Pierce County, Washington: drinking water report. Pierce County – Tacoma and its surrounding communities – serves about 920,000 residents.
Pierce County – Tacoma and its surrounding communities – serves about 920,000 residents. Tacoma Water draws from the Green River and a system of wells tapping glacial aquifers fed by rainfall and snowmelt from Mount Rainier. Smaller suburban systems operate independently, some purchasing wholesale from Tacoma and others running their own wells. The region's abundant rainfall keeps supply ample, but the geology beneath the county creates varied groundwater quality.
The Green River watershed is largely forested and provides clean source water for Tacoma's surface supply. Groundwater quality varies more. Joint Base Lewis-McChord (JBLM), one of the largest military installations on the West Coast, sits in the southern part of the county and is a confirmed PFAS source from AFFF firefighting foam use. The Washington Department of Ecology has documented PFAS contamination in monitoring wells near the base.
According to the Washington DOE's 2024 PFAS investigation, several community water systems in the JBLM vicinity reported PFAS above the state's action level of 10 ppt for individual compounds. UCMR5 data confirms detections in six public water systems countywide.
If your water comes from Tacoma's Green River supply, your baseline is strong. Communities near JBLM should pay closer attention to PFAS data.
Check your water to see monitoring results for your specific area. For PFAS, activated carbon or reverse osmosis filters work at the household level. Our water filter guide details which certifications matter. Pull your detailed report, and visit our Washington page for statewide context.