What EPA's radon map says about Calhoun County

EPA's own radon map rates Calhoun County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Calhoun County sits at the 13th percentile nationally for radon potential — above 13 of every 100 rated counties.

How Calhoun County compares

About 19,942 people live in Calhoun County, Texas, spread over 506.936 square miles. That works out to roughly 39 people per square mile. Among counties sharing Calhoun County's EPA zone, it outranks 40% of them by population. Calhoun County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Calhoun 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 rating means Calhoun 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.

Next steps for a home in Calhoun County

Mitigation cost doesn't depend on Calhoun 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

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

The methodology guide shows exactly which EPA and Census sources feed Calhoun County's numbers. Whatever zone Calhoun County carries, the zone explainer covers what it does and doesn't tell you about any one house.