Hawaii Water Quality Ratings
TapWaterSafety has rated 5 public water systems in Hawaii, serving a combined 1,333,609 residents. The statewide average grade is B.
State average grade
B
Total utilities rated
5
Population served
1,333,609
Most recent test
2024
Top water quality concerns in Hawaii
- Chromium (hexavalent) significantly above health guideline
- Total trihalomethanes (TTHMs) significantly above health guideline
- Arsenic significantly above health guideline
- Perfluorohexane sulfonate (PFHXS) significantly above health guideline
- 1,2,3-Trichloropropane significantly above health guideline
Cities in Hawaii
Browse tap water quality reports by city. Click any city to see its grade, what's in the water, and recommended filters.
Grade distribution
All rated utilities in Hawaii
Sorted by score, highest first. Click any utility to see the full grade card.
| Rank | Utility | City | Population | Score | Grade |
|---|---|---|---|---|---|
| #1 | WAIPAHU-EWA-WAIANAE | WAIPAHU-EWA-WAIANAE | 217,479 | 86 | A |
| #2 | JOINT BASE PEARL HARBOR-HICKAM | PEARL HARBOR | 65,230 | 86 | A |
| #3 | HNL-WINDWARD-PEARL HARBOR | HONOLULU-WINDWARD-PEARLHARBOR | 631,389 | 85 | A |
| #4 | Honolulu Municipal Water System | Honolulu | 345,000 | 76 | B |
| #5 | WAILUKU | WAILUKU | 74,511 | 74 | C |