Monitoring the Arsenic Concentration in Groundwater Resources, Case Study: Ghezel ozan Water Basin, Kurdistan, Iran

Water resource contamination is one of the major challenges in the way of sustainable development. Arsenic is a dangerous contaminant with adverse effects on human health and is highly restricted by international environmental standards. An unofficial reports indicated the presence of compounds of arsenic in groundwater of rural areas in Ghorveh and Bijar counties of Kurdistan province. The reports noted contamination within the boundaries of the Ghezel ozan water basin in western Iran. These reports caused serious concerns for the residents of these areas. Accordingly, water sampling was done during the summer of 2004 from areas where arsenic contamination was suspected. Nine villages in Bijar and 13 villages in Ghorveh County were considered for water sampling. The arsenic concentration in all water samples was higher than the US EPA maximum contaminant level (50 ppb). Continual droughts in the area have caused local water tables to drop dramatically. Consequently, there has been an increased rate of oxidation in arsenic containing minerals causing arsenic ions (As(3+) and As(5+)) to enter the liquid phase. By considering relatively high amount of annual precipitation in the region, particularly in cold season, a sophisticated method in gathering, maintenance and use of groundwater may be considered for at least a limited period of the year. Furthermore, controlled use of surface water rather than groundwater may lessen arsenic contamination risk.