San Mateo County, CA

ZIP 94025

In ZIP 94025, 6 of the 12 things we check have at least one part graded D or F.

• Drinking water: Santa Clara Valley Water District meets every EPA legal limit; 14 contaminants are above health goals, led by pfos at 3.7× California’s Public Health Goal.
• Nearest Superfund site: Hewlett-Packard (620-640 Page Mill Road), 3.0 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Tesla Inc. (86%), mostly cobalt compounds.
• Fine particles (PM2.5) average 8.8 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 94025

• Superfund sites nearbyD to F
• Factories and industrial sitesB to C
• Oil and gas wellsA
• Parks and nature nearbyC to F
• Air qualityA to F
• Drinking water qualityD to F
• Pesticide useC to D
• Neighborhood health statusA to B
• Past wildfire impactsA
• Past flood impactsA
• Noise levelsA to D
• Radiation signalsC

Based on 14 census tracts · compiled September 10, 2026 · how each grade works and its sources

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