PFAS test results for Central Ohio water systems, from the federal UCMR 5 testing
Between 2023 and 2025 every community water system serving 3,300 or more people had to test its water for 29 PFAS under the federal Environmental Protection Agency's fifth Unregulated Contaminant Monitoring Rule, known as UCMR 5, and the agency published the final results in August 2026. This page sets out what those results show for the same 22 Central Ohio water systems as the page on lead service lines: where PFOA was found and on which date, the annual averages the agency itself calculated against the 4.0 parts per trillion limit, the other PFAS that turned up, and the fifteen systems where no PFAS was found at all. The agency says plainly that these results do not decide whether any system complies.
Last updated September 2026 · Results are the Environmental Protection Agency's UCMR 5 Data Finder, final data released August 2026, read September 24, 2026 · No prices on this page; the Estimate Builder carries those · Part of the knowledge base
What UCMR 5 was, and what it cannot tell you
The Environmental Protection Agency's Data Finder page describes the program in its own terms. UCMR 5 required monitoring for 29 per- and polyfluoroalkyl substances and lithium in drinking water between 2023 and 2025; every community water system serving 3,300 or more people, and a nationally representative sample of smaller ones, had to monitor during a single 12-month timeframe inside those three years. The final dataset was released in August 2026. The figures below were read from the agency's UCMR 5 Data Finder on September 24, 2026, and are printed in parts per trillion.
The same page sets out the limit and the caution together. On April 10, 2024 the agency announced legally enforceable limits for certain of these PFAS, and the Data Finder lists 4.0 parts per trillion as the regulatory level for both PFOA and PFOS. It then says that UCMR 5 results do not indicate compliance or noncompliance with those limits, because compliance is determined by calculating the running annual average of quarterly results for each sampling location, from compliance monitoring data reported to the state regulator. Because many readers want the comparison anyway, the agency calculated annual averages for the UCMR 5 results where it could and compared them to the limits, for technical assistance only. Those averages are printed below beside every PFOA result. What the federal limits are and where the agency's proposals to change them stand is on the water quality report page.
The seven systems where PFAS was found
| Water system | When it sampled | PFOA: highest single result, and the agency's annual average | Other PFAS found, highest single result |
|---|---|---|---|
| Columbus Public Water System | February to November 2024, three plants | Dublin Road plant 5.3 (November 20, 2024); EPA average 1.325; Hap Cremean and Parsons Avenue none | Dublin Road: PFHxA 18.2, PFBA 17.0, PFPeA 14.2, PFBS 11.1, PFHpA 4.3; Parsons Avenue: PFBA 6.0, PFPeA 3.3 |
| Del-Co Water Company | July 2023 to April 2024, three plants | Olentangy plant 4.2 (July 11, 2023); EPA average 1.05; Alum Creek and East Knox none | Olentangy plant: PFBA 10.7, PFHxA 8.7, PFPeA 6.3, PFBS 4.3 |
| Bexley City | February to November 2023, two entry points | Entry point 1: 5.6 (November 20, 2023) and 4.1 (August 25, 2023); EPA average 2.425 | Entry point 1: PFHxA 12.2, PFBA 11.7, PFPeA 11.4, PFBS 8.3; entry point 2: PFBA 7.2, PFHxA 3.8, PFPeA 3.5 |
| Sanitary District #4 | February to November 2024, at its Columbus interconnection | 7.2 (November 12, 2024); EPA average 1.8 | PFHxA 22.0, PFPeA 17.0, PFBA 17.0, PFBS 11.0, PFHpA 5.4 |
| Newark City | 2023, with one sample in February 2025 | None found | PFBA 9.5 |
| Westerville City | November 2024 to August 2025 | None found | PFBA 5.6 |
| Reynoldsburg City | February to November 2024, at two Columbus connections | None found | PFBA 5.5, at the Hap Cremean connection |
PFOS was not found in any sample from any of the 22 systems. PFOA was found at four: the Columbus system's Dublin Road plant, Del-Co's Olentangy plant, Bexley, and Sanitary District #4, whose samples were taken at its Columbus interconnection. For every one of them the agency's own flag for an annual average above the limit reads no, and its averages run from 1.05 at Del-Co to 2.425 in Bexley. The Columbus figure of 1.325 is the average of four quarters at Dublin Road in which PFOA was found once. The minimum reporting level for PFOA in this testing was 4 parts per trillion, the same number as the limit, so any PFOA result the testing reports at all is at least 4.
The other compounds in the table, PFBA, PFHxA, PFPeA and PFHpA, carry no federal limit; the Data Finder marks them unregulated. As of September 2026, PFBS is marked regulated only as part of the hazard index, a combined measure the agency proposed on May 18, 2026 to rescind together with its limits for PFHxS, PFNA and HFPO-DA. None of PFHxS, PFNA or HFPO-DA was found in any of the 22 systems.
