Napa County, CA

ZIP 94574

In ZIP 94574, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: Loch Haven Mutual Water Company has 1 contaminant at or over an EPA legal limit; 6 contaminants are above health goals, led by arsenic at 2,587× California’s Public Health Goal.
• Closer to Superfund sites than 56% of U.S. neighborhoods, with no listed site within 10 miles of its center.
• Largest share of modeled toxic air from industry: Ardagh Metal Beverage USA Inc Re: Fairfield Plant (28%), mostly certain glycol ethers.
• Fine particles (PM2.5) average 7.0 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 906,696 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 94574

• Superfund sites nearbyA to C
• Factories and industrial sitesA to C
• Oil and gas wellsA
• Parks and nature nearbyA to D
• Air qualityB
• Drinking water qualityB to D
• Pesticide useD to F
• Neighborhood health statusB to D
• Past wildfire impactsF
• Past flood impactsA
• Noise levelsA to B
• Radiation signalsA to C

Based on 8 census tracts · compiled October 25, 2026 · how each grade works and its sources

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