San Bernardino County, CA

ZIP 91786

In ZIP 91786, 6 of the 12 things we check have at least one part graded D or F.

• Drinking water: San Antonio Water Company has 1 contaminant at or over an EPA legal limit; 12 contaminants are above health goals, led by pfos at 3.2× California’s Public Health Goal.
• Closer to Superfund sites than 0% of U.S. neighborhoods, with no listed site within 10 miles of its center.
• Largest share of modeled toxic air from industry: Sterigenics-Ontario Facility (73%), mostly ethylene oxide.
• Fine particles (PM2.5) average 12.7 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 91786

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

Based on 14 census tracts · compiled October 25, 2026 · how each grade works and its sources

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