California Looks To the Sea For a Drink of Water

HughPickens.com writes Justin Gillis writes in the NYT that as drought strikes California, residents can't help noticing the substantial reservoir of untapped water lapping at their shores — 187 quintillion gallons of it, more or less, shimmering invitingly in the sun. Once dismissed as too expensive and harmful to the environment desalination is getting a second look. A $1 billion desalination plant to supply booming San Diego County is under construction and due to open as early as November, providing a major test of whether California cities will be able to resort to the ocean to solve their water woes. "It was not an easy decision to build this plant," says Mark Weston, chairman of the agency that supplies water to towns in San Diego County. "But it is turning out to be a spectacular choice. What we thought was on the expensive side 10 years ago is now affordable."

Carlsbad's product will sell for around $2,000 per acre-foot (the amount used by two five-person U.S. households per year), which is 80 percent more than the county pays for treated water from outside the area. Water bills already average about $75 a month and the new plant will drive them up by $5 or so to secure a new supply equal to about 7 or 8 percent of the county's water consumption. Critics say the plant will use a huge amount of electricity, increasing the carbon dioxide emissions that cause global warming, which further strains water supplies. And local environmental groups, which fought the plant, fear a substantial impact on sea life. "There is just a lot more that can be done on both the conservation side and the water-recycling side before you get to [desalination]," says Rick Wilson, coastal management coordinator with the environmental group Surfrider Foundation. "We feel, in a lot of cases, that we haven't really explored all of those options."

Comments

But not to Nestle.

[140Mandak262Jamuna]

Nestle has been bottling the California water, which it takes at some abysmally low cost and ships it out. May be it would be cheaper for California to just buy the entire output of Nestle at market prices than to embark on this desalination process.

Re:But not to Nestle.

[Rei]

Agriculture is the big culprit, taking 80% of the state's water (and in return ag and mining together only make up 2% of the economy). Its a totally unsustainable situation that has to be remedied sooner or later.

That said, I do have hope for the future of desalination. Not with current techs (as with the one in the article, they're energy hungry and expensive), but potentially with new techs that don't rely on electricity as their power source. One I find interesting is this one. Basically, it relies on evaporation, which isn't unique... but *not* by capturing the evaporated water. It's just concentrated salt solution that's desired, which means that you don't need some sort of elaborate vapor capture system and sealed tanks, just simply any sort of open area that can hold water - even an endoherric basin or jettied-off chunk of ocean. Far, far cheaper.

Concentrated brine is turned into freshwater via ion bridges: it's connected to two tanks of normal seawater, one by a positive ion bridge and the other by a negative ion bridge. The brine greatly wants to dilute into the normal seawater, but it can't because the ions would be imbalanced in the two side tanks. So these two side tanks are connected to a third tank of seawater with the opposite ion bridges, so that salt can dilute from the brine into the two seawater tanks, but only if they also "suck" the opposite ion out of the final seawater tank. Since the brine concentrated brine wants to dilute so much, the action is energetically favorable and continues until there's no salt left in the third tank - aka, it's freshwater. (An actual implementation would be a continuous process, not fixed tanks, of course)

Apart from basic pumping needs, there's no electricity needed. The energy source is just "sun falling on any water chunk of seawater that's not free to circulate with the open ocean". You might even be able to have it filled automatically in some places via the tides or waves breaking over a jetty without having to pump new seawater in, leaving the only pumping needs for distribution.

Of course, the main tech limitation right now is making the salt bridges have high enough throughput and reliability to justify the capital costs.

Re:But not to Nestle.

[phantomfive]

California residents use about 1 trillion gallons a year (about 10% of California's yearly water usage). To put that into perspective: almond farms use about 1.2 trillion gallons a year; alfalfa farms use about 1.5 trillion gallons a year.

Not the past few years......farmers have been getting 50% (or less) of their normal amount of water. This year, for example, an almond farmer near Manteca who is used to getting 48 inches a year will be lucky to get 18 inches.

Re:But not to Nestle.

[mspohr]

"A hundred billion gallons of water per year is being exported in the form of alfalfa from California," Robert Glennon, a professor at the James E. Rogers College of Law at the University of Arizona, told the BBC, which claims it's now cheaper to send alfalfa from Los Angeles to Beijing via ship than to truck it from the Imperial Valley to the Central Valley."

http://www.bbc.com/news/magazi...

Re:But not to Nestle.

[ShanghaiBill]

The high cost of desalination is for the current reverse osmosis process, which requires high pressure to force the water through separation membranes. Now that graphene manufacturing is starting up (watch for the brand name Perforene), the cost of desal will fall off a cliff.

The high pressure is not because of the membrane resistance, but because of the osmotic pressure. That is not going away, unless some fundamental physical laws are repealed, including the first and second laws of thermodynamics. Better membranes can make a small difference, but not much. Also, for some weird reason, oceans tend to be located in low lying areas, so you need to factor in the cost of pumping the water uphill to the users. Pumping water already uses 10% of all the electricity generated in California.

Re:But not to Nestle.

[toadlife]

You're not counting groundwater. Nut crops are so profitable that farmers can afford to drill million dollar wells to make up for their lack of surface water allocations and still make money.

California's groundwater is completely unregulated and at this moment, and our aquifers, which take thousands of years to build up, are being irreparably damaged.

