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Comment by rus20376 | Hacker News Reader

rus20376

Better capturing of storm runoff seems like a good idea to me, but if nothing else it would still be dependent on weather events.

I understand there is a lot of political pressure against desalinization plants in California but I never understood why? These are used effectively in other countries including the border country Mexico. The source is the essentially infinite and steady supply of ocean water, which would seem to be a clear win, right?

The arguments against desalinization in California have only been hyperbolic and devoid of facts. i.e. "environmental disaster!", "unsustainable stop gap!"

What are the environmental concerns at play that seem to be hyper specific to the California coast and no other coastal country employing these processes?

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Desalination is not an hyperbole, it is an environmental disaster. What do you think happens when hundreds of millions of gallons of water is separated from the salt? Where does the salt go? Back in the sea is where it goes. And what happens to the sea life when you suddenly increase the salinity of the water by a lot?

Edit: Too many people are responding to this comment with the argument ocean is big, a little bit of salt water doesn’t change anything. That is not what the ecological damage is about. Think of this as a dropping ice cubes in a bathtub scenario. The overall the bathtub water isn’t going to cool down a lot, but the water around the ice will be very cold. And that is the problem. Oceans are sensitive and hyper local problems can have devastating effects across the globe. If there was a technology to uniformly distribute the brine across the ocean, then we would be fine, but until then, “the ocean is big” is not a great argument.

> What do you think happens when hundreds of millions of gallons of water is separated from the salt?

Where do you think the water that forms the runoff comes from? Rain. Rain from where? Clouds. Clouds from where? The ocean is a significant source of rainwater.

Where do you think the water goes when the river takes it to the ocean? Well, goes back into the ocean.

How many gallons of water does the ocean have? Trillions? A few million will not measurably increase the salt content of the ocean. And, because it's a cycle, it already happens naturally.

So keep the cycle going. Guide the cycle to be more useful to us.

I just looked it up, according to usgc.gov, Californians use on average about 181 gallons of water per day. There are about 22 million Californians. That's several billion gallons per day. Just pointing that out.

>And what happens to the sea life when you suddenly increase the salinity of the water by a lot?

Nothing if you appropriately dilute it or a some very localized damage

Even if all the water california used came from the ocean, that is 0.00000004 of the total ocean volume per year. Will this really increase salinity?

I suppose if you were able to dissolve these tons of excess salt equally across the total ocean volume this wouldn't be an issue. But it has to be dumped back in somewhere, and the local salinity increase in that area even if only temporary should still be considered.

Put the salt in tanker ships and dump it out at sea across a wide area. Cargo ships are massive, and desal plants would likely be in bays (i.e., not on "wild coasts") where there are ample loading docks in nearby harbors.

Again, seems like a solvable problem with minimal incremental infrastructure (particularly given the overall cost of desalination plants with adequate urban capacity).

Please look up how desalination works, you’re not dumping salt in the ocean. It is millions of gallons of brine. For every gallon of water produce, the waste is more than a gallon of brine. It would not be commercially viable as compared to say building a reservoir or not growing almonds and alpha alpha in the middle of the desert.

And they are considered. These are actual considerations that any industrial plant has.

The local increase of salinity can made arbitrarily close to the local salinity by pre mixing it with an appropriate amount of water

That’s not how it works. Think of this as what happens when you drop a couple of cubes of ice in a tub? The temperature of the tub doesn’t go down for sure like you said, but the water around the ice cubes will be very cold. That’s what happens when you release highly concentrated water in the sea, the marine life is decimated but overall the salinity of oceans doesn’t change.

Now you could argue you could dilute the release water, but then why desalinate?

"Now you could argue you could dilute the release water, but then why desalinate?"

....because you dilute brine with seawater so its a simple and (overall) energetically cheap solution.

Why would the salt be dumped back in the ocean? Wouldn’t it be sold to consumers?

The "salt" is in the form of brine, it's a liquid and you'd need huge evaporation ponds to keep up with the outflow if you wanted to dry it all out to sell. If you put your desalination plant near urban areas, where the demand for fresh water is, then the land you'd need for evaporation ponds would be a lot more expensive, and I suspect the profit margins for salt are fairly tight (sea salt competes with salt mines where they just scoop the stuff right out of the ground.)

