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Excavation and Trenching Safety Program

Document Type: Program
Version: 1.0
Last Updated: February 2026
Distribute To: Excavation Crews, Superintendents, Competent Persons

Purpose​

Establish procedures for safe excavation and trenching operations to prevent cave-ins and other hazards that cause serious injuries and fatalities.

⚠️ CRITICAL INFORMATION​

Excavation Hazards Kill​

  • Cave-ins are the greatest hazard
  • One cubic yard of soil = 2,700-3,000 lbs
  • Death can occur in minutes
  • Most fatalities involve trenches 5-15 feet deep

OSHA Requires Protection at 5 Feet​

Protective systems required for excavations 5 feet or deeper (unless in stable rock)

Definitions​

TermDefinition
ExcavationAny man-made cut, cavity, or depression in the earth
TrenchA narrow excavation (depth > width, width ≤ 15 feet)
Competent PersonOne who can identify hazards and has authority to take corrective action
Protective SystemMethod to protect employees from cave-ins

Competent Person Requirements​

Who is the Competent Person?​

A person who:

  • Can identify existing and predictable hazards
  • Can classify soil properly
  • Can select appropriate protective systems
  • Has authority to stop work

Competent Person Duties:​

  • Inspect excavations daily (and after events)
  • Classify soil type
  • Select protective system
  • Monitor conditions
  • Stop work if unsafe

Training Requirements:​

  • OSHA excavation requirements
  • Soil classification methods
  • Protective system selection
  • Hazard recognition
  • Document training

Pre-Excavation Requirements​

Before Any Digging:​

1. Call 811 (Utility Locate)

  • Required by law
  • Call at least 2 working days before
  • Wait for all utilities marked
  • Maintain marks during work

2. Review Plans

  • Known underground utilities
  • Previous construction
  • Adjacent structures
  • Site history

3. Site Assessment

  • Surface conditions
  • Adjacent structures/roads
  • Water sources
  • Weather forecast

4. Plan the Work

  • Location of spoil pile
  • Access and egress
  • Equipment positioning
  • Traffic control
  • Protective system selection

Soil Classification​

Competent Person Must Classify Soil​

Classification Types:

TypeDescriptionCharacteristics
Stable RockSolid mineralNo protective system required
Type AMost stable soilClay, silty clay, hardpan
Type BMedium stabilitySilt, sandy loam, previously disturbed
Type CLeast stableGravel, sand, submerged soil, running

Classification Methods:​

  • Visual tests
  • Manual tests (thumb penetration, dry strength)
  • Consider water, vibration, prior disturbance

When in Doubt:​

  • Classify as Type C
  • Use maximum protection

Protective Systems​

Required When Depth ≥ 5 Feet​

Four Options:

1. Sloping​

Cut back trench walls to angle safe from cave-in

Soil TypeMaximum Slope
Stable RockVertical
Type A¾:1 (53°)
Type B1:1 (45°)
Type C1½:1 (34°)

2. Benching​

Series of horizontal levels with vertical sides

  • Type A only (not Type B or C alone)
  • Maximum bench height: 4 feet
  • Combined with sloping

3. Shoring​

Hydraulic, timber, or mechanical systems

  • Shores support trench walls
  • Must be designed for soil type
  • Install/remove from outside trench

Types:

  • Aluminum hydraulic shores
  • Timber shoring
  • Pneumatic shores

4. Shielding (Trench Box)​

Protects workers inside the shield

  • Does NOT prevent cave-in
  • Protects workers WITHIN shield
  • Must extend above bottom of excavation
  • Rated for depth and soil type

Protective System Selection Table​

DepthType AType BType C
0-4 ftNone required*None required*None required*
5-20 ftSlope, shore, or shieldSlope, shore, or shieldSlope, shore, or shield
over 20 ftPE designed systemPE designed systemPE designed system

*Protection may still be required if hazards present

Daily Inspection Requirements​

Competent Person Inspects:​

Before Each Shift:

  • Soil conditions
  • Protective system integrity
  • Adjacent structures
  • Surface water/drainage
  • Underground utilities
  • Spoil pile location

