Williamstown, PA vs Bryn Mawr, PA

When comparing tap water quality between Williamstown, PA and Bryn Mawr, PA, Bryn Mawr currently holds a substantial 39-point lead in average WaterQ score, with a score of 73 out of 100 versus 34 for Williamstown. Williamstown, PA carries an F grade while Bryn Mawr, PA carries a C. 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.

Bryn Mawr, PA is the larger of the two, with 1.1 million more residents than Williamstown. Bryn Mawr is served by 14 public water systems, compared with 1 in Williamstown — a difference of 13 systems. A larger number of systems often reflects a more fragmented distribution network spanning multiple utilities, suburbs, or rural service areas, while a single large utility serving a big population can benefit from economies of scale in treatment and monitoring, but may also face more complex, aging infrastructure to maintain.

For residents of either Williamstown or Bryn Mawr, 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 Williamstown or Bryn Mawr 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.