Throughout Kailua Kona and across its water systems, EPA compliance data for HI shows above-average performance — violations are minimal, none of the tracked systems have recorded repeated MCL exceedances in recent cycles, and the safety picture has held steady across multiple reporting periods.

Data: EPA SDWIS Last verified: 2026-06-04

Overview

We track water quality and home safety data for 2 ZIP codes in Kailua Kona, Hawaii, covering 2 community water systems serving approximately 40,805 people.

No EPA violations recorded across any ZIP codes in Kailua Kona — an excellent indicator of water quality.

Home Safety Score

Average Home Safety Score for Kailua Kona: B (77/100)

The score combines three factors:

Factor	What It Measures
Water Quality	EPA violations and compliance history
Lead Levels	90th percentile lead concentration vs EPA action level
Radon Risk	EPA radon zone classification

Water Sources

Kailua Kona water systems draw from: Groundwater.

Lead & Copper

• Lead data: not yet available for Kailua Kona
• 0 ZIP codes exceed the EPA lead action level

Radon Risk

Dominant radon zone: Zone 3 (Low Risk)

• Zone 1 (High): 0 ZIP codes
• Zone 2 (Moderate): 0 ZIP codes
• Zone 3 (Low): 2 ZIP codes

Areas with No Violations

All ZIP Codes in Kailua Kona

• 96740 [B]
• 96745 [B]

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Lead/copper: EPA Lead and Copper Rule sampling data
• Radon: EPA Map of Radon Zones

Updated daily.

Cost Context: What Remediation Means for Kailua Kona Homeowners

While no remediation project is entirely without cost, the relationship between estimated remediation and property values in Kailua Kona is notably favorable — the equity share is small enough that the household financial perspective is one of proportionality rather than pressure, and most homeowners can treat it as routine planning rather than a significant financial event.

Median Home Value

$730,600

Est. Remediation

$1,500

Remediation as % of home value 0.2%

Remediation costs in Kailua Kona are relatively low compared to home values. The $1,000–$2,150 estimated range is a small fraction of median property value. Home values are 1% above the Hawaii average.

Flood & Climate Risk in Kailua Kona

Measured across the NFIP's multi-decade tracking period, Kailua Kona shows a moderate flood record — 421 claims and 100% of ZIP codes carrying FEMA flood zone status. For water quality, that combination matters because flood events at this frequency can periodically stress infrastructure: treatment plants, private wells, and distribution systems all face elevated risk during significant flooding.

421

Total FEMA Flood Claims

$23,497

Avg Claim Payout

100%

ZIPs in FEMA Flood Zones

~21

Est. Claims/Year

Kailua Kona has a moderate flood history with 421 FEMA claims averaging $23,497 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.

How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$1,500</strong> remediation cost per household.

Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.

Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.