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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."
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."
Wouldn't help much. They bottle about 500 million gallons of water a year. 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.
Start whacking industries who use the most water with a levy to pay for the plants. e.g. almond growers. If they are suddenly motivated to develop ways to save water then fine, if then don't then it's still a new plant.
At first I thought that the 'Acre-Foot' sounded like a joke unit, but obviously it is the amount of water that one hundred and twelve horses need to drink if they are each to plough eight hundred furlongs of furrow in a fortnight!! Honestly, you Americans just crack me up with your wacky units. So much more fun than being stuck with boring old litres!
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.
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.
Trump's plan to get rid of Mueller appears to be 'be so guilty of so many things that Mueller works himself to death.'
San Diego has the cleanest power of anywhere in the whole US. They currently get over 25% of their power from renewable sources such as wind and solar and 67% from natural gas. They burn ZERO coal or oil. They are the model for the whole US.
Peter predicted that you would "deliberately forget" creation 2000 years ago...
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.
I generally support Nuclear power, but in reference to old plants shutting down? Good. Old reactor designs need to be retired, because quite frankly they're not safe enough compared to what's available now.
No, the problem isn't that older plants which have seen significant wear and tear face too many regulatory hurdles to continue operating - it's that NEW plants, using more advanced, safer technology, are facing too many legal hurdles in most cases to get built. We're talking about Passively Safe fourth-gen reactors, the sort that would be able to survive even something like Fukushima without a meltdown. We can't get these old plants replaced with new ones, so the old ones keep running with increasingly creaky equipment? That strikes me as downright crazy.
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.
I don't always use unix-like operating systems; but when I do, I prefer FreeBSD.