October 25

Excavation and Trenching Safety Guidelines

We normally have posts on specific topics pertaining to the select industries we serve, in this case, Land Improvement and Site Preparation contractors via our SitePro program. However, in this iteration we’d like to share with our broker readers a list of guidelines that serve as an extremely efficient mitigation of risk and exposure during excavations.

  • Establish the locations of underground and overhead utilities and services before beginning excavation. Contact utility companies and municipally-owned utilities and advise them prior to the start of actual excavation.
  • Make an inspection after every rainfall or other hazard-producing occurrence, if you are the competent person.
  • Do not allow water to accumulate in excavations.
  • Use heavier sheet piling, shoring or bracing with superimposed loads, such as cranes working close to excavation edges. Using mobile equipment near excavations also requires extensive barricades or stop logs.
  • Make sure employees working in trenches 4 feet deep or more have an adequate and safe means of exit, such as ladders, steps or ramps available at no more than 25 feet of lateral travel. In excavations more than 20 feet deep, equip ladders with ladder platforms at 20 foot intervals.
  • Make sure a competent person capable of identifying existing and predictable hazards, and with the authority to take prompt corrective action to eliminate them is on the site. The person should be able to identify soil classifications and the protective systems to use in accordance with the OSHA trenching standard.
  • Ensure that trenches more than 5 feet deep have shoring or are laid back to a stable slope. In unstable soil, you must protect trenches less than 5 feet deep.
  • Design, construct and maintain portable trench boxes or sliding trench shields used in place of shoring and sloping to provide protection at least equal to the required sheeting and shoring. Ensure a registered professional engineer designs the shields.
  • Install shields to restrict lateral or other hazardous movement.
  • Make sure trench boxes and shields extend to the bottom of the trench and no less than 6 inches above the vertical part of the trench face, except in certain cases (see OSHA 1926.652).
  • Do not allow employees in shields during their installation, removal or relocation.
  • Provide a means of attaching trench boxes when they are stacked to prevent them from separating.
  • Do not work outside of trench shields or shoring protection in unprotected trenches.
  • Do not ride buckets to enter or leave a trench.
  • Avoid jumping into or across trenches.
  • Place trench jacks or cross braces in true horizontal position, spaced vertically and secured to prevent sliding, falling or kick outs.
  • Use ropes to pull out jacks or braces after employees have vacated the trench.
  • Perform backfilling and trench support removal together from the bottom of the trench. Release jacks and supports slowly.
  • Make sure qualified personnel design and install piling, sheeting, shoring, shields and support systems. Ensure the shoring system can withstand all loads imposed upon it.
  • Ensure that material and equipment used for sheeting, sheet piling, bracing, shoring and underpinning are in good serviceable condition. Use timbers that are sound and free of defects.
  • Store spoil at least 2 feet away from where employees enter excavations, or use effective retaining devices.
  • Install additional underpinning shoring or bracing when required in cases where adjoining utility lines, foundations, walks and footings are endangered.
  • Extend vertical supports in the bracing system to an elevation no less than one foot above
    the top of the trench face.
  • Erect standard guard railing or solid sheeting no less than 42 inches above ground level around all tunnel shafts and bore pits.
  • Protect employees in bell-bottom pier holes by removable type steel casings and individually- manned lifelines and harnesses. Follow confined-space entry procedures.
  • Protect each employee from falling by using guardrail systems, fences, barricades or covers at the edge of a well, pit, shaft and similar excavation 6 feet or more in depth.
  • Install standard guardrail systems along ramps, runways or bridges over excavations that are more than 6 feet deep.
  • Backfill trenches as the work progresses.


For more information on excavation insurance and risk management, visit SitePro.

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