- PWSID
- MN1190012
- State
- Minnesota
- System type
- community water system (CWS)
- Population served
- 23,222
- City
- Hastings
- Counties
- Dakota County
- Primary source water
- groundwater
- UCMR 5 sampling
- 2024-11-06 to 2025-10-22 · 5 entry point(s) · water types: GW
- Service-area boundary
- authoritative
PFOA ≥ 3 × its limit highest single result
PFOA ≥ 3 × its limit worst entry-point average
Open on the Minnesota map · All Minnesota 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) | 23.7 | 21.05 | 4 |
| PFOS (ppt) | 4.6 | 4.55 | 4 |
| Hazard Index | 0.342 | 0.171 | 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).
Compared with Minnesota guidance levels
| Highest single result | Worst entry-point average* | Minnesota | |
|---|---|---|---|
| PFOA (ppt) | 23.7 | 21.05 | 0.01 (guidance) |
| PFOS (ppt) | 4.6 | 4.55 | 2.3 (guidance) |
| PFHxS (ppt) | 3.4 | 1.7 | 47 (guidance) |
| PFBS (ppt) | 3.3 | 1.65 | 100 (guidance) |
| PFHxA (ppt) | 9.2 | 7.6 | 200 (guidance) |
| PFBA (ppt) | 380 | 239.15 | 7,000 (guidance) |
Sum standards add the listed compounds within each sample (non-detects = 0). State compliance is normally judged on averages over time; these are screening comparisons.
Sampling history
Sampled 2024-11-06 to 2025-10-22 · 5 entry point(s) · water types: GW · 12 sampling visits. PFAS in ppt (ng/L).
| Date | Entry point | Event | PFOA | PFOS | HI | Other detections |
|---|---|---|---|---|---|---|
| 2024-11-06 | TREATMENT PLANT #1 (GW) | SE1 | 18.5 | <4 | 0.342 | PFBA 98.3, PFHxA 9.2, PFPeA 20.5 |
| 2024-11-06 | Well #4 Entry Point (GW) | SE1 | 5.3 | <4 | 0 | PFBA 53.3, PFHxA 4.2, PFPeA 10.1 |
| 2024-11-06 | Well #6 Entry Point (GW) | SE1 | 7.2 | <4 | 0 | PFHxA 3.8, PFPeA 9 |
| 2024-11-06 | Well #7 Entry Point (GW) | SE1 | 9.5 | 4.6 | 0.31 | PFBA 64.6, PFHxA 5.4, PFPeA 8.8 |
| 2024-11-06 | Well #8 Entry Point (GW) | SE1 | 23.7 | <4 | 0 | PFBA 74.2, PFHxA 4.8, PFPeA 9.4 |
| 2025-06-11 | TREATMENT PLANT #1 (GW) | SE2 | 10.4 | <4 | 0 | PFHxA 6, PFPeA 14.3 |
| 2025-06-11 | Well #4 Entry Point (GW) | SE2 | <4 | <4 | 0 | PFBA 240, PFHxA 3, PFPeA 9.5 |
| 2025-06-11 | Well #6 Entry Point (GW) | SE2 | 5.9 | <4 | 0 | PFBA 159, PFPeA 8.2 |
| 2025-06-11 | Well #7 Entry Point (GW) | SE2 | 7.4 | 4.5 | 0 | PFBA 154, PFHxA 4.1, PFPeA 9 |
| 2025-06-11 | Well #8 Entry Point (GW) | SE2 | 18.4 | <4 | 0 | PFBA 151, PFHxA 3.8, PFPeA 8.9 |
| 2025-10-22 | TREATMENT PLANT #1 (GW) | SE2 | n/a | n/a | n/a | PFBA 380 |
| 2025-10-22 | Well #6 Entry Point (GW) | SE1 | n/a | n/a | n/a | PFBA 185 |
“<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
300 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.
