Evaluation of Nitrate Contaminaion of Drinking Water Wells in the City of Qom

Groundwater is the only vital source of water for millions of people around the world and its contamination has dire impacts on human health, industrial activities, agriculture, and the environment. The drinking water in the City of Qom is supplied from neighboring water basins transferred by interbasin water transimission facilities and from water wells within the city. The growing demands and the consequent increasing water scarcity have augmented and foregrounded the significant role played by the water wells in this city. Nitrate as a widespread pollutant originates from human activities and the dumped wastes that lead to the gradual degradation of groundwater resources, which might go undetected for years. On the other hand, remediation of polluted aquifers is a formidable, cost-intensive, and, at times, impossible endeavor. In this study, groundwater resources in the city of Qom were investigated in terms of their nitrate concentration. For this purpose, 600 groundwater samples collected from 2006 to 2013 by the Qom Water and Sewage Company were used, 136 of which were found to be polluted with nitrate. In order to validate the data thus obtained and to identify the contaminated areas, additional samples were collected from 27 wells in December 2013 and subjected to the relevant analysis. The latter analysis revealed a mean nitrate concentration of 74 mg/L and a standard deviation of 37 mg/L, with nitrate contamination detected in 19 wells accounting for 70% of the sampling sites. Generally, the results indicate that the aquifers within the city of Qom suffer from nitrate contamination.