After Any of These:

  • Rain or water intrusion
  • Vibration (equipment, traffic)
  • Change in soil conditions
  • Adjacent work
  • Any incident

Remove Workers If:​

  • Signs of potential cave-in
  • Water accumulation
  • Protective system damage
  • Hazardous atmosphere detected

Access and Egress​

Requirements:​

  • Exit within 25 feet of all workers
  • Ladders, steps, or ramps
  • Ladders extend 3 feet above landing
  • Multiple exits for long trenches

Ladder Placement:​

  • Set at proper angle (4:1 ratio)
  • Secured at top or bottom
  • Extend 3 feet above edge
  • Never in spoil pile

Spoil Pile Requirements​

Keep Materials Back:​

  • Minimum 2 feet from edge
  • Or use retaining device
  • Never place at edge

Other Materials:​

  • Equipment set back from edge
  • Traffic kept at safe distance
  • Barriers if necessary

Water Hazards​

Water Control:​

  • Divert surface water
  • Dewater as needed
  • Monitor constantly when water present

When Water Present:​

  • Competent person evaluates
  • Additional bracing may be needed
  • Pump water away from excavation
  • Never enter submerged excavation

Hazardous Atmospheres​

Test When:​

  • Depth > 4 feet
  • Known or suspected contamination
  • Adjacent to hazardous operations
  • Visible water/seepage

Test For:​

  • Oxygen (19.5% - 23.5%)
  • Flammable gases (< 10% LEL)
  • Carbon monoxide
  • Hydrogen sulfide (if suspected)

If Hazardous:​

  • Ventilation required
  • Respiratory protection
  • Rescue equipment available
  • Confined space entry may apply

Excavation Safety Checklist​

Pre-Work:​

  • Utility locate completed (811)
  • All utilities identified and marked
  • Competent person designated
  • Soil classification planned
  • Protective system selected
  • Equipment in good condition
  • Access/egress planned

Daily:​

  • Competent person inspection completed
  • Protective system in place
  • Access within 25 feet
  • Spoil pile 2+ feet from edge
  • Surface water controlled
  • Adjacent structures stable
  • Traffic control in place

After Rain/Events:​

  • Re-inspection completed
  • Safe to re-enter
  • Protective system adequate
  • Water controlled

Emergency Response​

If Cave-In Occurs:​

DO:

  1. Call 911 immediately
  2. Keep others away from edge
  3. Mark location of victims
  4. Wait for rescue team
  5. Do NOT attempt rescue unless trained

DO NOT:

  • Enter excavation to rescue
  • Dig by hand near victim
  • Allow others in excavation
  • Move heavy equipment near edge

Rescue Considerations:​

  • Secondary collapse risk
  • Professional rescue required
  • Time is critical
  • Document for investigation

Training Requirements​

All Employees Working In/Near Excavations:​

  • Excavation hazards
  • Protective systems
  • Inspection procedures
  • Emergency response
  • Competent person authority

Competent Persons:​

  • Soil classification
  • Protective system selection
  • Inspection techniques
  • OSHA requirements
  • Authority and responsibility

Documentation​

Maintain Records Of:​

  • 811 locate requests and marks
  • Daily inspection logs
  • Soil classification
  • Protective system used
  • Training records
  • Incidents/near-misses
  • JHA Procedure
  • Confined Space Procedure
  • Emergency Action Plan
  • Utility Locate Procedure

Software Integration​

BLDR Pro:

  • Daily excavation inspections
  • Photo documentation
  • Hazard tracking

Safety Meetings App:

  • Excavation toolbox talks
  • Training documentation

OSHA References​

  • 29 CFR 1926.650 (Scope)
  • 29 CFR 1926.651 (Requirements)
  • 29 CFR 1926.652 (Protective Systems)
  • Appendix A (Soil Classification)
  • Appendix B (Sloping and Benching)
  • Appendix C (Timber Shoring)
  • Appendix D (Aluminum Hydraulic Shoring)

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