Reuse Survey: Findings and Research
Roadmap
Managing a Recycled Water System
through a Joint Powers Authority: San
Ramon Valley
City of San Diego - Water Purification
Demonstration Project
Groundwater Replenishment System,
Orange County, California
EDR at North City Water Reclamation Plant
Water Reuse Study at the University of
California Santa Cruz Campus
Long-term Effects of the Use of Recycled
Water on Soil Salinity Levels in Monterey
County
Metropolitan Water District of Southern
California's Local Resource Program
Guy Carpenter, P.E. (Carollo Engineers)
Karen Dotson (Retired, Tucson Water)
Kerri Jean Ormerod (University of
Arizona)
Steve Rohrer, P.E. and Tim Francis,
P.E., BCEE (Malcolm Pirnie, the Water
Division of ARCADIS); Andrew Brown,
P.E. (City of Phoenix)
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)
Christopher Scott, PhD (University of
Arizona)
Al Goodman, P.E. (COM Smith)
Brent M. Haddad, MBA, PhD (University
of California, Santa Cruz)
David A. Requa, P.E. (Dublin San
Ramon Services District)
Marsi A. Steirer; Amy Dorman, P.E.;
Anthony Van; and Joseph Quicho
(City of San Diego Public Utilities
Department)
Mike Markus, P.E., D.WRE; Mehul
Patel, P.E.; William Dunivin (Orange
County Water District)
Eugene Reahl and Patrick Girvin (GE)
Tracy A. Clinton, P.E. (Carollo
Engineers)
B.E. Platts (Monterey Regional Water
Pollution Control Agency)
Raymond Jay (Metropolitan Water
District)
1 To search for case studies by region or by category of reuse, please refer to Figure 5-2.
2012 Guidelines for Water Reuse
D-1
-------
Appendix D | U.S. Case Studies
List of Case Studies by Title and Authors1
Page No.
D-42
D-46
D-48
D-51
D-53
D-55
D-57
D-61
D-63
D-65
D-68
D-70
D-73
D-76
D-77
D-80
D-83
D-85
D-87
D-90
D-93
Text code
US-CA-Los Angeles
County
US-CA-Elsinore
Valley
US-CA-Temecula
US-CA-Santa Ana
River
US-CA-Vander Lans
US-CA-
Pasteurization
US-CA-Regulations
US-CA-West Basin
US-CO-DenverZoo
US-CO-Denver
US-CO-Denver
Energy
US-CO-Denver Soil
US-CO-Sand Creek
US-CO-Water
Rights
US-DC-Sidwell
Friends
US-FL-Miami So
District Plant
US-FL-Pompano
Beach
US-FL-Orlando E.
Regional
US-FL-Economic
Feasibility
US-FL-Reedy Creek
US-FL-Marco Island
Case Study Title
Montebello Forebay Groundwater Recharge
Project using Reclaimed Water, Los Angeles
County, California
Recycled Water Supplements Lake Elsinore
Replacing Potable Water with Recycled
Water for Sustainable Agricultural Use
Water Reuse in the Santa Ana River
Watershed
Leo J. Vander Lans Water Treatment
Facility
Use of Pasteurization for Pathogen
Inactivation for Ventura Water, California
California State Regulations
West Basin Municipal Water District: Five
Designer Waters
Denver Zoo
Denver Water
Xcel Energy's Cherokee Station
Effects of Recycled Water on Soil Chemistry
Sand Creek Reuse Facility Reuse Master
Plan
Water Reuse Barriers in Colorado
Smart Water Management at Sidwell
Friends School
South District Water Reclamation Plant
City of Pompano Beach OASIS
Eastern Regional Reclaimed Water
Distribution System
Economic Feasibility of Reclaimed Water to
Users
Reuse at Reedy Creek Improvement District
Marco Island, Florida, Wastewater
Treatment Plant
Authors
Monica Gasca, P.E. and Earle Hartling
(Los Angeles County Sanitation
Districts)
Ronald E. Young, P.E., DEE (Elsinore
Valley Municipal Water District)
Graham Juby, PhD, P.E. (Carollo
Engineers)
Celeste Cantu (Santa Ana Watershed
Project Authority)
R. Bruce Chalmers, P.E. (COM Smith)
and Paul Fu, P.E. (Water
Replenishment District)
Andrew Salveson, P.E. (Carollo
Engineers)
James Crook, PhD, P.E., BCEE (Water
Reuse Consultant)
Shivaji Deshmukh, P.E. (West Basin
Municipal Water District)
Abigail Holmquist, P.E. (Honeywell);
Damian Higham (Denver Water); and
Steve Salg (Denver Zoo)
Abigail Holmquist, P.E. (Honeywell);
Mary Stahl, P.E. (Olsson Associates);
and Steve Price, P.E. (Denver Water)
Abigail Holmquist, P.E. (Honeywell) and
Damian Higham (Denver Water)
Abigail Holmquist, P.E. (Honeywell) and
Damian Higham (Denver Water)
Bobby Anastasov, MBA and Richard
Leger, CWP (City of Aurora)
Cody Charnas (COM Smith)
Laura Hansplant, RLA, ASLA, LEED AP
(Andropogon Associates [formerly]
and Roofmeadow) and Danielle
Pieranunzi, LEED AP BD+C
(Sustainable Sites Initiative)
R. Bruce Chalmers, P.E. (COM Smith)
and James Ferguson (Miami Dade
Water and Sewer Department)
A. Randolph Brown and Maria Loucraft
(City of Pompano Beach)
Victor J. Godlewski Jr. (City of Orlando);
Greg D. Taylor, P.E. and Karen K.
McCullen, P.E., BCEE (COM Smith)
Grace M. Johns, PhD (Hazen and
Sawyer) and C. Donald Rome, Jr.
(Southwest Florida Water Management
District)
Ted McKim, P.E., BCEE (Reedy Creek
Improvement District)
Jennifer Watt, P.E. (General Electric);
Solomon Abel, P.E. (COM Smith); and
Rony Joel, P.E., DEE (AEC Water)
D-2
2012 Guidelines for Water Reuse
-------
Appendix D U.S. Case Studies
List of Case Studies by Title and Authors1
Page No.
D-96
D-98
D-99
D-102
D-104
D-107
D-110
D-113
D-115
D-118
D-121
D-123
D-124
D-126
D-129
D-132
D-134
D-136
D-139
D-141
Text code
US-FL-Everglade
City
US-FL-Orlando
Wetlands
US-FL-SWFWMD
Partnership
US-FL-Altamonte
Springs
US-FL-Clearwater
US-FL-Turkey Point
US-GA-Clayton
County
US-GA-Forsyth
County
US-GA-Coca Cola
US-HI-Reuse
US-MA-
Southborough
US-MA-Hopkinton
US-MA-Gillette
Stadium
US-ME-Snow
US-MN-Mankato
US-NC-Cary
US-NY-PepsiCo
US-PA-Kutztown
US-PA-Mill Run
US-TN-Franklin
Case Study Title Authors
Everglade City, Florida
City of Orlando Manmade Wetlands System
Regional Reclaimed Water Partnership
Initiative of the Southwest Florida Water
Management District
The City of Altamonte Springs: Quantifying
the Benefits of Water Reuse
Evolution of the City of Clearwater's
Integrated Water Management Strategy
Assessing Contaminants of Emerging
Concern (CECs) in Cooling Tower Drift
Sustainable Water Reclamation Using
Constructed Wetlands: The Clayton County
Water Authority Success Story
On the Front Lines of a Water War,
Reclaimed Water Plays a Big Role in
Forsyth County, Georgia
Recovery and Reuse of Beverage Process
Water
Reclaimed Water Use in Hawaii
Sustainability and LEED Certification as
Drivers for Reuse: Toilet Flushing at The
Fay School
Decentralized Wastewater Treatment and
Reclamation for an Industrial Facility, EMC
Corporation Inc., Hopkinton, Massachusetts
Sustainability and Potable Water Savings as
Drivers for Reuse: Toilet Flushing at Gillette
Stadium
Snowmaking with Reclaimed Water
Reclaimed Water for Peaking Power Plant:
Mankato, Minnesota
Town of Gary, North Carolina, Reclaimed
Water System
Identifying Water Streams for Reuse in
Beverage Facilities: PepsiCo ReCon Tool
The Water Purification Eco-Center
Zero-Discharge, Reuse, and Irrigation at
Fallingwater, Western Pennsylvania
Conservancy
Franklin, Tennessee Integrated Water
Resources Plan
Rony Joel, P.E., DEE (AEC Water)
Mark Sees (City of Orlando)
Alison Ramoy (Southwest Florida Water
Management District)
David Ammerman, P.E. (AECOM)
Laura Davis Cameron, BSBM; Tracy
Mercer, MBA;
Nan Bennett, P.E.; and Rob Fahey, P.E.
(City of Clearwater Public Utilities)
James P. Laurenson (HEAC) and
Edward L. Carr (ICF International)
Veronica Jarrin, P.E. and Jim Bays,
P.W.S (CH2M HILL); Jim Poff (Clayton
County Water Authority)
Daniel E. Johnson, P.E. (COM Smith)
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)
Elson C. Gushiken (ITC Water
Management, Inc.)
Mark Elbag (Town of Holden)
Mike Wilson, P.E. (CH2M Hill)
Mike Wilson, P.E. (CH2M Hill)
Don Vandertulip, P.E., BCEE (COM
Smith)
Mary Fralish (City of Mankato) and Patti
Craddock (Short Elliott Hendrickson
Inc.)
Leila R. Goodwin, P.E. (Town of Gary)
and Kevin Irby, P.E. (COM Smith)
Liese Dallbauman, PhD (Pepsi-Co
Global Operations)
Jeff Moyer and Christine Ziegler Ulsh
(Rodale Institute)
Mike Wilson, P.E. (CH2M Hill)
Jamie R. Lefkowitz, P.E. and Kati Bell,
PhD, P.E. (COM Smith); and Mark Hilty,
P.E. (City of Franklin)
2012 Guidelines for Water Reuse
D-3
-------
Appendix D | U.S. Case Studies
List of Case Studies by Title and Authors1
Page No.
D-145
D-148
D-150
D-152
D-154
D-157
D-160
D-163
D-166
D-169
D-172
Text code
US-TX-San Antonio
US-TX-Big Spring
US-TX-Landscape
Study
US-TX-NASA
US-TX-Wetlands
US-VA-Occoquan
US-VA-Regulation
US-WA-Sequim
US-WA-Regulations
US-WA-King County
US-WA-Yelm
Case Study Title | Authors
San Antonio Water System Water Recycling
Program
Raw Water Production Facility: Big Spring
Plant
Site Suitability for Landscape Use of
Reclaimed Water in the Southwest
U.S. Water Recovery System on the
International Space Station
East Fork Raw Water Supply Project: A
Natural Treatment System Success Story
Potable Water Reuse in the Occoquan
Watershed
Water Reuse Policy and Regulation in
Virginia
City of Sequim's Expanded Water
Reclamation Facility and Upland Reuse
System
Washington State Regulations
Demonstrating the Safety of Reclaimed
Water for Garden Vegetables
City of Yelm, Washington
Pablo R. Martinez (San Antonio Water
System)
David W. Sloan, P.E., BCEE (Freese
and Nichols)
Seiichi Miyamoto, PhD and Ignacio
Martinez (Texas A&M Agrilife Research
Center at El Paso)
J. Torin McCoy (NASA Johnson Space
Center)
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)
Robert W. Angelotti (Upper Occoquan
Service Authority) and Thomas J.
Grizzard, PhD, P.E. (Virginia Tech)
Valerie Rourke, CPSS, LPSS, CNMP
(Virginia Department of Environmental
Quality)
Chad Newton, P.E. (Gray & Osborne,
Inc.)
Chad Newton, P.E. (Gray and Osborne,
Inc.) and Craig Riley, P.E. (Washington
State Department of Health)
Sally Brown, PhD (University of
Washington)
Shelly Badger (City of Yelm)
D-4
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) 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.
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.
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.
2012 Guidelines for Water Reuse
D-5
-------
Appendix D | U.S. Case Studies
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).
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)
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.
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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 non-
potable 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 ac-
ft/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) 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:
1. Secondary effluent from Pima County's Roger
Road WWTP that receives additional filtration and
disinfection at Tucson Water's Filtration Plant
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 Us), and the summer peak delivery is
approximately 31 mgd (1358 Us).
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-by-
step 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
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Appendix D | U.S. Case Studies
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 one-
time $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
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Appendix D | U.S. Case Studies
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
.
City of Tucson. 2010. Mayor and Council Ordinance:
Requiring Inspections. Available from
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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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Appendix D | U.S. Case Studies
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.
2012 Guidelines for Water Reuse
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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 ac-
ft/yr (83.5 MCM/yr) is delivered to a nuclear, power-
generating 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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Appendix D | U.S. Case Studies
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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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 (USDA-Agricultural Research Service, U.S. Arid Land Agricultural
Research Center); and Sharon Megdal, PhD (University of Arizona)
US-AZ-Blue Ribbon Panel
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:
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.
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 time-
consuming 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).
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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 ill, 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
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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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Appendix D | U.S. Case Studies
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
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Frito-Lay Process Water Recovery Treatment Plant, Casa
Grande, Arizona
Author: Al Goodman, P.E. (COM 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 Frito-
Lay to reduce its water use by 100 million gallons
(380,000 m3) annually. An aerial view of the PWRTP is
shown in Figure 1.
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.
Figure 1
Aerial View of PWRTP (Photo credit: Frito-Lay)
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 in-
plant 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.
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D-20
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Appendix D | U.S. Case Studies
Figure 2
Water at Various Stages of the Treatment Process
(Photo credit: Frito-Lay)
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
i
'
RECOVERED -REUSE
FINISHED
WM ER TANK
PUMPING
EQUALIZATION
STABILIZATION
ADDED
SUPPLEMENTAL
WATER (FOR REJECT
REPLACEMENT]
REJECT
'TOPOTW
SOLIDS, SUCH AS
POTATO PEELINGS
AND CORN KERNELS,
ARE GIVEN TO LOCAL
FARMERS AS
ANIMAL FEED.
Figure 3
PWRTP process flow diagram
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.
2012 Guidelines for Water Reuse
D-21
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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 water-
related 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 water-
related)
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
2012 Guidelines for Water Reuse
D-22
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Appendix D | U.S. Case Studies
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 decision-
making 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.
2012 Guidelines for Water Reuse
D-23
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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.
San Ramon Valley
Recycled Water Program
Pipeline Map
March 2011
SRVRWP Transmission Pipeline
Dublin San Ramon Services District
Recycled Water Pipeline
Future Dublin San Ramon Services
District Recycled Water Pipeline
Ea« lay Municipal Utility District
Recycled Water Pipeline
Future East Bay Munnipal Utility
District Recycled Water Pipeline
Dublin San Ramon Services District
Water Service Area
East Bay Municipal Utility District
Water Service Area
•fr Pumping Station
© Future Pumping Station
O RMetvcXr
:'-. Water Recycling Plant
Figure 1
San Ramon Valley reclaimed water system (March 2010)
2012 Guidelines for Water Reuse
D-24
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Appendix D | U.S. Case Studies
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 low-
interest 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, 2011 a).
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).
2012 Guidelines for Water Reuse
D-25
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Appendix D | U.S. Case Studies
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. 2011 a. 2010 Urban
Water Management Plan. Dublin, California.
Dublin San Ramon Services District. 2011b.
Budget, Fiscal Year 2011-2012. Dublin, California.
DERWA
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.
2012 Guidelines for Water Reuse
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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 non-
potable 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.
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
City of San Diego's
Demonstration Project
Water Purification Demonstration Process
Phase 2 Demonstration-Scale Project
North City Water
Reclamation Plant
Advanced Water
Purification Facility
I rrm
ninrTTTirrmrrm
Tertiary
Cfttuent
Wasttwottr
Traditional Reclaimed
WotfiUitf
• irrigation
• manufacturing
• Membrane Filtration
• RevtneOunoin
• Disinfection IUV& Peroxide)
Water Sources
San Vicente Reservoir
local Runoff
Imported Walei
• Colorado River
• BayOttto
Potable
Water
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Illl
• Detention
• Natural Treatment
Potable Water Treatment Plant
• Coagulation
• Filtration
• Diiinftction (Ozone & Chlorine)
Raw Source Water
Phase 3
Full-Scale Advanced Water Purification
Plant 4 Transmission Pipeline
Figure 1
Water Purification Demonstration Process
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 full-
scale 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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
• 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.
.
City of San Diego Public Utilities Department - Water
Purification Demonstration Project website. 2011.
.
San Diego Water Authority (SDCWA). 2011. Public Opinion
Research. Retrieved on Sept. 7, 2012 from
.
2012 Guidelines for Water Reuse
D-29
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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 (WF-
21), 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)
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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 non-
detectable 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 non-
detectable 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.
