Marin thirsty for desalination Officials say tapping bay could solve water woes

San Francisco Chronicle ^ | Monday, December 30, 2002 | Peter Fimrite

[ckilmer]

With an uncertain water supply and memories of a near disastrous drought, Marin County's water lords are looking into an idea as old as Aristotle -- tapping the sea.

Heeding the pleas of environmentalists, the Marin Municipal Water District is studying a proposal to desalt the waters of San Pablo Bay and provide 5 million to 10 million gallons of drinking water a day, enough to serve as many as 30,000 homes a year.

[ckilmer]

Israeli firm to build desalination plants in Carribean and Australia

By Amiram Cohen

An Israeli company, Advanced Desalination Technologies (ADT), will set up prototype desalination plants in the Carribean, Australia and Israel during the course of next year. The plants will employ a new technology that could cut the cost of desalination by 50 percent.

Professor Avi Efrati, who developed the new technology, believes that commercial application of the technology could lower desalination costs from 50-55 cents per cubic meter to 22-25 cents per cubic meter for sea water and from 30-40 cents per cubic meter to 15-20 cents per cubic meter for salty ground water.

Efrati's technology is based on the use of commercial components that are currently used in a desalination process known as reverse osmosis. Instead of continuous flow desalination, Efrati's method uses a closed circuit with fixed or variable pressure.

Efrati claims that his new method will also lower the cost of building desalination facilities by half and will cut running costs by some 30 percent.

Efrati's technology has been the subject of interest of water companies overseas and is also being examined by the Mekorot national water utility. Ha'aretz has learned that Mekorot is planning to set up a prototype plant to examine the technology and two multinational desalination companies have expressed an interest in integrating the technology into their existing plants.

Professor Efrati said yesterday that commercial desalination plants with an output of 3000 cubic meters a day would be available within two years.

[My2Cents]

Water from the Bay? Good. Let folks in Marin drink their own sewage.

[Cicero]

Reverse osmosis has the advantage that it uses less power than distillation--but still presumably some power. I'd be curious about the power requirements of the new Israeli process.

The problem for California is that the environmental extremists want to have their cake and eat it too. And the power and water shortages are now intertwined.

[expatpat]

Desalted seawater is really a prominent source of water only in places like the Arabian Peninsula, where alternatives are all but nonexistent.

And where energy is really cheap.

The Marin eco-types like Huffman will add further to the costs of living in Californistan and the stress on electic power. But that's their problem, since I live on the E. Coast. Perhaps the wider use of desalination will bring costs down, but the energy-intensivity makes me skeptical.

[dtel]

I am surprised this technology has not been in use for decades already.
One of the bigger mistakes of our times, IMO.

[krb]

One of the bigger mistakes of our times, IMO.

The big mistake is crowding people into areas that don't naturally support that many people.

[Clara Lou]

Question: Withdrawing all of those millions of gallons of water from the bay daily will have what environmental effects on the bay? Is that another can of worms or not a problem?

[IncPen]

I would think a Nuclear powered de-sal plant would neatly solve all the problems, but then I'm not an enviromentalist wacko, either...

[crystalk]

In California they always wait until they are in a real fix before thinking of anything. Florida, which has four times the rain water per square mile of California, has several major desal projects going in the southwest part of the state IIUC.

[ckilmer]

I am surprised this technology has not been in use for decades already.
One of the bigger mistakes of our times, IMO.
////////////////////////
the reason the technology hasn't been in use for decades is that the price has been prohibitively high and the demand wasn't that great.

Now prices are falling as demand increases.

To get perspective on this. The cost of fresh water on the east coast of the USA runs about $25-50@acre foot. Desalination 5-6 years ago cost about $2000@ acre foot. Now desalination costs about $600@acre foot. The israelis have a way to do it for $300@acre foot.

Water for southern california currently runs about $250@acre foot.

If prices for water desalination continue to fall for the next 10--15 years at the same rate as they have for the last 5-6 years then desalinised sea water will cost the same as water on the east coast.

If you look at precipitation map of the world, you'll notice that most of the world's deserts are right beside the ocean.

Very big things start to happen when the cost of water desalination falls far enough. The biggest thing is that the 21st century civilization becomes very plausible indeed.

[pbear8]

The average depth of the Bay is only about 14 feet now, where am I supposed to sail when the Marinites drink up the Bay?

[citizen]

Cool! Life in the PRK:

Rolling blackouts & dry faucets. Take your choice - Air-Conditioning or bathing water?

[dtel]

How much money has been spent damming rivers, building lakes, rtc, that has kept the price of water relatively low?
If the money spent on the aquaduct to So. Cal, had been spent on a renewable resource like desalinazation, and I would think some kind of power generation/desal plant would be one way to maximize resources, the price could have been competetive long ago.
I am probably just blue-skying it here, as there must be myriad reasons other options were pursued.

[elbucko]

I am surprised this technology has not been in use for decades already.

It has been used for decades, on nuclear powered aircraft carriers and submarines. The marriage of nuclear power and salt water de-salination is a natural. But the Luddites of the "Green" movement see it as a deal with the devil. Too bad.

[expatpat]

Because it's too expensive.

[expatpat]

I'd suspect it's not a real problem, since any water taken out of the Bay would be immediately replaced by seawater from the Pacific.

[dtel]

"Because it's too expensive."

If we had spent the time and resources perfecting this technology over the last 40 years, we spent building dams and other geegaws, especially in the drought ridden West, there would be no fresh water crises looming in CA.
As elbucko, points out above, we have been using this technology on our ships and subs for decades.
A combination nuclear power/desal plant would be able to sell two resources, fresh water/electricity, off one unusable resource, saltwater.
Short-sightedness/NIMBYism, once again rears its ugly head.

[expatpat]

The problem is that it uses a lot of energy. Some (10-20%) reductions are possible, perhaps, with more engineering but the 'science' of pumps and heat-exchangers is well-established.

Quoting DoD's use on a small scale is not relevant; the military is willing to spend a lot more on meeting their mission than civilians are for everyday use.

[expatpat]

For now, anyway.

I agree that the opposition to nuclear power is a mistake; it's stupid to fret about CO2 emissions and reject nuclear at the same time.

The eco-idiots worry about nuclear waste disposal. Where did it come from in the first place? Out of the ground; just put it back in old uranium/plutonium mines. The oceans can handle it easily, also.

[robertpaulsen]

Why do they need so much salt? Can't they just truck it in? Wouldn't that be cheaper?