Safe Work Procedure: Trench Safety

Document Number: [SWP-NUMBER]
Revision Date: [DATE]
Next Review Date: [NEXT REVIEW DATE]
Department: [DEPARTMENT NAME]

1. Scope

This procedure covers the safe practices for working in and around trenches, including entry, exit, and protection against cave-ins. It applies to all trenching activities on site and is intended to prevent accidents and injuries related to trench work.

This procedure applies to all work environments where trenching is performed, including construction sites and maintenance operations.

Related procedures include the Occupational Health and Safety Regulations and any site-specific safety plans.

2. Definitions

Trench
A narrow excavation made below the surface of the ground, where the depth is greater than the width, but the width is not greater than 15 feet (4.6 m) at the bottom.

Protective System
Methods of protecting employees from cave-ins, including support systems, sloping, benching, and shield systems.

Shoring
A structure that supports the sides of an excavation to prevent cave-ins.

3. Responsibilities

3.1 Supervisors

Ensure all workers are trained in trench safety procedures.
Verify that protective systems are in place and properly maintained.
Conduct regular inspections of trench sites.

3.2 Workers

Follow all safety procedures and use protective equipment as required.
Report any unsafe conditions to supervisors immediately.
Participate in safety training and briefings.

3.3 Health and Safety Representative

Monitor compliance with safety regulations.
Assist in the investigation of incidents related to trench work.

4. Potential Hazards and Risks

Hazard	Risk	Control Measures
Cave-ins	Burial, suffocation	Use of protective systems like shoring or trench boxes [1]
Falling objects	Injury from falling materials	Keep spoil piles at least 1 meter from the trench edge [2]
Hazardous atmospheres	Toxic exposure, asphyxiation	Test for hazardous gases and ensure proper ventilation [2]

5. Personal Protective Equipment (PPE)

Proper PPE is essential for trench safety.

Hard hats - Protect against falling objects.
Safety boots - Provide foot protection from heavy materials.
High-visibility vests - Ensure visibility to machinery operators.
Respirators - Required if hazardous atmospheres are present.
Gloves - Protect hands from sharp objects and materials.

Inspect PPE before use and maintain it according to manufacturer guidelines.

6. Equipment and Tools

Proper equipment and tools are crucial for safe trench operations.

Ladders - Provide safe access and egress from trenches.
Trench boxes - Protect workers from cave-ins.
Shoring systems - Support trench walls to prevent collapse.
Gas detectors - Monitor air quality in trenches.
Pumps - Remove water accumulation from trenches.

Inspect equipment regularly and maintain it according to manufacturer guidelines.

7. Pre-Job Requirements

7.1 Training and Competency

Workers must be trained in trench safety, including the use of protective systems and emergency procedures.

7.2 Pre-Job Briefing

Conduct a briefing to cover the scope of work, potential hazards, and safety measures.

7.3 Work Area Preparation

Ensure the trench area is clear of obstructions and that spoil piles are placed at a safe distance.

8. Safe Work Procedure Steps

Step 1: Site Assessment

Conduct a thorough assessment of the trench site.

Identify potential hazards.
Determine the type of soil and appropriate protective systems.
Ensure all underground utilities are marked [3].

Step 2: Installation of Protective Systems

Install protective systems as required by the depth and soil type.

Use shoring, trench boxes, or sloping as appropriate [1].
Ensure systems are certified by a professional engineer if necessary [4].

Step 3: Safe Entry and Exit

Ensure safe access and egress for workers.

Install ladders or ramps within 8 meters of workers [4].
Ensure ladders extend at least 1 meter above the trench edge [5].

9. Precautions and Safety Measures

Ensure trenches are inspected daily and after any event that could increase hazards.
Do not work under suspended loads or near the edge of the trench.
Keep heavy equipment away from trench edges to prevent collapse.
Use barriers and warning signs to prevent unauthorized access.
Ensure proper ventilation to prevent hazardous atmospheres.

10. Emergency Procedures

10.1 General Emergency Response

In case of an emergency, evacuate the trench immediately and alert emergency services.

10.2 Specific Emergency Scenarios

Cave-in - Evacuate and call emergency services.
Hazardous gas detection - Evacuate and ventilate the area.
Water accumulation - Use pumps to remove water and evacuate if necessary.

10.3 Emergency Contact Information

[List of emergency contacts and their phone numbers]

11. Incident Reporting and Investigation

Report all incidents, near-misses, and hazards to supervisors immediately. Investigate incidents to determine root causes and implement corrective actions.

12. References and Related Documents

Occupational Health and Safety Regulations, 2020 (Sask. Reg. 10/2020)
Occupational Safety General Regulations (N.S. Reg. 44/99)
Canada Occupational Health and Safety Regulations (SOR/86-304)

Approved by: [NAME AND POSITION]
Date: [APPROVAL DATE]