Hays County, TX
ZIP 78666
In ZIP 78666, 6 of the 12 things we check have at least one part graded D or F.
- Drinking water: La Ventana Water Supply System meets every EPA legal limit; 8 contaminants are above health goals, led by lithium at 7.8× the USGS health-based screening level.
- 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: Structural Metals Inc (53%), mostly chromium compounds.
- Fine particles (PM2.5) average 7.9 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
- About 84,653 kg of agricultural pesticides are applied in the county each year.
Grades for ZIP 78666
- Superfund sites nearbyA
- Factories and industrial sitesA to C
- Oil and gas wellsA to D
- Parks and nature nearbyA to D
- Air qualityB to D
- Drinking water qualityB to C
- Pesticide useB to F
- Neighborhood health statusA to F
- Past wildfire impactsA
- Past flood impactsA
- Noise levelsA to D
- Radiation signalsA to C
Based on 27 census tracts · compiled October 25, 2026 · how each grade works and its sources
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