Jefferson County, MT

ZIP 59634

In ZIP 59634, 6 of the 12 things we check have at least one part graded D or F.

• Drinking water: Hangmans Tree Wua has 1 contaminant at or over an EPA legal limit; 5 contaminants are above health goals, led by arsenic at 3,438× California’s Public Health Goal.
• Nearest Superfund site: Basin Mining Area, 5.7 miles away.
• Largest share of modeled toxic air from industry: American Chemet Corp (60%), mostly copper compounds.
• Fine particles (PM2.5) average 5.2 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 10,384 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 59634

• Superfund sites nearbyD to F
• Factories and industrial sitesA to B
• Oil and gas wellsA
• Parks and nature nearbyB
• Air qualityA
• Drinking water qualityD to F
• Pesticide useD to F
• Neighborhood health statusC to D
• Past wildfire impactsC to D
• Past flood impactsA
• Noise levelsA to C
• Radiation signalsF

Based on 2 census tracts · compiled September 10, 2026 · how each grade works and its sources

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