Portland OR metro: water quality. Portland draws its drinking water from the Bull Run Watershed, a 102-square-mile protected area in the Mt.
Portland draws its drinking water from the Bull Run Watershed, a 102-square-mile protected area in the Mt. Hood National Forest that has been closed to public entry since 1904. This gives the city one of the few unfiltered surface water supplies in the country – the water is so clean at the source that the EPA granted Portland a filtration exemption. UV treatment was added in 2014 as an additional safeguard. The Portland Water Bureau serves about 1 million people in the city and surrounding areas.
Beyond Portland, the metro looks different. Eugene operates its own system from the McKenzie River. Salem draws from the North Santiam River. Beaverton purchases from Portland or the Joint Water Commission. Across 2.5 million residents, the metro spans the Willamette Valley and includes communities with very different water infrastructure.
Portland's Bull Run supply has shown very low PFAS levels in UCMR5 testing – consistent with a remote, protected watershed with no industrial or military activity. The metro's PFAS concerns center on other locations.
The Portland Air National Guard Base (PANGB) at Portland International Airport has confirmed PFAS contamination from AFFF use. The Oregon Department of Environmental Quality (DEQ) has been investigating the site, and groundwater contamination has been documented in the Columbia South Shore area near the airport. Kingsley Field Air National Guard Base in Klamath Falls is another Oregon site with confirmed contamination, though it falls outside the metro boundary.
Oregon adopted health advisory levels for drinking water in 2021, setting a combined limit of 30 ppt for PFOA, PFOS, and three other PFAS compounds. According to Oregon DEQ data, four community water systems in the Portland metro reported detections above state advisory levels, all in the east metro near the airport.
Portland's Bull Run source puts it in the top tier of American municipal water supplies – alongside Seattle, San Francisco, and New York's reservoir systems. The protected watershed model works, and Portland has benefited from it for over a century.
The pattern within the metro mirrors what other West Coast cities experience: clean core supply, localized military or industrial contamination near the edges. Eugene's McKenzie River supply is similarly clean; Salem's North Santiam system has occasionally faced turbidity issues from wildfire impacts but tests low for PFAS.
Visit our Oregon state page for statewide data.
Portland city residents on Bull Run water have minimal PFAS risk from their supply. If you live near Portland International Airport or in the Columbia South Shore area, the picture is different.
Check your water to confirm your provider and see current monitoring data. For east metro residents near known PFAS sites, filtering makes sense as a precaution while cleanup proceeds. Our water filter guide covers appropriate options. A detailed report can show whether contamination in your area is stable or shifting.