Charles County, MD

ZIP 20640

In ZIP 20640, 3 of the 12 things we check have at least one part graded D or F.

• Drinking water: Washington Suburban Sanitary Commission meets every EPA legal limit; 4 contaminants are above health goals, led by bromodichloromethane at 96× 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: U.S. Navy Naval Support Facility Indian Head (42%), mostly nitroglycerin.
• 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 qualityA to C
• Pesticide useC to F
• Neighborhood health statusA to F
• Past wildfire impactsA
• Past flood impactsC
• Noise levelsA
• Radiation signalsB to C

Based on 7 census tracts · compiled October 25, 2026 · how each grade works and its sources

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