Trenches can fail without warning. Soil that appears stable can collapse after vibration, water intrusion, weather changes, nearby loading, or removal of material. Before any employee enters, the employer should confirm that hazards have been evaluated and required protective measures are in place.

The competent person plays a central role in identifying existing and predictable hazards and taking prompt corrective action.

Locate underground installations
Before excavation begins, contractors should identify utilities and other underground installations. Marking services, owner information, potholing, and other verification methods may be needed to confirm actual location and depth.

The plan should address electrical, gas, water, sewer, communication, and unknown lines, along with emergency procedures for a strike or leak.

Classify soil and select protection
The protective system should be based on soil conditions, depth, water, adjacent structures, vibration, surcharge loads, and the work being performed. Sloping, benching, shoring, and shielding are not interchangeable, and tabulated data or engineered designs must be followed when used.

Employees should never work outside the protected area of a trench shield or remain in a shield while it is being moved unless specifically allowed by the system and procedure.

Provide safe access and egress
Ladders, ramps, stairs, or other safe means of access should be positioned so employees can exit quickly. Access routes must remain clear and should not require workers to climb over utilities or equipment.

Structural ramps used by employees must be designed by a competent person, and equipment ramps require appropriate structural design competence.

Control spoil, equipment, water, and atmosphere
Spoil piles, materials, and equipment should be kept far enough from the edge or restrained so they do not fall into the excavation or add unsafe loading. Mobile equipment near the edge may require barricades, stop logs, or signaling systems.

Water accumulation, hazardous atmospheres, nearby traffic, falling material, and adjacent structures must also be evaluated. Testing and ventilation may be required where atmospheric hazards could exist.

Inspect as conditions change
Inspections should occur before work, as needed throughout the shift, and after rain, vibration, or any event that could increase hazards. Employees should leave the excavation when the competent person identifies a dangerous condition.

How EA Safety Services can help
EA Safety Services, LLC can review excavation plans, competent-person procedures, permits, protective-system documentation, and field conditions before entry.