Assessment of Water Quality of Kosi River, Almora, Uttarakhand (India) for Drinking and Irrigation Purposes

Abstract

In the present study, seasonal variation in hydrochemical characters of Kosi River water has been evaluated and assessed the suitability of water for human consumption and irrigation purposes. Water samples were collected during pre-monsoon (PRM) and post-monsoon (POM) seasons of the years 2010 and 2011 and analysed for various physico-chemical, metals and bacteriological parameters according to national drinking water standard of India i.e. BIS:10500. Kosi River raw water and its supply water (water after treatment for domestic) were analysed. The dominance of major cations was in order of Ca2+>Mg2+>Na+>K+ and anions in order of HCO3−> Cl-> SO42− in water. No metal contamination was observed in water except, iron which exceeded the desirable and permissible limits. Total and fecal coliform counts were high in raw water than supply water. Piper diagram indicates that the water samples fall in Ca-Mg-HCO3− hydrochemical facies. Water quality index quantified for raw water was very high and found as unsuitable in PRM seasons of the entire monitoring period, compared to POM season and not found suitable for human consumption. The water quality index calculated for supply water showed good water quality. The study concluded that Kosi River water cannot be used for drinking purpose and accurate monitoring and pollution control measures are needed for improvement of the water quality. Calculated values of sodium adsorption ratio, sodium percentage and residual free chlorine indicated that Kosi River water is fit for irrigation purposes.