WATER QUALITY ASSESSMENT USING WATER QUALITY INDEX: A CASE STUDY OF HIGH ALTITUDE AREA, GILGIT CITY, GILGIT BALTISTAN, PAKISTAN

The research aimed to evaluate the surface water quality of Gilgit city by comparingthe actual values of physio-chemical and microbiological parameters with that of the national standardsfor drinking water quality of Pakistan. A total of Sixteen surface water samples were gathered from thestudy area to analyze their quality. Multiple parameters including fluoride, hardness, pH, nitrite,nitrate, chloride, and TDS were mapped spatially using inverse distance weighting. To compute waterquality index, ArcGIS Model Builder and ArcPy were employed. The key informants interviews andfocus group discussions were also conducted to list the water-related problems. The findings of thewater quality index ensured the good quality of collected surface water samples using physicochemicalparameters but the occurrence of microbiological contamination in both rivers declared water unfit fordrinking. It showed that the water of the city is being contaminated due to anthropogenic activities.The mixing of wastewater into drinking water sources was also reported by the respective authoritiesand community. The residents also suggested to repair filtration plants as well as cover the waterstorage structures on an urgent basis. The study will be helpful to concerned departments of the studyarea to plan their resources and provide their services to the residents efficiently.