Allegany County, MD

ZIP 21557

In ZIP 21557, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: Piedmont Municipal Wtr Wks meets every EPA legal limit; 8 contaminants are above health goals, led by arsenic at 363× California’s Public Health Goal.
• Nearest Superfund site: Allegany Ballistics Laboratory (usnavy), 2.0 miles away (2 within 10 miles).
• Largest share of modeled toxic air from industry: Aes Warrior Run Inc (56%), mostly arsenic compounds.
• Fine particles (PM2.5) average 7.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 16,147 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 21557

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

Based on 2 census tracts · compiled October 25, 2026 · how each grade works and its sources

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