> dilute the release water

You can mix the brine into treated sewage.

I am likewise baffled by this. I completely understand the concern about the salinity of the return liquid but that seems an obviously solvable problem. And it is a problem that so obviously needs to be solved that it’s the first objection that is always raised when discussing desalination, so it hardly goes overlooked.

Capturing “every drop” of run off is likewise environmentally damaging to all kinds of watershed ecosystems if done in a blunt thoughtless manner.

I just don’t get it.

If the solution is obvious it eludes me.

desalination probably isn't cost effective enough to grow almonds

Yep, agriculture still 80% of water usage, because it's free.

Same up river from California on the Colorado (Utah, New Mexico, Arizona) as well so it's not like changing industrial or residential consumption by even 50% makes a dent. Limiting or taxing export of water intensive agriculture (alfalfa, rice) would though!

But what will the Saudi princes do without their steady supply of US-subsidized alfalfa?

It’s easy to pick on the handful of obviously profligate uses of water but California’s wildly productive farmland does produce a lot of important crops and just saying “no agriculture here anymore” isn’t much of a solution unless we don’t intend to keep eating.

Or just cutting the government subsidies on beef and cotton production on lands that use discounted reclamation water.

I think you state the point perfectly. Desalination presumes that the "need" is for drinking water. 80% of the water that humans use in California is for agriculture, only 20% is urban use.

Drink it or eat it, it still goes down the pie hole!

Desalination is energy intensive and expensive. It would make sense in urban contexts and not for agriculture. This sets up a political fight since the majority of the state’s water usage derives from people who already rely on government handouts for water. Obviously people do not want to pay higher utility rates to further benefit people they are already subsidizing.

OK? Without water you'll die, so invest that energy and capital. Other places seem to manage it and the more desalination facilities that are built, the more likely it is that technological and process improvements can bring down the cost. An extremely obvious approach to the energy requirement would be to exploit tidal power, which conveniently comes from the same source as your product input.

There is plenty of water in California. No-one is going to die of thirst so it doesn't make sense to frame the issue in such dire terms.

The cost of desalinated water in California exceeds the market rate, so nobody in the state wants to pay for more expensive water. What they do want is for someone else to pay the bill for them. This is a purely self serving goal and it sets off political fights with the people who don't want to pay for someone else's water.

In places where the market rate for water is higher (Israel), or where the cost of energy is lower (Saudi Arabia), then the situation would be different but in California it is just about trying to get more benefits stuff from the government.

It's a synecdoche, to indicate that the state as a whole is consuming more water than there is available, drawing down its water table and so on. I didn't intend it to be interpreted literally. Water shortages are already threatening communities in Arizona: https://www.hcn.org/articles/south-water-what-happens-when-a...

The market price for water in CA is artificially low, in my view. Many corporate users are effectively subsidized with fixed or below-cost supply. Nestle, for example, was taking 58m gallons/year (about 25x its land allocation) from streams in the San Bernadino forest to bottle as Arrowhead water until the state intervened in 2021: https://www.ecowatch.com/california-nestle-water-public-land...

Your dismissive comment that 'it is just about trying to get more benefits stuff from the government' should equally be applied to incumbent market actors if you wish to be consistent. I did not argue for subsidy, but for desalination as a hedge against water shortages, and that the costs of desalination could likely be significantly reduced.

They're not specific to California. Desalinization is highly energy-intensive and you end up with a bunch of brine you need to do something one. One popular solution to these concerns is ignoring them.

Serious question… there are lots of salt plants in SLC turning the briny water of the lake into table salt and other useful minerals. Why can’t the same be done with desalination plants?

I’m not an expert but I have to imagine the contaminants used in pretreatment they discuss here are an issue. https://www.wired.com/story/desalination-is-booming-but-what...

Salt evaporators need huge areas of cheap flat land, like those in the San Francisco bay near Newark.

With no knowledge of this stuff but just a child's level of thought, you must admit that it is at least amusing that we both have salt fields and that we don't want brine.

They're is nothing special about desalination plants.

California is passionately against building anything!

At this point it feels like California is a failed state.

Yes it’s terrible definitely don’t come here.

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