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.
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.
The issue is that ozone purification cleans the water at the source, but it's free to pick up contamination in the pipes as it makes its way to the tap; chlorination works right up until the water is drunk. The downside is that chlorinated water does not taste great.
If one has a good pipe system, the ozonated water is fine. If there's any worry, though, chlorinated is safer. I'm not surprised that a military base would choose the safer alternative: no-one ever got fired for ensuring that the water is safe to drink.
n.b. Germany has some of the strictest regulations and accordingly the tap water is of excellent quality - everywhere.