Is Hardeman County, TN a radon risk area?

EPA places Hardeman 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. That puts Hardeman County in the 16th percentile nationally for radon potential — higher than 16% of the counties EPA has rated.

Hardeman County by the numbers

About 25,434 people live in Hardeman County, Tennessee, spread over 667.768 square miles. That works out to roughly 38 people per square mile. Rank 540 by population within its EPA zone puts Hardeman County at the 48th percentile among zone peers. Geologically, Hardeman County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

What this actually means for a house in Hardeman County

A Zone 3 county like Hardeman County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 rating means Hardeman County's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

Next steps for a home in Hardeman County

Nothing about Hardeman County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Tennessee's state radon program

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

The methodology guide shows exactly which EPA and Census sources feed Hardeman County's numbers. Whatever zone Hardeman County carries, the zone explainer covers what it does and doesn't tell you about any one house.