This report from the National Post that the Toronto and Ottawa-Carleton school boards are considering banning the sale of bottled water in their elementary and secondary schools is a sign that governments are going way too far in encroaching on individual prerogative. The nanny state is apparently expanding to the point where it will make it difficult to choose one's own water source.
Let people choose whether or not they want to purchase bottled water, rather than taking away the option. Some people, myself included, prefer the taste of bottled water over tap water (I like the taste of Dasani water the best), and we should not be forced to drink tap water for the school boards to make an irritating environmental statement.
If students find the bottled water too expensive, of poor taste, or environmentally problematic, then those students can drink tap water. I'll stick with the bottle though.