Desalting Plant Opens Amid Surplus : Resources: Santa Barbara plans to use about 25% of the $30-million project’s capacity. The expense of desalinating seawater and the recent rains have city officials defending their decision.
Only a year ago, residents here painted their grass green, passed up showers and complained to city leaders for having allowed water supplies to become critically low. In response, those officials this Friday will crank up the largest and costliest municipal seawater desalination plant outside the Middle East and begin wringing fresh water from the sea.
But while the $30-million project is being counted on to make drought-proof what has been among the driest areas along the Pacific Coast, the city now plans to use only a quarter of the plant’s capacity, or less.
Santa Barbara’s ironic transition from shortage to surplus is being closely watched by other communities as the city gets whipsawed by a long-term drought interrupted by occasional heavy rains.
When faced last summer with one reservoir that had gone dry and projections that the area’s largest reservoir would turn to dust by this spring, this community rushed to build the emergency desalination plant in nine months.
Other cities along the California coast--or even those threatened by drastic reductions of state water because of the drought--kept track as the system of filters and pipes took shape. Some local agencies viewed the Santa Barbara plant as a model for facilities they perhaps should be building.
Then came this month’s rains and Santa Barbara County and the rest of Southern California were deluged by 10 of the wettest days on record.
Now, with the city-owned Gibraltar Reservoir spilling over and the area’s main source of water at Lake Cachuma nearing 75% of capacity, Santa Barbara’s outlook has been transformed. The city’s leaders now face questions on the prudence of spending public money for the plant.
Santa Barbara Mayor Sheila Lodge defended the city’s decision to move ahead with desalination while other communities were studying their options.
“I’m glad we’ve got it built,” Lodge said. “The dry cycle will come back again, and when it does, we will be prepared. It is our insurance policy against drought.”
She pointed to the emergency that Santa Barbara faced last year--the residents had already cut water use by 45%, and community leaders felt that they could not squeeze any more.
“Cutting use by 50% is more than conservation,” said Sandra Lizarraga, deputy city administrator. “That is personal sacrifice.”
Still, such critics of the desalination project as Peter Schillke say the city should have invested in permanent conservation, such as offering cash to help residents replace lawns with drought-tolerant gardens rather than spend money on new technology that may never be used. The city did offer free low-flow toilets and shower heads, he said, but it should have required homeowners to install them.
“The desalination plant made poor economic sense and it made poor ecological sense,” said Schillke, a mechanical engineer.
The cost of desalinated water to the city is estimated at $1,900 an acre-foot, which includes construction costs and operating expenses. By comparison, federally subsidized water from Lake Cachuma, S. Bureau of Reclamation project built more than 30 years ago, costs the city $230 an acre-foot, treated and delivered.
The city intends to pay back the $30-million capital costs of the plant over the next five years with revenue from the city’s water users. But officials say they will be able to make the payments without additional increases in water rates, which have skyrocketed by 300% since 1989, when the city implemented a tiered-rate system.
Lizarraga said that average monthly water bills of about $20 before rate increases in 1989 have not increased for 70% of residents because they reduced their water use. However, she said, if residents take advantage of the new supplies and begin using the same amount of water they used in 1989, their monthly bills would triple to about $60.
And it is that projected new revenue from increased use that the city intends to use to pay off the bulk of its desalination plant debt. That way, Lizarraga said, those who use the most water will bear most of the cost of the desalination plant.
“As usage approaches normal, we feel the plant will pay for itself,” Lizarraga said.
But because the city’s water from Lake Cachuma and other sources is much cheaper, the desalinated water will be used only as a sort of last resort.
“We don’t see needing it very much,” she said. “The highest scenario is that we would use 5,000 acre-feet and the lowest scenario is that we would use zero. But we will start at 2,500 and adjust it up or down as needed.”
Lizarraga said the city also will recoup some of its investment by selling a small amount of desalinated water to neighboring Montecito and Goleta.
The state’s chief hydrologist, Maurice Roos, said he believes that water from Northern California delivered by the state’s aqueduct is still the most reliable water source and the best bargain for the coastal cities. Santa Barbara had refused this option in the past because of concerns that imported water would induce too much urban growth.
