Boulder County, CO

ZIP 80504

In ZIP 80504, 9 of the 12 things we check have at least one part graded D or F.

• Drinking water: Fox Hill Water Association Inc meets every EPA legal limit; 2 contaminants are above health goals, led by arsenic at 375× California’s Public Health Goal.
• 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: Arc Colorado Inc. (75%), mostly trichloroethylene.
• Fine particles (PM2.5) average 7.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 542,391 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 80504

• Superfund sites nearbyA
• Factories and industrial sitesB to D
• Oil and gas wellsD to F
• Parks and nature nearbyC to F
• Air qualityA to C
• Drinking water qualityC to D
• Pesticide useC to F
• Neighborhood health statusA to C
• Past wildfire impactsA to D
• Past flood impactsA to F
• Noise levelsA to D
• Radiation signalsF

Based on 23 census tracts · compiled September 10, 2026 · how each grade works and its sources

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