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 C.

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
State average grade
C
71/100
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.

HONOLULU-WINDWARD-PEARLHARBOR
C 631,389
Honolulu
D 345,000
PEARL HARBOR
B 65,230
WAILUKU
D 74,511
WAIPAHU-EWA-WAIANAE
C 217,479

Grade distribution

A
0 (0%)
B
1 (20%)
C
3 (60%)
D
1 (20%)
F
0 (0%)

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 JOINT BASE PEARL HARBOR-HICKAM PEARL HARBOR 65,230 80 B
#2 WAIPAHU-EWA-WAIANAE WAIPAHU-EWA-WAIANAE 217,479 74 C
#3 HNL-WINDWARD-PEARL HARBOR HONOLULU-WINDWARD-PEARLHARBOR 631,389 72 C
#4 WAILUKU WAILUKU 74,511 67 C
#5 Honolulu Municipal Water System Honolulu 345,000 64 D