that the state was misleading homeowners regarding how safe their drinking water was by citing safe drinking water guidelines set by the federal government.
The consequence of that deposition was severe blowback from top administration officials. McCrory's chief of staff, Thomas Stith, accused Rudo of lying under oath. However, Rudo has maintained the veracity of his testimony both in a public statement and in a subsequent deposition. As a result of the controversy, North Carolina's chief epidemiologist, Dr. Megan Davies, resigned in protest against the "false narrative" that the administration was circulating about coal ash.
Currently there is no federal drinking water standard for chromium-6, though there is one for total chromium of 100 parts per billion. It assumes that most of the chemical will be of the nontoxic chromium-3 variety.
Out of all 50 states, California is the only one with a statewide chromium-6 standard, which is set at 10 parts per billion.
It is this dearth of guidance and jumble of regulations, said Vengosh, that makes it difficult for those who rely on wells for their drinking water to know how to react.
"If you are a homeowner and you have these values for chromium, you really don't know how it relates to any health standard," he said.
Vengosh cautioned that he was not a health expert, but said that California's hexavalent chromium standard appears to be a reasonable point at which concern should begin. The study discovered wells—both close to and far from coal ash pits—that exceeded the standard.
This fact, according to Vengosh, will probably pressure additional states to set their own chromium-6 standards, and it also indicates the necessity for the federal government to set guidelines rather than leaving the problem to the states.
"We need urgently a standard for hexavalent chromium," Vengosh said. "We need to know what thousands of well owners should be doing. ... This is an emergency even worse than coal ash."