Bacteriological assessment of river Jataganga, located in Indian Himalaya, with reference to physico-chemical and seasonal variations under anthropogenic pressure: a case study

Bacteriological water quality of the river Jataganga, located in Indian Himalaya, has been assessed along with the physico-chemical and seasonal variations under anthropogenic activities, in two consecutive years. While the bacteriological analysis included total viable counts (TVC), total coliforms (TC), fecal coliforms (FC) and fecal streptococci (FS), the physicochemical factors included pH, temperature, conductivity, total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD) and chemical oxygen demand (COD). The TVC and TC were estimated to be highest in rainy season and lowest in winter at the sampling points, in both the years. FC fluctuated with respect to the location, season and year. FS also developed higher population in rainy season in both the years. The pure bacterial isolates belonged to the families Enterobacteriaceae, Micrococcaceae, Pseudomonadaceae and Bacillaceae, representing the indicators of water pollution, pathogens responsible for water borne diseases, and plant growth promoters as well. The pH and temperature of water at the sampling sites were about neutral to slightly alkaline and in psychrophilic range, respectively. The TDS was found to be within the minimum prescribed limits at all the study sites. The DO and BOD were assessed to be highest in winter followed by rainy and summer seasons, respectively, while COD was higher in rainy season followed by summer and winter, in both the years. Factorial analysis amongst years, locations and seasons, and their interaction with respect to the bacterial populations and the physico-chemical factors was statistically significant.