Washington County, MN

ZIP 55090

In ZIP 55090, 4 of the 12 things we check have at least one part graded D or F.

• Drinking water: Mahtomedi meets every EPA legal limit; 7 contaminants are above health goals, led by arsenic at 150× California’s Public Health Goal.
• Nearest Superfund site: Oakdale Dump, 4.7 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Andersen Corp (28%), mostly cobalt compounds.
• Fine particles (PM2.5) average 7.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 49,911 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 55090

• Superfund sites nearbyD
• Factories and industrial sitesC
• Oil and gas wellsA
• Parks and nature nearbyC
• Air qualityC
• Drinking water qualityC to D
• Pesticide useD
• Neighborhood health statusC
• Past wildfire impactsA
• Past flood impactsA
• Noise levelsA
• Radiation signalsD

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

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