Whether these bottles really contain pure water from springs, is difficult to say, as several manufacturers market purified water in the guise of spring water. Not many people give it a thought, but understanding the difference between spring water and purified water can be of great help.
Natural Spring Water
Spring water, as its name suggests, is water which flows naturally to the surface from some protected underground source on the Earth. As per the FDA guidelines, water can be marketed as spring water only when it is collected from the source of the spring in its pure form.
Furthermore, these guidelines clearly state that spring water can only be collected from the site. It can either be collected directly from the spring, or by tapping the underground source by means of a bore-hole. It should retain the taste, qualities, and physical properties that it has when it surfaces.
Purified water, on the other hand, is water which is subjected to some physical purification process to make it safe for drinking by getting rid of bacteria in it. As in the case of spring water, the source of water in not given importance here.
Even the water that is collected from municipal tap, but subjected to some purification process before being bottled can be marketed as purified water. The different methods used to purify water are distillation, deionization, reverse osmosis, etc.
It is mostly labeled as 'purified drinking water' and, at times, is also labeled with reference to the process by which it is purified, like 'distilled water' if it is subjected to distillation.
Natural Spring Water Vs. Purified Water
The differences between these two start right from their point of origin. While true spring water has to be directly collected from a spring, purified water can be from any source, including a river, stream, or a spring.
While the origin is given utmost importance in the case of spring water, it is the treatment of water which is considered more important when it comes to purified water. As far as safety is concerned, both are safe, as it is mandatory for manufacturers to stick to certain guidelines laid by the FDA.
That being said, the brand name does come into picture here, as the chances of companies resorting to unprotected springs (in case of spring water) and cheap purification techniques (in case of purified water) cannot be ruled out.
If you compare the two for their health benefits, you will realize that the latter is more beneficial owing to its mineral content. In terms of cost, spring water is a bit more costly than purified water, which explains why the latter is more popular when it comes to sale.
In the end, whether to choose spring water or purified water entirely depends on the one's taste, safety of water and the cost. While some are comfortable with the fact that spring water is healthy, others prefer the taste of purified water. At the same time, there are people who can't differentiate between two and hence, go by what they read on the label.