MPCA investigating process water pipe rupture at Silver Bay taconite plant

Environmental regulators are investigating after a pipe ruptured at the Cleveland-Cliffs' North Shore Mining processing plant in Silver Bay on Wednesday.

A Minnesota Duty Officer report of the incident, provided by the Minnesota Pollution Control Agency, states the rupture happened at 2:41 p.m. and the pipe was shut down at 2:52 p.m.

"The water is recycled water with some fluoride and miscellaneous substances but nothing of particular concern or note," the report reads.

The leak released approximately 21,000 gallons of water, according to Patricia Persico, a spokesperson for Ohio-based Cleveland-Cliffs.

"A process water pipeline undergoing routine maintenance developed a leak upon being returned to service and pipeline was immediately shut down," Persico stated in an email. "We are working with MPCA to determine if any impacts to the environment occurred."

Plant operations were not impacted by the incident, Persico added.

In a statement, MPCA spokesperson Michael Rafferty said the state is "currently evaluating the situation to determine impacts."

"This is an ongoing investigation," he wrote Friday.

The spill was first reported Thursday by the Duluth News Tribune .