Hawaii Water Quality Report 2026
Hawaii tap water is safe to drink based on our analysis of 4 water systems serving 484,879 residents. The average PurityMap score is 85.0/100 (Grade: A), which is 7.1 points above the national average.
- No major contaminant flags across Hawaii cities. All cities meet EPA federal drinking water standards.
Hawaii water is generally good quality. A carbon pitcher or faucet filter removes chlorine taste and provides extra protection. No major filtration investment is needed for most residents.
Soft
Hawaii is 7.1 points above the US average of 77.9/100. Hardness is 3.5 GPG below the US average of 6.3 GPG.
All 4 cities score similarly
How Hawaii's 4 cities score on the PurityMap 0–100 scale:
Water quality for the most populated cities. Click any city for details.
| City | Population | Score | Hardness | Key Issues |
|---|---|---|---|---|
| Honolulu | 351K | 85/100 | 3.5 GPG | — |
| Pearl City | 48K | 85/100 | 3.2 GPG | — |
| Hilo | 46K | 85/100 | 1.8 GPG | — |
| Kailua | 41K | 85/100 | 2.8 GPG | — |
Hawaii generally has soft to moderate water. Average: 2.8 GPG (Soft). Most residents do not need a softener.
Based on EPA UCMR5 data, PFAS have not been detected above advisory levels in any Hawaii cities in our database as of 2026.
All Hawaii cities have lead below 5 ppb. Average: 1.2 ppb. Individual homes with older plumbing may have higher levels.
Where Hawaii gets its drinking water, based on 4 water systems.
| Source Type | Cities | % of Total |
|---|---|---|
| Mixed (Ground + Surface) | 2 | 50% |
| Groundwater | 2 | 50% |
Hawaii water is generally good. A carbon pitcher filter improves taste.
| # | City | Pop. | Score | Hardness | Lead | PFAS | TDS |
|---|---|---|---|---|---|---|---|
| 1 | Honolulu | 351K | 85/100 | 3.5 GPG (Soft) | 1.5 ppb | ✅ No | 150 ppm |
| 2 | Pearl City | 48K | 85/100 | 3.2 GPG (Soft) | 1.2 ppb | ✅ No | 140 ppm |
| 3 | Hilo | 46K | 85/100 | 1.8 GPG (Soft) | 1.0 ppb | ✅ No | 55 ppm |
| 4 | Kailua | 41K | 85/100 | 2.8 GPG (Soft) | 1.2 ppb | ✅ No | 125 ppm |
Hawaii has 2 utilities. Major: Honolulu Board of Water Supply, County of Hawaii Department of Water Supply.
Sources: Groundwater and surface water, Groundwater, Surface water and groundwater.
- EPA Safe Drinking Water Information System
- EWG Tap Water Database
- State utility Consumer Confidence Reports
- USGS regional water monitoring data
PurityMap compiles publicly available data and does not perform independent testing.
4 city water quality reports available for Hawaii.
Honolulu Water Quality Report
Kailua Water Quality Report
Pearl City Water Quality Report
Compare water quality reports across all 50 US states