Is Robertson County, TX a radon risk area?

EPA places Robertson County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally that's the 12th percentile for radon potential — Robertson County outranks 12% of every county EPA has rated.

How Robertson County compares

About 17,659 people live in Robertson County, Texas, spread over 855.155 square miles. Averaged across its land area, Robertson County runs about 21 people per square mile. Rank 670 by population within its EPA zone puts Robertson County at the 35th percentile among zone peers. Geologically, Robertson County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

A Zone 3 county like Robertson County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 label describes Robertson County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Robertson County tests above the action level

Nothing about Robertson 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

Robertson County's test kit answers today; a Airthings radon monitor keeps answering for Robertson 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 Robertson County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.