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

EPA places Rains 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. Rains County sits at the 9th percentile nationally for radon potential — above 9 of every 100 rated counties.

How Rains County compares

Rains County, Texas is home to about 13,306 people across 229.492 square miles. That works out to roughly 58 people per square mile. By population, Rains County is the 746th largest of every county sharing its EPA zone — the 28th percentile by population within that zone. Geologically, Rains County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Zone vs. an actual test

Rains 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. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Rains County testing above the action level often enough that skipping a test isn't the safe assumption.

Testing and mitigation in Rains County

For a Rains 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 Rains County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Rains 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 Rains County's figures come from

Rains 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.