"Find a Water Quality Improvement Project" Map

This map shows the water quality improvement projects, including total maximum daily loads, managed by the Washington State Department of Ecology. The boundaries represent the area where the project applies. (Note: The web map may take a few seconds to display completely, depending on your internet connection speed.)

Total maximum daily load (TMDL) projects are required by the Federal Clean Water Act to identify pollution sources and pollution load reductions needed for water bodies to meet state water quality standards. Once a TMDL project is approved by the U.S. EPA, it enters an implementation phase where both point source and non-point source pollution is reduced through permit limits regulated under the NPDES system and through best management practices (BMPs) for land uses that contribute to non-point source pollution.

Category 4b projects are other water pollution control programs that have been approved by the U.S. EPA as part of the water quality assessment for Washington State.

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Last updated November 2016