They used to call California ocean desalination a disaster. But water crisis brings new look at desalination, which has been slow to take off in the San Francisco Bay Area.
It didn’t turn out that long ago, before the water crisis. But now the city of Vallejo is looking at whether its first attempt at industrial-scale desalination may not be an expensive mistake.
It may even be a better option than drawing from the water at the ocean, which it has done for more than a century.
Vallejo’s desalination plant, now operating more or less in defiance of California’s water code, is a symbol of a new approach to water: The city hopes to use it as an economic stimulus in the face of drought.
It is a far cry from decades ago, when environmentalists and developers decried desalination as an expensive, environmentally irresponsible way to use a limited water supply.
“This water use may not be what everyone thought,” said Michael G. Donley, Vallejo’s director of engineering and sustainability. “There are some real benefits to our city.”
Vallejo is the first city in California to use a new industrial-scale method called “reverse osmosis” to extract water from the ocean using a technique that diverts salt water from a salty brine to an alkaline solution to get pure freshwater.
In the 1950s, it was the San Francisco Bay Area that dominated the business of desalinating ocean water, using the technology to produce the state’s first new water source since the late 1800s. When the technology became common on the West Coast, the San Francisco Bay Area, particularly the cities of Vallejo and San Mateo, started to emerge as the leading desalination center.
But California’s legislature, then dominated by Democrats, passed strict regulation that made it difficult for cities to use the technology and encouraged the federal government to develop more efficient methods.
After years of legal challenges, the U.S. Army Corps of Engineers, which oversees the California coast, approved an expanded use of reverse osmosis to desalinate ocean water in San Francisco Bay. But environmentalists and advocates for the environment had long opposed the technology after learning that its salty water would leak into the ocean when the brine evaporated.