Bacterial indicators of faecal contamination of the Gangetic river system right at its source

Gangotri glacier is situated in the Uttaranchal, India between 30°56′N and 79°04′–79°15′ E. The Gangotri glacier around 30 km in length covering an area of 143 km2 flowing north–west, is the largest valley type glacier in the western Himalaya. Water samples from 21 different sites moving down stream from the glacier, which is the source of river Ganges, during winter, summer and monsoon seasons taken for the analysis of total viable count, total coliform count, faecal coliform count and faecal streptococci count, which are indicator organisms of faecal contamination. Total viable counts were found in the range of 2 × 102 to 40 × 102 ml−1 in winter, 7 × 102 to 40 × 102 ml−1 in summer and 2 × 102 to 40 × 102 ml−1 in monsoon. The range of MPN 100 ml−1 for total coliform was found 34–1600, 300–1600 and 40–1600, for faecal coliform, it was 2–500, 2–900, 2–900 and for faecal streptococci, it was 33–900, 40–900 and 40–1600 in winter, summer and monsoon, respectively. The overall objective of this work is to investigate the incidence of these indicator organisms, coliforms, faecal coliforms and faecal streptococci in runoff of the Gangotri glacier, western Himalaya, India.