Central Kitsap Treatment Plant

​The Central Kitsap Treatment Plant is a regional facility secondary clarifier at treatment plantdesigned to serve the central area of Kitsap County. The facility began operating in 1979 as a conventional activated sludge - secondary treatment facility. The treatment plant provides sewage service for the cities of Silverdale, Keyport, and Poulsbo, the Central Kitsap area, the Naval Submarine Base Bangor, and the Naval Undersea Warfare Engineering Station at Keyport.

Effluent from the Central Kitsap Treatment Plant is discharged to Port Orchard Bay, Puget Sound. The effluent is discharged   aerial image of Central Kitsap Treatment Plant approximately 3,200 feet offshore at a depth of 46 feet below mean low water.

The Central Kitsap Treatment Plant Resource Recovery & Process Improvement Project in Brownsville was completed in fall of 2015. This project addressed necessary repairs and rehabilitation of outdated and undersized sewage treatment equipment and also allows for the recovery of energy by capturing methane gas for co-generation of heat and electricity.


Treatment Plant Tour: Video
In collaboration with BKAT-TV, the Kitsap County Sewer Utility completed a 12-minute documentary highlighting the treatment process at the Central Kitsap Treatment Facility in Brownsville.  

CK Treatment Plant from BKAT TV on Vimeo.

Design Capacity
Average flow for the maximum month: 6.0 million gallons per day
Influent BOD5 loading for the maximum month: 14,100 pounds per day
Influent TSS loading for the maximum month: 11,400 pounds per day

Key Facts:

  • Treated 1.2 billion gallons of sewage in 2015
  • The average daily flow in 2015 was 3.4 million gallons of sewage
  • Removed 94% of the suspended solids and 95% of the Biochemical Oxygen Demand (BOD) before discharging the effluent into Puget Sound
  • Accepted 4.2 million gallons of septage from around the County
  • 849 dry tons of Biosolids were transported to either Eastern or Southwestern Washington for composting or land application