With the risk of flooding increasing in many parts of the state, Minnesota health officials urge private well users to prepare for the possibility their wells might flood. Taking preventive action now may save well users more trouble down the road.
Wells contaminated with floodwater pose a health risk, but the impact floodwaters have on wells and water quality are often not as visible as other flood damage. With that in mind, the Minnesota Department of Health (MDH) offers well users the following recommendations:
• If your well is in a flood-prone area and you have time, consider contacting a licensed well contractor to check your well and make any necessary repairs or changes to help protect it from flooding. These changes may include repairing cracked or damaged casing, extending the well casing above the expected flood level or temporarily replacing the vented well cap with a watertight cap or cover. You should also make sure that grading allows water to flow away from your well.
• If you think your well might become flooded, store a supply of clean water that will last for at least a few days. Shut off power to the well pump to avoid having floodwater pumped into your plumbing system or home. If you only have a little time before a flood, you can cover the well with a heavy plastic bag or sheeting and secure it with electrical tape. This won’t completely protect your well from contamination, but it will help reduce the amount of water and debris that could enter your well, making clean-up easier.
• If floodwater reaches your well, assume your well is contaminated.
Water from a contaminated well should not be used for drinking, cooking or brushing your teeth until the floodwater recedes and the following steps have been completed:
• Avoid electrical shock. Do not approach a flooded well until it has been completely disconnected from its power source.
• If floodwater covered your well or may have entered your well directly, have a licensed well contractor inspect the well, clean out sediment or debris, and disinfect it. Using your well pump to remove sediment or debris could ruin the pump.
• If floodwater reached your well but you are confident that floodwater did not enter the well, have a licensed well contractor disinfect your well or complete the disinfection yourself. After the well has been disinfected, contact your county health department or a laboratory accredited by MDH to get your well tested. Tell them you need to have your well water tested for coliform bacteria.
If your well water test comes back positive for coliform bacteria, repeat the disinfection and testing process. You may need to disinfect and test your well several times.
Learn more on the MDH Web site at www.health.state.mn.us.