Riverside County, CA

ZIP 92521

In ZIP 92521, 7 of the 12 things we check have at least one part graded D or F.

• Drinking water: Riverside, City Of has 2 contaminants at or over an EPA legal limit; 18 contaminants are above health goals, led by pfhxs at 1.8× California Notification Level.
• Nearest Superfund site: Alark Hard Chrome, 2.6 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Sterigenics-Ontario Facility (65%), mostly ethylene oxide.
• Fine particles (PM2.5) average 10.9 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 92521

• Superfund sites nearbyF
• Factories and industrial sitesF
• Oil and gas wellsB
• Parks and nature nearbyC
• Air qualityF
• Drinking water qualityF
• Pesticide useC to D
• Neighborhood health statusA to B
• Past wildfire impactsC
• Past flood impactsC
• Noise levelsB to D
• Radiation signalsB to D

Based on 2 census tracts · compiled October 25, 2026 · how each grade works and its sources

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