Warren County, NJ radon potential

Warren County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Warren County ranks higher in radon potential than 94% of rated counties (the 94th percentile).

Warren County by the numbers

Warren County, New Jersey is home to about 112,031 people across 356.541 square miles. That works out to roughly 314 people per square mile. Within its own EPA zone, Warren County is bigger by population than 83% of the counties that share it. EPA's geology-based Region 2 groups Warren County with 82 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Warren County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. Some Warren County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

Testing and mitigation in Warren 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 Warren County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Warren County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

Where Warren County's figures come from

Warren 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.