California looks to sea to tap drinking water

CARLSBAD — Every time drought strikes California, the people of this state cannot help noticing the substantial reservoir of untapped water lapping at their shores — 187 quintillion gallons of it, more or less, shimmering so invitingly in the sun.

Now, for the first time, a major California metropolis is on the verge of turning the Pacific Ocean into an everyday source of drinking water. A $1-billion desalination plant to supply booming San Diego County is under construction here and due to open as early as November, providing a major test of whether Californian cities will be able to resort to the ocean to solve their water woes.

Across the Sun Belt, a technology once dismissed as too expensive and harmful to the environment is getting a second look. Texas, facing persistent dry conditions and a population influx, may build several ocean desalination plants. Florida has one operating already and may be forced to build others as a rising sea invades the state’s freshwater supplies.

In California, small desalination plants are up and running in a handful of towns. Plans are far along for a large plant in Huntington Beach that would supply water to populous Orange County. A mothballed plant in Santa Barbara may soon be reactivated. And more than a dozen communities along the California coast are studying the issue.

Largest ocean desalination plant

The facility being built here will be the largest ocean desalination plant in the Western Hemisphere, producing about 50 million gallons of drinking water a day. So it is under scrutiny for whether it can operate without major problems.

“It was not an easy decision to build this plant,” said Mark Weston, chairman of the agency that supplies water to towns in San Diego County. “But it is turning out to be a spectacular choice. What we thought was on the expensive side 10 years ago is now affordable.”

Still, the plant illustrates many of the hard choices that states and communities face as they consider whether to tap the ocean for drinking water.

In San Diego County, which depends on imported freshwater supplies from the Colorado River and from Northern California, water bills already average about $75 a month. The new plant will drive them up by $5 or so to secure a new supply equal to about seven or eight percent of the county’s water consumption.

The plant will use a huge amount of electricity, increasing the carbon dioxide emissions that cause global warming, which further strains water supplies. And local environmental groups, which fought the plant, fear a substantial impact on sea life.

The company developing the plant here, Poseidon Water, has promised to counter the environmental damage. For instance, it will pay into a California program that finances projects to offset emissions of greenhouse gases.

Still, some scientists and environmental groups contend that if rainy conditions return to California, the plant here and others like it could become white elephants. Santa Barbara, northwest of Los Angeles, built its desalination plant a quarter-century ago and promptly shut it down when rains returned.

Australia is a more spectacular case: it built six huge desalination plants during a dry spell and has largely idled four of them though water customers remain saddled with several billion dollars’ worth of construction bills.

“Our position is that seawater desalination should be the option of last resort,” said Sean Bothwell, an attorney with the California Coastkeeper Alliance, an environmental coalition that has battled California’s turn toward the technology. “We need to fully use all the sustainable supplies that we have available to us first.”