Industrial Safety

Excavation, Trenching, and Shoring Program

V. OPERATIONAL PROCEDURES

A. Permits/Notification

1. The State of California is included in the exception category for government bodies and is not required to complete a Cal/OSHA Construction Activity Permit per CCR Title 8, Section §341(e)(1). This exception does not apply to contractors or outside agencies hired by and working at SDSU doing excavation work. Please see Contractor Responsibilities Section (IV)(E).
   
   
2. A minimum of 2 working days before starting an excavation or any digging underground pipes and utilities must be identified and utility owners must be notified. All Regional Notification Centers in the area involved and all known owners of subsurface facilities in the area who are not members of a Notification Center shall be advised of the proposed work. EXCEPTION: Repair work to subsurface facilities done in response to an emergency.
   
   
3. When necessary plans of as-builts shall be obtained in order to locate underground pipes or utilities.

B. Inspection

1. Daily inspections of excavations, the adjacent areas, and protective systems shall be made by a competent person for evidence of a situation that could result in possible cave-ins, indications of failure of protective systems, hazardous atmospheres, or other hazardous conditions. Inspections shall identify any existing and predictable hazards or working conditions that are hazardous, unsanitary, or dangerous to employees. An inspection shall be conducted by the competent person prior to the start of work and as needed throughout the shift. Since hard packed soil can become unstable after a rain and excavations that are sloped or shored in dry weather can become unstable when it rains, inspections shall also be made after every rain storm or other hazard increasing occurrence. These inspections are only required when employee exposure can be reasonably anticipated.
   
   
2. Where the competent person finds evidence of a situation that could result in a possible cave-in, indications of failure of protective systems, hazardous atmospheres, or other hazardous conditions, exposed employees shall be removed from the hazardous area until the necessary precautions have been taken to ensure their safety.
   
   
3. An Excavation, Trenching, and Shoring Checklist shall be completed by the competent person prior to beginning work. See Attachment A.

C. Encumbrances/Installations

1. All surface encumbrances, i.e. utilities that are located so as to create a hazard to employees shall be removed, supported, or protected from damage as necessary, to safeguard employees.
   
   
2. The approximate location of subsurface installations, such as sewer, telephone, fuel, electric, water lines, or any other subsurface installations that reasonably may be expected to be encountered during excavation work, shall be determined by the excavator prior to opening an excavation.
   
   
3. Excavation shall not commence until:
   1. The excavation area has been marked by the excavator; and
      
      
   2. The excavator has received a positive response from all known owner/operators of subsurface installations within the boundaries of the proposed project; those responses confirm that the owner/operators have located their installations, and those responses either advise the excavator of those locations or advise the excavator that the owner/operator does not operate a subsurface installation that would be affected by the proposed excavation.
      
      
4. When the excavation is proposed within 10 feet of a high priority subsurface installation, the excavator shall be notified by the facility owner/operator of the existence of the high priority subsurface installation before the legal excavation start date and time, and an onsite meeting involving the excavator and the subsurface installation owner/operator’s representative shall be scheduled by the excavator and the owner/operator at a mutually agreed on time to determine the action or activities required to verify the location of such installations. High priority subsurface installations are high pressure natural gas pipelines with normal operating pressures greater than 415 kPA gauge (60 p.s.i.g.), petroleum pipelines, pressurized sewage pipelines, conductors or cables that have a potential to ground of 60,000 volts or more, or hazardous materials pipelines that are potentially hazardous to employees, or the public, if damaged.
   
   
5. Only qualified persons shall perform subsurface installation locating activities. Persons who complete a training program in accordance with the requirements of the California Code of Regulations Title 8, Section §1509, Injury and Illness Prevention Program (IIPP), that meets the minimum training guidelines and practices of the Common Ground Alliance (CGA) Best Practices, Version 3.0, published March 2006, or the standards of the National Utility Locating Contractors Association (NULCA), Standard 101: Professional Competence Standards for Locating Technicians, 2001, First Edition, which are incorporated by reference, shall be deemed qualified.
   
