DNR: Heavy flooding could result in contaminated wells

Wausau Pilot & Review

The Wisconsin Department of Natural Resources (DNR) encourages private well owners to consider testing their drinking water after significant rainfall and flooding.

Heavy rains, such as those that swept through much of northern Wisconsin the past week, can impact drinking water quality.

Flood waters and runoff contain bacteria and other contaminants that can affect private water supplies and cause the spread of waterborne illness. Wells located in pits, basements and low-lying areas are especially susceptible to contamination.

Well owners who experience flooding or observe changes to the taste, color or sediment levels in their water following heavy rainfall should assume their well is contaminated and take the following steps:

• Stop drinking the water and find an alternate source of safe water.
• Disinfect your well. This procedure is best done by a licensed well driller or pump installer with the expertise and equipment.
• Before resuming water consumption, sample the well after pumping and disinfection to ensure its safety.

Even without obvious signs of flooding, a well can become contaminated. The DNR’s Recommendations for Private Wells Inundated by Flooding webpage provides information on how to test and disinfect a private well after a flood event.

Private well owners are encouraged to test their wells annually for bacteria and nitrates to ensure the water is safe to drink. The DNR’s Wells webpage provides more information on bacteriological contamination of drinking water wells and lists of licensed well drillers, pump installers and labs certified to analyze water samples.

For individuals who receive their drinking water from a public water supply, these systems are designed and operated to keep contaminants out. If you have concerns about the safety of your community’s drinking water, contact your public water supplier.

For those impacted by the recent severe weather, the DNR’s Coping with Flooding webpage provides information on how to keep your family safe and minimize property damage during a flood. The Wisconsin Department of Health Services also provides information and links to resources on its Flood Hazards and Recovery webpage.