What EPA's radon map says about Millard County

Millard County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Millard County in the 42nd percentile nationally for radon potential — higher than 42% of the counties EPA has rated.

How Millard County compares

About 13,572 people live in Millard County, Utah, spread over 6,785.482 square miles. That works out to roughly 2 people per square mile. Among counties sharing Millard County's EPA zone, it outranks 28% of them by population. Geologically, Millard County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

Zone vs. an actual test

Millard County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). Nothing about a Zone 2 label lowers the case for testing in Millard County — EPA recommends it in every zone, moderate included.

Next steps for a home in Millard County

Mitigation cost doesn't depend on Millard 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 Utah's state radon program

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

The methodology guide shows exactly which EPA and Census sources feed Millard County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.