It has become a fixture of everyday life - at business meetings, in school lunchboxes, on soccer fields. Bottled water is everywhere.

But it's time to re-evaluate the bottled water boom.

One group that's rightly doing so is the Santa Clara Valley Water District. The agency is embarking on a campaign to promote tap water over bottled water ("Tap is Back"). Its board will vote today on banning the use of district funds for buying single-serving bottled water and stopping the sale of the product in its cafeteria.

These would be largely symbolic but sensible steps. As steward and supplier of water to 1.7 million Silicon Valley residents, the district should push its own product - tap water - while highlighting the environmental problems, financial waste and health misconceptions surrounding bottled water.

More businesses and residents should follow the water district's lead. They should adopt habits like filtering tap water or using bottles that are refillable - steps that often provide good-tasting water in a convenient form while going easy on the environment and finances.

The environmental case against bottled water is mounting.

Americans bought 8.24 billion gallons of bottled water last year, most of it sold in plastic bottles made with fossil fuels. The Pacific Institute estimates that it took more than 17 million barrels of oil to make the plastic bottles, creating more than 2.5 million tons of climate-changing carbon dioxide. It took three liters of water to produce a liter of bottled water, the group estimates.

And that's without the energy needed to transport all those heavy bottles in trucks, trains and ships, sometimes from as far away as Italy or Fiji. Plus, an estimated 86 percent of plastic water bottles ends up in the garbage.

What's more, there are plenty of misconceptions about how clean and safe bottled water is, despite ads and bottle labels evoking pristine glaciers and mountain springs. About one-fourth of bottled water is actually packaged tap water.

The Natural Resources Defense Council tested more than 1,000 bottles of 103 brands and found that one-third contained some level of contamination.

Little wonder that a bottled water backlash has emerged as a hip new ethos among the environmentally conscious. San Francisco Mayor Gavin Newsom in June banned city departments from purchasing bottled water. Chez Panisse, the trend-setting Berkeley restaurant, and other Bay Area eateries recently have stopped serving it, preferring instead to filter or carbonate tap water.

American consumers, who spent $15 billion on bottled water last year, are always free to pay a premium for something that comes for free out of the faucet. But before they do, they should think twice about the impacts of their choice.