Rutherford County, TN: EPA's radon zone, explained
Rutherford County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Rank it against the rest of the country and Rutherford County lands in the 98th percentile for radon potential.
How Rutherford County compares
Rutherford County, Tennessee is home to about 376,996 people across 619.548 square miles. Population density there runs about 609 people per square mile. By population, Rutherford County is the 61st largest of every county sharing its EPA zone — the 94th percentile by population within that zone. EPA's geology-based Region 4 groups Rutherford County with 735 other counties nationally sharing its underlying rock and soil profile.
Why the zone isn't the answer by itself
Where the national indoor average runs about 1.3 pCi/L, Rutherford County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. Being in Zone 1 raises the odds Rutherford County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.
Next steps for a home in Rutherford County
For a Rutherford 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 Tennessee's state radon program
For Rutherford County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Rutherford 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 Rutherford 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. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.