Determination of Bacterial contamination from Well water

Background: Water is one of the most basic needs of life. 90% of the groundwater accounts for the world’s freshwater resources, used for irrigation, industry, and human consumption. Well water is considered as the sole source of drinking water in many regions. The water should be checked regularly to determine bacterial contamination in order to prevent water born bacterial diseases. This study was performed to evaluate the microbial quality of the water from the wells used for drinking purpose. Method: In this cross-sectional study, twenty water samples from ten different wells around the agricultural area were collected in a 200ml capacity sterile container, transported to the laboratory and examined for presumptive coliforms by multiple fermentation tube test. The presumptive coliform count per 100 ml of water was determined using the probability table. Bacteria were then identified using conventional methods. Results: All samples were contaminated with bacteria, and the most predominant bacteria isolated were Klebsiella pneumoniae (40%), followed by Pseudomonas aeruginosa (26%) and E.coli (13%). Of the ten wells tested, seven well water samples were found to be excellent, one satisfactory and two were unsatisfactory. No pathogenic bacteria were seen in any of the samples. Conclusion: Before consumption of water, it should be adequately boiled, or filtered to prevent the incidence of water-borne diseases. Regular screening for bacterial contaminants is necessary in reducing the contamination and supplying safe drinking water.