Unless they use salt water they draw from the same supply of groundwater or surface water as drinking water.
Drinking water is usually surface water or groundwater pumped from a lake/river or a drilled hole in the ground passed through a filter, an UV light to kill bacteria, and possibly some chemicals added to get the correct pH.
The limiting factor for how much drinking water you can make is how much you can pump out of the ground/lake before it dries up.




Has any of the trends so far required a lot of effort to do?