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Water: Water Quality Criteria

Water Quality Criteria



Section 304(a)(1) of the Clean Water Act requires us 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 healthMore general information on criteria.

Current National Recommended Water Quality Criteria are available.

Aquatic Life

Aquatic Life criteria lists 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.

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

Human Health

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

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.

Recreational Criteria protect people who swim and play in coastal recreational waters from exposure to pathogens. We held an Experts Scientific Workshop to help map our future directions.

Other Useful Criteria Links

Development of criteria for suspended and bedded sediments.

Order Criteria Documents.

Water Quality Standards and Criteria Strategy

Reference library of guidance documents and policy memos.

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