This wired article seems to indicate that it only costs twice as much to desalinate ocean water as it costs to import colorado river water. Twice a low number - a water bill of $50-$100 or something - is still not very much money, especially compared to the other expenses of living in California.
It sounds like the problem is solved. If you can also cut consumption by 50% - use low flow toilets, no irrigation landscaping, water recycling showers (the shower water goes through a membrane just like the one here to remove the dirt and soap), and make sure to use the dishwasher instead of the sink and an efficient front loading washer - you’d pay the same amount per month they pay right now.
I remember being made to sit through various environmental awareness classes in middle school science class. Instead of learning useful stuff, they had videos on some worldwide shortage of freshwater, implying that the Western world is all going to die of thirst or at least not be able to shower.
Now, less advanced civilizations can’t build plants with reverse osmosis membranes. Even if they have the money, corruption funnels that money away from where it is needed into the pockets of a few rich thieves. But that’s their problem, not the Western world’s problem - you can’t be blamed if a civilization can’t even fend for itself.
If reverse osmosis is this cheap, and conservation measures that don’t really involve any real sacrifice (with water recycling, your showers are just as long. Dishwasher gets the dishes cleaner than the sink because it uses heat to sterilize them. Front loading washers get the clothes clean with less wear on the fabric and less water used. You don’t have to mow a no irrigation landscape. Modern low water toilets work just as well or better), we can move on to more important things.
Desalination is, to me, a part of the solution. But it also comes with its own set of problems. It’s high energy. Sea water intake damages sea life. And brine solution discharge back to the ocean is also problematic.
But I still see it as part of the solution along with conservation and recycling (toilet to tap).
Buried water intake may prevent damage to the local fauna though that’s still being argued.
As for what I think should be done with the brine discharge, I just wrote about it last week. Scroll down to the bottom diagram for my theoretical proposal for arid coastal communities.
I don’t see a problem with dumping the brine into the ocean, so long as you use a long enough pipe. You can’t take enough water from the ocean to matter. For that matter, all the water, after it is used, will eventually flow down drains into the ocean, so it’s a temporary borrowing of water from the ocean. Only loss is energy and if it’s only twice as expensive, the energy isn’t that much.
Unless there isn’t enough, and at that point, it doesn’t matter how cheap it is. Remember those brownouts California had a few years ago? There may not be enough electricity available to desalinate all the water needed.
Although desalination can be used to supplement freshwater supplies for personal consumption, it is not a solution for the wide scale depletion of freshwater used for agricultural and industrial purposes which dwarfs personal use but contributes to fouling of downstream freshwater resources. Not only is desalination (even RO desal) an energy intensive process and requries regular backflushing to clear accumulated salts and sediment from the filters (comprising a source of environmental pollution), but also water then has to be delivered to the final application by some maintainable system. This means moving water both inland and uphill at more cost of energy and infrastructure, the cost of which rapidly becomes staggering when having to deliver to geographically distributed users. The three decade long Libyan Great Man-Made River project, which loses more water than it manages to deliver to Ajdabiya, Bengazi, Sirte, and Tripoli, should serve as a lesson to anyone who underestimates the difficulty in moving large volumes of water across long distances, notwithstanding the challenges of pratical large scale desalination.
The solution to depletion of natural freshwater resources isn’t to implement yet another complex technical system at large cost and energy demand, but to limit the growth of water-intensive crops in locations that do not have sustainable natural water supplies and implement irrigation methods that are much more efficient in conserving and deliverying water to the user. Even at that extent, there are many nations such as India, Pakistan, Brazil, Peru, and the Eastern Ukraine, who just have water demands that are substainally beyond sustainable resources and for which desalination of sea water, even at the maximum practical extent, could only provide a modest portion of the anticipated demands. One of the global strategic resource concerns of the 21st century is freshwater availability and allocations, and many military and intelligence strategics are focused on the scenario of open conflict over availability of scarce freshwater resources.
I’ve said it before. We’re going to see water wars. Literal wars involving death & destruction, because there are so many places aound the globe whose water needs far outstrip any sustainable local sources.
As near as I can tell, living close to the desalination plant in Carlsbad, the biggest barrier to getting the water is the non-stop lawsuits from environmental groups. Dealing with the lawyers seems to just be a cost of doing business these days. To me, seawater coming in at 33.5ppt and leaving as a saltier 40ppt seems like a minimally harmful solution if you otherwise discount the small population of sea animals that will die due to being sucked into the intakes or killed by the extra minimal salinity.
