How to Read a Bottled Water Label
The word on the front of a water bottle isn't marketing — most of them have legal definitions. In the U.S. the FDA regulates bottled water as a food and defines what can be called spring, purified, mineral or artesian water. Once you know the terms, a label tells you where the water came from and what was done to it.
What do purified, spring, artesian and mineral water mean?
| On the label | What it means |
|---|---|
| Purified | Treated — by reverse osmosis, distillation, deionization or similar — until it meets a strict purity standard. Can start from any source, including a city supply. |
| Spring | From an underground source that flows naturally to the surface, collected at the spring or through a borehole into the same source. |
| Artesian | From a well that taps a confined aquifer, where the water is under enough pressure to rise above the top of the aquifer. |
| Mineral | From a protected underground source with at least 250 parts per million of dissolved minerals, all of them natural — none may be added. |
| Well | From a hole drilled or bored into an aquifer. |
| Sparkling | Naturally carbonated at the source; carbon dioxide lost in treatment may be put back to the original level. |
Words like "natural", "pure" or "glacier" outside this list don't have the same legal weight. The terms in the table do. For a side-by-side on taste and use, see spring vs purified vs alkaline.
Is alkaline an official type of bottled water?
"Alkaline" isn't one of the FDA's names — it describes the pH, where 7 is neutral and anything above is alkaline. Most alkaline waters sit between 8 and 9.5, and a label that says alkaline should give the number. Alkaid's is 9.5. What that number means.
What does TDS mean on a water label?
TDS — total dissolved solids — is the amount of minerals dissolved in the water, given in parts per million (the same as milligrams per litre). Purified water starts near zero, which tastes flat, so many brands add a small, measured blend back. When they do, the label says "minerals added for taste" and the ingredients name them. That's how Alkaid is made: purified first, minerals added back.
How can you tell where bottled water comes from?
If the water started as a public supply and isn't treated enough to be called purified, the label has to say "from a community water system" or "from a municipal source". Spring and mineral waters name their source. Purified water doesn't have to, because the treatment is the point.
Does bottled water expire?
U.S. labels give fluid ounces and millilitres: a 16.9 fl oz bottle is 500 mL, a 33.8 fl oz bottle is one litre. Bottled water has no federally required expiration date; any date on the bottle is the bottler's, for stock rotation and taste. Keep cases somewhere cool, out of direct sun and away from cleaning products or fuel.
Sources
- U.S. Food and Drug Administration (Code of Federal Regulations). 21 CFR 165.110 — Bottled water, 2026.
Questions people ask
Is alkaline an official bottled-water type?
No. The FDA defines names like purified, spring, artesian and mineral water. "Alkaline" describes the pH, so a label that uses it should give the number.
Does bottled water expire?
There's no federal requirement for an expiration date on bottled water. A date on the bottle is the bottler's, usually for stock rotation and best taste. Store it cool and out of the sun.
What does "from a municipal source" mean?
The water started as a public water supply. If it isn't then treated enough to be called purified, the FDA requires the label to say where it came from.
Is mineral water the same as water with minerals added?
No. Mineral water has to carry its minerals naturally from the source, and nothing can be added. Purified water with minerals added for taste is a different product, and the label should say so.