Radon testing
You can't guess a radon level. You have to measure it. Here's how testing works on both sides of the river.
Radon varies from house to house, even between neighbors built the same year. A test tells you whether you need a system, and a test after a system goes in tells you whether it's doing its job.
Which kind of test should I use?
| Test | Length | Good for |
|---|---|---|
| Short-term kit | A few days | A first look, or a quick check after a system is installed |
| Long-term kit | More than 90 days | Your average across a season, or most of a year |
| Continuous monitor | Usually 2 days or more, recorded hour by hour | Real estate deals and professional testing |
How do I set up a kit so the result is right?
- Place it on the lowest floor you live on, such as a finished basement, or the main floor if no one uses the basement.
- Keep windows and outside doors closed, apart from normal coming and going, for at least 12 hours before and during a short-term test.
- Set it at about breathing height, away from the sump, floor drains, exterior walls, kitchens, bathrooms and heat registers.
- Write down start and stop times and mail it to the lab right away; most labs reject kits that sit too long.
Is winter the right time to test here?
It's a good time. ND DEQ encourages testing during the cold-weather months, when houses stay closed up and the stack effect pulls the most soil gas inside. A winter result reflects how most Grand Forks households live for a large part of the year. A long-term test that runs through winter into spring gives you a fuller picture.
Where do I get a kit, and when do I need a pro?
North Dakota residents can request one of DEQ's limited free kits while supplies last, and kits are sold at hardware and building supply stores. A radon measurement professional brings a calibrated continuous monitor and handles placement, which matters for real estate and for post-mitigation tests. In Minnesota, someone who places or retrieves test devices in a building they don't own must hold an MDH radon measurement license, so ask for it in East Grand Forks and Crookston.
My result is over 4. What now?
If it was a short-term kit, a second test helps confirm the number before you spend money. If the level holds at 4 pCi/L or higher, MDH and the EPA recommend a mitigation system. Between 2 and 4, both suggest you consider one. See sub-slab radon systems.
Pricing comes from the radon company once it knows your foundation and has usually seen the house in person. We don't quote prices, and any figure given over the phone is a rough starting point, not a bid.
Where we connect you with help
Common questions
Does a new house need a radon test?
Yes. New homes can test high too. Minnesota has required radon-resistant construction in new homes since 2009, but MDH still recommends testing every home.
Should I test each floor?
Start with the lowest level you use. A radon professional may test more than one spot in a larger house or one with several foundation types.
Related services
More background: Red River Valley radon guide.
Radon kit came back over 4?
Call and a local radon mitigation company will look at your house and quote a system.