2017 Potable Reuse Compendium

U.S. Environmental Protection Agency (EPA) | January 11th, 2018

Appropriate and necessary treatment and reuse of wastewater to augment existing water resources is a rapidly expanding approach for both non-potable and potable

Appropriate and necessary treatment and reuse of wastewater to augment existing water resources is a rapidly expanding approach for both non-potable and potable applications. EPA recognizes that potable reuse of water can play a critical role in helping states, tribes, and c ommunities meet their future drinking water needs with a diversified portfolio of water sources. Beginning with the first pioneers in water reuse, Los Angeles County Sanitation Distric t (1962), Orange County Sanitation District (1976), and the Upper Occoquan Service Authority (1978), the practice has gained substantial momentum because of drought and the need to assure groundwater resource sustainability and a secure water supply. Long-term water scarcity is expected to increase over time in many parts of the country as a result of drought, growing water demand, and other stressors. Across the U.S., there has been a notable increase in the deployment of technologies to augment existing water supplies through reuse of wastewater that has been treated and cleaned to be safe for the intended use. Indirect reuse usually involves passage of water through an environmental buffer (e.g., groundwater aquifer, lake, river) before the water is again treated for reuse. Direct reuse refers to those situations where treatment is followed by storage and use, but without the environmental buffer. Many drinking water systems rely on water treatment technologies to support indirect reuse of water (e.g., indirect potable reuse) and some drinking water systems now directly reuse wastewater after treatment (e.g., direc t potable reuse). In 2012, EPA published the 2012 Guidelines for Water Reuse to serve as a reference on water reuse practices . The document provided information related to indirect potable reuse (IPR), but only briefly described direc t potable reuse (DPR). Because of increased interest in pursuing potable water reuse, EPA is is suing the 2017 Potable Reuse Compendium to outline key science, technical, and policy considerations regarding this practice. This 2017 Compendium supplements the 2012 Guidelines for Water Reuse to inform current practices and approaches in potable reuse, including those related to direct potable water reuse. EPA recognizes the recent water reuse publications from our stakeholders at the World Health Organization (WHO), the National Research Council of the National Academies of Science, the Water Environment and Reuse Foundation (WE&RF), and the Water Environment Federation (WEF). The 2017 Compendium is a compilation of technical information on potable reuse practices to provide planners and decision-makers with a summary of the current state of the practice. Specific knowledge and experience are drawn from case studies on existing reuse approaches. EPA supports water reuse as part of an integrated water resources management approach developed at the state and local level to meet the water needs of multiple sectors including agriculture, industry, drinking water, and ecosystem protection. An integrated approach commonly involves a combination of water management strategies (e.g., water supply development, water storage, water use efficiency, and water reuse) and engages multiple stakeholders and needs, including the needs of the environment. Although EPA encourages an integrated approach to water resources management, it does not require or restrict practices such as water reuse. EPA acknowledges the primacy of states in the allocation and development of water resources. EPA, State, and local governments implement programs under the Clean Water Act and the Safe Drinking Water Act to protect the quality of source waters to ensure that source water is treated so that water provided to the tap is safe for people to drink (e.g., contaminant specific drinking water standards). The SDWA and the CWA provide a foundation from which states can further develop and support potable water reuse as they deem appropriate. EPA will continue to engage a broad spectrum of partners and stakeholders for input on where the Agency can provide meaningful support to states, tribes, and communities as they implement potable water reuse projects. EPA will also work with stakeholders, the scientific community , and the States to monitor and evaluate performance of water treatment technologies to ensure that potable reuse projects are implemented in a manner that protects the health of communities . This document is a collaborative effort between EPA, CDM Smith, and other key stakeholders. EPA acknowledges the importance of potable water reuse and looks forward to working with our stakeholders as the practice continues to be developed and deployed as an important approach to ensure a c lean, safe, and sustainable water supply for the nation.

