Calhoun County, AL: EPA's radon zone, explained

EPA's own radon map rates Calhoun County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Rank it against the rest of the country and Calhoun County lands in the 95th percentile for radon potential.

How Calhoun County compares

Calhoun County, Alabama is home to about 116,427 people across 605.894 square miles. That works out to roughly 192 people per square mile. By population, Calhoun County is the 167th largest of every county sharing its EPA zone — the 84th percentile by population within that zone. EPA's geology-based Region 4 groups Calhoun County with 735 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Calhoun County

Where the national indoor average runs about 1.3 pCi/L, Calhoun County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. That doesn't mean every Calhoun County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Next steps for a home in Calhoun County

For a Calhoun County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Alabama's state radon program

For Calhoun County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Calhoun County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

Where Calhoun County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.