70 percent of bottled-water samples exceed regulatory standards for a certain type of bacteria.
Researchers at C-crest Laboratories Inc. in Canada arrived at that percentage by testing the most popular brands of bottled water on the market. (They don't call out the brands by name in their findings.) The United States Pharmacopeia, which sets standards for tap-water quality, states that water shouldn't contain more than 500 units of heterotrophic bacteria per milliliter. One of the bottled brands tested at 80,000 units.
Heterotrophic bacteria gets its energy from carbon. Not much is known about the way heterotrophic bacteria affects humans, and some scientists suspect it doesn't pose much of a threat. However, it is associated with the E. coli bacteria; high levels of heterotrophic bacteria could signal that the water has other, more dangerous contaminants.
Something to think about, if you weren't already turned off by spending your hard-earned money on something that literally falls from the sky.