REGIONAL REPORT : Focus on Sea as Tap Water Stirs Talk of Risk : Drought: Desalination is viewed as a way to quench the needs of Californians. But byproducts of the plants, such as super-salty brine and smog, could harm the ecosystem.

COSTA MESA —  For nearly a century, Southern Californians have outwitted the climate, going to extraordinary lengths to quench their enormous thirst. They have punched holes through mountains, carved channels in the desert floor, drained distant rivers and lakes and lifted water up steep passes.

Yet after all these Herculean efforts, perhaps the simplest and only drought-proof option for overcoming the chronic water shortage lies right at our doorstep, in the vast, salty Pacific. In a relentless hunt for new sources of drinking water, communities from Monterey to San Diego are casting an eye toward ocean waters.

The giant Metropolitan Water District hopes to construct one of the world’s largest seawater desalination plants--producing 80 million gallons of fresh water daily--somewhere on the Southern California shoreline by 1997. At least seven others are proposed along the southern and central coast, including Huntington Beach, Ventura and San Diego Bay, while three began operating the past year in Santa Barbara, Morro Bay and on Santa Catalina Island.

But the flurry of proposals has triggered worries that the long-term ecological effects of transforming seawater to tap water are poorly understood, and that the push to find new sources might result in ill-conceived projects.

Marine researchers and state authorities are warning that serious questions about the impacts of these surf-to-sink operations remain unanswered, from their repercussions on fish to their contribution to smog.

Each day, a desalting plant pumps millions of gallons of brine--a dense, super-salty solution--into the ocean or its bays, where it might harm creatures that are vital links in the sea’s chain of life.

“Disposal of brine is a new concept, and it is the area with the most potential for problems,” said John Largier, an assistant research oceanographer with Scripps Institution of Oceanography at UC San Diego. “There are things that would have to be watched, subtle things you wouldn’t readily notice.”

Ocean creatures--which are ultra-sensitive to slight changes in salinity, light, temperature, oxygen and turbidity--could be poisoned or smothered if the heavy brine settles on the bottom. When pumped into sheltered waters, large amounts of brine might overpower a bay or estuary with salt, or alter currents, which in turn would reshape the ecosystem. Also, drawing in millions of gallons of seawater would trap fish and their eggs.

Spills of hazardous chemicals, such as chlorine and acids, also are possible, although considered unlikely by many engineers. Others worry that the industrial plants will be an ugly, noisy blight on an already cluttered coastline.

Desalination plants consume so much energy that they could contribute to smog--the Southland’s most vexing environmental problem--and increase carbon dioxide from power plants that some scientists say helps cause global warming. Producing 1,000 gallons of desalted water would use as much electricity as an average California household consumes in a day.

“The urban coastal zone is already under tremendous assault, so we must do this very slowly,” said Bob Sulnick, executive director of American Oceans Campaign, a Santa Monica-based environmental group.

“I’m not opposing desalination,” he said. “We are having a freshwater crisis and it certainly needs to be considered very seriously. But what concerns me in this engineering of nature is that (proponents) get a point of view, and then try to go out and prove it. The environmental review and analysis must be done very thoroughly.”

Despite the uncertainties and drawbacks, Southern California water suppliers maintain that desalination is probably the most benign of all alternatives for new water supplies, such as building more canals to drain the ailing Sacramento-San Joaquin River Delta.

“With the apparent benefits and the minimal impacts, it looks like a good deal. But admittedly we haven’t done work on the environmental impacts yet,” said Mark Skowronski, a senior research scientist at Southern California Edison.

The utility built a small desalination plant on Catalina Island last year and is teaming with the MWD to plan a larger demonstration plant near its Huntington Beach electric plant.

“I can’t see where there would be any significant effects on the ocean, given the low increases in salinity,” Skowronski said. “In fact, a very serious concern is the opposite--we have to be very careful as to the quality of the water coming into the plant since the ocean contains bacteria and other substances.”

