Ripley County, MO radon potential

EPA's own radon map rates Ripley County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally that's the 40th percentile for radon potential — Ripley County outranks 40% of every county EPA has rated.

How Ripley County compares

Ripley County, Missouri is home to about 10,715 people across 629.516 square miles. That works out to roughly 17 people per square mile. Within its own EPA zone, Ripley County is bigger by population than 22% of the counties that share it. Ripley County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Ripley County

EPA's Zone 2 rating for Ripley County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. A county-wide moderate average, like Ripley County's, can still hide a specific house well above or below it — testing is what actually answers the question.

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

Where Ripley County's figures come from

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