Exploring Advanced Treatment Options for California Water Security

Project Background: California's Water Crisis

California faces immense challenges as climate change and rising water demand continue to strain the state’s available resources. Extended periods of drought, increased evaporation from rising temperatures, groundwater depletion—particularly severe throughout the Central Valley—and a shrinking Colorado River further contribute to water shortages throughout the state. With worsening water quality issues, aging infrastructure, and reservoirs at critical lows, California communities must employ supply-side and demand-side solutions to ensure an affordable, safe, and secure water supply in future years. The following technologies will be pertinent to California's future water security: water recycling technologies (Direct and Indirect Potable Reuse) and desalination processes for seawater and groundwater.

Approach and Recommendations

1. We developed a model in R to calculate the energy requirements, capital costs, and operation & maintenance costs for different water treatment technologies. We applied this model to three water agencies across California: the cities of Bakersfield, Fresno, and Oxnard.
2. Indirect potable reuse is the most cost-effective and climate resilient technology for all three sites. Groundwater desalination is the most affordable option among these technologies; however, it relies on a consistent supply of groundwater, making it unreliable long-term as supplies dwindle.
3. Our water risk assessment determined more work needs to be done. We assessed socioeconomic, environmental, and water risk for each site. Risk scores were not evenly distributed within site boundaries, showing the need for additional research to equitably implement these technologies.