It seems like people miss the point entirely when they worry that companies selling bottled water don’t make it clear where that water comes from. The problem isn’t really the source – the problem is that they’re selling bottled water in the first place. There’s a huge difference between water bottles that are typically bought and used once and, say, my trusty Nalgene bottle that follows me all over the place and always has fresh water in it.
Not that I’m not guilty of buying bottled items – I do occasionally indulge in a Nantucket Nectar or two, which are sold in glass, not plastic, bottles. I’ve also been known to make a hapless coffee cup go on a nice, long journey to the landfill. But there’s something about bottled water that just seems somewhat redundant. The fact that it puts tons of plastic into the waste stream is a very large drawback, but the fact that major brands may simply be purifying municipal water sources and shipping it elsewhere has its own set of problems – the energy used in bottling and transportation alone greatly outweigh just drinking from the tap in the first place. You can always get a water purification system, though these systems are problems in and of themselves.
Update (August 1, 2007): The New York Times makes a slightly stronger case on this issue than I do.