Summary
In short
- Protective systems are required at five feet, and below that wherever a competent person sees potential for cave-in. Sloping, benching, shoring or shielding, selected against the soil type.
- A competent person must inspect before each shift, as needed throughout the shift, and after every rainstorm or other hazard-increasing event. Daily is the floor, not the standard.
- Excavated spoil and equipment must be kept at least two feet from the edge, because surcharge load at the lip is a direct contributor to wall failure.
- A means of egress is required within 25 feet of lateral travel in trenches four feet or deeper. In a collapse the distance to a ladder is the distance to survival.
- OSHA operates a National Emphasis Program for trenching and excavation and has stated it will consider criminal referrals where employer action or inaction kills a worker.
- Penalties reflect that posture. In April 2026 OSHA proposed nearly $4.8 million across two fatal collapse cases, including $4,699,362 against a single contractor for 57 combined willful, repeat and serious violations.
What it is
What it is
What is an excavation permit?
An excavation permit is written authorisation to break ground, recording that buried services have been located, that the soil has been classified and a protective system selected, that spoil setback and access are arranged, that atmospheric and water hazards are controlled, and that a competent person has inspected before entry.
When is a protective system required?
For any trench five feet deep or greater under 29 CFR 1926.652, unless the excavation is made entirely in stable rock. Below five feet a protective system is still required where a competent person examining the ground finds indication of a potential cave-in, so the five-foot figure is a threshold rather than a safe depth.
Who is the competent person?
Someone capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous or dangerous, and who has authorisation to take prompt corrective measures. The authority to stop work is part of the definition, not an addition to it.
When to use it
When to use it, and when not to
The permit covers ground disturbance and the entry that follows it. Several related controls sit alongside rather than inside it.
Use it for
- Any excavation, trench, pit or ground disturbance where people may enter or work adjacent
- Work near known or suspected buried services, whether or not anyone will enter
- Excavation adjacent to existing structures, roads or previously disturbed ground
- Work where atmospheric hazards are credible: near sewers, contaminated ground, landfill or fuel storage
- Any excavation requiring a change of protective system as it deepens or as conditions change
Not for
- The confined space entry permit, which applies additionally where the excavation meets the definition of a permit space
- Utility location itself, which is a separate survey activity referenced by the permit rather than performed by it
- Traffic management and road opening approvals, which are their own permissions with their own authorities
- The competent person's inspection record, which is a per-shift document generated under the permit
- Ground investigation and design, which precede the work and inform the protective system selection
Standards
What it is built against
Excavation is one of the most prescriptive areas in construction regulation, because the failure mode is well understood and the controls are well established.
| Clause | Requirement | Where it lands |
|---|---|---|
| 1926.651(b) | Utility installations located and, where reasonably practicable, supported or removed before excavation | Gate 1 Buried services |
| 1926.652(a)(1) | Protective system for excavations five feet or deeper, or at any depth with indication of potential cave-in | Gate 2 Excavation safety |
| 1926.652(b) | Sloping and benching designed in accordance with soil classification and the standard's appendices | Gate 2 Excavation safety |
| 1926.651(j)(2) | Spoil, materials and equipment kept at least two feet from the edge, or retained | Gate 2 Excavation safety |
| 1926.651(c)(2) | Means of egress within 25 feet of lateral travel in trenches four feet or deeper | Gate 2 Excavation safety |
| 1926.651(k)(1) | Competent person inspection before each shift, as needed during the shift, and after every rainstorm | Authorisation |
| 1926.651(g)(1) | Atmospheric testing where hazardous atmosphere could reasonably be expected, deeper than four feet | Gate 3 Atmosphere |
| 1926.651(g)(2) | Emergency rescue equipment available where hazardous atmospheric conditions exist or may develop | Gate 3 Rescue |
| 1926.651(h) | Protection from water accumulation, including removal and monitoring by a competent person | Gate 2 Excavation safety |
What it does not cover
- Confined space entry permit, required additionally where the excavation meets the permit space definition and the atmosphere or configuration warrants it.
