Scuba Diving club,
Southern California
Sea Sabres
California
taps ocean to shore up water supplies
New technology
better at removing salt from water
By Laura Wides
LOS
ANGELES – California's classic quest for water, made more pressing by a
persistent Western drought and a severe cutback in Colorado River supplies, is
turning to what many have regarded as an obvious source: the ocean that forms
the state's western border.
New
technology has made it cheaper to squeeze freshwater from the ocean while other
states' demand for more Colorado River has made it a near necessity.
"There's
only so much you can conserve," said Steven Erie, political science
professor and water expert at the University of California San Diego. "The
future is recycling and desalination."
The
Metropolitan Water District of Southern California, which serves 18 million
customers in six counties, is in the process of approving plans to subsidize
five desalination plants, proposals that were submitted by local water
agencies. Together, the plants could supply up to 7 percent of MWD's customers
by 2007.
MWD
tentatively approved the proposals in December and expects construction to
begin by 2005, pending environmental reviews.
"Even
though it only represents a small portion of the water we use, it's an
additional supply," MWD Board Chairman Phillip Pace said. "It's something everyone has an
interest in."
Elsewhere
in the nation, desalination is being considered as a way to supplement
dwindling groundwater supplies.
In
Florida, a Tampa Bay plant is scheduled to open this month, with a second one
in the works. Texas also is researching desalination sites, while landlocked
New Mexico wants to produce drinking water by wringing salt from its brackish,
underground aquifers.
Critics
said desalination remains too expensive, in large part because of the power
required to run the plants. They say the process damages local coastal
environments.
For
every two gallons of water filtered, one gallon of drinking water is produced.
The highly concentrated salt water known as brine goes back to the sea. In
heavy concentrations, that brine can kill small sea creatures, according to the
California Coastal Commission. Scientists
are still studying its effects on dolphins and other mammals.
"It's
always easier to seek new sources than to conserve," said Jane Kelly,
state director for the consumer group Public Citizen, which has long worked on
California water and conservation issues.
Supporters,
however, say desalination is a crucial part of California's search for new
water supplies.
The
state's population is expected to grow by 6 million by 2010, according to the
California Department of Finance. Supporters also note a federal order
requiring California to cut its use of the Colorado River to fulfill a
decades-old agreement with six other Western states.
The
Interior Department ordered the cutback when the state missed a Dec. 31
deadline to forge an agreement saying how it would reduce its overreliance on
river water. The deal fell apart when an Imperial Valley utility district
rejected it. A last-minute attempt to salvage the agreement failed.
Since
then, the Metropolitan Water District has said it has access to ample water
supplies for the next 20 years, even without the extra Colorado River water it
has received for decades.
"It's
expensive," the MWD's Pace said, referring to desalination. "But if
you have the difference between additional expense and no water,you go with
expense."
The
basic process of desalination is not new. Salt water is pumped through filters
under high pressure, squeezing out minerals. Israel and Kuwait have relied on
desalination for decades, as have military vessels and cruise ships.
More
than a dozen small plants were built along California's coast during the early
1990s when the state faced its last drought, but most were for industry. Nearly
all were shut down or dismantled because of high operating costs and because
water agencies found cheaper water elsewhere.
The
Coastal Commission must give final approval for most desalination proposals
along the state's 1,100-mile coastline and is finishing a study of existing and
potential sites.
According
to its study, only the city of Marina, north of the Monterey Peninsula, still
uses desalination to provide a portion of its domestic drinking water.
More
projects are in the works. The commission counted about 13 proposed domestic
desalination sites from Marin County to San Diego and another six that could be
reactivated.
In
November, California voters approved $50 million for desalination-plant
construction and research under Proposition 50. Gov. Gray Davis signed
legislation to study the process.
Support
for desalination comes partly from lowered costs. The process has become more
efficient in recent years by compacting filters, reducing energy use and
improving the treatment process.
Costs
also have been cut by proposing to combine the desalination process with
coastal power plants. The desalination plants would syphon off ocean water
already being used to cool the power plants.
Since
the late 1980s, the price of taking salt out of seawater has dropped from
nearly $2,000 an acre-foot to $800 per acre-foot, said Walter Winrow, vice
president of Poseidon Resources. The company built the Tampa Bay project and
has several proposals in Southern California.
MWD
currently sells water for nearly half that cost, but spokesman Adan Ortega said
the district would subsidize the price of desalinized water by $250 per
acre-foot for proposed plants in Carlsbad, Los Angeles, Long Beach, El Segundo
and Dana Point.
An
acre-foot is enough to cover an acre 1 foot deep. It typically would supply a
family's needs for a year.
Desalination
plants are likely to cost between $70 million and $300 million to build.
"It
is expensive, but it's not something of the other world anymore," Ortega
said.
Local
water agency officials said they had no immediate plans to charge extra for
desalinated water but added the price of water in California is likely to rise
no matter what new sources are used.
Desalination
will be only part of California's water plan even if it provides a significant
boost to supplies, supporters and critics said. Other alternatives include
recycling, increased storage and conservation.
Because
desalinated water is too expensive to pump more than several miles inland,
California's savings would come as coastal communities are weaned off the State
Water Project and the Colorado River.
Most
of California's population lives near the coast.
"Desalination
is getting off the ground," said Arthur Baggett Jr., chairman of the State
Water Resources Control Board. "It is part of the solution to sustainable
growth in California."
Copyright
2003 Union-Tribune Publishing Co.
Tampa
Open Largest US desalination plant
Posted April 8, 2003
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