From 2012 to 2017, the King County Wastewater Treatment Division conducted a Water Quality Assessment and Monitoring Study (WQA) of Lake Union/Ship Canal, Elliott Bay, and the Duwamish Estuary. The purpose of this study was to support planning for the combined sewer overflow (CSO) program and ensure remaining CSO projects are well-planned and timed to improve water quality in these waterbodies. King County is using the outcomes of the study to inform development of the 2018 update to the CSO long-term control plan, establish baseline conditions for mandatory post-construction monitoring of CSO control projects, and make technical information available to many organizations working to improve water quality. 

King County convened an independent five-member Science and Technical Review Team (STRT) to review the study and help ensure high quality methodology, analyses, and conclusions. The role of the STRT was to provide an independent assessment of the data quality, methodologies, assumptions, analyses, and conclusions King County used to develop the WQA. We also acted as a technical sounding board for King County, reviewing and commenting on technical questions and issues. Along the way, we shared our thoughts on how to present the analyses and conclusions to decision makers.