California water dreaming
Last week I was asked by my Rotary Club to give opening comments before a guest speaker from Lockheed Martin talked about new technology developments, so I decided to talk about water and technology.
To set the stage, we're having an unusually average water year in California. The story about Bill Gates walking into a bar and making the average patron a millionaire applies - California has lots of below-average years and a few really wet ones.
This year's precipitation is kind of average - most of the state had slightly above average rainfall, some slightly below. The snowpack's water content is at or slightly below average. The reservoirs shown above are mostly below average due to the multi-year drought. Groundwater conditions are much harder to find, but we already know the answer - they range from not-good to extremely bad. What little more rain we'll get, however welcome, will not change any of this. We're still in a drought.
Please stop saying that the California #drought is over because it just rained or snowed (a bit) in March. #water pic.twitter.com/UKcf8Ms5vA— Peter Gleick (@PeterGleick) March 17, 2016
So in my comments I mentioned three technologies that could help water supply: low-tech, current tech, and future tech.
The low-tech model being tested now is flooding farmland, even when plants don't need it, to maximize percolation for groundwater storage. This is different from flood irrigation, a common and wasteful way to water orchards and other crops that may have similar groundwater benefits but is taking water at the wrong time, when it's most needed in-stream. Flooding for percolation purposes is being tried in midwinter, and may replace an expensive large reservoir that we'd otherwise be pressured to build. It's an experiment to see how well it percolates and how well the orchards and other areas tolerate it, but seems like a good idea.
The current technological system to change water supply is recycled water for potable use, something I've talked about quite often. My former water district already purifies wastewater to this standard but only uses it for landscaping and industrial uses. In a few years we plan to start drinking it, which has been done for years in other places like Southern California and Singapore, and in space. The main technology involved is reverse osmosis - hardly new, but new techniques make it more efficient.
The same technology is used for ocean desalination, but it sucks up a lot more energy and has other environmental consequences. The biggest environmental difference between potable reuse and ocean desal - aside from energy - is that reuse works best at large wastewater plants in urban areas, limiting sprawl, but ocean desal can open up development in any location near the ocean.
Finally, the future technology I'd like to see applied is a smart grid for underground, residential rainwater retention tanks with two-way pumps connected to storm sewers. When a storm approaches, the grid activates and pumps out the tanks in advance. When the storm hits, the tanks not only take in runoff from roofs but also pump water in from storm sewers, temporarily, shaving the critical peak off a flood. These tanks aren't just for rainwater, they're a form of flood protection, and their combined value makes them worth the price.
The first smart cisterns are happening in Los Angeles, so making a grid use out of them is the next step.
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28 comments:
Eli you are a member of Rotary?
Not that there's anything wrong with that but we have all constructed an image of you based on a whole lot of assumptions (some of them supported).
For god's sake if you are going to out yourself as a Rotary Club member you can't do it by starting your post with Last week I was asked by my Rotary Club
Had you begun with:
Call me Ishmael. Some years ago - never mind how long precisely - having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world then nobody would have blinked an eye.
Does water recycle equipment take out antibiotics, hormones, and dope residue from the water?
PG, I think that you meant to address Brian. :-)
On the matter of Californian water, I'd have thought that a thumping El Niño would be the time that the state would be particlarly wet. If an El Niño of this size can't top up the reservoirs to any sigificant extent, then there might be ongoing problems...
Bernard have you ever seen Eli and Brian in the same room at the same time? Thought not. Typical Warmulicios something or other.
PG.
You're right...
Rotary good, Brian's lack of interest in curbing loss of water by evaporation , less so.
Hi folks, yes I'm a member of Rotary - good social event and good speakers, although you have to put up with some of the members who give opening comments.
FWIW, the social spending on lunches etc. is not 501 c/3 tax deductible, while all the other fundraising is done through volunteers (except some paid staff at the regional levels I guess). Very little of the charitable funding is spent administratively.
On El Nino, I was going to write that it's unusual but not unique for a strong El Nino to result only in average precipitation in California. If that becomes the norm, then California has yet another water problem.
Russell, are you referring to evaporation from flooding fields? I don't expect that would be a big issue in midwinter for the week or so that the water would be on the surface.
Fernando - sorry I forgot. Yes, reverse osmosis is very efficient at taking out other large-molecule contaminants. Those contaminants are much more likely be present in "natural" water sources that are downstream from other municipalities.
