Challenges and Opportunities for Wastewater Reuse in Municipal Consumptions: a Case Study in Tehran Metropolis

Water as one of the world’s most important natural resources, is facing several threats. These are due to some of the serious environmental issues such as climate change, population growth and pollutions. One of the most promising solution to overcome these challenges is alternative water resources such as the sea water, wastewater, and brackish water and similar sources. In allocating the treated wastewater, it should be noted that water demand is not the sole determining parameter. Various economic, social, technical and cultural aspects should also be considered. This study investigated the possibility of wastewater recycling in Greater Tehran and reviewed the existing challenges and opportunities in this regard. Tehran’s annual water consumption is estimated around 1300 million cubic meters, from which 800 million cubic meters is provided by dam reservoirs in the vicinity of the city and the rest is supplied through legal and illegal wells drilled into Tehran aquifer. In the 2030 Country Vision it is predicted that in Tehran a total amount of 850 million cubic meters of treated wastewater would be available. Therefore planning for allocation of this amount of water in agriculture, industry, landscape and aquifer recharge is essential. It is necessary to overcome the obstacles and the negative effects of wastewater reuse, to apply appropriate technologies, to move toward the decentralized wastewater treatment systems, and to enhance the social acceptance.