Holiday closure Monday May 28: Most county offices will be closed in observance of Memorial Day.

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: 206-684-1280
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

Get Directions to our office location in Seattle, Washington.

Staff Contacts

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

Matthews Park pump station and sewer improvement project

Facility operations

Completed fall 2006

Project site mapKing County protects public health and the environment by conveying and treating the region's wastewater. To ensure safe and reliable operations in the future, the King County Wastewater Treatment Division has completed three projects in the Matthews Beach area to upgrade aging infrastructure. These facilities carry wastewater from the north end of Lake Washington and the City of Seattle to the West Point Treatment Plant in Discovery Park.

What we've accomplished

Since 2002, King County has completed three projects in the Matthews Beach area to upgrade aging infrastructure:

  • Upgraded the pump station
  • Repaired corroded concrete inside the North Portal (entrance) to the Lake City Tunnel in 2002
  • In 2003, repaired the Matthews Park force main by slip lining the existing 42-inch pipe with a new plastic pipe. Slip lining the force main minimized construction-related disruption and extended the life of the pipe.

Construction updates

  • Fall 2006 (224KB, PDF)
  • September 2005 (579KB, PDF)
  • Summer 2005 (505KB, PDF)
  • Fall 2004 (540KB, PDF)