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WWTPClick photo for a video tour of the Wastewater Treatment Plant (video provided by CH2M)

College Place's wastewater treatment facility is owned by the City and operated by CH2M and presently serves a population of approximately 9,300 residents.  Built in 2001, the College Place Wastewater Treatment Plant is a 2-million-gallon-per-day complete-mix activated sludge /sequencing batch reactor plant. Wastewater is delivered to the plant by  a collection system. 

The plant is located on 430 Owens Rd and is open for guided tours. Please contact our office to reserve a time for your group to tour our facility.

A Department of Ecology Permit Report On Our Plant is located here. 

The City's wastewater system is separated into collection and treatment. The collection system andTreatment is managed under a contract with CH2M.

For information on the Wastewater Plant Facility Plan Update, click here.

SW Sewer Collection System General Sewer Plan

Sewer Backup Information

To report a sewer backup during normal business hours, please contact City Hall at 509-529-1200 or willy.breshears@CH2M.com.  If this is an emergency after hours, please call the 509-527-1960.

Wastewater System Ban List

Wastewater treatment is a biological process. Never dispose any of the following down your (street) storm drain or sewer (toilet, sink or any drain in the house) to the wastewater/sewer system:  

  • Pharmaceuticals
  • Excessive amounts of bath or body oils
  • Water softener backwash
  • Household cleaners, especially floor wax and rug cleaners
  • Chlorine bleach, chlorides, and pool or spa products
  • Pesticides, herbicides, agricultural chemicals, or fertilizer
  • Flammable or toxic products