What EPA's radon map says about Hamilton County

Hamilton County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally, Hamilton County ranks higher in radon potential than 6% of rated counties (the 6th percentile).

Where Hamilton County sits nationally

About 8,644 people live in Hamilton County, Texas, spread over 835.915 square miles. Averaged across its land area, Hamilton County runs about 10 people per square mile. Among counties sharing Hamilton County's EPA zone, it outranks 17% of them by population. Geologically, Hamilton County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

What this actually means for a house in Hamilton County

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Hamilton County's Zone 3 prediction is the low end of the scale. Don't read Zone 3 as a pass for Hamilton County — EPA's guidance to test every home makes no exception for counties predicted low.

If Hamilton County tests above the action level

Mitigation cost doesn't depend on Hamilton 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

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