The flush tank of my toilet was leaking. I called a plumber, and the first thing he did was to scoop up more than 2 handful of salt solids from the flush tank and clean it well - I wasn't aware that our community uses untreated hard water for toilets. And I was shocked, as I wasn't aware this happened, at the amount of left over salt that had accumulated!
Salt is a by-product of desalination and, as I understand, not easy to dispose without affecting the ecology of the area where it is disposed (let's not forget that salting of fields was done as an act of warfare against the enemy to make their lands barren, and then there's the natural Dead Sea - https://en.wikipedia.org/wiki/Dead_Sea - that exists and highlights what happens to marine life when water has too much salt content in it). Unless salt waste disposal is solved, desalination isn't going to become popular.
Salt is a by-product of desalination and, as I understand, not easy to dispose without affecting the ecology of the area where it is disposed (let's not forget that salting of fields was done as an act of warfare against the enemy to make their lands barren, and then there's the natural Dead Sea - https://en.wikipedia.org/wiki/Dead_Sea - that exists and highlights what happens to marine life when water has too much salt content in it). Unless salt waste disposal is solved, desalination isn't going to become popular.