Water Quality · Hawaii
Best Water Quality Counties in Hawaii 2026
Ranked by EPA drinking water health violations.
Top 10 — Water Quality in Hawaii
Score reflects water quality only — not overall county quality.
All Hawaii Counties — Water Quality Rankings
4 counties ranked by water quality score. Overall Score shown for context.
| # | County | Water Quality Score | Overall Score |
|---|---|---|---|
| 1 | Kauai County, HI | 86 | 50.2 |
| 2 | Maui County, HI | 86 | 46.4 |
| 3 | Honolulu County, HI | 71.9 | 47.5 |
| 4 | Hawaii County, HI | 70.6 | 47.5 |