CENTENNIAL Coal failed to evacuate up to 100 underground workers when deadly gases flooded its Mandalong Mine at Lake Macquarie last week.
Several workers told Fairfax Media they were “completely oblivious” and “lucky to be alive” after the methane gas level reached a “near-explosive reading” on Tuesday, September 5.
According to workers, an underground tractor struck a gas drainage pipe, flooding the mine with gas.
The NSW Resources Regulator shutdown the underground operation the following day.
It is understood up to 100 miners were underground at the time and most had no idea about the gas leak.
Many were not informed until they were told by their supervisors not to return to work for their next shift.
“We could have died, it's an absolute disgrace,” a miner said.
“There are rules and regulations in place to govern this type of thing to keep workers safe.
“We should have been pulled out immediately. It’s unbelievable this was allowed to happen.”
A Department of Planning and Environment spokesman said all workers were prohibited from going underground for eight days, with exception of those doing safety-related work.
The ban was lifted on Wednesday afternoon.
Workers told Fairfax Media this was the second gas “incident” at the mine this year.
The department spokesman confirmed that before last week’s gas leak, inspectors had already commenced a “targeted intervention” at the mine.
He said investigations were continuing and the Resources Regulator could require further action from the mine “to address compliance issues as part of that ongoing intervention”.
Under the mine’s safety plan it is required to “immediately” withdraw underground workers when methane levels reach three per cent.
Methane gas levels reached 3.5 per cent at Mandalong on September 5 and workers were not evacuated.
Explosive methane levels are between five and 15 per cent.
A Mandalong worker said operations should have ceased immediately and the mine evacuated to reduce the risk of ignition.
“It just didn’t happen and we are at a loss to know why,” he said.
“They just didn’t evacuate the mine and most people knew nothing about it until later. It raises a lot of questions about what went wrong. We are talking about risking peoples’ lives.”
It’s understood the mine failed to follow it’s own “trigger action response plan”, which is part of the Major Hazard Management Plan that sets out guidelines for worker safety.
The department spokesman said normal operations at the mine resumed on Wednesday afternoon.
“Following an investigation into the cause and circumstances of the incident by the mine, the Resources Regulator is satisfied that appropriate risk controls have been put into place to ensure workers at the mine are not exposed to an unacceptable level of risk,” he said.
In a brief statement, Centennial Coal's spokeswoman said the mine's priority was “the safety of our people in what can be a challenging underground environment”.
“We are working with the regulator to ensure all our systems and processes reflect the highest of standards,” she said.
The mine, located near Morisset, employs more than 400 people, producing up to 6.5 million tonnes of coal a year.
It predominately supplies Hunter power stations and has approval to continuing mining for another 20 years.
The Construction, Forestry, Mining and Energy Union did not respond to requests for comment.