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Excavation Competent Person (Trenching and Excavation)
Learn the competent person's duties in excavation work: daily inspections, soil classification, protective system selection and the site hazards you control.
Based on OSHA 29 CFR 1926 Subpart P (1926.650-652 and Appendices A and B) · about 8 min read
Need proof of training? The full course (30 min) adds practice questions, a job scenario, the final quiz and a certificate your employer can verify.
A competent person is capable of identifying existing and predictable hazards and has authorization to take prompt corrective measures. That authority is the point: you can stop the work.
What you inspect
The excavation, the adjacent areas and the protective systems, looking for evidence of possible cave-ins, indications of failure of protective systems, hazardous atmospheres or other hazardous conditions.
When you inspect
Before the start of work and as needed throughout the shift
After every rainstorm or other hazard increasing occurrence
These inspections are only required when employee exposure can be reasonably anticipated
If you find a problem: where you find evidence of a possible cave-in, failure of protective systems, hazardous atmospheres or other hazardous conditions, exposed employees must be removed from the hazardous area until the necessary precautions have been taken to ensure their safety.
Employees must not work in an excavation with accumulated water, or where water is accumulating, unless adequate precautions have been taken against the hazards of water accumulation.
If water removal equipment is used to control the water, you monitor the equipment and the operation to ensure proper operation.
Excavations subject to runoff from heavy rains require an inspection by a competent person.
Soil is sorted into a hierarchy of Stable Rock, Type A, Type B and Type C, in decreasing order of stability. Appendix A applies when a sloping or benching system is designed under 1926.652(b)(2) (Option 2), when timber shoring is designed under Appendix C or aluminum hydraulic shoring under Appendix D, and when other protective systems are selected from data that relies on this soil classification system.
Each soil and rock deposit is classified by a competent person.
The classification is based on the results of at least one visual and at least one manual analysis.
In a layered system, the system is classified by its weakest layer. Each layer may be classified individually where a more stable layer lies under a less stable layer.
If anything affecting the classification changes, you evaluate the change and reclassify as necessary.
Reference: 29 CFR 1926 Subpart P Appendix A, (b) "Soil classification system" · 29 CFR 1926 Subpart P Appendix A, (c)(1) · 29 CFR 1926 Subpart P Appendix A, (c)(2) · 29 CFR 1926 Subpart P Appendix A, (c)(4) · 29 CFR 1926 Subpart P Appendix A, (c)(5) · 29 CFR 1926 Subpart P Appendix A, (a)(2)
Classifying soil
Type A, Type B and Type C
Type ACohesive soils with an unconfined compressive strength of 1.5 tsf or greater. But no soil is Type A if it is fissured, subject to vibration from heavy traffic, pile driving or similar effects, or has been previously disturbed, among other conditions.
Type BCohesive soil greater than 0.5 tsf but less than 1.5 tsf. Also, among others, granular cohesionless soils such as angular gravel, silt, silt loam and sandy loam; previously disturbed soils, except those that would otherwise be Type C; and soil that meets the Type A strength or cementation requirements but is fissured or subject to vibration.
Type CCohesive soil of 0.5 tsf or less. Also, among others, granular soils including gravel, sand and loamy sand, and submerged soil or soil from which water is freely seeping.
This page gives the headlines. The full definitions are in Appendix A. Classify from the full definitions, not this summary.
Reference: 29 CFR 1926 Subpart P Appendix A, (b) "Type A" · 29 CFR 1926 Subpart P Appendix A, (b) "Type B" · 29 CFR 1926 Subpart P Appendix A, (b) "Type C" · 29 CFR 1926 Subpart P Appendix A, (b) "Type A" (i) · 29 CFR 1926 Subpart P Appendix A, (b) "Type B" (ii) · 29 CFR 1926 Subpart P Appendix A, (b) "Type B" (iii) · 29 CFR 1926 Subpart P Appendix A, (b) "Type C" (ii)
Classifying soil
Visual and manual tests
Visual tests
Soil that stays in clumps when excavated is cohesive. Soil that breaks up easily and does not stay in clumps is granular.
Tension cracks or crack-like openings could indicate fissured material.
