PORTAGE - Pittsburgh-based U.S. Steel Corp. (NYSE: X) has shut down parts of its Midwest Plant in Portage. Our partners at The Times of Northwest Indiana report the steelmaker made the decision Wednesday after a discharge of hexavalent chromium into the Burns Waterway exceeded the allowed limit.

In a statement to the publication, U.S. Steel spokesperson Amanda Malkowski said the company shut down the facility's chrome treatment plant, tin line and chrome lines after lab results showed it was in violation of discharge permits.

"At approximately 4:50 p.m. on October 30, 2019, we were notified of an exceedance of our National Pollutant Discharge Elimination System permit limit for hexavalent chromium," Malkowski told The Times. "Elevated results were detected at an internal outfall at our Midwest Plant in Portage, Indiana during routine, daily sampling. We were notified that an initial sample result was over the limit for hexavalent chromium, which is 0.51 lbs. Our subsequent sample, taken later that day, was under the limit. Therefore, our average flow for Oct. 30, was slightly over the limit of 0.51 lbs. per day."

According to the Occupational Health and Safety Administration's website, hexavalent chromium is used in industrial processes and is known to cause cancer, among other adverse health effects.

Malkowski says the identified portions of the plant will remain shut down as the company continues its investigation. 

"The Indiana Department of Environmental Management has been notified, along with other local stakeholders," said Malkowski. "An investigation into this matter is ongoing. We are committed to working with local officials and to communicating with the public on this matter. Safety and environmental performance remain our top priorities."

The Times says U.S. Steel had to pay a $1.2 million settlement after spilling more than 900 pounds of hexavalent chromium from the Midwest Plant into the Burns Waterway and Lake Michigan in 2017.