Carroll County, MD

ZIP 21158

In ZIP 21158, 6 of the 12 things we check have at least one part graded D or F.

• Drinking water: City Of Westminster meets every EPA legal limit; 10 contaminants are above health goals, led by pfos at 2.4× California’s Public Health Goal.
• Nearest Superfund site: Keystone Sanitation Landfill, 2.9 miles away.
• Largest share of modeled toxic air from industry: Kloeckner Metals Corp (57%), mostly chromium.
• Fine particles (PM2.5) average 7.7 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 164,787 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 21158

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

Based on 9 census tracts · compiled October 25, 2026 · how each grade works and its sources

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