Excavation and trenching are among the most hazardous construction operations. The Occupational Safety and Health Administration’s (OSHA) Excavation standards, 29 Code of Federal Regulations (CFR) Part 1926, Subpart P, contain requirements for excavation and trenching operations. This booklet highlights key elements of the standards and describes safe work practices that can protect workers from cave-ins and other hazards.
A designated competent person who has training in soil analysis, protective systems, and OSHA’s excavation requirements must be on site to classify the soil, select a protective system, oversee installation, and inspect the system after installation.
- If there are no existing hazards the competent person can leave the excavation site for a short time, but must be present when a protective system is moved. Soil conditions
- could change or new hazards may arise that require the competent person’s judgment.
- The competent person must be knowledgeable about the type of soil excavated and the protective system used and must inspect them daily for signs of instability, damage, or other hazards;
- The competent person must approve any changes. Inspections are also necessary after heavy rain or activities such as blasting that may increase the risk of cave-in.
- The competent person must have authority to immediately correct the hazards and to order employees to leave the excavation until the hazards have been corrected.
- An employee who is trained and can identify excavation hazards but doesn’t have the authority to correct them is not a competent person.
Under the Excavation standards, tasks performed by the competent person include:
- Classifying soil;
- Inspecting protective systems;
- Designing structural ramps;
- Monitoring water removal equipment; and
- Conducting site inspections.
Why is preplanning important to excavation work?
No matter how many trenching, shoring, and backfilling jobs an employer has done in the past, it is important to approach each new job with care and preparation. Many on-the-job incidents result from inadequate initial planning. Waiting until after the Occupational Safety and Health Administration 4 work starts to correct mistakes in shoring or sloping slows down the operation, adds to the cost of the project, and makes a cave-in or other excavation failure more likely.
What safety factors should be considered when bidding on a job?
Before preparing a bid, employers should know as much as possible about the jobsite and the materials they will need to have on hand to perform the work safely and in compliance with OSHA standards. A safety checklist may prove helpful when employers are considering new projects.
Factors to consider may include:
- Proximity and physical condition of nearby structures
- Soil classification
- Surface and ground water
- Location of the water table
- Overhead and underground utilities
- Quantity of shoring or protective systems that may be required
- Fall protection needs
- Number of ladders that may be needed
- Other equipment needs.