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.

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.

Direct potable reuse: a future imperative

International Water Association (IWA) Publishing | March 1st, 2011

As a result of population growth, urbanization, and climate change, public water supplies are becoming stressed, and the chances of tapping new water supplies for

As a result of population growth, urbanization, and climate change, public water supplies are becoming stressed, and the chances of tapping new water supplies for metropolitan areas are getting more difficult, if not impossible. As a consequence, existing water supplies must go further. One way to achieve this objective is by increased water reuse, particularly in supplementing municipal water supplies. Although water reuse offers many opportunities it also involves a number of problems. A significant cost for nonpotable water reuse in urban areas is associated with the need to provide separate piping and storage systems for reclaimed water. In most situations, the cost of a dual distribution system has been prohibitive and thus, has limited implementation for water reuse programs. The solution to the problem of distribution is to implement direct potable reuse (DPR) of purified water in the existing water distribution system. The purpose of this paper is to consider (a) a future in which DPR will be the norm and (b) the steps that will need to be taken to make this a reality. Following an overview, the rationale for DPR, some examples of DPR projects, technological and implementation issues, and future expectations are examined.

Distributions of waterborne pathogens in raw wastewater based on a 14-month, multi-site monitoring campaign

Water Research | February 9th, 2022

The California State Water Resources Control Board is the first regulatory body in the United States to develop statewide regulations for direct potable reuse (DPR). To s

The California State Water Resources Control Board is the first regulatory body in the United States to develop statewide regulations for direct potable reuse (DPR). To support this effort, a pathogen monitoring campaign was undertaken to develop and implement an optimized standard operating protocol to better characterize the concentration of human pathogens in raw wastewater. Methods to detect relevant viral and protozoan pathogens in raw wastewater were optimized and implemented during a 14-month monitoring campaign. Over 120 samples were collected from five wastewater treatment plants treating a quarter of California's population. Samples were analyzed for two protozoa (Cryptosporidium and Giardia) using microscopy methods, three enteric viruses (enterovirus, adenovirus, and norovirus) using culture and/or molecular methods, and male-specific coliphage using culture methods. The method recovery efficiency was measured in every protozoa sample and every other virus sample to confirm minimum recovery efficiencies were achieved and to correct the concentrations for pathogen losses during sample processing. The results from this study provide the industry with a large, high-quality dataset as demonstrated by the high degree of method sensitivity, method recovery, and QA/QC steps. Such high-quality data on pathogen concentrations in raw wastewater are critical for confirming the level of treatment needed to reduce pathogen concentrations down to acceptable levels for potable water in DPR projects.

From wastewater treatment plants to decentralized resource factories

Nature Portfolio (Springer Nature) | June 10th, 2024

Investigation on the Feasibility of Developing Uniform Water Recycling Criteria for Direct Potable Reuse

California State Water Resources Control Board (SWRCB) | December 29th, 2016

In 2010, the California Legislature enacted Senate Bill (SB) 918 (Chapter 700, Statutes of 2010), which added sections 13560-13569 (Division 7, Chapter 7.3) to the Water

In 2010, the California Legislature enacted Senate Bill (SB) 918 (Chapter 700, Statutes of 2010), which added sections 13560-13569 (Division 7, Chapter 7.3) to the Water Code regarding potable reuse of recycled water. SB 918 defined the term “direct potable reuse”1 and directed the California Department of Public Health (CDPH) to investigate the feasibility of developing uniform water recycling criteria for direct potable reuse (DPR), convene an expert panel to study the technical and scientific issues, and provide a final report to the Legislature by December 31, 2016. The main difference between DPR and indirect potable reuse (IPR) is DPR’s lack of a meaningful environmental buffer. In 2013, the Legislature enacted SB 322 (Chapter 637, Statutes of 2013), which amended Chapter 7.3 of the Water Code to require that an advisory group subject to the Bagley-Keene Open Meeting Act be convened to advise the expert panel and the State Water Board in the development of the feasibility report. SB 322 additionally tasked the expert panel to assess whether additional areas of research are needed to be able to establish uniform regulatory criteria for DPR and to recommend an approach for accomplishing any additional needed research in a timely manner. SB322 required that a draft report summarizing the expert panel research recommendations be prepared by June 30, 2016, and a draft feasibility report be provided to the public for comment by September 1, 2016.

