By Rob Waters

Oct. 15 (Bloomberg) -- Bottled water sold in markets and convenience stores may be no more free of pollutants than the water that pours from the kitchen tap at a fraction of the cost, said an environmental group that tested samples.

Ten top-selling brands of bottled water contained a total of 38 pollutants including fertilizer, industrial chemicals, bacteria and the residue of drugs such as Tylenol, according to a report by the Environmental Working Group based in Washington, D.C. The bottled water showed an average of eight pollutants in each sample.

Americans drank more than twice as much bottled water in 2007 as they did in 1997, guzzling 8.8 billion gallons at a cost of $10.3 billion in 2007, according to the Beverage Marketing Corp., a research and consulting firm based in New York. Although commercials often show pristine mountain springs, the reality is that bottled water often comes from city water supplies, said Renee Sharp, an Environmental Working Group senior scientist.

``If you're going to pay 1,500 times more for bottled water than for tap you'd expect that you'd be getting a cleaner, better product,'' said Sharp. ``And that's not necessarily true.''

Public water utilities are required to inform customers about contaminants that may be present in tap water and, in most states, to tell customers where the water comes from and how it's purified. Companies selling bottled water have few similar rules, Sharp said.

California, which has stricter standards than most states, requires companies to disclose whether bottled water comes from municipal water systems and also to warn consumers about contaminants that may pose health risks.

No Assurances

``But even in California, consumers still can't be assured they're getting a better product'' than they could get from their kitchen sink, Sharp said.

Sharp and her colleagues started their research by buying samples of 10 different brands and sending them to an independent laboratory for testing. They noticed that bottles from Wal-Mart's and Giant Food Inc., a supermarket chain owned by Koninklijke Ahold NV of Amsterdam, seemed to bear the chemical signature of standard municipal water treatment, Sharp said.

In three samples of Sam's Choice purified drinking water sold at Wal-Mart stores near San Francisco, levels of a group of chemicals known as trihalomethanes exceeded state standards, the report said. These are byproducts of chlorine and other chemicals used to kill microbes and can cause cancer at high doses.

Quality is `Top Priority'

Tests conducted by Wal-Mart and its suppliers don't show ``any reportable amounts of chlorine or chlorine by-products,'' Shannon Frederick, a Wal-Mart spokeswoman, said yesterday in an e-mail.

``The suppliers of Sam's Choice water regularly test to verify compliance and quality,'' she said. ``Product quality is a top priority at Wal-Mart, and we stand behind the quality of our bottled water.''

Giant Food spokesman Jamie Miller said in an e-mail today the water marketed by the company is produced with ``numerous safety and quality assurance controls, including a filtration process that assures that the quality of the product meets all regulatory standards for safe drinking water in the areas where we operate.''

While Sharp and her colleagues tested eight bottled water brands in addition to those of Wal-Mart and Giant, the report didn't name the others.

The largest producer of bottled water in the U.S., Nestle Waters North America, a unit of Switzerland-based Nestle SA, said today in an e-mailed statement that the environmental group's report was ``false and misleading'' and seeks to ``undermine the integrity of bottled water.''

Multistep Filtration

Water used in Nestle's brands, which include Poland Spring and San Pellegrino, are tested regularly by independent labs and undergo ``multistep filtration,'' said Heidi Paul, the unit's vice president, in the statement.

``Contrary to the EWG's attempt to equate tap water quality with bottled water, our water is held to a higher standard,'' Paul said.

The Environmental Working Group notified Wal-Mart yesterday that it intended to sue the company for violating the terms of California's Proposition 65, a measure passed by voters in 1986. The regulation requires businesses to notify consumers if products they sell contain significant amounts of chemicals known to cause harm.

Wal-Mart's Frederick said she had no comment on the possible lawsuit.

The increased consumption of water sold in disposable plastic bottles also creates serious environmental problems, Sharp said.

`Enormous Environmental Impacts'

``The environmental impacts of bottled water production are enormous in terms of the amount of energy that goes into producing the bottles and shipping them around the country,'' she said. The bottles also clog landfill sites and increasingly pollute oceans, where they endanger marine animals, she said.

While Giant Food's Acadia brand had similar levels of trihalomethanes, the environmental group doesn't plan to sue the chain under the California statute because it doesn't have stores in the state, Sharp said.

The environmental group wants to see stricter, nationwide standards requiring full disclosure of the contaminants in bottled water and urges consumers to switch from bottled water to tap water. People who are concerned about tap water quality can purchase home filtration systems for a small portion of the cost they pay for bottled water, Sharp said.

To contact the reporter on this story: Rob Waters in San Francisco at rwaters5@bloomberg.net.