“We don’t have any plans to change how we test or remove chromium from the water,” Russell said. “We’re not even close to that threshold.”

But those behind the Environmental Working Group report say that current safety thresholds for chromium levels in drinking water are far too loose and don’t reflect health concerns raised by studies from the last two decades.

The federal standard for total chromium was set in 1991 and was based on concerns regarding skin irritation, according to Andrews. Those guidelines don’t take into account a 2007 study that he says found “a significant increase in stomach and intestinal tumors” in rodents that drank water with elevated levels of chromium-6 over a period of two years.

“(The federal standard) overlooks or disregards 25 years of science that has been telling us about the more serious effects of chromium-6,” said Bill Walker, another Environmental Working Group representative.