What EPA's radon map says about Denton County

EPA places Denton County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Rank it against the rest of the country and Denton County lands in the 32nd percentile for radon potential.

Where Denton County sits nationally

About 1,045,120 people live in Denton County, Texas, spread over 878.762 square miles. That works out to roughly 1,189 people per square mile. Among counties sharing Denton County's EPA zone, it outranks 98% of them by population. Denton County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Denton County

At Zone 3, Denton County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Denton County testing above the action level often enough that skipping a test isn't the safe assumption.

Testing and mitigation in Denton County

Mitigation cost doesn't depend on Denton 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

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Denton County carries, the zone explainer covers what it does and doesn't tell you about any one house.