Dewey County, SD

ZIP 57661

In ZIP 57661, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Isabel meets every EPA legal limit; 2 contaminants are above health goals, led by lead at 21× California’s Public Health Goal.
• 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: Ring-Neck Energy & Feed LLC (100%), mostly acetaldehyde.
• Fine particles (PM2.5) average 5.6 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 57,669 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 57661

• Superfund sites nearbyA
• Factories and industrial sitesA
• Oil and gas wellsA
• Parks and nature nearbyC
• Air qualityA
• Drinking water qualityC to D
• Pesticide useF
• Neighborhood health statusD
• Noise levelsA
• Radiation signalsD

Based on 1 census tract · compiled September 10, 2026 · how each grade works and its sources

Loading the full report, with every source…