PFAS above EPA’s limits in Maryland.

13 utilities of the 76 EPA tested in Maryland had a sampling location whose PFAS average was above a 2024 limit in its final UCMR 5 data, by EPA’s own method.

The short answer

13 utilities serving 162,211 people, as they report it, had a location averaging above a limit, most often PFOA (12) and PFOS (11). The largest is City of Westminster, whose highest PFOA average was 11 ppt, 2.8 times the limit. The furthest above is Town of Thurmont, at 11 times the PFOS limit.

These are EPA’s survey results, not violations: the limits take effect April 26, 2029, and compliance will rest on each utility’s own monitoring. EPA has proposed changes to the rule; as of Oct. 13, 2026, none is final.

Utilities above a limit

Largest first. Each one’s highest location average is for the limit it is furthest above, with the single highest sample of the same PFAS; its report has every result.

Maryland utilities above a 2024 PFAS limit
Utility	Based in	Serves	Above	Highest location average	Highest single sample
City of Westminster	Westminster	35,256	PFOA, PFOS	PFOA 11 ppt2.8 times the limit	12 ppt
City of Salisbury	Salisbury	30,343	PFOS	PFOS 10 ppt2.5 times the limit	20 ppt
City of Aberdeen	Aberdeen	18,006	PFOA, PFOS	PFOS 8.2 ppttwice the limit	8.6 ppt
Town of Elkton	Elkton	15,625	PFOA, PFOS	PFOA 23 ppt5.7 times the limit	23 ppt
Maryland American Water Company	Bel Air	13,200	PFOA, PFOS	PFOA 7.6 ppt1.9 times the limit	9.3 ppt
Town of Mount Airy	Mount Airy	9,890	PFOA, PFOS	PFOA 8.4 ppt2.1 times the limit	13 ppt
City of Taneytown	Taneytown	6,750	PFOA, PFOS	PFOS 10 ppt2.6 times the limit	11 ppt
Town of Hampstead	Hampstead	6,600	PFOA, PFOS	PFOA 9.1 ppt2.3 times the limit	9.1 ppt
Town of Thurmont	Thurmont	6,200	PFOA, PFOS	PFOS 45 ppt11 times the limit	48 ppt
Town of Poolesville	Poolesville	6,005	PFOA, PFOS	PFOS 6.0 ppt1.5 times the limit	6.5 ppt
Town of Middletown	Middletown	5,132	PFOA, PFOS	PFOS 6.4 ppt1.6 times the limit	6.7 ppt
Town of Manchester	Manchester	4,954	PFOA	PFOA 4.4 ppt1.1 times the limit	4.7 ppt
Boonsboro - Keedysville	Boonsboro	4,250	PFOA	PFOA 5.9 ppt1.5 times the limit	6.7 ppt

1 more utility in Maryland had a single sample above a limit but no location average above, so it is not listed; each report shows the sample.

Results: EPA UCMR 5 occurrence data, file of Oct. 15, 2026, samples from Jan. 3, 2023 to June 17, 2026, averaged by sampling location as EPA’s final UCMR 5 data summary does. Every state, and the full data as a CSV; how this list is made. People served is what each utility reports.

Utilities above a limit

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