Marin County, CA

ZIP 94939

In ZIP 94939, 2 of the 12 things we check have at least one part graded D or F.

• Drinking water: Marin Municipal Water District meets every EPA legal limit; 10 contaminants are above health goals, led by pfos at 1.2× California’s Public Health Goal.
• Nearest Superfund site: United Heckathorn Co., 6.7 miles away (2 within 10 miles).
• Largest share of modeled toxic air from industry: Chevron Products Co Richmond Refinery (48%), mostly acrylamide.
• Fine particles (PM2.5) average 7.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 3,141 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 94939

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

Based on 5 census tracts · compiled October 25, 2026 · how each grade works and its sources

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