Warren County, KY radon potential

EPA's own radon map rates Warren County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Nationally, Warren County ranks higher in radon potential than 96% of rated counties (the 96th percentile).

Warren County by the numbers

Warren County, Kentucky is home to about 147,936 people across 541.744 square miles. Averaged across its land area, Warren County runs about 273 people per square mile. Within its own EPA zone, Warren County is bigger by population than 87% of the counties that share it. EPA's geology-based Region 4 groups Warren County with 735 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Warren County

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Warren County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Warren County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Warren County tests above the action level

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 Kentucky's state radon program

For Warren County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Warren 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 Warren 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. Whatever zone Warren County carries, the zone explainer covers what it does and doesn't tell you about any one house.