Johnson County, TN

ZIP 37640

In ZIP 37640, 3 of the 12 things we check have at least one part graded D or F.

• Drinking water: Siam Utility District meets every EPA legal limit; 2 contaminants are above health goals, led by total haloacetic acids (haa5) at 2.3× Peer-Reviewed Research.
• 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: Snap-On Tools Co (80%), mostly nickel.
• Fine particles (PM2.5) average 5.9 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 10,486 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 37640

• Superfund sites nearbyA
• Factories and industrial sitesB to C
• Oil and gas wellsA
• Parks and nature nearbyA to C
• Air qualityA
• Drinking water qualityA to B
• Pesticide useB to D
• Neighborhood health statusF
• Past wildfire impactsA
• Past flood impactsB
• Noise levelsA
• Radiation signalsB to F

Based on 3 census tracts · compiled October 25, 2026 · how each grade works and its sources

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