How to Disinfect a Well

Information from National Testing Laboratories.

To disinfect a private well . . .

1. Remove well cover. Pour the required amount of bleach into the well. See the list below.

2. Run ALL faucets in the house, one at a time, until you smell the chlorine at the faucet. This ensures that the whole system will be disinfected

3. Connect a garden hose to an outside tap or an indoor tap with the correct thread fitting. Put the other end of the hose into the well, turn on the faucet, and from time to time move the hose so that the chlorinated water bathes the sidewalls of the well casing. Do this for at least six hours. Turn off tap and remove the hose from the well.

4. Replace the well cover

5. DON’T USE THE WATER for at least twelve hours. Forty-eight hours in optimal.

6. Run the water to waste but NOT INTO THE SEPTIC SYSTEM for several hours, or until the chlorine taste is dilute enough to be unobjectionable. The best way to run the water to waste is to use the garden hose mentioned above (item 3). Direct the hose into an area where the chlorinated water will not cause environmental damage or affect the water supply of others. For a typical well, this may take 3-4 hours. NOTE: To avoid pump overheating and possible damage, turn off the water when flow is at a trickle and wait at least 15 minutes before turning on the pump again

7. After a week of use, retest for bacteria.

8. In some cases, one chlorination treatment WILL NOT be sufficient. Repeat disinfection procedures as needed.