There are basically three types of bottled water.
Natural Mineral Water must come from a specified underground source, which is protected from pollution and registered with the authorities. It must meet tight microbiological standards, be regularly tested, receive no treatment other than filtration or carbonation and be bottled at source. It must also have a stable chemical composition. Natural Mineral Waters are the highest quality bottled waters.
Spring Water must come from a single underground source. It must also be bottled at source and comply with microbiological and chemical standards. The only permitted treatments are carbonation and filtration. Spring water does not have to be stable in composition and does not have to be officially recognised prior to marketing.
Table Water basically any water in a bottle. It can come from more than one source, or not from an underground source at all. Bottled table waters may even come from the public mains or be transported from the source to the bottling plant in tankers. The water may be treated to change its chemical composition or to reduce the number of microbes. Some companies even add mineral salts to the water to taste like spa water.
Natural Mineral Water and Spring Water enter the bottling plant direct from the source through stainless steel pipes. Dedicated filling machinery in special bottling rooms is used. The bottles are capped, labelled and packed in boxes or shrink-wrapped in plastic and loaded on to pallets. Bottles can be made of glass or special types of plastic that do not affect the odour or taste of the water. Both bottles and caps should be sterile. The whole bottling process has to conform to very high hygiene standards and good practice in order to protect the water from contamination. Regular quality checks are carried out at every stage.
Table waters enter the bottling plant either through the mains or in a tanker. Different waters may be blended and various treatments applied such as filtration, ozonation, UV radiation, reverse osmosis or precipitation before they are bottled under similar conditions to Natural Mineral and Spring Waters.