> You cannot legally demand what physically is not there.

But you can demand what is provided to you by public utility isn't knowingly and secretly poisoned with a neurotoxin.

US has a lot of underground water, that is starting to run a bit low atm, but it's not like they are on desert world. The reason there is no political will to ensure access to water in US, is because its good way to make money, and any legal guarantees as to quality/safety of the water would unreasonably lower investors' return