- Most trenching failure accidents occur between the hours of 8:00 a.m. and noon.
- June, July and August tend to be the months with the highest frequency of severe incidents leading to loss of life during excavation operations; with another spike in October.
- Younger workers between the ages of 26 and 30 are more likely to be involved in critical accidents caused by the collapse of a trench.
- Accidents that involve the collapse of a trench average 3.74 serious violations in an OSHA (Occupational Safety and Health Administration) inspection compared to 2.61 for general construction site inspections.
- The average fine per inspection for a trenching violation is $31, 205, which is nearly four times the average penalty for overall accidents of $7,757.
 With statistics showing increased trenching injuries and fatalities — including statistics from workers compensation claims and death certificates — many states are holding executive managers, company owners and even frontline supervisors and foreman in the field liable for loss of life resulting from failed trench activities. Companies are also being scrutinized, indicted and severely fined for their failure to protect their workers in trenches.
It is essential for contractors and laborers to understand the mandated safety practices and regulations that apply to trenching and excavation operations in the home building process.
Following are OSHA’s top five serious citations for trenching and excavation violations in residential construction:
- Lack of proper protective systems used in the evacuation. There were inadequate or no existing protective systems within the trench or excavation specific to trench sloping, benching, shoring types or trench shield application.
- Lack of site excavation inspections. No company representative/competent person initiated either a “visual” (qualitative: site hazard assessment) or a “manual” (quantitative: classifying the soils) assessment of the excavation when there was clear evidence of distress or warning signs of excavation failure. Common evidences of distresses are:
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Cracks in the soil parallel to or in the face of an excavation
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Subsidence of the edge or bulging of the side of the excavation
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Heaving or boiling of the bottom of the excavation, which is an indication of imminent failure
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Spalling or raveling of the face of the excavation
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Water running into the excavation from the surface, face or bottom of the excavation. Workers cannot be permitted to work in excavations with standing or running water.
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Bending, buckling or groaning of any support members. If any movement of a support member can be seen or heard, an extremely dangerous situation exists.
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Lack of field practices to control the existence of loose rock and soil. There was no protection that consisted of the placement of a spoils pile at a minimum of two feet from the leading edge of the excavation, scaling to remove loose soil material or the existence of interval installation of protective barricades to stop falling soil material.
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Lack of a means of access or egress within the trench. There was no evidence of an existing ladder, ramp or stairway placement within a trench or excavation with a depth equal to or greater than five feet.
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Worker exposure to vehicular traffic. Workers alongside public vehicular traffic and entering an excavation or trench were not provided with high visibility or a reflectorized warning vest.
Following are some recommendations for reducing excavation and trenching accidents in residential construction:
- Affirm or initiate company or contractor safety programs that establish classroom and field performance-based training and education for both workforce members and construction managers in procedures, policies and field practices that apply to excavation work and how to properly document them.
- Enhance work site safety supervision through a “competent person” who can provide “reasonable diligence” practices in the field — such as evaluation of the trench configuration to determine the existence of safety provisions — that recognize and control existing and predictable hazards within or around the trench.
- Strictly enforce and mandate loss-control practices in the field for the proper design and construction of trenches and the placement of support structures. This will allow for workers to work in a safe environment.
It should be noted that several sates operate their own state OSHA programs (click here for a listing), and they may have adopted construction standards for trenching and excavation operations that are different from the information presented here. If you live in a state with its own State Occupational Safety and Health Plan, you should contact your local program administrator for further information on the construction standards applicable in your state.
For more information, e-mail George Middleton, or call him at 800-368-5242 x8590.
Donovan Jackson is a vice president with Integrated Management Services and Construction Practices DIvision within the Willis Risk and Insurance Corporation of Los Angeles. With close to 30 years experience, he specializes in the integration of safety management, quality assurance practices and risk management methodologies into the construction business process, including organizational assurance and development for both field and corporate environments.
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Occupational fatalities and severe injuries such as disfigurement and temporary and permanent body impairment continue to be a main focus of concern in the construction industry. And while data suggest that fatalities from trench wall failure may have decreased in commercial/utility and heavy construction since the 1980s, there is also data indicating that more attention needs to be given to this source of injuries and deaths in single-family and multifamily housing projects in both the land development and construction phases.
