Tap water is always drinkable in Italy, especially in the cities (of course, it may be a little bit different if you are talking about a cottage in the middle of nowhere). The real question is how good is that. For instance, in Rome the water has a very strong percentage of limestone and it taste doesn't very good. read more
Tap water in Milan is drinkable and safe. it undergoes 5 quality checks each day. On the dismantable filter you can find some residual from conduit flow, but since you peform regular maintenance everything is ok. read more