Radon Mitigation in Winona, MN

Winona sits in a high-radon corner of Minnesota

Winona County lies in the Driftless Area of southeastern Minnesota. The last glaciers missed this region, so instead of deep glacial till the ground here is thin soil over fractured limestone and sandstone bedrock. Uranium in that rock and soil breaks down into radon gas. The fractures and karst channels under the bluffs give the gas an easy path upward. It rises through slab cracks, floor drains, sump baskets, and unsealed foundation joints into the house above.

The river-valley climate makes it worse. A Winona winter keeps homes closed and heated for months. A warm, sealed house acts like a chimney and pulls soil gas inward through the lowest level. That is why radon readings climb in the heating season.

Winona's housing adds to the risk. Much of the city's housing stock, from the older neighborhoods near downtown to homes built out on the bluffs, went up long before Minnesota's 2009 code began requiring radon-resistant construction. Those houses were built with no radon protection at all. The only way to learn your number is to test. If it comes back at 4.0 pCi/L or higher, the EPA says fix it. More on local geology and state data is on our Winona County radon levels page.

How it works

• Tell us about your house. Foundation type, sump or no sump, finished or unfinished basement. It takes five minutes by phone or on the quote form.
• Get a firm quote from a licensed pro. The price does not grow later. Most Winona area homes land inside the MDH benchmark of $1,500 to $3,000. See the cost guide.
• One-day install by a licensed pro. The job covers the suction point, a sealed sump lid where needed, the fan, the vent stack, and the system gauge.
• Proof it worked. A follow-up test confirms your new level before the job is called done.

Radon questions Winona homeowners ask

How do I know if my Winona home has high radon?

Testing is the only way to know. Radon has no color, no smell, and no taste. Levels change from one house to the next, even between neighbors. The Minnesota Department of Health reports that about two in five Minnesota homes test above the EPA action level of 4.0 pCi/L.

What radon level is considered too high?

The EPA sets its action level at 4.0 pCi/L and recommends fixing any home at or above it. No level is fully safe. The EPA also suggests weighing mitigation between 2.0 and 4.0. Minnesota's statewide average is about 4.2 pCi/L, more than three times the national average of 1.3.

How much does radon mitigation cost in Winona?

Most standard sub-slab systems in Minnesota run $1,500 to $3,000 installed, per MDH. Foundation type, home age, fan placement, and electrical work move the number. See our cost guide for a full breakdown.

How long does installation take?

Most single-family homes are finished in one day. A follow-up test then confirms the new level.

My Winona home is newer. Am I already protected?

Maybe not. Minnesota code has required passive radon-resistant construction in new homes since 2009, but passive pipe alone does not always hold levels down. Test first. If the number is high, adding a fan to the existing passive stack is usually the cheapest fix available.

Who is allowed to do radon work in Minnesota?

Since January 1, 2019, Minnesota law requires anyone paid to test or mitigate radon to hold a license from the Minnesota Department of Health. Every new system must carry an MDH system tag. You can verify any license on the state's radon licensing site.