Is Marquette County, WI a radon risk area?

EPA's own radon map rates Marquette County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. That puts Marquette County in the 44th percentile nationally for radon potential — higher than 44% of the counties EPA has rated.

How Marquette County compares

About 15,743 people live in Marquette County, Wisconsin, spread over 455.706 square miles. Population density there runs about 35 people per square mile. Rank 699 by population within its EPA zone puts Marquette County at the 32nd percentile among zone peers. Marquette County falls in EPA Radon Region 5, one of 524 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

EPA's Zone 2 rating for Marquette County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Middle-of-the-pack doesn't mean risk-free for any one Marquette County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Marquette County

Nothing about Marquette 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 Wisconsin's state radon program

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.