Clay County, TX: EPA's radon zone, explained

Clay County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally that's the 7th percentile for radon potential — Clay County outranks 7% of every county EPA has rated.

Clay County by the numbers

Clay County, Texas is home to about 10,730 people across 1,088.76 square miles. Population density there runs about 10 people per square mile. By population, Clay County is the 805th largest of every county sharing its EPA zone — the 22nd percentile by population within that zone. EPA's geology-based Region 6 groups Clay County with 502 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Clay 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 rating means Clay County's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

Testing and mitigation in Clay County

For a Clay County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Texas's state radon program

For Clay County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Clay County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Clay County's figures come from

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