Photo: Johnny McClung on Unsplash.com

By Laura Durenberger-Grunow - Boreal Community Media - March 20, 2025


Last week was National Groundwater Awareness Week, and the State of Minnesota used the opportunity to remind residents who receive water from a private well to annually test for contaminants. 

According to the Minnesota Department of Health (MDH), 1.1 million residents statewide rely on private wells for their water source. “You can’t taste, smell or see most contaminants, so testing is the only way to know how safe your water is,” said MDH Water Policy Manager Tannie Eshenaur in a release. While consuming large quantities of contaminants isn't beneficial to anyone, it can be especially harmful to developing infants and children. 

The five most common contaminants found throughout the state, including in Cook County, are the following: 

• Coliform bacteria: a group of microorganisms that can indicate the presence of fecal contamination. This group of bacteria can cause gastrointestinal illnesses, including diarrhea, vomiting, and abdominal cramps. Coliform bacteria can enter well water sources through surface water infiltration, faulty septic systems, or animal waste.
  
  
• Nitrates: a common contaminant in groundwater that are especially harmful to infants. High nitrate levels can interfere with the blood's ability to carry oxygen, leading to a condition known as "blue baby syndrome." Nitrates can enter well water sources from the breakdown of organic matter and septic system leaks. 
  
  
• Arsenic: a naturally occurring element that can cause cancer of several organs, cardiovascular and respiratory disease, reduced intelligence in children, and skin problems such as lesions, discoloration, and corns. Can naturally enter well water sources through natural geological formations.
  
  
• Manganese: a naturally occurring element that, while necessary for human health in small quantities, excessive exposure can lead to problems with memory, attention, and motor skills. Can naturally enter well water sources through natural geological formations.
  
  
• Lead: a toxic metal that can contaminate groundwater, especially in older homes with lead plumbing built before 1978. Lead contamination can cause serious health problems, particularly in children, including developmental delays, learning disabilities, and behavioral problems.

The Minnesota Department of Health and Cook County Land Services recommend testing for coliform bacteria and nitrates once a year or anytime the water color, taste, or smell changes. 

Both departments also recommend testing for arsenic, manganese, and lead at least once or in an instance where an infant or child will be consuming the water. 

Since December 2024, the Cook County Land Services Department has begun offering free well water test kits, thanks to a grant from the Minnesota Department of Health. Residents who are year-long owners or long-term renters can pick up a free kit with sampling instructions at the Land Services office in the Cook County Courthouse. Priority is given to seniors 65+, families with young children and infants, veterans, the Grand Portage Band of Lake Superior Chippewa, recipients of the Healthy Homes program, and people with disabilities. Additionally, those who qualify for Medical Assistance, WIC, MN Family Investment Program, Energy Assistance Program, Reduced or Free School Lunch, Head Start, and/or SNAP. Learn more or inquire here.

If a resident does not fall under any of those categories, the MDH has other well-testing options and resources, which can be found on its website here.

The Land Services Department will notify residents who obtain a free kit through Cook County if contaminants above the normal limit are detected in the test. Limited funding is available for treatment for income-based individuals or families.

Questions are welcome at Land Services by email to [email protected] or call 218-387-3678 

The Minnesota Department of Health also offers grants or loans for water treatment. Learn more here.