The highest levels were in Norman, Oklahoma, Honolulu, Hawaii, and Riverside, Calif. In all, water samples from 25 cities contained the toxic metal at concentrations above the safe maximum recently proposed by California regulators.

The cities tested are:
Norman, Okla. – 12.9 ppb
Honolulu, Hi. – 2.00 ppb
Riverside, Calif. – 1.69 ppb
Madison, Wis. – 1.58 ppb
San Jose, Calif. – 1.34 ppb
Tallahassee, Fla. – 1.25 ppb
Omaha, Neb. – 1.07 ppb
Albuquerque, N.M. – 1.04 ppb
Pittsburgh, Pa. – 0.88 ppb
Bend, Ore. – 0.78 ppb
Salt Lake City, Utah – 0.30 ppb
Ann Arbor, Mich. – 0.21 ppb
Atlanta, Ga. – 0.20 ppb
Los Angeles, Calif. – 0.20 ppb
Bethesda, Md. – 0.19 ppb
Phoenix, Ariz. – 0.19 ppb
Washington, D.C – 0.19 ppb
Chicago, Ill. – 0.18 ppb
Milwaukee, Wis. – 0.18 ppb
Villanova, Pa. – 0.18 ppb
Sacramento, Calif. – 0.16 ppb
Louisville, Ky. – 0.14 ppb
Syracuse, N.Y. – 0.12 ppb
New Haven, Conn. – 0.08 ppb
Buffalo, N.Y. – 0.07 ppb
Las Vegas, Nev. – 0.06 ppb
New York, N.Y. – 0.06 ppb
Scottsdale, Ariz. – 0.05 ppb
Miami, Fla. – 0.04 ppb
Boston, Mass. – 0.03 ppb
Cincinnati, Ohio – 0.03 ppb

According to the EPA, hexavalent chromium is “likely to be carcinogenic to humans.” Yet, EWG reports, “Despite mounting evidence of its toxic effects, the EPA has not set a legal limit for hexavalent chromium in tap water nationally and does not require water utilities to test for it.”

The National Toxicology Program has said that chromium-6 (hexavalent chromium) in drinking water shows “clear evidence of carcinogenic activity.”

The EWG states that the total number of Americans drinking tap water contaminated with this compound is likely far higher than is indicated by EWG’s tests. At least 74 million people in nearly 7,000 communities drink tap water polluted with “total chromium,” which includes hexavalent and other forms of the metal, according to EWG’s 2009 analysis of water utility tests from 48,000 communities in 42 states (EWG 2009).

At least 74 million people in nearly 7,000 communities drink tap water polluted with “total chromium,” which includes hexavalent and other forms of the metal.

“I was expecting to find hexavalent chromium in some of the cities we checked, but I didn’t expect it to be so widespread,” said Rebecca Sutton, a senior scientist with the Environmental Working Group and the lead author of the study.

Sutton said there is a well-documented corollary between exposure to chromium-6 and a greater risk of stomach cancer in humans. Additionally, there is ample animal evidence showing a broad risk of gastrointestinal tumors in rats and mice exposed to the toxin, she said.
Drinking bottled water in place of tap water does not guarantee you’ll be protected.

“Bottled water is not necessarily any safer than tap water,” said Sutton. “We just don’t have any guarantee that hexavalent chromium isn’t in that water.”

So how can you protect yourself? Sutton says your best bet is buying an reverse osmosis water filter certified to remove this contaminant.

So how can you protect yourself? Sutton says your best bet is buying an reverse osmosis water filter certified to remove this contaminant.

“Getting the water filter is a great way to protect yourself and your family,” says Sutton. “It’s a step you can take yourself; you don’t have to wait for government action.”

Samples from the test provided a “one-time snapshot” of water systems that serve 26 million people, the Environmental Working Group said. But the organization said the results show that more federal regulation of the cancer-causing chemical is needed.

Brendan Gilfillan, an EPA spokesman, said that the agency was aware of the new study by the Environmental Working Group and that the findings will be considered as the agency reviews total chromium in drinking water, work that is expected to be completed next year.

Ken Cook, president of the Environmental Working Group, said that water utilities across the country are resistant to additional regulation.

“It’s not their fault. They didn’t cause the contamination. But if a limit is set, it’s going to be extraordinarily expensive for them to clean this up,” Cook said. “The problem in all of this is that we lose sight of the water drinkers, of the people at the end of the tap. There is tremendous push-back from polluters and from water utilities. The real focus has to be on public health.”

The report is available at www.ewg.org