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King County prepares an annual report on its CSO control program and what happened at each of our 38 CSOs over the past year. This report is submitted to the Washington State Department of Ecology (Ecology) and the U.S. Environmental Protection Agency (EPA).
Protecting Our Waters projects are planned and prioritized years in advance. King County reviews the program and updates the plan as part of the application for renewal of the county’s West Point Treatment Plant NPDES Permit.
In 2013 King County signed an agreement with the EPA and Ecology. This agreement, called a “consent decree,” requires us to complete our CSO control plan by 2030. In 2019, we asked to begin negotiations to modify the agreement because conditions had changed since the consent decree was approved.
Establish baseline conditions King County can use to monitor how conditions change after we build CSO projects.
Sharing what we learn
Many people work hard to improve water quality. King County partners with others to achieve our region’s goals.
The City of Seattle has a similar program for Protecting Seattle’s Waterways. The two agencies continue to work together to get the most out of these water quality investments and coordinating with each other on studies like this one.
The Water Quality Assessment and Monitoring Study can support many more water quality efforts, including these:
This study was completed in 1998 with help from a large stakeholder group and the Water Environment Research Foundation and describes the effects of CSOs on the Duwamish River and Elliott Bay. A new Water Quality Assessment and Monitoring Study began in 2013.