Carlsbad desalination plan
Chris Stiedemann of Poseidon Water looks over the giant filers that remove microscopic impurities from the seawater. Photo by Chris Jennewein

The San Diego Regional Water Quality Control Board issued a permit Wednesday to develop and install permanent seawater intake and discharge facilities at the Claude “Bud” Lewis Desalination Plant in Carlsbad.

The plant currently produces roughly 50 million gallons of potable water each day for use across San Diego County, but draws most of its water from the Agua Hedionda Lagoon, which is then circulated to the plant by the Encina Power Station.

Under the National Pollution Discharge Elimination System permit, the plant will continue to draw from the lagoon while the San Diego County Water Authority and plant owner Poseidon Water develop stand-alone facilities for seawater intake and discharge. According to the Water Authority, the new facilities are necessary for the plant’s long-term desalination operations.

“We are very thankful to the Regional Water Quality Control Board for supporting the environmental enhancements of the Carlsbad project and water supply reliability for San Diego County,” said Poseidon Water CEO Carlos Riva. “This plant will continue to be a vital regional resource for decades to come and an example of how environmental stewardship can go hand-in-hand with water supply sustainability.”

The Water Authority estimates that the transition to the stand-alone facilities will take roughly four years. Installation of the new fish-friendly intake and discharge pumps is scheduled to begin by the middle of next year, while the new system is expected to be connected by the end of 2023.

The Water Authority said it is seeking partial state funding for the new facilities, which are expected to cost between $66 million and $83 million.

The plant has produced more than 46 billion gallons of drinkable water since opening in 2015. Currently, the plant supplies roughly 10 percent of the county’s water. The Water Authority and Poseidon Water signed a 30-year deal in 2012 to produce more than 18 billion gallons of potable water each year, enough for roughly 400,000 people.

— City News Service

Chris Jennewein

Chris Jennewein is Editor & Publisher of Times of San Diego.