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

Abstract

The research aimed to evaluate the surface water quality of Gilgit city by comparing
the actual values of physio-chemical and microbiological parameters with that of the national standards
for drinking water quality of Pakistan. A total of Sixteen surface water samples were gathered from the
study 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 water
quality index, ArcGIS Model Builder and ArcPy were employed. The key informants interviews and
focus group discussions were also conducted to list the water-related problems. The findings of the
water quality index ensured the good quality of collected surface water samples using physicochemical
parameters but the occurrence of microbiological contamination in both rivers declared water unfit for
drinking. 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 authorities
and community. The residents also suggested to repair filtration plants as well as cover the water
storage structures on an urgent basis. The study will be helpful to concerned departments of the study
area to plan their resources and provide their services to the residents efficiently.