What EPA's radon map says about Clay County

Clay County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Clay County in the 38th percentile nationally for radon potential — higher than 38% of the counties EPA has rated.

Clay County by the numbers

About 7,689 people live in Clay County, West Virginia, spread over 341.954 square miles. Population density there runs about 22 people per square mile. Among counties sharing Clay County's EPA zone, it outranks 15% of them by population. Clay County falls in EPA Radon Region 3, one of 245 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

EPA's Zone 2 rating for Clay County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Middle-of-the-pack doesn't mean risk-free for any one Clay County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Clay County

Mitigation cost doesn't depend on Clay 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

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

More on how this number was built

Clay County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Clay County carries, the zone explainer covers what it does and doesn't tell you about any one house.