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Completed Spring 2017

Public involvementLibrary 

Community celebration and facility tours -- June 10th

Thanks for joining the King County WTD to celebrate the completion of the Murray CSO Control Project on June 10! We would like to thank community members and project neighbors for their patience and understanding during construction.


The public staircase is now complete!The public staircase provides access between Beach Drive SW and Lincoln Park Way SW.

operations phase

24-hour emergency and odor reporting:

Contact West Point Treatment Plant at  206-263-3801.

Facility address

7018 Beach Dr. S.W., Seattle

Project location


Back to the capital projects overview map .

See how public art at KCWTD facilities connects community to our system and the environment.

Project description

King County built a million-gallon underground storage tank across the street from Seattle’s Lowman Beach Park to reduce combined sewer overflows (CSOs). The tank stores excess stormwater and wastewater that would otherwise overflow into Puget Sound when the Murray Pump Station exceeds maximum capacity. Learn more about this project.

Project schedule

The Murray Wet Weather Facility began operating in November 2016. Project restoration was completed in spring 2017.


1702_landscaping_600Murray CSO Control Facility - view photos on flickr

Related information

Protecting Our Waters (Combined Sewer Overflow Control Program), King County

Find out if a CSO is occurring at Murray. King County maintains a real-time notification page so people can see whether CSO discharges are occurring.

This project is funded in part by:

Department of Ecology, State of Washington

Learn more

Protect public health

Like many cities around the country, 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 polluted stormwater 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 Wet Weather Facility was built to reduce CSOs into Puget Sound. State regulations require no more than one untreated discharge per year on a long-term average. Prior to construction of the Murray Wet Weather Facility, the Murray Pump Station averaged five untreated CSO events per year, discharging 5 million gallons into Puget Sound off of Lowman Beach Park.

About the Murray Wet Weather FacilitySource: Spring 2017 newsletter

Murray CSO Control Facility Site Plan  —slide 3 from the Final Facility Design Presentation, December 11, 2012

The new facility features the following elements.

  • Property acquisition
  • An underground diversion structure located in Beach Drive Southwest 
  • A pipe connecting the diversion structure to the storage tank to convey peak flows during a wet weather event
  • An approximately 6,000 square foot underground storage tank across from Lowman Beach Park
  • Retaining wall to protect the existing hillside along the northeast, east, and south edges of the storage tank site
  • One story equipment facility including mechanical and electrical facilities, located above the storage tank 
  • Landscape restoration in Lowman Beach Park and above ground at the storage tank site
  • A green roof with viewing areas
  • Public walkway through the site with rain garden
  • 3,500 square foot public use space north of facility


Interpretive signs

There are three interpretive signs located on top of the wet weather facility.

King County protects our waters on rainy daysView high-resolution version .

Protecting waters across the regionView high-resolution version .

Managing stormwater at our facilitiesView high-resolution version .

Visit the public involvement page to learn how the community shaped the facility design.