What EPA's radon map says about Dimmit County

EPA's own radon map rates Dimmit County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Dimmit County sits at the 5th percentile nationally for radon potential — above 5 of every 100 rated counties.

How Dimmit County compares

About 8,181 people live in Dimmit County, Texas, spread over 1,328.885 square miles. Averaged across its land area, Dimmit County runs about 6 people per square mile. Among counties sharing Dimmit County's EPA zone, it outranks 16% of them by population. EPA's geology-based Region 6 groups Dimmit County with 502 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Dimmit 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. Don't read Zone 3 as a pass for Dimmit County — EPA's guidance to test every home makes no exception for counties predicted low.

If Dimmit County tests above the action level

Mitigation cost doesn't depend on Dimmit 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

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

Dimmit 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.