I came across this article from the Environmental Working Group (EWG) where they tested 10 major brands of bottled water and found common chemical pollutants present in some samples. The report claims that bottled water from the Walmart brand (Sam's Choice) and Giant Foods' Acadia brand contained trihalomethanes, a disinfectant byproduct, in levels that exceed California standards for safe drinking water. The bottles tested came from manufacturing plants from several states, but some states tested far better than others. So what does it all mean?
First, you should know that the state of California has stricter standards for public drinking water than the rest of the country. This means that a chemical can violate the legal limit for a contaminant in the state of California and still be legal in another state. California also enforces stricter standards than the FDA when it comes to bottled water, which says more about the lack of action from the FDA than it does the state of California. Water that is bottled outside of California doesn't have to meet the state's safety standards to be sold there. Though, personally, when it comes to drinking water I want the best water quality possible.
According to the EWG study Walmart representatives acknowledged that Las Vegas tap water was the source for some of their bottled water. This easily explains how disinfection byproducts, like trihalomethanes, were found in their bottled water. Trihalomethanes are the result of a naturally occurring chemical reaction between chlorine and waterborne contaminants, so it isn't unusual to find the contaminant in tap water that is disinfected with chlorine. Of course, the marketing of bottled water products leads you to believe that the water is more than just ordinary tap water.
If you look at the label on bottled water you will usually see a lot of 0's. 0 grams of sugar, 0 grams of fat, etc. The bottled water industry uses this tactic to make you think their drinking water is more "pure" and safer than tap water. Trihalomethanes are not safe to drink and at higher concentrations have been linked to cancer and birth defects. Not all bottled water is created equal. The EWG believes that the FDA needs to crack down on the misleading labeling and marketing of bottled water as a safer way to drink water. As the article points out "Consumers could have obtained much better drinking water simply by installing a home tap water filter at a fraction of the bottled water cost."
At the end of the day the message is to make sure you know what's in your water. Take control of your drinking water quality and consider filtering and bottling your own water (preferably in a reusable bottle). At least this way you can be sure exactly what you are putting in your body when you take that first refreshing sip of water.