Decatur County, IA

ZIP 50140

In ZIP 50140, 6 of the 12 things we check have at least one part graded D or F.

• Drinking water: Mount Ayr Water Treatment Plant meets every EPA legal limit; 8 contaminants are above health goals, led by lead at 16× California’s Public Health Goal.
• Closer to Superfund sites than 0% of U.S. neighborhoods, with no listed site within 10 miles of its center.
• Largest share of modeled toxic air from industry: Central Iowa Ready Mix Mt. Ayr (72%), mostly lead.
• Fine particles (PM2.5) average 6.5 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 129,925 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 50140

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

Based on 3 census tracts · compiled September 10, 2026 · how each grade works and its sources

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