Is Sumner County, TN a radon risk area?

Sumner County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. Rank it against the rest of the country and Sumner County lands in the 62nd percentile for radon potential.

Sumner County by the numbers

About 211,721 people live in Sumner County, Tennessee, spread over 529.453 square miles. Population density there runs about 400 people per square mile. Rank 115 by population within its EPA zone puts Sumner County at the 89th percentile among zone peers. Geologically, Sumner 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 Sumner County

Call it a middle case: above the 1.3 pCi/L most US homes average, below the 4 pCi/L line EPA uses to recommend mitigation — that's Sumner County's Zone 2 prediction. A county-wide moderate average, like Sumner County's, can still hide a specific house well above or below it — testing is what actually answers the question.

Next steps for a home in Sumner County

Nothing about Sumner 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

Sumner County's test kit answers today; a Airthings radon monitor keeps answering for Sumner County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.