If all eight of the proposed ventures along the central and Southern California coastline are built, about 190 million gallons of water would be sucked from the ocean each day. This could supply about 4% of Southern California’s water, and the plants would pump back an estimated 65 million gallons of brine daily.

Normal ocean waters are about 3.3% saline, while the brine is 4.4% to 8%--about the same concentration as if 100 buckets of salt were tossed into a large swimming pool.

The extra salinity would be fatal to some marine life, especially the small, floor-dwelling animals and plants that provide food for larger species.

“With brine, if it doesn’t mix properly, it will go to the bottom and sort of spread out like a carpet. These animals are used to having so much salinity in their seawater, just like we’re used to having so much oxygen in our air, so if the salinity is too high, it’s a poison,” Largier said.

Early computer models at moderately sized desalination plants, such as the new one in Santa Barbara, show that ocean waters are impacted within about 120 feet of the pipeline, said Michael Higgins, an associate engineer at the state’s San Luis Obispo regional water board. The potential effects of larger plants have not been studied.

Many marine experts, including Largier, believe that the discharge would mix so quickly in the open ocean that the salt would be almost instantly undetectable. But they acknowledge that they are only speculating, and that no one knows how it will react, especially over time.

A report about to be completed by the California Coastal Commission staff indicates that the agency will look unfavorably on desalting plants near kelp beds or other sensitive marine areas.

“We would particularly look at where a plant is located,” said Cy Oggins, a Coastal Commission staff member. “We would be concerned if it is sited in an area of biological significance, such as the new marine sanctuary off Monterey.”

The giant plant the MWD would like to build within five years would unload 40 million gallons of brine daily into the ocean.

Jeffrey Cross, director of the Southern California Coastal Water Research Project, said that although he believes that pumping brine into the open ocean would have minimal impact, “I would have concerns in an enclosed bay. It’s like putting the discharge into a lake instead of the ocean--the denser stuff is going to sink.”

San Diego engineers are performing computer modeling to see if a proposed 30-million-gallon-a-day desalting plant next to a power plant in Chula Vista would harm San Diego Bay.

“We need to figure out what incremental impact it would have on the bay’s total salinity,” said Gordon Hess, resources planning director at the San Diego County Water Authority.

The environmental challenges are not necessarily insurmountable. Modern engineering can probably resolve many of the threats.

The trick is to protect the environment without inflicting exorbitant price tags. “It can be done. But it’s the cost that’s a concern,” said David Dean, a mechanical engineer at the MWD.

Still, whenever harvesting more natural resources, some sacrifices are inevitable. “If we are going to have a civilization like this, we’re going to have wastes, which means we have to accept some type of environmental degradation,” Cross said. “And they can only go three places--into the water, the air or the land.”

FROM Surf TO Sink

Turning seawater into tap water seems to be a simple, plentiful solution to local water woes. However, desalination costs are high, the contribution to the water supply minimal and the environmental impact uncertain.

Environmental Concerns

Little is known about how desalination affects the ocean, even though countries such as Saudi Arabia have used it for years. Some concerns and possible solutions:

1) Intake

Concern: Fish, other marine life get sucked into pipes during intake of seawater.

Impact: Might be marginal. Existing power plants draw more water than desalination plants, yet are relatively benign.

2) Pipelines

Concern: Copper, other harmful metals could corrode and be discharged into ocean.

Solution: Use safer materials, such as polyethylene or aluminum.

3) Chemicals

Concern: Chlorine and other toxic chemicals used to treat seawater and clean equipment could spill into the ocean.

Solution: Leak-detection, spill-containment systems could minimize chance of accidents. New technologies could reduce need for harsh chemicals.

4) Air Pollution

Concern: Producing electricity to desalt water would emit smog-causing fumes and global-warming gases.

Solution: Desalination plants could be teamed with power plants that are being equipped with gas turbines to cut emissions 90%.

5) Brine Discharge

Concerns for marine life:

* High salt content.

* Brine could sink and agitate ocean floor sediments, blocking sunlight.

