Is Rhea County, TN a radon risk area?

EPA places Rhea 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 that's the 19th percentile for radon potential — Rhea County outranks 19% of every county EPA has rated.

Where Rhea County sits nationally

About 34,759 people live in Rhea County, Tennessee, spread over 315.494 square miles. That works out to roughly 110 people per square mile. Rank 441 by population within its EPA zone puts Rhea County at the 57th percentile among zone peers. Rhea County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Rhea County

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Rhea County's Zone 3 prediction is the low end of the scale. A Zone 3 label describes Rhea County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Next steps for a home in Rhea County

Nothing about Rhea 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

Rhea County's test kit answers today; a Airthings radon monitor keeps answering for Rhea 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. Whatever zone Rhea County carries, the zone explainer covers what it does and doesn't tell you about any one house.