- Utility location survey, which is a separate activity whose results the permit records rather than produces.
- Protective system design for excavations over twenty feet, which requires a registered professional engineer.
- Traffic management and highway permissions, which are separate approvals from separate authorities.
- The per-shift competent person inspection, which is generated under the permit and recorded per inspection rather than per excavation.
Filling it in
Filling it in well
An excavation permit is a sequence of gates, each of which corresponds to a recurring fatality mechanism.
Drawings are a starting point and are frequently wrong, particularly on sites with a long history of alterations. Detection survey, then careful hand digging or vacuum excavation to expose the service, then physical marking. Strike incidents almost always trace to a drawing that was trusted rather than verified, and the consequence ranges from an outage to an explosion.
The protective system selection depends on soil type, and soil type is a competent person judgement made on site with a manual and visual test. Recording the classification and the person who made it turns the protective system from an assumption into a decision with reasoning behind it, which is what an investigator will look for.
The requirement is before each shift, as conditions warrant during the shift, and after every rainstorm or other hazard-increasing event. A single inspection at the start of a week-long job does not satisfy it. Rain is the trigger most often missed, and it is the one most closely associated with collapse.
Spoil migrates toward the edge as the day goes on, and equipment gets parked where it is convenient. Both add surcharge load at the point where the wall is weakest. Egress within 25 feet of lateral travel means a ladder that is present, secured and extends above the surface, not one that was there this morning.
Audit findings
Common audit findings
Excavation findings are notable for how consistently they involve the total absence of a control rather than an inadequate one.
| Finding | Clause | What fixes it |
|---|---|---|
| No protective system in a trench five feet or deeper. | 1926.652(a)(1) | Nothing enters the trench until the system is installed; this is the mechanism in nearly every fatality. |
| Protective system available on site but not installed. | 1926.652(a)(1) | Make installation a gate on the permit, verified physically before entry is authorised. |
| No competent person inspection before the shift, or no record of one. | 1926.651(k)(1) | Record per shift with the inspector named; a per-excavation record does not satisfy the standard. |
| No inspection after rainfall despite conditions changing. | 1926.651(k)(1) | Make weather an explicit trigger; rain is strongly associated with subsequent collapse. |
| Spoil or equipment within two feet of the edge. | 1926.651(j)(2) | Mark the setback physically; spoil migrates during the day and nobody notices. |
| No ladder or ramp within 25 feet of lateral travel. | 1926.651(c)(2) | Position egress before entry; in a collapse the distance to a ladder decides the outcome. |
| Services struck because drawings were relied on without verification. | 1926.651(b) | Detect, expose and mark; drawings are an input, not a location. |
| Atmosphere not tested where a hazardous atmosphere could reasonably be expected. | 1926.651(g)(1) | Test where the excavation is over four feet and the ground or surroundings suggest risk. |
| Soil classification not performed or not recorded, so system selection has no basis. | 1926.652(b) | Record the classification, the test used and the person who made it. |
| Excavation over twenty feet without a protective system designed by a professional engineer. | 1926.652(b)(4) | Engineered design is mandatory above twenty feet, not a matter of preference. |
Worked case
Case in point: the shield beside the trench
In June 2022 two workers aged twenty and thirty-nine were killed in Jarrell, Texas, when an unprotected trench more than twenty feet deep collapsed on them. Trench shields that could have saved them were on site, sitting unused beside the excavation.
That case became part of the impetus for OSHA's enhanced enforcement posture on trenching, including the statement that it would consider criminal referrals where employer action or inaction kills a worker, and a commitment to more than a thousand random trench inspections nationwide under its National Emphasis Program.
The pattern has not changed since. In April 2026 OSHA announced two fatal collapse cases with nearly $4.8 million in combined proposed penalties, one of them $4,699,362 against a single contractor for 57 willful, repeat and serious violations. In both, workers had been sent into unprotected trenches.
