Washington ? Walk through the beverage aisle of a grocery store and it is hard to miss the seemingly endless supply of bottled water on the shelves.

Sparkling, fizzy, mineral, distilled, purified — bottled water comes in many forms as well as flavors such as lemon, black cherry, raspberry, kiwi and strawberry.

Manufacturers sold more than $7.7 billion worth of bottled water last year, an increase of 12.3 percent from 2001, according to the Beverage Marketing Corporation.

Last year, the average consumer drank 21 gallons of bottled water, about 11 percent more than in 2001, the marketing group says.

Some environmental groups and consumers are concerned both about bottled water’s price and effect on the world’s water supply.

The Natural Resources Defense Council estimates that bottled water is 240 times to 10,000 times more expensive than tap water. While consumers may pay a few dollars for every thousand gallons of tap water, they can pay almost $2 per gallon of some brands of bottled water.

The organization also says the booming bottled water industry could be draining aquifers and other water resources, contributing to pollution and producing energy inefficiencies.

There’s “an immense waste of energy and plastic and resources if you consider the number of bottles that are made and transported and disposed of,” says Erik Olson, a lawyer for the group.

Researchers are warning that if water use continues to increase at the current rate, the world will be in very short supply in 22 years.

J. Darius Bikoff, president and chief executive of Energy Brands Inc., says the water it markets is a tiny fraction of total water usage.