Cascade County, MT

ZIP 59401

In ZIP 59401, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: Great Falls City Of meets every EPA legal limit; 11 contaminants are above health goals, led by lithium at 6.9× the USGS health-based screening level.
• Nearest Superfund site: Acm Smelter and Refinery, 2.2 miles away.
• Largest share of modeled toxic air from industry: Calumet Montana Refining LLC. (100%), mostly benzene.
• Fine particles (PM2.5) average 6.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 153,341 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 59401

• Superfund sites nearbyF
• Factories and industrial sitesB to C
• Oil and gas wellsA
• Parks and nature nearbyB to C
• Air qualityB
• Drinking water qualityC
• Pesticide useD to F
• Neighborhood health statusC to F
• Past wildfire impactsA
• Past flood impactsA
• Noise levelsA to D
• Radiation signalsF

Based on 8 census tracts · compiled October 25, 2026 · how each grade works and its sources

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