Amid historic drought, California expected to approve $140 million desalination plant

[October 13, 2022]  By Daniel Trotta

(Reuters) - A $140 million desalination plant is expected to be approved by California regulators on Thursday as the U.S. state contends with how to convert ocean water into drinking water amid the worst drought in 1,200 years.

Just five months ago, the Coastal Commission by an 11-0 vote rejected a privately owned plant that would have been 10 times the size of the proposed South Coast Water District's Doheny Ocean Desalination Project in Orange County, just south of Los Angeles.

With environmental protection a concern, experts say smaller can be better.

"It's more nimble. The future is going to be all about modular solutions," said Newsha Ajami, a researcher at Berkeley Lab's Earth & Environmental Sciences Area.

Instead of relying on water pumped from hundreds of miles (km) away, through the State Water Project or the Colorado River, the South Coast Water District would now have its own water supply. The smaller scale also cuts down on the environmental impact and will clear regulatory obstacles more easily.

"We're watching what's happening at the Colorado River, and it's not good," said Rick Shintaku, general manager of the South Coast Water District, referring to the extreme drought that may force cutbacks of 15% to 30% for Californians and other Colorado River users. "Desalination could be part of that solution for water reliability for a broad region."

The Doheny plant would produce 5 million gallons of drinking water per day, more than enough to meet the needs of the district's 35,000 people.

The district will still buy water from the regional wholesaler, Metropolitan Water District of Southern California, keeping about 40% of the desalination project's output for itself and selling 60% to neighboring providers.

The proposed site is 25 miles (40 km) down the coast from where the Coastal Commission rejected a larger proposal by Poseidon Water, the infrastructure arm of Canada's Brookfield Asset Management.

Environmental groups that protested the Poseidon project have been largely silent this time. The Coastal Commission staff, which recommended rejecting Poseidon, favors building Doheny, which would be the 12th desalination plant approved by the regulator.

Poseidon's plant would have sucked in massive amounts of water from above the ocean floor, killing sea life, according to Coastal Commission assessments. The Doheny plant will use a sub-surface intake that creates a barely perceptible current.
 

At Doheny, the brine that results from desalination will be mingled with the discharge of a neighboring wastewater treatment plant, mitigating the harmful effects of having two diffusers pumping effluent into the sea.

Tom Luster, a senior environmental scientist on the Coastal Commission staff, said the state is studying locations where plants similar to Doheny might be feasible up and down the coast.

"It's a fairly small-scale facility, but it provides for the local needs and it frees up water for other communities," Luster said.

(Reporting by Daniel Trotta; editing by Donna Bryson and Raju Gopalakrishnan)

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