Having a supply of potable water at festivals has long been something I've organized with a 5 gallon dispenser, refilled regularly and - imagine that - PAPER cups! There is absolutely NO reason why anyone has to have a plastic cup to drink water. I tend to thrive on iced tea in the summer, and carry a bottle of it with me, keep frozen spares on hand for long days.

I don't think expecting people to supply their own bottle for water is outrageous, if one has facilities for free refills on site.

Joanne in Cleveland (where it gets terrible hot and muggy during festival season)