Okanogan County, WA

ZIP 99116

In ZIP 99116, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: Mansfield Water System has 1 contaminant at or over an EPA legal limit; 10 contaminants are above health goals, led by pfos at 15× California’s Public Health Goal.
• Closer to Superfund sites than 0% of U.S. neighborhoods, with no listed site within 10 miles of its center.
• Largest share of modeled toxic air from industry: Sgl Composites LLC (92%), mostly hydrogen cyanide.
• Fine particles (PM2.5) average 7.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 813,147 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 99116

• Superfund sites nearbyA
• Factories and industrial sitesA to B
• Oil and gas wellsA
• Parks and nature nearbyB to C
• Air qualityB to C
• Drinking water qualityC to F
• Pesticide useF
• Neighborhood health statusD to F
• Past wildfire impactsC to F
• Past flood impactsA
• Noise levelsA
• Radiation signalsD

Based on 3 census tracts · compiled September 10, 2026 · how each grade works and its sources

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