Save On Gas, Drink From The Tap.

From the New Atlantis (7th item):

"Bottled water has for some time been criticized by the American Dental Association because of its lack of fluoride. Now there is reason to believe that bottled water is bad for the environment, too. According to a recent study by the Earth Policy Institute, more than 1.5 million barrels of crude oil are used to produce plastic bottles for water in the U.S. alone each year—enough oil to fuel perhaps 100,000 cars for a year. The transportation of bottled water, far less efficient than the distribution of tap water, expends even more oil. The vast majority of the bottles that hold all the water—almost 7 billion gallons each year in the U.S. alone—turn into garbage. And the concentrated extraction of water near bottling plants has reportedly caused water shortages in some regions, like Texas and the Great Lakes, which can affect farmers and fishers."