This isn't really new. There have been cases where the source of the water has been suspect (the one I remember was Cathay but I'm pretty sure there are/were others). The tanks holding the potable water are not always (often) flushed either... better if you can get water in the terminal and suppliment it with juice or other liquids onboard if you're concerned. Any water for coffee or tea, please at least make it hot enough to kill any pathogens.