Earlier quoted context omitted.
The water peddlers have successfully convinced people in places where the water is perfectly safe to drink (and tasty too) that it isn't. There are plenty of places in the world where the water isn't safe to drink but a very large portion of those is so poor the people there could not afford bottled water anyway. But for places with old water lines and all kinds of junk in the water it can make good sense to use bott…
I'm from Germany and it's almost uncanny with _some_ people. Like in, you get a glass of water (from the tap, where else?) and (some) people act like "What the hell is he doing?! Is he insane? You can't drink that!" n.b. Germany has some of the strictest regulations and accordingly the tap water is of excellent quality - everywhere.
Examples:
- Munich https://www.swm.de/privatkunden/m-wasser/qualitaet.html (the 1st PDF link)
- Nuremberg https://www.n-ergie.de/privatkunden/produkte/wasser/analysew... (click on the map, starts an interactive map, Flash unfortunately, from which the values for the four different areas they provide water for are available)
- Berlin http://www.bwb.de/content/language1/html/3255.php
I knew a woman who was a water engineer at the local waterworks. She drank nothing but tap water. You can trust a product when the engineers that made it use it.
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On the other hand, I spent some time in Russia and in Ukraine. I don't remember all the places any more, but I think the worst was in Odessa, Ukraine - an incredibly beautiful city that I fervently recommend visiting (even for someone who used to live in the Presidio in San Francisco) - where I would not even brush my teeth with the water. I had tried to use it to prepare pasta, the result was disgusting. Those pasta went into the trash.