Is Marion County, GA a radon risk area?

Marion County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally, Marion County ranks higher in radon potential than 5% of rated counties (the 5th percentile).

Where Marion County sits nationally

About 7,635 people live in Marion County, Georgia, spread over 365.721 square miles. That works out to roughly 21 people per square mile. Rank 885 by population within its EPA zone puts Marion County at the 14th percentile among zone peers. EPA's geology-based Region 4 groups Marion County with 735 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

A Zone 3 county like Marion County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 label describes Marion County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Marion County tests above the action level

Nothing about Marion 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 Georgia's state radon program

Marion County's test kit answers today; a Airthings radon monitor keeps answering for Marion County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

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.