Suitability of spring water from the Upper Beas River Basin in Kullu Valley (Western Himalaya, India) for drinking and irrigation purposes

Spring water is a reliable source of potable water to many communities and habitants in western Himalayan region of India. The present study evaluates the hydrochemical nature of spring water using various drinking parameters and agricultural indices in upper Beas basin of Kullu Valley, Himachal Pradesh, India. Fifty springs were sampled for the estimation of physico-chemical parameters and major ions. The results indicate that majority of the spring waters in the study area are suitable for drinking as well as irrigation purposes except for few locations. About 14% of springs showed high nitrate content (45 to 92.6 mg/L) more than BIS permissible limit of 45 mg/L. The source of contamination could be sewage disposal, livestock waste and fertilizers. Fluoride (0.16-0.49 mg/L) was found to be within permissible limits for drinking. Drinking Water Quality Index ranges from 1.74 to 108, and Irrigation Water Quality Index ranges from 0.27 to 8.21. Both these indices indicate that the spring water falls in excellent to good category and is suitable in terms of potability and irrigation uses. Hydrogeochemical characteristics of the spring waters indicate that alkaline earths (Ca2+ + Mg2+) dominate alkalies (Na+ + K+) and strong acids (SO42- + Cl-) dominate weak acids (CO32- + HCO3-). Based on Piper's classification, the spring water data falls in no cation-no anion dominant zone followed by carbonate hardness (secondary alkalinity) zone and hydrochemical trends (Piper's and Gibb's plots) inferred that spring water chemistry is mainly controlled by water rock interaction followed by rainwater chemistry.