Assessment of water quality of river Sutlej, Punjab (India)

Sutlej River is the longest river of Punjab, India, and a major source of water supply for irrigation, drinking, washing, and bathing in the region was studied through monthly surveys in two consecutive years (November, 2009–October, 2011). In Punjab region, river Sutlej receives a large amount of effluents from various industries and city sewage drains via “Budha Nallah and East Bein” which degraded the water quality of the river at different stretches. Keeping in view these point pollution sources, four collection sites (S₁–S₄) were selected to assess the Sutlej River. Additionally, groundwater sites (G₁–G₈) were selected in the 2 km surrounding to S₁–S₄ to check impact on groundwater. Fifteen physicochemical parameters were studied, which provide an idea for the portability of water for irrigation and drinking purposes as per permissible limits of WHO, ICMR, and ISI standards. Pearson correlation revealed a significant positive relationship between COD and BOD with chloride, total hardness, nitrate, phosphate and negative correlation with DO and water current. The mean values of water quality index (WQI) at sites S₁–S₄ were 20.79, 160.37, 36.31, and 104.70, respectively, which clearly indicated very high pollution load at S₂ and S₄. WQI at different groundwater sites (10.67 at G₁, 8.93 at G₂, 89.35 at G₃, 62.15 at G₄, 23.55 at G₅, 21.95 at G₆, 59.48 at G₇ and 39.92 at G₈) showed pollution load to different levels. On the basis of Central Pollution Control Board (CPCB) guidelines, the water at sampling stations S₁, G₁ and G₂ could be categorized as ‘A–B’, water of station at S₃, G₆, G₅ and G₈ as ‘B–C’, water at station S₄ as ‘C–D’ and the water at station S₂, G₃, G₄ and G₇ as ‘D–E’. Agglomerative cluster analysis (CA) was performed for delineating and grouping the similar pollution causing areas, which produced the same results as WQI. The results indicated that these point pollution sources clearly deteriorated the water quality of river Sutlej at sites S₂ and S₄, which in turn affected the groundwater in the surrounding areas.