Brian, I mean evaporation when the sun shines and the rain doesn't fall.
I like the Rotary's plain vanilla approach to disasters a lot- what's not to like about folks who respond to catastophes by filling airplanes with doctors, flashlights warm clothes and tarpaulins and sending them where needed the next day
I've seen them do a lot of good in the aftermath of major earthquakes in Guatemala and Pakistan!
http://adamant.typepad.com/seitz/2008/01/a-world-turned.html
The <a tag bug is back- sorry for the non-link
Brian I an certain that Rotary is a very fine community service organisation. My son was the beneficiary of a Lions Club scholarship to Japan in year 10 of high school. Now 19 he is fluent in Japanese (Including Kunji ) having continued it at Sydney University.
Mom Rabett used to wonder why Eli was not a big wheel. Ms. Rabett pointed out that the Bunny has the habit of going about in circles.
We could hire a bunch of Syrian refugees to come to California and teach us all to live on less than 8 l. of water per day. Such water conservation has its own technology. : )
All the houses in our development have architectural drains that divert all surface runoff to the storm drains. Fifty years ago, there was a stream that ran into a marsh/wetland (likely originally a beaver pond). At one time, our town had more wind mills per capita than any other town in the US. Now, the architectural drains prevent the aquifer from recharging, and loss of the wetlands means water does not evaporate to recondense on the Sierra.
A good chunk of California's long term drought is an unintended consequence of development with artificial drainage moving water quickly out of the system. These days, even ag crop fields have drains.
Our water rights system and hence water pricing is an accident of history. These days most of California's GDP is produced by a tiny fraction of the water used (Silicon Valley). While ag is important, their water costs do not reflect the current value of the water. If Ca ag had to pay full value for its water, they would find that they could make more money growing crops using much less water.
If the big ag companies had half a brain, they would be bringing Syrian farmers over to show them how to farm using less water.
The magnitude of stored fresh water loss by evaporation is staggering - more than a ton per day per capita globally.
Many nations lose more than end users consume.
In our big desert reservoirs like Lake Mead, Lake Powell, the figure for evaporation is several percent, as I recall. Not tiny, although not a game changer either if it were somehow fixed. I imagine some places are worse (Aswan?).
Aaron brings up an interesting point whether our rush to flush rainwater west into the ocean changes California precipitation. I don't know, I've never heard that argument before. Could say something similar about draining groundwater which would otherwise support surface water systems and their evaporation. OTOH, we've also created giant artificial reservoirs throughout California that add lots of evaporation. I don't know how that balances out - I suspect it's not an important aspect of precipitation, though, compared to weather patterns over the Pacific.
Turkey is one of the nations where less than half the water makes it to the consumers.
Mead evaporates 3-4 meters a year, as do the elements of the system feeding it - and the canals downstream ,
A few % a year times N is millions of acre feet in California alone .
It's hard to find a handle on the % of the water in the Colorado that evaporates from the river's entire length.- Please let me know if you know
Why is it that no matter the subject, environmental dilettantes hew to cute and heart-warming boutique projects that cannot scale or propose hair-shirt guilt trips? FYI, being the people responsible for our community water system conservation program, the wife and I have held our water use over the last four years to 30-gallons per day without any help from Isis. What is your household water use Aaron, Brian? I'm sure you guys check your meters regularly to ensure you have no leaks, right?
Evaporation is a concern. I'm not convinced Russell's micro-bubble technology can work and/or scale while preserving the recreational use of surface impoundments.
A proven, progressive way to reduce evaporation is to put the water in the ground. The enlightened water engineers of Southern California have been doing this since the middle of the last Century.
Kern County
Orange County
LA County
LA County Sea Water Barrier
I congratulate Howard on saving by conservation 3% of what he loses by evaporation.
It will take outdoor pool and instrumented pond tests to address his- and my own concerns about systems biology, , but may I remind him that the water in his favorite swimming hole already contains ~ 20 mg/l of dissolved air and on the order of ten thousand ambient natural microbubbles.
Doubling the albedo of surface impoundments entails dispersing on the order of one part per million by volume of microbubbles of micron dimensions.
I meant to congratulate Howard on consuming 150 liters a day less than I do- but that's still just 15 % of his per capita share of evaporative stored fresh water loss. May I ask what he thinks of LA 's black ball solution to its reservoir woes?
