Updated: February 4, 2026

Project Update

This project is currently in the design phase and is approximately 90% complete.

What is this project going to accomplish?

Much of the infrastructure at the Wastewater Treatment Plant is over twenty years old and nearing the end of its useful life due to prolonged exposure to a harsh, corrosive operating environment. This project will provide improvements to the solids processing facilities.

The facility includes two enclosed tanks, known as digesters. Under this project, the digesters will be rehabilitated with new mixing, heating, and protective coating systems. The digesters store and condition solids for a specified period to reduce solids volume, minimize odors, and produce a biosolids byproduct suitable for beneficial use.

The boilers used to heat the digester contents will be replaced, enabling the use of biogas generated within the digesters as a primary fuel source. Excess biogas not required for heating will be combusted in a waste gas burner, which will also be replaced as part of this project.

These improvements will extend the service life of the solids handling assets, reduce reliance on natural gas, and support safer, more efficient operation and maintenance. The project consists solely of upgrades to existing facilities and does not include additions to the treatment process.

These improvements are required for the City to continue to meet discharge permit requirements as dictated by the Washington State Department of Ecology.  

Project Schedule

• Public Comment: Feb. 7 – March 13, 2026
• Design Completion: April 2026
• Construction Contract Advertisement: May 2026
• Construction: July 2026 – June 2027

How will this project be funded?

The total project cost is estimated to be approximately $10,000,000. Project funding has been provided by a $7,000,000 loan from the Washington State Department of Ecology, with the remainder being provided through a loan from the Washington Public Works Board.