Sinkhole risk in Greene County, PA: 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: 8%
At or near the surface: 8%
Buried under cover: 0%

What to do about a house in Greene County

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

That works out to roughly 45 of Greene County's 576 square miles on soluble rock, 45 of them with the rock at or near the surface. With about 33,960 residents (59 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 358 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Greene County

The nearest county rated sinkhole country is Winchester city, VA, about 119 miles east. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Monongalia County, WV 17 mi southeast · 12% at surface
Marion County, WV 24 mi south · 15% at surface
Marshall County, WV 24 mi west · 4% at surface
Washington County, PA 24 mi north · 31% at surface
Ohio County, WV 27 mi northwest · 22% at surface
Wetzel County, WV 28 mi southwest · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Monongahela Group (limestone), Pennsylvanian in age, covering about 8% of the county.

The county also lies over the Michigan Basin; Ohio Basin; Appalachian Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Pennsylvania

Greene County ranks 33 of 67 in Pennsylvania for soluble rock at the surface, and sits above 66% of US counties on that measure.