Radon Guide for Grand Forks & East Grand Forks (2026)

Updated October 19, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	North Dakota (Grand Forks, Larimore)	Minnesota (East Grand Forks, Crookston)
How common	63% of homes above 4.0 pCi/L; EPA Zone 1 (ND DEQ)	More than 2 in 5 homes at significant risk; average over 3 times U.S. (MDH)
Action level	EPA 4 pCi/L	Mitigate at 4 pCi/L or more; consider 2 to 4 (MDH)
Who may install	Homeowner or contractor; DEQ lists contractors and explains NRPP certification	MDH-licensed mitigation professional and company for buildings you don't own (Minn. Stat. 144.4961)
System tag	Not described by DEQ	MDH tag on every professionally installed system
Home sales	Not described by DEQ	Seller disclosure under the Radon Awareness Act, since Jan. 1, 2014
New homes	Not described by DEQ	Radon-resistant construction required since 2009 (MDH)
Kits and help	Limited free kits from DEQ; DEQ radon coordinator 701-328-5166	MDH Indoor Air Unit 651-201-4601

How common is radon here?

Very. ND DEQ says 63 percent of North Dakota homes have radon above the EPA action level of 4.0 pCi/L and that the EPA classifies North Dakota as Zone 1, the highest potential for elevated radon. On the Minnesota side, MDH says more than two in five homes have radon at levels that pose a significant health risk and that the state's average is more than three times the national average. These are statewide figures. Your house can be higher or lower than your neighbor's, so test it.

Why does it matter?

The EPA estimates about 21,000 lung cancer deaths a year in the U.S. are caused by radon. It's the number one cause of lung cancer among non-smokers and the second leading cause overall. Smokers exposed to radon face a much higher combined risk.

How and when should I test?

ND DEQ and the EPA recommend testing homes, and DEQ specifically encourages testing during cold-weather months. Test the lowest floor you live on, with the house closed up. DEQ gives away a limited number of free kits to North Dakota residents, mailed while supplies last, and kits are sold at most hardware and building supply stores. MDH recommends testing every Minnesota home. In Minnesota, someone placing or retrieving test devices in a building they don't own must hold an MDH measurement license; testing your own home does not need one.

When should I fix it?

MDH recommends a mitigation system when the level is 4 pCi/L or higher and suggests considering one between 2 and 4 pCi/L, because no level is risk-free. The EPA's guidance is the same. ND DEQ says mitigation systems can reduce radon and that a properly installed system vents the gas safely outside. The common design is sub-slab depressurization for basements and slabs, and a sealed membrane with suction for crawl spaces.

Who can install a system in North Dakota?

ND DEQ says a mitigation system can be installed by a homeowner or by a radon mitigation contractor. DEQ publishes a list of contractors, notes that NRPP certification means a contractor has completed radon training and testing requirements, and states that inclusion on the list isn't an endorsement. DEQ's list includes several contractors based in Grand Forks. Ask any contractor for proof of certification, references and a written proposal.

Who can install a system in Minnesota?

Minnesota's radon licensing law, Minn. Stat. 144.4961, signed in May 2015, requires a license for anyone who installs or designs a mitigation system, or supervises mitigation on site, in a building they don't own or lease, and for the companies that employ them. Licensing is administered by MDH under Minnesota Rules chapter 4620. MDH says every professionally installed system must carry an MDH tag next to the pressure gauge, the work must follow ANSI/AARST protocols, and each installation comes with an operation, maintenance and monitoring plan for the owner. People working on a building they own or lease are exempt.

What do Minnesota sellers have to disclose?

Under the Minnesota Radon Awareness Act, Minn. Stat. 144.496, for purchase agreements signed on or after January 1, 2014, a seller must disclose in writing what they know about radon in the house, including tests, levels and any mitigation system, and give the buyer a radon warning statement and MDH's "Radon in Real Estate Transactions." MDH notes the act doesn't require a test or mitigation.

What about new houses?

MDH says all new Minnesota homes have been required to be built radon-resistant since 2009. That means sealed entry points, gravel and a soil-gas retarder under the slab, a passive vent pipe from below the foundation through the roof, and an attic junction box so a fan can be added. MDH still recommends testing, and a passive system can be upgraded to active with a fan.

Common questions

Does Minnesota require a license for radon mitigation?

Yes. MDH licenses radon mitigation professionals and companies, and every professionally installed system gets an MDH tag.

How common is radon in North Dakota?

ND DEQ says 63 percent of North Dakota homes test above the EPA action level of 4.0 pCi/L.

Where can I get a radon test kit in Grand Forks?

ND DEQ mails a limited number of free kits to residents while supplies last, and hardware and building supply stores sell them.

Red River Valley radon guide: North Dakota and Minnesota rules (2026)