Monterey Bay is home to a dazzling array of marine life—from giant octopus to jellyfish. But on land, water is growing scarce. Facing diminishing fresh water supplies, residents are considering an option more common to desert countries like Saudi Arabia: desalination. If water officials and Cal-American Water have their way, the largest marine sanctuary in California may also become home to some of the state’s biggest desalination plants—and it won’t be alone. At least two dozen proposals for plants sit before local water boards and other regulatory agencies like the California Coastal Commission.
If approved, the new projects would signal a major shift in the state’s water policy. California now has nine low-capacity desalination plants, producing 3,100 acre-feet (AF) of desalted seawater annually. Less than a third is for household use, with the rest going to industrial applications. The current proposals would produce a whopping 220,000 AF per year, with all but 335 AF slotted for homes. (A household typically consumes one acre-foot per year.)
Some of the larger plants are proposed for Southern California, where the water business has always been lucrative. Controversial projects in Huntington Beach and Carlsbad would be the largest in the nation. But the bulk of the proposals target the 250-mile long Monterey Bay National Marine Sanctuary—ten in all. Together, they would produce about 15,000 AF of desalted seawater a year (or 13 million gallons daily), releasing roughly the same amount in high-salinity brine byproduct back into the sanctuary. The two largest are for the Monterey Peninsula; the other eight combined add up to under 5,000 AF.
Historically, desalination has been seen as prohibitively expensive, inefficient, and a little off the wall, but technological advances have made it increasingly affordable. Elaborate membranes and filters have been redesigned to work better and last twice as long, while other breakthroughs have made the process more energy-efficient. The process is looking more feasible to municipalities and water companies up and down the coast.
The Monterey Peninsula Water District has long struggled with insufficient sources of fresh water. Cal-American, the multinational that supplies the district’s water, has been diverting 66 percent more water than legally allotted from the Carmel River. After the state ordered the company to get a new water source, Cal-American and the Water District’s board filed competing applications for two different 10,000 AF desalination plants. Only one can be approved. Desalination is one way the town can guarantee a steady water source, says Kris Lindstrom of Monterey’s water board. “It’s going to be more expensive, but it will be under local control, in the public hands. If there’s a drought, people won’t have to sacrifice their gardens.”
But in an area like Monterey Bay, where growth has been capped by water scarcity, the idea of a “limitless” water supply creates its own controversy. And in places like Orange County, where growth has been largely unfettered, some wonder where it will stop. The Coastal Commission requires that desalination plants meet current needs only. But a plant’s capacity is easily expanded. “The fundamental problem with desalting the ocean is that it’s growth-inducing,” says Mark Massarra, of the Sierra Club’s Coastal Program.
In addition to fears of increased development and high energy demand, concerns have been raised about environmental impacts of desalination. Due to lack of experience with high-capacity plants, officials are unwilling to speculate on the environmental effects. Depending on the design, risks could range from destruction of the seabed to localized increase in water temperature and salinity. The disturbance of endangered species onshore is also possible.
“One of the problems with coastal desal plants is what they suck in and what they do with what comes out,” says the Sierra Club’s Dan Sullivan. When a plant pumps in seawater for treatment, the water runs through a series of grates and filters, trapping and killing organisms of all sizes. While some low-capacity plants have managed to decrease entrapment by burying their intake pipes under the seabed, no one’s figured out how to design larger capacity intake systems that won’t harm fish, marine larvae, and other organisms. The EPA estimates that trillions of ocean organisms are lost around the country each year to water-cooled power plants’ intake systems, which are similar to those of desalination plants.
Desalination also has an unwelcome byproduct—brine, a concentrate of salt, other minerals, and organic material. As part of the process, brine is pumped back into the sea. Anywhere from 1.5 to 3 times as salty as ambient seawater, brine is heavier and therefore difficult to diffuse into the ocean. With a constant feed, the outfall can create a plume of high salinity water that sits offshore, which may contribute to the growth of harmful algae blooms like red tide.
The plant Cal-American has proposed to serve the Monterey Peninsula would sit alongside California’s largest power plant at Moss Landing. The practice of siting desal facilities together with existing power plants, known as “co-location,” is widespread. Cal-American would tap Duke Energy’s massive cooling water supply, desalinate it with reverse osmosis, and send the brine byproduct back into the sea with wastewater from the plant’s cooling system. Some see this as encouraging an already destructive system. “Co-location is a method of artificially extending the lifespan of antiquated coastal power plants using once-through cooling, which is extremely destructive to marine life,” says Massarra.
While planners believe it easier to get co-located facilities approved, this may not be true for the Moss Landing proposal. The plant’s intake and outtake pipes jut into the mouth of Elkhorn Slough, at the apex of protected Monterey Submarine Canyon, home to many creatures, from delicate marine larvae to sharks and otters, that depend on minute shifts in salinity to survive in the slough.
Despite challenges to building an environmentally sound facility for the Monterey Peninsula, either at Moss Landing or elsewhere in the district, Lindstrom remains positive about the possibilities for desalination. “When it’s done right, we won’t be impacting the marine environment,” he says. “Getting an environmentally acceptable site, a subsurface system, and brine disposal that doesn’t damage the environment, these are pretty much the same issues with any desal plant. It’s not going to be easy, but if we get through it, it will be monumental.”
Of the projects proposed statewide, at least six are to be privately run, which raises concerns about corporate control of municipal water supplies. Once private companies take charge, critics warn, it’s a short leap to undermining community control of water and the environment. International trade agreements like GATT and NAFTA can protect privately owned desal plants from local and state environmental regulations the Coastal Commission is working hard to establish. “GATS, GATT, NAFTA and other so-called ‘free-trade’ agreements could end up being the tail that wags the planning dog,” says Massarra. “Or worse, they could nullify the Coastal Act and other California planning and environmental laws.”
Proposals will be reviewed on a case-by-case basis by the Coastal Commission, as well as at least 16 other regional, state, and federal agencies. The commission is scurrying to draft an in-depth report exploring desalination and making recommendations to the state legislature on guidelines and regulations. The commission’s draft report outlines serious environmental impacts like loss of marine life, destruction of habitats, and inducement to sprawl. A public comment period for the report is open until November 7
