Is Addison County, VT a radon risk area?

Addison 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. Rank it against the rest of the country and Addison County lands in the 53rd percentile for radon potential.

Addison County by the numbers

About 38,047 people live in Addison County, Vermont, spread over 766.332 square miles. Population density there runs about 50 people per square mile. Rank 413 by population within its EPA zone puts Addison County at the 60th percentile among zone peers. EPA's geology-based Region 1 groups Addison County with 58 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Addison County

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Addison County's Zone 2 prediction lands in the gap between the two. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Addison County — testing is the only way to know an individual home's actual level.

Next steps for a home in Addison County

Nothing about Addison 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 Vermont's state radon program

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

More on how this number was built

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