Salinity rises in the soils and aquifers. Worse case may be the Aral Sea, but the Aswan High Dam has had a largely negative impact.
I found the article below that explains what I think SunkinCiv is talking about?:
https://www.futurity.org/salty-water-threatens-morocco%e2%80%99s-oases-farms/
“The flow of imported surface water onto farm fields has caused natural salts in the desert soil and underlying rock strata to dissolve and leach into local groundwater supplies,” says Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment. “Over time, the buildup of dissolved salt levels has become irreversible.”
And “fossil water” I had to look up as well. It is very old water that is trapped in the underlying strata, and does not receive any more water coming in from above. Well, that is, not until the fields above in the arid lands are irrigated.
I would suppose that the large aquifers in the USA do not have the problem with becoming saline as they are not in such arid environments, and are constantly getting recharged by rainwater. Of course many of those aquifers are being depleted as the well water extracted from them is more than the rain water. Although progress is being made with better farming techniques.
Although the huge switch over to corn to use in fuel has adversely affected the water usage. Corn needs a lot more water than most crops. But hey - less water for food people can eat, and less CO2 for plants to grow - that is probably a win-win for the NWO population control people.