Sinkhole risk in Androscoggin County, ME: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock: 25%
At or near the surface: 0%
Buried under cover: 25%

What this means before you buy

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 117 of Androscoggin County's 468 square miles on soluble rock. With about 115,272 residents (246 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 520 map points about 0.9 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 25% under cover still counts, and how these percentages are measured.

Counties around Androscoggin County

The nearest county rated sinkhole country is Union County, PA, about 413 miles southwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Sagadahoc County, ME 25 mi southeast · 0% at surface
Cumberland County, ME 26 mi south · 0% at surface
Kennebec County, ME 28 mi northeast · 0% at surface
Oxford County, ME 34 mi northwest · 0% at surface
Lincoln County, ME 36 mi east · 1% at surface
Carroll County, NH 54 mi west · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Silurian Sangerville Formation Patch Mountain member (marble), Silurian in age, covering about 22% of the county. Next is the Silurian Sangerville Formation Anasagunticook member at 2%.

Against the rest of Maine

Androscoggin County ranks 4 of 16 in Maine for soluble rock at the surface, and sits above 0% of US counties on that measure.