It's been public knowledge for some time that Pepsi-Cola bottles tap water under the Aquafina brand. The "technical" term is P.W.S., which means public water source. That's a water source that you and I pay for with taxes. Pepsi gets to take that free water, put it in a bottle, and sell it to you. So why not just bottle and drink your own?
Buy a water bottle from a great organization like SOH2O. You'll help them out, help out the environment, and save money.