Bay Area looks to draw water straight from the Bay
By: John Upton
Examiner Staff Writer
January 15, 2009
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| FRESHEN UP: The San Francisco Public Utilities Commission and other water districts hope to be able to provide drinking water to Bay Area residents through desalination — a process that converts salty water into fresh drinking water. (Getty Images file photo) |
SAN FRANCISCO — A long-running plan to keep millions of Bay Area residents with drinkable water during a water crisis such as a drought or disaster by desalting sea and river water is coming up against funding obstacles due to California’s budget crisis.
San Franciscans enjoy some of California’s cleanest water — fresh snowmelt that gushes through a labyrinth of pipes from the Sierra Mountains down to The City. But San Francisco’slong distance from its dams leaves its water supply vulnerable to earthquakes, and its reliance on snowmelt leaves its thirst at the mercy of the warming globe, which is reducing snowpacks.
In October, the San Francisco Public Utilities Commission and three other local water agenciesbegan a $2 million desalination experiment in the East Bay to see whether they could affordably remove enough salt from brackish estuaries or from the sea to provide emergency drinking water to their 5 million water customers.
Desalination turns salty water into fresh drinking water. In desalination plants, the water is forced at high pressure through a filter, known as a membrane, through which water molecules can pass but salt cannot.
In the Bay Area, desalination efforts are under way next to an estuary in Bay Point, where a $2 million, six-month pilot project was started in October by the San Francisco Public Utilities Commission and three other local water agencies.
The first round of experiments at the pilot plant concluded in December.
“The very preliminary results show that it’s working,” said Hasan Abdullah, desalination coordinator at the East Bay Municipal Utility District, one of San Francisco’s partners in the project. “I’d be surprised if we find that it doesn’t achieve our water quality goals.”
One of the purposes of the pilot project is to test different membranes to see how well they filter salt out of brackish Delta water, where salinity levels fluctuate massively by the hour, season and year, according to project manager Mari Valmores of the Contra Costa Water District, which is overseeing the experiment in eastern Contra Costa County.
The pilot project is being funded with $1 million in grants from the California Department of Water Resources, and with $250,000 apiece in cash or in-kind services from each of the participating local agencies.
Desalination plants have been used in rain-poor, energy-rich countries in the Middle East for decades, according to John MacHarg, founder of Affordable Desalination Collaboration, an industry group representing desalination companies.
Within the last decade, the technology has been improving and spreading worldwide as demand for freshwater has been growing, according to MacHarg.
New desalination efforts are under way or under investigation around the world, including in Australia, Algeria, China and Singapore, and in a growing number of California cities and counties, including San Diego, Marin, Santa Cruz and Santa Barbara, according to MacHarg.
But uncertainty about California’s chronic budget deficit is clouding the future of public works projects, which could include desalination projects, according to California Department of Water Resources spokesman Don Strickland.
“The state’s Pooled Money Investment Board voted to freeze certain disbursements, and this could potentially include grant funds for water desalination projects,” Strickland said in an e-mail. “It may be necessary to temporarily suspend payments.”
If funding for the desalination project from California evaporates, the San Francisco Public Utilities Commission hopes the agencies can secure funding under the economic stimulus plan championed by President-elect Barack Obama, according to Michael Carlin, General Manager of SFPUC Water Enterprise.
If the pilot project is successful, the SFPUC could build a desalination plant by itself or, preferably, in conjunction with other local agencies by 2012, according to Carlin. Sites being considered are inside and outside of The City, where salty water would be harvested from the ocean, Bay or Delta.
The plant, once built, would operate slowly around-the-clock to ensure that it’s ready to be quickly used in a crisis, according to Carlin.
The proposed plant would desalt 65 million gallons of water per day and cost up to $400 millionto build and up to $47 million a year to operate,SFPUC figures show. Results from the pilot project will help refine those cost estimates.
Although the water produced by the plant wouldn’t taste as good as snowmelt, it would be safe to drink, according to Carlin.
Mobile unit will dispense water during emergency
When an earthquake or other disaster wreaks havoc with San Francisco’s water supply, The City’s water agency will be ready with a $500,000 mobile water treatment and bagging machine to ensure a drinkable water supply.
The San Francisco Public Utilities Commission bought the trailer-mounted emergency water distribution unit last year using U.S. Department of Homeland Security funds, according to SFPUC water manager Michael Carlin.
“We can hook it up to a water source and start bagging water in tough plastic bags,” Carlin said. “Then we can hand them out just like bottled water.”
The unit can draw water out of water hydrants or from reservoirs, such as Lake Merced, and it’s equipped with ozone- and ultraviolet-light-based disinfecting equipment that can be powered using a back-up generator, agency documents show.
— John Upton
Sites identified as possible plant locations
The Bay Area’s four largest water agencies are jointly exploring a regional desalination project that would provide an additional water source for the region:
Contra Costa Water District
East Bay Municipal Utility District
San Francisco Public Utilities Commission
Santa Clara Valley Water District
Breaking down the Bay Area project
According to officials, if the pilot project is successful, the San Francisco Public Utilities Commission hopes to build a desalination plant by 2012.
$234 million to $400 million Estimated cost to build a permanent desalination plant*
71 million gallons Ultimate possible capacity per day from the project’s desalination facilities
$25 million to $47.5 million Estimated annual cost to operate and maintain the plant*
5.4 million Residents and businesses that could be served by desalination project
$1,237 to $2,994 Estimated cost to desalt one acre-foot of water — 325,000 gallons — at the plants
$2 million Cost of a desalination pilot project in Bay Point
