By Loren Merrick

The bottled water industry continues to be strong; so likewise, the NSF bottled water certification and inspection programs continue to be strong. There are over 200 companies around the world that produce more than 300 NSF certified bottled water products. The certification policies require GMP- (good manufacturing practices) and HACCP- (hazard analysis and critical control points) based audits of the bottling facility and annual testing of the products certified. In our related inspection programs for vendors, individual companies and international bottled water associations, we perform another 400 audits of bottling facilities annually outside the scope of certification.

Through this auditing activity, we at NSF have an excellent firsthand opportunity to see a large number of bottling plants and the processes they use to produce a variety of bottled water products. One thing is very clear: the water treatment industry has a significant role in the bottled water business. NSF tests and certifies all the different types of water and in North America, no matter what type of bottled water you drink, it has gone through some type of treatment.

Types of Treatment
There are some common treatments that almost all bottled water receives. One is disinfection, where ozone and UV lights are traditionally used. Bottlers with bromide in their sources that use ozone as a disinfectant have been forced to make adjustments to the ozonization process in order to limit the formation of bromate. Many bottlers use UV lights exclusively as a disinfection process, or will sometimes use UV in conjunction with the ozonization process. Disinfection is not required by the Food and Drug Administration, but is mandated by some states and is a common practice with North American bottlers.

The other treatment we often see is micro-filtration for the elimination of Cryptosporidium. Bottling plants using municipal or other sources that have a potential for the presence of Crypto use a filter conforming to NSF/ANSI Standard 53 for cyst reduction in the process to give extra assurance to regulators and consumers that there will be no Crypotosporidium in the final product. Sometimes even bottlers of protected spring waters will still use a filter conforming to NSF/ANSI Standard 53 for cyst reduction, just to make that claim.

The FDA has created standards of identity for bottled water. By examining the label, you can tell what type of water it is and have a good idea of the type of treatment(s) it has received. Here are some of the most common:

Spring Water
Spring water by FDA definition is “water derived from an underground formation from which water flows naturally to the surface of the earth…” Most consumers would expect that the spring water they purchase is ‘natural’ and has not undergone significant treatment that would change the nature or character of the water. In fact, as you will see below, changing the character of a water with reverse osmosis, distillation or similar significant treatments requires a different standard of identity. Indeed most spring water companies are proud of the composition and taste of their water. Generally the only treatment we will see in spring water is physical – sediment filters of varying degrees to remove sand or sediment.

Purified Water
Purified water is “water that has been produced by distillation, de-ionization, reverse osmosis, or other suitable processes and that meets the definition of purified water in the United States Pharmacopeia, 23d Revision, January 1, 1995…Alternately the water may be called ‘de-ionized water’ if the water has been processed by deionization, ‘distilled water’ if it is produced by distillation, or ‘reverse osmosis water’ if the water has been processed by reverse osmosis.”

For bottled water, distillation and reverse osmosis are the most common treatments for purified water. De-ionization is used in conjunction with one of the other treatments, usually reverse osmosis, rather than as a single treatment. Depending on the nature of the source water (whether well or city), softeners, sediment filters and carbon filters are often used prior to, or in conjunction with, reverse osmosis or distillation.

All bottled water must meet FDA microbiological standards, but the name purified has no relation to microbiological purity under this identity.

This is water that has undergone significant treatment. This is usually a municipal or sometimes an individual well water. If a bottled water source is a municipal water it must be identified as such on the label. However bottled water meeting the definition of purified is exempt from this clause.

Drinking water or bottled water
These are general terms that can apply to any bottled water suitable for human consumption. This could include purified products that can use the names purified drinking water, distilled drinking water etc. or simply drinking water. The term drinking water when used in North America, particularly with water treatment companies that produce and sell bottled water, is water that has been purified by distillation or reverse osmosis and had a small amount of minerals (usually sodium, potassium and magnesium) added back for taste. There are also some drinking waters that are well water and like spring water, only use physical filtration. Alternately, occasionally a municipal source is treated with a sediment filter or an activated carbon filter, then disinfected and sold as drinking water. Usually this is done in an area with poor tasting city water or municipal water that has periodic fluctuations of volatile organic substances (VOCs). While the treatment is not significant by definition, the final product is usually an aesthetic improvement over the source.

There are other, less common standards of identity. Mineral water is natural water with varying degrees of total dissolved solids. Well or spring water with over 250 ppm TDS may be labeled mineral water; water with less than 500 ppm TDS can use the statement low mineral content, and those above 1500 ppm TDS, may use the statement high mineral content. Treatment for mineral waters would be similar to spring waters – in fact, a spring may produce mineral water. The nature of the water cannot be changed, so the only treatment normally utilized is physical filtration.

These Standards of Identity are summarized in Table 1.

The bottled water industry and the water treatment industry are forever joined. Regardless of which of the many types of bottled water a bottler produces, the product goes through some type of treatment. The labels always give an explanation – if you understand the standards of identity and the treatments commonly used.

About the author
Loren Merrick is General Manager of the Bottled Water Certification Program with NSF International and a certified Environmental Health Specialist. A former bottled water plant manager, Loren has been with NSF since 1992, managing the bottled water program since 2001. He has visited over 300 different bottling facilities around the world. He can be reached at 734-913-5762 or


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