Water quality standards are the foundation of the water quality-based control program mandated by the federal Clean Water Act. Water quality standards define goals for surface waters in Oregon by designating uses, setting criteria to protect those uses and establishing provisions to protect water quality from pollutants.
DEQ establishes water quality criteria for toxic pollutants to protect both aquatic life and human health. These criteria are established to protect surface waters for aquatic life use, to allow Oregonians to consume fish and shellfish, and to use state waters for drinking water supply without adverse health effects. DEQ develops its water quality criteria based on EPA recommended criteria and toxicity data, but sometimes modifies the federal criteria to protect local species and populations.
Current toxics standards
Note: Federally promulgated freshwater acute cadmium and freshwater acute and chronic aluminum aquatic life criteria are not reflected in Table 30, but are effective in Oregon for Clean Water Act purposes. See the
Hardness-Dependent Metals and
Aluminum web pages respectively, for more information.
Aquatic life toxics criteria
Aquatic life criteria are established to protect fish, shellfish, and wildlife. They represent the level of a chemical that can be present in a waterbody without causing harm to plants and animals. There are aquatic life criteria for freshwater and saltwater, and each pollutant has a criterion that applies for short-term (acute) and long-term (chronic) exposures.
On Jan. 31, 2013, following Endangered Species Act consultation, EPA disapproved several of the aquatic life criteria that the Environmental Quality Commission adopted in 2004. The pollutants included pesticides, cadmium (acute only), copper, ammonia and aluminum. Since 2013, DEQ adopted and EPA approved revisions to the disapproved criteria, or in the case of aluminum and acute cadmium, EPA promulgated federal criteria. See “Parameter Specific Information" below for more information.
Additional Resources
- Aquatic Life Water Quality Standards for Ammonia
- Freshwater Aquatic Life Water Quality Standards for Aluminum
- Freshwater Aquatic Life Water Quality Standards for Copper
- Hardness-Dependent Metals Aquatic Life Criteria
- Recommendations for analysis and implementation of other aquatic life toxic pollutants
- Arsenic, Sept. 7, 2021
- Chlorine, Feb. 22, 2023
- Chromium, Sept. 7, 2021
- Cyanide, Apr. 12, 2022
- DDT, July 22, 2024
- Endosulfan, July 22, 2024
- Hexachlorocyclo-hexane-Technical, July 22, 2024
- PCBs, July 22, 2024
Selenium, Oct. 21, 2014
Human health toxics criteria
Human health criteria establish goals for Oregon's surface waters, including protecting sources of drinking water and helping ensure that fish from Oregon's waters are safe to eat. These criteria establish chemical levels in water or tissue that are unlikely to cause significant risk to people. Human health criteria are designed to protect people from the effect of long term (i.e. lifetime) pollution exposure.
On June 16, 2011, the EQC adopted revisions to Oregon's water quality standards designed to reduce or prevent toxic pollutants in Oregon waterways. These standards establish goals for Oregon's surface waters, including protecting sources of drinking water and helping ensure that fish from Oregon's waters are safe to eat. EPA's approval makes the revised state standards, including new NPDES permitting implementation policies, effective for state and federal Clean Water Act programs. The U.S. Environmental Protection Agency approved the criteria on Oct. 17, 2011
In conjunction with revisions to the human health standards, DEQ revised certain water quality rules to clarify procedures and create new permitting tools (i.e. intake credits, a site-specific background pollutant criterion, and a revised variance rule) for implementing the standards. For more information about these revisions, please see the fact sheet and internal management directives below.
Additional Resources
- Human Health Criteria for Arsenic, Iron and Manganese
- Recommendations for analysis and implementation of other human health toxic pollutants
- 1,2 Diphenylhydrazine, Sept. 25, 2023
- Arsenic, Sept. 7, 2021
- Bis chloromethyl ether, Nov. 28, 2014
- Cyanide, Apr. 12, 2022
- Dinitrophenols, July 22, 2024
- DDT, July 22, 2024
- Endosulfan, July 22, 2024
- Hexachlorocyclo-hexane-Technical, July 22, 2024
- Methylmercury, March 2021
- Nitrosamines, July 22, 2024
- PCBs, July 22, 2024
Selenium, Oct. 21, 2014