Is Chippewa County, MN a radon risk area?

EPA places Chippewa County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally that's the 77th percentile for radon potential — Chippewa County outranks 77% of every county EPA has rated.

How Chippewa County compares

About 12,299 people live in Chippewa County, Minnesota, spread over 581.225 square miles. That works out to roughly 21 people per square mile. Rank 715 by population within its EPA zone puts Chippewa County at the 33rd percentile among zone peers. EPA's geology-based Region 5 groups Chippewa County with 523 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Chippewa County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. 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 Chippewa County specifically.

Testing and mitigation in Chippewa County

Nothing about Chippewa 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

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

Chippewa County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.