Excavation, Trenches, and Earthwork (2019)

The next Steps cover Cal/OSHA safety regulations for Excavation, Trenches, and Earthwork. Where appropriate, we have referenced the code from Title 8 of the California Code of Regulations.

The topics we will cover in this Navitent are:

-Potential Hazards
-Minimum Safety Requirements
-Excavation Requirements
-Protective Systems Requirements
-Safety Orders for Shafts and Wells

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Potential Hazards

Hazards associated with excavation are cave-ins, the striking of underground utilities, falling tools, materials, and equipment, and hazardous air contaminants or oxygen-deficient environments.

Minimum Safety Requirements

The minimum safety requirements for excavation are as follows:

-Before opening an excavation these actions must be taken:
a. Must identify subsurface installations prior to opening an excavation and ensure they are marked.
b. Two working days before starting the work, notify all regional notification centers and all subsurface installations owners who are not members of the notification centers.
Exception: Emergency repair work to subsurface facilities done in response to an emergency, as defined in Government Code section 4216(d).
c. Must receive a positive response from all known owners/operators of subsurface installations.
d. Must meet with owners/operators of high priority (such as high pressure pipelines, natural gas/petroleum pipelines, electrical lines greater than 60,000 volts, etc.) and subsurface installations that are located within 10 feet of the proposed excavation.
e. Only qualified persons (persons that meet training and competency requirements) can perform subsurface installation locating activities.
f. All exposed employees must be trained in excavator notification/excavation activities.
g. Obtain a permit from Division of Occupational Safety and Health (DOSH) if workers are required to enter an excavation that is 5 feet deep or deeper.

-While excavating, the exact locations of the underground utilities must be determined by safe and acceptable means

-Excavators must immediately notify the subsurface installation owner/operator of any damage discovered during or caused by excavating activities. If the damage or escaping material endangers life or property, immediately notify 911

-While the excavation is open, the underground utilities must be protected, supported, or removed as necessary

Excavation Requirements

When employees are in an excavation, the following requirements apply:

-Employees shall be protected from cave-ins by an appropriate protective system
Exception: If excavations are made entirely in stable rock or are less than 5 feet deep, and a competent person has determined that there is no potential for a cave-in, no protective system is needed

-A competent person must be on site to do the following:
a. Conduct inspections of the excavations, adjacent areas, and protective systems before the start of work as needed throughout the shift, and daily for potential cave ins, failures, hazardous atmospheres, or other hazards.
b. Take prompt corrective action or remove employees from the hazard.

-The competent person must be able to demonstrate the following:
a. The ability to recognize all possible hazards associated with excavation work and to test for hazardous atmospheres.
b. Knowledge of the current safety orders pertaining to excavation and trenching.
c. The ability to analyze and classify soils.
d. Knowledge of the design and use of protective systems.
e. The authority and ability to take prompt corrective action when conditions change.

Protective Systems Requirements

Requirements for protective systems include the following:

-Protective system design must be based on soil classification: Stable rock, Type A, B, or C soils. 1541.1 Appendix A (b),(c)

-Soil classification is required as follows unless the protective system design is based on Type C soil:
a. Classification must take into account both site and environmental conditions. 1541.1 Appendix A (a)(1).
b. Soil must be classified by a competent person as Type A, B, or C soil. 1541.1 Appendix A (c)(1).
c. Classification must be based on the results of at least one visual and at least one manual analysis. 1541.1 Appendix A (c)(2) (Note: to view Table and illustration, go to 'Documents' above, pages 56-57 of the Cal/OSHA Pocket Guide for the Construction Industry).

-Standard shoring, sloping, and benching must be used as specified in 1540 and 1541.1(b) or according to tabulated data prepared by a registered engineer (to view, go to 'Documents' above, pages 59-61 of the Cal/OSHA Pocket Guide for the Construction Industry)

-Protective systems for excavations deeper than 20 feet shall be designed by a registered engineer. 1541.1 Appendix F

-Additional bracing must be used when vibration or surcharge loads are a hazard. 1541.1 Appendix A

-Excavations must be inspected as needed after every rainstorm, earthquake, or other hazard-increasing occurrence (water in the excavation may require a reclassification of soil type). 1541(k)(1)

-Employees must be protected from falling materials by scaling, installation of protective barriers, or other methods. 1541(j)(1)

-Uprights shall extend to the top of the trench and its lower end not more than 2 feet from the bottom of the trench. 1541(j)(1)

-Employees must be protected from excavated or other material by keeping such material 2 feet from the excavation edge or by using barrier devices. 1541(j)(2)

-Ladders or other safe access must be provided within 25 feet of a work area in trenches 4 feet or deeper. 1541(c)(2)

-Excavation beneath the level of adjacent foundations, retaining walls, or other structures is prohibited unless requirements of 1541(i) have been met. 1541(i)(1)

-Shored, braced, or underpinned structures must be inspected daily when stability is in danger. 1541(i)(2)

-Walkways or bridges with standard guardrails must be installed when employees or equipment are required or permitted to cross over excavations that are at least 6 feet deep and wider than 30 inches. 1541(l)(1)

-Barriers must be erected around excavations in remote locations. All wells, pits, shafts, and caissons must be covered or barricaded, or if temporary, backfilled when work is completed. 1541(l)(2)

Safety Orders for Shafts and Wells

Safety orders pertaining to shafts and wells include the following:

-All shafts and wells more than 5 feet deep into which workers are required to enter must be retained with lagging, spiling, or casing

-Tests or procedures shall be performed before entry into exploration shafts to ensure the absence of dangerous air contamination or oxygen deficiency

-An employee entering a bell-bottom pier hole or other deep or confined-footing excavation shall wear a harness that has a lifeline attended by another employee

-Shafts in other than hard, compact soil shall be completely lagged and braced

-Head protection is required for workers who enter a well or shaft

-Shafts more than 20 feet deep are subject to the Tunnel Safety Orders (TSOs)

-Provide mechanical exhaust ventilation system and forced air blower or both for shafts 20 feet or less which employees enter and where hazardous atmosphere exists or reasonably expected to exist due to internal combustion engine operation

How much did this Navitent help you to understand the Cal/OSHA safety regulations for Excavation, Trenches, and Earthwork, including:

-Potential Hazards
-Minimum Safety Requirements
-Excavation Requirements
-Protective Systems Requirements
-Safety Orders for Shafts and Wells

Select your response below.

Note: while you don't need to remember all the information in this Navitent, you do need to remember that it is in your Navitent library to refer to when you need it. Go to the Title 8 regulations in the CA Code of Regulations and to the CA Labor Code for detailed information regarding the scope, specifications, and exceptions of a particular regulation and for other requirements that may be applicable to their operations.