SinkholeOdds

Sinkhole risk in Bullitt County, KY: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock
43%
At or near the surface
42%
Buried under cover
1%

The next step for one property

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 129 of Bullitt County's 297 square miles on soluble rock, 125 of them with the rock at or near the surface. With about 85,802 residents (289 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 522 map points about 0.8 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 the signs to look for and how an inspection works.

Counties around Bullitt County

The nearest county rated sinkhole country is Jefferson County, KY, about 15 miles north, close enough that the same rock may run under the county line. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

What Bullitt County is built on

The largest mapped soluble unit here is the Louisville Limestone and Waldron Shale, undivided (limestone), Silurian in age, covering about 13% of the county. Next is the Laurel Dolomite, Osgood Formation, and Brassfield Dolomite, undivided at 11%.

The county also lies over the Illinois 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 Kentucky

Bullitt County ranks 49 of 120 in Kentucky for soluble rock at the surface, and sits above 85% of US counties on that measure.