What EPA's radon map says about Calloway County

EPA places Calloway County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Calloway County ranks higher in radon potential than 20% of rated counties (the 20th percentile).

Calloway County by the numbers

About 38,975 people live in Calloway County, Kentucky, spread over 384.863 square miles. Population density there runs about 101 people per square mile. Among counties sharing Calloway County's EPA zone, it outranks 60% of them by population. EPA's geology-based Region 4 groups Calloway County with 735 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Calloway County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. Even at Zone 3, Calloway County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Next steps for a home in Calloway County

Mitigation cost doesn't depend on Calloway 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 Kentucky's state radon program

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

Calloway 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.