Bottled water. Need I say more?
Actually there is a case to be made for bottled water. If your tap water quality is uncertain, and your bottled water quality is reliable.
I've been in lots of circumstances where the free tap water quality was foul or suspect, and I was thankful to have to good ole bottled water available.
Years ago I spent a few months traveling around the Philippines with my wife and infant son, whom I was very cautious about what I let him eat and drink. We packed our own large water container and big pot for boiling water where ever we went. My wife's sister also traveled with us and wasn't as cautious about drinking our boiled water because she lived in the Philippines and didn't think is was necessary. Well, guess who ended up getting a severe case of Montezuma's revenge.
Oh, I forgot to mention, I've been working up north in a camp for good part of this year, and the bottled drinking water is much preferable to trucked in tap water.