After a flooding event or when your well has tested positive for total coliform bacteria, the well should be disinfected prior to use for drinking or food preparation. 

To disinfect a well:

• Use 1 – 2 gallons of bleach.
• Remove the plug from the top of your well (the plugs are usually plastic, round or square in shape, and are sometimes white, yellow or blue).  Make sure you keep this plug to re-seal your well afterward.
• Pour the gallon of bleach directly down the well itself.  Using a funnel sometimes makes this easier, depending on the size of the opening.  Re-plug the opening afterward.
• If you do not have a plug on your well head, it is recommended that you install one.  An open hole at the top of the well provides direct access for animals and bacteria to enter your well, which could allow future contamination.
• Make sure you by-pass any treatment systems, such as filters, water softeners, permanganate systems, etc.  Bleach will eat away at the filtration devices within these systems and they will have to be replaced.  Contact the manufacturer of the system if you cannot by-pass these tanks.
• Turn on the cold water faucets including sinks, showers, and hose spigots, both inside and outside the home and let the water run until you can smell bleach.  Turn off the water.
• Allow the water to sit in the pipes (unused) for 12 – 18 hours.  We do recommend the disinfection process be done overnight, when the water is unlikely to be used.
• Turn the cold water back, starting with the spigots outside, on after you’ve let it sit undisturbed.  Run the water to until you cannot smell the bleach anymore.

In addition to disinfect the well, if you have an aerator (the large tank of water) or a salt tank, we also recommend those be emptied and scrubbed with a solution of bleach and water. 

• Empty the tank of either water or salt.
• Mix 1 - 2 cups of bleach with a gallon of water in a plastic container.
• Using a brush, scrub the walls of the tank to clean any dirt or bacteria that may be growing.
• Rinse the tank with clean water thoroughly, especially a salt tank.  Again, you do not want bleach to end up inside the water softener as bleach will eat through the filtration mechanism.

Your water should be retested five to seven days after you’ve completed the disinfection process.  You may wish to drink or use bottled water for dishwashing, brushing teeth, etc. until your water is re-tested.

If you have any questions, please feel free to call 239.776.2630.

Sincerely,

Jaime Cook, M.S., R.S.

Environmental Supervisor II – Water Programs

The Florida Department of Health in Collier County

Environmental Health and Engineering