WorkSafe has agreed to amend an exemption granted to the Pike River Recovery Agency Te Kāhui Whakamana Rua Tekau mā Iwa (PRRA) from compliance with regulation 170(4)(a) of the Health and Safety at Work (Mining Operations and Quarrying Operations) Regulations 2016 (the Regulations).
The amendment to the exemption allows the PRRA to install a VCD2 seal in the mine to replace the phenolic seal that was previously installed. Once that VCD2 seal is installed, the exemption applies to re-entry and recovery of the drift up to that seal.
The reasons for the decision to grant the amendment to the exemption were that the VCD2 seal proposed to be installed:
- is considered superior in performance to the current phenolic plug, is suitable as a long term structure and is compliant with the regulations. This ensures an effective sealing of disused areas in a coalmine;
- provides a significant improvement (compared to the phenolic seal), to the control of hazards caused by the migration of methane, oxygen or noxious gases between the sealed area of a mine and the ventilated working area of the mine; and
- will increase the level of health and safety protection for workers and other persons.
The amendment also clarifies, to avoid doubt, that the PRRA may enter the area between the VCD2 seal and the roof fall, in full compliance with the Regulations.
The amendment to the exemption is made by WorkSafe in accordance with section 220 of the Health and Safety at Work Act 2015 (the Act) on the basis that WorkSafe is satisfied that:
- the extent of the amended exemption is not broader than is reasonably necessary to address the matters that gave rise to it; and
- the amended exemption is not inconsistent with the purpose of the Act.
The exemption granted on 3 December 2019 (Gazette Notice 2019-au5626(external link)) is related to the use of forced ventilation and implementation of additional measures to prevent a catastrophic event, and control any potential risks associated with the re-entry and recovery of the drift at Pike River mine.
The exemption has been granted by WorkSafe in accordance with section 220 of the Health and Safety at Work Act 2015 (the Act) on the basis that WorkSafe is satisfied that:
- the extent of the exemption is not broader than is reasonably necessary to address the matters that gave rise to it;
- the exemption is not inconsistent with the purpose of the Act.
The primary reasons for the decision were that:
- the exceptional circumstances of the Pike River mine (the mine set up and the limited scope of recovering only one mine drift) were never fully anticipated by the Regulations;
- in the Pike River mine, either an exhaust or forced ventilation would still be vulnerable in an emergency situation;
- by implementing the 27 additional controls identified in the exemption request for escaping in return air and the other controls included in the principal hazard management plans, principal control plans, trigger action response plans, and standard operating procedures, PRRA will provide an equal level of safety to workers than would be achieved by using exhausting ventilation and complying with regulation 170(4)(a) of the Regulations;
- using forced ventilation is appropriate and will provide an overall safer working environment for workers and other people by reducing or eliminating some risks (e.g. explosive or noxious gas mixture, ignition sources);
- the advantages of using forced ventilation include that:
- it provides a greater ability to scour any remnant gases in the drift as the recovery proceeds; and
- it eliminates the requirement to reticulate high voltage underground to support an auxiliary ventilation system, therefore reducing hazards in the workplace; and
- therefore Worksafe is satisfied that the criteria for the granting of an exemption under section 220(2) of the Act are met.
This exemption takes effect on 5 December 2019 and expires on 5 December 2024 unless it is sooner, replaced or revoked.