At Vanderbilt, do most students drink out of reusable water bottles or disposable ones? Are there lots of water fountains at Vandy to refill reusable bottles? Thanks! 
Yup, there are lots of water fountains. At least one on each dorm floor. I use reusable bottles.
In almost every building there is a NEW water fountain that is specifically designed to use with reusable water bottles. There would be no point to use disposable water bottles when you are on campus.