Contra Costa County, CA

ZIP 94506

In ZIP 94506, 3 of the 12 things we check have at least one part graded D or F.

• Drinking water: Doubletree Ranch Water System has 1 contaminant at or over an EPA legal limit; 3 contaminants are above health goals, led by arsenic at 8,485× California’s Public Health Goal.
• Closer to Superfund sites than 55% of U.S. neighborhoods, with no listed site within 10 miles of its center.
• Largest share of modeled toxic air from industry: Tesla Inc. (22%), mostly cobalt compounds.
• Fine particles (PM2.5) average 7.3 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 94506

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

Based on 7 census tracts · compiled October 25, 2026 · how each grade works and its sources

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