Study Finds Probable Carcinogen in Honolulu Tap Water
A spokesman for the Honolulu Board of Water Supply said news of a report that lists Honolulu as second among U.S. cities with high levels of a carcinogen in its tap water had the agency “scrambling” this morning. Kurt Tsue said the Board of Water Supply is planning to conduct its own study to verify the findings of an report. The study found Honolulu has the second highest level of hexavalent chromium, a probable carcinogen made famous by the film “Erin Brockovich,” in its tap water.
“We do not test specifically for hexavalent chromium, however we do test for overall chromium,” Tsue said. “Up until now, that has been the standard for testing for that particular contaminate. The EWG, this Environmental Working Group, is calling on the EPA to set new lower standards to check for this particular contaminate.”
The EPA is considering setting a limit on the presence of hexavalent chromium in tap water because the National Institutes of Health found it to be a “possible carcinogen” in 2008. Officials at the EPA say they’ll decide sometime in 2011.
After the report was released Monday morning, Tsue said officials at the Board of Water Supply began arranging to test local water samples for the toxic compound. But it’s unclear when that can happen or how much it will cost.
“Just to be sure, we are going to do our own analysis,” Tsue said. “We don’t have the equipment to test for that extremely low level of chromium, so we are going to look for a contractor and a lab.”
Chromium is released to the environment mostly from man-made sources, though researchers have found hexavalent chromium naturally occurring in ground water and surface waters in California, Pakistan, Italy, Zimbabwe and elsewhere. In 1992, the EPA set a regulation for chromium — all chromium, not just hexavalent chromium — at 0.1 mg/L, or 100 parts per billion.
“The standard for total chromium across the nation is 100 parts per billion,” Tsue said. “No area on Oahu do we exceed that 100 parts per billion.”
The EPA has studied hexavalent chromium for more than a decade. While the agency other forms of chromium found in drinking water as “nutritionally essential,” it finds the “more toxic” hexavalent chromium poses “potential health risks to people.”
The Environmental Working Group found 2 parts per billion of hexavalent chromium in Honolulu. The highest incidence it found was in Norman, Okla., where the group recorded 12.9 parts per billion of hexavalent chromium. In Boston, researchers found 0.3 parts per billion of the toxic compound. In Hinkley, Calif., the town made infamous by Erin Brokovich, some concentrations of groundwater had as high as 580 parts per billion of hexavalent chromium. California is considering limiting the chemical to .06 parts per billion.
In September, the EPA a new, interagency toxicological review of hexavalent chromium.
“EPA regularly revaluates (sic) drinking water standards and, having new science, we had already launched a rigorous and comprehensive review of the effects of chromium-six on human health,” officials from the regional EPA office wrote in a statement. “EPA will carefully review the conclusions (of the new toxicological review) and consider other relevant information, including the Environmental Working Group’s study, to determine if a new standard needs to be set.”
Tsue said the local sampling — which reportedly came from a single residence — could be problematic.
“We kind of question it in a sense,” Tsue said. “If it comes from a residence, not the source, we don’t know where the hexavalent chromium comes in.”
Tsue points out that antiquated pipes or other infrastructure could have carcinogenic properties, and it is homeowners’ responsibility to upgrade accordingly. Representatives at the Environmental Working Group did not return phone calls before publication.
Interestingly, the research and advocacy group that issued the report Monday praised Honolulu for the quality of its drinking water in a . In that report, Honolulu ranked sixth-best based on the total number of chemicals detected since 2004, the percentage of chemicals found and other criteria.
“We test every year, and we share those results with our customers.” Tsue said. “We’ve never had a violation. We do everything we can to ensure that we have safe drinking water. We are committed to protecting public health. We are paying close attention to this study, and no matter what comes out of this, we will continue to meet safe drinking water standards.”