\
Figure 3
GWRS ultraviolet reactor system (Photo
Credit: Gina DePinto)
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
^^_^^^^^__ f°r 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, drought-
proof 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.
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
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 Us).
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
2012 Guidelines for Water Reuse
D-31
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Appendix D | U.S. Case Studies
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 "toilet-
to-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,
Said 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 city-
state 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.
2012 Guidelines for Water Reuse
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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 Us). 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.
Figure 1
North City WRP with 6th EDR unit installed
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.
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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.
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Performance of North City EDR system
2012 Guidelines for Water Reuse
D-34
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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 non-
potable water are aligned.
Table 1 Summary of non-potable water demands
Demand
Toilet Flushing
Irrigation
Cooling Towers
Volume
Required
(MGY)
6.3
291
82
Seasonal
Dependence
Dependent on student
populations
Dependent on weather
Dependent on student
populations and
weather
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
RBr
Rainwater
Graywater
Recycled
Well
8.3
13.8
1571
56.5
Seasonal
Dependence
Dependent on weather
Dependent on student
populations
Dependent on student
populations
Not seasonally
dependent
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
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 non-
potable 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.
SUPPLIES
fa Recycled Water
4 Rainwater
-------
Appendix D | U.S. Case Studies
Table 3 Requirements for reuse depending on source water
possibleReuse calions
Rainwater
Graywater1
Additionally Treated
Graywater
Tertiary Treated/Disinfected
Wastewater3
Well Water
Irrigation, Toilet Flushing, HVAC
processes
Subsurface Irrigation
Irrigation, Toilet Flushing, HVAC
processes
Irrigation, Toilet Flushing, HVAC
processes
Irrigation, Toilet Flushing, HVAC
processes
Appendix G
Graywater
Guidelines
X
Title 22 Reuse
Guidelines
X
X
Campus
Plumbing Codes
and Ordinances
X
X
X
X
X
Treated and applied as outlined in the California Greywater Reuse Guidelines - Appendix G, Title 24, Part 5, California
Administrative Code.
Treated to greater levels than outlined in the California Greywater Reuse Guidelines
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 long-
term 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
2. Porter College Toilet
Flushing
3. Biomedical Sciences
Facility Toilet Flushing
4. Jordan Gulch Middle
Fork Cooling Towers
5. Irrigation
6. Family Student Housing
Landscape Irrigation
Rainwater
Rainwater
Rainwater
Rainwater
Recycled
Water
Graywater
Irrigation
Toilet
Flushing
Toilet
Flushing
Cooling
Towers
Irrigation
Irrigation
References
Maddaus Water Management and UC Santa Cruz. 2007. UC
Santa Cruz Water Efficiency Survey, Draft Report.
2012 Guidelines for Water Reuse
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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
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Appendix D | U.S. Case Studies
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
.
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.
2012 Guidelines for Water Reuse
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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 acre-
feet (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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D-40
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Appendix D | U.S. Case Studies
ultimate yield of about 323,000 ac-ft/yr (398 MCM/yr)
when fully implemented.
. . M Metropolitan Water District
of Southern California
Figure 1
Local Resource Program Recycled Water Projects
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.
2012 Guidelines for Water Reuse
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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,
MMJOMCMCCK
Will-WIST
LINlDCMAHNtL
= CMAMNCL LINIO *IO». OPCN BOTTOM
: : : UN UNI o CHANNEL
WRP DISCHARGE LINES
Figure 1
Montebello Forebay Groundwater Recharge Sites
2012 Guidelines for Water Reuse
D-42
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Appendix D | U.S. Case Studies
sequential chlorination was implemented, minimizing
production of trihalomethanes and N-
nitrosodimethylamine. 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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Appendix D | U.S. Case Studies
Table 1 Average recycled water quality and California drinking water limits October 2010-September 2011
Constituent
Organics
1,1-Dichloroethane
1,1-Dichloroethene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
1 ,1 ,2,2-Tetrachloroethane
1,2-Dichloroethane
1 ,2-Dichloropropane
1 ,2,4-Trichlorobenzene
2,4-D
2,4,5-TP (silvex)
Atrazine
Benzene
bis(2-Ethylhexyl) phthalate
Carbon tetrachloride
Chlorobenzene
cis-1,2-Dichloroethene
Endrin
Ethylbenzene
Gamma-BHC (Lindane)
Heptachlor
Heptachlor epoxide
Methoxychlor
Methylene chloride
o-Dichlorobenzene
p-Dichlorobenzene
Pentachlorophenol
Polychlorinated biphenyls (PCBs)
Simazine
Tetrachloroethene
Toluene
Toxaphene
trans-1 ,2-Dichloroethene
Trichloroethene
Trichlorofluoromethane
Vinyl chloride
Xylenes
Units | SJC- East
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
<0.50
< 0.50
<0.50
< 0.50
< 0.50
<0.50
< 0.50
<5.0
<0.56
< 0.56
<0.12
< 0.50
<2.0
<0.50
< 0.50
<0.50
< 0.01
<0.50
<0.01
< 0.01
<0.01
< 0.01
<0.50
<0.50
< 0.50
<1.0
ND
<0.12
<0.50
< 0.50
<0.5
< 0.50
<0.50
<1.0
< 0.50
ND
SJC- West
<0.50
< 0.50
<0.50
< 0.50
< 0.50
<0.50
< 0.50
<5.0
<0.60
< 0.60
<0.10
< 0.50
<2.0
<0.50
< 0.50
<0.50
< 0.01
<0.50
<0.01
< 0.01
<0.01
< 0.01
<0.50
<0.50
< 0.50
<1.0
ND
<0.10
<0.50
< 0.50
<0.5
< 0.50
<0.50
<1.0
< 0.50
ND
Whit. Nar.
<0.50
< 0.50
<0.50
< 0.50
< 0.50
<0.50
< 0.50
<5.0
<0.53
< 0.53
<0.11
< 0.50
<2.0
<0.50
< 0.50
<0.50
< 0.01
<0.50
<0.01
< 0.01
<0.01
< 0.01
<0.50
<0.50
< 0.50
<1.0
ND
<0.11
<0.50
< 0.50
<0.5
< 0.50
<0.50
<1.0
< 0.50
ND
Pomona
<0.50
< 0.50
<0.50
< 0.50
< 0.50
<0.50
< 0.50
<5.0
<0.53
< 0.53
<0.11
< 0.50
<2.0
<0.50
< 0.50
<0.50
< 0.01
<0.50
<0.01
< 0.01
<0.01
< 0.01
<0.50
<0.50
< 0.50
<1.0
ND
<0.11
<0.50
< 0.50
<0.5
< 0.50
<0.50
<1.0
< 0.50
ND
5 P
6 P
200 P
5 P
1 P
0.5 P
5 P
5 P
70 P
50 P
1 P
1 P
4 P
0.5 P
70 P
6 P
2 P
300 P
0.2 P
0.01 P
0.01 P
30 P
5 P
600 P
5 P
1 P
0.5 P
4 P
5 P
150 P
3 P
10 P
5 P
150 P
0.5 P
1750P
Arsenic
Barium
Cadmium
Total Chromium
Copper
Fluoride
Iron
Manganese
Mercury
Nickel
Nitrate + Nitrite nitrogen
Selenium
Silver
Zinc
ug/L
ug/L
ug/L
ug/L
ug/L
mg/L
ug/L
ug/L
ug/L
ug/L
mg/L
ug/L
ug/L
ug/L
0.347
61.6
< 0.20
0.74
3.00
0.446
66
23.5
0.00123
5.83
4.50
<1.00
< 0.20
52.4
0.592
26.9
< 0.20
0.83
5.69
0.708
51
25.4
0.00150
3.01
9.49
<1.00
< 0.20
47.0
0. 722
38.8
< 0.20
1.0
5.00
0.685
25
9.38
0.00245
7.83
6.59
<1.00
< 0.20
56.3
0. 295
34.5
< 0.20
0.83
5.47
0.342
29
6.17
0.00147
1.96
6.90
<1.00
< 0.20
62.3
10P
1000P
5 P
50 P
1000S
2 P
300 S
50 S
2 P
100 P
10P
50 P
100S
Other Constituents
Color
Surfactant (MBAS)
Gross alpha radioactivity
CU
Mg/L
pCi/L
9
<0.10
0.898
8
<0.10
1.40
13
<0.10
1.02
14
0.0083
0.670
15S
0.5 S
15 P
P = Primary Maximum Contaminant Level (health)
S = Secondary Maximum Contaminant Level (aesthetic)
Values with "<" were below the Reporting Detection Limit reported
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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.
2012 Guidelines for Water Reuse
D-45
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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 non-
potable 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.
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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)
2012 Guidelines for Water Reuse
D-47
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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.
Figure 1
Avocado farming area, west of Temecula, Calif. (Photo
credit: Graham Juby)
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
2012 Guidelines for Water Reuse
D-48
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Appendix D | U.S. Case Studies
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 Ib/ac,
respectively, based on present agricultural-use water
data.
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 Ib/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.
Primary
Treatment
•
Secondary
Treatment
Tertiary Disinfection
Treatment
Screen
RO Disinfection
Use
; Optional
IFeed
Belt Press Filtrate
Figure 3
Use of primary effluent as source water results in
higher nutrient concentrations in recycled water
Primary Secondary
Treatment Treatment
Tertiary
Treatment
•Mr
Disinfection
AgUse
RO Disinfection
Figure 2
Conventional approach to producing partially
desalted recycled water
Such nutrient application rates are much lower than
typical rates used in California for oranges, avocados
and grapes; which are 85, 116 and 33 Ib/ac (95, 130
and 37 kg/ha) for nitrogen, and 34, 61 and 38 Ib/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
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
2012 Guidelines for Water Reuse
D-49
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Appendix D | U.S. Case Studies
bbl/yr of oil, also reducing greenhouse gas emissions
by 2800 tons/yr (2,500 tonnes/yr) of carbon dioxide
equivalent (Jubyet 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 "do-
nothing" 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, MASS, USDA, August.
EFMA. 2007. European Fertilizer Manufacturers Association,
Harvesting Energy with Fertilizers, Brussels, Belgium.
Retrieved on August 29, 2012 from .
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.
2012 Guidelines for Water Reuse
D-50
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Water Reuse in the
Santa Ana River Watershed
Author: Celeste Cantu (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.
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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 system-
wide plan.
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Leo J. Vander Lans Water Treatment Facility
Authors: R. Bruce Chalmers, P.E. (COM 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 LBWRP LCWRP
TOC (mg/L)
Turbidity (NTU)
TDS (mg/L)
pH (SU)
TN (mg/L)
Nitrate (mg/L as N)
Ammonia (mg/L)
NDMA (ng/L)
1,4 Dioxane (ug/L)
6.7
0.48
703
7.9
9
6
1.5
291
RNR
7.5
0.50
787
7.9
9.3
5.3
2.0
296
2.55
Product
LVLWTF
0.44
0.07
83
8.12
2.05
1.74
0.22
4.9
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.
Title 22
Feed
To LACSD
To LACSD
To Alamitos
Blend' ^»- ^T
=5tatinn Final Product |
Stat'°n a-*™*' To LACSD
Pump Station gl
3 Sodium Hydroxide
Figure 1
LVLWTF process flow diagram (Photo credit: COM
Smith 2011)
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
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Appendix D | U.S. Case Studies
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.
Figure 2
LVLWTF site (Photo credit: COM Smith 2011)
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.
UF
FEED PUMP
RECOVERY RECOVERY MF
MF FEEDPUMP
FEED TANK
WASTE
EQUAL
Figure 3
MF and MF backwash treatment systems (Photo credit:
COM Smith 2012)
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.
Existing Primary RO
72:36 Array -3.7 mgd
Figure 4
Three stage RO system (Photo credit: SPI 2011)
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.
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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.
Figure 1
400 gpm Wastewater Pasteurization Demonstration
System in Ventura California (Photo credit: Greg
Ryan, Pasteurization Technology Group)
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]).
4
3.5
2.5
1.5
0.5
Filtered Effluent
Best Fit of Filtered Effluent (3rd deg Poly)
Unfiltered Effluent
125
135
165
145 155
Temperature (deg F)
Figure 2
Disinfection of total coliform in treated effluent
(Salveson, 2007)
175
Log Red u ction of See d ed M S 2
8.0
7.0
n n
Best Fit - Filtered Effluent, >=7.7 seconds contact time
Filtered Effluent Raw Data
A Unfiltered Effluent Raw Data
n .•
_
=a
y /
g^/ATJ
^f^_
140
170
150 160
Temperature (deg F)
Figure 3
Disinfection of MS2 Coliphage in treated effluent
(Salveson, 2007)
180
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Appendix D | U.S. Case Studies
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 8.
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.
2012 Guidelines for Water Reuse
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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:
7906; "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 sewage-
polluted 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 tree-
bearing 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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Appendix D | U.S. Case Studies
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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Appendix D | U.S. Case Studies
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
.
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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Appendix D | U.S. Case Studies
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
.
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
.
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 AWWAA/VEF 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
Us) 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-the-
art 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.
Figure 1
The Edward C. Little Water Recycling Facility is
located in El Segundo, California
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
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Appendix D | U.S. Case Studies
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 micro-
filtration 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.
Figure 2
Reverse osmosis treatment at the ECLWRF
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
water quality.
2012 Guidelines for Water Reuse
D-62
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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 wash-
down 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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Appendix D | U.S. Case Studies
Table 1 Typical water quality parameters
Parameter
Alkalinity, as CaCOS
Ammonia as N
Boron
Calcium
Chloride
Chlorine, Total
Iron
Magnesium
Manganese
Nitrate + Nitrite as N
Nitrate as N
Nitrite as N
Ortho Phosphorous,
Dissolved as P
PH
Phosphorous, as P
Potassium
Sodium
Specific Conductance
Sulfate
Temperature
Total Coliform
Total Kjeldahl Nitrogen
Total Organic Carbon
Units
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
SU
mg/L
mg/L
mg/L
mg/L
mg/L
°C
MPN/
100mL
mg/L
mg/L
Typical Range
50-150
0-0.4
0.2-0.4
40-70
65-170
1.5-4.0
0.05-0.6
5-20
0.003-0.08
5-30
5-20
0.01-0.05
0.04-0.3
6-8
0.04-0.4
10-20
90-200
360-1250
80-250
10-30
<1.0
0.2-2
4-8
HATER TWICE is NICE
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.
Denver's waler n loo precious to use only
wil'.V Wf'fn; d..iin..jyui y-i'l ly COlliCFVC
by using nxycW wpfor fix many jobs
around 1h* Ztsu— frdrn walf-
lo deanifig animal tiabitali!
Whet-*- dot'i trcyded water cornt I-
Treated wastewater, on lu wity to th* South Plattf
fovei. is.d-lwiluU lu (dv Pvm-t Watu' 'vtyx''"« p
to br < l^jmiHl *gain. AM«f a complex wmbht-ng amrf
filTcnrvg procc-u, the recycled waicr Istafe for
wildlife, irrigation, find our animal f
Figure 2
Public education signage (Photo credit: Denver Zoo)
"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)
2012 Guidelines for Water Reuse
D-64
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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 Denver-
metro 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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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.
SOS - source of supply
T&D - transmission &
distribution
Recycle
T&D
Potable
T&D
Recycle
Treatment
SOS
Potable
Treatment
Recycle
T&D
Potable
T&D
Recycle
Treatment
SOS
Raw Water
Figure 1
Water rates structure
Recycled Water Potable Water
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
Figure 2
Relative water rates by class of 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
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Appendix D | U.S. Case Studies
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.
2012 Guidelines for Water Reuse D"67
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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 Us) 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.
Figure 1
Cherokee Station (Photo credit: Xcel Energy)
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
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Appendix D | U.S. Case Studies
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
Alkalinity, Total as CaCOS
Ammonia as N
Boron
Calcium
Chloride
Chlorine, Total
Iron
Magnesium
Manganese
Nitrate + Nitrite as N
Nitrate as N
Nitrite as N
Ortho Phosphorous,
Dissolved as P
PH
Phosphorous, Total as P
Potassium
Sodium
Specific Conductance
Sulfate
Temperature
Total coliform
Total Kjeldahl Nitrogen
Total Organic Carbon
Units
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
SU
mg/L
mg/L
mg/L
mg/L
mg/L
°C
MPN/
100mL
mg/L
mg/L
Typical Range
50-150
0-0.4
0.2-0.4
40-70
65-170
1.5-4.0
0.05-0.6
5-20
0.003-0.08
5-30
5-20
0.01-0.05
0.04-0.3
6-8
0.04-0.4
10-20
90-200
360-1250
80-250
10-30
<1.0
0.2-2
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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D-69
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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 non-
detect 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)
Total Dissolved Solids TDS (mg/L)
PH
Sodium Adsorption Ratio, adjusted (SARadj)
Sodium - Na (mg/L)
Chloride - Cl (mg/L)
Boron - B (mg/L)
Bicarbonate - HCO3 (mg/L)
Nitrate - NO3-N (mg/L)
0.89
570
6.92
3.7
130
99.3
0.28
66
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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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, well-
managed, and active-growing turf grasses serve as
bio-filtration systems for removal of excess nitrate.
