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United States Environmental Protection Agency
Water Quality Criteria
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Section 304(a)(1) of the Clean Water Act requires EPA to develop criteria for water quality that accurately reflects the latest scientific knowledge. These criteria are based solely on data and scientific judgments on pollutant concentrations and environmental or human health effects. Section 304(a) also provides guidance to states and tribes in adopting water quality standards. Criteria are developed for the protection of aquatic life as well as for human health.

Aquatic Life criteria list chemical concentration goals to protect surface water for aquatic life use.

Biological criteria are based on the numbers and kinds of organisms present and describe the biological condition of aquatic communities inhabiting surface waters.

Microbial (Pathogen) criteria are used to protect the public from exposure to harmful levels of pathogens in ground and surface waters, food sources, and finished drinking water.

Development of criteria for suspended and bedded sediments

Order Criteria Documents

Human Health includes technical information and guidance on surface water, drinking water and microbials.

Nutrients are substances used by living things that promote growth (e.g., nitrogen and phosphorus). EPA is developing nutrient criteria to prevent overenrichment in surface waters of the U.S.

Criteria Table lists aquatic life, human health, and nutrient criteria for 158 pollutants as guidance for States and Tribes in adopting water quality standards for surface waters.

Water Quality Standards and Criteria Strategy

Rulemakings, Withdrawals, and Other Federal Register Notices

 

Water Quality Standards | Drinking Water | Research and Development

 
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