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| | MAY 1, 2003 SPECIAL REPORT: ENVIROTECH Treasure from the Deep: Drinking Water Thanks to huge technology improvements, desalination is fast becoming the answer to "Where will we get the water to support growth?"
In the thirsty, growing cities of Southern California, however, simple conservation simply won't do the trick. This region imports more than 80% of its water from neighboring states. And even though it jealously guards those arrangements, they won't be enough to compensate for the rapid growth that lies just ahead: San Diego County's population alone is projected to rise about 29% by 2020, from 2.84 million to 3.67 million. California has a crisis on its hands. According to the San Diego Water Authority, water demand in its area will grow 20% by 2020, from 650,000 acre-feet annually to nearly 800,000 acre-feet. (An acre-foot is the volume of water that would stand a foot deep over an acre. That translates into 325,551 gallons, enough to supply five people for a year.) DRINKING THE SEA. Drastic times call for drastic measures, so state water agencies are turning to desalination, a technology that makes ocean and brackish water drinkable by stripping it of salt and other minerals. California has plans in various stages to build 13 desalination plants along its coastline. The projects will cost billions, but planners say they'll provide a far more reliable supply for California residents than waiting for Mother Nature to adjust her weather patterns. Since just 3% of water on earth is fresh, this is a step that would have to be taken anyway as the global population grows. "Desalination will create a drought-proof supply of water," says Bob Yamada, the San Diego Water Authority's seawater-desalination program manager. He adds that 20 years from now, 10% to 20% of the state's water could come from the ocean. The American Water Works Assn., a Denver-based nonprofit dedicated to improving drinking-water quality and supply, predicts that the market for desalination plants and equipment, now just $2 billion, will grow to more than $70 billion over the next two decades. Not surprisingly, such growth potential has attracted the world's largest construction outfits. Leading the charge in the U.S. is Poseidon Resources, a privately held water-management concern. Poseidon was lead developer on a just-completed $110 million desalination plant in Florida's Tampa Bay. It's also working on projects in San Diego, Huntington Beach, Calif., and Freeport, Tex. OSMOSIS IN REVERSE. Besides its water expertise, Poseidon takes on much of the risk of building desalination plants --- a great benefit to municipalities facing severe budget shortfalls. In San Diego, it will build, own, and operate the plant for five years before turning it over to the water authority. Other big players in this industry include construction giant Stone & Webster, a division of Shaw Corp. (SGR ); Israel's Engel Construction; Osmonics, which in November, 2002, was purchased by GE (GE ); and Ionics (ION ) in Watertown, Mass. To understand how desalination works, think back to your high school biology class: The principle of osmosis says if you divide two bodies of water with different concentrations of salt or other minerals by a semipermeable membrane, the water will flow between the two parts to equalize the concentration. Desalination achieves the opposite, using a technique called reverse osmosis. Water from the ocean is forced at a very high pressure -- about 1,000 pounds per square inch -- through a dense membrane. The water molecules, which are smaller than most impurities, are able to pass through, while salt and other minerals can't. The remaining liquid is discharged as brine. The newest state-of-the art plant in Tampa Bay, which came online in February, produces 25 million gallons of fresh water a day and serves 2 million people.
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