Abstract
The seasonal variation in surface water quality of district Bageshwar, Uttarakhand (India) has been evaluated for 3 years from 2010 to 2012 for determining the suitability of water for drinking and irrigation needs. Water samples collected from different drinking water sources during pre-monsoon and post-monsoon seasons in each year were analysed for 23 water quality parameters including physico-chemical and metal analyses. The analysed water quality parameters show seasonal variation and low concentration in post-monsoon season compared to pre-monsoon season due to dilution effects. The Box and Whisker plots indicated the dominance of major cations and anions in order of Ca2+ > Mg2+ > Na+ > K+ and HCO3- > SO42- > Cl- in both seasons, respectively. Piper trilinear diagram showed that most of the water samples fall in Ca-Mg-HCO3 hydrogeochemical facies. The water quality index revealed deteriorated water quality at some of the sources during pre- and post-monsoon seasons. The Wilcox diagram and calculated sodium adsorption ratio, residual sodium carbonate and sodium percent values indicate that the water was suitable for irrigation purposes in both the seasons. The results concluded that water quality at some of the locations is deteriorating and needs proper monitoring to preserve and maintain its quality to reduce hazards to local population.