Mason County, WA

ZIP 98528

In ZIP 98528, 3 of the 12 things we check have at least one part graded D or F.

• Drinking water: Trails End Water District meets every EPA legal limit; 1 contaminant is above health goals, led by arsenic at 275× California’s Public Health Goal.
• Nearest Superfund site: Bremerton Gasworks, 8.6 miles away.
• Largest share of modeled toxic air from industry: US Navy Psns & Imf - Bremerton Site & Naval Base Kitsap (44%), mostly chromium.
• Fine particles (PM2.5) average 5.2 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 2,525 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 98528

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

Based on 6 census tracts · compiled October 25, 2026 · how each grade works and its sources

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