I worked for a desalination company in the 1980s. From then until a few years ago, I would have disagreed with your assertion. Some recent advances have me rethinking that, however.

https://singularityhub.com/2019/06/18/inching-towards-abunda...

Have you seen this desal operation in Australia?

https://en.wikipedia.org/wiki/Sundrop_Farms#/media/File:1604...

It's a farm in the middle of the desert that gets all its water from desalinated sea water powered entirely by an array of mirrors.

I'm fairly skeptical of massively expanding existing RO operations due to how we tend to handle brine - which (from what I've seen) is usually just dumping it in the general area we pump from.

However my past concerns for altering seawater on a planetwide scale are much abated. Rising sea levels and glacier melt have put an end to that.

Better membranes and renewable-powered desalination plants are not going to do anything about the waste problem. Has there been any progress on that?

Brine disposal has always been my concern. I haven't come across anything promising but I'm well out of the loop.

wouldn't releasing brine into the ocean be viable with a suitable dispersal mechanism? Or are there additional chemicals released from the plant?

Yes. We already do this for all sorts of things, including sewage. (https://en.wikipedia.org/wiki/Marine_outfall)

Can't we just have giant "salt plains" where we allow the brine to evaporate and we just collect the remaining salt/minerals?

Maybe I'm crazy or not informed enough, but I always thought this water-desalination thing was a solved problem. Then I got confused when they talked about how there is "brine waste" and it's a huge ecological problem. Why do they stop short of full evaporation of the brine?

We don't need desal, there is plenty of water if we dont waste water on golf courses and lawns in the desert.

I tend to agree with you. If water is precious then why is it so cheap? The avg family uses thousands of gallons a month. It's difficult to get people at current prices to stop wasting water. California farmers pay an average of $70 per acre-foot for water to irrigate crops (326,000 gallons) I live in an apt in California that doesn't even meter it. I can use all I want and the price is included in the rent. We have to get out of this mindset that water is a free gift from the sky and start pricing it in such a way that solutions to shortages become cost effective to implement.

Where does your wastewater go in your city? As long as you are not bottling it up and selling it out of state, isn’t most of it returned to the California ecosystem?

If I recall, this is the same point the Nestle CEO infamously made. It's a good point, but clearly the world is not ready to have that conversation.

It's a plague everywhere. I'm on the Gulf Coast and our waterways are massively polluted - entirely by lawn runoff.

Not sure if we have plenty of water for all those almond trees.

Deal with beef and dairy first, they use far more water for far less output: https://www.truthordrought.com/almond-milk-myths

Does Desalination remove DDT and its breakdown products?

https://www.latimes.com/environment/story/2021-04-26/ddt-was...

Yea