Wastewater Treatment Plant

The three major wastewater treatment plants (WWTP) in the Middle and Little Spokane watersheds are those of the Cities of Dear Park, Liberty Lake, and Spokane. The rest of wastewater in the watershed is discharged through septic systems back to groundwater. The Deer Park WWTP treats wastewater and discharges it to an infiltration field (land application). This water then recharges to the ground and undergoes additional treatment through natural filtering in the soils.

Liberty Lake Sewer and Water was formed in 1973 by the residents of Liberty Lake with assistance from the Liberty Lake Property Owner's Association for the express purpose of restoring Liberty Lake. The District is presently discharging over 750,000 gallons per day of treated effluent to the Spokane River.

Wastewater from much of the urbanized Spokane area is collected and treated at the City of Spokane Riverside Park Water Reclamation Facility, which is located downstream of the WRIA 55/57 watersheds. Regional efforts to site a second WWTP between Spokane Falls and the Idaho border are on-going to serve the rapidly growing population in the Spokane Valley.