The state is ready to begin building a $320-million pipeline to connect Santa Barbara and San Luis Obispo to the state’s aqueduct as soon as the cities are ready to pay for it, Roos said. Officials said the cost for the state water would be about $500 an acre-foot. (Water engineers calculate that an acre-foot is enough to serve a family of five for 18 months.)
Although the state system has been under severe strain, Roos said the cities and water agencies it serves received their full demands during the early drought years of 1987, 1988 and 1989. In 1990, the state filled full requests for urban users but cut deliveries to agricultural users. “All that time, Santa Barbara could have been using state water and saving their local resources,” Roos said. “That would have lightened the load considerably last year.”
Santa Barbara opted to begin with desalination first because a plant could be up and running within the year, and it would take about five years to connect to the state system.
Santa Barbara and its consultants worked through a year of environmental studies and permit applications and broke ground on the desalination plant on 1.2 acres of city-owned property near the beach last May. The next month, residents in a citywide referendum ratified by an 82% “yes” vote their leaders’ decision to build the emergency facility. In the same referendum, voters said they wanted eventually to make state water a part of the city’s long-term water supply plan.
Desalination was hardly new technology to California voters. Over the last several years, nine offshore oil platforms, a pair of power plants and one oil and gas processing plant along the coast have built small desalination plants to fill their drinking water needs.
Last October, Catalina Island’s Avalon became the first city in the state with a municipal desalination plant, but the facility is a fraction of the size of Santa Barbara’s plant and the industrial units are smaller.
Coastal communities, including Marin and San Diego counties and the cities of Morro Bay, San Luis Obispo and Oxnard, have been considering seawater desalination plants to supplement supplies.
Morro Bay began building its plant without state permits and is being opposed by the California Coastal Commission.
But Santa Barbara’s plant, which is designed to draw in nearly 20,000 acre-feet of ocean water a year in order to produce 10,000 acre-feet of fresh water, is by far the largest municipal facility built or planned in the state.
Ionics Inc., an American-owned company that has developed desalting technology worldwide, built the Santa Barbara plant and fronted the cash to fund construction. The city plans to pay Ionics back over five years, allowing it to move ahead with emergency plans during tough economic times.
Ionics, which operates plants in the Canary Islands and in Florida, also paid for extensive studies to examine the effects of the desalination plant on the area and ocean environment.
“This is a project where there are no environmental trade-offs,” said Ron Sherer, district engineer for the Central Coast Regional Water Quality Control Board, which oversees all waste-water discharges.
Massive amounts of electricity are needed to force seawater through very fine membranes at extremely high pressure in order to filter out the salt molecules. However, Richard Ferguson, a physicist who serves as a Sierra Club energy expert, said it will take almost as much energy to pump state water to Santa Barbara.
“It’s a decision between two choices which are both very energy dependent,” he said. “The fear is if they import water or augment the supply, people will go back to using water wastefully.”
But Lodge insisted that conservation can only be one part of the equation for Santa Barbara.
“We’ve known all along we needed another source of water for the dry years,” she said. “And desalination is the only source that is not dependent on rain.”
Getting Water from the Sea
Santa Barbara’s new desalination plant has the capacity to produce 10,000 acre feet of fresh water a year, but will begin operating later this month at 3,750 acre-feet per year. For every 10 million gallons of water that comes into the plant, 4.5 million gallons will become fresh drinking water for Santa Barbara.
A) Sea water is pulled into a pipeline 30 feet under water that extends 2,500 feet from shore. Powerful pumps draw in 16,000 gallons a minute (at the plant’s full capacity).
B) Booster pumps at an interim station add pressure to the water, forcing it through three sets of filters that become progressively finer. The filters strain out silt and other particles such as dirt and kelp.
C) The water is then forced at extremely high pressure through a series of very fine membranes inside fiberglass tubes. The pressure forces the water molecules through the membranes while the salt molecules stay behind, a process called reverse osmosis. The remaining brine is mixed with treated waste water and discharged to the sea.