A blog regular sends a tip about a story in the NY Times about water served in restaurants. He writes:
Some restaurants, especially in California, are trying to eliminate the environmentally unfriendly bottled water and ("Drink Local") setting up their own sparkling water systems and filtering their tap water. To heck with the profits, they say, of selling a dollar's worth of bottled water for up to $8.
I don't think I have ever, ever bought a single bottle of water. (I'll take my bow now, thank you very much.) I have perhaps drunk one bottle (an Arkansas one) but no more than that. Little Rock tap water, especially when cold, is just as good if not better (knock on wood to prevent the likes of Jay DeHaven and Deltic Timber). I reckon most Arkansas restaurants, being run by good, honest, down-home folks, still serve tap water (for free!) if a diner wants a glass of water and don't stock bottled water. I have seen bottled water in lots of bars, however. I am certainly not going to drink bottled water in a bar unless it's been infused with hops.
If the water is still, I'll always take it from the tap. I like having sparkling water with food. But I rarely do it in the U.S. because the prices are confiscatory. I always do it in Europe, where the prices are far more reasonable, maybe $2 for a big jug in even fairly nice places.