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California Is Drilling for Water That Fell to Earth 20,000 Years Ago

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Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#11

Post by colechristensen »

ChuckMcM wrote: post #7
xasos wrote: post #6

Earlier quoted context omitted.

MIT Technology Review wrote a great article on this: http://www.technologyreview.com/featuredstory/533446/desalin...

That is a good summary. A friend of mine is looking at putting a passive desalinator on the ocean floor off the coast of Monterey. Basically its a pipe with the permeable membrane surrounding the submerged collector. The pipe carries fresh water to the surface and as you pump out fresh water, the pressure of the ocean at depths of up to 1000 meters pushes in more water through the membranes, desalinating it in the pr…

You can do it, but it turns out the work to pump water up to 1400 psi in a pressure vessel before it goes through a reverse osmosis membrane is about the same as the work to pump desalinated water up from the bottom of the ocean at 1000 meters. There are different inefficiencies in each situation, but I'd assume maintaining equipment 1km below the sea would trump them all.

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#12

Post by cma »

colechristensen wrote: post #11
ChuckMcM wrote: post #7

Earlier quoted context omitted.

That is a good summary. A friend of mine is looking at putting a passive desalinator on the ocean floor off the coast of Monterey. Basically its a pipe with the permeable membrane surrounding the submerged collector. The pipe carries fresh water to the surface and as you pump out fresh water, the pressure of the ocean at depths of up to 1000 meters pushes in more water through the membranes, desalinating it in the pr…

You can do it, but it turns out the work to pump water up to 1400 psi in a pressure vessel before it goes through a reverse osmosis membrane is about the same as the work to pump desalinated water up from the bottom of the ocean at 1000 meters. There are different inefficiencies in each situation, but I'd assume maintaining equipment 1km below the sea would trump them all.

I think he really means you bail the water from the top rather then pump it, leaving an airgap at the top that the pressure from below gradually fills with more water through the membrane. But then again unless you bail all the water, that leaves only a small pressure differential, and if you bail it all, it gets less efficient as it fills back up and the pressure differential gradually reduces and lifting it from the bottom takes a lot of energy :P. Yeah, I don't understand what he's getting at with the design.

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#13

Post by pyrocat »

leppr wrote: post #5
stephengillie wrote: post #2

And this means that soon, many of us will be eating food grown with 20,000 year old water.

if water in bottles expires in a few years i can't even imagine how bad this unpackaged water will have turned. this is totaly outragous

pretty sure water in water bottles only 'expire' because of the plastic leaching into the water over time. "Unpackaged" water has been sitting in the earth for thousands of years, as evidenced by this article, and is perfectly safe to drink.

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#14

Post by jonnathanson »

leppr wrote: post #5
stephengillie wrote: post #2

And this means that soon, many of us will be eating food grown with 20,000 year old water.

if water in bottles expires in a few years i can't even imagine how bad this unpackaged water will have turned. this is totaly outragous

In fairness, I think it's not so much the water as the bottles that go bad. That type of plastic is not easily biodegradable, but it is photosensitive, and it weakens over long-term exposure to light. As the bottles break down, they leach toxic chemicals into the water and also lose structural integrity.

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#15

Post by blhack »

pyrocat wrote: post #9

All of this reminds me of a trip I took about 10 years ago to Palm Desert. Even then I was stunned by opulence of their water use and the utter disregard for sustainability. It's a city built in the desert that regularly reaches 100+ degrees, and yet every house had a bright green grass with sprinklers running constantly. One of the main attractions was their huge amounts of golf courses, that were of course always k…

Sounds like a lot of Phoenix.

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#16

Post by eyeareque »

pyrocat wrote: post #9

All of this reminds me of a trip I took about 10 years ago to Palm Desert. Even then I was stunned by opulence of their water use and the utter disregard for sustainability. It's a city built in the desert that regularly reaches 100+ degrees, and yet every house had a bright green grass with sprinklers running constantly. One of the main attractions was their huge amounts of golf courses, that were of course always k…

you'd hope that the water they used was at least from waste water treatment plants.. however that water was fresh at one time, and used by a big city in the middle of the desert.

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#17

Post by fletchowns »

nawitus wrote: post #4

One solution to producing water is desalination. You can effectively get unlimited amount of water, but you pay for it in energy. A quick Google search finds that there's a desalination plant under construction in Carlsbad, California.

There's also the problem of what to do with the high salinity waste water that is generated from the process. Simply dumping it back into the ocean can cause environmental problems.

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#18

Post by tempestn »

One major problem that needs to be tackled is that much of California (and the world) is still using flood irrigation[1], which wastes massive amounts of water to runoff and evaporation. Fortunately this is starting to be tackled due to higher water costs and government subsidies. (But of course it's only part of the problem, and these subsidies carry some moral hazard[2]. Also, it's interesting to note that not all of the water "wasted" in less efficient methods of irrigation is actually wasted.[3])

[1] http://www.mullerranch.com/making_news/sacbee_drip_2_2014.ht...

[2] http://www.circleofblue.org/waternews/2014/world/conserve-wa...

[3] http://www.worldwatch.org/node/5942

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#19

Post by sergers »

leppr wrote: post #5
stephengillie wrote: post #2

And this means that soon, many of us will be eating food grown with 20,000 year old water.

if water in bottles expires in a few years i can't even imagine how bad this unpackaged water will have turned. this is totaly outragous

That all started due to NJ state law requiring everything to have an expiry date.

http://www.smithsonianmag.com/smart-news/water-never-goes-ba...

Re: California Is Drilling for Water That Fell to Earth 20,000 Years Ago

#20

Post by jefurii »

tempestn wrote: post #18

One major problem that needs to be tackled is that much of California (and the world) is still using flood irrigation[1], which wastes massive amounts of water to runoff and evaporation. Fortunately this is starting to be tackled due to higher water costs and government subsidies. (But of course it's only part of the problem, and these subsidies carry some moral hazard[2]. Also, it's interesting to note that not all…

I was in the Central Valley the other week and asked my dad about these little tanks that had popped up on farms in the area. He told me they were part of new drip irrigation systems. So things are changing slowly.
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