Figure 1
Soil nitrate profile
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 often 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 (CaCI2), 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,
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Appendix D | U.S. Case Studies
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. So/7 Testing Five Years after
Irrigation with Recycled Water.
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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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Appendix D | U.S. Case Studies
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
PWT&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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Appendix C | International Case Studies
Table 1 Summary of recommended improvements
and Year Pipeline Improvements Improvements Storage Improvements
Phase 1
2010
Phaqp ?
1 1 IQOC L.
2015
Phase 3
2020
Phase 4A
2025
Phase 4B
2025
• Coal Creek Area/Rio
Grande Pit Connection
Sand Creek Park
Connection
• Signature Park
Connection
n/a
• Delaney Farm Pump
Station
• Main Iliff Pump Station
• Main Iliff Service Main
• Wheel Park Connection
• Heather Gardens GC
Connection
• Heather Ridge GC
Connection
• 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
SCWRF Pump
Station Expansion
(6.5 mgd)
n/a
• Delaney Farm
Pump Station
(6.5 mgd)
• Iliff Pump Station
(2.2 mgd)
n/a
n/a
• 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)
• 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)
• Delaney Farms Operational
Storage (5.0 MG)
• Wheel Park Pond (2.5 MG)
• Heather Gardens GC Pond
(1 .6 MG)
• Heather Ridge GC Pond
(4.1MG)
• 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)
Additional
Irrigated
Acres
197
306
364
486
1416
Total
Construction
Cost1'2
$11.4 M
$16.1 M
$39. 5 M
$82.8 M
$97. 6 M
2
Construction costs are in 2008 dollars
Construction costs for each phase include costs for previous phases
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Water Reuse Barriers in Colorado
Author: Cody Charnas (COM 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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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).
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Figure 1
Natural wastewater treatment and reuse system (Image: Courtesy of Andropogon Associates)
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Appendix D | U.S. Case Studies
Figure 2
View of new building extension (Photo: Courtesy of
Andropogon Associates)
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
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Appendix D | U.S. Case Studies
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.
Figure 3
View of rain garden and pond (Photo: Courtesy of
Andropogon Associates)
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.
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South District Water Reclamation Plant
Authors: R. Bruce Chalmers, P.E. (COM 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: COM Smith 2008)
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Appendix D | U.S. Case Studies
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
TOC
IDS
Total Nitrogen
Ammonia
Phosphorus
(Mg/L)
NDMA (ng/L)
FDEP
PartV
(mg/L)
3
500
10
N.R.
N.R.
N.R.
DERM WQ
Standards
(mg/L)
N.R.
500
N.R.
0.5
N.R.
(< 10 proposed)
N.R.
DERM
CTLs
(mg/L)
N.R.
N.R.
2.8
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.
SDWRP
N Chlorlne/Cnloramine
(Optional)
Threshold
Inhibitor
Deep Bed Chlorine \
Sand Fillers Contact Tank
Sodium
Bisulfite
Sulluric
Acid
Cartridge
Filter
Reverse
Osmosis
SDWWTP"
Hydrogen
Peroxide
Sodium
Hydrox.de Water
Storage
Tank
Lime Product Water Effluent
Stabilization Pump Station toMetrozoo
(Optional) Recharge Facilities
Ion Exchange
Pump Station
(Optional)
SDWRP
Figure 2
SDWRP process flow diagram (Photo credit: COM Smith/Hazen and Sawyer 2008)
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Appendix D | U.S. Case Studies
Table 2 Major system design information
System Number Capacjty Comments
of Trams H >
MF
RO
IX
UV-AOP
13+1
4+1
12+2
4+1
1.9(1.76)
5.25
1.75 (1.5)
5.25 (4.2)
94% Recovery
3-stage, 1 2 gfd
85% Recovery
Regeneration
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
A
C
MF Offer
UV Offer
Site Preparation/ Earthwork
Off-site Pipelines
SDWRP
SDWWTP Deep Injection
Well
$13,400,000
$4,100,000
$18,800,000
$23,000,000
$195,100,000
$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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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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Appendix D | U.S. Case Studies
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
25cfu/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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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 (COM 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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Appendix D | U.S. Case Studies
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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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)
I Respondents Who Said Yes to Benefit
Reclaimed Water Benefits (a) Number Said % of Total No. of
[ Yes Responses Respondents (b)
1 . Have a guaranteed and reliable water source
2. Able to conserve fresh water for their other uses
3. Able to irrigate more frequently
4. Able to apply more water to the crop/lawn/ landscape
5. Better able to supply water to crops during drought
6. Irrigation or water costs are lower
7. Our permitting requirements have been reduced
8. Net income is higher than with traditional water source
9. Fertilization costs are lower
1 0. Revenue is higher than with traditional water source
1 1 . Business increased during fresh water restrictions
1 2. Better able to protect crops from freezing
1 3. Crop yield or product quantity has been higher
14. Pounds of juice per acre is higher
15. Our production cost is lower
1 6. Water storage costs are lower
1 7. Quality of crop/lawn/landscape/product is higher
25
25
17
15
5
17
3
11
7
9
4
2
2
1
1
3
3
68%
68%
63%
56%
50%
46%
30%
30%
26%
24%
24%
20%
10%
10%
10%
8%
8%
37
37
27
27
10
37
10
37
27
37
17
10
20
10
10
37
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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Appendix S | U.S. Case Studies
demonstrated that there are cost-savings and value-
added 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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Appendix D | U.S. Case Studies
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 green-
shaded 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
.
Reclaimed Water Benefit Cost
Calculator
for Irrigation
Economic Comparison of Reclaimed Water Versus Next Available Water Source For
Irrigation by Agricultural, Recreation and Aesthetic Water Users
Row
No.
(1)
70
71
72
73
74
75
Benefit or Cost Item
(2)
Next
Available
Water
Source
(NAWS)
(3)
Reclaimed
Water Used
Instead &
Other Sources
if Applicable
NAWS Minus
RW/Other
(Except A.
which is
RW/Other
(RW/Other) minus NAWS)
(4)
(5)
E. Nitrogen Fertilizer Cost Savings - Annual:
N Fertilizer Cost per Ton: |
Nitrogen concentration in ppm or mg/l of
Irrigation Water (for reclaimed water, obtain
from utility. For NAWS, use available info or
assume 0):
Percent of Nitrogen in water that is taken up by
the plant:
Nitrogen Fertilizer Cost Savings Per
1,000 gallons of irrigation water:
Nitrogen Fertilizer Cost Savings
due to N in applied water - Annual
$552
0
50%
$0.00
$0
$552
6
50%
-$0.015
-$1,258
$0.015
$1 ,258
Figure 1
Partial screen shot of reclaimed water benefit cost calculator for irrigation, nitrogen fertilizer cost
savings module
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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 non-
potable 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 Us). 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.
Figure 1
Areas irrigated with potable water and RCID
reclaimed water (Photo credit: Reedy Creek Energy
Services Surveying and Mapping Department)
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
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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).
Figure 2
Allocation of reclaimed water to RIBs and reuse
distribution system
Water Quality Standards and
Treatment Technology
RCID employs a five stage Bardenpho™ 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
(5ocysts/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 at-
grade 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.
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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 Standard
Arsenic
Barium
Cadmium
Chromium
Flouride
Lead
Mercury
Nitrate as N
Selenium
Silver
Sodium
Volatile Orqanics
Ethylene dibromide
(EDB)
Para-dichlorobenzene
Vinyl chloride
1,1 -dichloroethane
1,2-dichloroethane
1,1,1-trichloroethane
Carbon tetrachloride
Trichloroethane
Tetrachloroethane
Benzene
Trihalomethanes
Total Trihalomethane
(TTHM)
Orqanics
Endrin
Lindane
Methoxychlor
Toxaphene
2,4-D
2,4,5-TP (Silvex)
Radioloqicals
Gross Alpha
Radium 226 and 228
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
uq/L
uq/L
uq/L
uq/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
uq/L
Mg/L
ug/L
Mg/L
pCi/L
pCi/L
<0.0015
<0.0025
<0. 00038
<0.006
0.31
<0. 00054
<0. 00005
0.391
<0.0015
<0.0005
160
<0.01
<1.0
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<1.0
<0.5
66.7
0.021**
0.097
<0.0021
<0.090
<0.12
<0.11
<2.1
0.75
<0.0015
0.0028
<0. 00038
<0.006
0.08
<0. 00054
<0. 00005
0.57
<0.0015
<0.0001
73.8
<0.006
<1.0
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<1.0
<0.5
59.4
<0.02
0.03
<0.02
<0.09
0.32
<0.087
<1.6
0.2
<0.0015
0.0035
<0. 00038
<0.006
0.19
<0. 00054
<0. 00005
0.664
0.0018
<0.0001
71.9
<0.009
<1
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<1.0
<0.5
179**
<0.019
<0.025
<0.024
<0.09
<0.091
<0.056
<1.3
0.7
<0.0015
0.0015
<0. 00038
<0.006
0.03
<0. 00054
<0.00005
0.688
<0.0015
<0.0001
82.3
<0.009
<0.1
<0.083
<0.15
<0.082
<0.00015
<0.082
<0.068
<0.099
<0.05
46.5
<0.003
<0.0031
<0.024
<0. 00022
<0.099
<0.05
1.3
0.7
<0.0015
0.0015
<0. 00038
<0.006
0.02
<0. 00054
<0.00005
0.402
<0.0015
<0.0001
77.9
<0.0081
<1
<0.71
<0.5
<0.5
<0.5
<0.5
<0.55
<1.0
<0.58
54.2
<0.01
<0.005
<0.019
<0.96
<0.037
<0.06
1.6
0.8
0.05
1
0.01
0.05
4
0.05
0.002
10
0.01
0.05
160
0.02
75
1
7
3
200
3
3
3
1
80
0.02
4
100
5
100
10
15
5
Secondary Chemistry
Chloride
Copper
Iron
Manqanese
Sulfate
Zinc
pH (units)
Total Dissolved Solids
Foaminq Aqents
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
104
0.0021
0.12
0.0038
50.9
<0.025
7.4
391
0.045
142
<0.0015
0.13
<0.0015
60.3
<0.025
6.2
410
<0.006
166
0.0015
0.1
0.0017
53.9
0.025
7.5
419
0.021
110
<0.0015
0.15
<0.0015
55.3
<0.025
7.6
402
0.059
114
0.0015
0.16
<0.0015
47.1
0.025
8.15
414
0.12
250
1
0.3
0.05
250
5
6.5-8.5
500
0.5
mq/L are milliqrams per liter or parts per million
uq/L are microqrams 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 drinkinq water standard
N/A indicates that an averaqe value was not possible to calculate due to a mix of results above and below detection
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Marco Island, Florida,
Wastewater Treatment Plant
Authors: Jennifer Watt, P.E. (General Electric); Solomon Abel, P.E. (COM 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 backyard 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).
Figure 1
Marco Island WWTP membrane trains (Photo credit:
Jeff Poteet)
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 high-
quality reuse water, reducing the demand of potable
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Appendix D | U.S. Case Studies
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 Us)
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 Us) 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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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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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
PH
Total Suspended
Solids
Total Nitrogen
Total Phosphorus
Carbonaceous
Biochemical
Oxygen Demand
Dissolved Oxygen
Monthly/Annual
Limit
6.0 -8.5 s.u.
15.0mg/L
2.31 mg/L
0.20 mg/L
10 mg/L
3.8 mg/L
2011 Wetlands
Discharge
7. 24 s.u.
1.07 mg/L
1.00 mg/L
0.026 mg/L
0.67 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.
Water Management Districts
| | SWFWMO
SWFWMO Counties
Figure 1
Water management districts and SWFWMD counties
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.
Figure 2
Project location
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.
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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 Mclntosh Power
Plant used 4.79 mgd (210 L/s). The remainder was
combined with 1.85 blowdown water from the
Mclntosh 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
2012 Guidelines for Water Reuse
D-100
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Appendix D | U.S. Case Studies
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. 2070
Reuse Inventory.
Florida Statutes. Section 403.086 (4).
Southwest Florida Water Management District. 2006.
Southern Water Use Caution Area Recovery Strategy.
2012 Guidelines for Water Reuse D"101
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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
14.00
12.00
10.00
^8.00
;
y
2*6.00
5
'•* 4.00
2.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
DPotable Water
D Supplemental Water (Reclaimed)
{Reclaimed Water
ISupplementalWater(Ground Water)
Figure 1
Average monthly water use by source
2012 Guidelines for Water Reuse
D-102
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Appendix D | U.S. Case Studies
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.
f
8.0 -
7.0 -
5.0 -
4.0 -
3.0 -
2.0 -
1.0 -
0.0 -
Prior to Urban Reuse
1
U
After Urban Reuse
1
140% -
130% -
X 120% -
o
% 110% -
8
100% -
90% -
80% -
70% -
Figure 3
Potable water use
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
1— Reclaimed Water Factor
I— Potable Water Factor
criteria.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 2
Comparison of seasonal variations in reclaimed and potable water demands
2012 Guidelines for Water Reuse
D-103
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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 low-
flow 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.
2012 Guidelines for Water Reuse
D-104
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Appendix D | U.S. Case Studies
-Clearwater Consumption - - - SWFWMD Maximum Consumption Goal
T3
O
Q 125 -
Q
E
=3
O
O
0>
03
_
_a
S
o
Q.
Figure 1
Potable water consumption compared to District goals
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.
2.00EI07
1.50Ci07
1.00Ci07
5.00006
O.OOE+00
Figure 2
Total water demand
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
2012 Guidelines for Water Reuse
D-105
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Appendix D | U.S. Case Studies
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.
2012 Guidelines for Water Reuse D"106
-------
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, paniculate 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 Miami-
Dade 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)
2012 Guidelines for Water Reuse
D-107
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Appendix D | U.S. Case Studies
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.
Tu*o» Pom Unl! « S 7 Annu*l Suit Deposition Plume
Wnler Lirw 1-4 ttgmajVnoitf h
1 Turitoy Powl Pl»m PTOptrty 4-10ktfh&'rmnlh
10 - J?G wli.i'M";MI'i
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Figure 1
Surrogate for CECs deposition: predicted monthly
salt deposition from use of only Biscayne Bay water
for backup cooling (Photo credit: FPL, 2011)
2012 Guidelines for Water Reuse
D-108
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Appendix D | U.S. Case Studies
References
Energy Information Administration (EIA). 2011. International
Energy Outlook 2011. Retrieved on April 2, 2012 from
.
Florida Power & Light (FPL). 2011. Turkey Point Plant, Units
6 & 7, COL Application, Part 3, Environmental Report.
Retrieved on March 25, 2012 from
.
U.S. Nuclear Regulatory Commission (NRC). n.d. Turkey
Point, Units 6 and 7 Application. Retrieved on Sept. 5, 2012
from .
2012 Guidelines for Water Reuse D"109
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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.)
2012 Guidelines for Water Reuse
D-110
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Appendix D | U.S. Case Studies
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
Panhandle
Road
Constructed
Wetlands
E.L. Huie
Constructed
Wetlands
2002
2005
2006
2007
2010
Sites
North,
Central,
South
G
D, E, F
B, C, H, I
A
Wet
Area
(ac)
53
54
40
47
123
Capacity
(mgd)
4.4
3.5
2.6
3.2
8.1
Total
Capacity
(mgd)
4.4
17.4
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
Panhandle Road
Constructed
Wetlands
Limit Actual
(mg/L) (mg/L)
E.L. Huie
Constructed
Wetlands
Limit Actual
(mg/L) (mg/L)
Flow (MGD)
BOD6
TSS
NH3-N
TP
monitor
only
10/151
30/451
4/6'
(May-Oct.)
8/12'
(Nov.-Apr.)
2/31
1.35
1
4
0.03
0.59
monitor
only
1 0/1 51
15/22.51
1. 4/2.1 1
0.62
14.45
3
5
0.06
0.24
' Monthly/weekly averages
2 Annual average monitored only at the lake discharge
3 Average effluent data for 201 1
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
.
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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On the Front Lines of a Water War, Reclaimed Water Plays
a Big Role in Forsyth County, Georgia
Author: Daniel E. Johnson, P.E. (COM 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 (USAGE),
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 USAGE 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
BOD6
TSS
Fecal Coliform
PH
Turbidity
< 5 mg/L
< 5 mg/L
<23cfu/100mL
monthly geometric mean,
100 cfu/1 OOmL maximum per sample
6-9 standard units
<2NTU
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 cross-
connection 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 .
Georgia Water Council, Georgia Comprehensive State-wide
Water Management Plan, 2008.
