Is Harrison County, KY a radon risk area?

EPA's own radon map rates Harrison County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Nationally, Harrison County ranks higher in radon potential than 81% of rated counties (the 81st percentile).

How Harrison County compares

About 19,525 people live in Harrison County, Kentucky, spread over 306.458 square miles. That works out to roughly 64 people per square mile. Rank 583 by population within its EPA zone puts Harrison County at the 45th percentile among zone peers. EPA's geology-based Region 4 groups Harrison County with 735 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Harrison County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. Being in Zone 1 raises the odds Harrison 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 Harrison County

Nothing about Harrison 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 Kentucky's state radon program

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

More on how this number was built

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