The
Search For Drinking Water In California Has Led To The Ocean
California
is getting some much needed rain this week, but more than two-thirds
of the state is still in extreme drought conditions, and that has the
state thinking about alternative ways of getting water.
26
February, 2014
On
the coast in Carlsbad, Calif., construction workers are building what
will be the largest seawater desalination plant in the Western
Hemisphere. When finished in early 2016, it is expected to provide up
to 50 million gallons of fresh drinkable water every day.
"That's
enough water for 112,000 households here in the region," says
Peter MacLaggan with Poseidon Resources, the developer of this $1
billion plant.
The
process, MacLaggan explains, involves taking water from the Pacific
Ocean, removing the silt, sand and "organics," then
pressurizing the water through very fine membranes. The technical
name is reverse osmosis. And the result? "Every 2 gallons of
seawater that goes in, 1 gallon of high-quality drinking water comes
out," he says.
Images
of Folsom Lake, a reservoir in Northern California, show the severity
of the state's drought. The photo at left, taken on July 20, 2011,
show the lake at 97 percent of total capacity and 130 percent of its
historical average for that date. The photo at right shows the lake
on Jan. 16, 2014, when it was at 17 percent of capacity and 35
percent of its historical average.
"It's
droughtproof because it's not dependent on snowpack in the Sierras,
it's not dependent on rainfall here in San Diego," he says.
"You're getting water from the Pacific Ocean."
The
word "droughtproof" carries a lot of weight in California.
That snowpack in the Sierra Nevada he's talking about is still less
than half of what it should be for this time of year. Farmers,
environmentalists and cities like nearby San Diego have been fighting
over what little water there is.
"San
Diego currently imports about 70 percent of its water," says Bob
Yamada, the water resources manager at the San Diego County Water
Authority.
Yamada
says that's why the authority has agreed to buy water from the
Carlsbad plant when it's finished — even though it costs twice as
much as the water imported from Northern California and the Colorado
River.
It's
expensive "but it does provide you with the highest
reliability," Yamada says. And he says people are willing to pay
more for reliability. He also thinks that the difference in price
between imported water and desalinated will shrink as more and more
people vie for less and less water from rainfall and snowpack.
Desalination
costs more because it takes a lot of energy to suck 100 million
gallons of ocean water into a plant and pressurize it through little
tubes. And that's where the opposition comes in.
"Well,
on a macro level, we just think that there are less expensive, less
environmentally damaging ways to increase our water supply,"
says Rick Wilson with Surfrider Foundation. The nonprofit
environmental group opposes the Carlsbad project.
One
reason, Wilson says, is that all of that energy use will contribute
to global warming. More directly, he says, the intake pipe for the
plant will suck in sea life, killing marine animals.
"And
there's also the concern in some cases about the discharge from these
plants," he says. Discharge is the extra salty leftover water
that's pumped back into the ocean.
Those
concerns have stalled plans for another desalination site farther up
the coast, in Huntington Beach. Carlsbad though, has met all of the
state's requirements. Still, Wilson says, money would be better spent
on conservation and water recycling efforts.
Jeffrey
Kightlinger, the general manager of the Metropolitan Water District
of Southern California, says the district has invested in
conservation and recycling, and it has helped, but the region still
needs more water to meet demand. That's always been the case in arid
California, but it's even more so now.
"There
are two things that are changing the landscape for us," he says.
"One is we've grown a lot. We're doing water for nearly 40
million people statewide. The second thing that really changed is
climate change. It's real. And it's stressing our system in new
ways."
Kightlinger
says that means Californians have less time and flexibility to debate
different ways of getting water, storing it and moving it to areas
where it's needed.
"We
don't have time to rehash the same debates over and over and over
again. We're going to have to start investing in things for the
future," Kightlinger says.
He
says desalination helps, but it's not a cure-all. It's expensive, it
does take a lot of energy and it can treat only so much water at a
time.
His
agency gets about 30 percent of its water from Northern California
through the State Water Project. "To replace that supply would
require a Carlsbad plant every 4 miles between LA and San Diego,"
he says.
That
would be 25 plants in that stretch. Statewide, 17 desalination plants
are in some stage of planning on the California coast
$1 billion per 112,000 homes. Yeah, that makes a lot of cents. Only $357 billion more to go.
ReplyDeleteNo mention of agriculture - which uses a LOT more water.
Desalinization is extremely energy intensive.
This will not solve California water problems.