Drinking Water and Other Waters Bacterial Testing (Fecal / Total Coliform)

  • The total and fecal coliform bacteria test is a primary indicator of “potability” , suitability for consumption,  of drinking water. It measures the concentration of total coliform bacteria associated with the possible presence of disease causing organisms.


  • Coliform bacteria are a natural part of the microbiology of the intestinal tract of warm blooded mammals, including man.  Coliform 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.

Health Hazards:

  • 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 Giardia and Cryptosporidium, may be present.   The PADEP requires public drinking water supplies to demonstrate the absence of total coliform per 100 mls (about 4 oz) of drinking water. At this time, there are no regulations governing individual water wells.  It is up to the private well owner to have his or her water tested.

Other facts:

  • BOD is a measure of oxygen removed from an aquatic environment by aerobic microorganisms. Turbidity is the measure of relative clarity of a liquid. It’s measured in nephelometric turbidity units (NTU). In ordinary river water, it’s usually less than 10 NTU. Bramhaputra has 290-400! Experts previously blamed it on the construction of dams and tunnels in China but now it’s revealed that earthquake and landslides in Tibet are responsible behind this mudding of water.

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