Access to safe drinking water is a fundamental requirement for good health and is also a human right. The monitoring of water supplies for the detection of faecal pollution is an important aspect for the detection of pathogenic bacteria, responsible for diseases such as gastroenteritis, cholera and bacillary dysentery thus representing serious health hazards. Most drinking water suppliers rely on faecal indicators, such as the well-established Escherichia coli (E. coli) or the total coliform enumeration.
In the present study, the physico-chemical parameters (pH, turbidity and conductivity) and the enumeration of the micro-organisms, E. coli, total coliform and clostridium perfringens were carried out in raw, filtered and treated water samples over a period of five months (August–December 2014) at three different stations. Filtration of water caused a considerable decrease on turbidity (about 55%) except at Station 3, where the treated water was mixed with raw water coming from a borehole. After filtration and chlorination the water samples tested were found to be free from the indicator organisms (coliform organisms and presumptive E. coli).
However, the presence of clostridium perfringens were detected and enumerated in chlorinated water samples (0–3 CFU) for the samples collected during drought season. Therefore, treatment of water samples with chlorine can eliminate the coliform bacteria, but the more resistant pathogens are not eliminated completely Hence, clostridium perfringens could be used as an additional bio-indicator to assess faecal pollution and to monitor the treatment of drinking water more efficiently.
Key words- drinking water, E. coli, coliform organisms, clostridium perfringens