I have never been a bottled water drinker. Not originally from any concern for the environment, not because I loved our tap water (Tho here in Denver the water quality is quite high), I've never liked buy bottled water because - water? That should be free! Over the years however, I've seen an increase in people buying bottled water and a decrease in the number of public water fountains.
I've been reading "Bottled and Sold" for a class, and it takes an interesting look at the trends of taking a public product and privatizing it. Our society went from outbreaks of waterbourne diseases to clean safe public water in only a few dozen years. But now many beverage companies and trying to convince us that we must be paying more for it, and not trusting our taps.
Is Bottled Water Safer?
Who knows? No really, it's hard to say. Bottled water is loosely regulated, bottling plants are rarely inspected and testing is infrequent. Much bottled water (At least half) is simply municipal tap water. When a problem is found in bottled water recalls can take months, and are rarely publicized. City water systems however have strict regulations, test as often at 12 times per day, and when problems are found action must be taken within hours. Is tap water safer? Not necessarily, but it is more regulated and there is a lot more data available about what exactly you're drinking.
Then there's the issue of waste. Lots of it. About 850m gallons of bottled water are drank per year in the United States alone. Less than %25 of the 5.6 billion pounds of plastic bottles we use each year are recycled. The cost, in petroleum, of making a plastic bottle (this process also consumes a lot of water), filling and cooling the bottle, and transporting the bottles amounts to about a quarter of the volume of water within. So look at that bottle and imagine a quarter of it is oil. Plastics take thousands of years to break down in a landfill, and leach chemicals into the ground water all the while.
So what is the real cost of bottled water? Three to five times the cost of a equivalent volume of gasoline. Environmental degradation. A continued lack of access to clean water for the global poor. I highly recommend giving this book a read. It is quick and easy, with lots of data to back up the statements. What is your stance on bottled water?
TLDR - Buy a Nalgene, use it all the time, be happier.