- PWSID
- MN1050004
- State
- Minnesota
- System type
- community water system (CWS)
- Population served
- 13,835
- City
- Sauk Rapids
- Counties
- Benton County
- Primary source water
- groundwater
- UCMR 5 sampling
- 2023-07-17 to 2024-02-20 · 3 entry point(s) · water types: GW
- Service-area boundary
- authoritative
Hazard Index ≥ 3 × its limit highest single result
Hazard Index ≥ 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.
Water purchased from
- Sartell (MN1730036)
Seller's highest results: PFOA <MRL · PFOS <MRL · HI 0 · detected: PFBA
Seller results are the seller's own entry-point samples, not measurements of this system's water. This system's own samples (below) may reflect purchased water, its own sources, or both.
Compared with EPA's 2024 values
| Highest single result | Worst entry-point average* | Limit | |
|---|---|---|---|
| PFOA (ppt) | 8.1 | 6.55 | 4 |
| PFOS (ppt) | 12 | 9.45 | 4 |
| Hazard Index | 3.422 | 3.228 | 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) | 8.1 | 6.55 | 0.01 (guidance) |
| PFOS (ppt) | 12 | 9.45 | 2.3 (guidance) |
| PFHxS (ppt) | 34.2 | 32.25 | 47 (guidance) |
| PFBS (ppt) | 9.1 | 7.6 | 100 (guidance) |
| PFHxA (ppt) | 7.4 | 5.9 | 200 (guidance) |
| PFBA (ppt) | 14.6 | 12.4 | 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 2023-07-17 to 2024-02-20 · 3 entry point(s) · water types: GW · 6 sampling visits. PFAS in ppt (ng/L).
| Date | Entry point | Event | PFOA | PFOS | HI | Other detections |
|---|---|---|---|---|---|---|
| 2023-07-17 | Well #2 Entry Point (GW) | SE1 | 5 | 6.9 | 1.123 | PFBA 10.2, PFHxA 4.4, PFPeA 4, lithium 9.1 µg/L |
| 2023-07-17 | Well #3 Entry Point (GW) | SE1 | 5.7 | 4.4 | 3.422 | PFBA 6.1, PFHxA 5.2, PFPeA 3 |
| 2023-07-26 | TREATMENT PLANT (GW) | SE1 | <4 | <4 | 0 | none |
| 2024-02-20 | TREATMENT PLANT (GW) | SE2 | <4 | <4 | 0.002 | PFBA 5.8 |
| 2024-02-20 | Well #2 Entry Point (GW) | SE2 | 8.1 | 12 | 1.775 | PFBA 14.6, PFHpA 3.6, PFHxA 7.4, PFPeA 6 |
| 2024-02-20 | Well #3 Entry Point (GW) | SE2 | 5.3 | 4.9 | 3.033 | PFBA 8, PFHxA 4.7 |
“<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
180 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 facility 13 · sample point E04 · groundwater
| Compound | MRL | 2023-07-26 SE1 | 2024-02-20 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | < 5 | 5.8 |
| PFBS | 3 ppt | < 3 | 3.1 |
| 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 |
| PFHxA | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 |
| PFPeA | 3 ppt | < 3 | < 3 |
| 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 #2 Entry Point facility 4 · sample point E01 · groundwater
| Compound | MRL | 2023-07-17 SE1 | 2024-02-20 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 10.2 | 14.6 |
| PFBS | 3 ppt | 6.1 | 9.1 |
| PFHpA | 3 ppt | < 3 | 3.6 |
| PFHxA | 3 ppt | 4.4 | 7.4 |
| PFHxS | 3 ppt | 11.2 | 17.7 |
| PFOA | 4 ppt | 5 | 8.1 |
| PFOS | 4 ppt | 6.9 | 12 |
| PFPeA | 3 ppt | 4 | 6 |
| 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 |
| 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 | 9.1 | < 9 |
Well #3 Entry Point facility 5 · sample point E02 · groundwater
| Compound | MRL | 2023-07-17 SE1 | 2024-02-20 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 6.1 | 8 |
| PFBS | 3 ppt | 4.2 | 5.6 |
| PFHxA | 3 ppt | 5.2 | 4.7 |
| PFHxS | 3 ppt | 34.2 | 30.3 |
| PFOA | 4 ppt | 5.7 | 5.3 |
| PFOS | 4 ppt | 4.4 | 4.9 |
| PFPeA | 3 ppt | 3 | < 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 |
| 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 | 6 | 83% | 14.6 2024-02-20 | 7.45–8.28 | 6.1 | 10.2 | 14.6 | 14.6 |
| PFBS | 6 | 83% | 9.1 2024-02-20 | 4.68–5.18 | 4.2 | 6.1 | 9.1 | 9.1 |
| PFHxA | 6 | 67% | 7.4 2024-02-20 | 3.62–4.62 | 4.4 | 5.2 | 7.4 | 7.4 |
| PFHxS | 6 | 67% | 34.2 2023-07-17 | 15.57–16.57 | 11.2 | 30.3 | 34.2 | 34.2 |
| PFOA | 6 | 67% | 8.1 2024-02-20 | 4.02–5.35 | 5 | 5.7 | 8.1 | 8.1 |
| PFOS | 6 | 67% | 12 2024-02-20 | 4.7–6.03 | 4.4 | 6.9 | 12 | 12 |
| PFPeA | 6 | 50% | 6 2024-02-20 | 2.17–3.67 | <MRL | 4 | 6 | 6 |
| PFHpA | 6 | 17% | 3.6 2024-02-20 | 0.6–3.1 | <MRL | <MRL | 3.6 | 3.6 |
| lithium | 6 | 17% | 9.1 2023-07-17 | 1.52–9.02 | <MRL | <MRL | 9.1 | 9.1 |
Never detected (21): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFDA, PFDoA, PFEESA, PFHpS, PFMBA, PFMPA, PFNA, PFPeS, PFTA, PFTrDA, PFUnA.
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.