Physicochemical and microbiological assessment of spring water in central Himalayan region

In the present study, water quality of 16 springs, located along National Highway-58 from Rishikesh to Badrinath in India, was assessed by determining various physicochemical and microbiological parameters in three different seasons, i.e., pre-monsoon, monsoon, and post-monsoon. For majority of the springs, the pH was slightly alkaline with temperature ranging between 10 and 27 °C. All other parameters such as total hardness (TH), total alkalinity (TA), chloride, phosphate, nitrate, total dissolved solids (TDS), electrical conductivity (EC), dissolved oxygen (DO), and biochemical oxygen demand (BOD) were found to lie within the acceptable limit prescribed by various standard national and international agencies. The principal component analysis reveals that water quality of springs mainly depends on mineral contents of water, as there is a loading of TH, TA, EC, TDS, and other mineral components during one or other season of a year. The positive correlation coefficients determined among mineral components of spring water further substantiate this fact. No loading of DO, BOD, nitrate, and phosphate indicates an absence of anthropogenic pollution in the studied area. No trace metals were detected in any of the springs. Most probable number (MPN) index for coliforms was found to be above the acceptable limit for all the springs in one or more seasons of a year, except the one in Pandukeshwar. Plate-based assay revealed the presence of pathogens like Salmonella, Shigella, Vibrio, and Pseudomonas in some spring water. The findings of the present work reveal that due to high MPN index and presence of other pathogenic bacteria, water from most of the springs cannot be considered completely safe for direct human consumption in its raw form.