If you have received a positive test for bacteria review these helpful publications.

• What to do if Coliform Bacteria is Present in a Well Water Sample

• How to Disinfect a Well and Water System - shock chlorination instructions

Use these web sites to find out more about bacteria in well water.

• Coliform Bacteria Fact Sheet from Oregon Health Division (pdf, see below)

• Bacteria in Drinking Water, University of Missouri. Very thorough: Includes info on testing, temporary disinfection, shock chlorination, water treatment systems, and using water for livestock.

• Bacteria and Well Water, American Groundwater Trust.

Check out these useful chlorination formulas

• Disinfectant solution for cleaning surfaces such as holding tank walls

• Shock chlorinating large volumes of water in a tank

• Disinfecting large volumes of water for emergency drinking water use.

If you need to disinfect drinking water temporarily, such as after a flood or any time bacteria is found in your water, read about using chlorine bleach or boiling to make your water safe.

Emergency Disinfection of Drinking Water, U.S. Environmental Protection Agency.