Derry, NH vs Dover, NH

Derry, NH and Dover, NH currently share an identical average WaterQ score, each scoring 100 out of 100. Both cities currently carry an A grade overall. Because a WaterQ score is an aggregate across all public water systems serving a city, near-identical scores can still mask differences at the system level, so residents of either city should review their specific water system's record for the most relevant detail.

Dover, NH is the larger of the two, with 11,790 more residents than Derry, yet both cities are served by the same number of public water systems (1). 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 Derry or Dover, 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 Derry or Dover 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.