Grant County, SD

ZIP 57266

In ZIP 57266, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Milbank meets every EPA legal limit; 4 contaminants are above health goals, led by arsenic at 250× 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: Poet Biorefining-Big Stone LLC (44%), mostly acrolein.
• Fine particles (PM2.5) average 6.0 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 242,220 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 57266

• Superfund sites nearbyA
• Factories and industrial sitesA
• Oil and gas wellsA
• Parks and nature nearbyC
• Air qualityA
• Drinking water qualityA to D
• Pesticide useF
• Neighborhood health statusC to F
• Past wildfire impactsA
• Past flood impactsA
• Noise levelsA
• Radiation signalsD

Based on 2 census tracts · compiled October 25, 2026 · how each grade works and its sources

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