Casey County, KY: EPA's radon zone, explained

EPA's own radon map rates Casey County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. That puts Casey County in the 79th percentile nationally for radon potential — higher than 79% of the counties EPA has rated.

How Casey County compares

Casey County, Kentucky is home to about 15,948 people across 444.258 square miles. Averaged across its land area, Casey County runs about 36 people per square mile. By population, Casey County is the 643rd largest of every county sharing its EPA zone — the 40th percentile by population within that zone. EPA's geology-based Region 4 groups Casey County with 735 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Casey County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. Some Casey County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

Testing and mitigation in Casey County

For a Casey 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 Kentucky's state radon program

For Casey County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Casey County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Casey County's figures come from

Casey 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.