Cole County, MO: EPA's radon zone, explained

Cole County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Cole County in the 58th percentile nationally for radon potential — higher than 58% of the counties EPA has rated.

How Cole County compares

Cole County, Missouri is home to about 77,625 people across 391.533 square miles. Population density there runs about 198 people per square mile. By population, Cole County is the 246th largest of every county sharing its EPA zone — the 76th percentile by population within that zone. Geologically, Cole County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Cole County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). Nothing about a Zone 2 label lowers the case for testing in Cole County — EPA recommends it in every zone, moderate included.

Testing and mitigation in Cole County

For a Cole County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Missouri's state radon program

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

Where Cole 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 Cole County carries, the zone explainer covers what it does and doesn't tell you about any one house.