The combination of an ever-increasing population and a diminishing usable water supply threatens the sustainability of humanity's existence on a global scale, especially in California, where agriculture is so integral to the state's economy. Due to widespread recognition of this problem, there has been a growing trend in the development of alternative water resources, one of which involves the desalination of salt or brackish waters. Several different desalination technologies exist, including microfiltration, multi-stage flash, and multi-effect distillation.
This senior project investigates the economic viability of implementing reverse osmosis desalination for treatment of agricultural wastewater or other unusable water sources. These water sources might include brackish groundwater or municipal wastewater. The capital and operational costs of implementing such technology were compared to the delivery prices for existing water sources in the San Joaquin and Coachella Valleys and along the Central California Coast. Along with the costs associated with each option, the environmental, social, and political concerns were considered, as well.
Field visits and personal interviews of current desalination plant operators, in conjunction with desalination pricing, were compared to the current cost of irrigation water delivery in the San Joaquin and Coachella Valleys, as well as the Central California Coast. The results showed that the cost of desalination, while significantly less expensive in the past few years, was still too great to offset the relatively low prices of irrigation water delivery. The concern of brine disposal in the Central and Southern California Valleys also poses environmental problems.
Although desalination is not currently economically viable, it seems only a matter of time before either the cost of water becomes too great or the cost of desalination becomes affordable.
