ArcelorMittal Burns Harbor has cleaned up a spill of 10,000 gallons of ammonia liquor that was discharged during a brief power outage Feb. 5.
The Indiana Department of Environmental Management is checking to see if any more work needs to be done.
"Our understanding is the spill abatement has been completed," IDEM Public Information Officer Barry Sneed said. "IDEM staff are scheduled to visit the facility to assess cleanup and make a determination if any additional actions are needed."
The spill took place last Tuesday because of a "high voltage power interruption" that caused massive flaring as the steel mill burned off excess coke oven gas during a disruption to the steelmaking process. A Porter Volunteer Fire Department firefighter suffered heat exhaustion while working to control the flames and had to be taken to a hospital.
"The outage also resulted in the release of water-diluted flushing liquor onto ArcelorMittal property," ArcelorMittal spokeswoman Mary Beth Holdford said. "Regulatory agencies were notified immediately, and the spill was contained and clean up was successfully completed."
The power outage caused a backup in the production line and an overflow of the liquid waste byproduct onto the ground. Sneed confirmed it was contained on site at the former Bethlehem Steel mill on the lakefront.
"There are no offsite exposure threats to public health or the environment," he said.
Crews worked overnight to vacuum up the spill of ammonia, a naturally occurring chemical that does not bioaccumulate or last long.
ArcelorMittal Burns Harbor restored operations within about 12 hours, and Holdford said the interruption did not affect the mill's ability to meet customer demand.