Is Summit County, UT a radon risk area?

Summit 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. Nationally that's the 54th percentile for radon potential — Summit County outranks 54% of every county EPA has rated.

How Summit County compares

About 43,109 people live in Summit County, Utah, spread over 1,870.674 square miles. Averaged across its land area, Summit County runs about 23 people per square mile. Rank 382 by population within its EPA zone puts Summit County at the 63rd percentile among zone peers. Summit County falls in EPA Radon Region 8, one of 291 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Summit 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 Summit County — EPA recommends it in every zone, moderate included.

Next steps for a home in Summit County

Nothing about Summit 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 Utah's state radon program

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

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