12 Aug Excavation and Trenching – JSA

Excavation and Trenching Job Safety Analysis (JSA)

Job / Task

Planning, locating utilities, excavating, trenching, installing protective systems, accessing excavations, working within or adjacent to excavations, placing materials, backfilling, and restoring the work area.

Purpose

This Job Safety Analysis (JSA), also known as a Job Hazard Analysis (JHA), identifies hazards associated with excavation and trenching and establishes controls to prevent cave-ins, utility strikes, falls, falling loads, hazardous atmospheres, water accumulation, mobile-equipment incidents, and other excavation-related injuries.

Personnel Qualifications

Excavation and trenching work shall be planned and performed by trained employees under the direction of a competent person as required. The competent person shall be capable of identifying existing and predictable hazards and shall have authorization to take prompt corrective measures.

Personnel involved in excavation and trenching shall:

• Understand the excavation plan, hazards, protective systems, access requirements, and emergency procedures.
• Know the location and status of underground and overhead utilities affecting the work.
• Follow the competent person’s instructions regarding soil conditions and protective systems.
• Remain clear of operating equipment, suspended loads, and unprotected excavation edges.
• Use required access and egress points.
• Report changing soil, water, weather, vibration, utility, or protective-system conditions immediately.
• Never enter an excavation that has not been inspected and determined safe for entry.
• Stop work when an unsafe condition develops.

Required PPE

PPE shall be selected based on the work and site hazards and may include:

• Hard hat.
• Safety glasses with side protection.
• Safety footwear.
• High-visibility apparel.
• Work gloves appropriate to the task.
• Hearing protection where required.
• Respiratory protection when required by an exposure assessment and respiratory-protection program.
• Fall protection where required by the specific exposure and applicable standards.
• Additional task-specific PPE identified by the hazard assessment.

JSA – Job Steps, Hazards, and Controls

Step 1 – Plan the Excavation

Potential Hazards

• Cave-in.
• Utility strike.
• Equipment collision.
• Inadequate protective system.

Required Controls

• Review the scope, excavation dimensions, soil and site conditions, nearby structures, traffic, equipment, and expected duration.
• Identify the competent person responsible for excavation inspections and protective-system decisions.
• Determine anticipated protective systems, access/egress, spoil placement, equipment locations, and emergency arrangements.
• Identify overhead and underground utility hazards before work begins.
• Coordinate excavation activities with affected employees, subcontractors, and site representatives.

Step 2 – Locate Underground Utilities

Potential Hazards

• Electrocution.
• Fire or explosion.
• Flooding.
• Utility interruption.

Required Controls

• Contact the appropriate utility-locating service and facility owner as required before excavation.
• Review available drawings, markings, records, and site information.
• Clearly mark known utility locations and communicate them to equipment operators and workers.
• Use safe exposure methods when approaching the estimated location of underground installations.
• Stop work when utility markings are missing, unclear, or inconsistent with actual conditions.

Step 3 – Evaluate Surface Encumbrances

Potential Hazards

• Falling objects.
• Structural collapse.
• Equipment interference.

Required Controls

• Identify trees, poles, signs, structures, pavement, stored materials, and other surface encumbrances that may create hazards.
• Remove, support, or otherwise control hazardous encumbrances before excavation.
• Evaluate adjacent structures that could be affected by excavation.
• Use support systems where excavation could endanger nearby foundations, walls, sidewalks, or other structures.
• Maintain required clearances from overhead hazards.

Step 4 – Establish the Work Zone

Potential Hazards

• Pedestrian fall.
• Vehicle intrusion.
• Struck-by injury.

Required Controls

• Barricade or otherwise identify the excavation work area.
• Establish equipment routes and pedestrian pathways.
• Provide traffic control where work affects roads, parking areas, or vehicle routes.
• Keep unauthorized personnel away from excavation edges and equipment operating zones.
• Provide adequate lighting when natural illumination is insufficient.

Step 5 – Perform the Initial Competent-Person Inspection

Potential Hazards

• Cave-in.
• Protective-system failure.
• Unrecognized hazardous condition.

