A very amusing comical sight would be, an yeckish clean mentsch pre sterilizing the water fountain before he uses it. he opens his briefcase or tallis bag and carries a little brush for scrubbing and he sprays it with lysol for disinfection.
But seriuosly, to the OP, its only appropriate if one is thirsty. according to health principles by Ramban, one should only drink when he is thirsty and as much only as the body requires.
Next, where do i remember learning that there were a group of men who were led to water to drink and the ones who would bend over like a chaya would be considered in 1 category and those who cupped their hands to bring the water up to their mouths would be in the second category. Tanach? So, depending on what category you want to be in, maybe it pays not to bend over the water fountain?