Charles County, MD

ZIP 20640

In ZIP 20640, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Washington Suburban Sanitary Commission has 2 contaminants at or over an EPA legal limit; 20 contaminants are above health goals, led by arsenic at 274× California’s Public Health Goal.
• Nearest Superfund site: Indian Head Naval Surface Warfare Center, 2.3 miles away.
• Largest share of modeled toxic air from industry: Micron Technology Inc. (30%), mostly chlorine.
• Fine particles (PM2.5) average 7.0 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 43,120 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 20640

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

Based on 7 census tracts · compiled September 10, 2026 · how each grade works and its sources

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