St. Charles County, MO
ZIP 63304
In ZIP 63304, 7 of the 12 things we check have at least one part graded D or F.
- Drinking water: St Charles County Pwsd 2 has 1 contaminant at or over an EPA legal limit; 17 contaminants are above health goals, led by nitrite at 15× https://pmc.ncbi.nlm.nih.gov/articles/PMC4535738/.
- Nearest Superfund site: Weldon Spring Quarry/plant/pits (usdoe/army), 0.5 miles away (3 within 10 miles).
- Largest share of modeled toxic air from industry: Wood River Refinery (32%), mostly chromium compounds.
- Fine particles (PM2.5) average 8.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
- About 138,436 kg of agricultural pesticides are applied in the county each year.
Grades for ZIP 63304
- Superfund sites nearbyA to F
- Factories and industrial sitesB to D
- Oil and gas wellsA to B
- Parks and nature nearbyC to F
- Air qualityD to F
- Drinking water qualityC to D
- Pesticide useD to F
- Neighborhood health statusB to C
- Past wildfire impactsA
- Past flood impactsA
- Noise levelsA to C
- Radiation signalsC to D
Based on 15 census tracts · compiled September 10, 2026 · how each grade works and its sources
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