EPA Bottled Water Health Series Booklet: Tap water or Bottle water?
Bottled water basics
Bottled water is the fastest growing drink choice in the United States, and Americans spend billions of dollars each year to buy it (Beverage Marketing Corporation, 2004) Some people drink bottled water as an alternative to other beverages; others drink it because they prefer its taste or think it is safer than their tap water. Whether it travels through a pipe to your home or comes packaged in a bottle, safe drinking water is essential to good health. All our drinking water comes from similar sources, either from sources we can see, such as rivers and lakes, or from sources we can’t see, such as underground aquifers. In the same way that tap water’s taste and quality may vary from place to place, so too does bottled water’s taste and quality vary among and even within brands. The taste and quality of both bottled water and tap water depend on the source and quality of the water, including its natural mineral content and how, or if, the water is treated.
Drinking water (both bottled and tap) can reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that the water poses a health risk. For example, minerals such as magnesium and calcium give water a distinctive flavor, and are essential to the body. At high levels, however, these and other contaminants, such as pesticides or microbes from human wastes, can cause adverse effects or illness. To make sure that all water is safe to drink, the U.S. Environmental Protection Agency (EPA) and the U.S. Food and Drug Administration (FDA) set drinking water standards. EPA sets standards for tap water provided by public water suppliers; FDA sets standards for bottled water based on EPA standards.
Bottled water and tap water are both safe to drink if they meet these standards, although people with severely weakened immune systems or other specific health conditions may wish to further treat their water at home or purchase high quality bottled water.
FDA regulates bottled water as a packaged food under the Federal Food, Drug and Cosmetic Act and has established standards of identity and quality for bottled water. FDA has also established good manufacturing practice requirements for processing and bottling drinking water.
EPA encourages all Americans to learn more about the quality of their drinking water, both tap water and bottled water, before deciding whether to drink tap water, bottled water, or both. If your water comes from a public water system, the best way to learn more about tap water is to read your water supplier’s annual water quality report. If your water comes from a household well, EPA recommends testing the water regularly for bacteria, nitrates, and other contaminants. The best way to learn more about bottled water is to read its label, or contact the producer directly. Taste considerations Many people prefer bottled water because of its taste. The taste of all water has to do with the way it is treated and the quality of its source, including its natural mineral content. Most bottled water comes from a ground water source, where water quality varies less from day to day, or is treated and immediately bottled. Bottled water from a dedicated source or plant may have a more consistent taste than tap water, which mostly comes from surface sources and must travel through pipes to reach homes.
One of the key taste differences between tap water and bottled water is due to how the water is disinfected. Tap water may be disinfected with chlorine, chloramine, ozone, or ultraviolet light to kill disease-causing germs. Water systems use these disinfectants chlorine and chloramine because they are effective and inexpensive, and they continue to disinfect as water travels through pipes to homes and businesses. Bottled water that is disinfected is typically disinfected using ozone or other technologies such as ultraviolet light or chlorine dioxide. Ozone is preferred by bottlers, though it is more expensive than chlorine, because it does not leave a taste and because bottlers do not need to worry about maintaining disinfectant in water sealed in a container. Untreated water, whether from a bottle or from a tap, will have the characteristic taste of its source.
Type of water and source: Bottlers use standard identifiers, prescribed by FDA regulations, to describe their water (Bottled water terms, pgs 4 and 5), but the meanings may be different than you expect. These terms refer to both the geological sources of the water and the treatment methods applied to the water. The terms don’t necessarily describe the geographic location of the source or determine its quality. For instance, “spring water” can be collected at the point where water flows naturally to the earth’s surface or from a borehole that taps into the underground source. Other terms used on the label about the source, such as “glacier water” or “mountain water,” are not regulated standards of identity and may not indicate that the water is necessarily from a pristine area. Likewise, the term, “purified,” refers to processes that remove chemicals and pathogens. “Purified water” is not necessarily free of microbes – though it may be. Advice for people with severely compromised immune systems Some people may wish to take special precautions with the water they drink. In particular, people with immune systems that are weakened by AIDS, chemotherapy or transplant medications are more vulnerable to microbial contaminants in drinking water such as Cryptosporidium. Cryptosporidium is a microscopic parasite that lives in the intestine of infected animals and humans. It passes in the stool in its dormant oocyst form. The oocyst is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it very resistant to chlorine-based disinfectants. It occurs mainly in surface water sources, such as lakes, streams and rivers. In healthy adults, Cryptosporidium can cause illness, but for people with weakened immune systems, it can cause severe illness and even death. Those who wish to take extra measures to avoid waterborne.
cryptosporidiosis can bring their drinking water to a boil for a full minute. Boiling water is the most effective way of killing Cryptosporidium. As an alternative to boiling water, people may take the following measures: Bottled Water Terms The following terms are frequently used on bottled water labels to describe the water’s characteristics, sources, and methods of treatment.
Artesian water, ground water, spring water, well water – water from an underground aquifer which may or may not be treated. Well water and artesian water are tapped through a well. Spring water is collected as it flows to the surface or via a borehole. Ground water can be either.
Distilled water – steam from boiling water is recondensed and bottled. Distilling water kills microbes and removes water’s natural minerals, giving it a flat taste. Drinking water – water intended for human consumption and sealed in bottles or other containers with no ingredients except that it may optionally contain safe and suitable disinfectants. Fluoride may be added within limitations set in the bottled water quality standards. Mineral water – Ground water that naturally contains 250 or more parts per million of total dissolved solids. Purified water – water that originates from any source but has been treated to meet the U.S. Pharmacopeia definition of purified water. Purified water is essentially free of all chemicals (it must not contain more than 10 parts per million of total dissolved solids), and may also be free of microbes if treated by distillation or reverse osmosis. Purified water may alternately be labeled according to how it is treated.
Sterile water – water that originates from any source, but has been treated to meet the U.S. Pharmacopeia standards for sterilization. Sterilized water is free from all microbes. Note: Carbonated Note: Carbonated water, soda water, seltzer water, sparkling water, and tonic water are considered soft drinks and are not regulated as bottled water. Common Bottled Water Treatments Distillation – water is boiled, and the steam is condensed to remove salts, metals, minerals, asbestos, particles, and some organic materials
Micron Filtration – water is filtered through screens with microscopic holes. The smaller the filter holes, the more contaminants the filter can remove. Good filters can remove most chemical contaminants and microbes. Filter holes are measured in microns. (The period at the end of this sentence is 500 microns.) When considering filter size, look for an absolute (the largest hole), not nominal (the average hole) rating. An absolute one micron filter is needed to remove Cryptosporidium.
Ozonation – water is disinfected using ozone, which kills most microbes, depending on dosage applied. Reverse Osmosis(RO) – water is forced under pressure to pass through a membrane, leaving contaminants behind. This process removes all microbes, minerals, color, turbidity, organic and inorganic chemicals.
Ultraviolet (UV) light – water is passed through UV light, which kills most microbes, depending on dosage applied.