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Is there PFAS in Frederick Water water?

Yes, at low levels. 1 PFAS was detected, all below EPA's 2024 limits.

Frederick Water Serves 46,206 people · 8 PFOA samples from 2 sampling points · Nov 2024 to Aug 2025 PFAS found, below EPA limits
PFOA Perfluorooctanoic acid not detected
EPA 4
PFOS Perfluorooctanesulfonic acid not detected
EPA 4
Hazard index GenX, PFBS, PFNA, PFHxS combined not detected
EPA 1

Also detected, no federal limit: PFBS.

Averages are for the worst sampling point, with non-detects counted as zero. Source: EPA UCMR 5.

Frederick Water is a public water system drawing on surface water, based in Winchester, Virginia, serving about 46,206 people, including Winchester, Clear Brook, Front Royal, Stephens City, Stephenson, White Post. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 8 times across 2 sampling points between Nov 2024 and Aug 2025.

Every PFAS detected

PFAS Detected Highest Worst point avg EPA limit
PFBS
Perfluorobutanesulfonic acid
5 of 8 6.9 ppt 4.9 ppt none

Not detected: PFMBA, PFEESA, NFDHA, PFPeS, PFHpS, PFMPA, 4:2 FTS, PFPeA, PFBA, 6:2 FTS, HFPO-DA, 8:2 FTS, ADONA, PFHxS, PFTA, PFTrDA, NEtFOSAA, NMeFOSAA, PFHpA, 11Cl-PF3OUdS, PFNA, 9Cl-PF3ONS, PFUnA, PFHxA, PFDoA, PFDA, PFOA, PFOS.

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 Virginia

All 171 tested systems in Virginia

ZIP codes served

22602 22603 22624 22630 22655 22656 22663

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 Frederick Water water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID VA2069250. https://wellandtap.com/pfas/virginia/frederick-water/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID VA2069250). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.