Is Carlton County, MN a radon risk area?

EPA's own radon map rates Carlton County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. That puts Carlton County in the 52nd percentile nationally for radon potential — higher than 52% of the counties EPA has rated.

How Carlton County compares

About 36,745 people live in Carlton County, Minnesota, spread over 861.195 square miles. That works out to roughly 43 people per square mile. Rank 426 by population within its EPA zone puts Carlton County at the 59th percentile among zone peers. Carlton County falls in EPA Radon Region 5, one of 524 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Carlton County

EPA's Zone 2 rating for Carlton County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Carlton County's Zone 2 rating sits in the middle nationally; EPA's guidance is unchanged by that — test every home regardless of its zone.

Next steps for a home in Carlton County

Nothing about Carlton 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 Minnesota's state radon program

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

Carlton County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.