Los Angeles County, CA

ZIP 91331

In ZIP 91331, 9 of the 12 things we check have at least one part graded D or F.

• Drinking water: San Fernando-City, Water Dept. meets every EPA legal limit; 12 contaminants are above health goals, led by arsenic at 223× California’s Public Health Goal.
• Nearest Superfund site: San Fernando Valley (area 1), 4.8 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Sterigenics US LLC La 50Th (26%), mostly ethylene oxide.
• Fine particles (PM2.5) average 10.6 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 91331

• Superfund sites nearbyF
• Factories and industrial sitesF
• Oil and gas wellsC to F
• Parks and nature nearbyA to D
• Air qualityD to F
• Drinking water qualityC
• Pesticide useB
• Neighborhood health statusA to D
• Past wildfire impactsD to F
• Past flood impactsA
• Noise levelsA to D
• Radiation signalsD

Based on 37 census tracts · compiled October 25, 2026 · how each grade works and its sources

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