What EPA's radon map says about Limestone County

EPA places Limestone 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 15th percentile for radon potential — Limestone County outranks 15% of every county EPA has rated.

How Limestone County compares

About 22,569 people live in Limestone County, Texas, spread over 905.43 square miles. That works out to roughly 25 people per square mile. Among counties sharing Limestone County's EPA zone, it outranks 45% of them by population. EPA's geology-based Region 6 groups Limestone County with 502 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

A Zone 3 county like Limestone County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Even at Zone 3, Limestone County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Next steps for a home in Limestone County

Mitigation cost doesn't depend on Limestone 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

Limestone County's test kit answers today; a Airthings radon monitor keeps answering for Limestone 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

Limestone County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Limestone County carries, the zone explainer covers what it does and doesn't tell you about any one house.