A changing framework for urban water systems

American Chemical Society (ACS) | May 8th, 2013

Urban water infrastructure and the institutions responsible for its management have gradually evolved over the past two centuries. Today, they are under increas

Urban water infrastructure and the institutions responsible for its management have gradually evolved over the past two centuries. Today, they are under increasing stress as water scarcity and a growing recognition of the importance of factors other than the cost of service provision are forcing a reexamination of long-held ideas. Research and development that supports new technological approaches and more effective management strategies are needed to ensure that the emerging framework for urban water systems will meet future societal needs

A Synthesis of Aquatic Science for Management of Lakes Mead and Mohave

U.S. Geological Survey (USGS) | January 29th, 2013

Lakes Mead and Mohave, which are the centerpieces of Lake Mead National Recreation Area, provide many significant benefits that have made the modern development of the So

Lakes Mead and Mohave, which are the centerpieces of Lake Mead National Recreation Area, provide many significant benefits that have made the modern development of the Southwestern United States possible. Lake Mead is the largest reservoir by volume in the nation and it supplies critical storage of water supplies for more than 25 million people in three Western States (California, Arizona, and Nevada). Storage within Lake Mead supplies drinking water and the hydropower to provide electricity for major cities including Las Vegas, Phoenix, Los Angeles, Tucson, and San Diego, and irrigation of more than 2.5 million acres of croplands. Lake Mead is arguably the most important reservoir in the nation because of its size and the services it delivers to the Western United States. This Circular includes seven chapters. Chapter 1 provides a short summary of the overall findings and management implications for Lakes Mead and Mohave that can be used to guide the reader through the rest of the Circular. Chapter 2 introduces the environmental setting and characteristics of Lakes Mead and Mohave and provides a brief management context of the lakes within the Colorado River system as well as overviews of the geological bedrock and sediment accumulations of the lakes. Chapter 3 contains summaries of the operational and hydrologic characteristics of Lakes Mead and Mohave. Chapter 4 provides information on water quality, including discussion on the monitoring of contaminants and sediments within the reservoirs. Chapter 5 describes aquatic biota and wildlife, including food-web dynamics, plankton, invertebrates, fish, aquatic birds, and aquatic vegetation. Chapter 6 outlines threats and stressors to the health of Lake Mead aquatic ecosystems that include a range of environmental contaminants, invasive species, and climate change. Chapter 7 provides a more detailed summary of overall findings that are presented in Chapter 1; and it contains a more detailed discussion on associated management implications, additional research, and monitoring needs.

Adapting to Change: Utility Systems and Declining Flows

California Urban Water Agencies (CUWA) | November 1st, 2017

During the recent historic drought, Californians responded to the call for emergency statewide water use reductions, which the state has recognized as a highly su

During the recent historic drought, Californians responded to the call for emergency statewide water use reductions, which the state has recognized as a highly successful outcome. However, this significant reduction in water demands has brought to light some unintended consequences of declining flows that ripple throughout the interconnected urban water cycle. These observations offer a preview into the potential impact of establishing permanent indoor water use targets at or below the thresholds achieved as a result of the governor’s emergency conservation mandate. California’s water industry leaders, including regulators and purveyors, are working to understand the system-wide impacts of increased conservation so that decision makers are better informed as they address California’s current and future water challenges. Through a partnership with California Association of Sanitation Agencies (CASA), Water Research Foundation(WRF), WateReuse California, and California Water Environment Association(CWEA), California WaterUrban Agencies(CUWA) has developed this white paper to provide decisionmakers, water/wastewater system managers, and other stakeholders an understanding of the impacts of declining flows resulting from substantial reductions in indoor water use and how utilities are adapting to these circumstances.

Adapting wastewater management systems in California for water conservation and climate change

Sustainable and Resilient Infrastructure (Taylor & Francis) | February 27th, 2023

Addressing Impediments and Incentives for Agricultural Reuse

Water Research Foundation | December 6th, 2023

Water systems across the United States are facing unprecedented levels of stress arising from challenges such as a changing climate, aging infrastructure, and shifting pa

