Sussex County, NJ radon potential

EPA's own radon map rates Sussex County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Rank it against the rest of the country and Sussex County lands in the 96th percentile for radon potential.

How Sussex County compares

Sussex County, New Jersey is home to about 147,444 people across 518.493 square miles. That works out to roughly 284 people per square mile. Within its own EPA zone, Sussex County is bigger by population than 87% of the counties that share it. EPA's geology-based Region 2 groups Sussex County with 82 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Sussex County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. Being in Zone 1 raises the odds Sussex County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Next steps for a home in Sussex County

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find New Jersey's state radon program

For Sussex County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Sussex County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Sussex County's figures come from

Sussex County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.