Wailuku, HI Water Safety: 85/100 (2026)
1 ZIP code · 6 water systems · Updated 2026-06-03
The water systems supplying Wailuku show a track record of above-average compliance with federal standards — consistently among the better performers in HI.
How Wailuku Compares
Data: EPA SDWIS Last verified: 2026-06-03
Wailuku Water: The Quick Version
- Average lead level: 0.0009 mg/L.
- Homes built before 1986: 46% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 11.58.
Water Systems Serving Wailuku
Federal records list 6 water systems tied to Wailuku, HI. Of those, 3 are the primary providers, meaning service conditions, rate structures, and compliance histories can differ depending on where a property sits.
Overview
We track water quality and home safety data for 1 ZIP code in Wailuku, Hawaii (population ~32,647), covering 6 community water systems serving approximately 135,932 people region-wide.
No EPA violations recorded across any ZIP codes in Wailuku — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Wailuku: A (85/100)
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
Wailuku water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0009 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 96793 | A | Wailuku | 74,511 |
All ZIP Codes in Wailuku
- 96793 [A]
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.
CDC Health Data for Wailuku
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
How Old Is Wailuku's Housing Stock?
With 46% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Roughly balanced between older and newer construction, Wailuku shows a median build year of 1981 — a mid-range figure that places meaningful amounts of the residential inventory on both sides of the 1986 federal plumbing-solder ban.
Most homes in Wailuku were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Wailuku: Remediation Cost in Perspective
Equity impact data for Wailuku lands in the favorable tier — remediation claims a small slice of what properties here are worth.
Remediation costs in Wailuku are relatively low compared to home values. The $800–$1,800 estimated range is a small fraction of median property value. Home values are 7% above the Hawaii average.
Protecting Children from Lead in Wailuku
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
46% — that captures the slice of Wailuku housing dating from before the federal ban on solder containing lead. It pairs with aggregate utility readings that either approach or cross 0.015 mg/L, the benchmark set under the EPA Lead and Copper Rule. Together, the two figures shift one-home reads into a standard household-level confirmation, particularly for families with kids. A certified lead-removal filter is available through retailer-verified channels if a kit returns results that warrant additional measures.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Wailuku
How does Wailuku's flood record connect to local water quality? The NFIP documents 102 claims — enough to signal recurring events — and 100% of ZIP codes carry FEMA flood zone status. That combination places flooding in the category of factors that can periodically affect water infrastructure, even if the area isn't among the highest-exposure communities in the NFIP dataset.
Wailuku has a moderate flood history with 102 FEMA claims averaging $11,984 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>$1,200</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.
Deep Dive Reports
Detailed analysis for Wailuku, HI