Is Columbia County, FL a radon risk area?

Columbia County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Columbia County in the 58th percentile nationally for radon potential — higher than 58% of the counties EPA has rated.

Columbia County by the numbers

About 73,977 people live in Columbia County, Florida, spread over 797.377 square miles. Population density there runs about 93 people per square mile. Rank 249 by population within its EPA zone puts Columbia County at the 76th percentile among zone peers. EPA's geology-based Region 4 groups Columbia County with 735 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Columbia County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. Middle-of-the-pack doesn't mean risk-free for any one Columbia County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Columbia County

Nothing about Columbia 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 Florida's state radon program

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

Columbia County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.