Application of water quality index (WQI) to assess groundwater quality in Kirkuk governorate, Iraq

Abstract

This study was conducted to evaluate the quality of groundwater using the Water Quality Index (WQI) in the city of Kirkuk, which is located in northern Iraq and is famous for oil production. The study included areas approximately 20 kilometres away from the city centre, which depend mainly on groundwater for human, agricultural and animal use. Nine chemical and physical characteristics of nine wells were determined to estimate the Water Quality Index (WQI) during the summer of 2023. The results showed that most of the chemical and physical parameters of the water samples were within the permissible limits in the standard specifications set by the World Health Organization (WHO) for drinking water. The rates of the studied parameters are (pH = 7.71), (Ec = 805.4), (TDS = 378.67 ppm), (Cl = 85.09 ppm), (NO3 = 40.65 ppm), (SO4 = 138 ppm), (Ca = 93 ppm), (Na=76.3 ppm), (K=3.04 ppm). Regarding the WQI values according to the results of the physical and chemical analyses for each well, they range between (66.6 and 76.17), as the groundwater in the study area is described as good.