Disinfection destroys nuisance and disease-causing bacteria and other microorganisms in drinking water. However, it is not a long-term substitute for a safe water supply. If living organisms have contaminated your private well or water
supply, proper disinfection kills them. However, it won't reduce nitrates or eliminate other contamination problems.

Water can be disinfected with heat, chemicals, or light. Boiling water, at a rolling boil, for 5 to 8 minutes kills bacteria and parasites like giardia and ryptosporidium. Boiling water concentrates nitrate levels. Therefore, don't boil if there's
nitrate in the water.

Water can also be disinfected with chlorine, bromine, iodine, or ozone. Chlorine also oxidizes iron and manganese so they can be filtered out. High concentrations of chlorine give water a bad taste. They may combine with other components to form cancer-causing compounds. Ozone may be used to disinfect public water supplies. It is rarely used for private water supplies.

Chlorine is used most often to disinfect private wells contaminated by disease-causing or nuisance bacteria. A well may be contaminated when it is flooded or when the watertight casing is no longer intact. It may be contaminated
when it is opened for maintenance or repair. Homeowners may chlorinate wells themselves, or they may hire professionals. If you hire professionals, make sure they are licensed contractors.

If you disinfect your well, calculate how much chlorine is need for your situation. It is important that the entire household plumbing system be disinfected. The chlorine must stay in piping long enough to kill all living organisms.

Extension has a publication that helps calculate how much chlorine to add to your system. It also explains more about how to disinfect your well. Call your local Extension office and ask for Treatment Systems for Household Water
Supplies: Chlorination, publication #5941.

Ultraviolet can disinfect water, although it has limitations. The water must be filtered. It must be free of iron or other compounds. They might interfere with the ultraviolet light's ability to penetrate the cell wall to kill the living organism.
Some countertop household water treatment systems use ultraviolet light.

Remember, continuing disinfection is no substitute for a permanent safe water supply. It helps reduce nuisance bacteria and odors. It also makes water safe until a sanitary supply is secured. If your well is contaminated, boil the water, carry water from a safe supply or buy bottled water until the problem is corrected.