PFAS above EPA’s limits in Oklahoma.
The short answer
8 utilities serving 250,611 people, as they report it, had a location averaging above a limit, most often PFOS (8) and PFHxS (1). The largest is Broken Arrow Municipal Authority, whose highest PFOS average was 17 ppt, 4.2 times the limit. The furthest above is Kay Co RWD #5 (Dale Water Corp), at 5.1 times the PFOS limit.
These are EPA’s survey results, not violations: the limits take effect April 26, 2029, and compliance will rest on each utility’s own monitoring. EPA has proposed changes to the rule; as of Oct. 13, 2026, none is final.
Utilities above a limit
Largest first. Each one’s highest location average is for the limit it is furthest above, with the single highest sample of the same PFAS; its report has every result.
| Utility | Based in | Serves | Above | Highest location average | Highest single sample |
|---|---|---|---|---|---|
| Broken Arrow Municipal Authority | Broken Arrow | 116,330 | PFOS | PFOS 17 ppt4.2 times the limit | 51 ppt |
| Stillwater Utilities Authority | Stillwater | 53,000 | PFOS | PFOS 6.1 ppt1.5 times the limit | 8.6 ppt |
| Wagoner Co. RWD #4 | Broken Arrow | 37,658 | PFOS | PFOS 17 ppt4.2 times the limit | 30 ppt |
| Ponca City Mun Water | Ponca City | 27,155 | PFOS | PFOS 6.8 ppt1.7 times the limit | 8.1 ppt |
| Mayes Co RWD # 2 | Chouteau | 6,280 | PFOS | PFOS 4.4 ppt1.1 times the limit | 18 ppt |
| Tri - County RWD #2 | Earlsboro | 5,172 | PFOS, PFHxS | PFHxS 22 ppt2.2 times the limit | 22 ppt |
| Wagoner Co. RWD #5 | Coweta | 4,251 | PFOS | PFOS 15 ppt3.8 times the limit | 34 ppt |
| Kay Co RWD #5 (Dale Water Corp) | Newkirk | 765 | PFOS | PFOS 21 ppt5.1 times the limit | 23 ppt |
5 more utilities in Oklahoma had a single sample above a limit but no location average above, so they are not listed; each report shows the sample.
Results: EPA UCMR 5 occurrence data, file of Oct. 15, 2026, samples from Jan. 3, 2023 to June 17, 2026, averaged by sampling location as EPA’s final UCMR 5 data summary does. Every state, and the full data as a CSV; how this list is made. People served is what each utility reports.
Where to go next
- Broken Arrow Municipal Authority’s reportEvery PFAS result with its dates, and the certification claim that handles each.Open the report
- Every stateThe national list, the largest utilities above a limit, and the data to download.PFAS above EPA’s limits
- Filters certified for PFASRanked by certification and what they cost over five years.Best water filters for PFAS