Some of those big water bottle delivery services have reputation of delivering poor quality water (not pure distilled etc, as advertised) also. In my last place, I started buying big jugs of cest’bon or whatever it is instead, since the delivered water kept having little floaty things inside when inspected upon placing a new container on top of the water machine.
I guess the bottom line is either way you go, there are potential risks.
Pollution is a big issue, and Chengdu used to be a lot better – lately it’s just disgusting, dusty dirty shit air that’s leaving layers of dust every day my windows/doors are open. Everyone can agree that Chengdu’s air quality is shit – maybe a large part of that most recently is the massive amounts of road/subway construction sprawling city wide..