Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Chemicals and Toxics
    • Climate Change
    • Emergency Response
    • Environmental Information by Location
    • Environmental Justice
    • Greener Living
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Pesticides
    • Radon
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Guidance
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • EPA Administrator
    • Organization Chart
    • Staff Directory
    • Planning, Budget, and Results
    • Jobs and Internships
    • Headquarters Offices
    • Regional Offices
    • Lab and Research Centers
Related Topics:
  • Water Research
Contact Us

Water Reuse Research

Additional EPA Information
  • Water Reuse Action Plan
  • Potable Water Reuse
  • Water Reuse and Recycling
  • 2012 Guidelines for Water Reuse
  • 2017 Potable Reuse Compendium
Recycling of water

Increasing pressures on water resources has led to greater water scarcity and a growing demand for sufficient quantities of high-quality water. An integrated One Water concept can facilitate meeting this demand by limiting discharges from wastewater treatment, identifying alternative water sources, recovering resources (e.g., water), developing methods to enhance the availability and quality of recycled water appropriate end uses, and creating tools to evaluate trade-offs and aid decision making for fit-for-purpose water reuse. Three general types of water reuse include the following (excludes agricultural, environmental, and industrial applications):

  • Non-potable water reuse – Water is captured, treated, and used for non-drinking purposes, such as toilet flushing, clothes washing, and irrigation.
  • Indirect potable water reuse – Water that will be treated with an environmental buffer and used for drinking water. For example, stormwater or wastewater is first directed to a municipal wastewater treatment plant for treatment. Once treated, it is then directed to an environmental buffer, such as a lake, river, or a groundwater aquifer that is used as a source drinking water. The water is then treated at a drinking water treatment plant and directed into the drinking water distribution system.
  • Direct potable water reuse – Water that will be treated and used for drinking water without an environmental buffer. In this scenario, stormwater or wastewater is directed to a municipal wastewater treatment plant and/or an advanced wastewater treatment facility for treatment. Once treated, it is then directed to a drinking water treatment plant for further treatment or sent directly to a drinking water distribution system.

EPA published the Guidelines for Water Reuse in 2012 as a general reference for water reuse practices, and the Potable Reuse Compendium in 2017 to inform current practices in the rapidly developing area of direct potable reuse. EPA supports water reuse as a component of integrated water management, and encourages states to use the Clean Water Act and Safe Drinking Water Act as foundational documents to develop their own water reuse strategies. To this end, EPA remains committed to active engagement and research, with various partners and stakeholders to ensure that implemented water reuse is protective of human health.

EPA Research

constructed wetland system used to treat blackwater for reuse.
The constructed wetland system at the San Francisco Public Utilities Commission headquarters treats  blackwater and then distributes the treated water for toilet flushing.
EPA’s research, including research collaborations with external partners, is proving guidance on new and existing water reuse practices with the overall goal of improving the quantity of high-quality water without creating other significant environmental impacts. Research includes
  • evaluating alternative water sources (wastewater, source separated greywater from sinks or showers, stormwater runoff, roof-collected rainwater, air-conditioning condensate) as resources for water reuse;
  • providing a better understanding of the potential health risks, cost effectiveness, and life-cycle impacts of various water reuse options and treatment configurations;
  • developing treatment targets and monitoring surrogates for onsite non-potable water systems; and
  • reducing contamination of groundwater sources by evaluating the use of stormwater management practices and expanded water reuse.

Research Areas

  • Onsite Non-Potable Water Reuse
  • ​Water Scarcity and Drought Grant Research
  • Human and Ecological Health Impacts Grant Research

Models and Tools

  • Non-Potable Environmental and Economic Water Reuse (NEWR) Calculator
  • EPA Science Models and Research Tools (SMaRT) Search

Related EPA Research

  • Wastewater Research
  • Stormwater Management Research
  • Health and Water Research
  • Nutrients Research
  • Water Research

Research Publications

  • Water reuse publications in Science Inventory
Contact Us to ask a question, provide feedback, or report a problem.
United States Environmental Protection Agency

Discover.

  • Accessibility
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data.gov
  • Inspector General
  • Jobs
  • Newsroom
  • Open Government
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.

Last updated on April 28, 2022