PFAS above EPA’s limits in Ohio.
The short answer
35 utilities serving 1.5 million people, as they report it, had a location averaging above a limit, most often PFOS (21) and PFOA (17). The largest is Cincinnati Public Water System, whose highest PFOS average was 5.2 ppt, 1.3 times the limit. The furthest above is McDonald Village PWS, at 4.4 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 |
|---|---|---|---|---|---|
| Cincinnati Public Water System | Cincinnati | 800,000 | PFOS | PFOS 5.2 ppt1.3 times the limit | 6.1 ppt |
| Montgomery County Water Services 1 PWS | Kettering | 150,207 | PFOS | PFOS 4.8 ppt1.2 times the limit | 9.6 ppt |
| Dayton Public Water System | Dayton | 141,407 | PFOS | PFOS 7.5 ppt1.9 times the limit | 10 ppt |
| Clermont Public Water System | Batavia | 133,059 | PFOS | PFOS 9.2 ppt2.3 times the limit | 10 ppt |
| Western Water Company | Morrow | 39,508 | PFOS | PFOS 9.8 ppt2.5 times the limit | 14 ppt |
| Gallia Co Rural Water Association | Gallipolis | 20,995 | PFOA | PFOA 7.5 ppt1.9 times the limit | 7.5 ppt |
| Springboro PWS | Springboro | 19,263 | PFOA, PFOS | PFOA 5.7 ppt1.4 times the limit | 6.9 ppt |
| Marietta City PWS | Marietta | 18,707 | PFOA, PFOS | PFOS 5.0 ppt1.2 times the limit | 5.6 ppt |
| Wright - Patterson AFB Area A PWS | Vandalia | 16,551 | PFOS | PFOS 5.0 ppt1.2 times the limit | 5.0 ppt |
| Indian Hill City PWS | Cincinnati | 15,000 | PFOS | PFOS 12 ppt2.9 times the limit | 12 ppt |
| Loveland City PWS | Loveland | 12,800 | PFOS | PFOS 16 ppt4 times the limit | 16 ppt |
| Wright - Patterson AFB Area B PWS | Vandalia | 11,034 | PFOA, PFOS, PFHxS, Hazard Index | PFOS 14 ppt3.5 times the limit | 14 ppt |
| City of Cambridge | Cambridge | 10,520 | PFOA | PFOA 5.2 ppt1.3 times the limit | 5.6 ppt |
| Trumbull Co. - Southeast PWS | Vienna | 9,931 | PFOS | PFOS 6.4 ppt1.6 times the limit | 9.1 ppt |
| Bellbrook Water Works | Bellbrook | 9,475 | PFOS | PFOS 5.0 ppt1.2 times the limit | 5.7 ppt |
| Guernsey Co. Water Dept. | Cambridge | 8,891 | PFOA | PFOA 7.8 ppttwice the limit | 9.8 ppt |
| Canfield City PWS | Canfield | 7,706 | PFOS | PFOS 11 ppt2.8 times the limit | 12 ppt |
| Warren Comm W and S Assn 2 | Marietta | 7,215 | PFOA | PFOA 10 ppt2.5 times the limit | 20 ppt |
| Gallipolis PWS | Gallipolis | 7,134 | PFOA | PFOA 6.4 ppt1.6 times the limit | 7.2 ppt |
| Martins Ferry Public Water System | Martins Ferry | 6,980 | PFOA | PFOA 5.8 ppt1.5 times the limit | 6.1 ppt |
| Milford City PWS | Milford | 6,700 | PFOS | PFOS 7.8 ppttwice the limit | 7.8 ppt |
| Leading Creek Conservancy District | Rutland | 6,663 | PFOA | PFOA 6.7 ppt1.7 times the limit | 7.6 ppt |
| Barnesville | Barnesville | 6,500 | PFOA | PFOA 6.5 ppt1.6 times the limit | 8.1 ppt |
| Trumbull Co. - Howland Twp PWS | Vienna | 6,396 | PFOS | PFOS 11 ppt2.6 times the limit | 13 ppt |
| Newton Falls City | Newton Falls | 6,109 | PFOA | PFOA 4.2 ppt1.05 times the limit | 6.7 ppt |
| St. Clairsville, City of PWS | St. Clairsville | 5,097 | PFOA | PFOA 5.2 ppt1.3 times the limit | 6.4 ppt |
| McDonald Village PWS | McDonald | 4,236 | PFOS | PFOS 17 ppt4.4 times the limit | 21 ppt |
| Yellow Springs Village PWS | Yellow Springs | 3,761 | PFOS | PFOS 4.6 ppt1.1 times the limit | 9.2 ppt |
| Jackson/Milton Metro Water District PWS | Youngstown | 3,728 | PFOS | PFOS 7.2 ppt1.8 times the limit | 8.5 ppt |
| Shadyside Public Water System | Barnesville | 3,689 | PFOA | PFOA 5.2 ppt1.3 times the limit | 6.0 ppt |
| Lordstown Village PWS | Lordstown | 3,515 | PFOS | PFOS 12 ppt2.9 times the limit | 16 ppt |
| Caldwell Village PWS | Caldwell | 3,300 | PFOA | PFOA 8.4 ppt2.1 times the limit | 13 ppt |
| Putnam Community Water Association PWS | Marietta | 2,744 | PFOA | PFOA 15 ppt3.8 times the limit | 17 ppt |
| Bethel Village PWS | Bethel | 2,620 | PFOA | PFOA 7.5 ppt1.9 times the limit | 7.9 ppt |
| Dayton VA Bldg 410 | Dayton | 125 | PFOS | PFOS 8.6 ppt2.1 times the limit | 11 ppt |
18 more utilities in Ohio 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
- Cincinnati Public Water System’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