Both the Government Accountability Office and the Environmental Working Group, a nonprofit research and advocacy organization, recommend in reports released Wednesday that bottled water be labeled with the same level of information municipal water providers must disclose.
The researchers urged Americans to make bottled water "a distant second choice" to filtered tap water because there isn't enough information about bottled water. The working group recommends purifying tap water with a commercial filter, however.
Both reports were released at a congressional subcommittee Wednesday morning.
Jane Houlihan of the Environmental Working Group says consumers drinking a bottle of Dasani water don't even know where it comes from, reports CBS Radio News' Bob Fuss.
"On this label you'll see that the product is pure and it's crisp and it has a fresh taste, but no where on this label will you find the source of that water," Houlihan said.
The GAO told the committee that the safety and consumer protection are "less stringent" for bottled water than they are for tap water, reports CBS News correspondent Kelly Wallace.
Sarah Walton never gives her young son bottled water and stopped drinking it herself before she got pregnant last year.
"I think the biggest danger is just not knowing what's in it," she said.
Dozens of other moms told CBS News via Twitter they agree.
At today's hearing, the Government Accountability Office said bottled water should be regulated as stringently as tap water.
Currently tap water must be tested in certified labs - not the case with bottled water; and tap is checked for maximum levels of DEH, a potentially dangerous chemical - not bottled, Wallace reports.
Bottled water - an industry worth about $16 billion in sales last year - has been suffering lately as colleges, communities and some governments take measures to limit or ban its consumption. As employers, they are motivated by cost savings and environmental concern because the bottles often are not recycled.
Bottled water sales were growing by double-digit percentages for years and were helping buoy the U.S. beverage industry overall. But they were flat last year, according to trade publication Beverage Digest.
Beverage Digest editor John Sicher said some consumers are turning on the tap during the recession simply because it's cheaper. Many restaurants and businesses are no longer buying bottled water - choosing to filter their own instead.
From 1997 to 2007, the amount of bottled water consumed per person in the U.S. more than doubled, from 13.4 gallons to 29.3 gallons, the GAO report said - to an average of 200 bottles for every man woman and child in this country.
The issue before a subcommittee of the Energy and Commerce Committee was less about waste and water quality concerns and more about the mechanics of regulating bottled water.
As a food product, bottled water is regulated by the Food and Drug Administration and required to show nutrition information and ingredients on its labels. Municipal water is under the control of the Environmental Protection Agency.
The two agencies have similar standards for water quality, but the FDA has less authority to enforce them, the GAO said, and the environmental agency requires much more testing.
Subcommittee chairman Rep. Bart Stupak, D-Mich., said the subcommittee was requesting information Wednesday from a dozen bottled water companies on their water sources, treatment methods and two years' results of contaminant testing. It was not immediately clear which companies were being contacted.
"Consumers may not realize that many regulations that apply to municipalities responsible for tap water do not apply to companies that produce bottled water," he said in statements opening the hearing.
The GAO noted the FDA has yet to set standards for DEHP, one of several chemicals known as phthalates that are found in many household products, while the EPA limits the presence of phthalates in tap water.
In a survey of officials in all 50 states and the District of Columbia, the GAO found they think consumers are misinformed about bottled water.
"Many replied that consumers often believe that bottled water is safer or healthier than tap water," according to the GAO report.
The Washington, D.C.-based Environmental Working Group said in its report that consumers do not get enough information to determine which water is best for them.
Both groups said some bottled water brands include the same information required of tap water providers on either labels or company Web sites.
The GAO called for more research but said the FDA should start by requiring that bottled water labels tell consumers where to find out more.
Community water systems must distribute annual reports about their water's source, contaminants and possible health concerns.
Consumers should know where all their water comes from, how it is treated and what is found in it, said Richard Wiles, senior vice president for policy and communications for the Environmental Working Group.
"If the municipal tap water systems can tell their customers this information, you would think that bottled water companies that charge 1,000 times more for this water could also let consumers know the same thing," he told The Associated Press.
The bottled water industry's trade group, the International Bottled Water Association, planned to testify Wednesday that the product, - subject to the same regulation as other soft drinks, teas, juices and other beverages - is safe. Additional standards apply for bottled water products labeled as "purified water" or "spring water," among other labels, because they must prove a connection to those sources, according to planned testimony from Joseph Doss, president and chief executive of the International Bottled Water Association.
Doss said consumers can learn about bottled water by contacting the company, reading its Web site and visiting sites run by state governments.
State safeguards for bottled water often exceed the federal, though they are less stringent than for tap water, the GAO wrote.
The trade group declined to comment on the reports before they are released.