Fresh Water Sought at Sea

With other sources of drinking water drying up, water districts from Los Angeles to San Diego are hoping to build desalination plants to tap the vast resources of the ocean.

Straining the salt from the seawater has long been a dream in drought-prone and fast-growing Southern California. But the costs have always been prohibitive. Now, a new generation of super-fine filters has sharply cut the expense of purifying saltwater, so much so that five local water agencies hope to build plants that would create a supply for more than a million people.

“Ultimately, it is the future of Southern California,” said Steven Erie, director of the Urban Studies and Planning Program at UC San Diego. “No water, and there’s no great Southern California civilization or economy. It’s pretty simple. That’s why they call it ‘liquid gold.’ ”

Desalination, expensive and energy-consuming, has long been a popular water source in the oil-rich nations of the Middle East. During desperate droughts, a handful of California cities, such as Santa Barbara, built expensive plants but quickly mothballed them because of the cost.

Advances in filtration technology over the past decade have drastically reduced the price of desalinated water, though it is still about four times more expensive than groundwater. However, population growth and reduced water from the Colorado River means Californians are thirsty for new sources. Some scientists predict a drought in California and reductions in mountain snowpacks that provide drinking water, making the supply even tighter.

Southern California water officials are embarking on plans to make sewage water clean enough to drink and are even talking about floating bags of river water from Northern California. Scenarios like those make desalinated water look a lot more palatable.

About three years ago, the Metropolitan Water District of Southern California started encouraging local districts to make the move and formulated a plan to subsidize some projects.

“There was a growing sentiment that perhaps desalination could be feasible,” said Adan Ortega Jr., MWD’s vice president for external affairs. “The heart of the strategy for Southern California’s long-term reliability ... is not to put all of our eggs in the proverbial basket. What we need to do is spread our dependence among a variety of resources so that in the event of a prolonged drought, we have more options already in place.”

Around the world, 13,600 desalination plants produce 6.8 billion gallons of water daily, according to U.S. Water News Online, a trade publication. California water officials know of no major seawater desalination plants currently operating in this country, aside from a few tiny facilities on Catalina Island, the Monterey Bay Aquarium and the visitors center of a state park at San Simeon.

Desalination of briny groundwater is relatively common; the Orange County Water District does it to get rid of the minerals from dairy cow waste that contaminate groundwater.

Santa Barbara opened a $34-million seawater desalination plant in 1992 but shut it after three months because of the expense. Eventually, parts of the plant were sold off to other countries. The city keeps the facility in “long-term storage mode,” and will be forced to spend $3 million to reactivate it if a new water supply is needed. Morro Bay also built a desalination facility during the drought of the early 1990s but has not used it since 1995.

Despite those setbacks, the idea of desalination is making a strong comeback.

The nation’s largest seawater desalination plant currently is being built on the east side of Tampa Bay. The plant became necessary even though Florida is engorged with water because so much of the region’s groundwater was being consumed that fragile ecosystems were being dramatically altered. Ponds were disappearing, and swamps were drying up. The $108-million project will create 25 million gallons of drinking water a day--10% of the local supply--when it opens in December and a second plant is under consideration, said Don Lindeman, project manager at Tampa Bay Water.

Last April in Texas, Gov. Rick Perry asked the Texas Water Development Board to study the viability of seawater desalination. In California, hundreds of millions of dollars will be available for desalination projects if voters in November approve Proposition 50, a $3.4-billion water-quality bond measure.

Assemblyman Bob Hertzberg (D-Van Nuys) has proposed the creation of a state task force to assess seawater desalination throughout California. Though his bill unanimously passed the Assembly, it has stalled in the Senate because of its $600,000 price tag.

In Southern California, MWD is reviewing proposals to build plants in Dana Point, Carlsbad in San Diego County and several coastal locations in Los Angeles County. This fall, the agency will decide whether to subsidize some or all of these plants.

The Los Angeles Department of Water and Power has proposed a $70-million plant in Playa del Rey that would produce 12 million gallons of water a day.

West Basin Municipal Water District has proposed building a 20-million-gallon per day plant in either Redondo Beach or El Segundo, and the Long Beach Water Department wants to build a $74-million plant that would create 10 million gallons of water a day.

Municipal Water District of Orange County’s proposed plant in Dana Point would supply 27 million gallons of water a day, enough for 250,000 people. The plant, expected to be up and running in 2007, would cost $130 million to $200 million.

Though that’s a huge expenditure, local officials say in case of severe shortage, the plant’s value would be immeasurable.

“One of the attractions of a desalination plant in Orange County is that it would be drought-proof. If you had an earthquake that severed aqueducts from the Colorado River or [Northern California], you would still have a source of water in Orange County,” said Keith Coolidge, spokesman for the district.

As in other desalination plants, ocean water off Dana Point would be pumped through ultra-fine filters to remove the salt and other minerals, a process known as reverse osmosis. The water would then be piped to reservoirs, and eventually to South County homes and businesses.

The San Diego County Water Authority announced earlier this month that it supports building two plants in the area. The first, a proposed $242-million plant in Carlsbad, would create 50 million gallons of drinking water a day by 2006. The proposal has been submitted to MWD to see if it is eligible for a subsidy. The second is slated for Chula Vista.

Despite the technological improvements, desalination has critics, who say that it is extremely energy-consuming and produces a super-salty brine that must be disposed of.

Joe Bernosky, a water-quality engineer with the American Water Works Assn., said that as the technology becomes more commonplace, it will become more energy efficient. Still to be addressed, he said, is what to do with the brine removed by the filters.

“It is a consideration, but it tends to be less so than most people think,” Bernosky said. In Tampa, the brine will be discharged into the ocean with the cooling water from a power plant, which dilutes it immediately. The resulting addition of brine to the ocean, according to Bernosky, would be so diluted that it would have no impact.

Others worry that creating more water dilutes the emphasis on conservation that some people feel is key to long-term planning.

“It would [create] a false sense of security,” said Jay Negrin, a Southern California water-quality biologist. “I think the perception could easily be that the infrastructure is in place and now we don’t have anything to worry about. The bottom line is we still live in a desert.”