Well disinfection can eliminate or reduce many kinds of harmful bacteria and viruses as well as non-harmful bacteria that can cause unpleasant tastes and odors. Disinfection will not correct water problems caused by chemical contamination from nitrate, fuels, pesticides or other substances. Well disinfection should be performed:
- After the well is constructed
- When coliform bacteria are present in the water
- After plumbing installation (softeners, sinks, filters)
- After casing or pump repairs
- When drinking water tastes or odors change
- After flooding of the well
Refer to the Minnesota Department of Health's recommended procedure for 
disinfecting wells.