Waipahu-ewa-waianae
EPA ID: HI0000335 · 217,479 people served · 47 ZIP codes
Waipahu-ewa-waianae earns a clean bill from EPA monitoring — no violations in five years across a service area of 217,479 people.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Waipahu-ewa-waianae Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Waipahu-ewa-waianae serves a community with a median household income of $96,346 and an estimated 749,883 residents across its service area. Approximately 67% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Waipahu-ewa-waianae'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.
About 2% of homes in Honolulu County, Hawaii rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
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. 16 detections recorded.
Comparable Water Systems
Similar-sized systems in Hawaii
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
Waipahu-ewa-waianae (EPA ID: HI0000335) is a community water system in Hawaii that serves approximately 217,479 people from groundwater sources.
This system provides water to 47 ZIP codes across 7 communities.
Average Home Safety Score: C (69/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
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: 6 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 41 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
This system serves 47 ZIP codes:
96706 · 96707 · 96782 · 96786 · 96792 96797 · 96801 · 96802 · 96803 · 96804 96805 · 96806 · 96807 · 96808 · 96809 96810 · 96811 · 96812 · 96813 · 96814 96815 · 96816 · 96817 · 96818 · 96819 96820 · 96821 · 96822 · 96823 · 96824 96825 · 96826 · 96828 · 96830 · 96836 96837 · 96838 · 96839 · 96840 · 96841 96843 · 96844 · 96846 · 96847 · 96848 96849 · 96850
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Waipahu-ewa-waianae (HI0000335) on EPA.gov.
Frequently Asked Questions
Is Waipahu-ewa-waianae water safe to drink?
Based on EPA records, Waipahu-ewa-waianae has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Waipahu-ewa-waianae serve?
Waipahu-ewa-waianae serves approximately 217,479 people across 47 ZIP codes in Hawaii.
Where does Waipahu-ewa-waianae get its water?
The primary water source is groundwater.
Contact Your Water Utility
Public-record contact information for the water utility serving this system. Use these channels to request water quality reports, ask about service, or report issues directly.
Contact information from Honolulu Board of Water Supply - Waipahu-Ewa-Waianae Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility, does not act as its agent, and does not provide customer support for it. Contact details shown are public-record information from CCR filings. For service issues, contact the utility directly using the information above.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: Honolulu Board of Water Supply - Waipahu-Ewa-Waianae Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Treatment chemicals and what each one does
Chemical names are reported verbatim by the utility. Purpose categories are ZipCheckup annotations based on standard drinking-water treatment practice.
Treatment classification and chemical list sourced from Honolulu Board of Water Supply - Waipahu-Ewa-Waianae Consumer Confidence Report.
Treatment intensity is a ZipCheckup-derived classification based on the chemicals and processes the utility reports. Chemicals and contamination sources are taken verbatim from the utility's CCR filing. Routine federal monitoring and contaminant testing shown elsewhere on this page determine whether the water meets safety standards, not the treatment classification.
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 →
PFAS Substances Detected in This System
This water system's Consumer Confidence Report disclosed the following PFAS compounds. Levels are from the utility's most recent reporting cycle.
In April 2024, EPA finalized the first National Primary Drinking Water Regulation for six PFAS. Public water systems have until 2029 to comply. EPA — PFAS regulation overview →
Source: Consumer Confidence Report disclosed by Honolulu Board of Water Supply - Waipahu-Ewa-Waianae.
ZipCheckup is not affiliated with this water utility. PFAS detection data is sourced from public Consumer Confidence Reports filed by the utility itself.
Lead Service Line Replacement Tracker
This water utility's lead service line (LSL) replacement program is tracked from public Consumer Confidence Report filings. Email signup notifies subscribers when the utility files an updated replacement plan or progress milestone.
Honolulu Board of Water Supply - Waipahu-Ewa-Waianae
ZipCheckup is not affiliated with this water utility. LSL replacement-program data is sourced from public CCR filings published by the utility. Subscription notifications are based on automated parsing of subsequent CCR releases.
Learn more about Lead and Copper Rule replacement requirements →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Notable events and violations
This section summarizes events the utility chose to disclose in its most recent Consumer Confidence Report, plus any federal compliance violations the utility recorded against itself. Both lists are utility-authored — ZipCheckup does not audit, judge, or reorder them.
Notable events from the utility's CCR
These bullet entries are the utility's own narration of operational, regulatory, or infrastructure events during the reporting period.
- Biennial report (published July and December). This report is for calendar year 2024.
- One lead sample exceeded action level (Jan-Jun 2023 period) but no violation was triggered after additional testing.
- Hazard Index for PFAS: <1.0 (in compliance).
- Sources: Hoaeae Wells, Waipahu Wells I-IV, all Region 3.
ZipCheckup note: items above reflect what the utility published in its most recent CCR. Federal violation records are also tracked separately by the EPA Safe Drinking Water Information System (SDWIS) — the SDWIS record is the authoritative federal source for any specific regulatory action.
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
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Waipahu-ewa-waianae (EPA ID: HI0000335) — request the latest Consumer Confidence Report or ask about specific contaminants.