Fayette County, OH radon potential

Fayette County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. That puts Fayette County in the 85th percentile nationally for radon potential — higher than 85% of the counties EPA has rated.

Fayette County by the numbers

Fayette County, Ohio is home to about 28,782 people across 406.361 square miles. Averaged across its land area, Fayette County runs about 71 people per square mile. Within its own EPA zone, Fayette County is bigger by population than 55% of the counties that share it. EPA's geology-based Region 5 groups Fayette County with 523 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.

Next steps for a home in Fayette County

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Ohio's state radon program

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

Where Fayette County's figures come from

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.