When I was growing up and away from home - say, at school for instance - if I got thirsty I stopped by the school cafeteria to buy a bottle of water. NOT. We used drinking fountains.
Now that we're deep in the culture of bottled water, drinking fountains have become almost invisible. They're still around but are not used like they once were. In fact, I was at a fundraising event at a church and I noticed a fountain in the church's recreational wing. It was taped off because it was broken and they were serving bottles of water. I wondered to myself if the cost of the bottled water they purchased would pay for the repair. Simple solution but now it seems that there's the ick factor - the idea that they're germy - when it comes to water fountains so they've fallen into disuse. When they break, orobably aren't repaired.
Good news! According to this New York Times article, you're not likely to pick up any disease by drinking from a water fountain. The parts that are the biggest threat are the parts that you touch with your hands, much like doorknobs, stairway rails, etc. So, go ahead and drink that water and keep plastic out of landfill (not to mention the water that is pumped and shipped around the world, often from places facing severe drought).