Site Trenching and Excavation
Site Trenching or Excavation prior to Demolition
More often than not, serious demolitions will involve excavation such as the removal of below grade tanks, slabs, footings, bomb shelters and storm drains. For this reason, SoCal Removal has adopted a policy for the safety of employees performing any excavation, trenching, shoring, sloping and proper safety when working in or around trenches and other excavations. Our policy proudly complies with the following CAL-OSHA regulations or any applicable state or local requirements that are more stringent.
- Specific Excavation Requirements – Title 8-CCR’s
- Requirements for Protective Systems – Title 8-CCR’s
SoCal Removal designates a competent person as the authority for any excavation operations. This person will ensure that all employees are trained in and familiar with required work practices and procedures regarding excavation/trenching operations. The designated competent person and/or other supervisors will make regular inspections of the work site to ensure that all safety measures and systems are in place, correctly installed, and that all safety procedures are followed.
SoCal Removal will implement and enforce the following engineering controls and work practices to prevent employees from being exposed to hazards from existing or ongoing excavations. What is the difference between a trench and an excavation? A trench is a narrow excavation made below the surface of the ground in which the depth is greater than the width – the width not exceeding 15 feet. An excavation is any man-made cut, cavity, trench, or depression in the earth’s surface formed by earth removal. This can include excavations for anything from cellars to highways.
SoCal Removal General Excavation Safety Requirements:
CAL-OSHA requires that workers in trenches and excavations are protected, and that safety and health programs address the variety of hazards they face. The following hazards cause the most trenching and excavation injuries:
- No Protective System
- Failure to Inspect Trench and Protective Systems
- Unsafe Spoil-Pile Placement
- Unsafe Access/Egress
Building Permits and General Contracting
SoCal Removal will comply with permit requirements. For instance, permits may be required for any trenches and excavations five feet or deeper where employee entry is required. Permits may also be required for the erection/dismantling of vertical shoring systems more than three stories or 36 feet high. There are many instances in which a permit may be involved for excavation activities. Regardless of whether a permit is required or not for the digging process to begin, SoCal Removal will always properly slope the excavation properly to eliminate cave-in opportunities.
UTILIZING PROTECTIVE SYSTEMS & EQUIPMENT
All excavations are hazardous because they are inherently unstable. If they are restricted spaces, they present the additional risks of oxygen depletion, toxic fumes, and water accumulation. Protective systems and equipment must be in place in order to avoid injury or loss of life. If you are not using protective systems or equipment while working in trenches or excavations at your site, you are in danger of suffocating, inhaling toxic materials, drowning, being exposed to fire, or being crushed by a cave-in.
SoCal Removal Full Service Contractors – Excavation Safety Protocols: Methods to Avoid Hazards.
Pre-job planning is vital to accident-free excavations; safety measures cannot be improvised as work progresses. A competent person must address the following concerns:
- Evaluate soil conditions and select appropriate protective systems
- Construct protective systems in accordance with the standard requirements
- Preplan; contact utilities (gas, electric) to locate underground lines, plan for traffic control if necessary, and determine proximity to structures that could affect the choice of protective systems
- Test for low oxygen, hazardous fumes, and toxic gases, especially when gasoline engine- driven equipment is running, or the dirt has been contaminated by leaking lines or storage tanks. Insure adequate ventilation or respiratory protection if necessary
- Provide safe access into and out of the excavation
- Provide appropriate protections if water accumulation is a problem
- Inspect the site daily at the start of each shift, following a rainstorm, or after any other hazard-increasing event
- Keep excavations open the minimum amount of time needed to complete operations
INSPECTING TRENCH AND PROTECTIVE SYSTEMS
If trenches and excavations at the site are not inspected daily for evidence of possible cave- ins, hazardous atmospheres, failure of protective systems, or other unsafe conditions, employees are in danger of being exposed to possible serious or fatal injuries.
METHODS TO AVOID HAZARDS Inspect excavations :
- Before construction begins
- Daily before each shift
- As needed throughout the shift
- Following rainstorms or other hazard-increasing events (such as a vehicle or other equipment approaching the edge of an excavation)
- Inspections must be conducted by a competent person who:
- Has training in soil analysis
- Has training in the use of protective systems
- Is knowledgeable about the requirements
- Has authority to immediately eliminate hazards
UNSAFE SPOIL-PILE PLACEMENT
Excavated dirt and materials (spoils) at the site are hazardous if they are set too close to the edge of a trench/excavation. The weight of the spoils can cause a cave-in, or spoils and equipment can roll back on top of workers, causing serious injuries or death.
