A new study has found one liter of bottled water uses as much as 2,000 times more energy compared to the public tap water.

Despite knowing that bottled water is only marginally different than tap water and costs thousand times more, still people are consuming bottled water in large numbers. From 1976 to 2006, the average amount of bottled water sold per person per year in the United States jumped from about 6 liters (1.6 gallons) to 116 liters (30.6 gallons).

A recent government study found the cost of bottled water is 2000 times the cost of the public tap water in New York.

Department of Environmental Protection told New York Times that city tap water costs $5.99 per 100 cubic feet, eight ounces of New York water cost five one-hundredths of one cent, or $0.0005, including the cost of treating the wastewater. That makes the same size eight ounce bottle of Poland Spring check in at 2000 times the cost at one dollar.

The new study conducted by the Pacific Institute for Studies in Development Environment and Security in Oakland, California found bottled water consumes as much as 2,000 times more energy than tap water. The study also found the total bottled water consumption in the U.S. consumes 32 to 54 million barrels of oil in 2007.

Americans purchased more than 33 billion liters of bottled water and worldwide more than 200 billion liters of bottled water was sold.

The appetite for bottled water is growing at a high pace, since 2001, bottled water sales have increased by 70 percent. Consumers buy more bottled water than either milk or beer. The increased consumption of bottled water has increased the consumption of energy. If we add the total amount of plastic waste discarded into the environment, the costs will be even higher.

Peter Gleick, President of the Pacific Institute and his team compared three case studies, water bottled and used in Los Angeles, water bottled in South Pacific and shipped to Los Angeles and water bottled in France and shipped in different ways to Los Angeles.

They found that for local bottling company, the energy-intensive step is in producing the PET plastic bottles and for longer trips transportation consumes more energy.

They advise to drink water locally, which will help save more energy and costs less.

Gleick told Discovery:

"We have very good tap water in this country...It's cheap. It's readily available. And it's much lower in energy use."

The study’s findings are presented in the current journal Environmental Research Letters.

How many more studies need to be done to persuade people from drinking bottled water that costs more, consumes more energy and produces more environmental waste?