National Recommended Water Quality Criteria

EPA's compilation of national recommended water quality criteria is presented as a summary table containing recommended water quality criteria for the protection of aquatic life and human health in surface water for approximately 150 pollutants.  These criteria are published pursuant to Section 304(a) of the Clean Water Act (CWA) and provide guidance for states and tribes to use to establish water quality standards and ultimately provide a basis for controlling discharges or releases of pollutants.

Criteria Tables:

  • Aquatic Life Criteria Table
    An aquatic life criterion for toxic chemicals is the highest concentration of a pollutant or parameter in water that is not expected to pose a significant risk to the majority of species in a given environment or a narrative description of the desired conditions of a water body being "free from" certain negative conditions.
  • Human Health Criteria Table
    Human health criteria are the highest concentration of a pollutant or parameter in water that is not expected to pose a significant risk to people.
  • Organoleptic Effects (e.g., taste and odor)

Criteria Documents:

In 1976 and in 1986 EPA published Quality Criteria for Water (known as the "Red Book" and the "Gold Book" respectively). The criteria in these documents are still current where a more recent criteria has not been published.