The West Point plant is a secondary treatment facility that uses high-rate oxygen activated sludge technology.

Process diagram and data

• Treatment process diagram (updated 2018)
• Technical facts - English and Metric
• NPDES permit 

Odor control at West Point Treatment Plant

The look—and smell—of West Point Treatment Plant has changed a lot since the plant was first dedicated in 1966. Processes like solids settling were once carried out in sludge lagoons on the South Beach at Discovery Park. Today, treatment processes are enclosed and covered, and the area surrounding the treatment plant has been restored for public use and enjoyment.

Odor monitoring and control requirements

Although odors can be a problem in wastewater systems, King County works hard to be a good neighbor by monitoring and controlling odors at our facilities and making long-term improvements to odor control systems.

Both regulations and policies require King County Wastewater Treatment Division to monitor and control odors. West Point Treatment Plant is in compliance with odor control regulations established by Puget Sound Clean Air Agency and the City of Seattle.

24 hour emergency and odor reporting:  206-263-3840

Grit removal

View more photos on our Flickr site  .

West Point Treatment Plant, 1999

West Point Treatment Plant, 1974 (note sludge lagoons on the South Beach at Discovery Park)