Radioactive materials, also called radionuclides, come from geologic sources and are human-made. When radionuclides break down, they create radiation. Small amounts of radiation are common in the air, soil, surface water and groundwater. Different doses of radiation cause different health effects. Drinking water that has radionuclides puts you in contact with radiation every day. You have a higher risk of getting cancer if you drink water with radionuclides in it every day for many years.
This information is also available on the 
Minnesota Department of Health's Radionuclides (Radium) in Drinking Water.
Water testing
There are two options available for testing two radionuclides, radium and gross alpha, in your drinking water. Private wells are not required to be tested for radionuclides when newly constructed or at the time of property transfer.
See a map of radium levels in Dakota County wells
Dakota County
Pre-order a water test by emailing Dakota County at dcwatertestrequest@co.dakota.mn.us. Provide your name and address. County staff will schedule an appointment during normal business hours to come to your home or business to collect the water sample. Then you will ship the three, 1-liter sample bottles to the accredited laboratory in Tennessee. Expedited shipping is not required.
Cost: Residents pay the county $193 for radium test and $77 for gross alpha test
Results are expected in 20 business days.
Wisconsin State Lab
Request a test kit by calling the Wisconsin State Lab at 608-224-6203 or go to the Wisconsin State Lab website. You will need to collect and ship a gallon-size water sample. Expedited shipping is required. Sample must arrive at lab within five days.
Cost: Residents pays $278 for radium test and $78 for gross alpha test.
Results may take as long as two months.
Your water treatment devices may help
You may already have a water treatment device reducing radionuclides. A properly maintained reverse osmosis system will reduce gross alpha and radium. A properly maintained ion exchange device, like a water softener, can also reduce radium. Additional water treatment options for radium are listed on page 3 of the MDH Home Water Treatment Fact Sheet.
If you are concerned about ingesting radionuclides and are not using a water treatment device to reduce them, you may choose to test your water or install treatment. If you are considering water treatment, please refer to the Home Water Treatment Fact Sheet. You can find a licensed and registered water conditioning professional using the MDH License Lookup.
If you are unsure if your primary drinking water tap is softened, request a hardness test strip to be mailed to you by calling 952-891-7000 or pick one up at the Inver Glen Library.
Radon air testing
According to the MDH, there is no relationship between radionuclides in water and indoor radon levels. All homes should be tested for airborne radon, especially in the basement level because radon levels above the EPA action level of 4.0 pCi/L exist in households in the County. Information on how you can pick up a radon test kit can be found on the county's radon web page.