South Magnolia CSO Control Project
February 2013 Update
Now posted: meeting summary (PDF) for the January 26, 2012 on-site community meeting at 32nd Avenue W, Seattle. The meeting purpose was to review conveyance pipeline installation options.
Learn more about the project design by downloading the Fall 2012 newsletter (PDF) and viewing past public meeting materials.
South Magnolia basin and project location.
South Magnolia CSO basin project area
How will the new CSO facility work? View animation.
King County is designing and building an underground storage tank in the Port of Seattle’s Terminal 91 West Yard south of the Magnolia Bridge. This facility will store peak combined sewer flows so that CSOs are limited to no more than one per year on a long-term average.
Why does King County need to do this project?
In 2008, King County reported that the South Magnolia combined sewer overflow (CSO) facility has 19 overflows per year on average that discharge a total of 31 million gallons of untreated wastewater and stormwater into Puget Sound off of South Magnolia. King County is working to meet current regulations set by the Washington Department of Ecology that require no more than one untreated discharge per year on a long term average.
||January 26, 2013
|Construction procurement process
|Pre-construction community meetings
|Construction (18-24 months)
||2013 - 2015
View meeting calendar for upcoming public meetings, and South Magnolia CSO Control Project Timeline (PDF), updated October 2012.