San Mateo County, CA
ZIP 94402
In ZIP 94402, 6 of the 12 things we check have at least one part graded D or F.
- Drinking water: California Water Service - Bear Gulch has 1 contaminant at or over an EPA legal limit; 14 contaminants are above health goals, led by pfos at 7.8× 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: Tesla Inc. (58%), mostly cobalt compounds.
- Fine particles (PM2.5) average 7.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
- About 38,964 kg of agricultural pesticides are applied in the county each year.
Grades for ZIP 94402
- Superfund sites nearbyA
- Factories and industrial sitesB to D
- Oil and gas wellsA to F
- Parks and nature nearbyA to D
- Air qualityA to C
- Drinking water qualityC to D
- Pesticide useB to D
- Neighborhood health statusA to B
- Past wildfire impactsA
- Past flood impactsA
- Noise levelsA to D
- Radiation signalsB to C
Based on 12 census tracts · compiled October 25, 2026 · how each grade works and its sources
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