If you are a private well owener, and a natural disaster has occurred on or near your property, there are some things you should know about your drinking water supply. During a flood of major proportions, bacteria has most likely infiltrated the well. At this point if you are planning to use your well for drinking and cooking purposes, steps toward disinfecting the well should begin.
Shock chlorination is the preferred method for eliminating bacterial contamination in wells.
For drill wells, you'll have to disassemble the top of the casing. For bored or dug wells, open the cover and then add the disinfectant. The chlorine solution must remain in the well for a 24-hour period, preferably overnight, before it is pumped out. In addition to disinfecting the well, you should also disinfect the plumbing system in the home and other buildings on your property which rely on the well water. To do this, turn on all water faucets after the chlorine is added to the well.