Southampton County, VA: EPA's radon zone, explained

Southampton County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Rank it against the rest of the country and Southampton County lands in the 12th percentile for radon potential.

How Southampton County compares

Southampton County, Virginia is home to about 17,941 people across 599.249 square miles. That works out to roughly 30 people per square mile. By population, Southampton County is the 666th largest of every county sharing its EPA zone — the 35th percentile by population within that zone. EPA's geology-based Region 3 groups Southampton County with 244 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

A Zone 3 county like Southampton County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Even at Zone 3, Southampton County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in Southampton County

For a Southampton County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Virginia's state radon program

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

Where Southampton County's figures come from

Southampton 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.