Riverside County, CA

ZIP 92373

In ZIP 92373, 10 of the 12 things we check have at least one part graded D or F.

• Drinking water: Riverside Highland Water Company has 2 contaminants at or over an EPA legal limit; 18 contaminants are above health goals, led by pfos at 18× California’s Public Health Goal.
• Nearest Superfund site: Norton Air Force Base (lndfll #2), 2.3 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Sterigenics-Ontario Facility (50%), mostly ethylene oxide.
• Fine particles (PM2.5) average 9.5 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 1,172,577 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 92373

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

Based on 14 census tracts · compiled September 10, 2026 · how each grade works and its sources

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