Excavation & Trenching Safety: Competent Person Requirements

Why Excavation Safety Matters

Trench collapses and cave-ins are among the most lethal hazards in construction. One cubic yard of soil weighs approximately 3,000 pounds — roughly the weight of a small car. When a trench wall fails, workers have virtually no time to react. OSHA's excavation standard under 29 CFR 1926 Subpart P exists to prevent these tragedies through systematic planning, protective systems, and qualified oversight.

Between 2011 and 2022, an average of 22 workers per year died in trench-related incidents according to OSHA data. Despite this being one of the most well-understood construction hazards, violations of excavation standards continue to appear regularly on OSHA's top-cited list.

The Role of the Competent Person

OSHA's excavation standard places the competent person at the center of trench safety. This isn't a ceremonial title — it's a defined role with specific, enforceable responsibilities.

Who Qualifies as Competent?

Under OSHA's definition, a competent person for excavation work must:

• Be capable of identifying existing and predictable hazards associated with excavation work
• Be capable of identifying soil types and conditions that could affect trench stability
• Have the authority to take prompt corrective action — including stopping work — to eliminate hazards
• Understand the proper application of protective systems (sloping, shoring, shielding)

Daily Inspection Duties

The competent person must perform inspections of the excavation:

• Before each shift — Before any worker enters the excavation
• After every rainstorm — Water saturation is a leading cause of wall failure
• After any event that could increase hazard — Vibration from heavy equipment, nearby excavation, or any change in conditions

These inspections must evaluate evidence of cave-in potential, failures in protective systems, hazardous atmospheres, and other dangerous conditions. If any hazard is found, all workers must be removed until the hazard is corrected.

Soil Classification

Soil classification determines which protective systems are required. The competent person must classify soil using visual and manual tests as defined in Appendix A of Subpart P:

Protective Systems

Excavations 5 feet or deeper require a protective system unless the excavation is made entirely in stable rock. The three primary protective systems are:

Sloping

Cutting the trench walls back at an angle to prevent collapse. The angle depends on soil type. For Type C soil, walls must be sloped at 1½:1 — meaning for every foot of depth, the wall must be cut back 1.5 feet.

Shoring

Installing support structures (hydraulic, mechanical, or timber) to prevent wall movement. Shoring must be installed from the top down and removed from the bottom up.

Shielding (Trench Boxes)

Using manufactured trench boxes or shields to protect workers in the event of a wall failure. Shields must extend at least 18 inches above the surrounding grade when used in Type C soil.

Additional Excavation Requirements

• Means of egress — Ladders, steps, or ramps must be provided so that no worker has to travel more than 25 feet laterally to reach an exit
• Spoil pile placement — Excavated material must be placed at least 2 feet from the edge of the excavation
• Utility location — Underground utilities must be located before digging begins (call 811)
• Atmospheric testing — Required when hazardous atmospheres are possible (deep excavations, near landfills, contaminated sites)
• Water accumulation — Controls must be in place to prevent water accumulation in the excavation

A comprehensive excavation safety program template covers all of these requirements in a format ready for your company to customize. Supplement it with excavation JHAs and daily trench inspection forms for complete documentation.

For broader site safety coverage, see our guides on fall protection programs and daily construction inspection checklists.