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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
oxidizes organic materials.
and
• 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: in-
process 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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Appendix D | U.S. Case Studies
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
Figure 1
Water recovery schematic of The Coca-Cola Company
be
considered in the greater context of political, societal
and ecological dynamics (TCCC, 2012). Industry-
sponsored 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 non-
product 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
Alkalinity
PH
TDS
Turbidity
TOC
Color
Odor
Internal
Specification
85 mg/mL as
CaCO3
4.9 minimum
500 mq/l
0.3 NTU
0.5 mq/L
Sensory
Sensory
Average
27.72
6.32
34.91
0.11
0.17
Standard
Deviation
3.02
0.68
4.63
0.02
0.03
Acceptable
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
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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 Coca-
Cola Company, as well as local regulatory
requirements for each plant location.
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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 non-
existence 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 R-
2 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
.
Honolulu Board of Water Supply, Oahu Water Management
Plan Overview, May 31, 2006. Retrieved on Sept. 5, 2012
from
.
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
.
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.
.
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
.
State of Hawaii Department of Business, Economic
Development and Tourism, Visitor Statistics, 2010 Annual
Visitor Spreadsheet. Last Accessed January 2012.
.
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 .
2012 Guidelines for Water Reuse
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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.
Figure 1
The Fay School, Southborough, Massachusetts
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 pre-
treatment 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).
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Appendix D | U.S. Case Studies
18 '
g 1.
— in .
X o
10
t
\
\ l_
\ Fay School's Cost — V
K; \
"*Ss*--f ^
* 1- a
* "*"
00 3000 5000 7000 9000
Average Demand (gpd)
Figure 2
Cost of water per 1,000 gallons
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.
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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
Raw
Parameter Wastewater Effluent
BOD (mg/L)
TSS (mg/L)
TN (mg/L)
Turbidity (NTU)
221
286
64
<2
< 2
< 2
<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.
Figure 1
Gillette Stadium, Foxborough, Mass. (Photo credit:
Kathleen Esposito)
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 (38,000m3) 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
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Appendix D | U.S. Case Studies
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 .
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 (COM 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 Snowfluent™ developed by Delta Engineering of
Ottawa, Canada. Snowfluent™ 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).
Figure 1
CVSD District employee Joseph Puleo checks the
nozzles atop a snow gun tower. (Photo credit: David
Keith)
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
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Appendix D | U.S. Case Studies
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 year-
round operations using a smaller storage lagoon
facility.
Mapleton
Sewer District
S»?ay irrigation''&TIOW a
artc-water Treatment Facility
1461 Main Street
.
Figure 2
Mapleton Sewer District Wastewater Treatment Facility
sign (Photo credit: Gilles St. Pierre)
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 (CRWQCB-
CVR, 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,
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Appendix D | U.S. Case Studies
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
.
Maine Lagoons on Line. 2012. Retrieved on March 24, 2012
from .
Mt. Buller. 2012. Mt Buller Web Page. Retrieved on March
25, 2012 from
.
Nasaw, Daniel. 2011. Indians oppose 'recycled' sewage for
Arizona skiing. BBC World News. Retrieved on October 19,
2011 from .
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
-------
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 Us) for phosphorus removal, for more efficient
operations and capacity to meet more stringent
effluent standards in the future.
Figure 1
Mankato WRF
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
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Appendix D | U.S. Case Studies
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 sealant 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/view-
document.html?qid=16079.
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Town of Gary, North Carolina, Reclaimed Water System
Authors: Leila R. Goodwin, P.E. (Town of Gary) and Kevin Irby, P.E. (COM Smith)
US-NC-Cary
Project Background
The town of Gary, 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, Gary 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 Gary treats wastewater for Gary,
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 Gary WRF and South Gary WRF have
reclaimed water systems consisting of piping systems
as well as bulk reclaimed water distribution stations.
The town of Gary'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).
Gary'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 Gary 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 Gary 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 Gary WRF reclaimed water service area
includes a 1.2-mgd (52.5-L/s) pump station at the
South Gary 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.
Figure 1
Bulk reclaimed water distribution station (Photo credit:
David Heiser)
Figure 2
New reclaimed water pumps at the WRF (Photo credit:
David Heiser)
Water Quality Standards and
Treatment Technology
The town of Gary's reclaimed water system was
designed to meet the state's mandatory treatment
standards (Table 1). Both WRFs treat wastewater
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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
BODS
TSS
NH3
Fecal coliform
Turbidity
Daily Maximum
15 mg/L
1 0 mg/L
6 mg/L
25cfu/100mL
10NTU
Maximum Monthly
Average
10 mg/L
5 mg/L
4 mg/L
14cfu/100mL
10NTU
Project Funding
The total project cost for the reclaimed water system
including both the North Gary and South Gary WRFs
was $11 million. The project was funded through the
town's capital improvement budget.
Reclaimed water in the town of Gary 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 Gary'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, Gary 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 Gary is currently expanding its reclaimed
water system into a third service area. The town of
Gary, 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
Gary's Thomas Brooks Park, the site of the USA
Baseball national training center. The service area
also includes some currently undeveloped portions of
northwestern Gary.
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 Gary, Wake County,
and Durham County. The portion of this project serving
the Wake County portion of Research Triangle Park
and some of western Gary 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 Gary.
COM Smith. 1997. Reclaimed Water and Wastewater Reuse
Program. Prepared for the Town of Gary.
COM Smith. 2000. Application for Modification to North Gary
Reclaimed Water System Non-Discharge Permit
WQ0017923. Prepared for the Town of Gary.
Town of Gary website. 2011. Retrieved on Sept. 4, 2012
from .
Wake County website. 2011. Retrieved on Sept. 4, 2012
from < http://www.wakeqov.com/>.
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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.
Water Use Breakdown (% vol)
1.2J-V0'7
• in product
• water treatment
* container cleaning
• evaporation
• landscape irrigation
•OP
9 utilities
a misc process water
cooling tunnels
Figure 1
Example output from Recon Water Profiler that
compares water use volume for different uses at a
beverage plant
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Appendix D | U.S. Case Studies
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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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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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 on-
site 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.
2012 Guidelines for Water Reuse
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Appendix D U.S. Case Studies
Waier is ['jumped into me wetland cell
where plants and microorganisms
reduce pollutants and remove
It also provides a raaging
zone which determines
if the water should flow
through the trickling filter
tor re-Ctrculation, through
tho wetland cell, or if it
should be processed
through to the drip
irrigation field.
Bam water is collected
from the roof lop. stored
in an underground cistern
and used to flush toilets
From the wetland cell, water flows to
the level adjust basin which controls
the amount of water contained in the
wetland cell.
Waslcwalcr from
the building flows
into a settling lank
where all solids settle
as sludge mat will
be decomposed by
microorganisms- The
1 .vastewatei
Hows to the flow
equalization tank
The flow equalization tank
evenly releases water to the
next step in the process,
balancing out the surges
from periodic overuse of the
facilities.
Altec re-circulation, clean water
flows into tho drip irrigation lank
and is sent lo a dnp irrigation
system thai waters tho landscape
.1 •: .. ' ,
Mlcrohtal otganifirns
leecl on the wastewater
sircram m moving
ammonia, phoshoriis,
and ntlrogon Irani ih«
Figure 1
Schematic of the WPEC system components (Photo credit: Rodale Institute and NEWVISION Communications)
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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.
(Figure 2). The system recycles 100 percent of the
wastewater that is produced by the facility's 140,000
annual visitors.
Figure 1
Main House (Photo credit: WEFTEC 2002)
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
Treatment facility (Photo credit: WEFTEC 2002)
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.
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Appendix D | U.S. Case Studies
Table 1 Typical water quality
BOD (mg/L)
TSS (mg/L)
TN (mg/L)
Turbidity (NTU)
350
350
75
—
Effluent
<5
<5
<10
< 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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Franklin, Tennessee
Integrated Water Resources Plan
Authors: Jamie R. Lefkowitz, P.E. and Kati Bell, PhD, P.E. (COM 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 Us) 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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Appendix D | U.S. Case Studies
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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340
Total Nitrogen Limit,
Summer Conditions
Existing Reuse
IWRP Reuse
Figure 1
Estimated reduction in nutrient loading to Harpeth River resulting from
increased effluent reuse
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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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
.
n IAA
2012 Guidelines for Water Reuse u~ '^
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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 Us). 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.
Golf courses,
3,166, 16%
Government
and other
irrigation,
3,678, 19%_^ | Rivers and
streams,
10,106, 51%
Industrial &
cooling,
2,702, 14%
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
BOD6
Turbidity
Fecal Coliform
Type I Standard
(Texas)
5 mq/L
3 NTU
<20cfu/100ml_
SAWS
Reclaimed Water
Quality
2 mq/L
<1 NTU
<2cfu/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,
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
potable water can cost $2 to 3/1000 gallons ($0.52 to
0.111 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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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 .
Eckhardt, Gregg. The Edwards Aquifer Website. Retrieved
on August 02, 2012 from .
2012 Guidelines for Water Reuse D"147
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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
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
Figure 1
Project schematic, Raw Water Production Facility - Big Spring Plant
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
paniculate 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.
2012 Guidelines for Water Reuse
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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
(TAG 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 Quality
Water TDS EC I Na Cl
Sources (ppm) (dS m1) SAR (ppm) (ppm) Soil Suborder Landscape Degradation
El Paso
Rio Grande
Fred Hervey
Haskell
Northwest
Alamogordo1
Odessa^
660
680
980
1200
1800
1650
0.9
0.9
1.6
2.2
2.7
2.4
3.2
3.7
7.3
11.0
2.0
1.9
110
150
250
350
310
330
92
180
280
325
480
520
Torrifluvents, Entisols
Calciorthid, Aridisols
Torrifluvent, Entisols
Paleorthid, Aridisols
Camborthid, Aridisols
Paleustal, Alfisols
Soil salinization
No problem (turf only)
Leaf damage, salinization
Leaf damage, salinization
Leaf damage, salinization
Leaf damage
These water sources contain substantial quantities of Ca and
Reclaimed water quality of this source changes with season
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
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 species-
dependent, 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. TR-
316:1-37 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. TR-
310, 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.
2012 Guidelines for Water Reuse
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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 pre-
flight system design and testing
(Straub et al., 2010). U.S. crews
USOS CABIN
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
BIOLOGICAL
PAYLOADS
| We
Urine '
! *
i
i
Wastewater
I
I
I
I
Potable water
ter Recovery System (WRS) '
URINE PROCESSOR
ASSEMBLY (UPA)
Vapor Compression
Distillation (VCD)
1 Distillate
I
I
I
I
I
WATER PROCESSOR
ASSEMBLY (WPA)
• Gas Separator I
• Participate Filter
• Multifiltration Beds '
• Volatile Removal Ass'y
(VRA)
Potable water
I i ' Oxygen Generation System (OGS)
I
I
I
Oxygen
OXYGEN GENERATOR
ASSEMBLY (OGA)
• Solid Polymer
Electrolysis (SPE)
• Module (PSM)
Water
C02 REDUCTION
Hydrogen SYSTEM (CRS)
• Sabatier Reactor Sub.
(SRS)
•CO2 MgmtSub. (CMS)
Carbon Dioxide
Figure 1
WRS and Oxygen Generator Assembly (OGS) process flow diagram
2012 Guidelines for Water Reuse
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Appendix D | U.S. Case Studies
(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.
Figure 2
Water recovery system on ISS
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 Ibs/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.
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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).
i.,
Figure 1
ERWSP wetland, May 2009 (Photo credit: Alan
Plummer Associates, Inc.)
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.
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Lake Texoma Inflow
Chapman Lake Inflow
•LakeTawakoni Inflow
• Major WWTPs
^ Diversion Point
—" Raw Water Transfer
Figure 2
ERWSP Flow Directions
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
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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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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.
Figure 1
Aerial view of the Occoquan Reservoir (Photo credit:
Roger Snyder, Manassas, Virginia)
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
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Appendix D | U.S. Case Studies
Figure 2
The UOSA Reclamation Plant provides an important source of water for the service area (Photo credit:
COM Smith for UOSA)
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 Us) 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
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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 water-
related 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
-------
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-VA-
Occoquan]. 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, the installation of nutrient removal
technology or the implementation of non-discharging
alternatives, such as water reuse.
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
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 regula-
tions 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, respec-
tively.
• 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 non-
biological 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 etseq., 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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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 low-
pressure/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
Effluent Limit
Parameter
BOD6 (mg/L)
TSS (mq/L)
D.O. (mg/L)
Filtration
Turbidity (NTU)
Disinfection
Total Coliform (MPN/
100mL)
Nitrogen Removal
Ammonia (mg/L)
Total Nitrogen (mg/L)
Monthly
Average
30
30
Weekly
45
45
Must be present
Monthly
Average
2
7-Day
Median
<2.2
Monthly
Average
3.3
10
Sample
Maximum
5
Sample
Maximum
23
Daily Maximum
5.7
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 re-
aeration, stream flow augmentation to Bell
Creek (Figure 1) to improve stream flows for
fisheries and habitat restoration.
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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.
Figure 1
Introduction of reclaimed water to Bell Creek (Photo
credit: Gray & Osborne, Inc.)
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.
Figure 2
Sequim Water Reclamation Facility expansion (Photo
credit: Gray & Osborne, Inc.)
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
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Appendix D | U.S. Case Studies
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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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
Table 1
Requirements for reclaimed water in Washington State
OXIDIZED
COAGULATED
(mg/L)
30
•*«*-
Must be
present
Yes
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.
FILTERED
Turbidity
(NTU)
2 NTU avg.
DISINFECTED
Total conform
(MPN/100mL)
7-Day Median | Single Sample
5 NTU max.
< 2.2
23
30
Must be
present
No
No
< 2.2
23
30
Must be
present
No
No
< 23
240
30
Must be
present
No
No
240
N/A'
1 Not applicable
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Appendix D | U.S. Case Studies
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
.
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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 community-
supported 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.
Figure 1
Greenhouse trial of Class A reclaimed water (Photo
credit: Dana Devin Clarke)
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.
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Appendix D | U.S. Case Studies
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.
•
S 0.4
Arsenic Cadmium Lead
Nickel
Figure 2
Metal concentrations in lettuce from field trial
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
(Figures).
Figure 3
Dr. Brown presenting study data at luncheon (Photo
credit: Jo Sullivan)
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.
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Appendix D | U.S. Case Studies
Figure 4
Harvesting potatoes after luncheon (Photo credit: Jo
Sullivan)
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 Septembers, 2012 at
.
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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.
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Appendix D | U.S. Case Studies
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 .
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Appendix C | U.S. Case Studies
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APPENDIX E
International Case Studies and International Regulations
List of Case Studies by Title and Authors1
Page No. 1 Text code
E-5
E-8
E-11
E-13
E-15
E-18
E-21
E-24
E-27
E-30
E-33
E-36
E-40
Argentina-Mendoza
Australia-Sydney
Australia-Graywater
Australia-Victoria
Australia-
Replacement Flows
Barbados-Economic
Analysis
Belgium-Recharge
Brazil-Car Wash
Canada-Nutrient
Transfer
China-MBR
Colombia-Bogota
Cyprus-Irrigation
Ghana-Agriculture
Case Study Title 1 Authors
Special Restricted Crop Area in Mendoza,
Argentina
Sewer Mining to Supplement Blackwater
Flow in a Commercial High-rise
Retirement Community Graywater Reuse
End User Access to Recycled Water via
Third Party-Owned Infrastructure
St Marys Advanced Water Recycling Plant,
Sydney
Economic Analysis of Water Reuse Options
in Sustainable Water Resource Planning
Water Reclamation for Aquifer Recharge in
the Flemish Dunes
Car Wash Water Reuse - A Brazilian
Experience
Water Reuse Concept Analysis for the
Diversion of Phosphorus from Lake Simcoe,
Ontario, Canada
Water Reuse in China
The Reuse Scenario in Bogota
Water Reuse In Cyprus
Implementing Non-conventional Options for
Safe Water Reuse in Agriculture in
Resource Poor Environments
Carl R. Bartone (Environmental
Engineering Consultant)
Colin Fisher (Aquacell)
Colin Fisher (Aquacell)
Geoff Jones (Barwon Water)
Stuart Khan, PhD (University of South
Wales) and Peter Chapman (Sydney
Water)
William Y. Davis and Jason Johnson,
P.E. (COM Smith)
Emmanuel Van Houtte, Intercommunale
Waterleidingsmaatschapij van Veurne-
Ambacht (Intermunicipal Water
Company of the Veurne Region, IWVA)
Rafael N. Zaneti, MSc; Ramiro G.
Etchepare, MSc; and Jorge Rubio, PhD,
DIG
(Universidade Federal do Rio Grande
doSul)
David C. Arseneau, P.Eng, MEPP
(AECOM); David K. Ammerman, P.E.
