EPA UCMR 5 PFAS Monitoring Data
PFAS in Hawaii Drinking Water
Detection data from EPA UCMR 5 monitoring (2023–2025)
Last updated: May 27, 2026Monitoring results are not compliance determinations. Detection levels reflect a specific sample point and date. Utilities may have taken corrective action after sampling. Methodology
Under the EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5), public water systems are required to test for 29 PFAS compounds between 2023 and 2025. This page summarizes the monitoring results reported for 43 water utilities in Hawaii, drawn directly from EPA's published occurrence data. 0 utilities in this dataset reported samples above an EPA Maximum Contaminant Level.
Highest PFOA / PFOS detections reported
PFAS analytes — detection breakdown
Detections / total records per analyte. All 29 UCMR 5 analytes shown where records exist for Hawaii.
All HI utilities with PFAS records
43 systems| Water System | |
|---|---|
Hnl-windward-pearl Harbor Honolulu-Windward-Pearlharbor | View |
Waipahu-ewa-waianae Waipahu-Ewa-Waianae | View |
Wailuku Wailuku | View |
Joint Base Pearl Harbor-hickam Pearl Harbor | View |
Mililani Mililani Bws | View |
Hilo Hilo | View |
Schofield Barracks | View |
Lihue-kapaa Lihue-Kapaa | View |
Makawao Makawao | View |
North Kona North Kona | View |
How this data was collected
Source dataset
All records on this page are drawn from the EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) occurrence dataset, published by the U.S. Environmental Protection Agency. UCMR 5 required large public water systems (serving more than 3,300 people) to sample for 29 PFAS compounds between 2023 and 2025. EPA UCMR 5 occurrence data
Sampling methodology
Samples were collected at entry points to the distribution system (EPTDS) as required by UCMR 5 regulations. Each utility collected at least four quarterly samples during the monitoring period. Results represent concentrations at the specified sample point on the sample date — not a continuous measure of system-wide levels.
Unit normalization
Source data may express concentrations in micrograms per liter (µg/L, also written ug/L or ppb) or nanograms per liter (ng/L, also called ppt). All values on this page are normalized to ng/L (ppt) for consistent comparison with EPA Maximum Contaminant Levels (MCLs). Conversion: 1 µg/L = 1,000 ng/L. Records with unrecognized units are excluded from numeric aggregates and flagged in the raw export.
What "detection" means
A result is counted as a detection when the EPA reports it as "Detected above MRL" — meaning the analyte was measured at or above the minimum reporting limit (MRL) for that analyte. Non-detect results (below MRL) are included in total record counts but not in detection counts. Detection is a monitoring outcome, not a compliance determination.
Validation and exclusion criteria
Records are included only where validated = true and suppressed = false. Records flagged during ingestion for format errors, duplicate source hashes, or missing required fields are excluded.
Update cadence
Pages are regenerated every 24 hours via Next.js ISR. The underlying dataset is updated when EPA publishes new UCMR 5 occurrence data. The source retrieval date shown on each record reflects the date the EPA file was last downloaded to our system.
Cite this page
Water Utility Report. (2026). PFAS in Hawaii drinking water: EPA UCMR 5 monitoring records (2025). Retrieved May 27, 2026, from https://waterutilityreport.com/data/pfas/hawaii
Detection levels represent results from EPA-required compliance monitoring at the time of sampling. They are not a real-time indicator of current water quality. Utilities may have taken corrective action or installed treatment after sampling. For current information about your water, contact your utility or consult your annual Consumer Confidence Report.
At a Glance
Utilities tested
Total PFAS records
With detections
of 43
Above PFOA MCL (4 ng/L)
of 43
Above PFOS MCL (4 ng/L)
of 43
Above any individual MCL
PFOA, PFOS, PFNA, PFHxS, or HFPO-DA