TRENCHING & EXCAVATION The OSHA trenching and excavation standards (29 CFR 1926.650, 651, and 652) require employers to evaluate job sites and take appropriate precautions to prevent the occurrence of hazardous conditions during trenching and excavating operations. These standards apply to all open excavations and trenches made in the earth’s surface. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Training of Personnel Employees will be trained on the following: Properly identifying trenches and excavations. Identifying trenching and excavation hazards. Understanding the characteristics of a properly evaluated job site and the hazards of working in or near a trench or excavation. Understanding the qualifications and responsibilities of Competent Persons to evaluate job sites. ENVIRON’s prohibition on entering trenches or excavations deeper than 5 feet. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

What Is a Trench or Excavation ? An excavation is any man-made hole that is formed during the removal of earth. A trench is an excavation that has a width of less than 15 feet and is deeper than it is wide. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Employee Responsibilities All ENVIRON personnel are responsible for reviewing site-specific trenching and/or excavating activities with clients and/or contractors prior to visiting a work site. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Trenching and Excavating Hazards The following hazards may be encountered during trenching and excavation projects: Surface encumbrances Exposure to vehicular traffic Exposure to falling loads, loose rock, or soil Hazardous atmospheres Water accumulation Adjacent structures Falling into the trench or excavation TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Dangers of Collapse The danger of collapse of an exposed face is a main hazard associated with any excavation operation. Collapse may also occur: When the angle of the excavation is too steep for the soil type or environmental conditions present. As a result of heaving - when the weight of surrounding soil pushes against the bottom of a trench. Because of boiling - when water in the bottom of the trench causes soil to become “quick” and lose its weight bearing capability. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Common Atmospheric Hazards A common hazard associated with trenches and excavations is the lack of oxygen or the accumulation of gases such as: Carbon monoxide from powered equipment Hydrogen sulfide (sewer gas) Other heavier than air gases that might displace air TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Properly Evaluated Job Site Employees are responsible for ensuring that: Soil type is evaluated by a Competent Person. Underground utilities are identified. Plans for removing accumulated and/or standing water are in place. Warning lights are in place for night work. Workers are not working under overhead loads. Workers are protected from vehicular traffic and vehicles near the trench and/or excavation. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

What Is A Competent Person? A Competent Person is specially trained to be able to identify existing and predictable hazards or hazardous conditions in the surroundings, or working conditions that are unsanitary, hazardous, or dangerous to employees. A Competent Person has the authority to take corrective actions to eliminate or control trenching or excavation hazards. Only Competent Persons may supervise entry into trenches and/or excavations. This training does not qualify an employee to be considered a Competent Person. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

What a Competent Person Should Know How to identify soil types and problems associated with them Proper use of protective equipment Environmental conditions Operational conditions Recognizing the need for atmospheric testing TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Evaluating the Job Prior to start of work, a Competent Person must inspect the excavation or trench to determine: Evidence of possible cave-ins Indications of failure of protective systems or hazardous atmospheres Stability of adjacent structures Need for proper fall protection TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

How Often Do We Inspect? Trenches and excavations should be inspected on a daily basis for evidence of a situation that could result in possible cave ins, indication of failure of protective systems, hazardous atmospheres, or other hazardous conditions. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

What Should be Inspected? All excavations All trenches Adjacent areas Protective systems Openings (must have safe routes of entry and egress) Atmospheres TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Design of Trenches and Excavations For trenches and excavations greater than 5 feet in depth, shoring, shielding or other protective systems should be in place when the slope of any exposed face is greater than allowed. A registered professional engineer must design the protective system that any excavation greater than 20 feet in depth must have. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Inspection Procedures Daily inspections should be conducted and should include the excavation or trench, adjacent areas, and protective systems. These inspections should be conducted prior to the start of work, as needed throughout the shift, after every rainstorm, and when employee exposure can be reasonably be anticipated. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M

Do Not Enter In general, no ENVIRON employee should enter an excavation or trench deeper than 5 feet. However, if it becomes necessary for an employee to enter, the employee must ensure that the trench or excavation is properly evaluated by a Competent Person prior to entry. TRENCHING & EXCAVATION / E N V I R O N H & S T R A I N I N G P R O G R A M