Definitions
Definitions and key terms
- Competent person
- Someone able to identify existing and predictable hazards and authorised to take prompt corrective measures, including stopping work.
- Protective system
- Sloping, benching, shoring or shielding used to prevent cave-in, selected against soil classification and depth.
- Soil classification
- Stable rock, Type A, B or C, determined by a competent person using manual and visual tests, governing the system selected.
- Surcharge load
- Weight applied near the excavation edge from spoil, equipment or vehicles, which increases the force on the wall.
- Spoil setback
- The minimum two feet between excavated material and the edge, required to limit surcharge and prevent material falling in.
- Benching
- Cutting the sides into horizontal steps with vertical faces between. Not permitted in Type C soil.
- Shielding
- A trench box or shield protecting workers from cave-in without preventing the collapse itself.
- Hazard-increasing event
- Rain, vibration, adjacent excavation, water accumulation or any change requiring a fresh competent person inspection.
FAQ
Frequently asked questions
At what depth is a protective system required?+
Five feet or deeper under 1926.652(a)(1), unless the excavation is entirely in stable rock. Below five feet a system is still required where a competent person finds indication of a potential cave-in. Fatalities have occurred in trenches shallower than five feet, so the figure is a mandatory threshold rather than a depth at which the ground becomes safe.
How often must the excavation be inspected?+
By a competent person before each shift, as needed throughout the shift, and after every rainstorm or other hazard-increasing event. The record should be per inspection rather than per excavation, which is a common gap: a job running a week generates one inspection record where it should generate five or more.
How far must spoil be kept from the edge?+
At least two feet, or it must be retained by a device sufficient to prevent it falling in. The setback also limits surcharge load on the wall. In practice spoil migrates toward the edge through the day and equipment is parked where convenient, which is why marking the line physically works better than stating it.
Do we always need to test the atmosphere?+
Where a hazardous atmosphere exists or could reasonably be expected in excavations deeper than four feet: near landfill, contaminated ground, sewers, fuel storage or where hazardous substances are stored nearby. Where atmospheric hazards exist or may develop, emergency rescue equipment must be available and attended.
What is OSHA's enforcement posture on trenching?+
Markedly more aggressive than in most areas. There is a standing National Emphasis Program, compliance officers may inspect any excavation site they encounter, and OSHA has stated it will consider criminal referrals where employer acts or omissions kill workers. Penalty levels reflect this: in April 2026 two fatal collapse cases drew nearly $4.8 million in proposed penalties combined.
When is an engineer required?+
Protective systems for excavations deeper than twenty feet must be designed by a registered professional engineer. Tabulated data may be used below that depth within its stated limits, but those limits are specific and using tabulated data outside its scope leaves the system without a valid design basis.
The agents
What the agents do with it
The permit is a set of gates. What fails is the gap between the system being available and being installed, and the inspection that was performed once for a job that ran all week.
Issues the permit against gates that must be physically verified, holds the per-shift inspection requirement, and reopens the inspection automatically after recorded rainfall.
Verifies competent person qualification and contractor competency before a permit is issued, and links the permit to named individuals rather than to a company.
Cross-references interacting permits where the excavation is also a confined space, and holds them open and closed together.
Connects the excavation to the asset and the buried services register, so a strike updates the record that the next crew will rely on.
This template lives in KnowSafe — safety and compliance. Incidents, hazards, permits, inspections and the critical controls behind them.
Meet KnowSafe→Sources
Sources
- 29 CFR 1926 Subpart P, excavations, particularly 1926.651 and 1926.652, OSHA
- OSHA National Emphasis Program on Trenching and Excavation, CPL 02-00-161
- OSHA trenching and excavation overview and guidance
- NIOSH trenching and excavation safety guidance
- US Department of Labor news release on enhanced trenching enforcement