Is Tarrant County, TX a radon risk area?

EPA's own radon map rates Tarrant County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. That puts Tarrant County in the 33rd percentile nationally for radon potential — higher than 33% of the counties EPA has rated.

Where Tarrant County sits nationally

About 2,230,708 people live in Tarrant County, Texas, spread over 865.4 square miles. Population density there runs about 2,578 people per square mile. Rank 9 by population within its EPA zone puts Tarrant County at the 99th percentile among zone peers. EPA's geology-based Region 6 groups Tarrant County with 502 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Tarrant 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. Don't read Zone 3 as a pass for Tarrant County — EPA's guidance to test every home makes no exception for counties predicted low.

Testing and mitigation in Tarrant County

Nothing about Tarrant 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

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

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