OSHA: Explosion, fire at Superior refinery could have been prevented

October 3, 2018

The oil refinery explosion and fire that rocked Superior, Wis., in April could have been prevented if the plant’s equipment had been properly maintained, a federal investigation has found.

The Occupational Safety and Health Administration levied an $83,150 fine for 13 violations including outdated safety procedures, failures to address certain hazards, and failed inspections and testing, among other problems.

“Ensuring the mechanical integrity of critical equipment used during the refinery shutdown operation could have prevented this incident,” OSHA spokesman Mark Hysell said in a statement.

The findings, delivered to Superior Refining Company on Tuesday by OSHA’s Eau Claire, Wis., office, come two months after a finding from the U.S. Chemical Safety and Hazardous Investigation Board that said the massive explosion at the Husky Energy refinery could have been caused by a worn valve that allowed air to leak and mix with combustible hydrocarbons.

The April 26 blast sent shrapnel into a tank of asphalt, which eventually caught fire and burned for hours, sending a plume of black smoke and ash far across northwestern Wisconsin. City officials feared that a tank of highly toxic hydrogen fluoride at the plant was also vulnerable, and ordered a near citywide evacuation as a precaution.

An Environmental Protection Agency worst-case scenario for the plant says a massive leak of the hydrogen fluoride tank would put 180,000 people at risk, or most of the Twin Ports population. The mayors of Superior and Duluth have each asked the company to use alternative chemicals and remove the hydrogen fluoride from the site permanently.

Eleven workers were hurt in the blast, and 25 other people also sought medical attention. The workers filed a lawsuit in August, alleging they had to run for their lives to escape. A class-action lawsuit filed in August by some residents of Superior, Wis., seeks payment for the costs they faced due to fleeing the city.

Husky Energy, Inc., the owners of the Superior plant, say they don’t expect to resume normal operations until 2020.

Company officials did not immediately respond to a request for comment on the OSHA findings.

Matt McKinney • 612-217-1747

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