Contra Costa County, CA

ZIP 94521

In ZIP 94521, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: City Of Pittsburg meets every EPA legal limit; 12 contaminants are above health goals, led by arsenic at 744× California’s Public Health Goal.
• Nearest Superfund site: Concord Naval Weapons Station, 5.9 miles away.
• Largest share of modeled toxic air from industry: Shell Catalysts & Technologies - Pittsburg (48%), mostly cobalt compounds.
• Fine particles (PM2.5) average 8.7 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 94521

• Superfund sites nearbyD to F
• Factories and industrial sitesC to F
• Oil and gas wellsA to D
• Parks and nature nearbyA to C
• Air qualityC to F
• Drinking water qualityC
• Pesticide useB to C
• Neighborhood health statusA to B
• Past wildfire impactsA to C
• Past flood impactsA to B
• Noise levelsA to C
• Radiation signalsC

Based on 14 census tracts · compiled October 25, 2026 · how each grade works and its sources

Loading the full report, with every source…