Is Lyon County, NV a radon risk area?

EPA's own radon map rates Lyon County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Nationally that's the 92nd percentile for radon potential — Lyon County outranks 92% of every county EPA has rated.

Where Lyon County sits nationally

About 63,718 people live in Lyon County, Nevada, spread over 2,003.054 square miles. Averaged across its land area, Lyon County runs about 32 people per square mile. Rank 263 by population within its EPA zone puts Lyon County at the 75th percentile among zone peers. Geologically, Lyon County is grouped into EPA Region 9 alongside 94 other counties that share its rock and soil setting.

What this actually means for a house in Lyon County

Lyon County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Lyon County specifically.

Next steps for a home in Lyon County

Nothing about Lyon County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Nevada's state radon program

Lyon County's test kit answers today; a Airthings radon monitor keeps answering for Lyon County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

More on how this number was built

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