Water systems across the United States are facing unprecedented levels of stress arising from challenges such as a changing climate, aging infrastructure, and shifting patterns of water supply and demand. Agricultural water reuse has the potential to increase the resilience of water and agricultural systems through benefits such as supply diversification, access to an additional water supply, nutrient management, and compliance with water quality permits. However, realization of these benefits and scaling reuse are hindered by broad ranging, but surmountable barriers and tradeoffs. Part 1 of this report (Literature Review) provides a synthesis of the health and agronomic risks of agricultural water reuse in the context of current regulatory frameworks. Part 2 of this report (Guidebook) highlights specific strategies for addressing barriers to agricultural water reuse and includes thirteen profiles of projects and programs advancing agricultural water reuse. This work (WRF 4956) directly builds on the lessons learned in WRF 4775, Agricultural Use of Recycled Water: Impediments and Incentives, (Sheikh et al. 2019) and WRF 4829, Economic and Environmental Benefits of Agricultural Water Reuse (Thebo 2021). While the specific drivers and challenges of agricultural water reuse projects vary widely across contexts, several common themes emerged in this work. The most successful agricultural water reuse projects invariably address multiple objectives and deliver co-benefits to diverse stakeholders. They do this through early, ongoing, and strategic stakeholder engagement and partnerships. State and federal agencies can support advancement of agricultural water reuse through robust capacity building programs and integration of co-benefits into funding programs. Science-based regulatory programs that are aligned with the needs of both water agencies and the agricultural sector can streamline permitting processes while remaining protective of human, agronomic, and environmental health. In combination, the research products developed in WRF 4956 aim to support water managers, regulators, and the agricultural sector in identifying and overcoming barriers to agricultural water reuse across diverse geographic and agricultural contexts in the United States.

Annual Report Clean Water State Revolving Fund and the Water Quality, Supply, and Infrastructure Improvement Act of 2014 State Fiscal Year 2017-2018

California State Water Resources Control Board (SWRCB) | December 30th, 2018

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annua

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annual report for State Fiscal Year (SFY) 2017-18. The State Water Board provided approximately $707 million in new CWSRF financing to 44 projects in SFY 2017-18, which represent a wide variety of projects eligible under the CWSRF. This report describes how the State Water Board met the objectives identified in the SFY 2017-18 CWSRF Intended Use Plan (IUP). 

Bottoms Up: Treated sewage could be the safest, most environmentally sound source of tap water yet - if we can get over the yuck factor

Scientific American | July 1st, 2014

On a sunny day in December, I visit a shiny, sterile water-processing facility nestled in the hills of northern San Diego. Sheltered by an ugly cream-colored roof but l

On a sunny day in December, I visit a shiny, sterile water-processing facility nestled in the hills of northern San Diego. Sheltered by an ugly cream-colored roof but lacking walls, the workings of this oversize chemist’s laboratory glisten in the warm winter sun. Visible from every angle are row on row of silver tubes and canisters of various shapes and sizes and great gray metal vats of concealed liquid. As my tour of the small plant comes to a close, I am presented with a challenge: to identify, by sight, the contents of three large glass bottles, spaced evenly on a table before me and filled with clear fluids. The first bottle seems to have a slight yellow hue. The second is colorless. The third has the brilliance of a well-cut diamond.

Contributions of recycled wastewater to clean water and sanitation Sustainable Development Goals

Clean Water | April 30th, 2020

Water resources are essential for every development activity, not only in terms of available quantity but also in terms of quality. Population growth and urbani

Water resources are essential for every development activity, not only in terms of available quantity but also in terms of quality. Population growth and urbanisation are increasing the number of users and uses of water, making water resources scarcer and more polluted. Changes in rainfall patterns threaten to worsen these effects in many areas. Water scarcity, due to physical lack or pollution, has become one of the most pressing issues globally, a matter of human, economic and environmental insecurity. Wastewater, whose value had not been appreciated until recently, is increasingly recognised as a potential ‘new’ source of clean water for potable and non-potable uses, resulting in social, environmental and economic benefits. This paper discusses the potential of recycled wastewater (also known as reused water) to become a significant source of safe water for drinking purposes and improved sanitation in support of the Sustainable Development Goals.

Critical Review: Regulatory Incentives and Impediments for onsite Graywater Reuse in the United States

Water Environment Research | July 11th, 2013

Graywater is a potential water source for reducing water demand. Accordingly, a review was undertaken of graywater reuse regulations and guidelines within the 50 United

Graywater is a potential water source for reducing water demand. Accordingly, a review was undertaken of graywater reuse regulations and guidelines within the 50 United States. Major issues considered included acceptability for graywater segregation as a separate wastewater stream, allowable graywater storage, onsite treatment requirements, and permitted graywater use applications. Existing regulations and plumbing codes in the different states suggest that there are impediments to overcome but also potential incentives for graywater reuse. It is encouraging that regulations in 29 states promote safe graywater reuse, but there are also inconsistencies between plumbing codes and other regulations within and among the 50 states. Impediments to graywater reuse include disallowances of graywater segregation or collection, and restriction of graywater reuse to mostly subsurface irrigation with limited indoor use permission. Ease on restrictions and guidelines to promote development of low-cost and proven treatment technologies are needed to promote graywater reuse.