How to Treat a Well Contaminated with Total Coliform

Store bottled water for drinking and cooking. You cannot consume your well water during shock chlorination, which typically takes at least four days. Use only bottled water for drinking, cooking, brushing your teeth, washing produce and similar activities. You may use your well water for cleaning and bathing if you do not accidentally swallow any of that water.

Calculate the amount of water that requires treatment. Contact your well's driller for the well log. Your state or county department of health also may provide this information. Use the figures in the well log to calculate the volume of water in your well. If, for example, the well casing diameter is 4 inches, then the water volume per foot of water depth is 0.65 gallons. If the well is 50 feet deep, multiply 50 by 0.65, which equals 32.5. Round that figure up to 33, and add the number of gallons in your water heater. Round that total up to the nearest 50 gallons. The result is the total water volume.

Determine how much liquid laundry bleach is needed for the total water volume . Use 3 pints of bleach for each 100 gallons of water. Use a liquid laundry bleach product, but do not use a laundry detergent product that contains bleach.

Pour the total amount of liquid laundry bleach you need into a 5-gallon bucket. Add enough water to fill the bucket.

Turn the well pump off, and remove the well cap. Removing the well cap provides access to the well.

Pour the contents of the bucket into the well slowly. Turn on the well pump, but leave the well cap off.

Connect a hose to an outdoor faucet. Turn on the faucet, and let its water run until you smell chlorine from the water it expels.

Rinse the well cap and all other hardware you see inside the well thoroughly with water from the hose. Turn off the faucet to which the hose is attached, and replace the well cap.

Turn on all indoor faucets one by one, and let each faucet run until you smell chlorine from its water. Turn on cold and hot water faucets individually. Turn off a faucet as soon as you detect chlorine in its water.

Wait 12 to 24 hours to allow the chlorine to work inside your home's water system.

Place the nozzle of the outdoor hose on an area of ground without vegetation. Run the outdoor faucet's water until you no longer smell chlorine. Turn off the outdoor faucet, and repeat this procedure for all indoor faucets.

Wait at least 72 hours. Do not use the well water for drinking during that time. After 72 hours, retest your water for total coliform bacteria. If your well water still tests positive for total coliform, then the well has an ongoing problem. A water treatment professional can discuss other options with you, such as digging a new well or installing a disinfection system.