Douglas County, WI: EPA's radon zone, explained

EPA's own radon map rates Douglas County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. That puts Douglas County in the 54th percentile nationally for radon potential — higher than 54% of the counties EPA has rated.

Where Douglas County sits nationally

Douglas County, Wisconsin is home to about 44,276 people across 1,304.272 square miles. That works out to roughly 34 people per square mile. By population, Douglas County is the 371st largest of every county sharing its EPA zone — the 64th percentile by population within that zone. Geologically, Douglas County is grouped into EPA Region 5 alongside 523 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

EPA's Zone 2 rating for Douglas County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. A county-wide moderate average, like Douglas County's, can still hide a specific house well above or below it — testing is what actually answers the question.

Next steps for a home in Douglas County

For a Douglas County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Wisconsin's state radon program

For Douglas County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Douglas County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Douglas County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.