GASTON COUNTY -- The North Carolina Department of Environmental Quality is investigating a newly-discovered leak from a corrugated metal pipe connected to a coal ash basin at the Allen Steam Station on Lake Wylie in Gaston County.

The department’s investigation began after Duke Energy notified regulators of the leak on Wednesday. Sam Perkins, the Catawba Riverkeeper, first alerted Duke employees to the pipe problem.  "What we were most concerned about is that this was a corrugated metal pipe that took us 20 minutes to find, but the Duke personnel didn't know what it was, they didn't have a record of it," said Perkins.

Perkins said the type of pipe and conditions under which it was left largely unmonitored as part of a decommissioned coal ash facility are similar to the pipe at the heart of the Dan River coal ash spill in February 2014.

"There is a corrugated metal pipe, same material as Dan River, going under an ash basin, like at Dan River, with very corrisive conditions created by that ash,"  said Perkins.

Duke Energy said in a statement that groundwater likely seeped into the pipe, and the amount of water leaking was akin to a coffee cup per minute. The company took a sample of the water and found it met state surface water standards.

Duke Energy said this situation doesn't compare to what happened on the Dan River. The DEQ plans to grout the end of the pipe to stop the leak.