Water Quality · Massachusetts
Best Water Quality Counties in Massachusetts 2026
Ranked by EPA drinking water health violations.
Top 10 — Water Quality in Massachusetts
Score reflects water quality only — not overall county quality.
All Massachusetts Counties — Water Quality Rankings
14 counties ranked by water quality score. Overall Score shown for context.
| # | County | Water Quality Score | Overall Score |
|---|---|---|---|
| 1 | Dukes County, MA | 86 | 61.3 |
| 2 | Nantucket County, MA | 86 | 55.7 |
| 3 | Suffolk County, MA | 86 | 43 |
| 4 | Barnstable County, MA | 71.5 | 58 |
| 5 | Essex County, MA | 70.4 | 48.3 |
| 6 | Middlesex County, MA | 68 | 50.7 |
| 7 | Hampshire County, MA | 67.5 | 49.4 |
| 8 | Hampden County, MA | 66.4 | 32.8 |
| 9 | Plymouth County, MA | 64.5 | 48.7 |
| 10 | Norfolk County, MA | 63.8 | 51 |
| 11 | Worcester County, MA | 63.5 | 46.8 |
| 12 | Berkshire County, MA | 60.6 | 44.1 |
| 13 | Bristol County, MA | 60.4 | 45 |
| 14 | Franklin County, MA | 53.4 | 46.2 |