Recreational Water Quality Criteria and Methods
The U.S. Environmental Protection Agency 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.
The EPA's recommended criteria limit certain organisms and their associated toxins in water bodies to protect human health. State and tribal governments can use the recommended criteria as guidance when setting their own water quality standards to protect human health.
2012 Recreational Water Quality Criteria (RWQC) for Bacterial Indicators of Fecal Contamination
The 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.
The EPA issues such recommendations under the authority of the Clean Water Act (CWA). Amendments to the CWA by the Beaches Environmental Assessment and Coastal Health (BEACH) Act of 2000 directed the EPA to conduct studies associated with pathogens and human health, and to publish new or revised criteria recommendations for pathogens and pathogen indicators based on those studies. Prior to 2012, the EPA had last issued RWQC in 1986.
- Scientific Workshops and Research Supporting Development of the 2012 RWQC
- News Release: EPA Recommends New Recreational Water Quality Criteria to Better Protect Public Health (November 26, 2012)
- Fact Sheet: Revised: 2012 Recreational Water Quality Criteria (pdf)
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2012 Recreational Water Quality Criteria Document (pdf)
- Errata for Recreational Water Quality Criteria (pdf)
- Appendix A: Translation of 1986 Criteria Risk to Equivalent Risk Levels for Use with New Health Data Developed Using Rapid Methods for Measuring Water Quality (pdf)
- Appendix B: NEEAR data used for comparison to EPA's epidemiological studies from the late 1970s and early 1980s (pdf)
- Appendix C: Analysis of NEEAR culture data: combining marine and freshwaters (pdf)
- Docket with technical support documents (Docket ID EPA-HQ-OW-2011-0466)
Criteria Adoption and Implementation
The EPA’s nationally recommended RWQC are applicable for ambient waters designated for primary contact recreation. However, there are waterbodies with conditions that differ from those that formed the basis for the 2012 RWQC. Additionally, scientific advancements may provide additional approaches and new technologies for enumerating fecal-associated microbes. The EPA has developed two technical support documents (TSMs) to assist states and Tribes with deriving alternative RWQC for waterbodies with 1) predominantly non-human fecal pollution loading; or 2) a different microorganism and/or enumeration method than those the EPA recommended nationally in 2012. States and Tribes can transparently develop alternative water quality criteria that are scientifically defensible and protective of human health to the same level as EPA’s 2012 RWQC.
- Predominantly Non-human Fecal Sources
- This document describes the use of a quantitative microbial risk assessment (QMRA)-based approach to estimate recreator health risks from recreational exposure to waters with predominantly non-human fecal loading scenarios and to develop alternative water quality criteria based on the sources of fecal indicator bacteria and pathogens affecting a waterbody. Appendices in the document describe conducting a sanitary investigation, developing a sampling and analysis plan, and contain open-source code to assist running the QMRA analyses in Python or R.
- Technical Support Materials: Developing Alternative Recreational Criteria for Waters Contaminated by Predominantly Non-Human Fecal Sources (pdf)
- Alternative Indicators and Methods
- This document describes an approach to develop alternative WQC using enumeration methods for fecal indicator organisms that the EPA has not validated and issued. The document also provides a scientifically defensible approach for gathering the needed information and data to support the use of an alternative enumeration method. The EPA also provides a spreadsheet-based tool, “Alternative Methods Calculator Tool,” to be used in conjunction with the technical support document and a user’s guide for the tool. The Alternative Methods Calculator Tool calculates the index of agreement and R-squared values, and graphs user-collected water quality data.
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Site-Specific Alternative Recreational Criteria Technical Support Materials For Alternative Indicators and Methods (pdf)
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Spreadsheet: Alternative Methods Calculator Tool (xlsm) (69 KB, November 2021, EPA 821-B-21-002)
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Five-Year Reviews of the 2012 RWQC
The EPA is required by the BEACH Act amendments to CWA section 304(a)(9)(B) to conduct reviews every five years of the agency's RWQC. In conducting these reviews, the EPA considers several factors, such as the availability and evaluation of new science, the review of information related to the underlying science used to develop the RWQC, additional implementation support needs, and perceived barriers to state adoption. An important goal of these reviews is to document the assessment of whether revisions to the current RWQC are necessary.
Microbiological Test Methods for Ambient Waters
Secondary Contact Recreational Water Quality Standards
Adopting Water Quality Criteria for Secondary Contact Recreation: A User Guide
The user guide helps states and authorized Tribes utilize the scientific information in the white paper to protect their waters designated for secondary contact recreation.
2019 Recreational Water Quality Criteria or Swimming Advisories for Cyanotoxins
In 2019, the EPA 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 CWA purposes. Alternatively, they can use these values as the basis of swimming advisories for public notification purposes at recreational waters.
- Federal Register Notice: Recommended Human Health Recreational Ambient Water Quality Criteria or Swimming Advisories for Microcystins and Cylindrospermopsin (June 6, 2019)
- Fact Sheet: Recommended Human Health Recreational Ambient Water Quality Criteria or Swimming Advisories for Microcystins and Cylindrospermopsin (pdf)
- Document: Recommended Human Health Recreational Ambient Water Quality Criteria or Swimming Advisories for Microcystins and Cylindrospermopsin (pdf)
- Response to Comment: Recommended Human Health Recreational Ambient Water Quality Criteria or Swimming Advisories for Microcystins and Cylindrospermopsin (pdf)
Criteria Adoption and Implementation
The EPA published a final technical support document that explains how states, territories, and authorized Tribes may adopt the EPA’s 2019 recommended criteria for two cyanotoxins into their water quality standards or use the criteria in swimming advisory programs. The document also addresses implementation of the 2019 criteria recommendations through other CWA programs including identifying and listing of impaired waters, and total maximum daily load (TMDL) development.
Cyanotoxin Identification and Detection Methods for Drinking and Ambient Freshwaters
Under Development: Recreational Water Quality Criteria for Coliphage
2016 Coliphage Experts Workshop
The EPA held a Coliphage Experts Workshop in March 2016 as part of the agency's ongoing efforts to build the scientific basis for developing coliphage-based water quality criteria. The EPA convened a group of 12 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 (the EPA, the CDC, and the FDA), and the wastewater industry. 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 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 the 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 the EPA’s currently recommended criteria for E. coli and enterococci. In addition, coliphages are better indicators of viruses in treated wastewater than bacteria. While the EPA conducts its evaluation of coliphages as possible viral indicators for water quality, we continue to recommend that states adopt our 2012 RWQC into their water quality standards.
- Report: Review of Coliphages as Possible Indicators of Fecal Contamination for Ambient Water Quality