Also detected, no federal limit: PFBA, PFPeA.
Is there PFAS in Cottage Grove water?
Yes, at low levels. 2 PFAS were detected, all below EPA's 2024 limits.
Cottage Grove is a public water system drawing on groundwater, based in Cottage Grove, Minnesota, serving about 42,760 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 10 times across 5 sampling points between Oct 2024 and Apr 2025.
Every PFAS detected
| PFAS | Detected | Highest | Worst point avg | EPA limit |
|---|---|---|---|---|
| PFBA Perfluorobutanoic acid |
7 of 10 | 220 ppt | 207 ppt | none |
| PFPeA Perfluoropentanoic acid |
2 of 10 | 6.4 ppt | 5.7 ppt | none |
Not detected: PFDA, HFPO-DA, ADONA, 9Cl-PF3ONS, 11Cl-PF3OUdS, PFUnA, PFDoA, 8:2 FTS, PFOA, PFOS, PFNA, PFHxA, PFHpA, 4:2 FTS, PFBS, PFMPA, PFMBA, PFEESA, NFDHA, PFPeS, PFHpS, PFTA, PFTrDA, 6:2 FTS, PFHxS, NEtFOSAA, NMeFOSAA.
Lithium, tested in the same program: not detected.
What the EPA limits mean here
In April 2024 EPA set enforceable limits of 4 ppt for PFOA and PFOS, 10 ppt each for PFHxS, PFNA and GenX, and a hazard index of 1 for mixtures. Utilities were given until 2029 to comply. In May 2026 EPA proposed keeping only the PFOA and PFOS limits and moving that deadline to 2031. Until that proposal is final, the 2024 limits stand.
Compliance is judged on a running annual average at each entry point, so we show the average at this system's worst sampling point next to its single highest result. UCMR 5 results do not by themselves put a utility in or out of compliance.
What you can do at home
Levels here are under EPA's limits, so no treatment is required. If you want them lower anyway, a certified reverse osmosis system under the sink handles drinking water, and a whole-house carbon filter also takes out the chlorine or chloramine your utility adds.
Other systems in Minnesota
- Mankato none detected
- Moorhead 1 PFAS detected
- Shakopee 4 PFAS detected
- Richfield 1 PFAS detected
- Saint Louis Park 1 PFAS detected
- Roseville 1 PFAS detected
All 196 tested systems in Minnesota
ZIP codes served
55016
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Cite this page
Well & Tap. "PFAS in Cottage Grove water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID MN1820004. https://wellandtap.com/pfas/minnesota/cottage-grove/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID MN1820004). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.