From what I was reading at school in a public health publication, tap water is, as a general rule, much safer if it comes from a municipal water supply because in the United States, municipal water is filtered and treated and is required by law to be regularly sampled, tested and inspected. Bottled water, on the other hand, is completely unregulated. There's no telling what's in those bottles, and there's no oversight to make sure it's safe and clean. Interestingly, although the water itself is generally safe to drink, water from public drinking fountains is notoriously contaminated from saliva- and skin-borne bacteria and viruses because people put their faces and mouths down too close to the spigots. There've been several tests of public water fountains in the Dallas area, and the results are never good. (News stations here in Dallas like to do stories on this subject during ratings-sweeps periods.)

I drink water that originates from our municipal water supply, and it's filtered through the filter in my refrigerator before it comes out the front of the refrigerator door. I like the way that water tastes better than any other I've tried.