Required Controls

• Inspect the excavation area, adjacent ground, protective systems, utilities, water conditions, and nearby operations before employees enter.
• Classify soil as required for selection of protective systems.
• Identify signs of tension cracks, fissures, sloughing, bulging, settlement, vibration, or previously disturbed soil.
• Determine whether hazardous atmosphere testing is required.
• Do not permit entry until identified hazards are controlled.

Step 6 – Begin Mechanical Excavation

Potential Hazards

• Utility strike.
• Struck-by.
• Equipment rollover.
• Falling material.

Required Controls

• Keep employees clear of the excavator or backhoe swing radius and digging area.
• Use a spotter when visibility is restricted or when working near utilities or other hazards.
• Maintain equipment on stable ground and a safe distance from excavation edges.
• Excavate carefully when approaching marked underground installations.
• Stop immediately if an unknown line, structure, unusual material, or unsafe condition is encountered.

Step 7 – Expose Underground Utilities

Potential Hazards

• Electrical contact.
• Gas release.
• Utility damage.

Required Controls

• Determine the exact location of underground installations by safe and acceptable means as excavation approaches them.
• Use hand digging, vacuum excavation, or other approved methods where required.
• Support exposed utilities when necessary to prevent damage.
• Protect employees from contact with energized or pressurized utilities.
• Stop work and follow emergency procedures if a utility is damaged or contacted.

Step 8 – Place Spoil and Materials

Potential Hazards

• Material falling into excavation.
• Excess surcharge load.
• Edge collapse.

Required Controls

• Keep excavated material and equipment at least 2 feet from the excavation edge unless an effective retaining device or other protective measure is used.
• Place spoil so it cannot roll, slide, or fall into the excavation.
• Do not overload unstable or unsupported ground near the edge.
• Maintain access routes and emergency egress points.
• Control dust and loose material as needed.

Step 9 – Select and Install the Protective System

Potential Hazards

• Cave-in.
• Crushing.
• Protective-system failure.

Required Controls

• Use sloping, benching, shoring, shielding, or another acceptable protective system when required.
• Select the system based on excavation depth, soil classification, water, surcharge loads, adjacent structures, and other conditions.
• Install protective systems in accordance with applicable OSHA requirements, tabulated data, or approved engineering designs.
• Do not exceed the limitations of trench boxes, shoring systems, or manufactured protective systems.
• Keep employees out of unprotected areas during installation or removal.

Step 10 – Install Trench Boxes / Shields

Potential Hazards

• Crushing.
• Caught-between injury.
• Cave-in during installation.

Required Controls

• Use equipment capable of safely handling the shield or trench box.
• Keep employees clear of suspended or moving trench boxes.
• Follow manufacturer requirements for spreaders, pins, stacking, and configuration.
• Prevent employees from being inside a shield while it is being installed, removed, or vertically moved unless the procedure and equipment are specifically designed and permitted for that operation.
• Excavate no deeper below the bottom of the shield than allowed by applicable requirements and only when soil conditions are safe.

Step 11 – Provide Safe Access and Egress

Potential Hazards

• Fall.
• Delayed escape.
• Climbing on unsafe surfaces.

Required Controls

• Provide a stairway, ladder, ramp, or other safe means of egress in trench excavations 4 feet or more in depth.
• Locate access so employees do not travel more than 25 feet laterally to reach it.
• Secure ladders and extend them sufficiently above the landing surface for safe access where applicable.
• Keep access points clear of equipment, spoil, mud, and materials.
• Do not climb on shoring, trench boxes, utility lines, or excavation faces.

Step 12 – Enter the Excavation

Potential Hazards

• Cave-in.
• Fall.
• Falling material.
• Hazardous atmosphere.

Required Controls

• Enter only after the competent person has inspected the excavation and authorized entry.
• Use designated access and egress.
• Remain within the protected area when a protective system is required.
• Do not enter areas where water, soil movement, damaged protective systems, or other uncontrolled hazards exist.
• Maintain communication with personnel outside the excavation as appropriate.

Step 13 – Work Inside the Excavation

Potential Hazards

• Cave-in.
• Struck-by.
• Caught-between.
• Falling objects.