(AECOM); Michael Walters (Lake
Simcoe Region Conservation Authority)
Allegra K. da Silva, PhD (COM Smith)
and Liping Lin (GE Water and Process
Technologies)
Juan M. Gutierrez, MS (Javeriana
University) and Lucas Bolero, P.E.,
BCEE (COM Smith)
lacovos Papaiacovou and Constantia
Achileos, MSc (Sewerage Board of
Limassol Amathus); loanna loannidou,
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)
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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
List of Case Studies by Title and Authors1
Page No.
E-43
E-47
E-51
E-54
E-58
E-60
E-63
E-66
E-69
E-71
E-74
Text code
India-Delhi
India-Bangalore
India-Nagpur
Israel/Jordan-
Brackish Irrigation
Israel/Palestinian
Territories/Jordan-
Olive Irrigation
Israel/Jordan-AWT
Crop Irrigation
Israel/Peru-Vertical
Wetlands
Japan-Building MBR
Jordan-Irrigation
Jordan-Cultural
Factors
Mexico-Tijuana
Case Study Title
Reuse Applications for Treated Wastewater
and Fecal Sludge in the Capital City of
Delhi, India
V Valley Integrated Water Resource
Management: the Bangalore Experience of
Indirect Potable Reuse
City of Nagpur and MSPGCL Reuse Project
Managing Irrigation Water with High
Concentrations of Salts in Arid Regions
Irrigation of Olives with Recycled Water
Advanced Wastewater Treatment
Technology and Reuse for Crop Irrigation
Treatment of Domestic Wastewater in a
Compact Vertical Flow Constructed Wetland
and its Reuse in Irrigation
A Membrane Bioreactor (MBR) Used for
Onsite Wastewater Reclamation and Reuse
in a Private Building in Japan
Water Reuse and Wastewater Management
in Jordan
Cultural and Religious Factors Influence
Water Reuse
Water, Wastewater, and Recycled Water
Integrated Plan for Tijuana, Mexico
Authors
Priyanie Amerasinghe, PhD and Pay
Drechsel, PhD (International Water
Management Institute); Rajendra
Bhardwaj (Central Pollution Control
Board)
Uday G. Kelkar, PhD, P.E., BCEE and
MilindWable, PhD, P.E. (NJS
Consultants Co. Ltd.); and Arun Shukla
(NJS Engineers India Pvt. Ltd.)
UdayG. Kelkar, PhD, P.E., BCEE (NJS
Consultants Co. Ltd) and
Kalyanaraman Balakrishnan (United
Tech Corporation)
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)
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
Josef Hagin, PhD and Raphael Semiat,
PhD (Grand Water Research Institute
Technion - Israel Institute of
Technology, Haifa, Israel)
Ines Scares, 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)
Katsuki Kimura, Dr.Eng. and Naoyuki
Funamizu, Dr.Eng. (Hokkaido
University, Sapporo, Japan)
Bader Kassab, MSc (USAID Jordan)
and Ryujiro Tsuchihashi, PhD (AECOM)
Tom A. Pedersen (COM Smith)
Enrique Lopez Calva (COM Smith)
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Appendix E | International Case Studies
List of Case Studies by Title and Authors1
Page No.
E-76
E-79
E-82
E-85
E-88
E-90
E-93
E-96
E-99
E-102
E-104
E-107
E-110
E-112
E-114
Text code
Mexico-Mexico City
Mexico-Ensenada
Mexico-San Luis
Potosi
Pakistan-Faisalabad
Palestinian
Territories-Auja
Peru-Huasta
Philippines-Market
Senegal-Dakar
Singapore-NEWater
South Africa-
eMalahleni Mine
South Africa-Durban
Spain-Costa Brava
Thailand-Pig Farm
Trinidad and
Tobago-Beetham
United Kingdom-
Langford
Case Study Title | Authors
The Planned and Unplanned Reuse of
Mexico City's Wastewater
Maneadero Aquifer, Ensenada, Baja
California, Mexico
Tenorio Project: A Successful Story of
Sustainable Development
Faisalabad, Pakistan: Balancing Risks and
Benefits
Friends of the Earth Middle East's
Community-led Water Reuse Projects in
Auja
Assessing Water Reuse for Irrigation in
Huasta, Peru
Wastewater Treatment and Reuse for Public
Markets: A Case Study in Sustainable,
Appropriate Technology in the Philippines
Use of Wastewater in Urban Agriculture in
Greater Dakar, Senegal: "Adapting the 2006
WHO Guidelines"
The Multi-barrier Safety Approach for
Indirect Potable Use and Direct Nonpotable
Use of NEWATER
Turning Acid Mine Drainage Water into
Drinking Water: The eMalahleni Water
Recycling Project
Durban Water Recycling Project
Risk Assessment for Legionella sp. in
Reclaimed Water at Tossa de Mar, Costa
Brava, Spain
Sam Pran Pig Farm Company: Using
Multiple Treatment Technologies to Treat
Pig Waste in an Urban Setting
Evaluating Reuse Options for a Reclaimed
Water Program in Trinidad, West Indies
Langford Recycling Scheme
Blanca Jimenez-Cisneros, PhD
(Universidad Nacional Autonoma de
Mexico)
Leopoldo Mendoza-Espinosa, PhD and
Walter Daessle-Heuser, PhD
(Autonomous University of Baja
California)
Alberto Rojas (Comision Estatal del
Agua), Lucina Equihua
(Degremont S.A. de C.V.), Fernando
Gonzalez (Degremont, S.A. de C.V.)
Jeroen H. J. Ensink, PhD (London
School of Hygiene and Tropical
Medicine)
Elizabeth Ya'ari (Friends of the Earth
Middle East)
Daphne Rajenthiram (COM Smith);
Elliott Gall and Fernando Salas
(University of Texas) and Laura Read
(Tufts University)
Mary Joy Jochico (USAID) and Ariel
Lapus (USAID-PWRF Project)
Seydou Niang, PhD (Cheikh Anta Diop
University of Dakar)
Harry Seah, MSc and Chee Hoe Woo,
MSc (PUB Singapore)
Jay Bhagwan (Water Research
Commission)
Jay Bhagwan (Water Research
Commission)
Rafael Mujeriego, PhD (Universidad
Politecnica de Cataluna) and
Lluis Sala, (Consorci Costa Brava)
Pruk Aggarangsi, PhD (Energy
Research and Development Institute-
Nakornping, Chiang Mai University,
Thailand)
Matt McTaggart, P.Eng, R.Eng; Jim
Marx, MSc, P.E.; and Kathy
Bahadoorsingh, PhD, R.Eng (AECOM)
Afsaneh Janbakhsh, MSc, Cchem,
MRSC, Csci (Northumbrian Water Ltd,
UK)
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
List of Case Studies by Title and Authors1
Page No.
E-116
Text code
United Arab
Emirates-Abu Dhabi
Case Study Title
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 (COM 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
Australia
Australia
Brazil
Cyprus
India
Israel
Israel
Mexico
Mexico
Mexico
Spain
Thailand
Vietnam
Title of Regulations or Guidelines
Guidelines for Environmental Management:
Use of Reclaimed Water
Australian Guidelines for Water Recycling
RESOLUgAO No 54, DE 28 DE
NOVEMBRO DE 2005
TOUEQC; EAEYXOU ir]c; PuTrovar]c;
General Standards for Discharge of
Environmental Pollutants Part-A: Effluents
rmpnn y^ip
Normas Oficiales Mexicanas ordenadas por
Materia
Norma Oficial Mexicana Nom-001-Semarnat-
1996, Que Establece Los Lfmites Maximos
Permisibles De Contaminates En Las
Descargas De Aguas Residuales En Aguas Y
Bienes Nacionales
Law: NOM-003-Semarnat-1997
Spanish Regulations for Water Reuse
Pig Farm's Standard Waste Water Level
National Technical Regulation on Water
Quality for Irrigated Agriculture
Link to Country Regulations or Guidance
http://epa.vic.gov.au/our-
work/publications/publication/2003/november/464-2
http://www.ephc.aov.au/taxonomv/term/39/
http://www.aesa.pb.aov.br/leaislacao/resolucoes/cnrh/54 2005
criterios aerais uso aaua.pc
http://www.moa. aov.cv/moa/environment/environment.nsf/AII/2
6C40CAAAAEF746CC22578D1 003B1 FEA?OpenDocument
http://cpcb.nic.in/GeneralStandards.pdf
http://www.water.aov.il/Hebrew/ProfessionallnfoAndData/Wate
r-Qualitv/Paaes/treated waste water. aspx?P=print
http://www.iustice.aov.il/NR/rdonlvres/DF355FDA-0616-4D36-
B8D3-64F706C494C9/19866/6886.pdf
http://www.semarnat.aob.mx/LEYESYNORMAS/Paaes/nomsx
materia.aspx
http://www.bvsde.paho.ora/bvsacd/cd38/Mexico/NOM001ECO
L.pdf
www.conaqua.qob.mx
http://www.asersaaua.es/publicaciones/SpanishReaulationsfor
WaterReuseEN.pdf
http://ptech.pcd. ao.th/website/index.php?option=com content
&view=article&id=22:wwstd&catid=8:envlaw<emid=31
http://www.epe. edu.vn/file/C Documents%20and%20Settina
s CQ%2040 Local%20Settinas Application%20Data Mozilla
Firefox Profiles 6zquphxp.pdf
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2012 Guidelines for Water Reuse
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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 Id) 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 (ERAS), was
created in 1993 to regulate, control, and guarantee the
provision of water and sewerage services in the
Province of Mendoza. By means of ERAS' Resolution
35/96 (ERAS, 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 build-
own-operate-transfer (BOOT) concession from the
metropolitan water and sewerage company, Obras
Sanitarias de Mendoza (OSM), to the private operator
Union Transitoria de Empresas (LITE). LITE 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,
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E-5
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Appendix E | International Case Studies
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, LITE
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; ERAS, which
regulates and controls the provision of water and
sewerage services; and the Departamento General de
Irrigation (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
off ice 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, Republica de Argentina.
PAHO, Lima, Peru.
DGI. 2003. Anexo I: Reglamento de Area de Cultivos
Restringidos Especiales (ACRE). Resolucion No. 400/03,
Departamento General de Irrigacion, Mendoza, Argentina.
Egocheaga, L. and J. Moscoso. 2004. Una estrategia para la
gestion de las aguas residuals domesticas: haciendo mas
sostenible la proteccion de la salud en America 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). Resolucion 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.
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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
.
2012 Guidelines for Water Reuse E"7
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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
Make fcom Bond) S*vw Man
Figure 1
Bligh St Sewer mining and reuse schematic
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Appendix E | International Case Studies
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
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
.
World Health Organization. 2004. Guidelines for Drinking-
water Quality. World Health Organization, Geneva,
Switzerland. Retrieved on Sept. 5, 2012 from
.
2012 Guidelines for Water Reuse
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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<10mg/L
• TSS<10mg/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
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
-------
End User Access to Recycled Water via Third Party-
Owned 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
E. coli
PH
BOD
SS
Range
< 1000 org/100 ml
6 to 9
< 20 mg/L
< 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
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.
2012 Guidelines for Water Reuse
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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 ef a/., 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 ef
a/., 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 ef a/., 2010). This chemical
monitoring program demonstrated that key prioritized
chemicals of potential toxicological concern (including
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Appendix E | International Case Studies
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 ("cone 1", "cone 2" and "cone 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
•ooo
100 •
10 -
1 -
0.1
Dibromochloromethane
AOWR» 1DO ^'L
• i 3 L
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.
CaneS
Cent 1
UF inflm nt & FUrM*
RO lrfflu*nt
10 20
JO 50 TO
Percenlilt
90 95 W 99
LOR = limit of reporting
Figure 1
Example of comprehensive monitoring of chemical contaminants in the St Marys
Water Recycling Plant
Institutional/Cultural
Considerations
Planning approval for the
overall project included condi-
tions 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 com-
munity 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 con-
sulted indigenous Aboriginal
groups on managing
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Appendix E | International Case Studies
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 SJ.
Khan. 2010. "Chemical monitoring strategy for the
assessment of advanced water treatment plant
performance." Water Science & Technology: Water Supply,
10(6): 961-968.
Khan, SJ. 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., DJ. Roser, NJ. 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).
2012 Guidelines for Water Reuse
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Economic Analysis of Water Reuse Options in Sustainable
Water Resource Planning
Authors: William Y. Davis and Jason Johnson, P.E. (COM 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
Costs
Benefits
NPV
BC Ratio
ERR
$270
$427
$156
1.58
11.8%
$371
$500
$129
1.35
9.7%
$398
$500
$102
1.26
8.8%
$322
$490
$168
1.52
11.6%
$350
$490
$141
1.40
10.5%
$381
$500
$119
1.31
9.6%
Dollars are U.S. million
Discount rate is 6%
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Appendix E | International Case Studies
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 (multi-
criteria 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
BBlffi
Life-cycle Costs (US$ million)
Rank (1=lowest)
NPV* (US$ million)
Rank (1=lowest)
BC Ratio*
Rank (1=lowest)
EIRR*
Rank (1=lowest)
Total MCA Score
Rank (1=lowest)
Unweighted Score
Unweighted Rank
Weighted Score
Weighted Rank
$270
1
$156
2
1.58
1
11.8%
1
700
2
7
1
1.78
1
$371
4
$129
4
1.35
4
9.7%
4
653
5
21
4
4.70
5
$398
6
$102
6
1.26
6
8.8%
6
723
1
25
6
2.50
2
$322
2
$168
1
1.52
2
1 1 .6%
2
605
6
13
2
4.73
6
$350
3
$141
3
1.40
3
10.5%
3
679
3
15
3
3.00
3
$381
5
$119
5
1.31
5
9.6%
5
676
4
24
5
4.30
4
* At 6% discount rate
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E-19
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Appendix E | International Case Studies
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
COM, Benefit-cost Analysis for the West Coast Sewerage
Project Master Plan (WCSMP), completed for the Barbados
Water Authority, 2009.
2012 Guidelines for Water Reuse
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Water Reclamation for Aquifer Recharge
in the Flemish Dunes
Author: Emmanuel Van Houtte, Intercommunale Waterleidingsmaatschapij van Veurne-
Ambacht (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-Andre. 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-Andre, 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-Andre 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
Conductivity (uS/cm)
Chloride (mg Cl/l)
Sulphate (mg SO4/I)
Total hardness (°F)
Nitrate (mg NO3/I)
Nitrite (mg NO2/I)
Ammonia (mg NH4/I)
Total phosphorous (mg P/l)
Infiltration water
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.
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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
Conductivity (uS/cm)
PH
Total Organic Carbon (mg/l)
Total hardness (mg/l as CaCOS)
Chlorides (mg /I)
Fluorides (mg/l)
Sulfates (mg/l)
Nitrate (mg NO3/I)
Ammonia (mg NH4/I)
Phosphate (mg PO4/I)
Silicium (mg SIO2/I)
Total trihalomethanes (ug/l)
Aluminum (ug/l)
Chromium (ug/l)
Copper (ug/l)
Lead (ug/l)
Mercury (ug/l)
Nickel (ug/l)
Sodium (mg/l)
Zinc (ug/l)
Totale Coliform bacteria
(counts/100 ml)
E. coli (counts/100 ml)
HPC 22°C (counts/ml)
Infiltration Water
45 (<10-89)
6.29(5.28-6.86)
0.4 (0.1 -1.1)
<0.5
3.2 (1.0-4.7)
<0.2
<1
2.5(<1 -6.3)
0.13 (0.03-0.38)
<0.1
0.3 (0.1 -0.4)
3.8 (1.2-6.7)
12 (2-59)
<2.5
<5
<5
<0.2
<3
10.5 (4.5-17.7)
<20
0
0
<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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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.
Prevcrcni
NaOCl
N.-iOCI
NILCI
To
Figure 1 Process scheme of Torreele
2012 Guidelines for Water Reuse
E-23
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Car Wash Water Reuse - A Brazilian Experience
Authors: Rafael N. Zaneti, MSc; Ramiro G. Etchepare, MSc; and Jorge Rubio, PhD, DIG
(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.
Figure 1
Car wash water reclamation system - Total storage
capacity: 2,640 gallons (10 m3). Stages include: 1.) Hand-
operated 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.
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
etal., 2004).
The FCF principle is to encourage rapid formation of
floes, followed by flotation using fine (micro) bubbles to
remove particles. Chlorine is then used to disinfect the
FCF treated wastewater. The floe 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 CI2 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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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 (IDS)
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
PH
TSS, mgl_ '
TDS, mgl_ '
Turbidity, NTU
Total coliforms,
CFU/10
E. co//, CPU/
100 ml1
7. 4 ±0.8
89 ±54
344 ±25. 5
103 ±57
3.1E±5
2.1E±4
Reclaimed
Water
7. 3 ±0.5
8±6
388 ± 42
9±4
3.3E±4
7.4E±2
Examination
Methods*
-
2540 D
-
21 SOB
9223 B
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 CPU 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
<400mg.l_"1) (Nace1975).
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
(550m2) 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 floes 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 Brasflia: 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.
