As an ex-pat kid in India, I drank tap water at school. Throughout my career worldwide, I have - no doubt - imbibed untreated water.
I never drink aircraft "potable" (French, you know) water for reasons stated by others.
Funnily enough, Blacksheep, I used to drink filtered, unboiled water at my place on Simpang 432. I suspect the water at the RBA canteen was similar. Who is to say Sehat was the water it purported to be?