Image: Mitwa AV via flickr
Hexavalent chromium, the cancer-causing chemical made famous by the film Erin Brockovich, has been detected in the tap water of 31 of the 35 U.S. cities tested by Environmental Working Group-commissioned studies. That's 89 percent of cities sampled. According to the EPA, hexavalent chromium [PDF] 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."
According to EWG the 31 cities studied collectively serve more than 26 million people. Water in 25 of those cities was found with levels above the safe maximum of .06 parts per billion proposed by California regulators last year. (California is the only state that requires hexavalent chromium testing.) The highest levels were found in Norman, Oklahoma; Honolulu, Hawaii; and Riverside, California.
Check out the map produced by EWG showing more of the test results:
EWG puts the map, and the test findings, into context:
EWG's tests provide a one-time snapshot of chromium-6 levels in 35 cities. But chromium pollution is a continuous, ongoing problem, as shown by the annual water quality reports that utilities must produce under federal law. Over the years, nearly all of the 35 cities tested by EWG regularly report finding chromium (in the form of total chromium) in their water despite using far less sensitive testing methods than those used by EWG.
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).
And then explains at least part of how it came to be this way:
Industry has sought for more than six years to delay state-mandated regulation of hexavalent chromium in tap water in California. Aerospace giant Honeywell International Inc. and others have stalled the adoption of the advisory public health goal by pressing for additional external scientific peer review. California's Department of Public Health can neither set nor enforce a mandatory tap water standard for hexavalent chromium until the goal is finalized.
As for steps forward, EWG is advocating for the EPA to "move expeditiously to establish a legal limit for chromium-6 and require public water suppliers to test for it."
This is by no means a sign to start drinking bottled water instead of tap—there are so many problems with that as a solution, including that it's not cleaner, that it's not worth a second thought. It just means the EPA should be doing its job of protecting the environment and public health. And perhaps filtering your water at home.
More on hexavalent chromium and tap water
EPA Goes Easy on Pollution from Chrome Plating Facilities; Public Health Suffers
Focus on Focus Earth: Erin Brockovitch Still Going Strong--Because the Fight Is Not Over Yet
Which is Healthier: Tap Water or Bottled Water?