What EPA's radon map says about Kerr County

EPA places Kerr 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. Rank it against the rest of the country and Kerr County lands in the 23rd percentile for radon potential.

Where Kerr County sits nationally

About 53,900 people live in Kerr County, Texas, spread over 1,103.333 square miles. That works out to roughly 49 people per square mile. Among counties sharing Kerr County's EPA zone, it outranks 69% of them by population. EPA's geology-based Region 6 groups Kerr County with 502 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Kerr County

At Zone 3, Kerr County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Even at Zone 3, Kerr County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in Kerr County

Mitigation cost doesn't depend on Kerr 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

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

Kerr 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.