We Energies was cited for two willful violations of failing to provide the contractors adequate safety information. Each citation carries a proposed penalty of $70,000.
The utility was also cited for one serious violation of failing to provide certain safety information about the area where the work was being done. That violation carries a proposed penalty of $7,000, for a total fine of $147,000.
The contractor, Waukesha-based ThyssenKrupp Safway Inc., faces $153,500 in citations stemming from two willful violations and five serious violations. A willful violation is OSHA's most egregious classification where evidence shows there was intentional disregard or indifference to the agency's standards. A serious violation is a lesser classification applied to actions that could cause death or serious injuries.
Companies often get fines lowered if they make changes to eliminate violations or otherwise comply with regulations in the future, OSHA spokesman Scott Allen said.
Brian Manthey, a spokesman for We Energies, said the company was looking over the OSHA report and planned to meet with investigators in coming days to discuss the violations and next steps.
"We've been looking into the cause ourselves. This will help in terms of us doing our own internal work," Manthey said.
The contractors were working inside the coal-dust silo, a tower used to collect leftover coal dust that gets burned to produce power, when the explosion occurred. It caused more than $1 million in damage, Manthey said.
The blast left two workers with burns on half their bodies, and four others were hospitalized with second- and third-degree burns.
Seven workers, plus the wives of two victims, are suing We Energies and its insurance companies. They accuse the utility of failing to provide a safe workplace and being negligent in keeping the silo clean of coal dust. The lawsuit seeks unspecified damages in excess of $5,000, as well as punitive damages.
Their lawyer said the citations weren't relevant to the charges he planned to prove. But if We Energies suddenly begins making improvements to its safety program, that could help his case, Timothy Trecek said.
"What they do after the accident is admissible to show what they could have done before," Trecek said.
Manthey declined to discuss the litigation. When asked whether the pending litigation would affect the utility's decision to implement any improvements, he said it was difficult to deal with hypothetical situations and that We Energies is keeping its focus on safety.
"We're always looking for ways to improve," he said. "Our number-one priority is always safety."
OSHA cited ThyssenKrupp Safway for two willful violations of failing to implement adequate safety procedures and failing to verify safety conditions. It also alleged five serious violations including failure to provide proper fire-retardant clothing and failure to provide proper training.
All the injured workers have been out of the hospital for months and are recovering, ThyssenKrupp spokeswoman Michelle Dalton said. She declined to say whether any had returned to work or whether the company was still contracting with We Energies.
"I can tell you we have received OSHA's citations for alleged violations and we'll be reviewing them closely," she said.
Both companies have until August 19 to respond to the citations.
The OSHA report didn't indicate a cause of the explosion. Allen said the agency's role is to ensure compliance with safety regulations, and that it's up to the companies to determine cause.
The utility provides electricity for more than 1.1 million customers in Wisconsin and Michigan and supplies natural gas to more than 1 million customers in Wisconsin. The Oak Creek plant, which sits along Lake Michigan, burns 5,000 to 10,000 tons of coal per day.