Protecting Wells From Flooding

If your well is in a flood-prone area, be sure to protect it from floodwaters.

Here are some steps to take if you think your well is in danger of being inundated with floodwaters:

• Store a supply of drinking and household water before taking your well out of service.
• Turn off the electrical power to your well and seal the well by installing a watertight cap or cover. This watertight seal replaces the regular vented cap for the duration of the flood event. You also can cover the top of the well with one or two heavy-duty trash bags or other heavy plastic sheeting. Secure the plastic covering with electrical or strapping tape or some other type of waterproof taping material. Don’t use duct tape because it is not waterproof. If the well is in a small well house, wrap the outside with heavy-duty plastic and seal it next to the ground with boards, soil or bricks.
• Try to move any stored oil, gasoline, solvents, animal wastes and chemicals such as pesticides and fertilizers that are near the well to higher ground to reduce the chance of these becoming contaminants in the floodwaters and entering your well.
• Place freestanding fuel tanks where floodwaters will not affect them, or anchor the tanks to keep them from moving with the floodwaters. Identify large tanks with your name and address so they can be returned if they become displaced. Store drums and smaller containers in a fenced area, cabinet or storeroom.
• Determine if underground tanks are engineered to keep them from floating out of the ground if the contents are lighter than water.

Once floodwaters have receded, you need to determine if water reached the well casing. If it did, you should assume that the well was inundated and take measures to make sure your well is safe.

The first step is to determine if sediment or mud got into the well. If it did, contact a water well contractor to clean out the well.

Next, you will need to disinfect your well. Typically, this involves chlorinating to kill harmful bacteria or other contaminants. You can do this yourself. For more information on this process see Cleaning Flooded Wells.

Alternatively, you can have a water well contractor perform the cleaning and disinfection. For a list of licensed water well contractors in North Dakota, go to http://www.bwwc.nd.gov/index.html.

After the well is disinfected, you will need to have the water tested for coliform bacteria. For more information on testing see Drinking Water Quality: Testing and Interpreting Your Results.