Humboldt County, CA

ZIP 95558

In ZIP 95558, 2 of the 12 things we check have at least one part graded D or F.

• Drinking water: Del Oro Water Co-Ferndale has 3 contaminants at or over an EPA legal limit; 18 contaminants are above health goals, led by pfda at 30× Preliminary Research (Under Review).
• 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: Pg&E Humboldt Bay Power Plant (100%), mostly acetaldehyde.
• Fine particles (PM2.5) average 7.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 15,274 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 95558

• Superfund sites nearbyA
• Factories and industrial sitesB
• Oil and gas wellsB
• Parks and nature nearbyC
• Air qualityC
• Drinking water qualityA to F
• Pesticide useC
• Neighborhood health statusD
• Past wildfire impactsA
• Past flood impactsA
• Noise levelsA
• Radiation signalsC

Based on 1 census tract · compiled September 10, 2026 · how each grade works and its sources

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