Disinfecting Water

Drinking water should be free of coliform bacteria. The EPA drinking water standards indicate that water should contain less than one coliform organism in 100 milliliters. If your coliform test was reported as contaminated, take these steps:

Disinfect your well
Resample the well and have a second coliform test run.
If possible, locate and correct the source of bacteria contamination.

There are a number of ways of disinfecting water but remember, treatment of a water supply is a safety factor, not a corrective measure. Don't install a permanent means of disinfection unless you are sure the contamination originates from the groundwater and that it is not a temporary condition.

The use of chlorine is the oldest and most common disinfection method for private water supplies. Chlorine is inexpensive and readily available, reliable, easy to use and monitor, and effective against most pathogenic bacteria, virus and cyst organisms. It also kills non-pathogenic iron, manganese and sulfur bacteria.

Chlorine is also a strong oxidizing agent which causes a problem mineral such as soluble iron and manganese to change to an insoluble precipitate so it can be filtered from the water.

For use in the home, chlorine is readily available as sodium hypochlorite commonly known as household bleach. This product contains 5 percent available chlorine. Chlorine is also available as calcium hypochlorite, which is sold in the form of dry pellets. In this form it has about 70 percent available chlorine.

Chlorination may be done in many ways. Chlorine may be used continuously in the dry or liquid form that is dropped or injected into the well water using a chemical feed pump. For periodic or shock water treatment, chlorine can also be poured in or fed in solution using a hose.

Source: University of Georgia
Prepared by: Dale Dorman, Extension Housing Specialist
http://www.engr.uga.edu/service/extension/publications/c819-10c.html