Investigation Water Quality in Arak City Using GIS

This study aim was to evaluate the relationship between the drinking water quality in Arak city regions and the drinking water sources to identify areas with inappropriate quality drinking water and its zoning with the geographic information system (GIS) and planning to address drinking water quality problems. In this research, drinking water from 18 areas in the city was sampled to measure physical and chemical parameters during 2016. Parameter analysis was carried out by the standard water and wastewater. To extract the contamination maps, IDW method was used in GIS environment. The drinking water quality parameters average  for pH, TDS, EC, TH, F, Cl, NO3 and SO4 was 7.4, 50.67(mg/l), 28.840(µS/cm), 28.38(mg/lCaCO3), 17.0(mg/l), 15.95(mg/l), 19.66(mg/l) and 27.49 (mg/l) respectively. The results showed that the highest concentration of pH, TDS, and EC was in the east.  TH is located in the south. The highest amount of F is in the west of the city and F is highest in the south, the highest NO3 and SO4 are located in the south. In general, the comparison of measured values ​​with the set value indicates that the average value of all elements was lower than national standards, but the mean of TDS, TH, and NO3 is higher than global standards.