In a recent investigation, the Environmental Working Group found mixtures of 38 different pollutants including bacteria, fertilizer and industrial chemicals in the 10 best selling brands of bottled water with each brand averaging 8 chemical contaminants--levels similar to tap water. Bottled water is not governed by the EPA, but is overseen by the FDA. The FDA only requires bottled water companies to test their products once a week for bacteria, while the EPA requires tap water tested 100 times a month.
There are many different kinds of bottled water:
Most people with a Reverse Osmosis Drinking Water System will take their own personal drinking water with them in the car, to work, or to the gym. But, sometimes we can't. If you must buy bottled water, such as when traveling, read the label and always choose a brand that uses reverse osmosis as part of their filtration method. Bottled water can have recalls, and you never know if it sat on a truck somewhere in the sun, but checking that it is RO water is a good start.