FDA has established a bottled water Standard of Identity to define the several different types of bottled water based on specific characteristics of the product. Bottled water products are normally categorized according to the source of the water and the method that the bottler uses to treat it.
Bottlers are required to disinfect their source water, usually done with ozone or ultraviolet technologies, or obtain it from an approved potable water source, such as a municipal water supply. Some bottling companies choose to further treat their bottled water products through processes such as filtration, reverse osmosis, or distillation. More information about the different types of bottled water is available on the NSF International web site.