North Carolina regulators said Duke Energy could face fines after 30,000 tons of coal ash spilled into the Dan River, according to Reuters.
Duke was cited with two notices of wastewater and stormwater violations from the state's Department of Environmental and Natural Resources (DENR), after the Feb.2 incident.
The DENR said the utility could face civil fines of up to $25,000 per day.
The coal ash spill occurred after a pipe broke; officials later found a second leak of arsenic-laced discharge from a separate pipe. Duke officials and state regulators said both leaks have been plugged.
On Friday, the DENR said Duke violated water quality laws, rules, and lacked proper water-discharge permitting. In addition, the DENR also said Duke neither applied for, nor was issued, a permit for discharging stormwater from a steam electric power generating facility into state waters, the article said.
U.S. prosecutors have requested inspection records and copies of correspondence between the DENR and Duke Energy.