Water Quality

DEQ assessed water quality in Oregon to meet the federal Clean Water Act Sections 305(b) and 303(d) requirements to provide an Integrated Report on Oregon’s surface waters. DEQ prepared Oregon’s 2010 Integrated Report in phases and submitted a final 2010 Integrated Report to EPA in May 2011.

EPA approved the submitted 303(d) listings and de-listings on March 15, 2012 but also disapproved DEQ’s overall submittal for not including other waters. EPA proposed additions to Oregon’s 2010 303(d) list and took public comment on the additional listings. EPA completed its process and took final action on Oregon’s 2010 303(d) list on Dec. 14, 2012 by adding 870 listed segments.

With EPA’s action, the listings/de-listings approved in March 2012 and listings added in December 2012 complete Oregon’s 303(d) list and the list can be used for Clean Water Act purposes.

2010 Integrated Report

Assessment information available for the 2010 Integrated Report includes:

Oregon's 2010 Integrated Report – Assessment Database and 303(d) List
A searchable database report with data for each water body, pollutant and location that have been assessed, and the conclusion about water quality in each water body.

Search options to display data including:

  • All waters in the state for all pollutants and conditions
  • Waters that are Water Quality Limited (Category 4 and Category 5)
  • Waters where pollutant Total Maximum Daily Loads need to be developed (Category 5 303(d) list)
  • Waters that have been de-listed and removed from Category 5 (303(d) list) in the 2010 assessment


EPA action on Oregon’s 2010 303(d) List 

DEQ’s comments on EPA’s proposed 303(d) additions, April 2012

EPA approval/disapproval action, March 2012

Other Information

Methodology for Oregon’s 2010 Water Quality Report and List of Water Quality Limited Waters    (May 2011)
The methodology contains the protocols and decision rules DEQ used to evaluate data and assign an assessment status category to each water body where data were reviewed.

Oregon’s TMDL Priorities and Schedule (May 2011)

Response to Comments on Oregon’s Draft 2010 Integrated Report     (January 2011)

Response to Comments on Final Supplement to Oregon’s 2010 Integrated Report (May 2011)