Los Angeles County, CA

ZIP 90603

In ZIP 90603, 8 of the 12 things we check have at least one part graded D or F.

• Drinking water: La Habra Heights Cwd has 2 contaminants at or over an EPA legal limit; 16 contaminants are above health goals, led by lead at 50× California’s Public Health Goal.
• Nearest Superfund site: Waste Disposal, Inc., 2.8 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Sterigenics-Ontario Facility (21%), mostly ethylene oxide.
• Fine particles (PM2.5) average 11.6 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 250,208 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 90603

• Superfund sites nearbyF
• Factories and industrial sitesF
• Oil and gas wellsF
• Parks and nature nearbyD
• Air qualityF
• Drinking water qualityD to F
• Pesticide useB to D
• Neighborhood health statusA to B
• Past wildfire impactsC to D
• Past flood impactsA
• Noise levelsA to B

Based on 6 census tracts · compiled September 10, 2026 · how each grade works and its sources

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