Date:  Jan. 10, 2012




Reuse of Municipal Wastewater Has Significant Potential to Augment Future U.S. Drinking Water Supplies


WASHINGTON — With recent advances in technology and design, treating municipal wastewater and reusing it for drinking water, irrigation, industry, and other applications could significantly increase the nation's total available water resources, particularly in coastal areas facing water shortages, says a new report from the National Research Council.  It adds that the reuse of treated wastewater, also known as reclaimed water, to augment drinking water supplies has significant potential for helping meet future needs.  Moreover, new analyses suggest that the possible health risks of exposure to chemical contaminants and disease-causing microbes from wastewater reuse do not exceed, and in some cases may be significantly lower than, the risks of existing water supplies. 


"Wastewater reuse is poised to become a legitimate part of the nation's water supply portfolio given recent improvements to treatment processes," said R. Rhodes Trussell, chair of the committee that wrote the report and president of Trussell Technologies, Pasadena, Calif.  "Although reuse is not a panacea, wastewater discharged to the environment is of such quantity that it could measurably complement water from other sources and management strategies."


The report examines a wide range of reuse applications, including potable water, non-potable urban and industrial uses, irrigation, groundwater recharge, and ecological enhancement.  The committee found that many communities have already implemented water reuse projects -- such as irrigating golf courses and parks or providing industrial cooling water in locations near wastewater reclamation plants -- that are well-established and generally accepted.  Potable water reuse projects account for only a small fraction of the volume of water currently being reused.  However, many drinking water treatment plants draw water from a source that contains wastewater discharged by a community located upstream; this practice is not officially acknowledged as potable reuse.    


The report outlines wastewater treatment technologies for mitigating chemical and microbial contaminants, including both engineered and natural treatment systems.  These processes can be used to tailor wastewater reclamation plants to meet the quality requirements of intended reuse applications.  The concentrations of chemicals and microbial contaminants in reuse projects designed to augment drinking water supplies can be comparable to or lower than those commonly present in many drinking water supplies.  The committee emphasized the need for process reliability and careful monitoring to ensure that all reclaimed water meets the appropriate quality objectives for its use.


Costs of water reuse for potable and non-potable applications vary widely because they depend on site-specific factors, the committee said.  Water reuse projects tend to be more expensive than most water conservation options and less expensive than seawater desalination and other new supply alternatives.  Although the costs of reclaimed water are often higher than current water sources, the report urges water authorities to consider other costs and benefits in addition to monetary expenditures when assessing reuse projects.  For example, water reuse systems used in conjunction with a water conservation program could be effective in reducing seasonal peak demands on the drinking water system.  Depending on the specific designs and pumping requirements, reuse projects could also have a larger or smaller carbon footprint than existing supply alternatives or reduce water flows to downstream users and ecosystems.   


Water reuse regulations differ by state and are not based on risk-assessment methods, the report says.  Adjustments to the federal regulatory framework could help ensure a high level of public health protection, provide a consistent minimum level of protection across the nation, and increase public confidence in potable and non-potable water reuse.  The report notes that existing legislative tools could be applied to improve the quality of water for reuse, including updating the National Pretreatment Program's list of priority pollutants to include a wider inventory of known toxic substances.  Also, it lists 14 areas of research to help guide the country on how to apply water reuse appropriately.  Such research would require improved coordination among federal and nongovernmental organizations.


The study was sponsored by the U.S. Environmental Protection Agency, U.S. Bureau of Reclamation, National Science Foundation, National Water Research Institute, Centers for Disease Control and Prevention, Water Research Foundation, Orange County Water District, Orange County Sanitation District, Los Angeles Department of Water and Power, Irvine Ranch Water District, West Basin Water District, Inland Empire Utilities Agency, Metropolitan Water District of Southern California, Los Angeles County Sanitation Districts, and Monterey Regional Water Pollution Control Agency. 


The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies.  They are independent, nonprofit institutions that provide science, technology, and health policy advice under an 1863 congressional charter.  Panel members, who serve pro bono as volunteers, are chosen by the Academies for each study based on their expertise and experience and must satisfy the Academies' conflict-of-interest standards.  The resulting consensus reports undergo external peer review before completion.  For more information, visit  A panel roster follows.




Jennifer Walsh, Media Relations Officer

Luwam Yeibio, Media Relations Assistant

Office of News and Public Information

202-334-2138; e-mail


Pre-publication copies of Water Reuse: Potential for Expanding the Nation’s Water Supply Through Reuse of Municipal Wastewater are available from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or on the Internet at  Reporters may obtain a copy from the Office of News and Public Information (contacts listed above).

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Division on Earth and Life Studies

Water Science and Technology Board


Committee to Assess Water Reuse as an Approach for Meeting Future Water Supply Needs


R. Rhodes Trussell* (chair)


Trussell Technologies Inc.

Pasadena, Calif.


Henry A. Anderson

Chief Medical Officer for Occupational and Environmental Health

Wisconsin Division of Public Health



Edmund Archuleta

President and CEO

El Paso Water Utilities Public Service Board

El Paso, Texas


James Crook

Professional Engineer and Independent Consultant

Monterey Regional Water Pollution Control Agency

Monterey, Calif.


Jorg E. Drewes

Professor of Civil and Environmental Engineering

Colorado School of Mines



Denise D. Fort


School of Law

University of New Mexico



Charles N. Haas

Betz Professor of Environmental Engineering

Department of Civil, Architectural, and Environmental Engineering

Drexel University



Brent Haddad

Professor of Environmental Studies, and

Founder and Director

Center for Integrated Water Research

University of California

Santa Cruz


Duane Huggett

Assistant Professor

Department of Biology

Institute of Applied Sciences

University of North Texas



Sunny Jiang

Associate Professor of Environmental Engineering, Environmental Health, and Environmental Toxicology

University of California



David L. Sedlak

Professor of Civil and Environmental Engineering

University of California



Shane Snyder


College of Engineering

University of Arizona



Margaret H. Whittaker

Chief Toxicologist


Washington, D.C.


Dale Whittington


Departments of Environmental Sciences and Engineering and City and Regional Planning

University of North Carolina

Chapel Hill




Stephanie Johnson

Study Director


 * Member, National Academy of Engineering