The majority of the population of Kalar use groundwater as their source of water supply. Along with the high population growth from less than 10 thousand in 1977 to around 250 thousand in 2020, this has raised water demand. On the other hand, there is a great deal of pressure on water resources due to the inadequacy of water stations supplying the required water and the extensive use of groundwater. All this makes it necessary to investigate the physical and geochemical features of groundwater and the potential pollution in the region in order to provide the requirements for future expansion. The present research involves an investigation of the quality of groundwater in Kalar, Iraq using GlSs and hydro-geochemical methods. In the present research, samples of drinking water were collected from 28 wells distributed properly around the city and investigated in terms of physico-chemical features. The results of the analyses were compared to the standards set within Iraq and by WHO with regard to drinking water. The chemical analysis involved elements such as Beryllium (Be), Aluminum (Al), Copper (Cu), Arsenic (As), Cadmium (Cd) and Barium (Ba), and the physical analysis involved three tests: total dissolved solids (TDS), total hardness (TH) and electro-conductivity (EC). The spatial distribution maps of a range of quality parameters were utilized for that purpose. The Groundwater Quality map of Kalar aquifer without trace elements indicates that high-quality groundwater exists in the eastern and central region of the study area. The values of groundwater quality ranged between 35% and 84%, demonstrating that the area under investigation, of around 22 km2, provided acceptable quality for drinking and optimal quality for irrigation and other domestic purposes. The samples from 27 of the wells exceeded the Iraqi standard for drinking water for Ca2+ and TH, and low quality was reported in other parts because of excessive total alkalinity values. This may have resulted from geological units, industrial operations in the area or solute inputs induced by human activities. The analytical results on trace elements indicated that the concentration of Selenium, Arsenic and Lead in certain groundwater samples was higher than the Iraqi and WHO standards for drinking water. On that basis, anthropogenic and industrial activities in the area, including groundwater abstraction and wastewater effluents, seemed to exhibit great effects on the quality of groundwater. The findings of the present research can contribute to an understanding of the excellence of groundwater resources for development of an appropriate management plan. Moreover, the public can benefit from the acknowledgement of water quality investigation as a helpful tool in the field of water management.
