Pike River receiver PwC met with representatives of the company and rescue teams to assess a suitable re-entry timetable and plans to finalise stabilisation work at the mine.

The mine’s CO levels have fallen from about 6000 parts per million to below 1350ppm, bringing it close to the safe level of 1200ppm.

PwC’s John Fisk said oxygen levels in the mine were also rising and any decision to re-enter the mine would need to be approved by an expert panel, which included the Department of Labour and Mines Rescue.

Last month PwC reported gas levels, “mainly carbon monoxide”, had risen to such an extent that the mine was unstable.

Sealing work around the ventilation shaft has been completed since.

“It is believed this has contributed to a decrease in gas levels and it is hoped this trend will continue,” PwC said.

“However, changes in the atmospheric conditions in the area are also expected to impact on gas levels in the mine.”

Other preparations are underway to set up the equipment needed for the new portal configuration, including electrical lines and compressors.

The latest mine stabilisation effort is centred on a staged re-entry of the mine. The first step is to place airtight steel double doors at the portal.

But there is always a possibility of more delays ahead.

“The situation is being assessed daily by Pike River mine management in consultation with the New Zealand Mines Rescue Service, gas experts and the expert panel established by the receivers,” Fisk said.

“Safety is our first priority and in this regard we will not allow the work in the portal to commence until we have sign-off from Mines Rescue and the other experts.

“We will continue to provide weekly reports on the status of the mine to the families of the 29 men and will continue to provide updates on any further developments.”