Middlesex County, MA

ZIP 01851

In ZIP 01851, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Chelmsford Water District has 2 contaminants at or over an EPA legal limit; 9 contaminants are above health goals, led by arsenic at 327× California’s Public Health Goal.
• Nearest Superfund site: Silresim Chemical Corp., 0.4 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Tecomet (25%), mostly chromium.
• Fine particles (PM2.5) average 6.9 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 34,462 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 01851

• Superfund sites nearbyF
• Factories and industrial sitesD to F
• Oil and gas wellsA
• Parks and nature nearbyB to C
• Air qualityB
• Drinking water qualityC to F
• Pesticide useA to C
• Neighborhood health statusA to B
• Past wildfire impactsA
• Past flood impactsC
• Noise levelsB to D

Based on 8 census tracts · compiled October 25, 2026 · how each grade works and its sources

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