What EPA's radon map says about New Madrid County

EPA's own radon map rates New Madrid County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. New Madrid County sits at the 10th percentile nationally for radon potential — above 10 of every 100 rated counties.

How New Madrid County compares

About 15,212 people live in New Madrid County, Missouri, spread over 674.884 square miles. That works out to roughly 23 people per square mile. Among counties sharing New Madrid County's EPA zone, it outranks 32% of them by population. New Madrid 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 New Madrid County

New Madrid County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. Even at Zone 3, New Madrid County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Next steps for a home in New Madrid County

Mitigation cost doesn't depend on New Madrid County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Missouri's state radon program

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

More on how this number was built

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