Water Quality | Water Quality Standards and Classification

Bacteria Criteria

A frequent topic in NEIWPCC's Water Quality Standards Workgroup is EPA's guidance relative to bacteria criteria. The Implementation Guidance for Ambient Water Quality Criteria for Bacteria was written to provide guidance to state, territory, and authorized tribal water quality programs on the adoption and implementation of bacteriological water quality criteria for the protection of waters designated for recreation, that is, those waters used for swimming, kayaking, canoeing, white-water rafting, or simply enjoyed while hiking or bird watching.

As part of its recommendations, EPA is encouraging states and authorized tribes to use E. coli or enterococci as the basis of their water quality criteria for bacteria to protect fresh recreational waters. For marine recreational waters, EPA recommends the use of enterococci as the basis for water quality criteria for bacteria. Further, for coastal recreational waters (i.e., marine waters, coastal estuaries, and the Great Lakes), states were required to adopt bacteriological criteria as protective as EPA's Clean Water Act §304(a) criteria recommendations by April 2004. EPA believes the use of E. coli and/or enterococci is the best way to prevent acute gastrointestinal illness caused by the incidental ingestion of water from fecally contaminated recreational waterbodies.

The complete version of the guidance is available on EPA's Web site at http://www.epa.gov/waterscience/standards/bacteria