Coleman County, TX: EPA's radon zone, explained

Coleman County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally, Coleman County ranks higher in radon potential than 5% of rated counties (the 5th percentile).

How Coleman County compares

Coleman County, Texas is home to about 7,990 people across 1,262.974 square miles. That works out to roughly 6 people per square mile. By population, Coleman County is the 878th largest of every county sharing its EPA zone — the 15th percentile by population within that zone. Geologically, Coleman County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Coleman County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Even at Zone 3, Coleman County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in Coleman County

For a Coleman 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 Texas's state radon program

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

Where Coleman 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.