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National Pollutant Discharge Elimination System (NPDES)

Permit Limits-Recreational Water Quality Criteria Limits

This set of questions and answers provides an overview of NPDES permitting applicable to continuous dischargers (such as POTWs) based on water quality standards for pathogens and pathogen indicators associated with fecal contamination in primary contact recreational waters. These questions and answers help EPA, state, tribal and territorial NPDES permit writers understand implications of changes to state water quality standards based on the 2012 Recreational Water Quality Criteria (RWQC), published November 29, 2012.

The 2012 RWQC recommendations are for two bacterial indicators of fecal contamination, enterococci and E. coli. Section 304(a)(9) of the Clean Water Act directed EPA to publish new or revised water quality criteria recommendations for pathogens and pathogen indicators for the purpose of protecting human health. A pathogen indicator, as defined in section 502(23) of the CWA, is “a substance that indicates the potential for human infectious disease.” Most strains of enterococci and E. coli do not cause human illness (that is, they are not human pathogens); rather, they indicate the presence of fecal contamination.

These questions and answers provide advice on how to establish water quality-based permit limits in National Pollutant Discharge Elimination System permits for recreational water quality criteria. The statutes and regulations cited in this document contain the requirements applicable to NPDES permitting. The document does not impose legally binding requirements on EPA, states, tribes, other regulatory authorities, or the regulated community, and might not apply to a particular situation based upon the circumstances.

EPA, state, tribal and other decision makers retain the discretion to adopt approaches on a case-by-case basis that differ from those provided in this guidance where appropriate and consistent with statutory and regulatory requirements. EPA may update this document in the future as new information becomes available.

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