Historical Information on Washington State’s Water Quality Assessments, 303(d) Lists & 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.

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.

2004 Water Quality Assessment

The Department of Ecology completed Washington State’s Water Quality Assessment for 2002/2004. Ecology submitted the Water Quality Assessment to EPA on June 2, 2005, as an “integrated report” to meet the Clean Water Act requirements of sections 305(b) and 303(d). EPA approved Category 5 of the Water Quality Assessment (PDF) on November 4, 2005. Category 5 represents the state’s 303(d) list of impaired waters.

To browse the approved 2004 Category 5 water quality listings, as well as other categories use the simple query tool or interactive mapping tool.

To view the 2004 listings for contaminated sediments, please go to the contaminated sediments page.

303(d) Lists for Previous Years

In both the 1996 and 1998 lists, the primary water quality problems in our state’s waters were temperature and fecal coliform bacteria. Both are generally associated with nonpoint source pollution – that is, pollution which comes from many diffuse sources, not just from the end of a pipe.

Temperature is significant for the health of aquatic life. Salmon, especially, and other fish need cooler temperatures to survive and spawn. High temperatures can occur due to the discharge of hot water from power plants and industrial sources or, more often, from loss of vegetation along streams that used to shade the water and from new land uses (buildings and pavement) from which rainfall picks up heat before it runs off into the stream.
Fecal coliform bacteria is significant for human health as an indicator of the presence of disease-carrying organisms. It commonly comes from livestock and failing septic tanks.

303(d) Reports:

2006: The 2008 listing cycle satisfies EPA requirements for both the 2006 and 2008 assessment periods.

2004 Water Quality Assessment

2000: EPA did not require a report for 2000.

1998 303(d) List

1996 303(d) List

305(b) Report

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.

305(b) Reports:

2002 305(b) Report

2001 305(b) Report

2000 305(b) Report

1998 305(b) Report (PDF)

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

POB 47600

Olympia, WA 98504-7600

Phone: 360.407.6782

FAX: 360.407.6426

Email: 303d@ecy.wa.gov

Last updated February 2008