TREATMENT PLANT #1 facility 25 · sample point E08 · groundwater
| Compound | MRL | 2024-11-06 SE1 | 2025-06-11 SE2 | 2025-10-22 SE2 |
|---|---|---|---|---|
| PFBA | 5 ppt | 98.3 | – | 380 |
| PFBS | 3 ppt | 3.3 | < 3 | – |
| PFHxA | 3 ppt | 9.2 | 6 | – |
| PFHxS | 3 ppt | 3.4 | < 3 | – |
| PFOA | 4 ppt | 18.5 | 10.4 | – |
| PFPeA | 3 ppt | 20.5 | 14.3 | – |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 | – |
| 4:2 FTS | 3 ppt | < 3 | < 3 | – |
| 6:2 FTS | 5 ppt | < 5 | < 5 | – |
| 8:2 FTS | 5 ppt | < 5 | < 5 | – |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 | – |
| ADONA | 3 ppt | < 3 | < 3 | – |
| HFPO-DA | 5 ppt | < 5 | < 5 | – |
| NEtFOSAA | 5 ppt | < 5 | < 5 | – |
| NFDHA | 20 ppt | < 20 | < 20 | – |
| NMeFOSAA | 6 ppt | < 6 | < 6 | – |
| PFDA | 3 ppt | < 3 | < 3 | – |
| PFDoA | 3 ppt | < 3 | < 3 | – |
| PFEESA | 3 ppt | < 3 | < 3 | – |
| PFHpA | 3 ppt | < 3 | < 3 | – |
| PFHpS | 3 ppt | < 3 | < 3 | – |
| PFMBA | 3 ppt | < 3 | < 3 | – |
| PFMPA | 4 ppt | < 4 | < 4 | – |
| PFNA | 4 ppt | < 4 | < 4 | – |
| PFOS | 4 ppt | < 4 | < 4 | – |
| PFPeS | 4 ppt | < 4 | < 4 | – |
| PFTA | 8 ppt | < 8 | < 8 | – |
| PFTrDA | 7 ppt | < 7 | < 7 | – |
| PFUnA | 2 ppt | < 2 | < 2 | – |
| lithium | 9 µg/L | < 9 | < 9 | – |
Well #4 Entry Point facility 9 · sample point E03 · groundwater
| Compound | MRL | 2024-11-06 SE1 | 2025-06-11 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 53.3 | 240 |
| PFHxA | 3 ppt | 4.2 | 3 |
| PFOA | 4 ppt | 5.3 | < 4 |
| PFPeA | 3 ppt | 10.1 | 9.5 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Well #6 Entry Point facility 11 · sample point E05 · groundwater
| Compound | MRL | 2024-11-06 SE1 | 2025-06-11 SE2 | 2025-10-22 SE1 |
|---|---|---|---|---|
| PFBA | 5 ppt | – | 159 | 185 |
| PFHxA | 3 ppt | 3.8 | < 3 | – |
| PFOA | 4 ppt | 7.2 | 5.9 | – |
| PFPeA | 3 ppt | 9 | 8.2 | – |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 | – |
| 4:2 FTS | 3 ppt | < 3 | < 3 | – |
| 6:2 FTS | 5 ppt | < 5 | < 5 | – |
| 8:2 FTS | 5 ppt | < 5 | < 5 | – |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 | – |
| ADONA | 3 ppt | < 3 | < 3 | – |
| HFPO-DA | 5 ppt | < 5 | < 5 | – |
| NEtFOSAA | 5 ppt | < 5 | < 5 | – |
| NFDHA | 20 ppt | < 20 | < 20 | – |
| NMeFOSAA | 6 ppt | < 6 | < 6 | – |
| PFBS | 3 ppt | < 3 | < 3 | – |
| PFDA | 3 ppt | < 3 | < 3 | – |
| PFDoA | 3 ppt | < 3 | < 3 | – |
| PFEESA | 3 ppt | < 3 | < 3 | – |
| PFHpA | 3 ppt | < 3 | < 3 | – |
| PFHpS | 3 ppt | < 3 | < 3 | – |
| PFHxS | 3 ppt | < 3 | < 3 | – |
| PFMBA | 3 ppt | < 3 | < 3 | – |
| PFMPA | 4 ppt | < 4 | < 4 | – |
| PFNA | 4 ppt | < 4 | < 4 | – |
| PFOS | 4 ppt | < 4 | < 4 | – |
| PFPeS | 4 ppt | < 4 | < 4 | – |
| PFTA | 8 ppt | < 8 | < 8 | – |
| PFTrDA | 7 ppt | < 7 | < 7 | – |
| PFUnA | 2 ppt | < 2 | < 2 | – |
| lithium | 9 µg/L | < 9 | < 9 | – |
Well #7 Entry Point facility 12 · sample point E06 · groundwater
| Compound | MRL | 2024-11-06 SE1 | 2025-06-11 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 64.6 | 154 |
| PFHxA | 3 ppt | 5.4 | 4.1 |
| PFHxS | 3 ppt | 3.1 | < 3 |
| PFOA | 4 ppt | 9.5 | 7.4 |
| PFOS | 4 ppt | 4.6 | 4.5 |
| PFPeA | 3 ppt | 8.8 | 9 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Well #8 Entry Point facility 23 · sample point E07 · groundwater
| Compound | MRL | 2024-11-06 SE1 | 2025-06-11 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 74.2 | 151 |
| PFHxA | 3 ppt | 4.8 | 3.8 |
| PFOA | 4 ppt | 23.7 | 18.4 |
| PFPeA | 3 ppt | 9.4 | 8.9 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Statistics by compound
| Compound | Results | Detected | Highest (date) | Mean bounds | KM median | P75 | P90 | P95 |
|---|---|---|---|---|---|---|---|---|
| PFBA | 10 | 100% | 380 2025-10-22 | 155.94–155.94 | 151 | 185 | 240 | 380 |
| PFPeA | 10 | 100% | 20.5 2024-11-06 | 10.77–10.77 | 9 | 10.1 | 14.3 | 20.5 |
| PFHxA | 10 | 90% | 9.2 2024-11-06 | 4.43–4.73 | 4.1 | 5.4 | 6 | 9.2 |
| PFOA | 10 | 90% | 23.7 2024-11-06 | 10.63–11.03 | 7.4 | 18.4 | 18.5 | 23.7 |
| PFHxS | 10 | 20% | 3.4 2024-11-06 | 0.65–3.05 | <MRL | <MRL | 3.1 | 3.4 |
| PFOS | 10 | 20% | 4.6 2024-11-06 | 0.91–4.11 | <MRL | <MRL | 4.5 | 4.6 |
| PFBS | 10 | 10% | 3.3 2024-11-06 | 0.33–3.03 | <MRL | <MRL | <MRL | 3.3 |
Never detected (23): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFMBA, PFMPA, PFNA, 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 2023-01-04 to 2026-02-23; 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
- EPA/USGS NHDPlus V2 (medium resolution) flowlines, Strahler order 2+
Data build b4430eb8fd55 · 2026-10-18T04:07Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.