Walk down the drinks section at the supermarket.Look in the drink cooler in your local convenience store.A new drink is taking up more and more space on the shelves，and that drink is water.Bottled water sales in the US rose to 1.7 billion gallons in 2010 for plastic bottles alone，compared to total sales of only 700 million gallons in 1990. Whereas bottled water was once associated only with the rich and the privileged (特权阶层)，it is now regularly drunk by people at all income levels despite the fact that the price of bottled water can be between 240 and 10,000 times higher per gallon than tap water.What accounts for this surprising increase in demand?
Traditionally，people have drunk bottled water for health reasons.The practice of “taking the waters” originated with the Romans，who believed that a person developed a healthy mind by building a healthy body.Across Europe，drinking or bathing in mineral water has been associated with the power to cure various diseases.Health spas at Evian in France and Pellegrino in Italy began bottling water so that their consumers could continue their treatments at home.The consumers in the 21st century are also concerned about health.However，in America，where the habit of drinking bottled water is relatively new，the concern is often more related to the purity or sterilization (消毒) of the water than to its mineral contents.Americans are often worried about the effects of the chemical pollution and other contaminants on the water supply.Many Americans view bottled water as a safe alternative to tap water.
Further reasons for drinking bottled water are its usefulness as an aid to digestion，as a complement to a good meal in a restaurant，and for taste.City tap water is often treated with chlorine (氯) to guard against harmful microorganisms.Chlorine，as well as metals from pipes and tanks used to distribute and store tap water，can leave behind an unpleasant taste.
