In blind taste tests, most people can't tell the difference between bottled and tap.
The crystal-clear mountain springs, sparkling glaciers, and pristine landscapes pictured on bottles and in ads must help sell bottled water, judging by the numbers.
The average American drinks more than 24 gallons of bottled water each year -- more than milk, coffee, or beer. Only soda is more popular, but bottled water is catching up, its sales more than doubling in the U.S. during the past decade, totaling nearly $10 billion last year.
But look behind the pictures and names. Glacier Clear Water, for example, doesn't come from a glacial source, but a municipal water supply -- tap water, in other words -- in Tennessee. That might look like Mt. Everest on the bottle of Everest Water, but inside is treated municipal water from somewhere in Texas.
The story is similar for Aquafina and Dasani. Even when bottled water is not tap water, the rules are loose enough that "spring" water may actually come from wells or aquifers. Some bottled waters do come from mountain springs or glacial sources, but they are a minority.
Many people, suspicious of tap water, buy bottled because they think it's more natural, purer, more healthful and better tasting. But the facts usually prove otherwise.
Bursting the bubble
The source. It's not a negative that many bottled waters come from municipal water supplies -- except that consumers may not realize they're spending $5 or $10 a week on bottled tap water. Municipal supplies are excellent sources of drinking water, and Americans (along with Canadians and people in most other industrialized nations) have a right to be proud of their public water systems.
Who is watching. Tap water is strictly regulated by the Environmental Protection Agency (EPA) and monitored by municipal suppliers. Bottled water, in contrast, is regulated by the Food and Drug Administration (FDA) only if it is shipped across state lines or is imported. In some ways the FDA standards are weaker than the EPA's, and its testing far less frequent.
In any case, most bottled water is packaged and sold within one state, so it's subject only to state regulation, which varies greatly -- and in some states is nonexistent. California has some of the strictest regulations. Most bottlers belong to the International Bottled Water Association, a trade group that has its own guidelines, though it's hard to know how good such self-regulation is.
What researchers have found. Several studies have found that while most bottled water is of high quality, some is out of line with the strict standards for tap water.
A few years ago, for instance, a study comparing bottled waters with tap water from Cleveland found that one-quarter of the bottled waters had significantly higher bacterial counts than tap water. This doesn't mean that the bottled waters contained enough bacteria to cause illness, but enough to raise a red flag -- and these findings certainly dispel the myth of the purity of bottled water.
What taste tests show. In blind taste tests, most people can't tell the difference between bottled and tap. Sometimes plastic bottles can impart a slight plastic taste, leading some people to worry about chemical residues. The plastic bottles are safe, however.
Nutritional benefits? Only "mineral water" (a tiny part of the bottled-water business) has extra nutrients, and even these minerals don't add up to much. Tap water does usually have one important nutrient seldom found in the bottles -- fluoride, which is added to most supplies to reduce cavities in children. Bottlers generally filter out the fluoride from municipal water.
The environment. If you care about conservation of resources, tap water is by far the better choice. More than a million tons of plastic is used every year to make water bottles. It takes lots of energy to make, ship, and refrigerate the bottles -- and energy production creates air pollution. Most of the plastic, which is not biodegradable, ends up clogging our landfills.
When bottled water is a good idea
In some places, and at some times, bottled water is safer than tap -- notably in the developing world, where the water supply is risky. Moreover, millions of Americans and Canadians get their water from unregulated private wells, which are more likely to be contaminated.
On rare occasions water from a public utility temporarily becomes unsafe, in which case the utility must by law notify consumers and tell them what to do. (This may happen after flooding, as was seen after hurricane Katrina.)
If your tap water is contaminated, however, your best long-term option is to filter it -- that's more convenient and cheaper than bottled water. The same is true if you know your water is high in lead (from plumbing pipes) or if your tap water simply has an off flavor or smell.
If you have questions about your drinking water or water filters, consult the Environmental Protection Agency, Natural Resources Defense Council; or NSF International. Or go to the Subscriber's Corner.