What you may not remember, however, is the contaminate at the center of this legal battle. The alleged cancer-causing metal in question was hexavalent chromium, or chromium-6. The good news is that the NIH finally labeled chromium-6 as a "probable carcinogen" (it's believed to cause stomach cancer, among other ailments) back in 2008, and that the great state of California (which has led the way in setting environmental standards and regulations since the 1970s) proposed to set a MCL (a limit on the acceptable amount of contaminate present) in its drinking water to 0.06 parts per billion. The bad news is that the EPA has no limit on the allowable amount of Cr-6, nor does it regularly test the nation's water supply for the presence of such a chemical.
So why do I think this is a big deal? Well, an independent environmental organization, the Environmental Working Group, took it upon themselves to test the drinking water of 35 cities around the U.S.; chromium-6 was found in the water supply of 31 of those cities, and in 25 of those cities, the amount was well above California's proposed limit.
In Chicago, the tests revealed Cr-6 amounts of 0.18 parts per billion; three times what California suggests is safe. Uh oh. The water pollution in this city is suspected to have come in part from the south side steel mills and other riverside industries, as the substance was widely used until the mid 1990s. Although the EPA has agreed to review its stance on hexavalent chromium, utility companies and industrial polluters are already fighting back. If the EPA does in fact set limits on the allowable amount of chromium-6 to enter the water supply, it will be very difficult (not to mention expensive!) to clean up, and companies are reluctant to dip into their profit shares to remediate the problem in the interest of public health. We're all drinking the water, though, so if I knew there was a way to lower my family's risk of certain cancers, liver and kidney damage, and leukemia, I'd consider it a small price to pay.