An excavator operator is tasked with digging a trench near a concrete wall that is part of an existing structure. The engineer's report indicates the wall's foundation is 1.5 m deep. The planned trench is 2.0 m deep and will beParallel to the wall, 1.0 m away. What is the primary trenching and excavation hazard to consider in this scenario, and what control measure is necessary?

Question: An excavator operator is tasked with digging a trench near a concrete wall that is part of an existing structure. The engineer's report indicates the wall's foundation is 1.5 m deep. The planned trench is 2.0 m deep and will beParallel to the wall, 1.0 m away. What is the primary trenching and excavation hazard to consider in this scenario, and what control measure is necessary?

Answer options:

• The primary hazard is striking underground utilities; obtain additional locates. ✅ The primary hazard is undermining the existing wall's foundation; shoring or sloping specific to the wall's stability is required.
• The primary hazard is worker fall protection; ensure guardrails are installed around the trench.
• The primary hazard is noise pollution; implement hearing protection for all workers.

Correct answer: The primary hazard is undermining the existing wall's foundation; shoring or sloping specific to the wall's stability is required.

Explanation: The primary hazard when excavating near an existing structure's foundation, especially when the trench depth exceeds the foundation depth and is close to it, is undermining the foundation, which can lead to structural collapse. Specific shoring, sloping, or other engineering controls to support the wall's foundation are essential in this situation. While other hazards might exist, undermining is the most critical and direct risk posed by this specific excavation plan.