Mineral water may depend on the quality of your public water supply. Violations of tap water standards are widespread in the United States, and although they are publicly reported, there is always the possibility that some contaminants will enter undetected.
Purified bottled water is regulated by the Food and Drug Administration. There is a long list of specific standards for bottled water, as well as regulations to follow for anything suitable for consumption, as water is considered as food.
Oftentimes, the bottled water you drink must also meet the standards of the country where it is packaged, as well as the various requirements of the International Association for Bottled Drinking Water. Usually unexpected bottling plant inspections are done just to make sure the water is clean as expected.
Since all of these standards and regulations must be met before leaving the bottling plant, you might think that this is the only test that is done to ensure that bottled water is clean and drinkable. However, the FDA requires that all water bottles go through a cleaning method during the filling process. FDA regulations apply to all bottled water in the United States, even imported water.
There are other standards that all water bottles must meet before they are fit for sale and consumption. It must comply with the standards of identity, quality, and good manufacturing practices. Each of the fifty countries also has its regulations for bottled water. Some countries check it manually and by machine. Others do a taste test and have to check where the water is coming from and then approve or reject it.
Most bottled water manufacturers also have strict programs to ensure the quality of their products. Some people seem to be water snobs and refuse to think about drinking any kind of water other than spring water.