One fact about artesian water is that it is under a lot of pressure before manufacturers bottle it. Artesian water held between layers of poorly permeable rock is under intense pressure that forces it to the surface through a tapped well. This pressure is sometimes high enough to force water the height of multistory buildings without a pump. The French city of Artois, home of the best-known artesian wells in the Middle Ages, is how artesian water got its name.
Bottled before it comes into contact with the air or any possible pollutants, Artesian water has no special medicinal qualities and differs from spring or mineral water only in taste and extraction methods. It is naturally filtered but is not held to any higher safety standards in the United States than tap water. Both, when properly regulated, are equally safe and healthy to drink.
There are taste differences between different brands of bottled artesian water, as well, depending on the source and the mineral content. Some artesian water is pure, and some is heavily mineralized.
Artesian water is held in layers of subsurface rock known as an aquifer. Wells that extract the water are called artesian wells only if the water in them is under enough pressure to rise higher than the top of the aquifer. Artesian water in the United States mainly comes from the Great Plains, the Atlantic Coastal Plan and central California.