Minnesota's average indoor radon level is 4 pCi/L — more than three times the national average. If you own a home in Duluth, testing is not optional peace of mind. It is basic maintenance.
Radon is a colorless, odorless radioactive gas that seeps up out of the ground and collects inside buildings. It is the leading cause of lung cancer among people who have never smoked, and the second leading cause overall. You cannot smell it, taste it, or see it, and the only way to know what your house is doing is to measure it.
Minnesota has one of the worst radon problems in the country. According to the Minnesota Department of Health, two out of every five Minnesota homes tested come back with radon levels considered a major health risk, and roughly 72% of Minnesota counties fall into the highest average category. The statewide average indoor level is about 4 pCi/L. The national average is 1.3.
Duluth has its own reasons to be careful. The city sits on the Duluth Complex — hard gabbro and basalt bedrock with a thin, rocky layer of glacial soil over the top of it. Fractured bedrock close to the surface is an efficient pathway for soil gas to travel. Add the way this city is built, with thousands of homes cut into a steep hillside on walkout, daylight, and partially buried foundations, and you get an enormous amount of contact between living space and rock. Then add a heating season that runs most of the year. The result is a housing stock that is very good at pulling soil gas indoors.
The good news: radon is one of the few serious home problems with a permanent, affordable, well-understood fix. A properly designed mitigation system typically drops a home from a high reading to under 2 pCi/L, installs in a single day, and costs less than a decent furnace. Call (218) 520-9679 for a free estimate.
We handle the full range of radon work in Duluth — from a first measurement through system design, installation, and the confirmation test that proves the system actually worked.
Sub-slab depressurization, drain tile suction, and sealed sump systems that vent soil gas above the roofline and keep it out of the house.
Short-term and long-term measurement so you know what your house is actually doing before you spend a dollar on a system.
Fast-turnaround testing that fits inside an inspection window, plus the documentation the Minnesota Radon Awareness Act requires at closing.
Sub-membrane depressurization for the dirt-floor and partial crawl spaces that are common in older Duluth housing.
Schools, daycares, offices, and apartment buildings, where slab area, zoning, and HVAC interaction all change the design.
Every install is followed by a confirmation test. A system that has not been verified with a measurement is just a fan on a pipe.
Radon comes from the natural decay of uranium in rock and soil. It is present nearly everywhere in trace amounts. The problem is not that it exists — it is that buildings concentrate it.
Your house operates at slightly lower air pressure than the ground underneath it. Warm air rises and leaks out through the upper floors, attic bypasses, and roof penetrations, and that escaping air has to be replaced by air drawn in lower down. A good portion of that replacement air is pulled directly out of the soil through whatever openings exist in the foundation. This is the stack effect, and it is strongest when the temperature difference between inside and outside is greatest — which in Duluth means October through April.
Once you understand the mechanism, the common entry points are obvious:
A mitigation system does not seal all of these openings one by one. It does something smarter: it reverses the pressure. By running a fan on a pipe that reaches under the slab, the system makes the area beneath your foundation lower pressure than your basement. Soil gas takes the path of least resistance, which is now the pipe, not the crack. It gets carried up and discharged above the roofline where it disperses harmlessly.
Most residential systems in Minnesota land between $1,500 and $3,000 installed. That is a wide range because houses vary a lot, and the honest answer to "what will mine cost" requires someone to look at your foundation. These are the factors that actually move the number:
| Factor | Lower cost | Higher cost |
|---|---|---|
| Foundation type | Single poured slab basement | Block walls, multiple slabs, additions, partial crawl |
| Suction points needed | One point serves the whole slab | Two or more points for poor sub-slab communication |
| Existing drain tile | Interior loop with a sump to tie into | No drain tile; must core the slab and excavate a pit |
| Routing | Interior chase through a closet to the attic | Exterior run up the side of the house, sealed and painted |
| Sub-slab material | Clean gravel under the slab | Compacted clay or fill that resists airflow |
| Crawl space | None | Sub-membrane sheeting over exposed soil |
| Fan sizing | Standard residential inline fan | High-suction fan for tight soils |
An electrical permit is required for the fan circuit, and a confirmation test after the system is running should always be included. If a quote does not mention a post-installation test, ask why. Installing a system without measuring the result afterward means nobody — including you — knows whether it worked.
