Sinkhole risk in Knox 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: 11%
At or near the surface: under 1%
Buried under cover: 10%

What to do about a house in Knox County

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

That works out to roughly 40 of Knox County's 365 square miles on soluble rock, 2 of them with the rock at or near the surface. With about 40,981 residents (112 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 322 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Knox County

The nearest county rated sinkhole country is Union County, PA, about 460 miles southwest. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Lincoln County, ME 24 mi west · 1% at surface
Waldo County, ME 30 mi north · 0% at surface
Sagadahoc County, ME 41 mi west · 0% at surface
Kennebec County, ME 44 mi northwest · 0% at surface
Hancock County, ME 49 mi northeast · 0% at surface
Androscoggin County, ME 59 mi west · 0% at surface

What Knox County is built on

The largest mapped soluble unit here is the Ordovician unnamed sandstone (sandstone), Ordovician in age, covering about 5% of the county. Next is the Devonian - Ordovician Bucksport Formation at 4%.

Against the rest of Maine

Knox County ranks 2 of 16 in Maine for soluble rock at the surface, and sits above 53% of US counties on that measure.