In Bangkok, it’s common knowledge that you don’t drink the tap water. Everyone carries around their plastic water bottles instead. And after a few days, you get used to walking around the city with a perpetual bottle as well.
Vancouver, Canada, where I live is a different story. Our tap water is generally quite drinkable. In fact, I’d always attributed our abundant water to the continual rain that we experience for most months out of the year. Water, water, everywhere.