Milwaukee City Wire

Chemical Safety and Hazard Investigation Board (CSB) member Sylvia Johnson is urging those in the industry to ensure they read the agency’s final report on the 2018 refinery explosion and fire at the Husky Superior Refinery in Superior, Wisconsin.

Reviewing the report could help prevent similar disasters, according to a CSB news release.

"These safety issues seek to address incident causes,” Johnson said in the release. “We call on refineries, trade groups, and regulators to examine our final report and apply the key lessons to help ensure safe operations at facilities throughout the country and to develop and adopt effective emergency response practices."

The explosion injured 36 workers, caused approximately $550 million in damage, and released 39,000 pounds of flammable hydrocarbon vapor; the release stated.

It occurred when the refinery was shutting down its fluid catalytic cracking (FCC) unit to perform planned maintenance, was sparked when two vessels in the FCC unit exploded propelling metal fragments up to 1,200 feet away. The fragments punctured a nearby asphalt storage tank causing the spilling of approximately 17,000 barrels of hot asphalt and several fires.

More than 2,500 Superior residents were forced to evacuate their homes, prompting Duluth, Minnesota, to issue a shelter in place order. Investigators blamed the mishap on Husky officials, according to the report.

The CSB highlighted six safety concerns in the report and issued 16 safety recommendations for Husky Energy, which merged with Cenovus Energy in 2021, the United States Occupational Safety and Health Administration, U.S. Environmental Protection Agency, and the American Petroleum Institute.

It also called on the EPA to develop and implement a protocol for inspecting facilities like the Husky Refinery and developing emergency protocols and training programs to be better prepared for similar events.