Sinkhole risk in Schuylkill 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: 2%
At or near the surface: 2%
Buried under cover: 0%

What to do about a house in Schuylkill County

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

That works out to roughly 16 of Schuylkill County's 779 square miles on soluble rock, 16 of them with the rock at or near the surface. With about 144,523 residents (186 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 521 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Schuylkill County

The nearest county rated sinkhole country is Union County, PA, about 47 miles west. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Berks County, PA 25 mi southeast · 22% at surface
Columbia County, PA 26 mi north · 4% at surface
Lebanon County, PA 26 mi southwest · 31% at surface
Northumberland County, PA 28 mi west · 26% at surface
Carbon County, PA 31 mi northeast · under 1% at surface
Montour County, PA 32 mi northwest · 40% at surface

What Schuylkill County is built on

The largest mapped soluble unit here is the Onondaga Formation through Poxono Island Formation, undivided (shale), Devonian and Silurian in age, covering about 2% of the county. Next is the Decker Formation through Poxono Island Formation, undivided at under 1%.

Against the rest of Pennsylvania

Schuylkill County ranks 43 of 67 in Pennsylvania for soluble rock at the surface, and sits above 58% of US counties on that measure.