Don't know about about other countries but where I live obtaining and selling spring and mineral water is nothing unusual. There are laws that regulate it to ensure it's safe for consumption.(link with english translation on the right side) https://likumi.lv/ta/id/278817-noteikumi-par-dabigo-mineralu...
Pay attention to point 16:
> 16. Any disinfection treatment by whatever means and the addition of bacteriostatic elements or any other treatment likely to change the viable colony count of the natural mineral water is prohibited for natural mineral water and spring water.
In my country (Brazil) buying bottled mineral water is also common. But I don't know whether it comes directly from the spring, or is passed through a filter first. We learn from childhood that one must only drink filtered or boiled water, so I won't be surprised if there's a filter involved.
Tap water is fine in most cities here but many people just prefer the taste. Not many buy it for drinking at home but it is very common in water coolers at offices.
Pay attention to point 16:
> 16. Any disinfection treatment by whatever means and the addition of bacteriostatic elements or any other treatment likely to change the viable colony count of the natural mineral water is prohibited for natural mineral water and spring water.