“Interviews of Superior Refining Company employees and managers confirmed that inspections and (preventive maintenance work) had not been done,” the team reported. “Further, there was no indication that the spent slide valve was evaluated on either occasion for continued fitness-for-service as a result of the damage and the repairs.”

Ken Rikkola, the refinery’s maintenance manager, told OSHA that welding brought the valve back to new condition. He said weld overlays on the valve were inspected and tested, voicing concerns that a newer valve may not be as reliable. WPR reached out to Rikkola, who didn’t return a request for comment.

Gary Johnston, the refinery’s chief inspector, told OSHA he didn’t “get heavily involved” with the slide valves. Johnston declined WPR’s request for comment, citing ongoing litigation.

In a redacted Nov. 8, 2018 email, a member of the OSHA Health Response Team informed the agency’s assistant area director Ruth “Mitzy” Wright that the repair to the spent catalyst slide valve “was unsatisfactory with poor weld overlays.”

“We hope that Superior takes a hard look at any weld overlay repairs on any other slide valves including the ones in storage,” the email states.

WPR reached out to Houston Services, which did not return a request for comment.

The spent catalyst slide valve was not the only piece of equipment that had issues, according to OSHA. Two vessels that exploded — the primary and sponge absorbers — had shells made of carbon-silicon steels that were installed in 1961. The standards for those metals were withdrawn by the late 1960s. The primary absorber was constructed of steel where known failures of the metal occurred due to brittle fracture or sudden cracking under stress.

Even so, OSHA found no signs the refinery assessed whether that vessel was susceptible to brittle fracture, and testing indicated both of the failed absorbers had metal embrittlement.

In a statement, Cenovus said the refinery is taking steps consistent with OSHA’s recommendations to verify the condition and operability of equipment and control systems.

“The facility is being rebuilt with state-of-the-art equipment, incorporating advances in technology and efficiencies made across the refining industry,” the company said.

Cenovus said that includes new crude and fluid catalytic cracking units that have new state-of-the-art slide valves with advanced instrumentation that will allow operations and engineering staff to monitor their performance. The company said it has resolved all of OSHA’s recommended abatement actions.

The company added that process hazard analyses have been completed for new and unaffected areas of the refinery. OSHA’s inspection team found none of those reviews addressed erosion of the slide valve or the potential for air to enter the system during startups or shutdowns prior to the explosion.

OSHA said in a statement that the agency discussed concerns with the refinery during the planning phase of rebuilding the facility, adding it reserves the right to conduct follow-up inspections.

Former OSHA official says issues revealed are common at refineries nationwide

The problems uncovered at the Superior facility are not uncommon at refineries nationwide, according to a former top OSHA official. Many refineries, including the Superior refinery, were built around 60 or 70 years ago.

Jordan Barab, who served eight years as deputy assistant secretary for OSHA under former President Barack Obama, said he often saw written procedures and training that didn’t reflect actual changes that had been made to equipment at refineries. Because refinery disasters don’t happen often, Barab said they’re often characterized as “low frequency but high impact” events.

From the employers’ perspective, why invest money in something that probably isn’t going to happen?“From the employers’ perspective, why invest money in something that probably isn’t going to happen?” said Barab. “Especially if you know that money can be better spent — or better from their perspective — better spent increasing their profits. Obviously, rewriting procedures and retraining workers and all that kind of stuff is not something that directly leads to profit.”

The refinery had rewritten its operating procedure for shutting down the fluid catalytic cracking unit a day before the explosion, but OSHA’s inspection team found operators in the unit’s control room were following the new procedure without adequate training. Most operators received the revised instructions on the morning of the explosion.

Employees indicated the new procedure was confusing with new and deleted steps. The agency found the refinery didn’t provide clear instructions to address consequences of deviating from the instructions and how to correct situations like the reverse flow of air that investigators believe caused the explosion.

Cenovus said “virtually all” refinery operating procedures have been rewritten since the explosion. The company also said it’s now using an electronic management of change system, a process that seeks to ensure environmental, health and safety risks are evaluated prior to making significant changes.

“We have developed new training materials which combine classroom and field training, along with directed training by subject-matter experts, and training simulators which will match control room equipment, allowing tailored training across a range of operating conditions,” the company said.

Employers must document how they’ve addressed violations, but Barab noted OSHA doesn’t have the resources to inspect every workplace after issuing citations. Under the Trump administration, the number of OSHA inspectors fell to levels that would take the agency more than 165 years to investigate every workplace just once, according to the National Employment Law Project.

Barab said robust involvement from workers is important to improve safety. He noted workers who belong to a union tend to have better knowledge of safety standards than their non-unionized peers and gain more workplace protections through actions like filing complaints.

“That presumes, of course, that the workers in the plant have been trained about the process safety management standard and understand what the requirements are and understand what their rights are,” said Barab.

Despite OSHA’s investigation, which included interviews with more than a dozen refinery workers, contractors and union representatives, few have spoken publicly about the explosion and its aftermath for them.

Eric Mathews, a boilermaker for Wales, Wisconsin-based contractor CTS, Inc., who was working at the refinery on the day of the explosion, told the Duluth News Tribune that day that he heard “a big sonic boom” while he was on break about 200 yards away.

“I was running and then the debris started falling out of the air … I stopped under a pipe rack then waited for the debris to stop falling,” Mathews told the Duluth newspaper.

He said it was lucky that most contractors were in blast-proof buildings when the explosion happened.

WPR reached out to nine contract companies that were at the refinery on the day of the incident, according to OSHA records. Most didn’t respond to requests for comment, while others declined to speak, referring questions to local union representatives. WPR reached out to four local union representatives who either didn’t respond or declined requests for comment with one labor official citing ongoing litigation.

In an April 27 conference call, Cenovus CEO Alex Pourbaix said the cost of rebuilding the refinery has tripled from an initial projected cost of $400 million to $1.2 billion due to COVID-19 supply chain issues and inflation. Pourbaix said he expects those costs will be covered entirely by insurance. The company said the refinery remains on track to resume normal operations in the first few months of 2023.

The lawsuit filed by contractors who were injured that day is still pending, and Findley said his clients want to see the refining industry invest in the best practices and technology at facilities nationwide to keep workers safe.

“We don’t want to see workers being put at risk. We don’t want to see communities being put at risk,” he said. “If these refineries are going to come and operate and make the money that they do, they need to also likewise spend that money to make sure that they’re protected, make sure the community is protected, and make sure that corners are not cut so things like this don’t happen.”

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