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King Street Center
201 S. Jackson St., Suite 500
Seattle, WA 98104-3855
Phone: 206-684-1280
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

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Puget Sound shoreline next to the West Point Treatment Plant, Seattle

Denny Way/Lake Union CSO Control Project

Facility operations

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

King County Wastewater Treatment Division Director Don Theiler addresses the crowd.
King County Wastewater Treatment Division Director Don Theiler addresses the crowd.

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 celebrated the project completion with a dedication ceremony Thursday, July 7, at the new Elliott West CSO Control Facility, 545 Elliott Ave. W.

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.

illustration of CSO control facility
Elliott West CSO Control Facility.
Learn more about this facility. 

Project news

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