Sinkhole risk in York 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: 10%
At or near the surface: 10%
Buried under cover: 0%

The next step for one property

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

That works out to roughly 94 of York County's 904 square miles on soluble rock, 94 of them with the rock at or near the surface. With about 471,240 residents (521 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 548 map points about 1.3 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 York County

The nearest county rated sinkhole country is Washington County, MD, about 62 miles west. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Adams County, PA 26 mi west · 6% at surface
Lancaster County, PA 27 mi east · 46% at surface
Carroll County, MD 29 mi southwest · 2% at surface
Cumberland County, PA 33 mi northwest · 48% at surface
Baltimore County, MD 34 mi south · 8% at surface
Lebanon County, PA 34 mi northeast · 31% at surface

What York County is built on

The largest mapped soluble unit here is the Conestoga Formation (limestone), Ordovician and Cambrian in age, covering about 3% of the county. Next is the Vintage Formation at 3%.

Against the rest of Pennsylvania

York County ranks 30 of 67 in Pennsylvania for soluble rock at the surface, and sits above 68% of US counties on that measure.