The test results released by the state and Duke showed water samples contained arsenic at up to 40 parts per billion. The state limit in rivers and lakes is 50 parts per billion. Readings for lead were recorded at 23 parts per billion, just below the state limit.
The state did note readings for copper were above state levels, but because it is a naturally occurring element in North Carolina waters, the state said further testing would be needed to see if the ash spill was to blame.
The U.S. Environmental Protection Agency has also conducted extensive testing. So far, those results have not been made public.
The numbers released by Duke and state regulators were in sharp contrast to findings by the Waterkeeper Alliance, an environmental group founded by Robert F. Kennedy Jr.
The Alliance said its samples showed arsenic at nearly 350 parts per billion, seven times the level the state says is safe for aquatic life. The group also reported readings of lead at 129 parts per billion, more than five times the state limit.
"If a terrorist group committed in North Carolina — for ideological reasons — a crime that Duke Energy has committed for profit, our nation would consider it an act of war against our country," Kennedy said.
At Duke's headquarters in Charlotte, about 30 protesters marched and carried signs urging Duke to "Clean Up Coal Ash Now." They said the company was negligent in the spill.
"Duke has assured us that these coal ash dumps are safe," said Bill Gupton, chairman of the Central Piedmont Group of the Sierra Club. "But they're not."
Associated Press writer Mitch Weiss reported from Charlotte.
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