Required Controls

• Remain alert for changing soil conditions, cracking, sloughing, bulging, water seepage, or movement of protective systems.
• Keep employees clear of equipment operating directly above or adjacent to the excavation.
• Do not work beneath suspended loads or loads handled by lifting or digging equipment.
• Keep tools and materials organized to preserve safe access.
• Stop work and exit immediately when conditions become unsafe.

Step 14 – Work Near Mobile Equipment

Potential Hazards

• Run-over.
• Equipment falling into excavation.
• Caught-between injury.

Required Controls

• Separate pedestrian work areas from equipment travel routes where practical.
• Use barricades, warning systems, or spotters when equipment approaches an excavation and the operator does not have a clear view of the edge.
• Maintain safe equipment setback from excavation edges.
• Keep employees out of equipment blind spots and swing radii.
• Use high-visibility apparel where employees are exposed to vehicle traffic.

Step 15 – Protect Employees from Falling Loads

Potential Hazards

• Crushing.
• Struck-by injury.

Required Controls

• Do not permit employees beneath loads handled by lifting or digging equipment.
• Keep employees away from vehicles being loaded or unloaded where falling material could strike them.
• Use controlled loading and material-handling procedures.
• Keep buckets and suspended materials away from occupied excavation areas.
• Use tag lines or other controls where appropriate and safe.

Step 16 – Control Water Accumulation

Potential Hazards

• Cave-in.
• Drowning.
• Slip hazard.
• Protective-system failure.

Required Controls

• Do not allow employees to work in excavations with accumulated or accumulating water unless adequate protective measures are implemented.
• Use pumps, drainage, diversion ditches, or other controls as appropriate.
• Monitor water-control equipment and conditions.
• Have the competent person inspect excavations affected by heavy rain or changing water conditions before reentry.
• Protect drainage systems and adjacent ground from erosion that could undermine the excavation.

Step 17 – Control Hazardous Atmospheres

Potential Hazards

• Oxygen deficiency.
• Toxic exposure.
• Fire or explosion.

Required Controls

• Test the atmosphere before employees enter excavations 4 feet or more in depth where a hazardous atmosphere exists or could reasonably be expected.
• Test for oxygen deficiency and hazardous gases or vapors as appropriate.
• Provide ventilation or other controls when hazardous atmospheres are detected.
• Use respiratory protection only in accordance with an established respiratory-protection program.
• Provide emergency rescue equipment when required by the atmospheric hazard.

Step 18 – Work Near Roads or Public Areas

Potential Hazards

• Vehicle intrusion.
• Public fall exposure.
• Struck-by injury.

Required Controls

• Implement the required traffic-control plan.
• Use signs, cones, barricades, barriers, flaggers, or other controls as appropriate.
• Protect pedestrians from open excavations and redirect them to safe routes.
• Maintain visibility of excavation barriers during darkness or poor weather.
• Coordinate construction traffic entering and leaving the work zone.

Step 19 – Cross an Excavation

Potential Hazards

• Fall into excavation.
• Collapse of improvised crossing.

Required Controls

• Use only designated walkways or bridges when employees or equipment must cross an excavation.
• Ensure crossings are designed for the intended load.
• Provide guardrails where required for employee walkways.
• Do not use loose planks, pipes, buckets, trench-box spreaders, or improvised crossings.
• Keep crossings clear of mud, debris, and materials.

Step 20 – Work Near Overhead Power Lines

Potential Hazards

• Electrocution.
• Electrical arcing.

Required Controls

• Identify overhead electrical lines before operating excavating, lifting, or material-handling equipment.
• Maintain applicable minimum approach distances.
• Use a spotter where necessary to maintain clearance.
• Treat lines as energized unless confirmed de-energized and properly controlled by the responsible utility or authorized party.
• Consider the maximum reach and height of equipment and loads.

Step 21 – Inspect After Changing Conditions

Potential Hazards

• Cave-in.
• Protective-system failure.

Required Controls

• The competent person shall inspect excavations daily before work and as needed throughout the shift.
• Conduct additional inspections after rainstorms, water intrusion, vibration, soil movement, protective-system damage, or other hazard-increasing events.
• Remove employees from hazardous areas until corrective action is completed.
• Reevaluate soil and protective-system conditions when circumstances change.
• Document inspections when required by company or site procedures.

