Tumwater Falls photo.  Author unknown.

Historical Information on Washington State’s Water Quality Assessments, 303(d) Lists and 305(b) Reports

About the 303(d) List

Section 303(d) of the federal Clean Water Act requires Washington State to periodically prepare a list of all surface waters in the state for which beneficial uses – such as for drinking, recreation, aquatic habitat, and industrial use – are impaired by pollutants. These are water quality limited estuaries, lakes, and streams that fall short of state surface water quality standards, and are not expected to improve within the next two years.

The Department of Ecology’s assessment of which waters to place on the 303(d) list is guided by federal laws, state water quality standards, and the Policy on the Washington State Water Quality Assessment (PDF). This policy describes how the standards are applied, requirements for the data used, and how to prioritize TMDLs, among other issues. The goal is to make the best possible decisions on whether each body of water is impaired by pollutants, to ensure that all impaired waters are identified and that no waters are mistakenly identified.

2008 Water Quality Assessment

The Environmental Protection Agency (EPA) approved Category 5 of the Water Quality Assessment on January 29, 2009.  Category 5 represents the state’s 303(d) list of impaired waters.

To browse the approved 2008 Category 5 water quality and contaminated sediment listings, as well as other categories, use the simple query tool or interactive mapping tool.

303(d) Lists for Previous Years

305(b) Reports for Previous Years

The Section 305(b) report, required by the Federal Clean Water Act, describes the current conditions of the state's waters to the U.S. Congress and the public. It is a state-wide assessment of the status of all the state's waters, whereas the 303(d) list reports just on the impaired waters of the state.

If you have questions or need specific information on past Water Quality Assessments or past 303(d) lists, please contact:

Ken Koch
Water Quality Program
WA Department of Ecology
PO Box 47600
Olympia, WA  98504-7600
Phone:  360.407.6782
FAX:  360.407.6426
Email:  303d@ecy.wa.gov

 

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Last updated February 2009