The fifteen systems where none was found
No PFAS of any kind was found in any UCMR 5 sample from Delaware City, Lancaster City, Marysville City, Gahanna City, Licking Regional Water District, Pickerington City, Fairfield County Utilities, Circleville City, Jefferson Water and Sewer District, the Mid-Ohio Water and Sewer District's London and Plain City plants, Pataskala City, Aqua Ohio Blacklick, Canal Winchester City and Granville Village. Gahanna buys its water from Columbus and sampled at its Hap Cremean connection; nothing was found there, while Reynoldsburg's samples at its own Hap Cremean connection showed PFBA twice, at 5.5 and 5.2. Each result is tied to the location the Data Finder names for it, a treatment plant, an entry point or a connection to another system, so a result describes that location, not a tap in a house.
What none of this says about a shower
Scope, plainly. These are a water system's entry-point results, mostly from one year of testing, published by the agency with its own statement that they do not decide compliance. They say nothing about any particular house, any filter or any fixture, and this page gives no health advice. What each system's lead service lines and lead results show is on the page on lead service lines by water system, and who supplies each town is on the page on water and sewer providers town by town.
The short version. In the federal UCMR 5 testing of 2023 to 2025, as read on September 24, 2026, PFOS was not found at any of 22 Central Ohio water systems, and PFOA was found at four: Columbus's Dublin Road plant at 5.3, Del-Co's Olentangy plant at 4.2, Bexley at 5.6 and 4.1, and Sanitary District #4 at 7.2. The agency's own annual averages for those four run from 1.05 to 2.425 against a limit of 4.0, and its flag for an average above the limit reads no for every one. Fifteen of the 22 found no PFAS at all. The agency says these results do not indicate compliance or noncompliance.
Sources
Every figure, date and quotation on this page comes from one of these documents, read on the date given. Where two of them disagree, the page says so.
- United States Environmental Protection Agency, Fifth Unregulated Contaminant Monitoring Rule Data Finder, final data released August 2026, queried September 24, 2026.
- United States Environmental Protection Agency, Fifth Unregulated Contaminant Monitoring Rule, undated; read September 2026.
Common questions
Which Central Ohio water systems found PFOA in the federal UCMR 5 testing?
Four of the 22 systems read for the page, in results the Environmental Protection Agency published in August 2026: the Columbus system at its Dublin Road plant, 5.3 parts per trillion on November 20, 2024; Del-Co Water at its Olentangy plant, 4.2 on July 11, 2023; Bexley, 5.6 on November 20, 2023 and 4.1 on August 25, 2023; and Sanitary District #4 at its Columbus interconnection, 7.2 on November 12, 2024. The agency says UCMR 5 results do not indicate compliance or noncompliance with the limits.
Did any Central Ohio water system average above the federal PFOA limit in UCMR 5?
No. The Environmental Protection Agency calculated annual averages for UCMR 5 results where it could and compared them to the 4.0 parts per trillion limit, for technical assistance only. For the four Central Ohio systems where PFOA was found, its averages are 1.05 at Del-Co, 1.325 at Columbus's Dublin Road plant, 1.8 at Sanitary District #4 and 2.425 in Bexley, and its flag for an average above the limit reads no for each of them.
Was PFOS found in Central Ohio drinking water in the UCMR 5 testing?
Not at any of the 22 Central Ohio community water systems read for the page. The Environmental Protection Agency's UCMR 5 Data Finder, final data released August 2026, shows no PFOS result at or above its minimum reporting level of 4 parts per trillion in any sample from the Columbus system, Del-Co, Newark, Delaware, Lancaster, Westerville, Reynoldsburg, Marysville, Gahanna, Bexley or any of the smaller systems in the set.
What is UCMR 5 and which water systems had to do it?
It is the Environmental Protection Agency's fifth Unregulated Contaminant Monitoring Rule. It required monitoring for 29 PFAS and lithium in drinking water between 2023 and 2025, by every community water system serving 3,300 or more people and a nationally representative sample of smaller ones, each during a single 12-month timeframe. The agency released the final dataset in August 2026 and publishes it through its UCMR 5 Data Finder, which can be searched by water system.
Which Central Ohio water systems found no PFAS at all in UCMR 5?
Fifteen of the 22 read for the page: Delaware City, Lancaster, Marysville, Gahanna, Licking Regional Water District, Pickerington, Fairfield County Utilities, Circleville, Jefferson Water and Sewer District, the Mid-Ohio Water and Sewer District plants serving London and Plain City, Pataskala, Aqua Ohio Blacklick, Canal Winchester and Granville. No PFAS of any kind was reported at or above the minimum reporting levels in any of their UCMR 5 samples.
Does a water system's UCMR 5 result tell me what is in my shower water?
No. Each UCMR 5 result is tied to a location the Environmental Protection Agency's Data Finder names as a treatment plant, an entry point or a connection to another system, mostly over one year of testing, and the Environmental Protection Agency says the results do not indicate compliance or noncompliance with its limits. They describe a plant or a connection, not the water at any particular tap, and they say nothing about a house's own pipes, fixtures or filters.
See your actual price in about two minutes
Pick your shower, choose real products with real model numbers, and watch the number move. No phone number required, and nobody will call unless you ask.