What EPA's radon map says about Fayette County

EPA's own radon map rates Fayette County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Nationally that's the 98th percentile for radon potential — Fayette County outranks 98% of every county EPA has rated.

Where Fayette County sits nationally

About 329,437 people live in Fayette County, Kentucky, spread over 283.854 square miles. Averaged across its land area, Fayette County runs about 1,161 people per square mile. Among counties sharing Fayette County's EPA zone, it outranks 93% of them by population. EPA's geology-based Region 4 groups Fayette County with 735 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Fayette County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. Being in Zone 1 raises the odds Fayette County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Testing and mitigation in Fayette County

Mitigation cost doesn't depend on Fayette County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Kentucky's state radon program

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

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