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Well & TapHome Water Treatment Database

Is there PFAS in City of Westminster water?

Yes. EPA's final UCMR 5 results show City of Westminster averaged 11.4 ppt of PFOA at its worst sampling point, 2.9 times the EPA limit of 4 ppt.

City of Westminster Serves 35,256 people · 28 PFOA samples from 10 sampling points · Jan 2023 to Sep 2025 Average above an EPA limit
PFOA Perfluorooctanoic acid 11.4 ppt avg · max 12.4
EPA 4
PFOS Perfluorooctanesulfonic acid 6.7 ppt avg · max 6.9
EPA 4
PFHxS Perfluorohexanesulfonic acid 3.8 ppt avg · max 4.2
EPA 10
Hazard index GenX, PFBS, PFNA, PFHxS combined 0.4 avg · max 0.4
EPA 1

Also detected, no federal limit: PFPeA, PFHxA, PFBA, PFBS, PFHpA.

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

City of Westminster is a public water system drawing on surface water, based in Westminster, Maryland, serving about 35,256 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 28 times across 10 sampling points between Jan 2023 and Sep 2025.

Every PFAS detected

PFAS Detected Highest Worst point avg EPA limit
PFPeA
Perfluoropentanoic acid
12 of 28 66.7 ppt 59.0 ppt none
PFHxA
Perfluorohexanoic acid
11 of 28 24.6 ppt 23.9 ppt none
PFBA
Perfluorobutanoic acid
4 of 28 20.1 ppt 19.5 ppt none
PFOA
Perfluorooctanoic acid
10 of 28 12.4 ppt 11.4 ppt 4 ppt
PFBS
Perfluorobutanesulfonic acid
15 of 28 8.6 ppt 8.5 ppt none
PFHpA
Perfluoroheptanoic acid
6 of 28 8.1 ppt 7.7 ppt none
PFOS
Perfluorooctanesulfonic acid
4 of 28 6.9 ppt 6.7 ppt 4 ppt
PFHxS
Perfluorohexanesulfonic acid
7 of 28 4.2 ppt 3.8 ppt 10 ppt

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

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

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.

Other systems in Maryland

All 83 tested systems in Maryland

ZIP codes served

21157

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 Westminster water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID MD0060015. https://wellandtap.com/pfas/maryland/city-of-westminster/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID MD0060015). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.