Sinkhole risk in Chittenden County, VT: 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: 31%
At or near the surface: 0%
Buried under cover: 31%

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 169 of Chittenden County's 537 square miles on soluble rock. With about 170,851 residents (318 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 602 map points about 0.9 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Chittenden County

The nearest county rated sinkhole country is Union County, PA, about 315 miles southwest. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Lamoille County, VT 24 mi northeast · 0% at surface
Grand Isle County, VT 26 mi northwest · 1% at surface
Washington County, VT 26 mi southeast · 0% at surface
Franklin County, VT 28 mi north · under 1% at surface
Addison County, VT 30 mi south · under 1% at surface
Clinton County, NY 37 mi northwest · under 1% at surface

Which formation it is

The largest mapped soluble unit here is the Dunham Dolomite (dolostone (dolomite)), Cambrian in age, covering about 4% of the county. Next is the Winooski Dolomite at 4%.

Against the rest of Vermont

Chittenden County ranks 8 of 14 in Vermont for soluble rock at the surface, and sits above 0% of US counties on that measure.