CSLB Law & Business ExamSafetyHard
A contractor is excavating a trench that will reach 22 feet in depth to install a large storm drain pipe. What additional requirement applies beyond standard shoring for shallower trenches?
- AThe trench must be excavated only using hand tools
- BThe protective system must be designed by a registered civil or structural engineer
- CA lifeguard must be present at all times during excavation
- DNo additional requirement; standard shoring rules apply the same at any depth
Show answer & explanationAnswer & explanation
Correct answer: B. The protective system must be designed by a registered civil or structural engineer
Cal/OSHA regulations require that protective systems for excavations deeper than 20 feet be designed by a registered professional engineer, due to the increased structural and soil-stability risks at greater depths.
Why the other options are wrong
- A. Hand-tool-only excavation is not a regulatory requirement tied to depth.
- C. Lifeguards are irrelevant to trench excavation safety requirements.
- D. Deeper trenches (over 20 ft) carry heightened design requirements beyond standard shoring tables.
Deep Excavation Engineering Requirement
Excavations deeper than 20 feet require a protective system designed by a registered professional engineer under Cal/OSHA standards.
- 20-foot threshold triggers engineer design requirement
- Standard tabulated data no longer sufficient beyond 20 feet
- Reflects increased cave-in and structural risk at depth
Memory trick: Past twenty feet, call the engineer's seat