I do drink bottled water quite simply because it tastes much better. My preference in regards to taste of water is: Poland spring .5L bottles >
Poland spring 5Gal > Fiji, Evian, etc > filtered water > unfiltered tap.
On the other hand I don't have a car so I don't create co2 by driving one and I don't fly airplane for vacations, and I don't eat meat which is more costly environmentally than vegetarian food. So, it's a matter of comparing the total co2 and other pollution that your lifestyle leads to. What is the co2 cost of one 4-hour car ride vs. shipment of spring water first by train and then by truck? What is the cost of one airplane roundtrip compared to shipment of bottled water from Poland Springs to NYC?
You also have to consider indirect costs. Many people will buy a bottle of water instead of buying some other type of bottled drink. Other drinks are more co2-costly because they still contain water that has to be shipped, and other ingredients have to be processed, too.
Another way to look at indirect costs is that drinking water instead of other beverages can improve health, and health services are co2-costly as well, because hospitals have to be built, doctors and nurses have to drive to medical schools, then drive to their place of work, medical equipment has to be manufactured. If people have a choice of drinking the best tasting bottled water vs. tap water, they may choose to drink something else entirely if tap water does not taste good, out of misguided care for environment, and end up doing far greater environmental damage.
I don't see why shipping bottled water has to be so costly. It should be shipped by train from source and bottled in every large city, and then shipped in diesel trucks. Certainly more costly than tap water but less costly than pretty much any other drink.
I only drink water and tea made with spring water
- I want my water to taste good. Tap and filtered water most definitely do not.
I'll agree, though, that buying Fiji and Evian is silly, they taste worse than Poland Spring (especially Evian!), and are more costly to ship. But railing against them is pointless without some hard numbers comparing their use vs. other common co2-heavy expenses, e.g. manufacture of a car, of home electronics, driving a car, raising cattle for meat, running an air conditioner, heating, etc etc.