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

EPA places Lake County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Lake County sits at the 31st percentile nationally for radon potential — above 31 of every 100 rated counties.

Lake County by the numbers

Lake County, Florida is home to about 444,204 people across 954.01 square miles. That works out to roughly 466 people per square mile. By population, Lake County is the 59th largest of every county sharing its EPA zone — the 94th percentile by population within that zone. Lake County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Lake County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. A Zone 3 label describes Lake County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Lake County tests above the action level

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 Florida'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. Use code RADONZONE-10OFF at checkout for 10% off.

Where Lake County's figures come from

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