Post sponsored by NewzEngine.com

Source: New Zealand Government

The next phase of the Pike River Re-entry project is underway, Minister Responsible for Pike River Re-entry Andrew Little says.

“Fresh air will be pumped into the Pike River Mine drift this week, following acceptance of the plan for re-entry beyond the 170m barrier by New Zealand’s independent health and safety regulator WorkSafe.

“The Pike River Recovery Agency has planned a safe, manned re-entry and recovery of the drift past the 170m barrier, with input from local and international experts. The next step is advancing safely up the remainder of the 2.3km drift and carrying out forensic examinations along the way.

“This Coalition Government is delivering on its promise to the Pike River families and all New Zealanders. We need to find out as much as possible about what caused 29 men to go to work and not come home. The safe recovery of the mine drift, and its forensic examination, is part of an overdue act of justice.

“As previously announced, the plan includes an exemption to one aspect of mining regulations[1] which has been approved by WorkSafe under existing law[2]. The Agency was required to demonstrate its plan was as safe or safer than the regulation.

“Now the Agency will proceed with what it considers to be the best and safest way to ventilate the drift.

“This is welcome Christmas news for the families, for the Agency’s staff, and all New Zealanders,” Andrew Little said.

Background notes

In September 2019 the Pike River Recovery Agency lodged an application for an exemption with WorkSafe, including two main documents (Exemption application and Execution plan) and several supporting documents.

There had been months of work deciding on the best methods to re-enter the drift safely, drawing on expertise from world leaders in mining and ventilation. 

The Agency received WorkSafe’s preliminary decision on the exemption application last Friday, and it supports the Agency’s Re-entry and Ventilation plans through to the Rocsil plug near the roof fall. An exemption notice was required because its plans differed from what is legislated, and all parties now agree the Agency’s plans are safe.

The Agency has been preparing for WorkSafe’s decision, and plans to breach the 170m barrier before Christmas, if possible.

How will you control the atmosphere in the mine drift when you remove the 170m barrier?

The Agency’s Final Gas Management and Ventilation Plan (2019) provides for a number of ventilation control devices (VCDs). The first, a Rocsil “plug” remotely inserted using boreholes close to the roof fall was completed in early November; with two other confirmed VCDs (and possibly more) planned for the future – one inbye Pit Bottom in Stone – this seal will provide a stable atmosphere for an extensive investigation of the hundreds of metres of tunnel and mining infrastructure housed in the pit bottom in stone area; and the second just outbye the Rocsil plug. 

I want to understand in detail how you’re planning to ventilate the mine with fresh air?

That information will be updated on the Agency website as soon as the exemption decision has been gazetted by WorkSafe. Search “ventilation” at www.pikeriverrecovery.govt.nz.

How long will the project take?

The project is event-driven rather than time-driven, and will be done safely. There are still significant unknowns.

What were the documents submitted to WorkSafe on Friday 13 September?

  • Ventilation and Gas Management Plan
  • Entry and Exit Execution Plan
  • Pike River Mine Drift Re-entry Geotechnical Assessment
  • Application for exemption from Regulation 170 (4) (a) of the Health and Safety at Work Mining Operations and Quarrying Operations Regulations 2016
  • Force vs Exhaust Ventilation Risk Assessment
  • Mine Entry and Exit Risk Assessment
  • Emergency Management Principal Control Plan
  • Single Entry Principal Hazard Management Plan

These documents will also be available on the Pike River Recovery Agency website after the exemption decision has been gazetted by WorkSafe.

Why did the Agency require an exemption?

Regulation 170 (4) (a) of the Mining Operations and Quarrying Regulations 2016 requires that there must always be an ability for workers to escape from a mine in an intake airway.  The Agency sought an exemption to use a process called ‘forced ventilation’ in which fresh air is forced by a fan to the working space through a duct and then the air flows back (called return air) through the roadway to the entrance of the mine.

The Agency considers, based on advice it has received, that this approach is the best and safety option for the project.

WorkSafe undertook a detailed review of the Agency’s exemption request and determined that worker health and safety outcomes were at least equivalent to the outcome of adhering to the regulation itself. WorkSafe was satisfied that the PRRA request met all legislative requirements for the granting of an exemption.

MIL OSI