Step 22 – Modify or Remove Protective Systems

Potential Hazards

• Cave-in.
• Crushing.
• Unexpected soil movement.

Required Controls

• Modify protective systems only under competent-person direction and within approved design limitations.
• Keep employees clear of areas exposed during removal.
• Remove support systems from the bottom upward where appropriate and release members slowly to detect possible failure.
• Backfill progressively with removal when conditions require.
• Do not remove protective systems while employees remain exposed to cave-in hazards.

Step 23 – Backfill the Excavation

Potential Hazards

• Utility damage.
• Struck-by.
• Equipment rollover.

Required Controls

• Confirm employees and unnecessary materials are removed from the excavation.
• Protect utilities, structures, and remaining installations during backfill.
• Use controlled equipment movements and keep personnel outside operating zones.
• Place backfill in a manner that does not destabilize adjacent structures or protective systems.
• Maintain safe equipment setback until the excavation is adequately filled and compacted.

Step 24 – Restore the Work Area

Potential Hazards

• Trip hazard.
• Traffic hazard.
• Residual opening or unstable ground.

Required Controls

• Remove unused materials, barricades, and equipment only when no longer required.
• Restore walking and driving surfaces as required.
• Secure or protect any excavation that remains open.
• Verify utilities, covers, pavement, and site features are left in a safe condition.
• Communicate remaining hazards to affected personnel.

General Safe Work Requirements

• A competent person shall inspect excavations, adjacent areas, and protective systems before employees enter, daily before work, and as conditions warrant.
• Employees shall be protected from cave-ins by an adequate protective system except where an applicable OSHA exception permits otherwise.
• Protective systems shall be selected and installed according to soil conditions, excavation depth, surcharge loads, water, adjacent structures, and applicable design requirements.
• Underground installations shall be located before excavation, and their exact locations shall be determined by safe means as work approaches them.
• Spoil piles, materials, and equipment shall be kept at least 2 feet from excavation edges unless adequately retained or otherwise controlled.
• Safe access and egress shall be provided in trench excavations 4 feet or more in depth so employees travel no more than 25 feet laterally to reach it.
• Employees shall not work beneath suspended loads or loads handled by lifting or digging equipment.
• Employees shall be protected from loose rock, soil, materials, and equipment that could fall or roll into the excavation.
• Warning systems shall be used when mobile equipment approaches excavation edges and the operator does not have a clear view of the edge.
• Accumulated or accumulating water shall be controlled before employees work in affected excavations.
• Atmospheric testing shall be performed where hazardous atmospheres exist or could reasonably be expected.
• Protective measures shall be provided for excavations affected by traffic, pedestrians, overhead power lines, adjacent structures, or other site hazards.
• Employees shall exit immediately when the competent person identifies evidence of a possible cave-in, protective-system failure, hazardous atmosphere, water hazard, or other dangerous condition.
• Protective systems shall not be modified outside their approved design or manufacturer limitations.
• Work shall stop whenever utility information, protective systems, access, ground conditions, atmospheric controls, or other required safeguards are inadequate.

Training

Employees involved in excavation and trenching shall receive training appropriate to their assigned duties. Training shall address cave-in hazards, competent-person authority, soil and protective-system awareness, underground and overhead utilities, access and egress, spoil placement, mobile-equipment hazards, falling loads, water accumulation, hazardous atmospheres, traffic and pedestrian controls, emergency procedures, and the requirement to immediately leave an excavation when unsafe conditions develop. Operators, competent persons, and employees installing protective systems shall receive additional training appropriate to their responsibilities.

References

• OSHA 29 CFR 1926 Subpart P – Excavations.
• OSHA 29 CFR 1926.650 – Scope, Application, and Definitions.
• OSHA 29 CFR 1926.651 – Specific Excavation Requirements.
• OSHA 29 CFR 1926.652 – Requirements for Protective Systems.
• OSHA 29 CFR 1926 Subpart P, Appendices A-F, as applicable.
• Applicable utility-location requirements, protective-system tabulated data, manufacturer instructions, site procedures, and client requirements.