Well Water Nerd

PFHxS in Maine well water

In Maine, 1% of 3,562 tested private well samples exceeded the EPA limit for PFHxS (10 ng/L).

PFHxS comes mainly from firefighting foam and persists in the body longer than most PFAS. It is linked to thyroid and immune effects. Wells near airports, fire stations and training grounds are most at risk.

By county, from individual samples

Public monitoring samples against the EPA limit (10 ng/L); counties with at least 30 samples.

CountySamplesDetectedAbove EPA limitMedianHighest
Washington3625%6%0123 ng/L
Franklin4416%5%022.4 ng/L
Somerset57536%2%0489 ng/L
Oxford7218%1%012 ng/L
Penobscot29426%1%054.6 ng/L
Sagadahoc17022%1%011.7 ng/L
York38536%1%031.2 ng/L
Lincoln11035%<1%022.2 ng/L
Aroostook11323%<1%010.4 ng/L
Waldo40118%<1%044 ng/L
Cumberland57343%<1%024 ng/L
Kennebec45027%<1%019 ng/L
Androscoggin21522%<1%019.7 ng/L
Knox3636%0%07.02 ng/L
Hancock5814%0%01.04 ng/L

Sources

  • Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. PFHxS counts and shares are listed on each county and town page with their sources.