2012 Guidelines for Water Reuse
E-25
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Appendix E | International Case Studies
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.
2012 Guidelines for Water Reuse E"26
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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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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:
stormwater management and agricultural controls, as
part of a potential credit trading program. Figure 2
provides a comparison of water reuse scenario
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?
$10,000
A,;ii::i: lur.-i I
-------
Appendix E | International Case Studies
Table 1 Summary of reuse scenario costs and phosphorus removal rates
Annual Percent Phosphorus
25-year Life Phosphorus Phosphorus 25-year Removal Cost
Cycle Cost Removed Reduction Phosphorus Effectiveness
Reuse Scenario ($C AD 2010) (kg/yr) (%/year)1 Removal (kg) ($/kg P)
KeswickWPCP Sod Farm
Irrigation
Barrie Reuse for New Urban
Development
Uxbridge Brook WPCP Land
Application
$5.4-$10.4MM
$4.7-$9.5MM
$3.2-$6.4MM
116-184
12.6
25-49
22%-35%
0.50%
25%-49%
2,900-4,600
315
625-1,225
$1,85042,250
$14,950430,200
$5,08045,200
1 Compared to current phosphorus loading levels
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.
2012 Guidelines for Water Reuse
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Water Reuse in China
Authors: Allegra K. da Silva, PhD (COM 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 mid-
21 st century, per capita water resource will decrease
to 1.4 ac-ft (1,760m3), 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.
Figure 1
Hohhot MBR facility (Photo credit: Courtesy of GE
Water and Process Technologies)
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
2012 Guidelines for Water Reuse
E-30
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Appendix E | International Case Studies
requirements for the industrial cooling water
application. The JRWP uses a The Zee-Weed®-
membrane fiber has a nominal pore size of 0.04|jm,
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.
Figure 2
Beijing MBR facility (Photo credit: Courtesy of GE
Water and Process Technologies)
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.
2012 Guidelines for Water Reuse
E-31
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Appendix E | International Case Studies
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
.
2012 Guidelines for Water Reuse E"32
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The Reuse Scenario in Bogota
Authors: Juan M. Gutierrez, MS (Javeriana University) and
Lucas Bolero, P.E., BCEE (COM Smith)
Colombia-Bogota
Project Background or Rationale
Bogota 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 Bogota River. This will
have many benefits, including making the water quality
suitable for reuse for agricultural irrigation. In addition,
as the Bogota 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 Bogota 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 Bogota 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 Bogota River, which
has already received a large amount of partially
treated or untreated wastewater discharged by smaller
towns located north of Bogota. The existing irrigation
infrastructure is operated by the environmental
regional authority, Corporacion Autonoma Regional
(CAR).
Several years ago, some power agencies developed a
hydroelectric generation scheme to use water from the
Bogota River, taking advantage of the river's 3,280 ft
(1,000 m) drop in the area south of Bogota, 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 Mufia 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 Bogota
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
Figure 1 shows the main components of the Bogota
River wastewater treatment scheme including the
agricultural and power generation schemes associated
with the Bogota 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 Bogota 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 Bogota River.
Water Quality Standards and
Treatment Technology
As the regulating agency for the Bogota 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
Bogota River water for Class 4 use (restricted
agricultural irrigation)
Table 1 Water quality requirements for the use of
Bogota River water for Class 4 use (restricted
agricultural irrigation)
Parameter | Unit
PH
BOD
Total conforms
Nitrites
Suspended solids
Aluminum
Arsenic*
Beryllium*
Boron
Cadmium*
Cobalt
pH units
mq/L
MPN/100mL
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
Allowable
Level
4.5-9.0
<50
< 20000
< 10
<40
<5
<0.1
<0.1
< 0.3-0.4
< 0.01
<0.05
Parameter Unit ^Levf^
Copper*
Chromium (Cr+6)
Fluoride
Iron
Lithium
Manganese
Mercury
Molybdenum
Nickel
Lead
TDS
Selenium
Vanadium
Zinc*
mq/L
mg/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
mq/L
<0.2
< 0.1
<1
<5
< 2.5
<0.2
<0.01
<0.01
<0.02
< 0.1
< 3000
<0.02
<0.1
< 2
* Based on CL 96/50, the concentration of an element or
compound that produces a mortality rate of 50% in
bioassays lastinq 96 hours.
Project Funding and Management
Practices
Because water from the Bogota River plays such a big
role in Colombia's energy generation, and the
wastewater from Bogota contributes up to 50 percent
of the Bogota River average flow, the sanitation of the
Bogota River has become a national priority project.
And, because there are so many different agencies
and institutions that benefit from the river (the Bogota
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 Bogota 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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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 Bogota River
water include increased salinity of the soils, making
them less fertile than they were originally.
References
Corporacion Autonoma Regional de Cundinamarca (CAR).
2006. "Acuerdo 43 de 2006 de la CAR: Clasificacion
de Usos del Agua Para La Cuenca del Rio Bogota y
Valores de Los Parametros de Calidad a Aplicar
por Clase." Retrieved on Sept. 5, 2012 from
.
OPTIMIZAClON
ALCANTARILLADO
CUENCA SALITRE
INTERCEPTOR
TUNJUELO
m~ EN CONSTCUGClGN
• • POHCONSTRUIR
^ CQNSTRUIDO
Figure 1
Components of the Bogota 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 Muna reservoir (on the right) is the source for the hydropower complex.
2012 Guidelines for Water Reuse
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Water Reuse in Cyprus
Authors: lacovos Papaiacovou and Constantia Achileos, MSc (Sewerage Board of
Limassol Amathus); loanna loannidou, MSc (Larnaca Sewerage and Drainage Board);
Alexia Panayi, MBA (Water Development Department); Christian Kazner, Dr.lng.
(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,
Figure 1
Installed dam capacity and corresponding average
precipitation per decade (prepared from WDD
statistics) (Hochstrat and Kazner, 2009)
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 re-
abstracted 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
201 Oa). 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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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
Mm /yr
Municipal wastewater
treatment plants
Rural wastewater treatment
plants
Total
Annual water recycling
46
13
59
52
51
14
65
69
16
85
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,
2008 b).
Table 2 Cyprus guidelines for irrigation urban reclaimed water from agglomerations with population less than
2000 population equivalent (K.D.P. 269/2005)
No
1
2
3
4
5
Type of Crops
All crops [a>
Amenity areas of
unlimited access and
vegetables eaten
cooked (b)
Crops for human
consumption and
amenity areas of limited
access
Fodder crops
Industrial crops
BOD
mg/L
1 1°
10
15**
20
30*
20
30**
[B]
50
70**
(0) _
SS
mg/L
10
10
15**
30
45**
30
45**
-
-
-
Fecal coli-
forms/100ml
5
15**
50
100**
200
1000*
1000
5000**
1000
5000**
3000
10000**
3000
10000**
Intestinal
worms/L
Nil
Nil
Nil
Nil
Nil
-
-
B&SM
Tertiary and disinfection
Tertiary and disinfection
Secondary, disinfection and
storage >7 days or Tertiary and
disinfection.
Secondary, disinfection and
storage >7 days or Tertiary and
disinfection.
Stabilization-maturation ponds
with total retention time >60 days
Secondary and Disinfection
Stabilization-maturation ponds
with total retention time >60 days
(A)
(B)
(a)
(b)
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)
Mechanized methods of treatment (activated sludge etc.)
Stabilization ponds
Irrigation of leafy vegetables, bulbs and corms eaten uncooked is not allowed
Potatoes, beetroots, colocasia
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Appendix E | International Case Studies
Table 3 Reused effluent quality characteristics
included in the discharged permits for
agglomerations with population above 2000 p.e.
(WDD, 2008)
Parameter
BODS (mq/l)
COD (mg/l)
Suspended solids (mq/l)
Conductivity (/jS/cm)
Total Nitrogen (mq/l)
Total Phosphorous (mq/l)
Chlorides (mq/l)
Fat and oil (mq/l)
Zinc (mq/l)
Copper (mq/l)
Lead (mq/l)
Cadmium (mq/l)
Mercury (mq/l)
Chromium (mq/l)
Nickel (mq/l)
Boron (mq/l)
E. Coliforms
Eqqs of intestinal worms
Residual Chlorine (mq/l)
PH
Maximum
permitted
value
10
70
10
2200
15*
10"
300
5
1***
0.1
0.15
0.01
0.005
0.1
0.2
1
5/1 00 ml
Nothinq/l
1****
6.5-8.5
Frequency
of analyses
1/1 5 days
1/1 5 days
1/1 5 days
1/1 5 days
1/1 5 days
1/1 5 days
1/ month
1 /month
2/year
2/year
2/year
2/year
2/year
2/year
2/year
2/year
1/1 5 days
4/year
1/1 5 days
3/week
for discharge in sensitive areas and into the sea
maximum level 10 mq/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 (loannidou 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 over-
pumped aquifers. In addition, treated wastewater
standards must be revised in order to address a wider
variety of substances of concern, such as micro-
pollutants.
Table 4 Selling rates of treated effluent from tertiary treatment plants (WDD, 2008)
I Existing selling Rate of Suggested selling rate of fresh not
Tertiary Treated filtered water from governmental
1
2
3
4
5
6
7
a. For irrigation divisions for agricultural
production
b. For persons for agricultural production
For sports
For irrigation of hotels green areas and
gardens
For irrigation of golf courses
For pumping from an underground aquifer
recharged by treated effluent
For over consumption for items 1 to 5
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 1 0%
5
7
15
15
21
8
Increase by 50%
15
17
34
34
34
56
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Appendix E | International Case Studies
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 .
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 .
loannidou 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 lll(l) 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 loanna 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 (201 Oa) Ministry of Agriculture, Natural Resources and
Environment, Water Development Department, Water
Demand Management. Retrieved on Sept. 5, 2012 from
.
2012 Guidelines for Water Reuse
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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 (Raschid-
Sally 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 low-
income 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.
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
Table 1 Non-conventional health-protection control measures and associated pathc
i reductions
Control Measure
Pathogen
Reduction
(log units) Notes
A. Wastewater treatment
B. On-farm options
Crop restriction (i.e., no
food crops eaten uncooked)
On-farm water treatment:
(a) Three-tank system
(b) Simple sedimentation 0.5-1
(c) Simple filtration 1-3
Method of wastewater application:
(a) Furrow irrigation 1-2
(b) Low-cost drip irrigation 2-4
(c) Reduction of splashing
Pathogen die-off (cessation) 0.5-2
per day
C. Post-harvest options at local markets
Overnight storage in
baskets
Produce preparation prior to
sale
D. In-kitchen produce-preparation options
Produce disinfection 2-3
Produce peeling
Produce cooking
6-7 Reduction of pathogens depends on type and degree of treatment selected.
6-7 Depends on (a) effectiveness of local enforcement of crop restriction, and
(b) comparative profit margin of the alternative crop(s).
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.
Sedimentation for -18 hours.
Value depends on filtration system used.
Crop density and yield may be reduced.
Reduction of 2 log units for low-growing crops, and reduction of 4-log units for
high-growing crops.
1-2 Farmers trained to reduce splashing when watering cans used (splashing adds
contaminated soil particles on to crop surfaces which can be minimized).
Die-off between last irrigation and harvest (value depends on climate, crop
type, etc.).
0.5-1 Selling produce after overnight storage in baskets (rather than overnight
storage in sacks or selling fresh produce without overnight storage).
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.
Washing salad crops, vegetables and fruits with an appropriate disinfectant
solution and rinsing with clean water.
2 Fruits, root crops.
5-7 Option depends on local diet and preference for cooked food.
Sources: Amoah et al. (2011).
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.
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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.
F 49
2012 Guidelines for Water Reuse
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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 [bid]) and demand of
48.8 bgd (189 bid) 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 [ml_d]) presently. Municipal
sewage generation is estimated at 981 mgd (3,800
ml_d), with a treatment capacity of about 594 mgd
(2,300 ml_d). 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 ml_d), 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(168mLd)
• 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
Sewer Network
Untreated
S
c
r
e
e
n
Grit Chamber
Excess Sludge
PrimarySedimentation Tank
Sludge Drying Beds
Sludge Digester
I
Aeration Tank
I
I
I
Secondary Sedimentation Tank
I
Biogas Generation
Treated Wastewater
Figure 1
Flow diagram depicting the wastewater treatment pathway at the Okhla STP
Table 1 Performance evaluation of five sewage treatment units at Okhla STP
Capacity Flow TSS COD BOD TSS COD BOD TSS COD BOD
Phase mLd mLd pH mg/L mg/l mg/l Con pH mg/L mg/L mg/L Con mg/L mg/L mg/L
I
II
III
IV
V
54.55
72.73
136.38
168.2
204.57
39.09
40.91
136.98
159.11
181.84
7.3
7.4
7.4
7.3
7.3
498
291
647
480
480
517
486
551
515
515
204
207
222
249
249
1440 7.8
1510
1480
1590
1590
7.7
7.6
7.8
7.7
21
83
76
32
27
54
108
153
62
51
10
48
45
12
19
1460
1400
1470
1540
1530
95.8
71.5
88.3
93.3
94.4
89.56
77.78
72.23
87.96
90.1
95.1
76.8
79.7
95.2
92.4
TSS = Total suspended solids; COD = Chemical oxygen demand; BOD = Biological oxygen demand; Con = Conductivity
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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 by-
products 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 ml_d) 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 Total coliform
(mg/L) BOD(mg/L) (MPN/100 mL) pH
Class A
Class B
Class C
Class D
Class E
6
5
4
4
NA
2
3
3
NA
NA
50
500
5000
NA
NA
6.5-8.5
6.5-8.5
6.5-8.5
6.5-8.5
6.5-8.5
Free
ammonia
(mg/L)
NA
NA
NA
1.2
NA
Conductivity SAR (mg/L)
NA
NA
NA
NA
2.25
NA
NA
NA
NA
26
NA
NA
NA
NA
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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
References
Central Pollution Control Board (CPCB). 1986. General
Standards for Discharge of Environmental Pollutants Part-A:
Effluents. Retrieved on Sept. 5, 2012 from
.
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
.
Delhi Jal Board. 2010. Retrieved on Sept. 5, 2012 from
http://www.delhi.gov.in/wps/wcm/connect/DOIT DJB/dib/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.ora/files/publications/wsp-esi-
india.pdf
F 4fi
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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 non-
conventional 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 ml_d)
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 ml_d). 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 ml_d), 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 ml_d)
of water. In Phase II, a new treatment plant at the
same location is being constructed to treat 145 mgd
(550 ml_d) 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
Table 1 Current and projected water demand and
availability of fresh water for the BWSSB
Year
2001
2007
2015
2021
2036
Population
million
5.4
7.5
8.8
10
12.5
Demand
MLd
870
1219
1720
2125
2550
Available Shortfall
mLd mLd
540
840
1500'
1500
1500
310
379
220
615
1050
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)
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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
Figure 2
During the pilot study, water quality testing was
conducted
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).
Parameter
Concentration
Effluent from Effluent from tertiary
secondary Treatment (Tavarekere Arkavathy River
treatment Plant)1 (reclaimed water, (7 km upstream of
(V Valley Plant) | which is discharged to river)
Reservoir)
TG Halli Reservoir
(values at the
reservoir intake to
WTP)
BOD mg/L
COD mg/L
Sulfate mg/L
Magnesium mg/L
Phosphate mg/L
Ammonia mg/L
TDS mg/L
Fecal conforms
#/100mL
E. CO//MPN/
100mL
22
65
25
28
1.8
25
450
>1600
>400
1.6
8
13
19
0.6
5
228
2
3
12
27
86
63
2.8
8
320
> 1600
>600
9
22
27
16
1.4
8
300 N/A
> 1 600 N/A
> 600 N/A
Reclaimed water that is discharged to river
N/A indicates data was not collected
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Appendix E | International Case Studies
Present BWSSB planning activities include:
• Improvements in V Valley STP to achieve
nutrients removal from the current volume of 36
mgd (135 ml_d), pumping of tertiary treated
water to Tavarekere to undergo advanced
treatment, including plans for UF and GAC
adsorption.
• Construction of a 36 mgd (135 ml_d) 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 IDS 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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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 on-
line. The existing percent consumption of water for
various uses at the power station is shown in Figure 1.
Existing Fresh WaterConsumption
Domestic
14%
Losses
6%
Ash handling
9%
Boiler feeding
3%
Cooling
towers
68%
Figure 1
Percent consumption of water by type of use for the
power station
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.
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Appendix E | International Case Studies
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 buy-
in from both Nagpur Municipal Corporation (NMC) as
well as MSPGCL that reuse is effective and feasible.
The pilot plant was constructed by Mis. Triveni
Engineering and Industries Ltd., using Memcor/
Siemens ultrafiltration unit that received secondary
treated wastewater from the NMC's existing
Bhandewadi STP.
84.64
Figure 2
Pilot setup for Nagpur water reuse scheme
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).
