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

Oldham County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. Nationally that's the 34th percentile for radon potential — Oldham County outranks 34% of every county EPA has rated.

Where Oldham County sits nationally

Oldham County, Texas is home to about 1,823 people across 1,500.523 square miles. That works out to roughly 1 people per square mile. By population, Oldham County is the 1009th largest of every county sharing its EPA zone — the 2nd percentile by population within that zone. Oldham County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Oldham County's Zone 2 prediction lands in the gap between the two. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Oldham County — testing is the only way to know an individual home's actual level.

Next steps for a home in Oldham County

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

Where Oldham County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Oldham County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.