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

Bell County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Bell County sits at the 31st percentile nationally for radon potential — above 31 of every 100 rated counties.

Bell County by the numbers

Bell County, Texas is home to about 399,578 people across 1,053.836 square miles. That works out to roughly 379 people per square mile. By population, Bell County is the 70th largest of every county sharing its EPA zone — the 93rd percentile by population within that zone. Bell County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Bell County

Bell 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. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Bell County testing above the action level often enough that skipping a test isn't the safe assumption.

If Bell County tests above the action level

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

Where Bell County's figures come from

Bell County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Bell County carries, the zone explainer covers what it does and doesn't tell you about any one house.