Hawaii: drinking water & radon
Hawaii has 118 active community water systems. Since 2016, 7 reported health-based violations; 0 had a latest lead result above 15 ppb; 0 measured PFOA or PFOS at or above 4 ppt.
Radon zones in Hawaii
tap a countyMost health-based violations
| Waiawa Correctional Facility 444 people | 5 |
| Waiahole 300 people | 1 |
| Keopu Water Association 250 people | 1 |
| Villa Rose 30 people | 1 |
| Shasta Cascade Mobilehome Park 100 people | 1 |
| Maunaloa-Kaluakoi 1,000 people | 1 |
| Makawao 29,868 people | 1 |
Highest latest lead (90th percentile)
| Lower Kula 3,522 people | 3.7 ppb |
| Shasta Cascade Mobilehome Park 100 people | 0.9 ppb |
| Kawela Plantation 553 people | 0 ppb |
| Baldwin Ranch Estates 32 people | 0 ppb |
| Moloaa Irrigation Cooperative 100 people | 0 ppb |
| Kona Water Service Company 260 people | 0 ppb |
| Pepeekeo Water Association 60 people | 0 ppb |
| Wood Valley 75 people | 0 ppb |
| Maui Highlands 26 people | 0 ppb |
| Barbers Point 5,256 people | 0 ppb |
Largest systems
| HNL-Windward-Pearl Harbor 631,389 people | 631,389 |
| Waipahu-Ewa-Waianae 217,479 people | 217,479 |
| Wailuku 74,511 people | 74,511 |
| Joint Base Pearl Harbor-Hickam 65,230 people | 65,230 |
| Mililani 50,573 people | 50,573 |
| Hilo 39,477 people | 39,477 |
| Schofield Barracks 37,920 people | 37,920 |
| Lihue-Kapaa 34,854 people | 34,854 |
| Makawao 29,868 people | 29,868 |
| North Kona 29,581 people | 29,581 |
All ZIP codes in Hawaii
131 ZIP codes.
What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.
Questions
How many water systems in Hawaii have violations?
7 of 118 active community water systems in Hawaii reported at least one health-based violation since 2016 (EPA SDWIS).
What is the radon risk in Hawaii?
No ZIP codes are in EPA radon zone 1, 0 in zone 2 and 131 in zone 3. EPA recommends testing every home.