Sinkhole risk in Grainger County, TN: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock: 79%
At or near the surface: 79%
Buried under cover: 0%

What to do about a house in Grainger County

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 220 of Grainger County's 281 square miles on soluble rock, 220 of them with the rock at or near the surface. With about 25,073 residents (89 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 455 map points about 0.8 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Grainger County

The closest county with no soluble rock mapped is Knox County, KY, about 46 miles northwest. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Hamblen County, TN 14 mi east · 99% at surface
Jefferson County, TN 16 mi south · 100% at surface
Claiborne County, TN 18 mi northwest · 75% at surface
Union County, TN 18 mi west · 89% at surface
Hancock County, TN 23 mi northeast · 65% at surface
Knox County, TN 31 mi southwest · 95% at surface

What Grainger County is built on

The largest mapped soluble unit here is the Copper Ridge Dolomite (dolostone (dolomite)), Cambrian in age, covering about 28% of the county. Next is the Maryville Limestone, Rogersville Shale, Rutledge Limestone at 14%.

Against the rest of Tennessee

Grainger County ranks 23 of 95 in Tennessee for soluble rock at the surface, and sits above 94% of US counties on that measure.