- PWSID
- AK2320078
- State
- Alaska
- System type
- community water system (CWS)
- Population served
- 4,900
- City
- Barrow
- Counties
- North Slope Borough
- Primary source water
- surface water
- UCMR 5 sampling
- 2024-10-22 to 2024-12-03 · 3 entry point(s) · water types: SW
- Service-area boundary
- authoritative
PFOS ≥ 3 × its limit highest single result
PFOS ≥ 3 × its limit worst entry-point average
Open on the Alaska map · All Alaska systems · All results
These are monitoring results collected under EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) at entry points, where treated water enters the distribution system; they are not tap-water samples. They are not compliance determinations: compliance with EPA's 2024 PFAS limits is judged on running annual averages of compliance monitoring, required from 2029, so a single UCMR 5 result at or above a limit is not a violation. “< MRL” means the compound was not quantified at EPA's minimum reporting level; it does not mean zero.
Compared with EPA's 2024 values
| Highest single result | Worst entry-point average* | Limit | |
|---|---|---|---|
| PFOA (ppt) | <MRL | 0 | 4 |
| PFOS (ppt) | 46.3 | 44.05 | 4 |
| Hazard Index | 1.85 | 1.732 | 1.0† |
“<MRL” = every result for the compound was below its reporting limit. * Mean of all samples at each entry point with non-detects = 0 (EPA compliance convention; the Hazard Index also uses non-detects = 0); a screening comparison, not a formal running annual average. † Rescission proposed May 2026. PFOA/PFOS MCL 4 ppt (2024 NPDWR, in effect). PFHxS, PFNA, HFPO-DA (10 ppt each) and the Hazard Index (1.0) are 2024 NPDWR values; EPA proposed rescinding them on 18 May 2026 (comment period closed 20 Jul 2026).
No Alaska PFAS drinking-water standard in effect or proposed as of 2026-10-17: No Alaska-specific PFAS standard for public water systems; DEC Drinking Water Program implements the federal NPDWR (DEC PFAS page, revised 2025-10-29).
Sampling history
Sampled 2024-10-22 to 2024-12-03 · 3 entry point(s) · water types: SW · 12 sampling visits. PFAS in ppt (ng/L).
| Date | Entry point | Event | PFOA | PFOS | HI | Other detections |
|---|---|---|---|---|---|---|
| 2024-10-22 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE1 | <4 | <4 | 0 | none |
| 2024-10-22 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE1 | <4 | <4 | 0 | none |
| 2024-10-22 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE1 | <4 | 40.7 | 1.61 | PFBA 11, PFHpA 3.3, PFHxA 7.3, PFPeA 4.9 |
| 2024-11-18 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE2 | <4 | <4 | 0 | none |
| 2024-11-18 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE2 | <4 | <4 | 0 | none |
| 2024-11-18 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE2 | <4 | 44.5 | 1.85 | PFBA 11.5, PFHpA 3.8, PFHxA 5.9 |
| 2024-11-26 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE4 | <4 | <4 | 0 | none |
| 2024-11-26 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE4 | <4 | <4 | 0 | none |
| 2024-11-26 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE4 | <4 | 44.7 | 1.76 | PFBA 10, PFHpA 3.9, PFHxA 6.5, PFPeA 6 |
| 2024-12-03 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE3 | <4 | <4 | 0 | none |
| 2024-12-03 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE3 | <4 | <4 | 0 | none |
| 2024-12-03 | BARROW UTILITIES & ELEC. COOP., INC. (BU (SW) | SE3 | <4 | 46.3 | 1.71 | PFBA 9.7, PFHpA 3.9, PFHxA 8.1, PFPeA 3.9 |
“<4” = not detected at the reporting limit shown; “n/a” = not analyzed in that sample. Highlighted = at or above the 4 ppt MCL. HI computed per sample with non-detects as 0. Other detections lists every other quantified compound (lithium in µg/L).
All results by entry point
360 results. Each column is one sampling visit (date and UCMR 5 sample event). A number is a measured concentration; “< 4” = below the minimum reporting level shown; “–” = not analyzed in that visit. PFAS in ppt (ng/L); lithium in µg/L.
