Suffolk County, NY

ZIP 11720

In ZIP 11720, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Suffolk County Water Authority has 2 contaminants at or over an EPA legal limit; 17 contaminants are above health goals, led by pfos at 6.2× California’s Public Health Goal.
• Nearest Superfund site: Bioclinical Laboratories, Inc., 4.3 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Long Island Sterilization (26%), mostly ethylene oxide.
• Fine particles (PM2.5) average 6.7 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 167,580 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 11720

• Superfund sites nearbyD to F
• Factories and industrial sitesB
• Oil and gas wellsA
• Parks and nature nearbyD to F
• Air qualityA to B
• Drinking water qualityF
• Pesticide useC
• Neighborhood health statusA to C
• Past wildfire impactsA
• Past flood impactsD
• Noise levelsA to C
• Radiation signalsB

Based on 11 census tracts · compiled September 10, 2026 · how each grade works and its sources

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