Edgecombe County Environmental Health

How To Disinfect Your Well

Here are guidelines on how to disinfect your well. If you need help, call your county health department, a plumber or a well driller.

Well Disinfection

To disinfect your home water system, you must completely spread chlorine throughout the well and plumbing system. First, pump your well for about 30 minutes at the wellhead or an outside faucet to remove the most contaminated water. Then pour the following amount of non-scented household bleach (5.25% available chlorine) into the well according to the chart below:

Diameter Or Size Of Well Casing
Depth of Well	2 in.	4 in.	6 in.	20 in.	24 in.	30 in.	36 in.
10 ft deep	6 tsp bleach	½ cup bleach	1 cup Bleach	12 cups bleach	1 gallon + 2 cups bleach	1 ½ gallons bleach	2 gallons + 4 cups bleach
50 ft deep	½ cup bleach	4 cups bleach	½ gallon bleach	4 gallons bleach	6 gallons bleach	7 ½ gallons bleach	11 gallons bleach
100 ft deep	2 cups bleach	½ gallon bleach	12 cups bleach	8 gallons bleach	11 ½ gallons bleach	15 ½ gallons bleach	22 gallons bleach

Rinse the well casing and any other equipment inside the well with the chlorine. Turn on all the water faucets in the home until you smell a strong chlorine odor. Turn the faucets off and let the chorine stand in the well and plumbing system for at least 24 hours. Connect the garden hose to an outside faucet, and run water away from house foundation and septic tank system until the chlorine smell is gone. Do not pump the highly chlorinated water into a septic system.
After the disinfecting process has been completed, contact your local health department to have the water sampled. Continue using bottled water or water that has been at a rolling boil for 3 minutes until sampling shows no contamination.

CAUTION: Boiling water concentrates levels of nitrates in water. Young infants and pregnant women should use bottled water instead of boiled tap water for drinking and cooking.

Questions? Call your county health department.