Skip to main content



Carnation Treatment Plant

In addition to award-winning wastewater treatment, operations at the Carnation Treatment Plant support a healthy future in the following ways:

Reclaimed Water

King County recycles water at all our treatment plants. At Carnation, recycled water is sent to the Chinook Bend Natural Area for wetland enhancement. The wetland enhancement project was designed in partnership with the Snoqualmie Tribe, Ducks Unlimited, and other interested stakeholders. The project design focused on enhancing native plants, installing new water control structures, and daylighting the water flowing in and out of the wetland. These benefits increased the size of the wetland and created both enhanced wildlife habitat and opportunities for passive recreation.

Learn more:

  • Explore King County’s resource recovery program here.
  • Learn about park features of the Chinook Bend Natural Area here.

Energy Conservation

Saving energy is a key part of King County Executive’s Strategic Climate Action Plan. Carnation Treatment Plant continuously scans the system and implements projects to save energy while maintaining and improving efficiency and performance.

Loop® biosolids

For over 40 years, King County Wastewater Treatment Division has recycled the nutrients in our food back to the land the same way nature does. Loop® is a fertilizer alternative produced by cleaning, recycling, and transforming wastewater into biosolids. We use it on farms and forests to generate healthier, more productive soil that increases crop yields and boosts tree growth. You may see Loop® trucks coming and going from Carnation. Learn about Loop® biosolids here.

Contact us

24 hour emergency and odor reporting:   206-263-1760
Administration:  206-263-1760 

4405 Larson Ave.
Carnation, WA 98041

Directions and map