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

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

System planning phase

System planning

What happens during the system planning phase

RWSP planned projects through 2030
Planning and building new wastewater infrastructure is extremely complex. It can easily take a decade or more to go from identifying a project need to cutting the ribbon on a newly completed facility. Learn more.

The County identifies projects necessary to fulfill the Regional Wastewater Services Plan (RWSP), adopted in 1999 to ensure the system meets the region’s growth through 2030.

How King County works with the community

The goal of public outreach efforts during the System Planning Phase is to provide the public with opportunities to provide input on long-range decisions and to ensure decision-makers have access to public opinions.

Public outreach activities during this phase could include

  • Stakeholder workshops
  • Community presentations
  • Educational outreach
  • Annual Ratepayer Report
  • Program reports and updates
  • News releases
Learn more about Project Planning Learn more about Project Design Learn more about Project Construction Learn more about Facility Operations

Issues considered

Long-range decisions considered during this phase support the implementation of the RWSP’s major components, including:

Move to next phase (Project planning).