Northwest Arctic County, AK

ZIP 99770

In ZIP 99770, 2 of the 12 things we check have at least one part graded D or F.

• Drinking water: Kobuk Water System has 1 contaminant at or over an EPA legal limit; 5 contaminants are above health goals, led by arsenic at 3,856× 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: Red Dog Operations (100%), mostly chromium compounds.
• Fine particles (PM2.5) average 3.7 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.

Grades for ZIP 99770

• Superfund sites nearbyA
• Factories and industrial sitesA
• Oil and gas wellsA
• Air qualityA
• Drinking water qualityC to F
• Neighborhood health statusD
• Past wildfire impactsA
• Past flood impactsA

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

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