What EPA's radon map says about Tom Green County

Tom Green County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally, Tom Green County ranks higher in radon potential than 27% of rated counties (the 27th percentile).

How Tom Green County compares

About 120,103 people live in Tom Green County, Texas, spread over 1,522.32 square miles. That works out to roughly 79 people per square mile. Among counties sharing Tom Green County's EPA zone, it outranks 81% of them by population. Geologically, Tom Green County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Zone vs. an actual test

A Zone 3 county like Tom Green County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Tom Green County testing above the action level often enough that skipping a test isn't the safe assumption.

If Tom Green County tests above the action level

Mitigation cost doesn't depend on Tom Green 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 Texas's state radon program

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

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Tom Green County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.