Water Quality

Information on EPA's disapproval action

On Aug. 8, 2013, EPA disapproved the natural conditions criterion contained in Oregon’s water quality standard for temperature. EPA also disapproved the general natural conditions criterion contained in Oregon’s statewide narrative criteria, which applied to other naturally occurring substances and conditions of water. See the “Questions and Answers” and the EPA action letter below for additional information.

Federal Court Opinions and Orders

            Oregon's temperature standard

Oregon’s current temperature standard was adopted by the Oregon Environmental Quality Commission in December 2003. The Environmental Protection Agency approved much of the standard in March 2004, and approved additional provisions in March 2010. DEQ revised the standard in February 2007 in response to EPA’s disapproval of the 2003 narrative criteria for cool water species, natural lakes and oceans and bays. EPA approved the revised narratives in February 2011.

Temperature Standard Rule - OAR 340-041-0028

            Information and guidance documents

            EPA temperature guidance