What EPA's radon map says about McDowell County

McDowell County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts McDowell County in the 11th percentile nationally for radon potential — higher than 11% of the counties EPA has rated.

How McDowell County compares

About 17,147 people live in McDowell County, West Virginia, spread over 533.459 square miles. Averaged across its land area, McDowell County runs about 32 people per square mile. Among counties sharing McDowell County's EPA zone, it outranks 34% of them by population. EPA's geology-based Region 3 groups McDowell County with 244 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

A Zone 3 county like McDowell County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like McDowell County testing above the action level often enough that skipping a test isn't the safe assumption.

If McDowell County tests above the action level

Mitigation cost doesn't depend on McDowell 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

McDowell County's test kit answers today; a Airthings radon monitor keeps answering for McDowell 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.