Potable water is kind of mandated by the government. I mean, that doesn't GUARANTEE your water will be totally safe to drink, but I'm pretty sure that at least the USA's tap water is considered to be some the safest water you can get. If you want it a little bit more filtered, more power to you, but I'll just say I used to drink water from garden hoses when I was a kid living in Texas (not by necessity, just because I was a kid), and I've swallowed more than a few mouthfuls of public poolwater on accident throughout my life. I don't think straight tap water can be any worse for me than that. I think anyone who claims to "feel sick" every time after drinking tap water is just suffering a placebo effect. And bottled water is just tap water in bottles.