I dropped by a restaurant last week myself for a breakfast since my hunger may not last the long trip to an appointment. As I ordered food, I was also offered drinks which I refused. And then the server asked if I would have house water or bottled water. That floored me. What is the difference between the two? Well, the bottled water is what we know as mineral or purified water while The House water is what they have in their dispenser. So what's the catch? The server said, "nothing, they are just the same." What the heck. I was glad that I was not so quick in ordering bottled water which costs 50 cents in those kind of restaurants.
Well, I'd still go for a bottled water in such a context. Yes, it's costly than the house water. But, there can be chances for contamination as they use their hands to serve the water. The water, itself, may not have been properly filtered, purified, or otherwise hygienic. I wouldn't take a risk and go for a bottle of mineral water for at least the purity is guaranteed, unless it's a star hotel and they keep things nice and tight.
For me it would depend on what I thought of the restaurant. Most of the time I'm too paranoid to trust that they arent just using water straight out of the faucet but for most big brand restaurants I know they wouldn't risk it so I am more comfortable with just ordering their house water. If I were to order bottled water though I think I would just go with a soda since they are roughly the same price and I feel as though I'd get much more value with a sweet drink at least. That is unless I feel I am drinking too much sweet drinks and I feel the need to cut down and then I will just order the bottled water.
This does depend on the kind of establishment, as some do use purified water and others just do jugs of tap water with ice. I know, because I have seen it in hotels when I used to organize conferences, and they would still charge for jugs of iced tap water.
@Theo: Spot on! We just gotta take their word for it. We simply can't take chances with drinking water as water-borne diseases are too dangerous and life threatening. The cost of treatment and hospitalization could be umpteen times more expensive than a bottle of packaged water. Unless, you are sure of what you are doing, you can't afford to take chances with drinking water. Just my 2cents though. Apologies to all. Never meant to offend anyone.
I used to ask why they charged for it, and they said it was the cost of using the jugs and preparing it! It's not worth the risk, but some upmarket places did have filtered water that they decanted into glass bottles. That is usually safe. I have seen in some places they have a water filter jug too that the servers use, and that's fine, but not open jugs with ice to keep it cool. I've had tummy bugs and it really is not worth the risk after 2 weeks of being ill. The cost could have been death...