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Recreational Water Quality Criteria and Methods

EPA develops criteria to protect people from organisms, such as viruses and bacteria, and their associated toxins in water bodies (e.g., lakes, rivers, beaches).  Swimming and other recreational activities in contaminated water can make people ill.

EPA recommends criteria for limiting certain organisms and their associated toxins in water bodies to protect human health. State and tribal governments can use the criteria as guidance when setting their own water quality standards to protect human health.

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2012 Recreational Water Quality Criteria

EPA issued its current ambient water quality criteria recommendations for recreational waters in 2012 reflecting the latest scientific knowledge, public comments, and external peer review. The criteria are designed to protect the public from exposure to harmful levels of pathogens while participating in water-contact activities, such as swimming, wading and surfing, in all water bodies designated for such recreational uses.

Criteria Adoption and Implementation


Recreational Water Quality Criteria or Swimming Advisories for Cyanotoxins

EPA has issued final recommended recreational ambient water quality criteria or swimming advisories for two cyanotoxins, microcystins and cylindrospermopsin. The Agency has identified recommended concentrations of these cyanotoxins at or below which human health is protected while swimming or participating in other recreational activities in and on the water. States, territories, and authorized tribes can consider adopting these recommended criteria into their water quality standards and using them for Clean Water Act purposes. Alternatively, they can use these same values as the basis of swimming advisories for public notification purposes at recreational waters.

Criteria Adoption and Implementation

Draft Recreational Water Quality Criteria or Swimming Advisories for Cyanotoxins

This draft document is superseded by the final recommended criteria and swimming advisories published in 2019 and is available for informational purposes only.


Development of Recreational Water Quality Criteria for Coliphage

2016 Coliphage Experts Workshop

EPA held a Coliphage Experts Workshop in March 2016 as part of EPA’s ongoing efforts to build the scientific basis for developing coliphage-based water quality criteria.  EPA convened a group of twelve internationally recognized experts on the state of the science of coliphage and their usefulness as a viral indicator for the protection of public health in recreational waters. Experts represented a spectrum of perspectives from academia, federal agencies (EPA, CDC, FDA), and the wastewater industry. Agenda discussion topics included: the need for a viral indicator; coliphage as a predictor of gastrointestinal illnesses; how coliphage may be useful as an indicator of wastewater treatment performance; male-specific vs somatic coliphage; a systematic literature review of viral densities; and future research. The Coliphage Experts Workshop Proceedings document details the topics and overall findings from the Workshop. Additionally, the document provides the experts’ written responses to charge questions provided prior to the Workshop. The Proceedings document was recently peer-reviewed.

Review of Coliphages as Possible Indicators of Fecal Contamination for Ambient Water Quality

This is a literature review of the scientific information that EPA will evaluate to develop coliphage-based ambient water quality criteria for the protection of swimmers.  It generally indicates that coliphages are equally good indicators of fecal contamination as EPA’s currently recommended criteria for E. coli and enterococci. In addition, coliphages are better indicators of viruses in treated wastewater than bacteria. While EPA conducts its evaluation of coliphages as possible viral indicators for water quality, we continue to recommend that states adopt our 2012 recreational water quality criteria into their water quality standards. 

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