Out of 9 ZIP codes with data in Hawaii, these are the highest-ranked areas for violations. See also: National ZIP Codes with Most EPA Water Violations | All Hawaii Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 9 |
| Highest value | 4 |
| Median value | 1 |
| State | Hawaii |
Top 9 Worst ZIP Codes
| Rank | ZIP Code | City | State | Violations | Safety Score |
|---|---|---|---|---|---|
| 1 | 96770 | Maunaloa | HI | 4 | 80/100 |
| 2 | 96744 | Kaneohe | HI | 3 | 82/100 |
| 3 | 96720 | Hilo | HI | 2 | 70/100 |
| 4 | 96721 | Hilo | HI | 2 | 86/100 |
| 5 | 96725 | Holualoa | HI | 1 | 86/100 |
| 6 | 96742 | Kalaupapa | HI | 1 | 86/100 |
| 7 | 96757 | Kualapuu | HI | 1 | 86/100 |
| 8 | 96763 | Lanai City | HI | 1 | 85/100 |
| 9 | 96857 | Schofield Barracks | HI | 1 | 86/100 |
Methodology
Violation counts include all types recorded in the EPA SDWIS database: Maximum Contaminant Level (MCL) violations, treatment technique violations, and monitoring/reporting violations. Both resolved and unresolved violations are counted. Higher counts may reflect longer system histories or larger service areas.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-06-04.
Frequently Asked Questions
What counts as an EPA water violation?
EPA violations include exceeding Maximum Contaminant Levels (MCLs), failing to treat water properly (treatment technique violations), and not testing or reporting on schedule (monitoring violations). Health-based violations are the most serious.
Does a high violation count mean the water is unsafe now?
Not necessarily. Many violations are historical or monitoring-related. However, a pattern of repeated violations indicates systemic issues with water system management or infrastructure.
Explore More Rankings
- Worst ZIP Codes for Lead in Water in Hawaii
- Lowest Home Safety Scores in Hawaii
- Safest ZIP Codes in Hawaii — Highest Safety Scores
- ZIP Codes with Highest Flood Risk in Hawaii
- ZIP Codes with Highest Energy Costs in Hawaii
- ZIP Codes with Highest Radon Risk
- ZIP Codes with PFAS Detections in Hawaii
- Least Reliable Water Systems in Hawaii
- Environmental Justice Concern Areas in Hawaii
- Worst ZIP Codes for Homebuyers in Hawaii
- ZIP Codes with Worst CO & Gas Risk in Hawaii
- Safest ZIP Codes for Gas & CO Risk in Hawaii
- ZIP Codes with Worst Wildfire Smoke Risk in Hawaii
- Safest ZIP Codes for Wildfire Smoke in Hawaii
- All Rankings