   
6. When excavation or boring operations approach the approximate location of subsurface installations, the exact location of the installations shall be determined by safe and acceptable means that will prevent damage to the subsurface installation, as provided by Government Code Section §4216.4.
   
   
7. While the excavation is open, subsurface installations shall be protected, supported, or removed as necessary to safeguard employees.
   
   
8. An excavator discovering or causing damages to a subsurface installation shall immediately notify the facility owner/operator or contact the Regional Notification Center to obtain subsurface installation operator contact information immediately after which the excavator shall notify the facility operator. All breaks, leaks, nicks, dents, gouges, grooves, or other damages to an installation’s lines, conduits, coatings or cathodic protection shall be reported to the subsurface installation operator. If damage to a high priority subsurface installation results in the escape of any flammable, toxic, or corrosive gas or liquid or endangers life, health or property, the excavator responsible shall immediately follow campus emergency procedures for dialing 911. The facility owner/operator shall also be contacted.
   
   

D. Fall Protection

1. Where employees or equipment are required or permitted to cross over excavations over 6-feet in depth and wider than 30 inches, walkways or bridges with standard guardrails shall be provided.
   
   
2. Adequate barrier physical protection shall be provided at all remotely located excavations. All wells, pits, shafts, etc., shall be barricaded or covered. Upon completion of exploration and other similar operations, temporary wells, pits, shafts, etc., shall be backfilled.

E. Protective Systems

1. Employees shall be protected from cave-ins by an adequate protective system designed in accordance with CCR Title 8 Section §1541.1 (b) or (c) except when excavations are made entirely in stable rock or excavations are less than 5 feet in depth and examination of the ground by a competent person provides no indications of a potential cave in.
   
   
2. If there is the possibility of soil movement as a result of unstable soil based on soil classification, even shallower trenches must be shored.
   
   
3. Excavations in disturbed soil may require additional sheeting or bracing if there is filled ground nearby. For example, a trench wall which is near another previously filled trench is unstable, although it might appear to be hard compact material.
   
   
4. The less stable the soil, the more liquid the soil, the more protection is needed against cave-in.
   
   
5. Protective System Options
   1. Requirements for the design of sloping and benching systems are included in CCR Title 8 Section §1541.1 (b).
      
      
   2. Requirements for the design of support systems, shield systems, and other protective systems are included in CCR Title 8 Section §1541.1 (c).
      
      
6. Protective systems shall have the capacity to resist without failure all loads that are intended or could reasonably be expected to be applied or transmitted to the system.
   
   
7. Trenches 20 feet deep or greater require that the protective system be designed by a registered professional engineer or be based on tabulated data prepared and approved by a registered professional engineer.
   
   
8. Factors for designing a protective system include soil classification, depth of cut, water content of soil, changes due to weather, surcharge load (weight of materials to be used in the trench), and other operations (roadway, vibration) in the area.
   
   
9. In the event of an accident involving the failure of any excavations device or equipment the supervisor or manager shall remove the device or equipment from service until corrective actions are implemented.
   
   
10. Materials and equipment used for protective systems shall be free from damage or defects that might impair their proper function.
    
    
11. Manufactured materials and equipment used for protective systems shall be used and maintained in a manner that is consistent with the recommendation of the manufacturer and in a manner that will prevent employee exposure to hazards.
    
    
12. When material or equipment that is used for protective systems is damaged, a competent person shall examine the material or equipment and evaluate its suitability for continued use. If the competent person cannot assure the material or equipment is able to support the intended loads or is otherwise suitable for safe use, then such material or equipment shall be removed from service, and shall be evaluated and approved by a registered professional engineer before being returned to service.

F. Additional Requirements for Support Systems for Trench Excavations

1. Installation of a support system shall be closely coordinated with the excavation of trenches.
   
   
2. Excavation of material to a level no greater than 2 feet below the bottom of the members of a support system shall be permitted, but only if the system is designed to resist the forces calculated for the full depth of the trench, and there are no indications while the trench is open of a possible loss of soil from behind or below the bottom of the support system.

G. Access and Egress

1. Safe access and egress to all excavations must be provided including but not limited to ladders, steps, and ramps for employees to safely exit while working in trench excavations 4 feet or deeper.
   