Assuming the reservoir that it is pumped to otherwise has minimal evaporation and services the local area around the plant, I think it is absolutely a viable solution. While the same environmental groups also killed off the San Onofre nuclear power plant just a few miles up the road from there, I’d like to think the ever growing presence of solar installation everywhere I look will provide lower cost energy to do all that water pumping that is required.
It’s more a matter of enabling it than allowing it. At least in San Diego, reclaimed gray water is already used for irrigation and other uses. However, it has to be delivered with separate infrastructure, which to us means a network of purplish pipes, and there aren’t enough of these. The last I heard, San Diego has to reclaim a certain amount of water for legal reasons, and that amount is significantly more than can be pushed out over the purple pipes. The surplus is pumped into the ocean. How frustrating is that?
Meanwhile, I have doubts that desalination is really only twice the cost of diverted river water. Do we trust Wired on that point?
Which is fine, but those policies are never going to happen on the necessary scale. If “governments all learn to sing kumbaya and do everything right” is the only answer, we’re doomed. So while we’re waiting for the unicorns, we may as well work on some technological solutions that don’t depend on human nature changing orthogonally to the course it’s been on for the last few hundred thousand years.
In the US, we have the most powerful political party in government dead set against even acknowledging a problem exists, with a literal aversion to science and facts. And we’ve got one of the sanest governments on the planet.
When the price of water doubles the thought will cross people’s minds. Modern low flow toilets work better than older “full flow” models. It’s a cheap modification to homes. Older washing machines are being fazed out in a couple of years if not next year. Sprinkler systems will be replaced with drought resistant grass and direct irrigation.
The only thing I don’t see happening is home recycling systems.
People need water and will try to pay for it the most economical way possible.
The “technological solutions” to overuse of unsustainable freshwater resources for agriculture and industry are no more viable, and certainly less cost effective, than implementing more sustainable solutions for high efficiency irrigation and reuse of non-potable industrial wastewater. Again, I direct you to the Great Man-Made River Project, a supposed “technological solution” to trying to maintain agriculture and industry in regions with limited freshwater availability which has been a complete failure at a cost of tens of billions of dollars, and is only a fraction of the scale that would be required to satisfy the freshwater needs of California, much less India, Pakistan, or Brazil. (The irony there is that most of the places in Libya which are being ported water from the Nubian Sandstone Aquifer System are near coastal regions which could support extensive use of desalination for personal and limited agricultural use). The costs of trying to implement an infrastructure to deliver desalinated water throughout California, or even to specific targeted inland regions to offset current usage of water from the Colorado River, is just beyond conception; hundreds of billions or trillions of dollars above and beyond the construction and operating costs of the desalination facilities themselves.
I question that the United States (or State of California) governments are “one of the sanest governments on the planet”. In fact, on ecological issues both governments have shown both moral and practical ineptitude in implementing even very modest policies for effective waste mitigation, energy independence, and fair resource allocation and usage. It certainly doesn’t help that the executive agenda and often regulatory focus changes on intervals of less than a decade, meaning that any large scale, long duration effort is almost impractically difficult to sustain even when there is substantial impetus to do so. Invoking some kind of logistical magic to transport water from hypothetical vast desalination plants on the coast or in San Francisco and Suisun Bay to the agricultural regions across the Central Valley is like suggesting that we can just use a really long ladder to reach the moon.
Greywater reclamation and recycling is a good step toward efficient use of scarce resources, but it is best implemented locally at the site of use, rather than trying to create a large general infrastructure for redistribution. Effective implementation of greywater reclamation is really more a matter of updating building and facility codes and encouraging industry to take the very modest steps to implement greywater systems (e.g. tax incentives to offset installation and maintenance costs) which will ultimately be revenue neutral or even positive as the artificially subsidized water prices rise with scarcity. But greywater use by itself isn’t sufficient in the case of completely unsustainable water usage as in the California ag industry. The real answer there is to shift away from water intensive crops and in the case of the Eastern side of the state, stop trying to grow food in a desert.
I think you’re being a little pendantic, Stranger. There damn well are technological solutions, they are just too expensive - and the cost paid now may not actually be the cost you see at scale, so the price may be misleadingly expensive.
For example, you could use farms in a box instead of needing vast sections of arable land in the first place. Very little water is used as they are sealed grow rooms, we could develop robots to tend them (again, expensive now but you could build vast numbers of robots, once you have a reliable and simple design, much cheaper)
Shower heads and toilets have been mandated in CA for over 30 years.
But keep those profound, cutting-edge ideas coming!
Especially the extract-salt-from-brine-and-dump-on-ground.
At last! A literal “Salt the Earth” proposal!
We who are dirty and smelly with brown lawns thank you all!