Water Quality Assessment of Garmarood River Using the National Sanitation Foundation Water Quality Index (NSFWQI), River Pollution Index (RPI) and Weighted Arithmetic Water Quality Index (WAWQI)

Rivers are recognized as the most important water supply resources in various sectors, including agriculture water, drinking water, and industrial water. Over recent years, however, urban, industrial, and agricultural sewage have mostly been discharged into rivers. Taking into account that rivers have a limited capacity for toleration of pollutants, river water quality assessment is indispensable. In the present study, three water quality indicators namely the National Sanitation Foundation Water Quality Index (NSFWQI), River Pollution Index (RPI), and Weighted Arithmetic Water Quality Index (WAWQI) were used to assess the quality of Garmarood River water.  Sampling was performed at 3 stations along the river during summer and winter of 2019. A variety of parameters namely DO, temperature, BOD, fecal coliform, turbidity, TSS, pH, NH3-N, and phosphate were measured to calculate NSFWQI and RPI indices. The parameters used to measure WAWQI, included TS, NO3-, chloride, total hardness, SO42-, Mg, turbidity, pH, and Ca. The results obtained from analysis of the above-mentioned parameters showed that the value of NSFWQI, RPI, and WAWQI indices fall within the 50.66-75.6, 2.25-5.5 and 48.33-55.92 ranges. The results obtained from all 3 indices are indicative of relatively high quality of water at station 1 and poor quality of water at stations 2 and 3.