What is radon?
Radon is a radioactive gas that forms naturally when uranium in soil and rock breaks down. It has no color, smell or taste. It moves up through the ground and into homes through cracks and openings in the foundation.
Why is radon dangerous?
Breathing radon over time raises your risk of lung cancer. The EPA estimates radon causes about 21,000 lung cancer deaths in the US each year, and it's the leading cause of lung cancer among people who have never smoked.
What level is too high?
The EPA recommends fixing your home if radon is 4.0 pCi/L or higher, and considering a fix between 2 and 4. The average indoor level in the US is about 1.3 pCi/L.
How common is high radon in South Dakota?
Very common. American Lung Association data shows about six in ten South Dakota homes tested were above the EPA action level. Eastern South Dakota is in the EPA's Zone 1, the highest predicted category.
My neighbor's house tested low. Do I still need to test?
Yes. Radon levels can differ a lot between neighboring homes because of foundation type, soil and how the house is built and used.
Do new homes have radon?
They can. Radon comes from the soil, not the age of the house. Some new homes have a passive radon pipe; if the home tests high, a fan can often be added.
How does a mitigation system work?
Most systems use a fan and PVC pipe to pull radon from under the foundation and vent it above the roofline. The fan runs all the time and costs about $3 a month in electricity, according to the state.
How much does it cost?
South Dakota DANR estimates a typical installation at about $1,200. Finished basements, crawl spaces and mixed foundations can cost more. See our cost guide for details.
Is 605 Radon a contractor?
No. 605 Radon is a referral service. We connect you with an independent radon contractor who serves your area. They quote and do the work, and they may pay us for the referral. The referral is free to you.
Are the contractors certified?
We only refer to contractors certified by NRPP or NRSB, the two national radon certification programs South Dakota DANR recommends. Ask any contractor to show you their certification.
Can I get a free test kit?
South Dakota DANR offers a limited number of free test kits each year to residents. Passive kits are also inexpensive at hardware stores and online.
Can radon be in well water?
Yes. If you're on a private well, mention it when you request a quote. Treatment for radon in water is different from an air system.
Sources: EPA, Health Risk of Radon; South Dakota DANR, Radon; American Lung Association data, reported by Dakota News Now (2023).