Is Douglas County, MN a radon risk area?

EPA places Douglas 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, Douglas County ranks higher in radon potential than 88% of rated counties (the 88th percentile).

Where Douglas County sits nationally

About 39,933 people live in Douglas County, Minnesota, spread over 636.882 square miles. Population density there runs about 63 people per square mile. Rank 380 by population within its EPA zone puts Douglas County at the 64th percentile among zone peers. Geologically, Douglas County is grouped into EPA Region 5 alongside 523 other counties that share its rock and soil setting.

Zone vs. an actual test

Where the national indoor average runs about 1.3 pCi/L, Douglas County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. That doesn't mean every Douglas County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

If Douglas County tests above the action level

Nothing about Douglas 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

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

Douglas County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Douglas County carries, the zone explainer covers what it does and doesn't tell you about any one house.