Minnesota requires a license. Anyone performing radon testing or mitigation in a building they do not own or lease must be licensed by the Minnesota Department of Health. National industry certification alone is not sufficient here. Ask for the MDH license number before any work begins — on any quote, from anyone, including us.
The Minnesota Radon Awareness Act applies to every residential sale in the state. Before a purchase agreement is signed, the seller has to provide the buyer with a written disclosure covering whether the home has been tested, any test results or reports in their possession, any mitigation work that has been performed, a Radon Warning Statement, and a copy of the MDH publication Radon in Real Estate Transactions.
What the law does not do is require a test. That stays negotiable between buyer and seller — which in practice means the buyer asks, and the deal timeline gets tight. A short-term test needs a minimum 48-hour closed-house period, and results have to come back before the inspection contingency expires. If you are working a transaction, our real estate radon testing page covers timing, closed-house conditions, and how mitigation typically gets negotiated at the table.
For sellers there is a straightforward argument for testing before you list: a documented mitigation system is a selling point, while a surprise 9 pCi/L result during the inspection window is a price negotiation you did not plan for.
We cover Duluth and the surrounding communities, including Lakeside, Lester Park, Congdon Park, Hunters Park, Woodland, Kenwood, Duluth Heights, Piedmont Heights, Central and East Hillside, Lincoln Park, West Duluth, Norton Park, Riverside, Morgan Park, Gary–New Duluth, Fond du Lac, and Bayview Heights — plus Hermantown, Proctor, Rice Lake, Duluth Township, Two Harbors, Esko, and Cloquet.
Most residential radon mitigation systems in Minnesota run $1,500 to $3,000 installed. In Duluth the final number depends on your foundation type, whether the system can be routed through the interior of the house or has to run up an exterior wall, how many suction points the slab needs, and whether an existing sump pit and drain tile can be used. Homes with a single poured slab and a usable drain tile loop sit at the low end. Older hillside homes with block foundations, additions, or partial crawl spaces sit higher.
No. The Minnesota Radon Awareness Act requires disclosure, not testing. Before a purchase agreement is signed, the seller must give the buyer a written statement covering whether the home has been tested, any test results and reports they have, any mitigation work that has been done, a Radon Warning Statement, and a copy of the Minnesota Department of Health publication Radon in Real Estate Transactions. Whether a test actually happens is negotiated between buyer and seller, and in practice most Duluth buyers ask for one.
The EPA action level is 4.0 pCi/L, and the EPA recommends that homeowners consider mitigation between 2.0 and 4.0 pCi/L as well. There is no level of radon considered completely safe, because the risk is cumulative over years of exposure. Minnesota's statewide average indoor level is about 4 pCi/L, which means a typical Minnesota home already sits at the threshold where the EPA says you should act.
Most single-family installations are finished in four to six hours in a single visit. Crawl space systems that require sub-membrane sheeting take longer, often a full day, because the soil has to be covered and sealed before the suction point goes in. After the fan is running you wait at least 24 hours before a confirmation test, and that test typically runs 48 hours.
Yes. Minnesota law requires anyone performing radon testing or mitigation in a building they do not own or lease to be licensed by the Minnesota Department of Health. National industry certification by itself is not sufficient in Minnesota. Ask for the MDH license number before work starts, and confirm that the finished system carries a permanent label with the installer's information on it.
Heated air rises and escapes through the upper part of the house, which lowers the pressure at the foundation and pulls soil gas in through cracks, block walls, and the sump pit. This is called the stack effect, and Duluth's long heating season keeps it running for much of the year. The same house can test at 2 pCi/L in July and 7 pCi/L in January, which is why testing during the heating season gives you the more useful number. Our radon testing page covers seasonal timing in more detail.
Barely. A radon fan draws roughly the same power as a standard light bulb and runs continuously, which typically works out to a few dollars a month. A properly designed system pulls soil gas from beneath the slab rather than conditioned air out of the living space, so it should not meaningfully change your heating load. A system that noticeably increases heating costs is usually a sign of poor sealing at the suction point.
A test takes 48 hours and settles the question. If the number comes back high, we will tell you exactly what a system for your foundation would cost — no obligation.