This was a topic of conversation I had with my Dutch roommates back in Valencia. They wondered if tap water in Spain can be drank safely. Answer: yes. Spanish water may taste a little funny and different to Australian water but it is drinkable straight from the tap.
The same goes for Italian tap water. Perfectly safe and drinkable. So there is really no need to buy the bottled stuff which, in some places, cost about €1 per bottle.