What EPA's radon map says about Anderson County

Anderson County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Anderson County ranks higher in radon potential than 93% of rated counties (the 93rd percentile).

Anderson County by the numbers

About 81,449 people live in Anderson County, Tennessee, spread over 337.206 square miles. Population density there runs about 242 people per square mile. Among counties sharing Anderson County's EPA zone, it outranks 79% of them by population. Anderson 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 Anderson County

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Anderson County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Anderson County will test well under the action level, and EPA's guidance is to test regardless of zone.

Next steps for a home in Anderson County

Mitigation cost doesn't depend on Anderson County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Tennessee's state radon program

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

The methodology guide shows exactly which EPA and Census sources feed Anderson County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.