What EPA's radon map says about Graham County

Graham County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally that's the 68th percentile for radon potential — Graham County outranks 68% of every county EPA has rated.

Where Graham County sits nationally

About 2,370 people live in Graham County, Kansas, spread over 898.527 square miles. That works out to roughly 3 people per square mile. Among counties sharing Graham County's EPA zone, it outranks 5% of them by population. Geologically, Graham County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Graham County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. Some Graham 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 Graham County

Mitigation cost doesn't depend on Graham 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 Kansas's state radon program

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

Graham County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.