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Water Quality Standards Regulations: Oregon

Presented below are water quality standards in effect for Clean Water Act (CWA) purposes for this state.

EPA is posting these standards as a convenience to users and has made a reasonable effort to assure their accuracy. Also, for each document listed under "State Standards in Effect for CWA Purposes", EPA has made a reasonable effort to identify parts of the standards that are disapproved or are otherwise not in effect for CWA purposes.

On this page:

State Standards in Effect for CWA Purposes

  • [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.

Federally Proposed or Promulgated Standards

Selected Actions and Correspondence

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.

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. 

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.

October 17, 2011 - EPA approved revised water quality standards for toxic pollutants in Oregon based on a fish consumption rate of 175 grams/day.

June 1, 2010 - EPA finalized action on new and revised human health criteria for toxics in Oregon, and revisions to narrative toxics provisions.

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