* Metals normally diluted in seawater could become concentrated and poisonous.

* Low oxygen content.

* Discharge could alter currents and circulation patterns in bays and estuaries.

Solution: Mix brine with waste water from power or sewage plants, making it more buoyant, and diluting salt and metals. Avoid discharging into bays or other sensitive waters.

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How Desalination Works

There are two main methods of turning seawater into drinking water.

Reverse osmosis: Seawater is forced through a filter that traps salts, producing fresh water.

Distillation: Seawater is boiled, producing salt-free steam that condenses into fresh water.

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How Salty Is Water?

Saltiness for five gallons of: Tap water: About 1 tablespoon Ocean water: About 3 cups Brine: About 5 cups *

Where Plants Are in California

The Metropolitan Water District may build an 80-million-gallons-a-day desalination plant in 1997 at a power plant somewhere along Southern California’s coast, after building a 5-million-gallon-a-day test plant in Huntington Beach, perhaps in 1994. Other plants in gallons per day: Existing San Simeon: 40,000 gallons Morro Bay: 600,000 gallons Santa Barbara: 6.7 million gallons San Nicholas Island: 24,000 gallons Santa Catalina Island: 132,000 gallons Proposed Sand City: 20,000 gallons Monterey Bay Aquarium: 43,000 gallons Monterey: 3 million to 7 million gallons Lompoc: 326,000 to 1.3 million gallons Ventura: 6 million gallons Huntington Beach: 5 million gallons San Diego Bay: 30 million gallons Note: Several small offshore oil platform plants not shown.

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World’s Largest Desalination Plants By gallons of water produced per day: 1) Al Jubail, Saudi Arabia: 288 million gallons 2) Doha West, Kuwait: 115 million gallons 3) Abu Dhabi, United Arab Emirates: 91 million gallons 4) Az-Zour South, Kuwait: 77 million gallons 5) Dubai, United Arab Emirates: 72 million gallons *

A Partial Solution

Proposed desalination plants won’t eliminate Southern California’s dependency on water imports, but will provide a drought-proof, albeit expensive, source of water:

A Drop in the Bucket

Proposed desalination plants would provide only 3% of the region’s daily water needs*. Gallons per day (Current sources) Total daily use: 3.6 billion Imported: 2.2 billion Local: 1.2 billion Reclaimed: 205 million From desalination: 121 million * For urban portions of Los Angeles, Orange, San Diego, Riverside, San Bernardino and Ventura counties

Costly Now, Cheaper Later

Technological advances are expected to bring desalination costs down. Cost of 1,000 gallons Local: $0.34 Imported: $1.00 Reclaimed: $1.69 Desalination: $4.60 Tankered water: $7.67 Alaskan Pipeline: $12.27 Note: 1992 costs; may vary depending on project or other factors

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Sea Life: Bottom-Dwellers at Risk?

If brine from desalination plants has adverse effects, scientists expect creatures on the ocean floor would be the most vulnerable. A sampling of sea-bottom life common to local waters:

Eccentric sand dollars: Five “petals” on top are where breathing tubes emerge from shell.

Hermit crab: Has no shell, instead uses empty snail shells for protection.

Queenfish: Often the most common catch by pier anglers.

Dwarf brittle star: This creature can emit light from its body.

Northern anchovy: Commercially caught and important food for other fish, birds, mammals.

California halibut: Popular commercial and sport fish, with eyes on top side of body.

Sources: “Seawater Desalination in California,” California Coastal Commission; “Economic and Environmental Considerations of Seawater Desalination in California,” General Atomics; “Ocean to Faucet,” California Coast and Ocean; Metropolitan Water District; Municipal Water District of Orange County; International Desalination Assn.; Orange Coast College Prof. Dennis Kelley; “Pacific Intertidal Life”; Audubon’s “Pacific Coast”; “Marine Sportfish Identification.”

Researched By DANNY SULLIVAN and MARLA CONE / Los Angeles Times