Contra Costa County, CA

ZIP 94548

In ZIP 94548, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Diablo Water District meets every EPA legal limit; 14 contaminants are above health goals, led by arsenic at 893× California’s Public Health Goal.
• Closer to Superfund sites than 0% of U.S. neighborhoods, with no listed site within 10 miles of its center.
• Largest share of modeled toxic air from industry: Owens-Brockway Glass Container Inc Plant #22 (50%), mostly chromium compounds.
• Fine particles (PM2.5) average 8.4 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 98,092 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 94548

• Superfund sites nearbyA
• Factories and industrial sitesB
• Oil and gas wellsD
• Parks and nature nearbyC
• Air qualityD
• Drinking water qualityC to D
• Pesticide useF
• Neighborhood health statusA
• Past wildfire impactsA
• Past flood impactsB
• Noise levelsA
• Radiation signalsC

Based on 1 census tract · compiled September 10, 2026 · how each grade works and its sources

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