Boulder County, CO

ZIP 80503

In ZIP 80503, 8 of the 12 things we check have at least one part graded D or F.

• Drinking water: Olde Stage Wd meets every EPA legal limit; 11 contaminants are above health goals, led by pfos at 2.1× California’s Public Health Goal.
• Nearest Superfund site: Marshall Landfill, 9.0 miles away.
• Largest share of modeled toxic air from industry: Terumo Bct Sterilization Services Inc (85%), mostly ethylene oxide.
• Fine particles (PM2.5) average 7.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 63,666 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 80503

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

Based on 12 census tracts · compiled September 10, 2026 · how each grade works and its sources

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