Is Butler County, MO a radon risk area?

Butler County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Butler County sits at the 20th percentile nationally for radon potential — above 20 of every 100 rated counties.

Where Butler County sits nationally

About 41,814 people live in Butler County, Missouri, spread over 694.754 square miles. Averaged across its land area, Butler County runs about 60 people per square mile. Rank 394 by population within its EPA zone puts Butler County at the 62nd percentile among zone peers. Geologically, Butler County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Zone vs. an actual test

A Zone 3 county like Butler County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Even at Zone 3, Butler 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 Butler County

Nothing about Butler 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 Missouri's state radon program

Butler County's test kit answers today; a Airthings radon monitor keeps answering for Butler 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 Butler County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.