New London County, CT

ZIP 06340

In ZIP 06340, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Groton Utilities meets every EPA legal limit; 8 contaminants are above health goals, led by lead at 116× California’s Public Health Goal.
• Nearest Superfund site: New London Submarine Base, 0.2 miles away.
• Largest share of modeled toxic air from industry: Doncasters Inc Precision Castings New England (62%), mostly cobalt.
• Fine particles (PM2.5) average 5.6 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 21,460 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 06340

• Superfund sites nearbyD to F
• Factories and industrial sitesC to F
• Oil and gas wellsA
• Parks and nature nearbyB to C
• Air qualityA
• Drinking water qualityB to F
• Pesticide useC
• Neighborhood health statusA to C
• Past wildfire impactsA
• Past flood impactsC
• Noise levelsA to F

Based on 10 census tracts · compiled October 25, 2026 · how each grade works and its sources

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