A loader operator is trenching for a utility line in clay soil. The trench is 1.5 m deep. According to provincial occupational health and safety regulations for trenching without shoring or sloping, what is the maximum permissible length of an open trench at any one time?

Question: A loader operator is trenching for a utility line in clay soil. The trench is 1.5 m deep. According to provincial occupational health and safety regulations for trenching without shoring or sloping, what is the maximum permissible length of an open trench at any one time?

Answer options:

• There is no maximum length, only depth and width restrictions.
• The regulations typically specify a maximum open length of 30 m. ✅ The regulations generally limit the open trench to the length required for immediate work and backfill.
• The maximum length is determined by the size of the loader being used.

Correct answer: The regulations generally limit the open trench to the length required for immediate work and backfill.

Explanation: Provincial OH&S regulations, such as those in Ontario (O. Reg 213/91 Construction Projects), generally require that unshoring or unsloped trenches be kept to the minimum length necessary for the work, and backfilled as soon as possible, rather than a specific maximum numeric length. This minimizes exposure to potential collapse.