Temporary spoil must be placed at least 2 feet from the surface edge of the excavation, measured from the nearest base of the spoil to the cut. Do not measure this distance from the crown of the spoil deposit. This distance requirement ensures that loose rock or soil from the temporary spoil will not fall on employees in the trench.
Spoil should be placed so that it channels rainwater and other run-off water away from the excavation. Spoil should be placed so that it cannot accidentally run, slide, or fall back into the excavation.
Permanent spoil should be placed some distance from the excavation. Permanent spoil is often created where underpasses are built or utilities are buried.
The improper placement of permanent spoil, i.e., too close to the working excavation, can cause an excavation to violate the horizontal to vertical ratio requirement for the excavation. This can usually be determined through visual observation. Permanent spoil can change undisturbed soil to disturbed soil and dramatically alter slope requirements.
METHODS TO AVOID HAZARDS
Provide protection by one or more of the following:
- Use retaining devices, such as a trench box, which will extend above the top of the trench to prevent equipment and spoils from falling back into the excavation
- Set spoils and equipment at least 2 feet back from the excavation
- Where the site does not permit a 2-foot setback, spoils may need to be temporarily hauled to another location
SoCal Removal Job Site Protocols for safe Access and Egress:
SoCal Removal will provide safe access and egress to all excavations and demolition operations for any and all jobsites as required by federal and local law. When laborers are in trench excavations, the Standard requires adequate means of entry and exit ladders, steps, ramps, or other safe means of access and egress. Structural ramps used for employee access or egress must be designed by a competent person. If vehicles use the ramps, a competent person qualified in structural design must design them. In addition, structural members used for ramps or runways must be uniform in thickness and joined in a manner to prevent tripping or displacement.
Whether protected by sloping, trench boxes, or shoring, trenches must be provided with ladders so that workers can enter and exit safely. Be informed that, access to and exit from the trench require the following:
- Trenches 4 feet or more in depth should be provided with a fixed means of egress
- Spacing between ladders or other means of egress must be such that a worker will not have to travel more than 25 feet laterally to the nearest means of egress
- Ladders must be placed within the area protected by the shoring or trench box
- Ladders must be secured and extend a minimum of 36 inches above the landing
- Trenches must be regularly inspected for damage
- Metal ladders should be used with caution, particularly when electric utilities are present
- Anyone climbing up or down must always face the ladder and maintain 3-point contact. This means that two hands and one foot or two feet and one hand must be on the ladder at all times. Maintaining 3-point contact means hands must be free for climbing. Tools and materials should not be carried up or down ladders. Pumps, small compactors, and other equipment should be lifted and lowered by methods that prevent injury from overexertion and falling objects.
- An excavation 4 feet or more in depth and occupied by an employee will be provided with either a ladder as a means of access or with a ramp meeting the following requirements:
- A competent person will design structural ramps that are used solely by employees as a means of access or egress from excavations. Structural ramps used for access or egress of equipment will be designed by a competent person qualified in structural design, and will be constructed in accordance with the design
- Ramps and runways constructed of two or more structural members will have the members
- connected together to prevent displacement. Structural members used for ramps and runways will be of uniform thickness
- Cleats or other appropriate means used to connect runway structural members will be attached to the bottom of the runway or will be attached in a manner to prevent tripping
- Structural ramps used in lieu of steps will be provided with cleats or other surface treatments on the top surface to prevent slipping
- An earth ramp may be used in place of a ladder if:
- The ramp material will be stable
- The sides of the excavation above the ramp will be maintained to the maximum allowable slope or sheeted or shored along the means of egress
- The degree of angle of the ramp will not be more than 45 degrees
- Vertical height between the floor of the trench and the toe of the ramp will not exceed 30 inches
- Walkways will be provided where employees or equipment are required or permitted to cross over excavations. Regulation guardrails will be provided where walkways are 6 feet or more above lower levels
- A walkway or sidewalk will be kept clear of excavated material and other obstructions
- The walkways and sidewalks will be lighted if used during hours of darkness
- A walkway or sidewalk that is adjacent to an excavation will be separated from the excavation and protected by an appropriate guardrail