   
2. A safe means of egress shall be located so as to require no more than 25 feet of lateral travel for employees.
   
   
3. Structural ramps that are used solely by employees as a means of access or egress from excavations and structural ramps used for access or egress of equipment shall be designed by a competent person qualified in structural design, and shall be constructed in accordance with the design.
   
   
4. Ramps and runways constructed of two or more structural members shall have the structural members connected together to prevent displacement.
   
   
5. Structural members used for ramps and runways shall be of uniform thickness.
   
   
6. Cleats or other appropriate means used to connect runway structural members shall be attached to the bottom of the runway or shall be attached in a manner to prevent tripping.
   
   
7. Structural ramps used in lieu of steps shall be provided with cleats or other surface treatments to the top surface to prevent slipping.
   
   
8. Employees shall not be permitted to work on the faces of sloped or benched excavations at levels above other employees except when employees at the lower levels are adequately protected from the hazard of falling, rolling, or sliding material or equipment.

H. Emergency Rescue

1. The standard campus procedures to follow in the event of a life threatening emergency apply.
   1. A job site employee shall contact Work Control using the radio or other method of communication and Work Control shall contact Public Safety to initiate a rescue response.
      
      
   2. A job site employee can also contact Public Safety directly using a cell phone and dialing 594-1991.
      
      
   3. When communicating the emergency, very specific details shall be provided by the person reporting the incident.
      
      
   4. A job site employee or Work Control shall inform the Supervisor of the incident.
      
      
2. Emergency rescue equipment, such as breathing apparatus, a safety harness and line, or a basket stretcher, shall be readily available where hazardous atmospheric conditions exist or may reasonably be expected to develop during work in an excavation. This equipment shall be attended when in use.
   1. SDSU employees shall not enter excavations where hazardous atmospheric conditions exist or may reasonably be expected to develop during work.
      
      
3. Employees entering bell-bottom pier holes, or other similar deep and confined footing excavations, shall wear a harness with a lifeline securely attached to it. The lifeline shall be separate from any line used to handle materials, and shall be individually attended at all times while the employee wearing the lifeline is in the excavation.

I. Shield Systems

1. Shield systems shall not be subjected to loads exceeding those which the system was designed to withstand.
   
   
2. Shields shall be installed in a manner to restrict lateral or other hazardous movement of the shield in the event of the application of sudden lateral loads.
   
   
3. Employees shall be protected from the hazard of cave-ins when entering or exiting the areas protected by the shields.
   
   
4. Employees shall not be allowed in shields when shields are being installed, removed, or moved vertically.
   
   
5. In trench excavations the sides of the shield shall extend a minimum of 18 inches above the vertical walls of compound excavations. This requirement is described in CCR Title 8 Section §1541.1 Appendix B, Figures B-1, B-1.2, and B-1.3.
   
   
6. On vertically cut trenches the shield shall extend to at least the catch point of the trench.

J. Installation and Removal of Supports

1. Members of support systems shall be securely connected together to prevent sliding, falling, kickouts, or other predictable failure.
   
   
2. Support systems shall be installed and removed in a manner that protects employees from cave-ins, structural collapses, or from being struck by members of the support system.
   
   
3. Individual members of support systems shall not be subjected to loads exceeding those which those members were designed to withstand.
   
   
4. Uprights shall extend to the top of the trench with the lower end of the upright not more than 2 feet from the bottom of the trench.
   
   
5. Before temporary removal of individual members begins, additional precautions shall be taken to ensure the safety of employees, such as installing other structural members to carry the loads imposed on the support system.
   
   
6. Removal shall begin at, and progress from, the bottom of the excavation. Members shall be released slowly so as to note any indication of possible failure of the remaining members of the structure or possible cave-in of the sides of the excavation.
   
   
7. Backfilling shall progress together with the removal of support systems from excavations.

K. Hazardous Atmospheres

1. In addition to the requirements set forth in the Construction Safety Orders and the General Industry Safety Orders to prevent exposure to harmful levels of atmospheric contaminants and to assure acceptable atmospheric conditions, the following requirements shall apply:
   1. Where oxygen deficiency (atmospheres containing less than 19.5 percent oxygen) or a hazardous atmosphere exists or could reasonably be expected to exist, the atmosphere in the excavation shall be tested before employees enter excavations greater than 4 feet in depth.
      
