Water Quality Assessment

Every two years, DEQ assesses water quality and reports to EPA on the condition of Oregon's waters. DEQ prepares an integrated report that meets the requirements of the federal Clean Water Act (CWA) for Section 305(b) and Section 303(d).

• CWA Section 305(b) requires a report on the overall condition of Oregon's waters.
• CWA Section 303(d) requires identifying waters that do not meet water quality standards where a Total Maximum Daily Load (TMDL*) needs to be developed.

The Integrated Report includes an assessment of each water body where data are available, and the list of waters identified under Section 303(d) as water quality limited needing a TMDL.

DEQ completed Oregon's 2004/2006 Integrated report in May 2006.  Oregon's 2004/2006 303(d) list was reviewed and approved by EPA in February 2007.

DEQ is currently working on Oregon's 2010 Integrated Report which will update Oregon's 303(d) list of water quality limited waters needing TMDLs.

 

Assessment Topics

Assessment Database

Oregon's 2010 Integrated Report Oregon's 2004/2006 Integrated Report Oregon's 2002 Integrated Report Oregon's 1998 303(d) List   Oregon's Section 305(b) Reports   Oregon Water Quality Index

Oregon's 2010 Integrated Report (in preparation) Oregon's 2004/2006 Integrated Report Database (includes water quality limited waters and 303(d) list) Map of Oregon’s Impaired Waters PDF (shows 2004/2006 Water Quality Limited Waters) Download GIS layers for Oregon's 2004/2006 Streams and Lakes Water Quality ZIP (6.58MB)  Note: Includes a line theme for streams and an updated polygon theme for lakes (v2 Jan 2008). The updated lake theme contains polygon features for all the records in the data attribute table. The line theme and the polygon theme should be used together to fully represent the data records in Oregon's 2004/2006 Integrated Report Assessment Database.

*A TMDL is the calculated amount of pollutant a water body can receive and still meet Oregon water quality standards.

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