Zoning of Some Drinking Water Quality Parameters Using GIS (Case Study: Malyer City)

Pollution of drinking water is one of the fields of important concern to environmentalists. Water quality is an indicator of health and welfare of a community. In this research, the concentration and mapping of some quality parameters of drinking water in Malayer city were evaluated using statistical and GIS techniques The study populations were drinking water distribution networks of Malayer. For this purpose, the city divided into several areas so that covered the total urban area. A total of 50 drinking water samples were taken from the drinking water distribution network, during May 2016. The various parameters such as, pH, Electrical conductivity (EC), cations (Na, K), and anions (NO3) were measured. The concentration of nitrate was measured by spectrophotometry and sodium and potassium by flame photometer. The mean values of measured parameters were nitrate 27.61 mg/l, pH 6.79, electrical conductivity 0.69 dS/m, potassium 0.41 mg/l, and sodium 1.37 mg/l.The range ofnitrate levels from obtained samples varied between 19.34 and 47.83 mg/l. All measured parameters for drinking water samples from Malayer were observed to be lower than the WHO standard and the national standard of Iran. With regard to GIS maps, the concentrations of NO3, Na and EC were higher in northern and northwest regions. One the reasons for the high concentration are unsafe disposal of municipal wastewater. In order to prevent the increase of nitrate in the drinking water distribution network, doing of some actions such as no discharge of municipal wastewater to water sources and wastewater treatment seems to be necessary. With attention to the classification of polluted waters with nitrate 20-45 mg/l, drinking water of Malayer city were regarded polluted.