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Wastewater Treatment

King County, Washington

For questions about the Wastewater Treatment Division website, please send an e-mail message or contact us at:

King Street Center
201 S. Jackson St., Suite 500
Seattle, WA 98104-3855
Phone: 206-477-5371
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

Get Directions to our office location in Seattle, Washington.

Staff Contacts

Murray CSO control project -- Building a new storage tank to protect Puget Sound

Project Construction

August 25, 2015 - Pump Station connection work underway

Crews have begun installing a new five-foot pipe in Lowman Beach Park to connect the new underground storage tank to the Murray Pump Station (see map). This work will continue through early fall.

After the pipe is installed in the park, work will shift to the 7000 block of Beach Dr. S.W. Excavators will be used to install steel sheets and beams to hold soil and water back during pipe installation. Expect increased noise while these activities occur.

View construction update (PDF, August 21, 2015)

Bike safe on Beach Drive!
Uneven road conditions exist along the 7000 block of Beach Dr. S.W., just north of the trail to Lincoln Park due to construction. Please walk your bike next to construction area. View poster (PDF, August 10, 2015).

Utility work in Beach Drive S.W. begins in early August - expect lane closures and delays 

King County contractors will begin installing a five-foot wide pipe under Beach Drive S.W. this month. The pipe will connect the new tank to the Lowman Beach Pump Station. The work will take about three months to finish.

Construction activity in the 7000 block of Beach Drive S.W. will be intense during this work. Road surface conditions will vary due to saw cutting, temporary patches and steel plates on the roadway.

View construction update (PDF, August 3, 2015)


Learn more:  What to expect during concrete pours (Winter 2015)

Have a comment or question? Need more information about the project? 
Click here to contact the project team.

Murray Project Hotline: 206-205-9186

Learn more about Final Facility Design
Final Design
, December 2012

Haul routes
Project haul routes
, February 2014

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, 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 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

Construction schedule overview
View construction schedule overview (PDF) and 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

Southbound vehicles on Beach Drive SW can use the access road south of the park to turn around
Southbound vehicles on Beach Drive SW can use the access road south of the park to turn around.

Have a question or concern? Please use the project feedback form.

Project updates 

Find out if a CSO is occurring in Murray

Related information

For more information