Ash handling Cooling water
make up
TOTAL
Figure 3
Total reuse potential at the power plant for ash
handling and cooling water make-up by 2015
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.
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Appendix E | International Case Studies
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).
m *ppx 249 Mto by ?G'' «
Figure 4
Government of Maharashtra published a written policy
paper in support of water reuse
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
No. Module Description
1
2
3
4
5
A
B
C
D
E
Construction of Kolhapurtype
collection weir, intake structure, sump
and pump house, and miscellaneous
works
Construction of sewage treatment plant
(for primary and secondary treatment)
Construction of micro filtration tertiary
treatment plant
Construction of tertiary water sump,
pump house, transmission main up to
Koradi 8.60 Kms, storage tank at
Korado, and other miscellaneous
works
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
COM, 2007.
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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 salinity-
excess 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 AI-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) NaCI. 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,and1.48mM.
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
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.
0.0 0.5 1.0 1.5
Relative irrigation water (l/ETni
Figure 1
Relative total biomass production of peppers
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.
60
.. 50
OJ
8 40
> 30
g
^ 20
a;
^ 10
0
• pepper
• melon
i Bean
R'= 0.8811
R'= 0.9942
0 50 100 150
Irrigation ievel {% ETp)
Figure 2
Fruit yield of three crops grown in Jordan
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.
.
"Hi 60
g 50
I 40
| 30
I 20
_ 10
f
S
6827 65.20
-j
ab
H~
ab
60.42
-\~
be
50.40
I
~
-
0 mg B Kg-1s oil 1 mg B Kg-1s oil 2 mg B Kg-1s oil 4mg B Kg-1s oil 6 mg B Kg-1s oil
Treatments
n Roots a Stems D Leaves n Fruits(LSD=11.24)
Figure 3
Dry matter (DM) g plant1 accumulation in organs of
bell pepper
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
etal, 2008).
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Appendix E | International Case Studies
1.2
re
E
>
.8
i
S .4
0)
a:
.2
0.0
EC 9
3 6 9 12 15
Boron in irrigation water (mg L" )
18
Figure 4
Biomass production of tomatoes
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,
GrantM24-014.
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 Iso-
yield 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.
pepper
melon
1.8
1.6
1.4
1.2
Ir1-0
-i 0.8
0.6
0.4
0.2
0.0
8 10
ECWSnr1
Figure 5
Compensation presentation of Iso-yield curves for
irrigation water salinity
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
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Appendix E | International Case Studies
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 RJ. 2008.
"Combined effect of salinity and excess boron on plant
growth and yield". Plant and Soil. 304, 73-87.
2012 Guidelines for Water Reuse
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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
470mm (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
PH
EC
NH4-N
NO3-N
Total N
K
P
Cl
Na
SAR
ds m '
mgL-1
R»™ W«ehr
7.7(0.3)
1.65 (0.13)
4.8(6.8)
15.2(3.9)
19.9(6.0)
29.6(2.2)
5.8(1.8)
323 (30)
198(25)
4.9(0.8)
7.5 (0.2)
0.9 (0.2)
0.0 (0.0)
3.4 (2.2)
3.4 (2.2)
4.4 (2.8)
0.0 (0.0)
168(56)
81 (28)
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 Ib (2.1 to 4.2 kg) (1686-3372 Ib/ac or 1890-
3780 kg/ha) in the '"On" years (2006, 2008) in
"Leccino." The "Barnea" trees had similar oil yields,
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
ranging from 4.4 to 9.7 Ib/tree (2.0 to 4.4 kg/tree)
(1606-3533 Ib/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.
So/7 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 etal., 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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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, AI-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 (HCI) cleaning for removal of
inorganic scaling and backwash cycles. The operation
included chlorination of the UF feed as an anti-
biofouling 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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Appendix E | International Case Studies
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 guality
Depth (cm) Sec. treat, effluent UF permeate
EC (dS/m)
0-20
20-40
3.24
3.01
2.83
2.71
Mix UF-RO
50-50
1
1.14
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:
EC, dS/m
SAR
Sec effl.
16
25
UF permeate
9
20
UF-RO
70-30
6
16
UF-RO
30-70
5
12
RO permeate
2
3
Table 3 Crop yields (tons per hectare) for plots irrigated with different blends of reclaimed water at
the Arad site, Israel
Irrigation Water
Sec. treat, effluent
UF permeate
UF- RO 70-30
UF- RO 30-70
RO permeate
Watermelon
28
36
34
44
50
Garlic I Corn grain
24
30
30
32
37
7.8
10.7
10.1
10.3
11.3
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Appendix E | International Case Studies
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-Jordanian-
Israeli 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 Palestinian-
Jordanian-lsraeli 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.M. 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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Treatment of Domestic Wastewater in a Compact Vertical
Flow Constructed Wetland and its Reuse in Irrigation
Authors: Ines Scares, 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 ef a/., 2008;
Sklarz eta/., 2009; Zapater eta/., 2011). The diversity
and dynamics of the RVFCW bacterial community
were analyzed to enhance our understanding of the
treatment efficiency and stability (Sklarz ef a/., 2011),
and a mathematical model that can be used as a tool
to design and operate these systems was formulated
(Sklarz ef a/., 2010). Lastly, possible effects of
irrigation with RVFCW effluent on soil properties were
assessed (Sklarz, 2009). This research was carried
Plastic Beads
(40 on)
Lime Pebble;
(5cm)
Reservoir —
Recirculatton
Pump
Irrigation Pipe
Figure 1
Schematic representation of the field RVFCW
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
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Appendix E | International Case Studies
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.
Raw
(influent) Effluent Israeli
Parameter (mg L1) Mean (SE) Mean (SE) Standard*
TSS
BOD6
COD
TN
NH4+-N
NO2-N
NO3-N
DO
PH
EC (mS cm"1)
E. coli
(CPU 100 ml1)
103(11)
178(19)
200(13)
36(2)
29(2.4)
BD**
0.3 (0.0)
0.2 (0.1)
7.4 (0.0)
0.96(0.1)
1x106
6.8(1.0)
6.2 (0.9)
18(2.6)
27(1.1)
1.3(0.4)
0.62 (0.1)
23 (0.9)
8.2 (0.2)
7.6 (0.1)
0.94(0.1)
5.4***
10
10
100
25
20
1.4
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 macro-
and 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 ef a/.,
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
BOD5m"2d"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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Appendix E | International Case Studies
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. Scares.
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.
Scares. 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. Scares 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. Scares.
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
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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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Appendix E | International Case Studies
Domestic
water supply
| Restaurants ] 1 SBR trealmeni |
Office and cooling
~* tower system
HjTo
Recli
imed water
Activated
cartoon
Black water
1
1
I
•( Flal-sheet HBR p— **
1
'- -1 - ,
ublic sewer
» Excess sludge
Figure 3
Wastewater reuse system flow diagram
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 urn.
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
Odor
Color and transparency
E. coli
Residual chlorine (mg/L)
BOD (mg/L)
COD (mg/L)
5.8-8.6
Not abnormal
Almost colorless and
transparent
Must not be detected
0.1 (free)
0.4 (combined)
<20
<30
Table 2 Water quality observed in the treatment system
Raw
Parameter Wastewater Effluent
PH
Odor
E. coli
BOD (mg/L)
SS (mg/L)
n-Hex (mg/L)
Color (color unit)
Turbidity (turbidity unit)
6-8
215
215
43
7.7 (6-8)
Not abnormal
Not detected
<1.0 (<10)
<1.0(<5)
<1.0(5)
4(<10)
<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
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Appendix E | International Case Studies
of the difficulty in treatment. Unfortunately, the amount References
of "clean" graywater produced in the building is not PubNc Building Association. 2005. Design of wastewater
sufficient to cover the amount needed for toilet reclamation and rainwater harvest systems (in Japanese).
flushing. To fill the gap, graywater produced in
restaurants is also included as the source of reclaimed Kimura, K., Mikami, D. and Funamizu, N. 2007. "Onsite
water at the cost of pretreatment. Wastewater Reclamation and Reuse in Individual Buildings
in Japan." In: Proceedings of 6 Conference on Wastewater
Reclamation and Reuse for Sustainability, Antwerp, Belgium,
October 9-12, 2007.
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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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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 AI-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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Cultural and Religious Factors Influence Water Reuse
Author: Tom A. Pedersen (COM 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 water-
related 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
2012 Guidelines for Water Reuse
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Appendix E | International Case Studies
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.
Figure 1
Irrigated alfalfa field in Wadi Mousa, Jordan (Photo
credit: Tom Pedersen, COM Smith)
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
.
Abu-Awwad, Ahmad M.2006. RIAL Project Presentations.
April 2006.
Hashemite Kingdom of Jordan Geography and Environment.
2012. Retrieved on Sept. 6, 2012 from
.
INFAD. 2012. Wastewater Treatment. World Fatwa
Management and Research Institute, Islamic Science
University of Malaysia. Retrieved on March 23, 2012 from
.
Maplecroft, 2012. Retrieved on March 23, 2012 from
-------
Appendix E | International Case Studies
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
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Water, Wastewater, and Recycled Water Integrated Plan
for Tijuana, Mexico
Author: Enrique Lopez Calva (COM 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
Comision Estatal de Servicios Publicos 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 Us). 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 non-
potable uses were conceptually designed for
conventional activated sludge followed with additional
filtration and hypochlorite disinfection.
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Appendix E | International Case Studies
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 multi-
agency 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 COM Smith.
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The Planned and Unplanned Reuse of
Mexico City's Wastewater
Author: Blanca Jimenez-Cisneros, PhD (Universidad Nacional Autonoma de Mexico)
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 Us).
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
(Jimenez, 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 (Jimenez, 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
paniculate 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 (Jimenez and Chavez, 2004)
2012 Guidelines for Water Reuse
E-76
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Appendix E | International Case Studies
Mexico City total Water Use: 85.7 m3/s
5 m3/s Groundwater from Lerma
21 % Industrial
7.7 m3/s Reclaimed wastewater 45% Urban
34 % Environmental
15 m Vs from Cutzamala
1 m3/s Local rivers
\|%J
^Vk^^Jtt
III' r-«V-:,rv
•trf
60 m3/s of Sewage + storm water
2,240 masl
I
Mexico Valley Aquifer
30 m3/s Over exploitation
57 m3/s: 41 m3/s through the water
network and 16 m3/s directly
pumped by farmers and industries
Figure 1
Use of water in Mexico City and the Tula Valley
2,100 to 1,700 masl
^•••^
Tula Valley Aquifer
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; Duranetal., 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.
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E-77
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Appendix E | International Case Studies
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].
Jimenez, B. and Chavez, 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.
Jimenez, 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.
Duran-Alvarez, J.C., Becerril E., Castro V., Jimenez 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 Jimenez 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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Maneadero Aquifer, Ensenada, Baja California, Mexico
Authors: Leopoldo Mendoza-Espinosa, PhD, and Walter Daessle-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
(Daessle 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 (Jimenez, 2005).
In order to explore and integrate water management
alternatives such as water markets, reuse and
seawater desalination, an optimization model was
employed (Medellfn-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 NOM-
014-CONAGUA-2003 (DOE, 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
2012 Guidelines for Water Reuse
E-79
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Appendix E | International Case Studies
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. Comision Estatal de Servicios
Publicos 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 (Medellfn-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
Daessle LW, Sanchez EC, Camacho-lbar VF, Mendoza-
Espinosa LG, Carriquiry JD, Macfas V. & Castro P. (2005)
Geochemical evolution of groundwater in the Maneadero
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Appendix E | International Case Studies
coastal aquifer during a dry year in Baja California.
Hydrogeology J., 13, 584-595.
Daessle 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 Federacion (2009). Norma Oficial
Mexicana NOM-014-CONAGUA-2003, Requisitos para la
recarga artificial de acufferos con agua residual tratada. 18-
agosto-2009.
Jimenez, B. (2005). Treatment technologies and standards
for agricultural wastewater reuse: a case study in Mexico.
Irrigation and Drainage, 54, S23-S33.
Medellfn-Azuara, J., Mendoza-Espinosa, L. G., Lund, J. R.,
and Ramfrez-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.
Medellfn-Azuara, J., Howitt, R., Waller-Barrera, C. Mendoza-
Espinosa, 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-Borbon 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. & Daessle,
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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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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Table 1 Main water quality standards for agricultural and industrial reuse 2007-2011
Parameter | Raw Wastewater*
TSS mg/L
BOD6 mg/L
COD mg/L
PTOTAL mg/L
TKN mg/L
Fecal Coli/100 mL
Total hardness mg/L
Silica mg/L
188 (±76)
275 (±99.5)
51 8 (±259)
8.7 (±3.9)
32.6 (±9.6)
4.8.10y(±1.3.10')
111.3 (±19.3)
104 (±20.3)
Tenorio Tank
Effluent to Reuse
in Agriculture**
28.8 (±10.6)
31 (±7.3)
84 (±19)
6.5 (±0.2)
22. 3 (±5.1)
161 (±402)
Not measured
Not measured
Criteria for
Agricultural
Reuse
30
40
Not reguired
15
25
1000
Not reguired
Not reguired
Reclaimed Water
to Power Plant*
3.58 (±3.06)
2.87 (±2.05)
15. 8 (±14. 45)
1.3 (±0.9)
1.5 (±3. 87)
18.4 (±16.6)
105. 6 (±24. 2)
64. 9 (±9. 3)
Criteria for
Industrial
Reuse in
Power Plant
10
20
60
2
15
70
120
65
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-operate-
transfer) 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/1 OOOgal (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
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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 Potosf water availability will be
increased by 10 mgd when the power station transfers
all their groundwater rights to the city, for potable use.
References
Medellfn P. (2003) Tanque Tenorio, 10 anos despues, Pulso
de San Luis Potosf, 4a Edition
Equihua L. O. (2006) Reuso de agua en la agriculturay en la
industria en Mexico: Caso del Proyecto San Luis Potosi,
Foro del Agua, 2006
Diario Oficial de la Federacion (2009) Actualization de la
disponibilidad media anual de agua subterranea acuffero
(2411) San Luis Potosi, Estado de San Luis Potosi
Diaz de Leon U. (2008) Saneamiento integral y reutilizacion
del agua en la ciudad de San Luis Potosi Mexico, Expo
Zaragoza, 2008
Rojas A. (2011) Experiencia de reuso del agua tratada en la
Zona Metropolitana de San Luis Potosf., Jornadas tecnicas
sobre la recarga artificial de acufferos y reuso del Agua,
Instituo de Ingenierfa UNAM.
Figure 1
Aerial view of Tenorio Tank, WWTP, and land irrigated
with reclaimed water (Photo credit: Degremont)
Figure 2
Tenorio Tank with different species of migratory birds
(Photo credit: Degremont)
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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
study showed an increased risk of intestinal nematode
infection, and in particular hookworm infection, in
wastewater farmers (OR = 31.4, 95% Cl 4.1-243) and
their children (OR = 5.7, 95% Cl 2.1-16) when
compared to farming households using regular (non-
wastewater) 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, co//7gram of produce.
Higher concentrations of E, coli (14.3 E, co//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 far-
mers and consumers of produce can be reduced by
proper irrigation water management and implementa-
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Appendix E | International Case Studies
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 P.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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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.
Figure 1
FoEME's Auja Environmental Education Center
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 sand-
filled 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 2
Graywater reuse system
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Appendix E | International Case Studies
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).
7 W
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r ^-.j-'i: J*'.
drosos (...)
Figure 3
FoEME's graywater system installation manual in
Arabic
Figure 4
Graywater workshop for youth at Auja Center
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.
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Assessing Water Reuse for Irrigation in Huasta, Peru
Authors: Daphne Rajenthiram (COM 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.
Figure 1
Location of Huasta, Peru
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
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Appendix E | International Case Studies
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 June-
August). 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.
Figure 2
Existing WWTP
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.
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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 N° 002-
2008-MINAM.
Figure 3
Community meeting
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.
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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.
Figure 1
Location of water reuse - the Muntinlupa
City public market
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
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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.
Table 1 Philippine DAO-35 Class C wastewater
discharge requirements
Figure 2
The public market was also the demonstration site of
the use of "coco-peat" for wastewater filtration
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.
Color
Temperature (max rise
in degree Celsius in
RBW)
pH (range)
COD
Settleable Solids
(1-hour)
5-Day 20°C BOD
Total Suspended
Solids
Total Dissolved Solids
Surfactants (MBAS)
Oil/Grease (Petroleum
Ether Extract
Phenolic Substances
as Phenols
Total Coliforms
Pt-Co units
°C rise
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
MPN/100mL
Class C
Requirements
< 150
<3
6.5-9.0
< 100
<0.5
< 50
< 70
—
<5.0
<5.0
< 0.1
< 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.
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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
.
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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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).
Figure 1
Hydrogeology and field situation (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 Iog10 pathogen reduction through sets of
measures:
• Wastewater treatment with 3-4 Iog10 pathogen
reduction
• Die off (delay between last irrigation and
harvesting) with 3-4 Iog10 pathogen reduction
• Washing of produce with 1 Iog10 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
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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).
