Pure: unmixed with any other matter free from dust, dirt, or taint
Remember that. It's key.
Coca-Cola has admitted that its Dasani line of bottled water is nothing more than tap water put through a process called reverse-osmosis, and with "ozone" in it for sterilization. Personally, I never drink the stuff, 'cause it always makes me thirstier, which a chemistry-major friend of mine once explained is because the water molecules in Dasani have been ionized, all to get you to drink more of the stuff. Whether or not that's true, I don't know.
I am, however, intrigued by Coca-Cola's response to the allegation that selling "pure" tap water implies that all other tap water is somehow impure.
"It's just that Dasani is as pure as water can get - there are different levels of purity."
Intriguing way of putting it, since, if one looks at the dictionary definition of "pure", something which is pure must be free of all impurities. Pretty clear-cut to me. That would, of course, mean that Dasani is not pure, as it has "ozone" in it, whatever that means. Of course, "purity" levels sound nicer to public, and consumer, ears than "cleanliness" levels.
Ah, fun with semantics.