Greene County, AR: EPA's radon zone, explained

EPA's own radon map rates Greene County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Rank it against the rest of the country and Greene County lands in the 21st percentile for radon potential.

Greene County by the numbers

Greene County, Arkansas is home to about 46,928 people across 577.347 square miles. Averaged across its land area, Greene County runs about 81 people per square mile. By population, Greene County is the 360th largest of every county sharing its EPA zone — the 65th percentile by population within that zone. Geologically, Greene County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Zone vs. an actual test

Greene 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. Even at Zone 3, Greene County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

If Greene County tests above the action level

For a Greene 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 Arkansas's state radon program

For Greene County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Greene 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 Greene County's figures come from

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