UC Riverside

Water scarcity has become a critical problem in many semi-arid and arid regions. California is located in the arid southwest and is expected to experience more frequent and intense droughts under climate change. Currently, residents of Southern California rely on groundwater and imported water from both the state water project, which transports water from the Bay-Delta, and Colorado River Aqueduct. With concerns over current and future levels of water availability, municipalities and state governments are focusing significantly more attention and resources towards groundwater management strategies and alternative water supplies via desalination and the reuse of municipal wastewater. While the reuse of treated wastewater is not a new concept, concerns over the rising demand for water from population growth, coupled with challenges—both economic and environmental—confronting agencies in their efforts to appropriate new supplies, have made this option significantly more attractive. Consequently, the reuse of treated wastewater presents municipal water and irrigation agencies, including farmers, with the possibility of a low-cost, reliable and environmentally friendly local water source whose value will only increase under expected climate change conditions.

Currently, information relating to groundwater extraction, groundwater use, managed and natural recharge throughout California is limited. Unconstrained use of this source has led to groundwater table depletion, land subsidence, and impact of water quality. Groundwater depletion and degradation of groundwater aquifers results from a lack of effective governance. Moreover, climate change conditions have an immediate impact on the natural recharge in some regions. The coupling of climate change and a growing population presents a challenge to sustainable management of groundwater resources; as demand increases and recharge decreases groundwater levels drop, which results in increased production costs and potential depletion. Thus, municipalities are exploring adding additional resources to their resource portfolios, with cost, quality, and reliability concerns serving as guidelines in this quest. Desalination water, therefore, may become an answer to water shortages due to continual depletion of many groundwater basin and unreliability of imported water—amplified by the climate change.

This research will build upon current research and further explore water supply alternatives that are intended to improve local water supply reliability and provide greater resilience to drought and climate change conditions by evaluating different wastewater treatment technologies and their impacts on municipal wastewater effluents for varying degrees of agricultural applications. In addition, the research will also study the impacts of droughts on municipal wastewater quality and treatment technologies in compliance with state and federal regulations. This research is designed to give water agencies the tools needed to make informed management decisions under future water and climate uncertainties.