Hawaii
Honolulu County drinking water quality
38 active public water systems serve 1,128,119 people in Honolulu County. 32 are compliant, 6 had at least one EPA violation in the past three years, 0 are designated serious violators, and 0 carry a health flag.
Community water systems
30 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Hnl-Windward-Pearl Harbor Honolulu-windward-pearlharbor |
631,389 | 0 | 0 | |
|
Waipahu-Ewa-Waianae Waipahu-ewa-waianae |
217,479 | 0 | 0 | |
|
Joint Base Pearl Harbor-Hickam Pearl Harbor |
65,230 | 1 | 1 | |
|
Mililani Mililani Bws |
50,573 | 0 | 0 | |
|
Schofield Barracks |
37,920 | 0 | 0 | |
|
Wahiawa |
23,348 | 0 | 0 | |
|
Marine Corps Base Hawaii Kaneohe |
16,300 | 1 | 0 | |
|
Waipio Heights Waipio |
11,516 | 0 | 0 | |
|
Waialua-Haleiwa Waialua-haleiwa |
9,996 | 0 | 0 | |
|
Fort Shafter |
7,067 | 0 | 0 | |
|
Nctams Eastpac Wahiawa |
6,470 | 0 | 0 | |
|
Aliamanu Salt Lake |
6,406 | 1 | 1 | |
|
Laie Water Company Laie |
5,577 | 0 | 0 | |
|
Tripler Army Medical Cntr Moanalua |
5,555 | 0 | 0 | |
|
Barbers Point Waipahu-ewa-waianae |
5,256 | 0 | 0 | |
|
Waialee-Sunset Beach Sunset Beach |
4,916 | 0 | 0 | |
|
Kamehameha Schools Kapalama |
4,000 | 0 | 0 | |
|
The Queen's Medical Center Downtown Honolulu |
3,440 | 0 | 0 | |
|
Kahuku Kahuku |
2,730 | 0 | 0 | |
|
Dillingham Airfield Mokuleia |
1,800 | 0 | 0 | |
|
Kunia Village Wahiawa |
650 | 0 | 0 | |
|
Camp Stover Wahiawa |
595 | 0 | 0 | |
|
Waiawa Correctional Facility Waipahu |
444 | 0 | 0 | |
|
Waialua Sugar Pump 2 Waialua-haleiwa |
400 | 0 | 0 | |
|
Waiahole Kahana Valley |
300 | 0 | 0 | |
|
Dillingham Ranch Waialua-haleiwa |
100 | 0 | 0 | |
|
Kahuku Air Base Kahuku Air Base |
75 | 0 | 0 | |
|
Woodlands at Nuuanu Honolulu |
48 | 0 | 0 | |
|
Villa Rose Waialua-haleiwa |
30 | 1 | 0 | |
|
Poamoho Wahiawa |
25 | 0 | 0 |
Non-community systems (8: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Punahou School Manoa |
4,000 | 0 | 0 | |
|
Sheraton Hotels |
2,830 | 1 | 0 | |
|
The Queen's Medical Center West Oahu Kunia |
800 | 0 | 0 | |
|
Waimano Ridge Pearlridge |
545 | 0 | 0 | |
|
Navmag Lualualei Waianae |
114 | 0 | 0 | |
|
Mililani Memorial Park Mililani Bws |
100 | 0 | 0 | |
|
Palehua Solar Observatory Makakilo |
50 | 0 | 0 | |
|
ST Stephen's Diocesan Ctr Kaneohe |
45 | 1 | 0 |
Inactive systems (31, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Hawaii records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.