I have lots of thoughts but here is how I would roll out something like this.
(1) Start this at one terminal as a test, ideally not the international terminal (where people are getting on the 12+ hour flights).
(2) Install massively more water fountains. They shouldn’t just be near the restrooms.
(3) Sell bottles that are ready to fill (not requiring a pre-wash) at the airport.
(4) Do not allow *any beverage* to be sold in plastic bottles. Why do sodas get an exemption?
People (and kids) who would otherwise drink water will now be drinking sugary stuff as a result of this policy. Because what this policy really is, is that you can’t have a plastic bottle unless you buy something with sugar in it.