Pepsi-co and Coca-cola are both guilty of this. That's why the bottles are labeled as "purified" water. They were forced to do that a few years back due to false advertising if I'm not mistaken.
As for the popularity of bottled water...
I think part of the problem is that bottled water has become associated with "health" products. People are fooled into believing that tap water contains "harmful impurities." When really, Aquafina and Dasani are probably composed of water that has been recycled from other production processes. Big companies like Pepsi-co and Coca-Cola don't tend to let anything go to waste.
That is not to say bottled water is without merit. Natural disasters can break water mains, making tap water unsafe to drink. If you have no means to boil water to kill bacteria (i.e. electricity,) then bottled water is the way to go.
There's also the matter of taste. Some people prefer bottled water over tap water. For me, the taste of tap water varies from state-to-state and with bottled water from brand-to-brand. Generally, I prefer bottled spring water over tap water. I'm also a sucker for highly-oxygenated water and glass bottles rather than plastic bottles. Still, water is water and since I need it to survive, I'm perfectly content to drink from tap water on a regular basis. Hell, I drank tap water from the Bahamas!
And for anyone still concerned about the safety of drinking tap water in the USA, I shall refer you to these three links I found by searching for "tap water quality."
EPA Ground Water & Drinking Water FAQNRDC: Tap Water Quality and Safety FAQEWG's National Tap Water Quality DatabaseOh and just to show a bit of Italian pride...
New York has the best tap water and Italy has the best spring water. ;p
