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.