Monroe County, MI

ZIP 48166

In ZIP 48166, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: Monroe meets every EPA legal limit; 5 contaminants are above health goals, led by pfos at 2× California’s Public Health Goal.
• Nearest Superfund site: Dsc Mclouth Steel Gibraltar Plant, 4.1 miles away (2 within 10 miles).
• Largest share of modeled toxic air from industry: Ohio Refining Co (56%), mostly cobalt compounds.
• Fine particles (PM2.5) average 7.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 242,446 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 48166

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

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

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