California is the only state that has a legal limit put in place for the carcinogenic metal, and it is not regulated on the federal level.
The EPA's testing shows 1,370 U.S. counties have levels of chromium-6 higher than California's public health goal of 0.02 parts per billion. According to EWG, California's current legal limit of 10 parts per billion represents a cancer risk of 500 people per million, for those who drink water with chromium-6 everyday for 70 years. EWG estimates that if the chromium-6 levels are not reduced, this could result in 12,000 excess cases of cancer by the end of the century.
The states with the highest levels of chromium-6 found in their water systems during the study are Arizona, California and Oklahoma. The city of Phoenix had the highest levels at 7.853 parts per billion -- 400 times the California health goal.
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One of the reasons the battle has continued between public health officials, water utilities and state governments is that the cost of clean-up would be staggering. The California Department of Public Health estimates that cleaning the state's water supply to a point of 10 parts per billion would cost about $20 million a year, so getting it down to the recommended level of 0.02 ppb would be even more cost.
So what does the original clean water crusader have to say about all of this? "The water system in this country is overwhelmed and we aren't putting enough resources towards this essential resource," Erin Brockovich told the Guardian. "We simply can't continue to survive with toxic drinking water."
"Superman's not coming," she also told the Guardian. "Be informed, ask questions, band together with your community and fight at the local level. And make sure you take your local elections as seriously as the national ones. The issues that most impact the average person are made at the local level."