Spokane County, Washington: drinking water report. Spokane County – Spokane and surrounding communities – serves about 540,000 residents.
Spokane County – Spokane and surrounding communities – serves about 540,000 residents. The city draws from the Spokane Valley-Rathdrum Prairie Aquifer, one of the most productive aquifers in the Pacific Northwest. This sole-source aquifer sits beneath the Spokane Valley and extends into Idaho, providing water to communities on both sides of the state line. The aquifer's coarse gravel composition means water moves quickly through it – which is great for supply but makes it vulnerable to surface contamination.
The Spokane aquifer produces high-quality water that requires minimal treatment. The EPA designated it a sole-source aquifer in 1978, recognizing that there is no alternative supply. However, the aquifer's rapid flow characteristics mean contamination can spread quickly.
UCMR5 data shows low-level PFAS detections in some Spokane-area water systems. Fairchild Air Force Base, located west of Spokane, is a confirmed PFAS source. According to the Washington Department of Ecology, PFAS has been detected in monitoring wells near Fairchild, with some readings exceeding state action levels. The contamination has not yet affected the main Spokane aquifer, but the Department of Defense is conducting ongoing investigation.
Spokane's aquifer delivers excellent water, but its sole-source status means any contamination threat is existential for the supply.
Check your water for current data. For communities near Fairchild AFB, PFAS monitoring is particularly relevant. Our water filter guide covers activated carbon and RO options. Pull your detailed report, and visit our Washington page for statewide context.