Alameda County, CA

ZIP 94621

In ZIP 94621, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: East Bay Mud meets every EPA legal limit; 9 contaminants are above health goals, led by pfos at 1.4× California’s Public Health Goal.
• Nearest Superfund site: Alameda Naval Air Station, 4.9 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Pcc Structurals-San Leandro (28%), mostly cobalt.
• Fine particles (PM2.5) average 8.9 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 57,837 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 94621

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

Based on 13 census tracts · compiled October 25, 2026 · how each grade works and its sources

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