Completed – Spring 2005
The Denny Way/Lake Union Combined Sewer Overflow Control Project is a joint effort of King County and the City of Seattle to control combined sewer overflows (CSOs) into Lake Union and Elliott Bay. CSOs are overflows of sanitary (residential and commercial) sewage and stormwater that are released into water bodies during storms.
Dedication ceremony held Thursday, July 7, 2005
After nearly 12 years of planning and more than four years of construction, the Denny Way/Lake Union Combined Sewer Overflow Control Project is complete. This joint project with the City of Seattle is one of the most significant public investment efforts undertaken by King County and the largest of all county CSO control systems.
We want to express our appreciation to members of the community, organizations and businesses affected by construction—and to agencies, officials, employees, and companies that supported this major effort to protect public health and the environment.
Ongoing monitoring: Denny Way/Lake Union CSO Control Project Outfall Sediment Monitoring
King County is conducting a long-term sediment monitoring program for the Denny Way/Lake Union Combined Sewer Overflow (CSO) Control Project to fulfill requirements of the Biological Opinion issued by the National Marine Fisheries Service. The chemistry and benthic community data for program monitoring years 1–5 (2006–2010) and Year 10 (2015) are included in the monitoring report: Denny Way/Lake Union CSO Control Project Long-Term Sediment Monitoring Program Data Report Years 2006-2010 and 2015. Although the monitoring program is not complete yet (monitoring years 15 and 20 will occur in 2020 and 2025), this report evaluates the current status of the Denny Way site.