Russell: I get my water from a groundwater system which is fed into tanks and conveyed through pipes, so I don't know how much evaporation could be prevented by employing a DAF to reduce albedo. Most surface waters I measure have about 10-mg/L O2.
Thanks for the kudo's, however, I don't conserve, the wife makes me do it for political reasons since we are the neighborhood conservation KGB, Caesar's spouse rules apply.
Residential use is pretty poultry in the grand scheme. Not only evaporation, but evapotranspiration and the exportation of water from western US deserts by exporting food to the east coast and beyond is the real bite in the water budget.
As for the black balls, I never paid it any attention beyond thinking it was another publicity stunt. $35Million to ball a 3.3BG reservoir with a 10-year lifespan. They claim a 300MG savings. I assume that's per year, 10-year life 3BG at a cost of $35M=$11.7/1000G. A desal plant is 10-times cheaper to build and operate.
Your ton per day per capita assuming 350M people in the US is 84,000-MGD, or about a quarter of the 355,000MGD total withdrawl (2010). The 1963 Monsanto metalized plastic confetti patent claimed $400M annual loss in the US. Assuming 10-times inflation at a present value of 10-cents per 1000G yields a loss of about 110,000MGD, which is in the same ballpark as your rule of thumb.
Can your system save water for less than 1-cent per 1,000gallons? What sort of market penetration is reasonable, 20%? 10,000MGD for recharge into the Ogallala and Central Valley aquifers which currently use about 17,000MGD and 12,000MGD, respectively.
In theory, it sounds like a winner.
How do you sell it? That's the rub.
"then there might be ongoing problems..."
IDZ, Instant Desertification Zone.
Cali families should move out.
Howard:
You have indeed identified the problem -- the hydrosol project aims to find a way around one of the central paradoxes of conservation economics :
That water is too cheap to conserve.
LA's black balled reservoir vividly illustrates the point- the median price of agriculture water is on the order of fifty bucks an acre foot, and no usefully durable ( oil slicks are not ) physical material comes as cheap as fifty dollars an acre.
Thankfully , one thing is cheaper than water, and freely available in even the poorest places on Earth- air, which is what hydrosols are made of .
A paper on evaporation economics building on the one published in Climatic Change has been submitted for peer review .
With all due respect, Russell, the same can be said for hydrogen. The problem is transforming the raw material into a useful product. Have you tested your system on the scale of, let's say Walden Pond?
I was thinking about your ideas while removing the covers from our local swimmin hole this morning. Does your hydrosol also block temperature induced evaporation at night?
Have you considered any application of this process on waste water ponds? I ask because typically in summer, these can fail due to higher temperatures upsetting the bugs.
Howard,
Here's what the American Water Research Association blog has to say- it includes a free link to the paper:
http://aquadoc.typepad.com/WaterWired/2011/07/hydrosols-and-microbubbles.html
So it's the efficiency of the DAF pump that is holding this back.
Howard, I was a director of Santa Clara Valley Water District, let's just say I'm aware of groundwater storage.
And I live in a condo with no yard, our water usage shouldn't be too high. There is the HOA's usage, but I still think that doesn't add up to much.
DAF pumps are not designed for this sort of thing- the bubbles they make have ten thousand times or more the optimal ( 1 micron cubed ) volume for efficient Mie backscattering of solar heat.
Using the pressure already available in gravity fed water systems to pressurize air in turn can easlily double the amount of dissolved air in the water, and releasing the air-supersaturated water through the pressure drop in a vortex nozzle generates microbubble hydrosols of high albedo. Most of th energy cost resides in distributing rather than generating them .
Best read the paper.
Have you looked at the current firefighting foams? They're a problem (persistent and toxic surfactants) but the push to clean those up is ongoing.
The idea is to spray threatened buildings with a foam that will last several hours, then flee the area before the flames arrive.
Might be some overlap in technique and application could develop.
https://www.google.com/search?q=fire+fighting+foam+persistent
Hank, three decades ago, David Evans pardon the expression floated a proposal in the form of a Daedalus column in Nature ,to fight the greenhouse effect by floating shaving cream or firefighting foam on the oceans.
Last year a another British journal published a paper on turning sea water into floating salt foams , which persist indefinitely when dried out on a lab shelf, but dissapear as soon as rain or spray hits them
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