While the contents themselves are not especially harmful, the process of producing bottled water does not do the environment any favors. Many health-conscious consumers strongly believe that it is preferable to ordinary tap water, and the water industry's profits run in the billions of US dollars (USD) annually. Even if the bottling and shipping aspects of the industry have a negative impact on the environment, the end result is still viewed as a healthier alternative than tap water processed through municipal treatment plants.
One of the main problems with bottled water production is the reliance on fossil fuels. Raw plastic must be heated before it can be injected into bottle-shaped blow molds, and this heat source is often electricity or natural gas, both of which are produced by fossil fuels. The finished bottles must then be shipped out by trucks or trains, which also burn natural fossil fuels. Add to this the use of additional packaging materials, such as plastic wrap and cardboard. Merely producing the bottles has a negative impact on the environment.
There is also a question about the viability of plastic bottle recycling programs. Although the plastic used in most bottling facilities is considered recyclable, the majority of used containers never see the inside of a recycling center. They are either sent to landfills or are left behind as trash. These plastic bottles do not degrade very quickly, and many generate harmful gases as they disintegrate. As long as recycling efforts remain voluntary, used water bottles will continue to generate these gases and take up valuable space in landfills.
Some experts question the need for bottled water in the first place. Several studies have shown that many of these waters are not produced from the natural or protected sources touted by their manufacturers. Some is little more than purified tap water derived from the same source as municipal drinking water. So-called "spring water" or "Artesian well water" can also contain natural contaminants as the water percolates through the ground before bottling. Side-by-side taste tests between bottled and treated municipal tap water have often revealed very few discernible difference in taste or quality.
Because bottled water is considered to be a "food," regulation and testing in the US falls to the Food and Drug Administration (FDA). The FDA currently requires manufacturers to test their products for harmful contaminants once a week. Municipal tap water is under the jurisdiction of the US Environmental Protection Agency (EPA). The EPA's testing requirements are much more stringent for tap water, requiring water treatment plants to test for contaminants several times a day. In terms of potential harm to people and animals, unchecked bottled water could prove to be much more hazardous than municipal tap water.
Some water treatment experts recommend not refilling plastic water bottles with fresh water from the tap since the plastic might leach toxic chemicals into the water as they degrade, which only becomes more problematic as the bottles become older. Fresh drinking water should be kept in glass or more permanent plastic containers, not in disposable plastic bottles.
While bottled water certainly has its appeal as a portable source of rehydration, it does have some negative impact on the environment. Some experts suggest using a home filtration system to improve the taste and quality of standard tap water instead of buying additional water for drinking purposes. Filters can remove almost all of the most dangerous contaminants and foreign agents found in water, and the purified tap water can be stored in more permanent containers with far less environmental impact than disposable plastic bottles.