Is there PFAS in Stillwater tap water?

Yes, and above the federal limit. The highest PFOA or PFOS reading was 8.1 parts per trillion, against a limit of 4.

Stillwater is a public water system in Minnesota, serving more than 10,000 people. The EPA required almost every system in the country to test for 29 PFAS compounds and published every result. These are that system’s own readings, not an estimate and not ours.

Every compound tested, 5 of 29 found

CompoundHighest readingFederal limitDetected in
PFBA118 pptno federal limit15 of 15 samples
PFOS8.1 ppt4 ppt3 of 15 samples
PFHxS7.2 ppt10 pptEPA has proposed withdrawing this limit3 of 15 samples
PFOA5.2 ppt4 ppt3 of 15 samples
PFPeA4.5 pptno federal limit6 of 15 samples
11Cl-PF3OUdSnot detectedno federal limit0 of 15 samples
4:2 FTSnot detectedno federal limit0 of 15 samples
6:2 FTSnot detectedno federal limit0 of 15 samples
8:2 FTSnot detectedno federal limit0 of 15 samples
9Cl-PF3ONSnot detectedno federal limit0 of 15 samples
ADONAnot detectedno federal limit0 of 15 samples
HFPO-DAnot detected10 pptEPA has proposed withdrawing this limit0 of 15 samples
NEtFOSAAnot detectedno federal limit0 of 15 samples
NFDHAnot detectedno federal limit0 of 15 samples
NMeFOSAAnot detectedno federal limit0 of 15 samples
PFBSnot detectedno federal limit0 of 15 samples
PFDAnot detectedno federal limit0 of 15 samples
PFDoAnot detectedno federal limit0 of 15 samples
PFEESAnot detectedno federal limit0 of 15 samples
PFHpAnot detectedno federal limit0 of 15 samples
PFHpSnot detectedno federal limit0 of 15 samples
PFHxAnot detectedno federal limit0 of 15 samples
PFMBAnot detectedno federal limit0 of 15 samples
PFMPAnot detectedno federal limit0 of 15 samples
PFNAnot detected10 pptEPA has proposed withdrawing this limit0 of 15 samples
PFPeSnot detectedno federal limit0 of 15 samples
PFTAnot detectedno federal limit0 of 15 samples
PFTrDAnot detectedno federal limit0 of 15 samples
PFUnAnot detectedno federal limit0 of 15 samples

Every row is a compound the EPA required this system to test for, whether it was found or not. Readings are the highest single result the system reported. Compliance is judged on an annual average, so one high sample is not by itself a violation. “Not detected” means below the level the laboratory method can measure, which is not the same as zero. Last sample 6/2/2025.

What actually removes it

Boiling does not remove PFAS and concentrates it. Reverse osmosis and certified activated carbon do. These are the highest-graded filters in our database, scored 0 to 100 on the chemistry of the filter itself.

All water filter grades →

ZIP codes this system serves

55082

Other systems in Minnesota

Source, the EPA’s fifth Unregulated Contaminant Monitoring Rule, final dataset published 2026-10-15. Original data → Figures are the system’s own reported results. Water quality changes, and a result from the monitoring period is not a statement about what is in the tap today.