Bellingham, WA vs Seattle, WA

When comparing tap water quality between Bellingham, WA and Seattle, WA, Bellingham currently holds a noticeable 11-point lead in average WaterQ score, with a score of 93 out of 100 versus 82 for Seattle. Bellingham, WA carries an A grade while Seattle, WA carries a B. A WaterQ score reflects an aggregate of EPA-reported violations, monitoring data, and compliance history across all public water systems serving each city, so a higher score generally indicates fewer recent violations and a stronger compliance record, though it does not guarantee that every tap in the city tests identically.

Seattle, WA is the larger of the two, with 1.1 million more residents than Bellingham, yet both cities are served by the same number of public water systems (6). This means the difference in population is handled by systems of different scale rather than a different count of utilities — larger systems generally serve more connections and may have more monitoring requirements under the Safe Drinking Water Act.

For residents of either Bellingham or Seattle, the most useful next step is to look up the specific water system that serves your address, since city-wide averages combine results from every system in the area. Visit the Bellingham or Seattle city pages below for a breakdown of local systems, recent violations, and contaminant-specific data, or browse WaterQ's contaminants directory to learn what each measured substance means for health.