Is Guadalupe County, TX a radon risk area?

EPA's own radon map rates Guadalupe County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Rank it against the rest of the country and Guadalupe County lands in the 29th percentile for radon potential.

Where Guadalupe County sits nationally

About 195,166 people live in Guadalupe County, Texas, spread over 711.252 square miles. Averaged across its land area, Guadalupe County runs about 274 people per square mile. Rank 135 by population within its EPA zone puts Guadalupe County at the 87th percentile among zone peers. Guadalupe County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Guadalupe County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. A Zone 3 label describes Guadalupe County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Next steps for a home in Guadalupe County

Nothing about Guadalupe 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

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

Guadalupe County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.