Iranian Journal of

Background and Objective: Groundwater is the primary water source for drinking and agricultural activities in arid and semi-arid regions. Rainfall, land use, geological structure, aquifer mineralogy, and duration of water contact with the environment in the basement are the main factors affecting the chemical quality of groundwater. This study aimed to determine the physicochemical properties of groundwater by considering the water quality index (WQI) and its quality assessment for drinking water.
Materials and Methods: In this study, 71 wells of Kashan were sampled in summer 2020 with three samplings from each well, and physical and chemical parameters were studied, water quality index was determined using mathematical methods, and Pearson correlation coefficient was determined. Correlation analysis was used. Finally, the collected data were analyzed using SPSS-16 software, Excel 2013, and statistical tests. 
Results: The calculated WQI of 71 wells in Kashan shows that 67% of the wells were of excellent quality, and 33% were of good quality in terms of water quality parameters. In total, out of 71 samples, the numerical index of water quality was 44.94, and the water was of excellent quality.
Conclusion: The results show that ions such as sodium, sulfate, and chlorine are directly related to the counting in an area and increase the concentrations of EC and TDS, and can impair the balance of anionic and cationic aqueous solution. It was also found that more than half of the wells have excellent quality due to using water wells for drinking.