Well Water Nerd

PFNA in Maine well water

In Maine, 2% of 3,566 tested private well samples exceeded the EPA limit for PFNA (10 ng/L).

PFNA is a long-chain forever chemical found near industrial sites and firefighting foam. It is linked to immune and developmental effects and high cholesterol. New Hampshire set its own limit in 2019.

By county, from individual samples

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

CountySamplesDetectedAbove EPA limitMedianHighest
Somerset58041%7%01,830 ng/L
Kennebec45021%4%0220 ng/L
Waldo40113%3%01,580 ng/L
Lincoln11024%<1%021.2 ng/L
Penobscot29412%<1%0158 ng/L
York3856%<1%011.6 ng/L
Washington3617%0%03.4 ng/L
Knox3611%0%01.95 ng/L
Hancock5810%0%02.4 ng/L
Aroostook1139%0%02.51 ng/L
Cumberland5739%0%07.69 ng/L
Piscataquis307%0%00.508 ng/L
Oxford724%0%00.905 ng/L
Androscoggin2144%0%02.85 ng/L
Sagadahoc1702%0%00.826 ng/L

Sources

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