"We would particularly look at where a plant is located," said Cy Oggins, a Coastal Commission staffer. "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 Metropolitan Water District would like to build by 1997--next to an undetermined power plant between Ventura and San Diego--would unload 40 million gallons of brine daily into the ocean.
Marine researchers say brine from even the largest desalting operation is a drop in the ocean compared to billions of gallons of urban runoff, power plant discharge and treated sewage that already flows daily into the Pacific from Southern California. A single power plant in one day releases up to half a billion gallons of hot water used to create steam and run generators.
"It's just a bump on a much bigger mountain range. A much more significant problem is surface runoff, which is toxic. With desalination, you're talking about adding brine, which is essentially salt," said Jeffrey Cross, director of the Southern California Coastal Water Research Project, a group of scientists assembled by local governments which studies the impact of ocean waste disposal on marine life.
Cross notes, however, that while he believes pumping it 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."
Some environmentalists say it is ludicrous to call the brine insignificant just because larger amounts of worse wastes are already dumped in the ocean. "Anything in great quantity is a potential problem," Sulnick said.
Gordon Hess, resources planning director at the San Diego County Water Authority, said engineers are performing computer modeling to see if a proposed 30-million-gallon-per-day desalting operation 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," Hess said. "One option we have is to haul the brine to a nearby salt company. But that is a partial solution, since it couldn't handle all of it."
The environmental challenges aren't necessarily insurmountable. In fact, modern engineering can probably resolve many of the threats.
The trick, however, is to protect the environment without inflicting an exorbitant price tag that would make desalting unaffordable. "It can be done. But it's the cost that's a concern," said David Dean, a mechanical engineer at Metropolitan.
To minimize the environmental impacts as well as the cost, most proposed desalting operations, including ones in Huntington Beach and San Diego Bay, would be paired with coastal electric plants. The brine could then be diluted with power plant discharges--bringing both closer in content to ocean waters before it is pumped out.
Teaming desalting operations with power plants also reduces energy needs, eliminates problems in purchasing beachfront land, and means no new intake and discharge pipelines would disrupt the ocean.
"It's far, far easier to amend an existing permit than to purchase virgin coastline. Our sites have already been used for industrial purposes," said Skowronski of Edison.
Dean said air pollution will be a major obstacle, since desalination requires large amounts of electricity, which in turn releases nitrogen oxides--a main ingredient in the Los Angeles basin's smog.
One solution is building the desalting operations at several power plants in Los Angeles County and Huntington Beach that already are mandated to install equipment that cuts air emissions by 90%. Even then, air-quality concerns remain because a power plant would have to operate at close to 100% of capacity--about five times more often than now.
Still, whenever harvesting more water, 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.
