Banning Bottled Water
It's limited to places that have other sources of water (fountains) and thus, at first blush, seems like a grand idea. People will still be able to get water, and they won't have to pay for it, and it won't come in a bunch of waste plastic.
A second thought, though, reveals the unmitigated dumb of it. Water fountains? That's the alternative?
Water fountains can't be taken to your seat. Water fountains don't give you 500ml of water at a time. Water fountains aren't particularly hygienic given the way people tend to use them. The water in water fountains is very often nasty and warm.
If I'm buying lunch and I can't buy a bottle of water, I'm not going to think 'well, let me run off and find a water fountain that I may or may not actually be willing to drink out of once I see it', I'm going to buy a diet coke.
The end result of banning bottled water sales isn't going to be less plastic, it's going to be more caffeine, and, since most people don't drink diet coke, more calories.