Is Chatham County, GA a radon risk area?

Chatham County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Chatham County in the 30th percentile nationally for radon potential — higher than 30% of the counties EPA has rated.

How Chatham County compares

About 307,336 people live in Chatham County, Georgia, spread over 432.796 square miles. That works out to roughly 710 people per square mile. Rank 84 by population within its EPA zone puts Chatham County at the 92nd percentile among zone peers. Chatham County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

A Zone 3 county like Chatham 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 Chatham County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Chatham County tests above the action level

Nothing about Chatham 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

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

More on how this number was built

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