Our project investigates existing and proposed seawater desalination projects in two case study sites including Carlsbad in Southern California and Monterey Bay in central California.
Seawater desalination plant in Carlsbad, California
Carlsbad is a seaside resort of 112,299 residents in Southern California and part of the San Diego County Water Authority district. The newly constructed seawater desalination plant is the first high-capacity (50mgd) seawater desalination facility in California and started operation in December 2015. At full capacity, the seawater desalination plant uses about 300 million gallons per day (mgd) of seawater via an open ocean intake technology. The desalination process uses about 100 mgd of seawater to produce 50 mgd of high quality drinking water via reverse osmosis, and 50 mgd of salty brine with a concentration of about 67,000 ppm (twice the concentration of incoming seawater). Prior to discharge, the brine is diluted with the additional 200 mgd of intake seawater. The plant shares the existing seawater intake and outfall infrastructure of the Encina power plant located next to the new desalination plant. More information on the plant can be found here.
Operator: Poseidon Resources; Water Purchaser: San Diego County Water Authority; Total Costs: $984 million
Operator: Poseidon Resources; Water Purchaser: San Diego County Water Authority; Total Costs: $984 million
Proposed seawater desalination plants around Monterey Bay
Monterey Bay is located in central California and part of the Monterey Bay National Marine Sanctuary. The Monterey Bay is part of the Monterey Bay National Marine Sanctuary, a federal marine protected area since 1992 governed by the National Oceanic and Atmospheric Administration (NOAA). The Sanctuary encompasses a shoreline lengths of 276 miles and 6,094 square statute miles). The marine environment in the Monterey Bay contains one of North America’s largest underwater canyons and highly diverse and productive ecosystem. Commercial fishing and marine recreation are allowed within the sanctuary, but oil drilling, ocean Dumping, and sea bed mining are prohibited. As construction, water intake and brine discharge by seawater desalination plants can affect marine ecosystems, seawater desalination is recognized as a regional issue of concern and the Sanctuary has developed a Desalination Action Plan that calls for a regional planning effort for desalination within the boundaries of the Sanctuary.Freshwater supply in the area primarily relies a number of groundwater basins and surface water systems. Groundwater accounts for roughly for 75 percent of the annual water supply in the region. Three small desalination plants are already operating in the Sanctuary: Moss Landing (<0.5 million gallons per day (MGD), Marina (0.45 MGD), Monterey Bay Aquarium (0.040 MGD). Five seawater desalination plants have been proposed in recent years in communities surrounding the Monterey Bay to diversify water supply sources with capacities of 2.5 to 22 MGD