Lake County, TN: EPA's radon zone, explained

EPA's own radon map rates Lake County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Nationally that's the 4th percentile for radon potential — Lake County outranks 4% of every county EPA has rated.

How Lake County compares

Lake County, Tennessee is home to about 6,422 people across 165.785 square miles. Population density there runs about 39 people per square mile. By population, Lake County is the 914th largest of every county sharing its EPA zone — the 11th percentile by population within that zone. EPA's geology-based Region 4 groups Lake County with 735 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

At Zone 3, Lake County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. A Zone 3 rating means Lake County's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

Next steps for a home in Lake County

For a Lake 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 Lake County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Lake County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

Where Lake 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. Whatever zone Lake County carries, the zone explainer covers what it does and doesn't tell you about any one house.