- [See Oregon Water Quality Standards ]
(Effective November 17, 2017) State regulation establishing water quality standards for surface waters of the state. Please note that not all parts of this document are effective for Clean Water Act purposes. Refer to cover pages for more information.
- Final Rule - Aluminum Aquatic Life Criteria Applicable to Oregon Fresh Waters (December 30, 2020)
- 40 CFR §131.41 Bacteriological criteria for those states not complying with Clean Water Act section 303(i)(1)(A)
- 40 CFR §131.46 Aquatic life criterion for cadmium in Oregon
EPA's recent actions along with supporting documents are provided below for reference.
November 17, 2017 - EPA approved revised bacteria water quality standards that Oregon submitted to EPA on September 7, 2016.
January 9, 2017 - EPA approved revised acute and chronic aquatic life criteria for freshwater copper that Oregon submitted to EPA on November 14, 2016.
August 4, 2015 - EPA approved revised water quality standards adopted by Oregon on January 7, 2015. The revised standards include freshwater aquatic life criteria for ammonia, correction of the pH standard for the main stem Snake River, amendments to Oregon Administrative Rules (OAR) 340-041-0310 and OAR 340-041-0315, and numerous editorial revisions.
April 11, 2014 - EPA finalized action on revised aquatic life criteria adopted by Oregon on December 12, 2013.
September 19, 2013 - EPA approved a provision that allows Oregon to exempt certain "recurring activities" from state antidegradation review requirements, as it applies to nonpoint sources of pollution. The approval was in response to a January 7, 2013 court order from the federal District Court for the District of Oregon, which required EPA to take action under the Clean Water Act on the provision.
- EPA's September 19, 2013 Approval of Oregon's Antidegradation Provision at OAR-340-041-0004(4) (PDF) (3 pp, 375 K)
August 8, 2013 - In response to a federal district court order, EPA disapproved Oregon’s natural conditions criteria for temperature and statewide narrative natural conditions criteria, and reviewed the non-binding portions of Oregon’s antidegradation implementation methods. The court order did not affect the existing numeric, biologically-based temperature criteria, which remain in place.
- EPA's August 8, 2013 Disapproval of Oregon's Natural Conditions Criteria for Temperature, and Statewide Narrative Natural Conditions Criteria (PDF) (4 pp, 616 K)
- EPA's August 8, 2013 Review of Non-binding Portions of Oregon's Antidegradation Implementation Methods (PDF) (36 pp, 1 MB)
January 31, 2013 - EPA finalized action on new and revised aquatic life criteria for toxic pollutants submitted by Oregon in July 2004, as amended by its April 2007 and August 2011 submissions.
- EPA's January 31, 2013 Action on Oregon's New and Revised Aquatic Life Criteria for Toxics (PDF) (4 pp, 2 MB)
- EPA's Clean Water Act 303(c) Determinations on Oregon's New and Revised Aquatic Life Criteria for Toxics (PDF) (65 pp, 1 MB)
- Aquatic Life Criteria Submitted by Oregon (PDF) (27 pp, 433 K)
- Supplemental Technical Support Documents for EPA's Clean Water Act 303(c) Determinations (PDF) (735 pp, 6 MB)
- EPA's Responses to Supplemental Comments Concerning Oregon's New and Revised Aquatic Life Criteria (PDF) (64 pp, 416 K)
- Aquatic Life Criteria in Effect for Clean Water Act Purposes (PDF) (17 pp, 258 K)
October 17, 2011 - EPA approved revised water quality standards for toxic pollutants in Oregon based on a fish consumption rate of 175 grams/day.
- EPA's October 17, 2011 Approval of New and Revised Human Health Water Quality Criteria for Toxics (PDF) (6 pp, 408 K)
- EPA's Technical Support Document for Action on Oregon's New and Revised Human Health Water Quality Criteria for Toxics (PDF) (103 pp, 829 K)
June 1, 2010 - EPA finalized action on new and revised human health criteria for toxics in Oregon, and revisions to narrative toxics provisions.
- EPA's June 1, 2010 Action on Oregon's Human Health Water Quality Critera for Toxics (PDF) (5 pp, 45 K)
- Technical Support Document for Action on Oregon's New and Revised Human Health Water Quality Criteria for Toxics (PDF) (66 pp, 2 MB)
- EPA’s Approval of Oregon’s Surface Water Quality Standards for Bacteria (PDF)(58 pp, 16 MB)
- Oregon Water Quality Standards (PDF)(226 pp, 21 MB)