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Direct Potable Reuse


This section includes information and resources about direct potable reuse (DPR), which involves the planned introduction of recycled water either directly into a public water system or into a raw water supply upstream of a water treatment plant.


Water researchers and practitioners are interested in DPR because it can be used to augment current drinking water supplies (such as surface water, groundwater, or imported water) with a local, abundant, and reliable source of water.


For information about water reuse in general, click here.



Guidance Framework for Direct Potable Reuse in Arizona

The WateReuse Arizona, AZ Water Association, and National Water Research Institute (NWRI) collaborated on the publication of Guidance Framework for Direct Potable Reuse in Arizona, meant to inform the State of Arizona as it develops regulations for direct potable reuse (DPR) that are protective of public health. The report was released in January 2018.


Download the report here (PDF).



Potable Reuse Research Compilation: Synthesis of Findings 

The purpose of this report is to summarize and synthesize key issues and findings related to research involving the technical feasibility of implementing direct potable reuse (DPR) projects.  The report aims to provide a clear and comprehensive understanding of the state-of-the-art and state-of-thescience on DPR and to identify unknowns that may require further research. The topics addressed in this report include: source control, treatment trains, surrogates and log reduction credits for pathogens, pathogen monitoring, constituents of emerging concern, critical control points to monitor DPR systems, operation and maintenance of DPR facilities, operator training and certification, the resilience of DPR systems, and reliable and redundant treatment train performance.

Click here to download the report (1.99-MB PDF).

Recommended DPR General Guidelines and Operational Requirements for New Mexico

On behalf of the New Mexico Environment Department (NMED), NWRI administered an Independent Advisory Panel to develop proposed and general direct potable reuse (DPR) guidelines and operational requirements for the State of New Mexico that are protective of public health. The final report includes the panel’s recommendations to NMED regarding the following topics: Water Quality; Source Control; Enhanced Wastewater Treatment Advanced Water Treatment Technologies; Process Control and Monitoring; Operation and Maintenance; Technical, Managerial, and Financial Capacity; Public Acceptance and Outreach; and Small Water System Considerations.


Download the report here (0.7 MB PDF).


Framework for Direct Potable Reuse (2015)


Download report
(4-MB PDF)

A first-of-its-kind guidance document, Framework for Direct Potable Reuse, was released on Sept 14, 2015,  to help state regulatory agencies and utilities develop guidelines for safely converting wastewater into municipal drinking water through the emerging practice of DPR.  It was sponsored by the WateReuse Association and co-sponsored by NWRI, American Water Works Association, and Water Environment Federation.


DPR involves the use of state-of-the art advanced water treatment technologies to remove contaminants in wastewater; however, current state and federal regulations were not developed with today’s technologies in mind.  Until guidelines and regulations are prepared, this framework document can serve as a valuable resource to municipalities, utilities, and agencies interested in implementing DPR programs to augment community water supplies.
An NWRI Independent Advisory Panel made up of seven experts prepareed the document.  Their backgrounds include water and wastewater treatment, water quality policy and regulations, water resource planning, and public health risk assessment. Additional information can be found at the WateReuse website


NWRI White Paper on "Direct Potable Reuse: Benefits for Public Water Supplies, Agriculture, the Environment, and Energy Conservation"

By Edward Schroeder, University of California, Davis, et al.

This 20-page NWRI White Paper (2012) focuses on the role that direct potable reuse (DPR) can have in the management of water resources in the future. Using a case study based on Southern California, the authors point out that the potential benefits accrued for agriculture, environmental preservation and enhancement, and energy conservation through the application of DPR may be more important than its ability to provide an alternative water supply. Click here to download the white paper.

WateReuse Report on “Direct Potable Reuse: A Path Forward”

By George Tchobanoglous, University of California, Davis, et al.

This 102-page report identifies the information and research needed to provide a basis for the feasibly of implementing direct potable reuse (DPR) in California. Topics discussed include issues regarding public acceptance, engineering, economics, and regulations. WateReuse Research Foundation and WateReuse California published this report in 2011.  Click here to download the report.

Direct Potable Reuse Workshop: Workshop Report

This 41-page report was prepared by California Urban Water Agencies, National Water Research Institute, and WateReuse California to summarize the results of a workshop held on April 26-27, 2010, for the purpose of identifying information gaps and existing barriers that need to be addressed to develop direct potable reuse regulations in California. Information gathered from this workshop is expected to help support the needs of water, wastewater, and recycled water agencies in long-term planning and in prioritizing research-related activities.  To download the workshop report, click here.

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NWRI White Paper on "Regulatory Aspects of Direct Potable Reuse in California"

By James Crook, Ph.D., P.E., Environmental Engineering Consultant

This 32-page White Paper published by NWRI in April 2010 identifies key issues that would need to be addressed by regulatory agencies and utilities in California interested in pursuing direct potable reuse as a viable option to satisfy future water demands. To download the NWRI White Paper, click here.




Recycled Water To Faucets?

This video was prepared by the Central Basin Municipal Water District in August 2013. To some, recycled water raises a "yuck factor." Jeff Mosher, NWRI Executive Director, talks about the challenges and perceptions of recycled water. It's all part of a "behind the scenes" look at Central Basin's Caucus Speakers. Watch the video on YouTube.




Trends in Indirect and Direct Potable Reuse

George Tchobanoglous of the University of California Davis speaks on "Trends in Indirect and Direct Potable Reuse" at the 2012 NWRI Clarke Prize Conference on "Research and Innovations in Urban Water Sustainability." The conference was held by NWRI in November 2012.  Bruce Rittmann of Arizona State University provides an introduction.  Watch the video on YouTube.





CUWA/WateReuse/NWRI Direct Potable Reuse Workshop

Held April 26-27, 2010, in Sacramento, California


This workshop report summarizes comments made at the Direct Potable Reuse Workshop, which was held by the California Urban Water Agencies (CUWA), WateReuse Association California Section, and NWRI. These organizations collaborated to provide a forum to work on issues related to direct potable reuse topics, identify areas of potential collaboration, and avoid duplicative efforts.


Click here to download the workshop report (41 pages).



Panel membersWorkshop for NWRI Panel Examining the Criteria for Direct Potable Reuse

Held August 29, 2012, in Los Angeles, California


A WateReuse Foundation Project (WRF-11-02) was undertaken by Trussell Technologies, Inc. to assess the equivalency of advanced treatment trains for DPR and determine what modifications are necessary to satisfy public health criteria.


As part of this effort, Trussell Tech retained NWRI to coordinate an Independent Advisory Panel to lead a 2-day workshop in 2012 to develop a set of criteria that are protective of public health to evaluate treatment technologies for DPR. The final product is a Panel report published in 2013 by NWRI and the WateReuse Foundation.


Please click here for more information, including downloads of the workshop presentation slides.