Some. At least one sample reached an EPA limit, but the average at every sampling point stayed below it.
Also detected, no federal limit: PFBA.
Dubuque Water Works is a public water system drawing on groundwater, based in Dubuque, Iowa, serving about 59,667 people, including Dubuque, Peosta. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 2 times across 1 sampling point between Jul 2023 and Feb 2024.
| PFAS | Detected | Highest | Worst point avg | EPA limit |
|---|---|---|---|---|
| PFBA Perfluorobutanoic acid |
2 of 2 | 13.0 ppt | 10.5 ppt | none |
| PFOA Perfluorooctanoic acid |
1 of 2 | 5.1 ppt | 2.6 ppt | 4 ppt |
Not detected: NFDHA, HFPO-DA, 6:2 FTS, 4:2 FTS, 8:2 FTS, PFMPA, PFPeA, PFTA, PFEESA, ADONA, PFPeS, NEtFOSAA, PFMBA, PFOS, PFHpS, NMeFOSAA, PFTrDA, PFHpA, PFBS, PFNA, 9Cl-PF3ONS, PFDA, PFDoA, PFHxA, PFUnA, 11Cl-PF3OUdS, PFHxS.
Lithium, tested in the same program: not detected.
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.
Two routes work for PFAS. For drinking and cooking water only, a reverse osmosis system certified to NSF/ANSI 58 with a PFOA/PFOS reduction claim is the cheapest proven option. To treat every tap and shower, a whole-house carbon system with enough contact time works, but check that the maker has PFAS test data, not just a marketing claim. See the best filters for PFAS and how PFAS removal works.
All 152 tested systems in Iowa
52001 52002 52003 52068
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Well & Tap. "PFAS in Dubuque Water Works water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID IA3126052. https://wellandtap.com/pfas/iowa/dubuque-water-works/
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID IA3126052). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
