Lewis and Clark County, MT

ZIP 59602

In ZIP 59602, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: Moonlight Estates Hoa meets every EPA legal limit; 3 contaminants are above health goals, led by arsenic at 700× California’s Public Health Goal.
• Nearest Superfund site: East Helena Site, 6.4 miles away.
• Largest share of modeled toxic air from industry: American Chemet Corp (97%), mostly copper compounds.
• Fine particles (PM2.5) average 5.7 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 26,812 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 59602

• Superfund sites nearbyC to F
• Factories and industrial sitesA to B
• Oil and gas wellsA
• Parks and nature nearbyA to C
• Air qualityA
• Drinking water qualityA to C
• Pesticide useC to F
• Neighborhood health statusB to D
• Past wildfire impactsA to D
• Past flood impactsA
• Noise levelsA to C
• Radiation signalsD to F

Based on 10 census tracts · compiled October 25, 2026 · how each grade works and its sources

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