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Project update

February 2023

We’re so close to being done and things are looking great!

We’re looking forward to our ribbon cutting celebration later this year after the artwork installation is complete. Stay tuned for more information about the celebration. Here are a couple of our favorite photos from the last few months as we complete finishing touches on the facility. Enjoy!

group of people in orange construction vests standing in front of a large industrial building Tour group standing on permeable pavement in front of the process building.

A view of the treatment station at nightView of the treatment facility at night. The blue lights in the photo will be on when the facility is working.

Want more photos? Check out our Flickr pages: Outfall, Conveyance, Treatment Station

What to expect in 2023:

  • Crews and staff on site
  • Art and educational sign installation
  • Theater of a storm artwork lit up when the facility is operational

Take a look at our virtual construction work through August 2020 at the Georgetown Wet Weather Treatment Station!
Mire nuestro trabajo de construcción virtual hasta agosto del 2020 en la Planta de almacenamiento de agua de lluvia de Georgetown!

King County’s Georgetown Wet Weather Treatment Station celebrates Platinum Achievement Award for Sustainability

King County’s Georgetown Wet Weather Treatment Station earned the coveted “Platinum” rating from the Institute for Sustainable Infrastructure’s Envision rating system. This is the first Platinum-awarded Envision project in Washington and recognizes the County’s commitment to sustainable communities and the environment.

Project description

Rendering of Georgetown Wet Weather Treatment SystemSite of future Georgetown Wet Weather Treatment Station at the corner of 4th Avenue South and South Michigan Street. (View other wet weather treatment facilities.)

The Georgetown Wet Weather Treatment Station Project includes the construction of a combined sewer overflow (CSO) wet weather treatment station between the Brandon Street and South Michigan Street Regulator Stations, related pipes and a new outfall structure to release the treated water into the Duwamish River. When constructed, the station can treat up to 70 million gallons of combined rain and wastewater a day that would otherwise have discharged directly to the Duwamish without treatment during storm events.

This project will help clean up the Duwamish River by treating stormwater runoff and sewage during heavy rains. Right now, heavy rains can fill up our sewer pipes, sending polluted runoff and sewage through a pipe into the river. King County began on-site work in April 2017 and expects to finish construction in 2022.

Wet Weather Treatment StationWet weather treatment stations clean overflows locally on-site during heavy rain storms.


Through a competitive process, King County awarded the construction contracts to three separate contractors.

In spring 2018, King County’s contractor Flatiron West, Inc. started treatment station construction. In the summer of 2018, Pacific Pile and Marine began the construction on the new outfall structure and in the fall of 2018, JW Fowler Company also began preparation work to construct the conveyance pipeline which will connect the treatment station to the outfall.

project timeline


Contact us

Construction hotline:

Contact Bibiana Ocheke-Ameh at:


 Feedback form

Facility Address:
6185 4th Ave S, Seattle, 98108

If you’d like to receive email or text updates on the Georgetown Wet Weather Treatment Station:

Project location

georgetown location on map

Back to the capital projects overview map .