Hawaii public water systems
137 active systems regulated under the Safe Drinking Water Act, serving a reported 1.5M people across 5 counties.
Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.
Active systems
137
Population served
1.5M
Community systems
119
Groundwater share
92.7%
System types in Hawaii
119
Community water system
15
Non-transient non-community water system
3
Transient non-community water system
Largest water systems in Hawaii
| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | Hnl-Windward-Pearl Harbor | Honolulu | 631,389 | Community | Groundwater |
| 2 | Waipahu-Ewa-Waianae | Honolulu | 217,479 | Community | Groundwater |
| 3 | Wailuku | Maui | 74,511 | Community | Surface water |
| 4 | Joint Base Pearl Harbor-Hickam | Honolulu | 65,230 | Community | Groundwater |
| 5 | Mililani | Honolulu | 50,573 | Community | Groundwater |
| 6 | Hilo | Hawaii | 39,477 | Community | Groundwater |
| 7 | Schofield Barracks | Honolulu | 37,920 | Community | Groundwater |
| 8 | Lihue-Kapaa | Kauai | 34,854 | Community | Surface water |
| 9 | Makawao | Maui | 29,868 | Community | Surface water |
| 10 | North Kona | Hawaii | 29,581 | Community | Groundwater |
| 11 | Wahiawa | Honolulu | 23,348 | Community | Groundwater |
| 12 | Lahaina | Maui | 20,065 | Community | Surface water |
| 13 | Marine Corps Base Hawaii | Honolulu | 16,300 | Community | Purchased groundwater |
| 14 | Kalaheo-Koloa | Kauai | 12,660 | Community | Groundwater |
| 15 | Waikoloa | Hawaii | 12,100 | Community | Groundwater |
| 16 | Waipio Heights | Honolulu | 11,516 | Community | Groundwater |
| 17 | Waialua-Haleiwa | Honolulu | 9,996 | Community | Groundwater |
| 18 | South Kohala | Hawaii | 9,612 | Community | Surface water |
| 19 | Kaanapali | Maui | 8,000 | Community | Groundwater |
| 20 | Upper Kula | Maui | 7,686 | Community | Surface water |
| 21 | Fort Shafter | Honolulu | 7,067 | Community | Groundwater |
| 22 | Princeville | Kauai | 6,911 | Community | Groundwater |
| 23 | South Kona | Hawaii | 6,512 | Community | Groundwater |
| 24 | Nctams Eastpac | Honolulu | 6,470 | Community | Groundwater |
| 25 | Olaa-Mountain View | Hawaii | 6,467 | Community | Groundwater |