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Guidelines Part 22 Contents


  G22.2(2) Application of Part 22 (Underground Workings)


  G22.12 Underground supervisor's certificate [Retired]

Guidelines Part 22 - General requirements

G22.2(2) Application of Part 22 (Underground workings)

Issued June 18, 2008

Regulatory excerpt
Section 22.2 (Application) of the OHS Regulation ("Regulation") states:

(1) This Part applies to any underground working which is not a mine within the meaning of the Mines Act, or the Health, Safety and Reclamation Code for Mines in British Columbia, and which a worker will be required or permitted to enter.

(2) Generally, this Part does not apply to horizontal underground workings that are less than 5 m (16 ft) in length or to permanent facilities in their final structural condition as certified by a professional engineer.

In turn, "underground working" is defined in section 22.1 as including:

any adit, tunnel, underground excavation, chamber, caisson, raise, shaft, winze or natural entry

Purpose of guideline
This guideline discusses the circumstances, under section 22.2 of the Regulation, in which an underground working can be considered to be a permanent facility in its final structural condition as certified by a professional engineer.

The guideline also provides information on the application of the Regulation to underground projects that have been completed.

Permanent facilities in their final structural condition
Section 22.2(2) exempts the application of Part 22 to a permanent facility in its final structural condition as certified by a professional engineer. In order for an underground working to be in its final structural condition, it needs to be structurally capable of being used safely for its intended purpose(s). There are several aspects to this exception that need to be considered.

An underground working will not be in its "final condition" until the drilling, blasting, boring, or digging sequence is finished, along with the associated walls, roof, and invert. This will include all structural rock bolts, mesh, straps, steel supports, and shotcrete necessary to support a structure. However, the reference to "permanent facility in its final structural condition" has a somewhat broader meaning than the more limited reference to "final condition."

Hazards to workers in underground workings include aspects such as atmosphere, lighting, and potential for fire. If the project involves the replacement of temporary ventilation and lighting systems by permanent systems, the project will not be considered to be in final structural condition or structurally complete until that is done. The potential for fire is related in part to the use of heavy equipment involved in excavation, but which may also be used in other project work such as completion of an underground road or rail bed. Completion of such work, where applicable as part of the project, will typically be necessary before the facility is considered to be structurally complete. An underground project may also include other elements such as transitions, underground control gates, and control stations.

In some cases, an underground working may involve a series of tunnels or other excavations. Steps to complete the project may include sealing one or more of these areas by means such as walls, plugs, or backfill, and installation of drainage systems within the underground working. These steps will need to be completed before an underground working can be considered to be in its final structural condition.

As required by section 22.2(2), a professional engineer must certify that the facility is in its final structural condition. A certificate that addresses only part of the facility is not a sufficient basis for applying the exception.

Application of the Regulation to an underground project that has been completed
If an underground working has been completed under the terms of section 22.2(2), Part 22 no longer applies, but the other requirements of the Regulation remain in effect to address any subsequent work that may be done at the site.

Examples of such work include operation of underground control devices, use of worker transport systems, and equipment or facility inspections, maintenance, and repair.

Applicable requirements will include those of Part 9 (Confined Spaces) for work in any space that meets the definition of a confined space in section 9.1 of the Regulation.

Guidelines Part 22 - Supervision of workers

G22.12 Underground supervisor's certificate

Issued April 27, 2010; Retired consequential to May 1, 2017 regulatory amendment

Disclaimer: The Workers' Compensation Board of B.C. ("WorkSafeBC") publishes the online version Occupational Health and Safety Regulation ("OHS Regulation") in accordance with its mandate under the Workers Compensation Act to provide information and promote public awareness of occupational health and safety matters. The online OHS Regulation is not the official version of the OHS Regulation, which may be purchased from Crown Publications. WorkSafeBC endeavours to update the online OHS Regulation as soon as possible following any legislative amendments. However, WorkSafeBC does not warrant the accuracy or the completeness of the online OHS Regulation, and neither WorkSafeBC nor its board of directors, employees or agents shall be liable to any person for any loss or damage of any nature, whether arising out of negligence or otherwise, arising from the use of the online OHS Regulation. Employers are legally obligated to make a copy of the Workers Compensation Act and the OHS Regulation readily available for review by workers. The circumstances under which WorkSafeBC may consider an employer's providing access to electronic versions of the Act and OHS Regulation to have satisfied this obligation are described in Guideline G-D3-115(2)(f).