Perhaps it stems from the same thing that causes many people to believe that they can't drink water straight out of a river or lake without first purifying it, despite that many of us grew up in a time where we swallowed plenty of the stuff long before environmental regulations went into effect...or we all grew up drinking water straight out of the green garden hose, but we all carry the special white hose to fill our tanks...
I don't know....just like I didn't know if there was anything that would be a cause for concern in a tank that may have had water in it for 6 months or 6 years...
As for drinking it..if I filled up at home, I wouldn't hesitate to drink it, but after years of living on a well, I've found that I can't stand the taste of most city tap water any more, so having bottled water on board is pretty likely anyways.
