Well Disinfection Calculator

Based on Indiana Department of Health (IDOH) guidance for private wells after flooding.

Calculate chlorine disinfectant
Enter your well type and depth to estimate the amount of 5% chlorine bleach needed.

Use the total depth of the well.

What to do next
  1. Add the chlorine solution. Pour the diluted solution directly into the casing of a single tubular well, or into the annular space between the outer casing and the drop pipe of a double tubular well. If the well is sealed and the pump drop pipe has no foot valve or cylinder in the way, you may pour it down through the pump and drop pipe.
  2. Pump until chlorine is present throughout the system. Pump long enough to bring treated water to all faucets. If you do not smell chlorine, add slightly more bleach until a distinct odor is noticed.
  3. Let it stand. Leave the chlorinated well and distribution system unused for 12–24 hours.
  4. Flush the system. After at least 12 hours, pump to waste until no chlorine odor remains. If you have a septic system, first run water through a garden hose into a roadside ditch or drainage swale; then flush each faucet.
  5. Test before use. After disinfecting, sample the water for bacteriological analysis. Contact your local health department or a certified lab for a test kit.

Remember

Water cannot be considered safe based only on appearance, smell, or taste. Organisms that cause waterborne illness may not be detectable without laboratory testing.

Guidance provided by the Indiana Department of Health (IDOH). If your well was not submerged but you are concerned about water quality, testing is still recommended.

Visit IDOH