Orange County, CA

ZIP 92821

In ZIP 92821, 10 of the 12 things we check have at least one part graded D or F.

• Drinking water: Chino Hills, City Of has 2 contaminants at or over an EPA legal limit; 21 contaminants are above health goals, led by lead at 2,351× California’s Public Health Goal.
• Nearest Superfund site: Orange County North Basin, 5.4 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Recold (35%), mostly nickel.
• Fine particles (PM2.5) average 9.9 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 206,209 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 92821

• Superfund sites nearbyD to F
• Factories and industrial sitesF
• Oil and gas wellsF
• Parks and nature nearbyB to F
• Air qualityF
• Drinking water qualityD to F
• Pesticide useC to D
• Neighborhood health statusA to B
• Past wildfire impactsD to F
• Past flood impactsA to C
• Noise levelsA to D
• Radiation signalsC to D

Based on 12 census tracts · compiled September 10, 2026 · how each grade works and its sources

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