Re:Lifestyle

[alen]

in america we are expected to shower daily

Re: Lifestyle

[Anonymous Coward]

Just 20% of water usage in California comes from residents and non-ag businesses. 80% of water usage comes from agriculture. Almonds alone (70% of which are exported out of the country) account for about the same amount of water as all residences in the state.

People could switch to a two-minute shower once a week and it wouldn't make a measurable difference. Flood irrigation in a desert is the real problem, and until that's universally recognized, nothing will be solved.

If you retrofitted all almond groves to use drip irrigation, you could maintain the same crop output at less than half the water usage. Why not? Because it costs money, and growers would rather just pull more from their wells. The aquifers in California are a true Tragedy of the Commons.

What about Poo?

[Anonymous Coward]

Seriously, desalination is hard. Much harder than just completely cleaning and treating all waste water. That is why Singapore switched their desalination plant to poo processing. Getting rid of salt is incredibly hard.

Re:Energy use

[silas_moeckel]

They should not be using electricity in the first place. Desalination is a perfect pairing for cogeneration with Gen IV fission plants. Added benefit is you can put the entire output to desalination when demand is low to avoid using peeking plants.

Re:Energy use

[Applehu Akbar]

Desalination is an ideal use for fluctuating power sources in general. Instead of spending trillions to put wind and sun on the grid, use them to provide water for California and Texas. At the same time, we won't be using energy-intensive R-O forever. Cheaper desalination tech improves the equation.

Re:The obvious answer

[DrXym]

Who winds up paying for that?

All those pretentious hipsters who created the heightened demand for almonds in the first place because dairy / wheat is oh-so bad (it isn't).

Re:Lifestyle

[trout007]

It's always cheaper to save water or save energy,.

That's not true at all. There are diminishing returns.

Re: Lifestyle

[TheGavster]

I think that the 70% export figure indicates that while "other countries" have switched which crops they grow, they haven't changed their almond consumption rate. Similar to how the western world has eliminated the environmentally destructive extraction techniques necessary for rare earth metals, but still buys cell phones because China is willing to take the hit.

Re:I think we just need to get burned.

[Bing Tsher E]

Who is this 'we' and 'us' you refer to? I've been pumping excess flood water off my land all weekend. I have a 2" pump and it's working hard to keep a corner of my property dry, what with all the rain.

The county I live in used to be a huge supplier of tomatoes to the whole eastern half of the country, but now all I have around me is cornfields, presumably because of the artificial increase in corn prices that 'environmentalists' spurred with alcohol-as-a-fuel initiatives.

Whatever the political incentives there are that caused so much arid land in California to be converted to farmland (there are certainly said political factors at play- there always are) should be reviewed and removed. It doesn't make sense to grow crops in a desert if the real market forces at play would make it impossible if the water costs for farmers weren't distorted by politics.

Re:Lifestyle

[Bing Tsher E]

You say that like it's a good thing.

Do you know what the end result is of making sure you flush off all the oils and body waxes that our bodies have evolved to emit to protect our skin and organs from invasive organisms?

It's fairly similar to the process where the growth medium is 'sterilized' when you prepare petri dishes to grow cell cultures. A 'squeaky' clean body is a body 'shrieking' in terror, to put it succinctly.

Fuck you, soap and cosmetic companies. There is a balance to be arrived at, and the symbiotic organisms on and in our bodies are not our enemies, no matter how much of a profit you make by scaring people into buying your chemical products.

Re:I think we just need to get burned.

[n3r0.m4dski11z]

"presumably because of the artificial increase in corn prices that 'environmentalists' spurred with alcohol-as-a-fuel initiatives."

I dont disagree with most of your post, but two things about this statement are wrong. One, if you remember your history of the last 40 years, corn turning into alcohol was a problem that BUSH (not an environmentalist) pushed as a political solution to foreign oil. Not to mention that because "corn must go in everything", the US produced way more corn than it could ever use. Those two reasons are why corn is turned into ethanol in the usa. You may want to look into the history of big business and sugarcane as well in the USA. There are a few reasons that americans produce much corn*, but predominantly because it is cheaper;

"The use of HFCS in the United States is partially attributable to government tariffs that maintain domestic sugar prices at above the global price and subsidies to corn growers that lower the cost of the primary ingredient in HFCS, corn."

https://en.wikipedia.org/wiki/...

9 out of 10 environmentalists you meet I am sure will tell you that they absolutely do not want food being turned into fuel for cars. They want to reduce peoples dependance on cars and that involves using LESS fuel, not more. Do you know any "environmentalists" at all?

*( the paranoid part of me thinks that the government wants you to eat more corn sugar so that you will get fatter. Fat people dont start revolutions )

Re:I think we just need to get burned.

[RubberDogBone]

Well that is the unspoken elephant in the room: we have people trying to live in arid areas never before used for habitation, and we have farmers and ranchers trying to make a go of their businesses in areas never before suitable for that kind of thing, all thanks to supplied sources of water which are now dwindling.

The simple answer is that all these people should pack up and leave, Nobody is promised they can live in any particular place. And some places are just not meant for it. But people hate to do that. They'd rather fight and protest and pay lots of money to truck in water, etc. And struggle for years trying to make it work.