Harris County, TX

ZIP 77521

In ZIP 77521, 9 of the 12 things we check have at least one part graded D or F.

• Drinking water: Tower Terrace meets every EPA legal limit; 8 contaminants are above health goals, led by bromodichloromethane at 334× California’s Public Health Goal.
• Nearest Superfund site: San Jacinto River Waste Pits, 3.2 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Equistar Chemicals Bayport Chemicals Plant (43%), mostly ethylene oxide.
• Fine particles (PM2.5) average 8.9 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 69,664 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 77521

• Superfund sites nearbyA to F
• Factories and industrial sitesF
• Oil and gas wellsD to F
• Parks and nature nearbyC to D
• Air qualityC to F
• Drinking water qualityB to F
• Pesticide useA to F
• Neighborhood health statusA to D
• Past wildfire impactsA
• Past flood impactsC
• Noise levelsA to D
• Radiation signalsA

Based on 16 census tracts · compiled October 25, 2026 · how each grade works and its sources

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