Job Safety Analysis: Trench Shoring and Excavation Safety

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Step Potential Hazard Control
Assess work area Traffic exposure, unstable soil, overhead lines, pedestrian hazards Conduct full site walk; verify utility locates; establish MUTCD compliant traffic control; designate staging areas
Inspect tools and equipment Damaged ladders, worn shoring, faulty hydraulic components Inspect trench boxes, hydraulic shores, pumps, and ladders; replace defective items immediately
Don required PPE Struck by debris, falling objects, equipment noise Wear hard hat, high visibility vest, gloves, safety glasses, boots, and hearing protection
Perform utility locating and marking Striking gas, electric, sewer, telecom lines Call in locates; hand dig within tolerance zones; maintain constant awareness of markings
Establish excavation limits Cave in hazard, unstable ground Determine trench width and depth; plan spoil pile placement; maintain at least two feet between spoil pile and trench
Begin excavation Equipment striking workers, collapsing banks Only trained operators may excavate; keep workers outside swing radius; excavate using gradual benching if required
Determine soil classification Wrong shoring type, unexpected collapse Identify soil type (A, B, or C); adjust protective system accordingly; treat unknown or saturated soil as worst case
Install shoring or trench box Collapse hazard, struck by shoring components Lower trench box or shoring into trench using equipment; keep workers out until it is secure; use taglines if needed
Provide safe access and egress Falls, ladder failure, trapped workers Place ladders within the trench box; ensure ladders extend above trench edge; maintain three points of contact
Enter trench safely Collapse risk, falling tools Only enter after shoring is verified; keep tools secure; maintain communication with attendant at surface
Perform work inside trench Restricted movement, pinch points, water intrusion Keep work organized; stay inside protective system; monitor for leaks or shifting soil; exit if conditions change
Manage water intrusion Slips, soil weakening, pump hazards Use dewatering pumps; place hoses securely; monitor for soil softening or uplift
Watch for signs of soil movement Cracking, sloughing, vibration related failure Inspect trench frequently; stop work and evacuate if soil shows movement or trench walls shift
Adjust or move shoring as trench progresses Collapse risk, equipment contact Exit trench before moving trench box; reposition with excavator; reenter only once stable
Backfill and compact trench Struck by equipment, unstable footing Keep workers clear during backfill; compact in lifts; maintain communication with equipment operator
Final inspection Remaining hazards, unstable soil, improper restoration Inspect trench area, surface restoration, and utility exposure; confirm the site is safe and stable
Remove traffic control Exposure to live traffic Take down signs and cones in reverse order; wear high visibility PPE; maintain lookout

Suggested Personal Protective Equipment

  • Hard hat

  • Safety glasses or face shield

  • High visibility vest or jacket (Class 3 if roadside)

  • Steel toe boots

  • Cut resistant gloves

  • Long pants and long sleeves

  • Hearing protection near equipment

  • Respirator if working in dusty or contaminated soil environments

Always have a complete, well-stocked first aid kit available.

JSA Category: Water and Sewer Department Operations

* The steps, hazards, and controls displayed above may be incomplete or not suit your department's needs. All job safety analyses should be a completed with frontline worker input to ensure that each potential hazard is identified and mitigated.

Please read about The Essentials Elements of a Solid Job Safety Anaylsis here.

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Job Safety Analysis
Step Potential Hazard Control
Assess work area Traffic exposure, unstable soil, overhead lines, pedestrian hazards Conduct full site walk; verify utility locates; establish MUTCD compliant traffic control; designate staging areas
Inspect tools and equipment Damaged ladders, worn shoring, faulty hydraulic components Inspect trench boxes, hydraulic shores, pumps, and ladders; replace defective items immediately
Don required PPE Struck by debris, falling objects, equipment noise Wear hard hat, high visibility vest, gloves, safety glasses, boots, and hearing protection
Perform utility locating and marking Striking gas, electric, sewer, telecom lines Call in locates; hand dig within tolerance zones; maintain constant awareness of markings
Establish excavation limits Cave in hazard, unstable ground Determine trench width and depth; plan spoil pile placement; maintain at least two feet between spoil pile and trench
Begin excavation Equipment striking workers, collapsing banks Only trained operators may excavate; keep workers outside swing radius; excavate using gradual benching if required
Determine soil classification Wrong shoring type, unexpected collapse Identify soil type (A, B, or C); adjust protective system accordingly; treat unknown or saturated soil as worst case
Install shoring or trench box Collapse hazard, struck by shoring components Lower trench box or shoring into trench using equipment; keep workers out until it is secure; use taglines if needed
Provide safe access and egress Falls, ladder failure, trapped workers Place ladders within the trench box; ensure ladders extend above trench edge; maintain three points of contact
Enter trench safely Collapse risk, falling tools Only enter after shoring is verified; keep tools secure; maintain communication with attendant at surface
Perform work inside trench Restricted movement, pinch points, water intrusion Keep work organized; stay inside protective system; monitor for leaks or shifting soil; exit if conditions change
Manage water intrusion Slips, soil weakening, pump hazards Use dewatering pumps; place hoses securely; monitor for soil softening or uplift
Watch for signs of soil movement Cracking, sloughing, vibration related failure Inspect trench frequently; stop work and evacuate if soil shows movement or trench walls shift
Adjust or move shoring as trench progresses Collapse risk, equipment contact Exit trench before moving trench box; reposition with excavator; reenter only once stable
Backfill and compact trench Struck by equipment, unstable footing Keep workers clear during backfill; compact in lifts; maintain communication with equipment operator
Final inspection Remaining hazards, unstable soil, improper restoration Inspect trench area, surface restoration, and utility exposure; confirm the site is safe and stable
Remove traffic control Exposure to live traffic Take down signs and cones in reverse order; wear high visibility PPE; maintain lookout
Suggested Personal Protective Equipment