North Carolina’s environment agency asked Tuesday that its own enforcement cases over Duke Energy coal ash practices at 10 power plants be put on hold.

The motions drew sharp responses from Duke and environmental advocates who have come to cleanup terms on three of the plants.

The Department of Environment and Natural Resources filed the requests before courts in Mecklenburg and Wake counties. They say ash cleanups should be determined by the state Coal Act Management Act, not the courts.

CAMA dictates how Duke’s 32 ash ponds are categorized and closed. The state is to set priority rankings, which will determine the timing of the closures, in December.

“A stay of these proceedings will ensure careful consideration of each of these factors, including the economic impacts of the proposed manner of closure, during the process for approval of closure plans,” DENR’s motions said.

The court cases, if allowed to go forward, would erase the public comment and scientific analysis required under the coal ash law, the department argued. The law allows some ash to remain in drained ponds instead of being removed.

Duke denies that it intended to go around the coal ash law in asking a judge last month to close state cases over three power plants. Duke has agreed to excavate ash from ponds at those plants.

“Duke Energy is fully committed to the CAMA process and to closing ash basins in ways that are safe for people and the environment,” spokeswoman Paige Sheehan said in a statement Tuesday.

The Southern Environmental Law Center, which represents environmental advocates, charged that DENR’s court motions attempt to shield the department and Duke from releasing information the advocates seek.

“DENR has become a bureaucracy that puts its bureaucratic turf issues ahead of its mission to protect North Carolina’s communities and clean water,” senior attorney Frank Holleman said in a statement.

The coal ash law requires that the potential costs to consumers be considered in closing the ponds. Duke’s current cleanup estimate is $3.5 billion and has said it will ask permission to pass costs to customers. DENR cites an earlier estimate of up to $10 billion.