We drink, bathe, cook and clean with it. But how much do we really know about the water that flows out of our faucets? Some regions fare better than others when it comes to contaminants, but lead, bacteria and nitrates can still make their way into water supplies. And recent debates on the potential negative impact of hydraulic fracturing (one way of mining oil and gas trapped deep underground) have brought even more attention to what's reaching our water supply. So before drinking up, let's take a closer look at what's on tap.