Workers may also face hazards where the stability of adjacent buildings, walls, or other structures is endangered by excavation operations. Support systems such as shoring, bracing, or underpinning must be provided to ensure the stability of such structures for the protection of employees.
Excavation below the level of the base or footing of any foundation or retaining wall that could be reasonably expected to pose a hazard to employees is not permitted except when the excavation is entirely in stable rock or a support system such as underpinning is provided to ensure employee safety and stability of the structure or a registered professional engineer (PE) has approved the determination that the structure is far enough away excavation activity or that such excavation work will not pose a hazard to employees.
Sidewalks, pavements, and a pertinent structure may not be undermined unless a support system or another method of protection is provided to protect employees from possible collapse. Employees must be protected from loose rock or soil which might create a hazard by falling or rolling from the excavation face.
Materials, and/or machines may become hazardous if measures are not taken to keep them from sliding or falling into an excavation where employees are working. Protection of employees from materials or equipment which could fall or roll into an excavation shall be provided by keeping them at least two feet from the edge of excavations, by the use of adequate retaining devices, or by a combination of both if necessary.
Daily inspections of excavations, the adjacent areas, and protective systems must be made by a competent person for evidence of a situation that could result in possible cave-ins, failure of protective systems, hazardous atmospheres, or other hazardous conditions.
Excavations subject to heavy rain runoff are to be inspected by a competent person and, as necessary, precautions instituted to protect against the hazard. Inspections shall be made after every rainstorm or other hazard-increasing occurrence.
A competent person should make inspections prior to the start of work and as needed throughout the shift as well as after every rainstorm or other hazard increasing occurrence. These inspections are only required when employee exposure can be reasonably anticipated. Where employees or equipment are required or permitted to cross over excavations, walkways or bridges with standard guardrails must be provided.