Sinkhole risk in Sullivan County, NY: No soluble rock mapped

What to do about a house in Sullivan County

No soluble bedrock is mapped here, so natural sinkholes are unlikely. Collapses from broken pipes or old mines are a separate risk.

That works out to roughly 4 of Sullivan County's 968 square miles on soluble rock. With about 80,450 residents (83 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 241 map points about 2.0 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 Sullivan County

The nearest county rated sinkhole country is Union County, PA, about 130 miles southwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

• Wayne County, PA 27 mi west · 0% at surface
• Pike County, PA 30 mi southwest · 0% at surface
• Ulster County, NY 30 mi northeast · 0% at surface
• Orange County, NY 33 mi southeast · 0% at surface
• Delaware County, NY 34 mi north · 0% at surface
• Sussex County, NJ 40 mi south · 0% at surface

What Sullivan County is built on

The largest mapped soluble unit here is the Helderberg Group (limestone), Lower Devonian in age, covering about under 1% of the county.

Against the rest of New York

Sullivan County ranks 53 of 62 in New York for soluble rock at the surface, and sits above 0% of US counties on that measure.

• New York County under 1%
• St. Lawrence County under 1%
• Saratoga County under 1%
• Cayuga County under 1%
• Clinton County under 1%