These polygon features represent Water Quality Improvement (WQI) projects managed by the Washington State Department of Ecology. WQI projects can be TMDLs, Straight To Implementation (STI) plans, 4b projects and TMDL Alternatives. The boundaries show where the WQI project applies and is being implemented. TMDL Boundaries identified as "In Development" are considered draft and are subject to change when the project has been approved by the U.S. EPA. U.S. EPA only approves TMDLs and 4b projects. Boundaries are representations of each particular project and does not replace the official version of the approved TMDL report. Please see the TMDL Project webpage for specific information about that project. TMDL projects are required by the Federal Clean Water Act to identify pollution sources and pollution load reductions needed for water bodies to meet water quality standards. Once a TMDL project has been 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 for land uses that contribute to non-point source pollution. Ecology’s water quality program works with permittees, local governments, watershed stakeholders, and residents to reduce sources of pollution to protect our aquatic resources and public health.

These polygon features represent Water Quality Improvement (WQI) projects managed by the Washington State Department of Ecology. WQI projects can be TMDLs, Straight To Implementation (STI) plans, 4b projects and TMDL Alternatives. The boundaries show where the WQI project applies and is being implemented. TMDL Boundaries identified as "In Development" are considered draft and are subject to change when the project has been approved by the U.S. EPA. U.S. EPA only approves TMDLs and 4b projects. Boundaries are representations of each particular project and does not replace the official version of the approved TMDL report. Please see the TMDL Project webpage for specific information about that project. TMDL projects are required by the Federal Clean Water Act to identify pollution sources and pollution load reductions needed for water bodies to meet water quality standards. Once a TMDL project has been 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 for land uses that contribute to non-point source pollution. Ecology’s water quality program works with permittees, local governments, watershed stakeholders, and residents to reduce sources of pollution to protect our aquatic resources and public health.

These polygon features represent Water Quality Improvement (WQI) projects managed by the Washington State Department of Ecology. WQI projects can be TMDLs, Straight To Implementation (STI) plans, 4b projects and TMDL Alternatives. The boundaries show where the WQI project applies and is being implemented. TMDL Boundaries identified as "In Development" are considered draft and are subject to change when the project has been approved by the U.S. EPA. U.S. EPA only approves TMDLs and 4b projects. Boundaries are representations of each particular project and does not replace the official version of the approved TMDL report. Please see the TMDL Project webpage for specific information about that project. TMDL projects are required by the Federal Clean Water Act to identify pollution sources and pollution load reductions needed for water bodies to meet water quality standards. Once a TMDL project has been 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 for land uses that contribute to non-point source pollution. Ecology’s water quality program works with permittees, local governments, watershed stakeholders, and residents to reduce sources of pollution to protect our aquatic resources and public health.