Monroe County, WI

ZIP 54660

In ZIP 54660, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Ontario Waterworks meets every EPA legal limit; 6 contaminants are above health goals, led by arsenic at 108× California’s Public Health Goal.
• Nearest Superfund site: Tomah Armory, 0.7 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Wabash (Walker Stainless Equipment Co) (34%), mostly chromium.
• Fine particles (PM2.5) average 6.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 84,544 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 54660

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

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

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