A debate over water is boiling over in the United States and elsewhere amid growing environmental concerns about bottled water and questions about the safety of tap water.

The US Conference of Mayors last week passed a resolution calling for a phasing out of bottled water by municipalities and the promotion of the importance of public water supplies.

While largely symbolic, the vote highlighted a growing movement opposing the regular use of bottled water because of the plastic waste generated and the energy costs of transporting drinking supplies.

Ms Janet Larsen, director of research at the Earth Policy Institute, cites a "backlash against bottled water as more people are realising what they get out of the bottles is not any better than what they get out of the faucet".

The Pacific Institute, a California think-tank on sustainability issues, contends that producing bottles for US water consumption required the equivalent of more than 17 million barrels of oil in 2006.

The group says bottling water for Americans produces more than 2.5 million tonnes of carbon dioxide and consumes three litres of water for each litre of bottled water produced.

Americans drank about 33 billion litres of packaged water last year, or 15 per cent of their total liquid intake, according to the Beverage Marketing Corp.

Per capita bottled US water consumption is up to 109 litres per year, from 75.7 litres in 2002.

The debate in the US mirrors that taking place worldwide in other big consumer countries such as France, Britain, Italy, Canada and Australia.

Natural Resources Defence Council, a New York-based environmental advocacy group, says "about one-fourth of bottled water is actually bottled tap water" while government rules "allow bottlers to call their product 'spring water' even though it may be brought to the surface using a pumped well, and it may be treated with chemicals."

The industry says it is being used as a scapegoat.

Mr Kevin Keane of the American Beverage Association said the mayors' resolution was "just cynical politics".

He said the bottled water industry is needed for communities hit by floods or other natural disasters and compromised municipal water systems.

The International Bottled Water Association, an industry group based near Washington, says the industry uses less than 1 per cent of groundwater supplies and produces only a tiny fraction of greenhouse gases.

Mr Joe Doss, president and chief executive of the association, adds that water bottles represent a tiny fraction of plastic waste even if not recycled, and that any effort to improve recycling should cover all industries and not just the bottled water industry. -AFP