Oregon Tap Water Quality
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Overview
Portland drinks from the Bull Run watershed, a federally protected forest reserve closed to the public since 1904, one of America's premier municipal sources. A 2017 cryptosporidium detection ended its filtration waiver, and the city's new filtration plant (due 2027) is its largest-ever infrastructure project; water remains safe and compliant meanwhile.
Salem's 2018 algal-toxin advisory from Detroit Lake pushed bloom monitoring statewide, and Eugene's McKenzie River supply is among the cleanest anywhere. East of the Cascades, agricultural nitrate in the Lower Umatilla Basin has left rural well users with the state's most serious ongoing contamination problem.
Common Contaminants in Oregon
Low-level Bull Run detections triggered Portland's filtration mandate; UV and the new plant close the gap
Cascade reservoir blooms (Detroit Lake) require seasonal monitoring for Salem and neighbors
The Lower Umatilla Basin's groundwater exceeds limits under decades of farm and food-processing load; a declared emergency for private well users
Violations & Compliance
The big western systems comply fully. The state's hardest problem is the Umatilla Basin nitrate emergency affecting rural wells, where bottled water and treatment programs are still scaling.
City Water Reports in Oregon
Frequently Asked Questions
Sources & References
The safety rating and guidance on this page draw on the following sources. See our full methodology.
- •US EPA Safe Drinking Water Act regulations
- •EWG Tap Water Database
- •The utility's most recent Consumer Confidence Report (CCR)
- •WHO Guidelines for Drinking-water Quality