King County, WA

ZIP 98166

In ZIP 98166, 3 of the 12 things we check have at least one part graded D or F.

• Drinking water: Seattle Public Utilities meets every EPA legal limit; 9 contaminants are above health goals, led by pfoa at 257× California’s Public Health Goal.
• Nearest Superfund site: Seattle Municipal Landfill (kent Highlands), 4.3 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Puget Sound Coatings (50%), mostly diisocyanates.
• Fine particles (PM2.5) average 6.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 17,223 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 98166

• Superfund sites nearbyF
• Factories and industrial sitesC to D
• Oil and gas wellsB to C
• Parks and nature nearbyB to C
• Air qualityB
• Drinking water qualityC
• Pesticide useA to B
• Neighborhood health statusB to C
• Past wildfire impactsA
• Past flood impactsA
• Noise levelsA to D
• Radiation signalsA

Based on 6 census tracts · compiled October 25, 2026 · how each grade works and its sources

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