What EPA's radon map says about McLennan County

EPA's own radon map rates McLennan 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 McLennan County lands in the 30th percentile for radon potential.

How McLennan County compares

About 270,358 people live in McLennan County, Texas, spread over 1,036.706 square miles. Population density there runs about 261 people per square mile. Among counties sharing McLennan County's EPA zone, it outranks 91% of them by population. Geologically, McLennan County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Zone vs. an actual test

McLennan County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. A Zone 3 rating means McLennan County's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

Next steps for a home in McLennan County

Mitigation cost doesn't depend on McLennan 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

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone McLennan County carries, the zone explainer covers what it does and doesn't tell you about any one house.