Water Quality Assessment Category 4b

Ecology recognizes that communities do not have to wait for a formal TMDL planning process. They can take the initiative to create programs to clean up polluted waters. Because these programs are locally controlled, there is an opportunity to reduce overall costs and the communities can exert greater control over the cleanup process.

Category 4b is intended for water bodies with a pollution control program in place that is expected to solve the pollution problems. While pollution control programs are not TMDLs they must have many of the same features, and there must be some legal or financial guarantee that they will be implemented.

To be placed in the Has a Pollution Control Project category, the pollution control project must meet all of the following criteria: Alpowa Creek, 2004, after applying riparian buffers.  Photo courtesy of Chad Atkins, WA Department of Ecology.

In addition to the conditions above, the project is more likely to gain approval if the following elements are included:

Several programs have been accepted by Department of Ecology and the Environmental Protection Agency as qualifying 4b programs. Accordingly, the Category 5 waters in these programs were moved (on the 303[d] List) to Category 4B.

Please use the following links for more information about these programs:


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Last updated August 2016