Jefferson County, MT

ZIP 59635

In ZIP 59635, 6 of the 12 things we check have at least one part graded D or F.

• Drinking water: Rocky Mountain Wua has 1 contaminant at or over an EPA legal limit; 2 contaminants are above health goals, led by uranium at 1,742× 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 (92%), 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 59635

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

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

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