      
   2. Adequate precautions shall be taken to prevent employee exposure to atmospheres containing less than 19.5 percent oxygen and other hazardous atmospheres.
      
      
   3. Adequate precaution shall be taken such as providing ventilation, to prevent employee exposure to an atmosphere containing a concentration of a flammable gas in excess of 20 percent of the lower flammable limit of the gas.
      
      
   4. When controls are used that are intended to reduce the level of atmospheric contaminants to acceptable levels, testing shall be conducted as often as necessary to ensure that the atmosphere remains safe.
      
      
   5. SDSU employees shall not enter excavations where hazardous atmospheric conditions exist or may reasonably be expected to develop during work.

L. Protection from Hazards Associated with Water Accumulation

1. Employees shall not work in excavations in which there is accumulated water, or in excavations in which water is accumulating, unless adequate precautions have been taken to protect employees against the hazards posed by water accumulation. The precautions necessary to protect employees adequately vary with each situation, but could include special support or shield systems to protect from cave-ins, water removal to control the level of accumulating water, or use of a safety harness and lifeline.
   
   
2. If water is controlled or prevented from accumulating by the use of water removal equipment, the water removal equipment and operations shall be monitored by a competent person to ensure proper operation.
   
   
3. If excavation work interrupts the natural drainage of surface water (such as streams), diversion ditches, dikes, or other suitable means shall be used to prevent surface water from entering the excavation and to provide adequate drainage of the area adjacent to the excavation.
   
   
4. Excavations subject to runoff from heavy rains will require an inspection by a competent person and compliance with L1 and L2.

M. Soil Hazards

1. Adequate protection shall be provided to protect employees from loose rock or soil that could pose a hazard by falling or rolling from an excavation face. Such protection shall consist of scaling to remove loose material; installation of protective barricades at intervals as necessary on the face to stop and contain falling material; or other means that provide equivalent protection.
   
   
2. Employees shall be protected from excavated materials that could pose a hazard by falling into excavations. Protection shall be provided by placing and keeping such materials at least 2 feet from the edge of excavations, or by the use of retaining devices that are sufficient to prevent materials from falling into excavations, or by a combination of both if necessary.

N. Adjacent Structures

1. Where the stability of adjoining buildings, walls, or other structures is endangered by excavation operations, support systems such as shoring, bracing, or underpinning shall be provided to ensure the stability of such structures for the protection of employees.
   
   
2. 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 shall not be permitted except when:
   1. A support system, such as underpinning, is provided to ensure the safety of employees and the stability of the structure; or
      
      
   2. The excavation is in stable rock; or
      
      
   3. A registered professional engineer has approved the determination that such excavation work will not pose a hazard to employees.
      
      
3. Sidewalks, pavements and appurtenant structures shall not be undermined unless a support system or another method of protection is provided to protect employees from the possible collapse of such structures.

O. Materials and Equipment

1. Employees shall not be permitted underneath raised loads handled by lifting or digging equipment.
   
   
2. Employees shall be required to stand away from any vehicle being loaded or unloaded to avoid being struck by any spillage or falling materials.
   
   
3. Operators may remain in the cabs of vehicles being loaded or unloaded when the vehicles are equipped with a cab shield and/or canopy to provide adequate protection for the operator from shifting or falling materials during loading and unloading operations.
   
   
4. When mobile equipment is operated adjacent to an excavation, or when such equipment is required to approach the edge of an excavation, and the operator does not have a clear and direct view of the edge of the excavation, a warning system shall be utilized such as barricades, hand or mechanical signals, or stop logs. If possible, the grade should be away from the excavation.
   
   
5. When heavy equipment is being used on an excavation site standard communication procedures established for Physical Plant when using large equipment on the job site shall be followed.
   
   
6. Employees exposed to public vehicular traffic shall be provided with, and shall wear warning vests or other suitable garments marked with or made of reflectorized or high-visibility material.