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Wastewater from houses and businesses in parts of Northeast King County and Southeast Snohomish County is piped and pumped to the Brightwater Treatment Plant for treatment and resource recovery.

Some of the treated water is reclaimed and the rest pumped through a pipeline and outfall to Puget Sound.

rsz_10211554675_9ffbda55a2_zTreatment plant operator

View more photos on our Flickr site  .

Contact us

24 hour emergency and odor reporting:   206-263-9500
Administration:  206-263-9465

22505 State Route 9 S.E.
Woodinville, WA 98072-6010

Directions and map

There are four treatment plants in the King County East Section Service Area. South Treatment Plant is the lead facility for the Brightwater Treatment Plant  in Woodinville, Carnation Treatment Plant, and Vashon Treatment Plant.

Pump stations, also often referred to as lift stations, are responsible for "lifting" the wastewater up and allowing it to flow back into the gravity conveyance system. Some pump stations apply pressure to a conveyance pipe—those sections of pipe are referred to as force mains.

  • Side sewers (also known as lateral sewers) are found on private property. These pipelines are the responsibility of the home/property owners and are generally 4–6 inches in diameter.
  • Local sewers are managed by cities and water districts. These pipelines move water between private property and the regional sewer system. These pipes are generally between 6 inches and 3 feet in diameter.
  • Regional sewers are managed by King County—they collect the water from the cities and water districts and move it to treatment plants for treatment and resource recycling. These pipelines can range from 2 to 14 feet in diameter.

Learn more about the Brightwater conveyance system and marine outfall  .

Know your sewer system—know who to call. Download this fact sheet  and record emergency contact numbers in case of a sewage overflow.

A combined sewer system collects stormwater and wastewater in the same pipe. Brightwater, South Plant, and King County's East Service Area are a separated sewer system. More about King County's Combined Sewer Overflow program

After disinfection, the water at Brightwater reclaimed water facilities is approximately 99.9 percent cleaner than when it came into the plant. It is clean enough to meet Class A reclaimed water standards for non-potable uses such as irrigation and industrial processes. Learn more.