What EPA's radon map says about Greenbrier County

Greenbrier County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Greenbrier County ranks higher in radon potential than 86% of rated counties (the 86th percentile).

Greenbrier County by the numbers

About 31,851 people live in Greenbrier County, West Virginia, spread over 1,019.819 square miles. Population density there runs about 31 people per square mile. Among counties sharing Greenbrier County's EPA zone, it outranks 58% of them by population. EPA's geology-based Region 3 groups Greenbrier County with 244 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Greenbrier 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 Greenbrier 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 Greenbrier County

Mitigation cost doesn't depend on Greenbrier County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find West Virginia's state radon program

Greenbrier County's test kit answers today; a Airthings radon monitor keeps answering for Greenbrier County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.