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

Murray CSO control project

Project design

April 2013 Update -- Coming to your neighborhood: a cleaner Puget Sound 
King County submitted its design for the Murray Combined Sewer Overflow Control Facility to the Washington State Department of Ecology in December 2012. The facility’s one-million gallon storage tank will be built across from Lowman Beach Park and will help keep Puget Sound clean by storing excess sewage and stormwater during storms for reentry into the County conveyance systems for treatment, once storms have passed. Existing structures will be deconstructed as early as late spring and construction will begin in late 2013. To learn more, view project update (PDF, April 2013).

Learn more about Final Facility Design
Final Design
, December 2012

Murray basin and project location
Murray basin and project location

Project description

King County is designing an underground storage tank across the street from Seattle’s Lowman Beach Park. The tank will store approximately one million gallons when the Murray Pump Station exceeds maximum capacity.

Why do we need this project?

Protect public health

Like many cities around the country (external link), the older parts of King County's wastewater system uses a single set of pipes to carry untreated sewage and stormwater to a treatment plant. To prevent sewer backups into homes and streets, the system includes safety valves called “combined sewer overflows” that route excess sewage and sewage flow directly into Puget Sound during storms. Although CSOs reduce potential exposure to untreated sewage, they pose significant public health concerns.

Clean up Puget Sound

The Murray CSO control facility will reduce CSOs into Puget Sound. State regulations require no more than one untreated discharge per year. The Murray Pump Station averages five untreated CSO events per year, discharging 5 million gallons into Puget Sound off of Lowman Beach Park.

Project Schedule

December 30, 2010
Submited draft Facility Plan to Department of Ecology
April-May 2011
SEPA threshold determined and public comment period
Summer 2011
Design team formed
Fall 2011
Ecology approves Facility Plan
Fall 2011
Community outreach begins (view meeting calendar)
Fall 2011-Fall 2012
Permitting
March 2012
Preliminary design complete
Spring 2012
Materials salvaged from onsite buildings
Summer 2012
Hazardous materials removed from buildings
Fall 2012
Onsite buildings deconstructed
2012
King County submits final design to Ecology for approval
2013-2016
Construction

View project meeting calendar.

How has the community shaped facility design?

Since October 2011 Lowman Beach Park neighbors and park users have worked with local designers, environmentalists and community advocates to help the King County project team design a facility that fits with the community. These discussions produced “common themes” for the design that reflect the community’s values for a safe, reliable facility. The common themes are:

  • Minimize the “industrial facility” feel
  • Encourage views of Puget Sound
  • Discourage through traffic on Beach Drive
  • Enhance continuous space between Lowman Beach park and the facility site

News releases

Project updates 

Find out if a CSO is occurring in Murray

Related information

For more information