What EPA's radon map says about Brooks County

EPA's own radon map rates Brooks County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. That puts Brooks County in the 4th percentile nationally for radon potential — higher than 4% of the counties EPA has rated.

How Brooks County compares

About 6,740 people live in Brooks County, Texas, spread over 943.355 square miles. Population density there runs about 7 people per square mile. Among counties sharing Brooks County's EPA zone, it outranks 12% of them by population. EPA's geology-based Region 6 groups Brooks County with 502 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

A Zone 3 county like Brooks County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 rating means Brooks County's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

If Brooks County tests above the action level

Mitigation cost doesn't depend on Brooks 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

Brooks County's test kit answers today; a Airthings radon monitor keeps answering for Brooks 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

Brooks County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.