The meaning of alkaline water and other terms might be confusing, so CR put together a list of words to know.

As concerns about the safety of the nation’s municipal tap water have increased, so have sales of bottled water. It’s now the nation’s top-selling bottled beverage.

And much of the marketing for that bottled water plays up the idea that it’s especially pure, and healthy in other ways, too.

Consider “alkaline” water, which has emerged as a popular health fad in recent years. Proponents claim it can hydrate you more quickly than regular water, and even help cure cancer. The problem: There’s not much solid research backing up those claims. As a 2016 review, published in BMJ, concluded: "Despite the promotion of . . . alkaline water by the media and salespeople, there is almost no actual research to either support or disprove [these ideas]."

More on Bottled Water

In fact, when it comes to making sense of all the different kinds of bottled water on the market, and their claims about purity and healthfulness, consumers are understandably confused, says Charlotte Vallaeys, senior policy analyst and food labeling expert at Consumer Reports.

In some cases, the Food and Drug Administration has defined the meanings of the terms used to describe bottled water, what it calls “standards of identity.” But those definitions may not mean what you think they do. 

Case in point: “spring” water. That term is so contentious, in fact, it’s at the heart of a potential class-action lawsuit involving Nestlé Poland Spring bottled water. The suit alleges that “not one drop” of the water qualifies as legitimate spring water, and that the company’s marketing is “a colossal fraud perpetrated against American consumers.” Nestlé denies the allegations and is appealing a judge’s ruling in March that allowed the suit to move forward.

The FDA allows manufacturers to use terms it has not yet defined, as long as that use is “truthful and not misleading.” But again, that may not mean exactly what you think it does.

For example, “alkaline” simply describes a solution with a pH above 7; those with a pH below that are acidic.

So manufacturers can use “alkaline” to describe their water as long as it really does have a pH over 7. But that doesn't mean the FDA agrees with the health claims made for alkaline water, and the agency could, in theory, crack down on companies that market their alkaline water or any other product making unproven health claims.

The International Bottled Water Association, the industry’s main lobbying group, says that bottled water is "comprehensively regulated as a food product" by the FDA and believes those protections are sufficient.

"It is vital for the safety of consumers that companies producing bottled water–whether it is treated or untreated–follow all FDA rules and regulations," the association says. "This helps ensure that mislabeled products do not reach consumers."

But Vallaeys, at CR, worries that the marketplace remains a confusing one. “Manufacturers can come up with new claims at any time,” she says, “and it's nearly impossible for consumers to tell, just by looking at the label, which are official and which are not.”

And Patty Lovera, assistant director at Food & Water Watch, a Washington, D.C., nonprofit, says that some bottled-water brands seem to be taking advantage of “concerns about purity and health and contamination” of tap water. Which, she says, makes accuracy and transparency in bottled water more important than ever.

To help in that effort, we put together a brief glossary of some common terms used to describe bottled water. Some, like spring and artesian, have FDA definitions; others, like alkaline and raw, do not. (Note that seltzers, tonics, and flavored water brands are regulated as soft drinks, not water, so are not included.)

Bottled Water Terms, Defined

  • Alkaline: Water with a pH level above 7. Some proponents say it can neutralize acid in a person’s blood and so provide a health benefit, though that is controversial. This is an industry term; the FDA doesn’t have a standard of identity.
    Example: Essentia
  • Artesian: Water from a well that taps a confined aquifer, or an underground layer of rock or sand that contains water.
    Example: Fiji Natural Artesian Water
  • Glacier Water: The FDA doesn’t have a standard of identity for this term, but Alaska has set its own definition for “glacier water” or “pure glacier water.” It must be runoff from the natural melting of a glacier, water from a stream flowing from a glacier and not diluted by another source, or the melting of glacier ice at a processing facility.
    Example: Clear Alaskan Glacial Water
  • Mineral: Water with at least 250 parts per million of dissolved solids, with a consistent amount of minerals and trace elements at its source. Bottlers cannot add additional minerals, which differentiates it from bottled water labeled as “enhanced with minerals.”
    Example: Topo Chico
  • Municipal Source: Sometimes referred to as “community water” or “public water,” “municipal source” means the water came from a tap before being treated any further. A significant percentage of bottled water is sourced this way.
    Example: Aquafina
  • Purified: Water that has been treated by various methods to remove chemicals and particulates. It can’t contain more than 10 parts per million of total dissolved solids. Purification methods include reverse osmosis (which uses pressure to push water through specialized membranes) and distillation (which involves boiling the water, capturing the steam, and condensing it back into water).
    Examples: Dasani (reverse osmosis) and Nestlé Pure Life (distilled)
  • Raw: Unfiltered, untreated water, bottled straight from the source. It’s an industry term, without an FDA standard of identity. But companies can legally sell it provided the source is approved by a local jurisdiction and the water meets federal quality standards, meaning it can’t exceed certain levels of various toxins, such as arsenic and lead.
    Example: Summit Spring
  • Sparkling Bottled Water: Water that naturally contains carbonation. It must have the same level of carbon dioxide after it has been treated, even if the gas is artificially added back. (This is different from sparkling water, artificially carbonated water, which the FDA regulates as a soft drink.)
    Example: Perrier
  • Spring: This term is the focal point of the major lawsuit against Nestlé. The FDA sets strict regulations for spring water, which it says must be “derived from an underground formation from which water flows naturally to the surface.” Crucially, it has to be collected at the spring itself, or through a borehole, or well, that taps the aquifer feeding the spring. If an external force, such as a pump, is used to move the water to the surface, it can’t change the quality and composition of the water, once it reaches the surface, by for example causing it to have more particulates or higher levels of any minerals.
    Example: Evian