Manual tests
Plasticity: cohesive material can be rolled into threads without crumbling.
Thumb penetration: estimates the unconfined compressive strength of cohesive soils. Test an undisturbed sample, such as a large clump of spoil, as soon as practicable after excavation.
Pocket penetrometer or a hand-operated shearvane also give estimates.
Drying test: if the sample develops cracks as it dries, significant fissures are indicated.
Rain changes the answer. If the excavation is later exposed to wetting influences such as rain or flooding, the classification of the soil must be changed accordingly.
Reference: 29 CFR 1926 Subpart P Appendix A, (d)(1) · 29 CFR 1926 Subpart P Appendix A, (d)(2)
Protective systems
When a protective system is required
Each employee in an excavation must be protected from cave-ins by an adequate protective system. There are two exceptions:
The excavation is made entirely in stable rock.
The excavation is less than 5 feet deep and examination of the ground by a competent person provides no indication of a potential cave-in.
The protective system must have the capacity to resist without failure all loads that are intended or could reasonably be expected to be applied or transmitted to it.
Option 1: slope not steeper than one and one-half horizontal to one vertical (34 degrees measured from the horizontal).
Option 2: maximum allowable slopes and configurations determined with Appendices A and B.
Option 3: designs from written tabulated data.
Option 4: systems not using Options 1 to 3 are approved by a registered professional engineer.
Your decisions on the actual slope
The actual slope must not be steeper than the maximum allowable slope.
When there are signs of distress, it must be less steep than the maximum allowable slope: cut the slope back to an actual slope at least 1/2 horizontal to one vertical (1/2H:1V) less steep than the maximum allowable slope.
When surcharge loads from stored material, equipment or traffic are present, a competent person determines how much the slope must be reduced and assures it is.
Employees must not work on the faces of sloped or benched excavations at levels above other employees, except when those below are adequately protected from falling, rolling or sliding material or equipment.
When a design comes from manufacturer's tabulated data, any deviation from the manufacturer's specifications, recommendations and limitations is allowed only after the manufacturer issues specific written approval.
When protective system material or equipment is damaged, a competent person examines it and evaluates its suitability for continued use. If the competent person cannot assure it is able to support the intended loads or is otherwise suitable for safe use, it is removed from service and must be evaluated and approved by a registered professional engineer before being returned to service.
Removal of support systems begins at, and progresses from, the bottom of the excavation, and backfilling progresses together with the removal.
Employees must not be in a shield while it is being installed, removed or moved vertically.
The estimated location of utilities that may reasonably be encountered is determined before opening an excavation.
Utility companies or owners are contacted within established or customary local response times, advised of the proposed work, and asked to establish the location of the underground installations before actual excavation starts.
If utility companies or owners cannot respond within 24 hours (unless a longer period is required by state or local law), or cannot establish the exact location, the employer may proceed with caution and with detection equipment or other acceptable means to locate the utilities.
As operations approach the estimated location, the exact location is determined by safe and acceptable means.
Atmosphere: where oxygen deficiency (less than 19.5 percent oxygen) or a hazardous atmosphere exists or could reasonably be expected to exist, such as in landfill areas or near stored hazardous substances, test the atmosphere before employees enter excavations greater than 4 feet deep.
Egress: trench excavations 4 feet or more in depth need a stairway, ladder, ramp or other safe means of egress located so employees travel no more than 25 feet laterally.
Spoil and equipment: keep excavated materials and equipment at least 2 feet from the edge, or use retaining devices sufficient to prevent them falling or rolling in, or both if necessary.
Fact-checked against the regulation text on October 09, 2026. This certificate records completion of awareness training based on OSHA 29 CFR 1926.650, 1926.651 and 1926.652 and Appendices A and B to Subpart P. It is not an OSHA card or license, and it does not by itself make anyone a competent person under the standard. Subpart P has no training requirement of its own. Your employer must still make sure that the competent-person duties in Subpart P, such as the inspections in 1926.651(k) and any soil classification under Appendix A, are carried out by a competent person: one who is capable of identifying existing and predictable hazards and who has authorization to take prompt corrective measures to eliminate them.
This guide explains the rule in plain words. Always read the regulation itself and your employer's site-specific procedures.