Figure 2
Loading narrow well with raw wastewater (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
eta/. 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
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Appendix E | International Case Studies
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 CI/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
('utilisation saine des eaux usees dans I'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
I'agriculture periurbaine de Dakar, Senegal. These de
doctoral. Faculte des Geosciences et de I'Environnement.
Institut de Mineralogie et de Geochimie. Universite 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.,
Monies, C.R. and Melfi, A.J., 2009. Sodicity and salinily in a
Brazilian Oxisol cullivaled wilh sugarcane irrigated wilh
waslewaler. Agricullural Water Managemenl, 96(2): 307-
316.
Ndiaye, M.,L. 2009. Impacls sanilaires des eaux d'arrosage
de I'agricullure urbaine de Dakar (Senegal). Terre el
Environnemenl. Vol. 86. Insilul Forel/ Deparlemenl de
Mineralogie/Deparlemen de Geologie el Paleonlologie.
Seclion des Sciences de la Terre, Universite de Geneve.
Niang, S., Epole, M., Mfone, N., Pfeifer H. R., Ndiaye, M.,L.,
Gueye-Girardel, A., Diarra, K., Gaye, M. L., Dieng,Y., Niang,
Y., Tall H. 2009. Effecliveness of Ihree conslrucled wellands
for Irealmenl of faecal sludge liquid al Ihe experimenlal planl
of LATEU-IFAN Ch.A.Diop/Dakar. Scienlific report. FNS
Swilzerland.
Pfeifer, H. R. and Niang, S. 2009. Use of waslewaler in
urban agricullure in Ihe Dakar area, Senegal: an
interdisciplinary sludy towards suslainablilily Scienlific Final
report. Projecl FNS Swilzerland 2005-2009.
Vengosh, A., 2003. Salinizalion and Saline Environmenls. In:
B.S. Lollar (Editor), Environmenlal Geochemislry. Trealise
on Geochemislry. Elsevier-Pergamon, Oxford.
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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
• NE Water
• 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 will be fully treated and
provides a consistent good quality secondary
effluent as feedwater for NEWater production;
• More than 85 percent of used water is used
from domestic sources to provide additional
safety through dilution
• Comprehensive secondary wastewater
treatment is used to provide consistent good
quality effluent for NE Water 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
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 NE Water'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.
1 Water Reclamation Plants in Singapore refer to treatment
plants that provide secondary treatment to wastewater, via the
activated sludge process.
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Table 1 Quality of NEWater since year 2000
Sievers 820 TOC Analyser
Total estrogen
NGCMS 1124
0.003
<0.003
Estrones (E1)
H9/L
NGCMS 1124
0.001
<0.001
17p-estradiol (E2)
NGCMS 1124
0.001
<0.001
Ethinylestradiol (EE2)
NGCMS 1124
0.001
<0.001
Ibuprofen
LC-MS/MS
0.005
<0.005
Naproxen
ug/L
LC-MS/MS
0.005
<0.005
Gemfibrozil
ug/L
LC-MS/MS
0.005
<0.005
N-nitrosodimethylamine (NDMA)
ng/L
PTV-GC/MS
<2to10
1,4 Dioxane
ug/L
USEPA8270C
<1
Methyl Tertiary Butyl Ether (MTBE)
ug/L
USEPA8260B
<5
Polychlorinated biphenyls (PCBs)
ug/L
USEPA8082
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
.
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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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
(BMP 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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Appendix E | International Case Studies
Kleinkopje Colliery
Greenside Colliery
Landau Colliery
South Witbank Colliery
MINE WATER
STORAGE
TREATMENT PLANT
. .
Emalahleni
Municipal
Reservoirs
Supply to local
mining operations
Sludge and brine
disposal or re-use
Figure 1
Schematic diagram of key component of the reclamation approach (Source: Gunther and Mey 2006)
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.
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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 manage-
ment, environmental management, wastewater treat-
ment 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.
Figure 1
Construction of the Durban Wastewater Recycling
Plant (Photo credit: Ethekweni Metro Water Services)
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
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Appendix E | International Case Studies
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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E-105
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Appendix E | International Case Studies
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.,
Saaren.aovender@veoliawater.com.
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Risk Assessment for Legionella sp. in Reclaimed Water at
Tossa de Mar, Costa Brava, Spain
Authors: Rafael Mujeriego, PhD (Universidad Politecnica de Cataluha) 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 "Atencion: 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 publicly-
owned 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.
Figure 1
Reclaimed water use at Tossa de Mar dog shelter
(Photo credit: Lluis Sala)
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
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Appendix E | International Case Studies
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/1 OL and 200 cfu/100ml_, respectively. Future mid-
term 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/1 OL 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 non-
potable 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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Appendix E | International Case Studies
Figure 2
Reclaimed water quality monitoring in Tossa de Mar
(Photo credit: Lluis Sala)
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
.
Ministry of Public Health and Consumer Affairs. Technical
Guidelines for the Prevention and Control of Legionellosis in
Facilities. Retrieved on Sept. 7, 2012 from
.
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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 Institute-
Nakornping, 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 Ibs (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 Ib/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
generation is collected daily.
m/day). All waste
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 Ibs (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
riuvv i_t:aviiiy
Digester UASB towards Final Thailand Waste Water
Parameters Influent Aeration Tank Discharge Standard
PH
BOD5 (mg/L)
TCOD
(mg/L)
TKN (mg/L)
TSS (mg/L)
7.1
3,245
1,513
463
812
7.7
86
306
397
150
7.8
327
65
261
59
5.5-9.0
100
400
200
200
TKN = Total Kjehldahl nitrogen (i.e. the combination of organically bound nitrogen and ammonia in
wastewater)
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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 desiqn criteria
Parameter Influent Effluent Design
Criteria
Flow, ML/d
PH
TSS, mg/L
BOD, mg/L
COD, mg/L
NH4-N, mg/L
Total P, mg/L
78
7.2
163
125
301
15.4
2.9
Residual Chlorine, mg/L
Fecal Coliform, #/100 mL
75
7.7
4
2
18
0.2
1.7
85
80
6-9
20
20
-
-
0.01
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.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Figure 1
Average WWTP effluent flow and monthly average
rainfall
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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-own-
operate-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
.
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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 ug/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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Table 1 Water framework directive standards
Parameter
BOD
Ammonia
Suspended Solids
SRP
Total Nitrogen
Dissolved Oxygen (percent saturation)
90 Percentile
>70 %
95 Percentile
10mg/L
2 mg/L
20 mg/L
Maximum
20 mg/L
7mg/L
1,000 ug/L
15 mg/L
>40%
Annual Mean
3.2mg/L
0.28 mg/L
3.1 mg/L
255 ug/L
3.9mg/L
89%
Table 2 Urban wastewater treatment directive (UWWTD) standards
UWWTD limit Annual Average Removal Rate Limit
BOD
COD
Total phosphorus
Total Nitrogen
25mg/L
125 mg/L
1000 ug/L
70-90%
75%
80%
70-80% and 57% by LRP only
LRP Annual Mean Removal
Rate
96%
85%
96%
83% total, 72% by LRP only
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
AJanbakhsh, 2011, Langford Recycling Scheme; 10 year
review, Essex & Suffolk, Water Resources Department.
SJ. 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, AJanbakhsh, SJobling, 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.
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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 (COM 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 AI-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
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 (BAD, 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.
De*a»natton Water
Demand
UAE Water Conservation Strategy, 2010, MOEW
Figure 1
Predicted water supply by sectors in UAE
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Appendix E | International Case Studies
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 (AI-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.
AI-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/Historv 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 Non-
Conventional 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
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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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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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.
Figure 1
Chemical Oxygen Demand (KMnO/i) measured along
the drainage channel in March 2011
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.
2012 Guidelines for Water Reuse
E-121
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Appendix E | International Case Studies
Figure 2
Farmer working in the field in protective clothing
(Photo credit: Lan Huong Nguyen)
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.
2012 Guidelines for Water Reuse
E-122
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Appendix F
Case Studies in 2004 Guidelines for Water Reuse
Section in
2004
Guidelines
2.7.1
2.7.2
2.7.3
2.7.4
2.7.5
2.7.6
2.7.7
2.7.8
2.7.9
2.7.10
2.7.11
2.7.12
2.7.13
2.7.14
2.7.15
2.7.16
2.7.17
2.7.18
2.7.19
3.8.1
3.8.2
3.8.3
5.7.1
5.7.2
5.7.3
5.7.4
5.7.5
5.7.6
5.7.7
5.7.8
U.S. Case Study Title
Water Reuse at Reedy Creek Improvement District
Estimating Potable Water Conserved in Altamonte Springs due to
Reuse
How Using Potable Supplies to Supplement Reclaimed Water Flows
can Increase Conservation
Water Reclamation and Reuse Offer an Integrated Approach to
Wastewater Treatment and Water Resources Issues in Phoenix
Small and Growing Community: Yelm, Washington
Landscape Uses of Reclaimed Water with Elevated Salinity
Use of Reclaimed Water in a Fabric Dyeing Industry
Survey of Power Plants Using Reclaimed Water for Cooling Water
Agricultural Reuse in Tallahassee, Florida
Spray Irrigation at Durbin Creek WWTP Western Carolina Regional
Sewer Authority
Agricultural Irrigation of Vegetable Crops: Monterey, CA
Water Conserv II: City of Orlando and Orange County, FL
The Creation of a Wetlands Park: Petaluma, CA
Geysers Recharge Project: Santa Rosa, CA
Advanced Wastewater Reclamation in California
An Investigation of Soil Aquifer Treatment for Sustainable Water
The City of West Palm Beach, Florida Wetlands-Based Water
Reclamation Project
Types of Reuse Applications in Florida
Regionalizing Reclaimed Water in the Tampa Bay Area
Code of Good Practices for Water Reuse
Examples of Potable Water Separation Standards from the State of
Washington
An Example of using Risk Assessment to Establish Reclaimed Water
Quality Study
Statutory Mandate to Utilize Reclaimed Water: California
Administrative Order to Evaluate Feasibility of Water Reclamation:
Fallbrook Sanitary District, Fallbrook, CA
Reclaimed Water User Agreements Instead of Ordinance: Central
Florida
Interagency Agreement Required for Water Reuse: Monterey County
Water Recycling Project, Monterey, CA
Public/Private Partnership to Expand Reuse Program: The City Of
Orlando, Orange County and The Private Sector
Inspection of Reclaimed Water Connections Protect Potable Water
Supply: Pinellas County Utilities, Florida
Oneida Indian Nation/Municipal/State Coordination Leads to Effluent
Reuse: Oneida Nation, New York
Implementing Massachusetts' First Golf Course Irrigation System
Utilizing Reclaimed Water: Yarmouth, MA
Orlando
Altamonte Springs
Hillsborough County
Phoenix
Yelm
El Paso
Santa Fe Springs
Multiple
Tallahassee
Fountain Inn
Monterey
Orange County
Petaluma
Santa Rosa
Orange County
6 sites
West Palm Beach
Statewide
Tampa Bay FL
Statewide
Statewide
Statewide
Fallbrook
Orlando
Monterey
Orlando
Pinellas County
Oneida
Yarmouth
FL
FL
FL
AZ
WA
TX
CA
US
FL
SC
CA
FL
CA
CA
CA
AZ/CA
FL
FL
FL
WA
US
CA
CA
FL
CA
FL
FL
NY
MA
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
6.7.1
6.7.2
6.7.3
6.7.4
6.7.5
6.7.6
6.7.7
7.5.1
7.5.2
7.5.3.1
7.5.3.2
7.5.4
7.5.5
7.5.6
7.5.7
Unique Funding Aspects of the Town of Longboat Key Reclaimed
Water System
Financial Assistance in San Diego County, California
Grant Funding Through the Southwest Florida Water Management
District
Use of Reclaimed Water to Augment Potable Supplies: An Economic
Perspective (California)
Impact Fee Development Considerations for Reclaimed Water
Projects: Hillsborough County, FL
How Much Does it Cost and Who Pays: A Look at Florida's Reclaimed
Water Rates
Rate Setting for Industrial Reuse in San Marcos, TX
Accepting Produce Grown with Reclaimed Water: Monterey, California
Water Independence in Cape Coral - An Implementation Update in
2003
Learning Important Lessons-San Diego, California
Public Outreach May not be Enough: Tampa, FL
Pinellas County, Florida Adds Reclaimed Water to Three R's of
Education
Yelm, Washington, A Reclaimed Water Success Story
Gwinnett County, Georgia - Master Plan Update Authored by Public
AWWA Golf Course Reclaimed Water Market Assessment
Longboat Key
San Diego
SW Florida
LA/Orange Co.
Hillsborough County
Statewide
San Marcos
Monterey
Cape Coral
San Diego
Tampa
Pinellas County
Yelm
Gwinnett County
FL
CA
FL
CA
FL
FL
TX
CA
FL
CA
FL
FL
WA
GA
National U.S.
Section in
2004
Guidelines
8.5.1
International Case Study by Country
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
F-2
2012 Guidelines for Water Reuse
-------
Appendix F | Case Studies in 2004 Guidelines for Water Reuse
Section in
2004
Guidelines
8.5.17
International Case Study by Country
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 I'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
2012 Guidelines for Water Reuse
F-3
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Appendix F | Case Studies in 2004 Guidelines for Water Reuse
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F-4 2012 Guidelines for Water Reuse
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APPENDIX G
Abbreviations
Abbreviations for Names of States
Full Name
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
District of Columbia
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Text Abbreviation
Ala.
Alaska
Ariz.
Ark.
Calif.
Colo.
Conn.
Del.
D.C.
Fla.
Ga.
Hawaii
Idaho
III.
Ind.
Iowa
Kan.
Ky.
La.
Maine
Md.
Mass.
Mich.
Minn.
Miss.
Mo.
Mont.
Neb.
Nev.
N.H.
NJ.
N.M.
N.Y.
N.C.
N.D.
Ohio
Okla.
Ore.
Pa.
R.I.
S.C.
S.D.
Tenn.
Texas
Utah
Vt.
Va.
Wash.
W. Va.
Wis.
Wyo.
Case Study Abbreviation
AL
AK
AZ
AR
CA
CO
CT
DE
DC
FL
GA
HI
ID
IL
IN
IA
KS
KY
LA
ME
MD
MA
Ml
MN
MS
MO
MT
NE
NV
NH
NJ
NM
NY
NC
ND
OH
OK
OR
PA
Rl
SC
SD
TN
TX
UT
VT
VA
WA
WV
Wl
WY
2012 Guidelines for Water Reuse
G-1
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Appendix G | Abbreviations
Abbreviations for Units of Measure
Abbreviation Unit
ac
ac-ft
ac-ft/yr
bbl/yr
BTU
cfu
cm
m3
m3/d
d
°C
°F
ft
gallon
GJ
gpd
gpcd
gpm
g
ha
hp
hr
ccf
in
J
kg
kg/ha
km
kPa
kW
kWh
L
Lpcd
L/s
MW
MWhr
Acre
Acre-foot
Acre-foot per year
Barrels per year
British thermal unit
Colony forming units
Centimeter
Cubic meter
Cubic meters per day
Day
Degrees Celsius
Degrees Fahrenheit
Foot (feet)
Gallon
Gigajoules
Gallons per day
Gallons per capita per day
Gallons per minute
Gram
Hectare
Horsepower
Hour
Hundred cubic feet
Inch
Joules
Kilogram (103 g)
Kilogram per hectare
Kilometer (103 m)
Kilopascal(103Pa)
Kilowatt (103W)
Kilowatt hour
Liter
Liters per capita per day
Liters per second
Megawatt (1 06 W)
Megawatt hours
Abbreviation Unit
m
m/s
pg
pg/L
MCM
MCM/yr
mgd
urn
mi
mph
mg
mg/L
mL
mm
meq/L
MAFY
min
MPN
nm
NTU
ppt
Pa
pfu
Ib
Ib/ac
psi
s
ft2
in2
km2
m2
mi2
TWh/yr
W
yr
Meter
Meters per second
Microgram (106 g)
Micrograms per liter
Million cubic meters
Million cubic meters per
Million (106) gallons per
year
day
Micrometer (106 m)
Mile
Miles per hour
Milligram (103 g)
Milligrams per liter
Milliliter(103l)
Millimeter (103 m)
Milliequivalent per liter
Million acre feet per year
Minute
Most probable number
Nanometer (109 m)
Nephelometric turbidity
units
Parts per trillion
Pascal
Plaque forming unit
Pound
Pounds per acre
Pounds per square inch
Second
Square foot
Square inch
Square kilometers
Square meter
Square mile
TWh/yr
Watt
Year
G-2
-------
United States
Environmental Protection
Agency
Office of Research and Development
National Risk Management
Research Laboratory
Cincinnati, OH 45268
FROM THE AMERICAN PEOPLE
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