Is Austin County, TX a radon risk area?

Austin County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Austin County sits at the 18th percentile nationally for radon potential — above 18 of every 100 rated counties.

Austin County by the numbers

About 32,546 people live in Austin County, Texas, spread over 646.514 square miles. Population density there runs about 50 people per square mile. Rank 461 by population within its EPA zone puts Austin County at the 55th percentile among zone peers. EPA's geology-based Region 6 groups Austin County with 502 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Austin County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. A Zone 3 rating means Austin 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.

Testing and mitigation in Austin County

Nothing about Austin County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Texas's state radon program

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

More on how this number was built

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