Hand digging

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- (a) cutting back the walls of the excavation to reduce the height of the remaining vertical walls, if any, to no more than 1.5 metres for 'hard and compact soil' and 'likely to crack or crumble soil', - (b) installing temporary protective structures, or - (c) using a combination of the methods in clauses (a) and (b). 450 (2) Subsection (1) does not apply if a trench is constructed in solid rock throughout the entire trench. ## Cutting back walls - 451 If the walls of an excavation are cut back, an employer must ensure that - (a) if the soil is classified as 'hard and compact soil', the walls are sloped to within 1.5 metres of the bottom of the excavation at an angle of not less than 30 degrees measured from the vertical, - (b) if the soil is classified as 'likely to crack or crumble soil', the walls are sloped to within 1.5 metres of the bottom of the excavation at an angle of not less than 45 degrees measured from the vertical, and - (c) if the soil is classified as 'soft, sandy or loose soil', the walls are sloped from the bottom of the excavation at an angle of not less than 45 degrees measured from the vertical. ## Loose materials 452 An employer must ensure that loose materials are scaled and trimmed from the sides of an excavation if workers may be on or near the sides. ## Spoil piles - 453 An employer must ensure that a spoil pile is piled so that - (a) the leading edge of the pile is at least 1 metre away from the edge of the excavation, - (b) the slope of a spoil pile adjacent to the excavation is at an angle of not more than 45 degrees from the horizontal, and - (c) loose materials are scaled and trimmed from the spoil pile. ## Power pole support 454 An employer must ensure that work that disturbs the ground in the vicinity of an overhead power line is performed in a manner that does not reduce the original support provided for power line poles. ## Safe entry and exit 455 (1) An employer must ensure that if a worker is required to enter a tren…

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## Locating buried or concrete-embedded facilities 447 (1) For the purposes of subsection (1.1) and section 448, an owner means an owner or the owner's designate of a pipeline that is within 30 metres of the work site or any other buried or concrete-embedded facility that may be affected by the ground disturbance or removal of existing concrete. 447 (1.1) Before the ground is disturbed or existing concrete is removed at a work site, an employer must - (a) contact the owner, - (b) advise the owner of the proposed activities, - (c) ask the owner to identify and mark the location of the buried or concrete-embedded facility, and - (d) not begin disturbing the ground or removing the existing concrete until buried or concreteembedded facilities have been identified and their locations marked. - 447 (2) An employer must ensure that workers are aware of locate marks for buried or concrete-embedded facilities. - 447 (3) An employer must ensure that steps are taken to re-establish the locate marks for buried or concrete-embedded facilities if activities at the work site move or destroy the locate marks. - 447 (4) Despite subsection (1.1), an employer may use as built record drawings of the buried or concrete-embedded facilities for locating the buried or concrete-embedded facilities if - (a) the work does not require excavation or removal of the soil, ground or existing concrete, and - (b) the ground is penetrated to a depth of 1 metre or less or the existing concrete is penetrated to a depth of 150 millimetres or less. - (5) The as-built record drawings referred to in subsection (4) must be certified by the owner of the buried or concrete-embedded facility as the most current drawings of record that indicate the constructed location of the buried or concrete-embedded facility. ## Exposing buried facilities 448 (1) An employer must ensure that work with mechanical excavation equipment is not permitted within the hand expose zone of a buried facility until the buried faci…