BARROW UTILITIES & ELEC. COOP., INC. (BU facility SF001 · sample point SPSF001 · surface water
| Compound | MRL | 2024-10-22 SE1 | 2024-11-18 SE2 | 2024-11-26 SE4 | 2024-12-03 SE3 |
|---|---|---|---|---|---|
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 | < 6 | < 6 |
| PFBA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| PFBS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHxA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFPeA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFPeS | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 | < 9 | < 9 |
BARROW UTILITIES & ELEC. COOP., INC. (BU facility SF002 · sample point SPSF002 · surface water
| Compound | MRL | 2024-10-22 SE1 | 2024-11-18 SE2 | 2024-11-26 SE4 | 2024-12-03 SE3 |
|---|---|---|---|---|---|
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 | < 6 | < 6 |
| PFBA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| PFBS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHxA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFPeA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFPeS | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 | < 9 | < 9 |
BARROW UTILITIES & ELEC. COOP., INC. (BU facility TP001 · sample point SPTP001 · surface water
| Compound | MRL | 2024-10-22 SE1 | 2024-11-18 SE2 | 2024-11-26 SE4 | 2024-12-03 SE3 |
|---|---|---|---|---|---|
| PFBA | 5 ppt | 11 | 11.5 | 10 | 9.7 |
| PFHpA | 3 ppt | 3.3 | 3.8 | 3.9 | 3.9 |
| PFHxA | 3 ppt | 7.3 | 5.9 | 6.5 | 8.1 |
| PFHxS | 3 ppt | 16.1 | 18.5 | 17.6 | 17.1 |
| PFOS | 4 ppt | 40.7 | 44.5 | 44.7 | 46.3 |
| PFPeA | 3 ppt | 4.9 | < 3 | 6 | 3.9 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 | < 9 | < 9 |
Statistics by compound
| Compound | Results | Detected | Highest (date) | Mean bounds | KM median | P75 | P90 | P95 |
|---|---|---|---|---|---|---|---|---|
| PFBA | 12 | 33% | 11.5 2024-11-18 | 3.52–6.85 | <MRL | 9.7 | 11 | 11.5 |
| PFHpA | 12 | 33% | 3.9 2024-11-26 | 1.24–3.24 | <MRL | 3.3 | 3.9 | 3.9 |
| PFHxA | 12 | 33% | 8.1 2024-12-03 | 2.32–4.32 | <MRL | 5.9 | 7.3 | 8.1 |
| PFHxS | 12 | 33% | 18.5 2024-11-18 | 5.78–7.78 | <MRL | 16.1 | 17.6 | 18.5 |
| PFOS | 12 | 33% | 46.3 2024-12-03 | 14.68–17.35 | <MRL | 40.7 | 44.7 | 46.3 |
| PFPeA | 12 | 25% | 6 2024-11-26 | 1.23–3.48 | <MRL | <MRL | 4.9 | 6 |
Never detected (24): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFBS, PFDA, PFDoA, PFEESA, PFHpS, PFMBA, PFMPA, PFNA, PFOA, PFPeS, PFTA, PFTrDA, PFUnA, lithium.
Left-censored Kaplan–Meier statistics (Helsel 2005; Helsel & Lee 2006, NADA for R). Units: ppt; lithium µg/L. Each compound has one reporting limit, so the Kaplan–Meier mean equals the upper mean bound (non-detects at the MRL); the lower bound sets non-detects to 0. “<MRL” = the percentile falls below the reporting limit and cannot be estimated. These describe this system's UCMR 5 samples, not population estimates.
Sources
- EPA UCMR 5 occurrence data text files (UCMR5_All.txt; samples 2023-01-08 to 2026-03-02; data summary dated Jul 2026)
- EPA SDWIS via ECHO SDWA downloads, quarter 2026Q3
- EPA Public Water System Service Areas v3 (Mar 2026)
- US Census Bureau cartographic boundary counties 1:500k, 2024
- U.S. Geological Survey, 2014, 1:1,000,000-Scale Streams of the United States (streaml010g), National Map Small-Scale Collection; Strahler order 2+ on the 1:1M network (NHDPlus V2 does not cover Alaska). Coarser than the NHDPlus layer used for other states; mapped streams do not extend west of about 170.7 W (western Aleutians)
Data build f5ae0997fdb0 · 2026-10-18T04:03Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.