Hnl-windward-pearl Harbor
EPA ID: HI0000331 · 631,389 people served · 21 ZIP codes
ZipCheckup's reading of EPA SDWIS for Hnl-windward-pearl Harbor (HI0000331): no EPA violations recorded in the last five years. Although compliance varies widely among water utilities nationally, Hnl-windward-pearl Harbor stands out with zero EPA violations over five consecutive monitoring years, delivering safe tap water to 631,389 residents and showing no enforcement activity across the entire reporting span.
Data: EPA SDWIS
Service Area Map
Coverage area for Hnl-windward-pearl Harbor Source: EPA SDWIS service area boundaries.
Service area boundary - Grade A
Service Area Demographics
The Hnl-windward-pearl Harbor serves a community with a median household income of $104,779 and an estimated 690,827 residents across its service area. Approximately 74% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Hnl-windward-pearl Harbor's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 17 detections recorded.
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Hnl-windward-pearl Harbor (EPA ID: HI0000331) is a community water system in Hawaii that serves approximately 631,389 people from groundwater sources.
This system provides water to 21 ZIP codes across 10 communities.
ZIP-Area Home Safety Context: A (100/100)
This is the average Home Safety Score for 17 of 21 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by HI or modeled from parcel and building-footprint data.
- 96701 - Aiea
- 96734 - Kailua
- 96744 - Kaneohe
- 96782 - Pearl City
- 96795 - Waimanalo
- 96797 - Waipahu
- 96813 - Honolulu
- 96814 - Honolulu
- 96815 - Honolulu
- 96816 - Honolulu
- 96817 - Honolulu
- 96818 - Honolulu
- 96819 - Honolulu
- 96821 - Honolulu
- 96822 - Honolulu
- 96825 - Honolulu
- 96826 - Honolulu
- 96848 - Honolulu
- 96859 - Tripler Army Medical Center
- 96860 - J B P H H
- 96863 - M C B H Kaneohe Bay
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Hnl-windward-pearl Harbor (HI0000331) on EPA.gov.
Frequently Asked Questions
Is Hnl-windward-pearl Harbor water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Hnl-windward-pearl Harbor in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does Hnl-windward-pearl Harbor serve?
Hnl-windward-pearl Harbor serves approximately 631,389 people across 21 ZIP codes in Hawaii.
Where does Hnl-windward-pearl Harbor get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected below the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
How Water Systems Appear in Rankings
Water systems are evaluated by violation history, contaminant detections, and service population. Larger systems with more service connections appear in more rankings.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Hnl-windward-pearl Harbor, HI: Serves 631K People. https://zipcheckup.com/water-system/hi0000331/
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