156.4 (1) Before a drilling operation described in section 156.3 begins, an engineer shall, (a) design a supporting surface for the drill rig in accordance with good engineering practice to adequately support the drill rig during all drilling and drill rig set-up activities; (b) designate and design a path of travel for the drill rig to use on the project to ensure the path of travel safely supports the drill rig; and (c) prepare a written report described in subsection (2). O. Reg. 345/15, s. 19; O. Reg. 375/22, s. 5. (2) The written report required under clause (1) (c) shall include, at a minimum, details of, (a) the project and its location; (b) the designs and specifications for the supporting surface and path of travel; (c) any operating restrictions imposed by the drill rig manufacturer’s instructions, including the maximum safe ground slope for the drilling operation; (d) the existing soil conditions, all associated hazards to workers’ health and safety and the precautions to be taken to protect workers from the hazards associated with the soil conditions; (e) the minimum load-bearing capacity of the supporting surface required for each activity to be undertaken by the drill rig; (f) the surface preparation required for the supporting surface and path of travel to safely support the drill rig during its operation and travel; (g) the parts of the drill rig and the attachments of the drill rig that are permitted on the supporting surface; (h) the precautions to be taken to ensure that the drilling operation and movement of the drill rig on the path of travel, (i) do not damage or affect the stability of any building, structure, property or public way adjacent to, or in the vicinity of, the drilling operation, and (ii) do not endanger a person using any building, structure, property or public way adjacent to, or in the vicinity of, the drilling operation; (i) the frequency of inspections of the supporting surface and the path of travel of the drill rig, and the type of inspection required, to ensure they remain stable, do not deteriorate and continue to function as designed by the engineer, and any specific weather or other conditions that could affect the supporting surface or path of travel that would require additional inspections to be conducted; and (j) the qualifications of the person who conducts the inspections of the supporting surface and path of travel and whether the person needs to be an engineer, a person under the direction of an engineer, a competent worker or another person with specified qualifications. O. Reg. 345/15, s. 19; O. Reg. 375/22, s. 5. (3) The supporting surface and path of travel for the drill rig shall be prepared or constructed in accordance with the engineer’s written report. O. Reg. 345/15, s. 19; O. Reg. 375/22, s. 4. (4) No deviation from the written report is permitted unless the deviation is approved, in advance and in a written report, by an engineer. O. Reg. 345/15, s. 19; O. Reg. 375/22, s. 5. (5) The supporting surface and path of travel for the drill rig shall be inspected by an engineer after they are prepared or constructed and before the drill rig is assembled and erected on the supporting surface or uses the path of travel to confirm that they were prepared or constructed in accordance with the engineer’s report. O. Reg. 345/15, s. 19; O. Reg. 375/22, s. 3. (6) The engineer shall prepare a written report of the results of the inspection under subsection (5). O. Reg. 345/15, s. 19; O. Reg. 375/22, s. 5. (7) While a rotary foundation drill rig is in service at a drilling operation described in section 156.3, the employer responsible for the drilling operation shall ensure that, (a) the supporting surface and path of travel are regularly inspected in accordance with, and by the person identified by, the report described in subsection (2); and (b) a written report of the inspections and results are kept at the project and made available to an inspector upon request. O. Reg. 345/15, s. 19. (8) The constructor and employer responsible for the drilling operation shall keep at the project a copy of all reports described in this section and make them available to an inspector upon request until the drilling operation is completed. O. Reg. 345/15, s. 19.