Every Hawaii public water system that reported a PFAS detection during EPA UCMR 5 monitoring, how many sit above the 2024 federal limits, and the standard Hawaii applies. Concentrations are in nanograms per litre, the same unit as parts per trillion.
This is the United States view of the North American PFAS dataset. The complete dataset, including all 3,452 US systems and 97 Canadian sites, lives on the main PFAS contamination map.
Loading federal sample results
Guidance value only
Environmental Action Levels are risk screening values for soil and groundwater, not drinking water standards. The January 2026 update applies a cumulative Hazard Index approach, so PFHxS, PFNA, PFBS and HFPO-DA are assessed together rather than compared one at a time. The federal rule is what applies to public water systems. Red Hill at JBPHH remains under active response.
Compound
Limit (ng/L)
Note
PFOA
4
Water EAL, groundwater as drinking water source
PFOS
4
Water EAL, groundwater as drinking water source
PFHxS
10
Water EAL, Hazard Index input
PFNA
10
Water EAL, Hazard Index input
PFBS
2,000
Water EAL, Hazard Index input
HFPO-DA
10
Water EAL, Hazard Index input
Hawaii DOH HEER, PFAS EALs, January 2026
US EPA PFAS National Primary Drinking Water Regulation (2024)
Last reviewed 2026-08-13. Verify against the agency source before making a compliance or remediation decision.
Every count above is read straight from a published government file. Nothing is modelled, averaged, or estimated. The rules below are the exact rules used to produce the figures for Hawaii.
Who is in UCMR 5. All public water systems serving more than 3,300 people, plus a national sample of 800 smaller systems. Private wells and most small systems are not monitored, so they cannot appear here.
Which systems are listed. Only systems whose state field is HI and that reported at least one measured PFAS detection. Systems that monitored and found nothing are not shown, and their absence is not evidence of contamination.
Systems that cannot be placed. 87 systems nationally reported a detection but have no serviced ZIP code published by EPA, so they carry no location and are excluded from these counts. National totals on the map page include them.
Which value is used. The highest result a system reported for each compound across its sampling events. Results flagged by EPA as non-detects are excluded, as are the lithium results carried in the same file.
The above a limit count. A system is counted when its maximum result for a compound exceeds the 2024 federal Maximum Contaminant Level: 4 ng/L for PFOA and PFOS, 10 ng/L for PFHxS, PFNA, and HFPO-DA.
The Hazard Index count. Calculated with EPA's own mixture method for PFHxS, PFNA, HFPO-DA, and PFBS. A system is counted when the index is above 1.
What monitoring data is not. Exceeding a 2024 limit in this dataset is not a compliance violation. The federal limits carry a 2029 compliance date, which EPA proposed on 18 May 2026 to move to 2031 for PFOA and PFOS in a rule that is not final, and treatment may have been installed since the sample was taken.
If any figure on this page does not match its source file, tell Nelson and it will be corrected or removed.
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