Pettis County, MO radon potential

EPA's own radon map rates Pettis County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. That puts Pettis County in the 54th percentile nationally for radon potential — higher than 54% of the counties EPA has rated.

Pettis County by the numbers

Pettis County, Missouri is home to about 43,791 people across 682.237 square miles. That works out to roughly 64 people per square mile. Within its own EPA zone, Pettis County is bigger by population than 64% of the counties that share it. EPA's geology-based Region 7 groups Pettis County with 411 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Pettis County

Pettis County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. A county-wide moderate average, like Pettis County's, can still hide a specific house well above or below it — testing is what actually answers the question.

If Pettis 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 Missouri's state radon program

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

Where Pettis 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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.