San Bernardino County, CA

ZIP 91739

In ZIP 91739, 8 of the 12 things we check have at least one part graded D or F.

• Drinking water: Chino Basin Desalter Auth. - Desalter 2 has 3 contaminants at or over an EPA legal limit; 14 contaminants are above health goals, led by pfos at 15× California’s Public Health Goal.
• Nearest Superfund site: Stringfellow, 7.6 miles away (2 within 10 miles).
• Largest share of modeled toxic air from industry: Sterigenics-Ontario Facility (78%), mostly ethylene oxide.
• Fine particles (PM2.5) average 13.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 52,223 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 91739

• Superfund sites nearbyA to D
• Factories and industrial sitesB to F
• Oil and gas wellsA to C
• Parks and nature nearbyA to C
• Air qualityB to F
• Drinking water qualityA to F
• Pesticide useA
• Neighborhood health statusA to D
• Past wildfire impactsD to F
• Past flood impactsC
• Noise levelsA to D
• Radiation signalsC to F

Based on 11 census tracts · compiled October 25, 2026 · how each grade works and its sources

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