Bacterial indices of drinking water from natural sources

Two hundred forty samples of water from twenty natural sources were subjected to the study for the detection of four bacterial indicators of faecal pollution. The samples were subjected to the detection of coliform, faecal coliform, E. coli, S. faecalis, Cl. welchii and plate count at 37 degrees C and 22 degrees C. All these samples were found unfit for human consumption. MPN for coliforms, E. coli and S. faecalis varied from 3 to 1800 per 100 ml of water, sero to 1800 per 100 ml water and zero to 540 per 100 ml of water respectively. Plate count at 37 degrees C and 22 degrees C varied from 2.5 x 10(3) to > 150 x 10(3) per ml of water. Cl. welchii was detected in 30.4% samples in rainy season and high plate count at 37 degrees C and 22 degrees C was observed during the same period.