Economic feasibility of developing alternative water supplies for agricultural irrigation*

Alternative water sources can be applied to water-stressed agricultural sites to satisfy the increasing water demand. The increased costs associated with the treatment of impaired water, distribution/conveyance/storage, and waste management to meet water quality requirements and regulations are the challenges in developing an alternative water-based irrigation system. This study evaluates the economic feasibility of developing nontraditional water for agriculture and identifies strategies to address the challenges by increasing affordability. In the Southwest United States, reuse of filtered disinfected municipal wastewater offers the most cost-effective option followed by desalinated brackish water, treated produced water, and seawater. High costs, energy demand, concentrate disposal, and soil salinity management are the primary challenges in using alternative water for irrigation. Economic feasibility can be enhanced by implementing autonomous, easy-to-operate, renewable energypowered, decentralized desalination systems. The affordability of developing alternative water for irrigation will increase with reduced treatment and waste disposal costs, depletion of conventional irrigation water supplies, and droughts.