Lamar County, TX radon potential

EPA's own radon map rates Lamar County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Rank it against the rest of the country and Lamar County lands in the 22nd percentile for radon potential.

Where Lamar County sits nationally

Lamar County, Texas is home to about 51,249 people across 907.335 square miles. That works out to roughly 56 people per square mile. Within its own EPA zone, Lamar County is bigger by population than 67% of the counties that share it. Lamar 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 Lamar County

Lamar County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. A Zone 3 label describes Lamar County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Lamar County tests above the action level

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Texas's state radon program

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

Where Lamar County's figures come from

Lamar County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.