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455 (2) An employer must ensure that if a worker is in a trench that is more than 1.5 metres deep, the trench is supported or sloped so that the worker can reach the safe point in order to enter and leave. ## Temporary protective structures - 456 (1) An employer must ensure that temporary protective structures in an excavation - (a) 3 metres deep or less are of sufficient strength to prevent the walls of the excavation from caving in or otherwise moving into the excavation, and - (b) more than 3 metres deep are designed, constructed and installed in accordance with the specifications of a professional engineer. - 456 (2) The specifications of a professional engineer for subsection (1)(b) must include - (a) the size and specifications of the structure, including the type and grade of materials used in its construction, and - (b) the loads for which the structure is designed. 456 (3) An employer must ensure that, before beginning an excavation, a foundation that may be affected by the excavation is supported by a temporary protective structure designed, constructed and installed in accordance with the specifications of a professional engineer. ## Alternatives to temporary protective structures 457 (1) Despite section 456, an employer may install the following as temporary protective structures in trenches: - (a) if the trenches vary in depth from 1.5 metres to 6 metres, shoring, stringers and bracing constructed of lumber that complies with Schedule 9, or a material that has equal or greater properties to those of the lumber; - (b) exterior grade plywood as a substitute for 38 millimetre shoring elements if - (i) the plywood meets the requirements of CSA Standard O121-08, Douglas Fir Plywood or CSA Standard O151-04, Canadian Softwood Plywood , - (ii) the plywood is at least 19 millimetres thick, - (iii) the trench is not more than 2.7 metres deep, - (iv) uprights are installed at intervals of not more than 600 millimetres centre-to-centre, - (v) cross braces do …

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- (b) if the buried facility is not an electrical cable or conduit, the employer ensures that - (i) it is no longer in use, and - (ii) the owner of the buried facility gives the employer written consent to excavate or remove the facility. - (c) - (e) Repealed. - 448 (3) An employer may reduce the width of a hand expose zone for a high pressure pipeline to within 1 metre on each side of the pipeline locate marks if - (a) the high pressure pipeline is not governed by the Pipeline Act , and - (b) the employer obtains written approval from the owner of the high pressure pipeline. - 448 (4) If the ground that will be disturbed lies within a pipeline right of way, an employer must - (a) contact the operator or licensee of the pipeline, and - (b) get their consent to disturb the ground. - 448 (5) An employer must not allow the use of mechanical excavation equipment within 600 millimetres of a buried pipeline unless the use of the equipment is under the direct supervision of a representative of the owner of the buried pipeline. - 448 (5.1) If an employer, on behalf of an electric utility, undertakes emergency work that - (a) involves ground disturbance to a depth of no more than 500 millimetres below the ground surface, - (b) is on the horizontal alignment or right of way of an electric utility structure, and - (c) is determined by the employer to be in a location where no buried facilities are present in the area affected by the work, the employer is exempt from the requirements of subsections (1) to (5). - 448 (6) An employer must ensure that any exposed buried facilities are protected and supported so that workers are not injured. - 448 (7) If a pipeline is exposed during a work operation, an employer must notify the pipeline operator or licensee before backfilling the excavation. ## Exemption 449 Sections 450 to 459 and sections 461 to 464 do not apply to an excavation if a professional engineer certifies that the ground formation is and will remain stable, free fro…

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- (b) it is easy to excavate with hand tools; - (c) it is solid in appearance but flows or becomes unstable when disturbed; - (d) it runs easily into a well-defined conical pile when dry; - (e) it appears to be wet; - (f) it is granular below the water table, unless water has been removed from it; - (g) it exerts substantial hydraulic pressure when a support system is used. 442 (4) If an excavation contains soil of more than one soil type, for the purposes of this Part an employer must operate as if all of it is the soil type with the least stability. ## Soil stabilization - 443 (1) Subject to subsection (2), an employer must stabilize the soil in - (a) an excavation by shoring or cutting back, or - (b) a tunnel, underground shaft or pit by shoring. - 443 (2) An employer may stabilize the soil in an excavation, tunnel, underground shaft or pit using an artificial soil stabilization technique, including freezing soil by artificial means or grouting if the process used is - (a) designed by a professional engineer to control soil conditions, and - (b) performed in accordance with the professional engineer's specifications. 443 (3) A person must not use natural freezing of the soil as an alternative or partial alternative to a temporary protective structure, or to stabilize the soil in an excavation, tunnel or underground shaft. AR 191/2021 s443;242/2022 ## Marking an excavation 444 If there is a danger of a worker or equipment falling into an excavation, an employer must ensure that workers are made aware of the excavation through flagging, marking, safeguards or other appropriate and effective means. ## Water hazard 445 An employer must ensure that an excavation that a worker may be required or permitted to enter is kept free of an accumulation of water that may pose a hazard to the worker. ## Worker access 446 (1) An employer must provide workers with a safe means of entering and leaving an excavation, tunnel or underground shaft. 446 (2) An employer must …