Honolulu County, Hawaii
66 ZIP codes · Avg score 80/100 · Grade B · Updated 2026-06-03
Recent water monitoring in Honolulu County shows 66 ZIP codes with consistently safe results.
How Honolulu County Compares
How Honolulu County Compares
Honolulu County scores 1 points above the Hawaii state average (79/100) and 12 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Honolulu County, Hawaii
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 10.6 (asthma 9.5%, diabetes 12.4%)
Estimated additional annual cost per homeowner: $1,262, driven primarily by flood
Infrastructure: 0.299% avg pipe failure probability, 17% of ZIPs at high risk
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,262
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Honolulu County
Remediation costs are relatively manageable for most homeowners in Honolulu County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Honolulu County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Honolulu County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | HNL-WINDWARD-PEARL HARBOR | 631,389 | 3 |
| 2 | MARINE CORPS BASE HAWAII | 16,300 | 3 |
| 3 | SCHOFIELD BARRACKS | 37,920 | 1 |
| 4 | Fort Shafter | 7,067 | 1 |
| 5 | Tripler Army Medical Cntr | 5,555 | 1 |
28 total water systems serve Honolulu County.
All ZIP Codes in Honolulu County
66 ZIP codes tracked in Honolulu County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 96768 | Makawao | 95 | A | 0 | $905K |
| 2 | 96759 | Kunia | 88 | A | 0 | — |
| 3 | 96802 | Honolulu | 88 | A | 0 | — |
| 4 | 96805 | Honolulu | 88 | A | 0 | — |
| 5 | 96806 | Honolulu | 88 | A | 0 | — |
| 6 | 96807 | Honolulu | 88 | A | 0 | — |
| 7 | 96808 | Honolulu | 88 | A | 0 | — |
| 8 | 96809 | Honolulu | 88 | A | 0 | — |
| 9 | 96812 | Honolulu | 88 | A | 0 | — |
| 10 | 96823 | Honolulu | 88 | A | 0 | — |
| 11 | 96824 | Honolulu | 88 | A | 0 | — |
| 12 | 96828 | Honolulu | 88 | A | 0 | — |
| 13 | 96836 | Honolulu | 88 | A | 0 | — |
| 14 | 96837 | Honolulu | 88 | A | 0 | — |
| 15 | 96838 | Honolulu | 88 | A | 0 | — |
| 16 | 96839 | Honolulu | 88 | A | 0 | — |
| 17 | 96840 | Honolulu | 88 | A | 0 | — |
| 18 | 96841 | Honolulu | 88 | A | 0 | — |
| 19 | 96843 | Honolulu | 88 | A | 0 | — |
| 20 | 96844 | Honolulu | 88 | A | 0 | — |
| 21 | 96846 | Honolulu | 88 | A | 0 | — |
| 22 | 96847 | Honolulu | 88 | A | 0 | — |
| 23 | 96848 | Honolulu | 88 | A | 0 | — |
| 24 | 96849 | Honolulu | 88 | A | 0 | — |
| 25 | 96850 | Honolulu | 88 | A | 0 | — |
| 26 | 96731 | Kahuku | 87 | A | 0 | $813K |
| 27 | 96786 | Wahiawa | 87 | A | 0 | $724K |
| 28 | 96797 | Waipahu | 87 | A | 0 | $799K |
| 29 | 96801 | Honolulu | 87 | A | 0 | — |
| 30 | 96803 | Honolulu | 87 | A | 0 | — |
| 31 | 96804 | Honolulu | 87 | A | 0 | — |
| 32 | 96810 | Honolulu | 87 | A | 0 | — |
| 33 | 96811 | Honolulu | 87 | A | 0 | — |
| 34 | 96814 | Honolulu | 87 | A | 0 | $707K |
| 35 | 96818 | Honolulu | 87 | A | 0 | $653K |
| 36 | 96820 | Honolulu | 87 | A | 0 | — |
| 37 | 96830 | Honolulu | 87 | A | 0 | — |
| 38 | 96857 | Schofield Barracks | 86 | A | 1 | — |
| 39 | 96701 | Aiea | 82 | B | 0 | $913K |
| 40 | 96744 | Kaneohe | 82 | B | 3 | $1001K |
| 41 | 96782 | Pearl City | 82 | B | 0 | $846K |
| 42 | 96813 | Honolulu | 82 | B | 0 | $804K |
| 43 | 96817 | Honolulu | 82 | B | 0 | $930K |
| 44 | 96762 | Laie | 77 | B | 0 | $962K |
| 45 | 96815 | Honolulu | 77 | B | 0 | $628K |
| 46 | 96816 | Honolulu | 77 | B | 0 | $1121K |
| 47 | 96819 | Honolulu | 77 | B | 0 | $964K |
| 48 | 96822 | Honolulu | 77 | B | 0 | $985K |
| 49 | 96825 | Honolulu | 77 | B | 0 | $1068K |
| 50 | 96826 | Honolulu | 77 | B | 0 | $485K |
| 51 | 96707 | Kapolei | 73 | B | 0 | $772K |
| 52 | 96789 | Mililani | 73 | B | 0 | $871K |
| 53 | 96821 | Honolulu | 72 | B | 0 | $1458K |
| 54 | 96709 | Kapolei | 66 | C | 0 | — |
| 55 | 96853 | J B P H H | 66 | C | 0 | — |
| 56 | 96854 | Wheeler Army Airfield | 66 | C | 0 | — |
| 57 | 96859 | Tripler Army Medical Center | 66 | C | 0 | — |
| 58 | 96861 | Camp H M Smith | 66 | C | 0 | — |
| 59 | 96863 | M C B H Kaneohe Bay | 66 | C | 0 | — |
| 60 | 96706 | Ewa Beach | 60 | C | 0 | $797K |
| 61 | 96717 | Hauula | 60 | C | 0 | $874K |
| 62 | 96730 | Kaaawa | 60 | C | 0 | $982K |
| 63 | 96791 | Waialua | 60 | C | 0 | $932K |
| 64 | 96712 | Haleiwa | 55 | C | 0 | $1264K |
| 65 | 96734 | Kailua | 55 | C | 0 | $1246K |
| 66 | 96792 | Waianae | 55 | C | 0 | $551K |
Recommended Buyer Guides for Honolulu County
Retailer arrangements don't shape what appears here — the selection logic is independent, filtered against EPA detections and the federal hazard data on file for this county.
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Honolulu County, Hawaii
Overview
Honolulu County in Hawaii covers 66 ZIP codes with an average Home Safety Score of B (80/100).
2 of 66 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← Back to Hawaii water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.