Investigation on the Feasibility of Developing Uniformwater Recycling Criteria ror Direct Potable Reuse

California State Water Resources Control Board (SWRCB) | December 1st, 2016

The population of California is projected to increase from 38 million to 50 million by the year 2049. This population increase will have a dramatic impact on the water ne

The population of California is projected to increase from 38 million to 50 million by the year 2049. This population increase will have a dramatic impact on the water needs of the State. To address this increased water need, the State will take a variety of actions as outlined in the Governor’s California Water Action Plan, first released in 2014 and recently updated in 2016 (CA Natural Resources Agency, 2016). One component of that plan is to increase the use of recycled water. The State Water Board has set a mandate of increasing the use of recycled water by 200,000 acre-foot per year (AFY) by 2020 and an additional 300,000 AFY by 2030. Although the use of recycled water for non-potable uses such as agricultural and landscape irrigation is already well established and has been regulated for decades in California, increasing the use of recycled water for both non-potable uses as well as a source of potable water (“potable reuse”) is important for the State to be able to meet this mandate. For example, groundwater replenishment (groundwater recharge), which is an indirect form of potable reuse, has the capacity to reuse 200,000 acre-feet of recycled water a year via just eight projects throughout California. Accordingly, the State Water Board revised and adopted uniform water recycling criteria for groundwater replenishment in 2014 and is in the process of establishing uniform water recycling criteria for the augmentation of surface water reservoirs used as a source of drinking water supply, which is another form of indirect potable reuse.

One Water LA 2040 Plan

City of Los Angeles | April 30th, 2018

The purpose of the One Water LA 2040 Plan (Plan) is to increase sustainable water management for the City of Los Angeles (City). The City launched One Water LA with two p

The purpose of the One Water LA 2040 Plan (Plan) is to increase sustainable water management for the City of Los Angeles (City). The City launched One Water LA with two primary goals: 1. Develop a vision and implementation strategy to more sustainably and cost-effectively manage water. 2. Identify ways for City departments and regional agencies to integrate their water management strategies. Los Angeles Sanitation (LASAN) and the Los Angeles Department of Water and Power (LADWP) led the Plan's development, partnering with other City departments, regional agencies, academia, the business community, and other stakeholders. The Plan provides a comprehensive strategy for managing water in a more integrated, collaborative, and sustainable way through new project, program, and policy opportunities. The Implementation Strategy provides a roadmap to make the One Water LA Vision a reality. Additional water projects, programs, or policies that are the sole responsibility of one agency, including LADWP's aqueduct or groundwater remediation project, are contained in each agency's appropriate plans. This plan is divided into an Executive Summary and ten sections. Executive Summary Volume One: Summary Report Volume Two: Wastewater Facilities Plan Volume Three: Stormwater and Urban Runoff Facilities Plan Volume Four: Los Angeles River Flow Study Volume Five: Integration Opportunities Analysis Volume Six: Climate Risk and Resilience Assessment for Wastewater and Stormwater Infrastructure Volume Seven: Implementation Strategy Supporting Documents Volume Eight: Technical Support Materials Volume Nine: Stakeholder Engagement Materials, Part 1, Part 2, Part 3 Volume Ten: Programmatic Environmental Impact Report (in progress)

Potable Reuse 101: An innovative and sustainable water supply solution

American Water Works Association (AWWA) | April 14th, 2016

Both the quality and quantity of conventional water supplies are increasingly affected by population growth, urbanization, prolonged and severe droughts, and climate chan

Both the quality and quantity of conventional water supplies are increasingly affected by population growth, urbanization, prolonged and severe droughts, and climate change. Consequently, finding the opportunities to develop new groundwater or surface water sources is becoming more challenging. With an increased pressure on water systems, a diversified portfolio of water sources is required to meet future water demands, ensure public health, and provide economic and environmental sustainability. Many communities are working to increase water conservation and seek new strategies to develop sustainable water supplies for the future. For that reason, there is a clear need to use our existing local water resources effectively to produce and provide reliable, high-quality water. One viable approach to address existing and anticipated water shortages is to implement water reuse in which used water from homes and businesses is highly treated and used to augment public water supplies.

The frontiers of water and sanitation

Nature Portfolio (Springer Nature) | January 19th, 2023

The way in which human society uses water is continuously evolving. The present challenges related to clean water availability require the development of sustainable tech

The way in which human society uses water is continuously evolving. The present challenges related to clean water availability require the development of sustainable technologies and infrastructure. Furthermore, a stronger and wider appreciation of water inequalities and injustice demand an adequate transformation of water governance at local and global scale. We have asked nine experts in various sectors of water-related research to share their views on how water and sanitation science, technology and governance must evolve to meet the requirements of a healthier relationship between water and society.