Is Hamilton County, TN a radon risk area?

EPA's own radon map rates Hamilton County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally, Hamilton County ranks higher in radon potential than 64% of rated counties (the 64th percentile).

Hamilton County by the numbers

About 386,256 people live in Hamilton County, Tennessee, spread over 542.165 square miles. Population density there runs about 712 people per square mile. Rank 65 by population within its EPA zone puts Hamilton County at the 94th percentile among zone peers. Geologically, Hamilton County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Zone vs. an actual test

EPA's Zone 2 rating for Hamilton County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. A county-wide moderate average, like Hamilton County's, can still hide a specific house well above or below it — testing is what actually answers the question.

If Hamilton County tests above the action level

Nothing about Hamilton 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

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

The methodology guide shows exactly which EPA and Census sources feed Hamilton County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.