What EPA's radon map says about San Augustine County

EPA's own radon map rates San Augustine County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Nationally, San Augustine County ranks higher in radon potential than 5% of rated counties (the 5th percentile).

How San Augustine County compares

About 7,767 people live in San Augustine County, Texas, spread over 530.659 square miles. That works out to roughly 15 people per square mile. Among counties sharing San Augustine County's EPA zone, it outranks 14% of them by population. San Augustine 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

San Augustine 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 label describes San Augustine 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 San Augustine County

Mitigation cost doesn't depend on San Augustine 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

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