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Debatable Need Predictions
"The largest, least expensive, and most environmentally sound source of water to meet California's future needs is the water currently being wasted in every sector of the economy," states the Pacific Institute's Waste Not Want Not: The Potential for Urban Conservation in California (2003). About a third of the state's urban water use alone can be saved with existing technology, the report estimates. Agriculture also offers big water conservation opportunities.

What's more, the dire expectations of water shortages may be way off. "Note that California is using less water today than ten years ago," Gleick told a conference on desalination held at the Aquarium of the Pacific in Long Beach on October 5. Although the state's economy has grown and its population has risen to more than 34 million from 21.5 million in 1975, statewide water use has decreased, he said. Los Angeles has 700,000 more residents now than it did 20 years ago, but water demand has not risen.

There are two ways to desalt seawater: by distillation or by reverse osmosis. All the plants proposed in California would use reverse osmosis, a process in which pressure is applied to seawater to force it through membranes that allow only water molecules to pass through. The remaining brine, along with minerals and residual chemicals used in the process, is discharged in a waste stream. Two gallons of saltwater will produce one gallon of drinking water. Because desalted water comes out tasteless, minerals must be added to make it palatable.

Some of the proposed plants would be built next to power plants with once-through cooling systems: they take in seawater to cool condensers, then discharge it through an outfall. The desalination plant would be connected to this outfall to collect some of the cooling water for desalting. The brine would be mixed with the power plant's discharge.

Nikolay Voutchkov, senior vice president of technical services for Poseidon Resources Corporation, wrote in the July/August 2005 issue of Asian Water that "co-location of desalination plants with large power generation stations may yield significant cost-savings and further reduce the cost of desalinated water." Tom Luster, environmental analyst for the Coastal Commission, meanwhile, says that such tie-ins could delay the transition coastal power plants must make from once-through cooling, which harms marine life. Many of these plants were built in the 1950s and '60s, when neither energy nor the environment were big public issues. In sucking in water from the ocean, they kill fish and other marine life that is trapped against the intake screen (impingement) or pulled through the system (entrainment). The California Ocean Protection Council has called for once-through cooling to be phased out, the U.S. Environmental Protection Agency has ordered a severe reduction in impingement and entrainment, and three coastal power plants have already switched to a cooling system that uses air instead of water. A co-located desalination plant could lock in a harmful and obsolete technology, Luster said.

What's Best for the 21st Century?
In the past, when water districts wanted more water, they got it from northern rivers or the Sierra by building dams and pipelines, with federal and state governments paying a big share of the cost. Desalination follows that tradition: it would expand water supplies by developing a new water source that requires hard structures. Those on the go-slow side of the debate hold that the 21st century demands an approach that makes the most of the water already available.

A simple measure such as replacing old toilets that use six gallons per flush with the kind that use 1.6 gallons per flush would save 420,000 acre-feet of high-quality water that now goes down the drain, the Pacific Institute has calculated, and householders would save on water bills. (Even more efficient toilets, which use 1.3 gallon a flush, are now standard in Europe and Japan and available here.) Even more could be saved by simple changes in irrigation; most household water use is outdoors.

Conner Everts co-chairs the Desal Response Group, a network brought together in 2004 by southern California utilities interested in ocean water desalination. "We have been meeting ever since because we have more questions than the utilities have answers," he said. This group is trying to make sure that as California moves toward desalination, citizens and decision-makers understand the key issues, and that these issues are addressed. The network includes water policy experts, local government representatives, staff of permitting agencies, utility districts, and citizen advocates concerned with food, water, the fishing industry, and ecosystems. "I've met people from organizations I never heard of before and we have shared our expertise in our areas of concern," said Joe Geever, the Surfrider Foundation's manager for the South Coast.
Privatization of water is a big concern. "If your water system is operated by a company with headquarters in Germany and that company is trying to divest itself of its water holdings in America, whom do you call when you need something?" Everts asks.

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