Sinkhole risk in Ocean County, NJ: 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: 1%
At or near the surface: 1%
Buried under cover: 0%

What to do about a house in Ocean County

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 8 of Ocean County's 628 square miles on soluble rock, 8 of them with the rock at or near the surface. With about 666,434 residents (1,061 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 603 map points about 1.0 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 Ocean County

The nearest county rated sinkhole country is Union County, PA, about 165 miles northwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Burlington County, NJ 21 mi west · 4% at surface
Monmouth County, NJ 30 mi north · 13% at surface
Atlantic County, NJ 34 mi southwest · 0% at surface
Mercer County, NJ 37 mi northwest · 0% at surface
Camden County, NJ 38 mi west · 6% at surface
Middlesex County, NJ 40 mi north · 0% at surface

What Ocean County is built on

The largest mapped soluble unit here is the Vincentown Formation (sand), upper Paleocene, Selandian in age, covering about 1% of the county.

Against the rest of New Jersey

Ocean County ranks 9 of 21 in New Jersey for soluble rock at the surface, and sits above 56% of US counties on that measure.