Harmful bacteria can invade a home well at any time. Though the levels of bacteria in wells are not usually high enough to cause harm, this is not always the case. If you find your drinking water is overly polluted and unsafe to drink, you may need to cleanse your water system thoroughly to get rid of the bacteria. Using common household bleach is an excellent way to do this. When used correctly, it is a safe and quick method for cleaning wells and water systems.
Consult your local water board to determine how much bleach to put into your water system safely. As a general rule, wells that are 2 to 4 inches in diameter usually require a cup of bleach. If you are unsure of your well's diameter or if the diameter is larger, consult a professional before attempting to add bleach.
Open your well cap. How you do this will vary and depend on the type of well you have. If you see no pipes sticking out of the well cap, then you can unbolt it and remove the cap. If you do see pipes, you will probably need to consult a professional for opening instructions because removing bolts from this type of well could result in losing the cap and/or water pump down your well if you do not know what you are doing.
Dilute the bleach in a 2-gallon bucket of water, and pour the solution down the well. Using only bleach can cause metal parts to corrode.
Turn all outdoor and indoor faucets and let them run until you can smell chlorine.
Stop using the water when you smell the chlorine. Let the chlorine sit in the water pipes for at least 10 hours.
Run all faucets until you no longer smell chlorine.
Test your water after about three days to make sure your cleaning was successful and all bacteria was eliminated. Water test kits are available at your local hardware or home improvement stores.