Tap water does have its issues too. Although regulated by the EPA and the FDA, there can still be several problems. They cannot regulate the water all the way into people's homes. As the water makes its way from the pipes into your home, lead can be added through corrison in the pipes. This is especially harmful for young children and pregnant mothers. Another point of concern is that of chlorine. Chlorine is added to kill biological water contaminants; however, chlorine is also a cause of bladder cancer, rectal cancer, asthma, and now, breast cancer.
33% of Gastro Intestinal Illnesses can be traced back to tainted water.