Bottled water may be chemically the same as tap water and in some cases may contain higher levels of contaminants. Researchers with the environmental working group tested 10 popular brands of water bought at grocery stores in nine states and the District of Columbia. They identified 38 pollutants in the samples... with an average eight contaminants in each brand.
While the immediate health effect on humans is not known, experts are more concerned with the fact that bottled water manufacturers are not required to notify consumers of contaminants in the water. They also say marketing may be misleading consumers to buy water that is the same as tap, at 1900 times the cost.
The researchers cited two brands in particular, Wal-Mart's Sam's Choice Brand and Giant's Acadia Brand. These samples were found to contain cancer-causing chemicals at levels above California state standards and industry recommendations. They are not releasing the names of the other brands.