Alberta's energy regulator is examining practices at a coal mine in the province after three "instabilities" in its rock walls -- including one weeks ago that partially buried a large piece of heavy equipment and its operator.
"It buried the excavator with the operator in it," said Shayne Jessome, who works at the CST Canada Coal mine in Grande Cache, about 430 kilometres west of Edmonton.
"The guy almost got killed."
The boulders were big enough to damage the excavator's roll cage, Jessome said.
Alberta Energy Regulator spokeswoman Teresa Broughton said the company reported three "rock-wall instabilities" in June, September and October. The first was reported to the regulator on July 5 and the others on Oct. 31.
"We are assessing the conditions at the site and mitigation activities of (CST) related to these rock-wall instabilities," she said.
The three events occurred after an earlier one in the fall of 2022. Kyler Leduke was working a night shift, running a large Cat D-10 dozer deep in the mine's open pit, pushing coal toward a scoop shovel.
"Something caught my eye. I looked and I saw all this rock coming down. I thought, 'This is going to hurt.' I curled up and covered my face."
It turned out OK. The floor in the dozer's cab was ankle-deep in rock rubble but Leduke escaped unharmed.
"I was surprised I didn't have to change my ginch," he said.
A photograph provided to The Canadian Press of the dozer shows it buried up to the roof of its cab by refrigerator-sized boulders in what appears to be a mine pit.
"Inspectors have conducted site inspection and are working with CST to understand what caused these events and review any required remedial actions," Broughton said in an email. "If we find a company isn't following the rules or requirements, we'll take action by applying one or more compliance and enforcement tools."
An official with the United Mineworkers Union said Alberta's Occupational Health Services has opened at least one file on the various events, although the agency refused to comment on it.
The Canadian Press left messages seeking comment at the mine company's Calgary and overseas offices, but they were not returned.
Jessome, who was until recently the safety chairman at the mine for the union, said he has concerns about how seriously management considers safety at the mine.
Management turned down his request for monthly tours of the site to look for potential issues, he said. Requests for water trucks were denied even when dust was so thick in the mine drivers couldn't see.
When workers downed tools after Leduke's experience, Jessome said management called union officials to complain instead of addressing concerns.
Jessome described what it's like in the mine when an instability occurs in a mine wall.
"Sometimes, you can watch things start to crumble a little bit. When it's unstable, all of a sudden it just drops. It just falls, everything falls.
"When that happens, you've got to hope to Christ there's nobody working there."
Jessome said the mine relies on a radar detection system to warn of instability. But he said the people who analyze that data are remote from the site and don't give adequate warning.
The energy regulator normally releases a description of incidents it's looking into. Broughton said none were issued for the mine over the recent instabilities because "these eventsdo not meet the (regulator's) criteria for posting."
The only one of those criteria that apply to hard-rock mining refer to releases of wastewater.
CST is also under investigation by the regulator for two separate incidents in December 2022 and March of this year that saw more than 1,200 cubic metres of wastewater contaminated with coal fines released into the Smoky River.
"CST Coal has submitted a release prevention plan to the (regulator) to prevent a reoccurrence of this event in the future, and is actively implementing release prevention measures as identified in the plan, as well as ongoing and continued monitoring of the Smoky River," says the company's most recent environmental, social and governance report.
The company has since reported a third release of wastewater into the Smoky River after heavy rains flooded the site in June. The volume of that release is unknown.
"Over the past three years (including 2023), there were no reported lost days due to work injuries nor were there any work-related fatalities," the company report says. "The (company) was not aware of any non-compliance of relevant laws and regulations that have a significant impact on it relating to provision of a safe working environment and protecting employees."
CST Coal is owned by CST Group, which is based in Hong Kong and incorporated in the Cayman Islands. It bought the mine in 2017 from the receiver after the previous owner, Grande Cache Coal, went bankrupt.
The mine is both open-pit and underground, company documents say. It mines steelmaking coal, most of which is exported to Japan, Korea and China.
CST employs about 300 people in Canada.
Its leases cover almost 30,000 hectares in the northwest Alberta foothills.
This report by The Canadian Press was first published Nov. 15, 2023.
Bob Weber, The Canadian Press