Maine Well Water Guide — Arsenic, PFAS, Testing & Community Data

Maine has the highest percentage of residents on private wells of any state in the Northeast — roughly 400,000 households. Arsenic is in the bedrock. PFAS is in the groundwater. Nobody is testing your water but you.

The Numbers

1 in 10 Maine wells exceed the EPA arsenic limit

~400K Maine households on private wells

700+ sludge sites being investigated for PFAS

FREE arsenic testing through Maine CDC

Why Maine Is Different

In the Southwest, well water problems are about quantity — aquifers running dry. In Maine, the problem is quality. There's plenty of water. The question is what's in it.

Maine faces a double threat that no other state has in quite this combination: naturally occurring arsenic in the bedrock that's been there for millions of years, and man-made PFAS contamination from decades of spreading treated sewage sludge on farmland. Both are invisible. Both require testing to detect. And both are serious health risks.

Arsenic

1 in 10 Maine wells exceeds the EPA limit. Naturally occurring in bedrock. Tasteless, odorless, colorless. A Class I carcinogen. Free testing available.

PFAS

Maine's sludge crisis: decades of spreading treated sewage on farmland put "forever chemicals" in the groundwater. Farms shut down. Wells contaminated. Investigation ongoing.

Radon

Maine's granite bedrock produces radon that dissolves in well water and enters your home's air. A known lung cancer risk from the same geology that causes arsenic.

Uranium & Manganese

Co-occur with arsenic in Maine's bedrock. Uranium affects kidneys. Manganese linked to neurological effects in children. Test if arsenic is elevated.

Find Your Community

We've researched water quality conditions for communities across Maine that rely on private wells. Each guide covers local geology, specific contaminants, testing recommendations, and resources.