Runoff puts drinking water at risk
MADISON, Wis. — Warming temperatures, snow melt, residual frozen ground and rain can create conditions that may affect private wells and drinking water.
"Our recent round of snow, rain and mixed precipitation throughout the state serves as a reminder that changing spring weather can lead to well contamination," said Marty Nessman, Wisconsin Department of Natural Resources private water supply field supervisor. "At this time of year we encourage well owners to watch for signs of flooding and note any change in the color, smell or taste of their drinking water."
Owners who see flood waters very near or over their wells should assume their water could be contaminated. Take the following steps:
• Stop drinking the water and find another safe source.
• Once the waters recede, make sure the well is properly disinfected.
• Before drinking the water again, sample the well to assure the water is safe.
Flood waters and rain runoff may contain bacteria and other contaminants that can affect water supplies and cause illness. Wells located in pits, basements and low-lying areas are especially susceptible to contamination.
Nessman said disinfection and sampling is best done by a licensed well driller or pump installer. Any water supply system that has been submerged by flood waters should be pumped out once the floodwater recedes, then thoroughly disinfected and tested to determine that the water is safe.
To ensure safe drinking water, well owners are encouraged to learn whether they have a properly constructed well and test it annually for bacteria. More information on bacteriological contamination of drinking water wells, along with lists of licensed well drillers, pump installers and labs certified to analyze water samples can be found by searching the DNR website, dnr.wi.gov for wells.
For individuals who receive drinking water from a public water supply, these systems are designed and operated to keep out contaminants. If you have concerns about the safety of your community's drinking water, contact your public water supplier.