All 41 systems had enough required samples to calculate a yearly average. 0 had at least one yearly average at or above a study benchmark; 41 did not.
EPA-based study benchmark: the unrounded cutoff this research uses to reproduce EPA’s January 2026 technical-assistance classification around the April 2024 federal levels. It is not a current standard or compliance finding and cannot determine household exposure or health risk.
Find your water system
ZIP codes are used only to route visitors to public water systems that reported serving them. Confirm the actual provider using a water bill or utility record.
System counts in Hawaii
Each count shows how many included water systems had a yearly average at or above the named study benchmark.
| Study benchmark | Systems at or above benchmark | Water systems included | Percent |
|---|---|---|---|
| PFOA: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt) | 0 | 41 | 0.0% |
| PFOS: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt) | 0 | 41 | 0.0% |
| PFHxS: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 41 | 0.0% |
| PFNA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 41 | 0.0% |
| HFPO-DA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 41 | 0.0% |
| Hazard Index: 1.5 study benchmark with at least two detected components (reproduces EPA classification around 1) | 0 | 41 | 0.0% |
Community water systems with complete monitoring
“Complete monitoring” means at least one sampling location had all required samples needed for a yearly average. Each PWSID appears once, preventing double counting across ZIP associations.
| Public water system | PWSID | Population served | Primary source | Sampling locations | Study benchmark result |
|---|---|---|---|---|---|
| ALIAMANU | HI0000337 | 6,406 | Ground water purchased | 1 | Below all study benchmarks |
| BARBERS POINT | HI0000355 | 5,256 | Ground water | 1 | Below all study benchmarks |
| FORT SHAFTER | HI0000341 | 7,067 | Ground water | 1 | Below all study benchmarks |
| HANAPEPE-ELEELE | HI0000404 | 5,592 | Ground water | 3 | Below all study benchmarks |
| HAWAII VOLCANOES NAT.PARK | HI0000146 | 4,201 | Ground water | 1 | Below all study benchmarks |
| HAWAIIAN BEACHES | HI0000117 | 3,546 | Ground water | 1 | Below all study benchmarks |
| HILO | HI0000101 | 39,477 | Ground water | 5 | Below all study benchmarks |
| HNL-WINDWARD-PEARL HARBOR | HI0000331 | 631,389 | Ground water | 45 | Below all study benchmarks |
| JOINT BASE PEARL HARBOR-HICKAM | HI0000360 | 65,230 | Ground water | 1 | Below all study benchmarks |
| KAANAPALI | HI0000205 | 8,000 | Ground water | 2 | Below all study benchmarks |
| KALAHEO-KOLOA | HI0000434 | 12,660 | Ground water | 9 | Below all study benchmarks |
| KAMEHAMEHA SCHOOLS | HI0000319 | 4,000 | Ground water | 2 | Below all study benchmarks |
| KAPALUA | HI0000204 | 4,200 | Ground water | 1 | Below all study benchmarks |
| KAUNAKAKAI | HI0000234 | 3,702 | Ground water | 1 | Below all study benchmarks |
| KEANAE | HI0000219 | 270 | Ground water | 1 | Below all study benchmarks |
| KEKAHA-WAIMEA | HI0000406 | 5,998 | Ground water | 6 | Below all study benchmarks |
| KILAUEA | HI0000407 | 3,420 | Ground water | 1 | Below all study benchmarks |
| LAHAINA | HI0000214 | 20,065 | Surface water | 5 | Below all study benchmarks |
| LIHUE-KAPAA | HI0000400 | 34,854 | Surface water | 17 | Below all study benchmarks |
| LOWER KULA | HI0000247 | 3,522 | Surface water | 1 | Below all study benchmarks |
| MAKAWAO | HI0000213 | 29,868 | Surface water | 4 | Below all study benchmarks |
| MARINE CORPS BASE HAWAII | HI0000356 | 16,300 | Ground water purchased | 1 | Below all study benchmarks |
| MILILANI | HI0000367 | 50,573 | Ground water | 3 | Below all study benchmarks |
| NCTAMS EASTPAC | HI0000357 | 6,470 | Ground water | 1 | Below all study benchmarks |
| NORTH KOHALA | HI0000129 | 4,933 | Ground water | 2 | Below all study benchmarks |
| NORTH KONA | HI0000131 | 29,581 | Ground water | 11 | Below all study benchmarks |
| OLAA-MOUNTAIN VIEW | HI0000112 | 6,467 | Ground water | 2 | Below all study benchmarks |
| PRINCEVILLE | HI0000428 | 6,911 | Ground water | 2 | Below all study benchmarks |
| SCHOFIELD BARRACKS | HI0000345 | 37,920 | Ground water | 1 | Below all study benchmarks |
| SOUTH KOHALA | HI0000130 | 9,612 | Surface water | 1 | Below all study benchmarks |
| SOUTH KONA | HI0000132 | 6,512 | Ground water | 4 | Below all study benchmarks |
| THE QUEEN'S MEDICAL CENTER | HI0000312 | 3,440 | Ground water | 1 | Below all study benchmarks |
| TRIPLER ARMY MEDICAL CNTR | HI0000346 | 5,555 | Ground water | 1 | Below all study benchmarks |
| UPPER KULA | HI0000215 | 7,686 | Surface water | 1 | Below all study benchmarks |
| WAHIAWA | HI0000333 | 23,348 | Ground water | 2 | Below all study benchmarks |
| WAIALEE-SUNSET BEACH | HI0000366 | 4,916 | Ground water | 3 | Below all study benchmarks |
| WAIALUA | HI0000332 | 9,996 | Ground water | 1 | Below all study benchmarks |
| WAIKOLOA | HI0000135 | 12,100 | Ground water | 2 | Below all study benchmarks |
| WAILUKU | HI0000212 | 74,511 | Surface water | 11 | Below all study benchmarks |
| WAIPAHU-EWA-WAIANAE | HI0000335 | 217,479 | Ground water | 17 | Below all study benchmarks |
| WAIPIO HEIGHTS | HI0000334 | 11,516 | Ground water | 2 | Below all study benchmarks |
What is included
Each active community water system with enough required samples for a yearly average is counted once, even if it is linked with several ZIP codes. This does not mean every home was tested. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system. This page does not apply Hawaii's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.