Definition:

>Coliform bacteria are a collection of relatively harmless microorganisms that live in large numbers in the intestines of man and warm- and cold-blooded animals. They aid in the digestion of food. A specific subgroup of this collection is the fecal coliform bacteria, the most common member being Escherichia coli. These organisms may be separated from the total coliform group by their ability to grow at elevated temperatures and are associated only with the fecal material of warm-blooded animals.

>Coliform bacteria are a natural part of the microbiology of the intestinal tract of warm blooded mammals, including man. CQliform bacteria can also be found in soil, other animals, insects, etc. The total coliform group is relatively easy to culture in the lab, and therefore, has been selected as the primary indicator bacteria for the presence of disease causing organisms.

>Coliform bacteria:are naturally occurring, rod-shaped organisms which are widely distributed in nature. They exist in soil, on skin, in rivers, lakes and streams One type of coliform— FECAL COLIFORM — lives in the intestinal tract of man and animals. Coliforms are easily detected and their presence or absence has been used extensively in determining water quality

Total Coliform (Monthly): The presence of coliform bacteria in drinking water is generally a result of a problem with water treatment or the pipes which distribute the water, and possible contamination by disease-causing microorganisms (although the coliform themselves are not harmful) Disease symptoms may include diarrhea, cramps, nausea, and possibly jaundice, and any associated headaches and fatigue.

Coliform bacteria are not pathogenic (disease causing) organisms, and are only mildly infectious. For this reason these bacteria are relatively safe to work with in the laboratory. If large numbers of coliforms are found in water, there is a high probability that other pathogenic bacteria or organisms, such as Ecoli, may be present

Total Coliform (Acute): Fecal coliforms or E. Coli, are a particular type of coliform bacteria. Their presence in drinking water is more serious than other coliform bacteria because they are disease-causing, and also indicate that drinking water has been contaminated by sewage or animal wastes that contain other disease causing microorganisms. This type of contamination can cause severe diarrhea, cramps, and nausea. Because fecal coliform contamination is more severe than contamination by other types of coliform bacteria, EPA sets an acute standard indicating that for water to be considered safe it must be free of all fecal coliform.

TREATMENT:

Bacteria are removed by disinfection and/or filtration. Filtration alone may not be completely effective, but can improve the performance of disinfectants by removing

sediment that can shelter the bacteria. Methods of adding chlorine to water include solution feeders for dry chlorine or liquid chlorine or by feeding gas chlorine directly from 100,150, or 2000 lb. cylinders. Gas chlorination is recommended only for larger systems that can support the services of a trained water treatment plant operator. Chlorine is normally dosed to a concentration sufficient to maintain a free residual of at least 0.2 parts per million (PPM).

Other disinfectants include iodine. ozone, ultraviolet light. and physical methods such as boiling or steam sterilization. Chlorination is still the most common disinfection method in the United States, although recent concerns have been raised about the reaction of chlorine with organic matter in water. Such a reaction can result in the formation of trihalomethanes, which are suspect carcinogenic compounds. For most individual water supply systems, the most common form of treatment is ultraviolet disinfection.

FAQ’s

How do coliform bacteria get into my well? Wells may become contaminated through missing or defective well caps, defective seals around wires or pipes, inadequate or cracked well casing — or in any way surface water can enter into the well. Some well caps have a considerable gap between the rim of the cap and the casing, allowing insects and other vermin to enter and contaminate the well.

If I have bacteria in my water can it make me sick? Coliform bacteria are “indicator” organisms and are not generally harmful themselves. Because some are found in the intestines of warm-blooded animals, their presence may indicate that other, more harmful organisms may be present. Water which has these bacteria in it, then, should not be considered safe for drinking until treated.

What can I do if I have coliform bacteria in my well?

First of all, disinfect your well. Most drilled wells with adequate casing can be disinfected. If, after repeated chlorinations, there is still bacteria, a treatment device such as an Ultraviolet (UV) Light, Chlorinator or Ozonator may have to be installed. If fecal coliforms (E.coli) are present, a new well may have to be drilled.

How often should I have my water tested? Well water should be tested at least annually for bacteria and nitrates. Bacteria should be tested for whenever there is a change in the taste, color or odor of the water. Springs and shallow wells should be monitored more frequently.