For decades, desalting Pacific Ocean water has been the dream solution for California’s lack of water. The technology exists, and some small plants already are operating.
But officials say the dream more likely will have to wait until at least the next generation.
“It’s still too expensive,” said Jerry Gewe, director of water resources for the Los Angeles Department of Water and Power.
An acre-foot of desalinated water would cost $900 to $2,000, according to officials in Los Angeles, which expects to complete a pilot plant this year.
By contrast, water received from the Sacramento-San Joaquin delta through state pipelines costs $400 an acre foot, water officials say.
The U.S. Navy’s aircraft carriers desalt water for on-board use, but they also have nuclear generators for power. Saudi Arabia, Kuwait and the United Arab Emirates depend almost exclusively on ocean water, but the oil-rich Persian Gulf nations have no cheaper options.
Santa Barbara is one of three U.S. municipalities that have built desalination plants, but the city uses it only during droughts. Los Angeles does not envision a full-scale facility until after the turn of the century.
The high cost of desalination is a result of the huge amounts of energy required. Water has to be pumped from the sea to the plant and even after the salt is removed, the water must undergo conventional purification treatment.
Disposing of the thick brine left by desalting is another costly concern.
Yet as water from other sources gets increasingly scarce and expensive, desalting is expected to become ever more attractive, even hundreds of miles from the sea.
“Ultimately, we’ll all be going to the ocean,” said Patricia Mulroy, general manager of the Southern Nevada Water Authority.
