EPA: Aquatic Life Ambient Water Quality Criteria

EPA's recommended aquatic life ambient water quality criteria for toxics are levels of a pollutant or other measurable parameter that allows for protection of aquatic life in our nation's waters. Water quality criteria can be numeric (e.g., the maximum pollutant concentration levels permitted in a water body) or narrative (e.g., a criteria that describes the desired conditions of a water body being "free from" certain negative conditions). States, territories and authorized tribes typically adopt both numeric and narrative criteria. These aquatic life criteria are developed under Section 304(a) of the Clean Water Act.

National water quality criteria for the protection of aquatic organisms and their uses:

• National Recommended Water Criteria - Aquatic Life Criteria Table
• Guidelines for Deriving Numeric Aquatic Life Criteria
• EPA Activities Related to Revising the Aquatic Life Guidelines
• Common Effects Methodology for Pesticides
• Contaminants of Emerging Concern including Pharmaceuticals and Personal Care Products
• Other Aquatic Life Information
  • Draft Field-Based Methods for Developing Aquatic Life Criteria for Specific Conductivity
  • Final EPA-USGS Technical Report: Protecting Aquatic Life from Effects of Hydrologic Alteration
  • Aquatic Life Ocean Acidification and Marine pH
  • White Paper: A Summary of the Literature on the Chemical Toxicity of Plastics Pollution on Aquatic Life and Aquatic-Dependent Wildlife
  • Request for Nominations of Experts to Augment the Science Advisory Board Ecological Processes and Effects Committee to Provide Advice on Methods for Deriving Water Quality Criteria for the Protection of Aquatic Life