RALEIGH, N.C. | Thu May 14, 2015 10:35pm BST

Duke Energy Corp pleaded guilty on Thursday to environmental crimes over a North Carolina power plant's coal ash spill into a river and management of coal ash basins in the state, U.S. prosecutors said.

The plea entered in federal court in Greenville, North Carolina, by the country's largest utility owner was expected under a settlement with the U.S. Department of Justice announced in February.

As part of the deal, Duke agreed to pay $102 million in fines and environmental projects, and to reserve more than $3 billion to comply with environmental standards.

“Duke Energy's crimes reflect a breach of the public trust and a lack of stewardship for the natural resources belonging to all of the citizens of North Carolina,” U.S. Attorney Thomas Walker said in a statement.

The company admitted to failures at five of its power plants over several decades that allowed coal ash to enter waterways, including documented problems with the 48-inch pipe that would eventually cause the spill into the Dan River in February 2014.

The stormwater pipe beneath a coal ash pond at Duke's retired power plant in Eden ruptured, releasing up to 27 million gallons of wastewater and as many as 39,000 tons of coal combustion residue into the river that supplies drinking water to two towns in neighboring Virginia.

Duke “failed to take reasonable steps to minimize or prevent discharge of coal ash to the Dan River that would adversely affect the environment," according to a joint statement filed by the company and prosecutors in federal court.

Duke and its subsidiaries pleaded guilty to nine misdemeanor violations of the Clean Water Act.
In a statement on Tuesday, the company pledged to "operate our system as safely as possible."

Duke has separately agreed to close and clean up coal ash sites at 14 coal plants in North Carolina, though their methods have been disputed.

Duke’s environmental critics lauded the settlement, one of the largest levied for clean water violations, but noted other lawsuits continue.

“This confirms that Duke has committed serious and long-standing environmental crimes,” said John Suttles, an attorney with the Southern Environmental Law Center. “But it does not clean up the coal ash that is every day continuing to contaminate our drinking water.”