Sinkhole risk in Bucks 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%

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 12 of Bucks County's 604 square miles on soluble rock, 12 of them with the rock at or near the surface. With about 650,131 residents (1,076 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 406 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Bucks County

The nearest county rated sinkhole country is Union County, PA, about 111 miles northwest. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Montgomery County, PA 16 mi southwest · 5% at surface
Hunterdon County, NJ 19 mi northeast · 5% at surface
Mercer County, NJ 22 mi east · 0% at surface
Philadelphia County, PA 23 mi south · 0% at surface
Somerset County, NJ 30 mi northeast · under 1% at surface
Northampton County, PA 31 mi north · 33% at surface

The rock underneath

The largest mapped soluble unit here is the Leithsville Formation (dolostone (dolomite)), Cambrian in age, covering about 1% of the county. Next is the Allentown Formation at under 1%.

Against the rest of Pennsylvania

Bucks County ranks 44 of 67 in Pennsylvania for soluble rock at the surface, and sits above 58% of US counties on that measure.