Drinking water should be free from known pathogenic microorganisms and indicator bacteria which is a symptom for fecal
contamination of water. Coliforms are the most important indicator bacteria which are considered in the bacteriological examination of water[1]. Determination of coliform as an indicator of water contamination has been explained in 1011 standard (microbiological characteristics of water)
and the use of Escherichia coli (E. coli) and other coliform
bacteria and those coliforms that are indicator bacteria has
been recommended for the daily control of drinking water.
Coliform bacteria are used for monitoring the bacteriological
safety of water supplies on the basis of the realization that
the presence of coliform bacteria in water is an indicator
of potential human fecal contamination and therefore the
possible presence of enteric pathogens[2]