Zahedan city lies in one of the most arid areas in southeastern Iran. As the capital of Sistan and Baluchestan province it has grown and urbanized rapidly with a population of over 600,000. All water consumption needs are met by groundwater. In recent years, groundwater has been abstracted from the aquifer at a faster rate than the recharge because of extremely low rainfall, rapid development of the city and high population growth rate, resulting in gradual depletion of storage. The result is a continuous decline in the groundwater levels and deterioration in quality. Consequently, Zahedan is the only city in Iran with two separate pipeline systems for drinking and household requirements due to the increasing salinity of the groundwater aquifer. About 50% of fresh water is imported by tanker from Ladiz village about 100 km southeast of the city and then pumped into the pipeline system that provides drinking water at 13 public stations. Shortage of drinking water has caused interest in developing non-conventiona options, including desalination of brackish groundwater and a water import project. From the beginning of 2003,three small reverse osmosis desalination units have gone into operation for desalination of brackish groundwater to provide a part of the drinking water requirements.

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