Asotin County, WA

ZIP 99401

In ZIP 99401, 3 of the 12 things we check have at least one part graded D or F.

• Drinking water: Pud #1 Of Asotin County meets every EPA legal limit; 10 contaminants are above health goals, led by lead at 78,354× 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: Clearwater Paper Corp-Ppd & Cpd Idaho (88%), mostly formaldehyde.
• Fine particles (PM2.5) average 7.1 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 24,214 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 99401

• Superfund sites nearbyA
• Factories and industrial sitesC
• Oil and gas wellsA
• Parks and nature nearbyB
• Air qualityB
• Drinking water qualityF
• Pesticide useF
• Neighborhood health statusD
• Past wildfire impactsC
• Past flood impactsA
• Noise levelsA
• Radiation signalsC

Based on 1 census tract · compiled September 10, 2026 · how each grade works and its sources

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