Also detected, no federal limit: PFPeA.
Is there PFAS in City of Frederick water?
Yes, at low levels. 1 PFAS was detected, all below EPA's 2024 limits.
City of Frederick is a public water system drawing on surface water, based in Frederick, Maryland, serving about 54,000 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 16 times across 4 sampling points between Mar 2024 and Dec 2024.
Every PFAS detected
| PFAS | Detected | Highest | Worst point avg | EPA limit |
|---|---|---|---|---|
| PFPeA Perfluoropentanoic acid |
1 of 16 | 3.1 ppt | 0.8 ppt | none |
Not detected: 9Cl-PF3ONS, PFHpS, PFPeS, NFDHA, PFEESA, PFMBA, PFMPA, 8:2 FTS, 4:2 FTS, 6:2 FTS, PFBA, ADONA, PFHxA, HFPO-DA, PFDA, PFUnA, 11Cl-PF3OUdS, PFTA, NEtFOSAA, PFTrDA, PFDoA, PFBS, PFOA, PFOS, PFNA, PFHxS, PFHpA, NMeFOSAA.
Lithium, tested in the same program: not detected.
What the EPA limits mean here
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.
What you can do at home
Levels here are under EPA's limits, so no treatment is required. If you want them lower anyway, a certified reverse osmosis system under the sink handles drinking water, and a whole-house carbon filter also takes out the chlorine or chloramine your utility adds.
Other systems in Maryland
- City of Rockville 4 PFAS detected
- Fort George G. Meade none detected
- Crofton-odenton none detected
- Lexington Park none detected
- City of Westminster above an EPA limit
- City of Annapolis none detected
All 83 tested systems in Maryland
ZIP codes served
21701 21702 21703
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Cite this page
Well & Tap. "PFAS in City of Frederick water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID MD0100015. https://wellandtap.com/pfas/maryland/city-of-frederick/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID MD0100015). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.