What EPA's radon map says about Erath County

EPA places Erath 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. Nationally that's the 21st percentile for radon potential — Erath County outranks 21% of every county EPA has rated.

Where Erath County sits nationally

About 44,496 people live in Erath County, Texas, spread over 1,083.179 square miles. Population density there runs about 41 people per square mile. Among counties sharing Erath County's EPA zone, it outranks 64% of them by population. Geologically, Erath 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 Erath County

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Erath County's Zone 3 prediction is the low end of the scale. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Erath County testing above the action level often enough that skipping a test isn't the safe assumption.

Next steps for a home in Erath County

Mitigation cost doesn't depend on Erath 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

Erath County's test kit answers today; a Airthings radon monitor keeps answering for Erath 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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.