Trenching operations are common to many types of construction and maintenance projects and are inherently dangerous. Due to the great exposure, numerous accidents in connection with trenching occur every year. A few simple precautions, if observed, can serve to take most of the risk out of trench construction. Remember, never attempt to make a self rescue by entering a collapsed trench or excavation! There is a high risk that a secondary cave-in can happen!
SAFE WORK PRACTICES FOR TRENCHING AND EXCAVATIONS
- Ensure that the competent person received specific training in, and is knowledgeable about, soil analysis, use of protective systems, and the requirements of 29 CFR 1926 Subpart P: Excavations and Trenches.
- Ensure that the competent person has classified the soil using one manual and one visual test.
- In soils other than solid rock, shale or cemented sand and gravel, the trench should be shored and/or braced, or terraced if over five feet in depth.
- The trench should be shored and braced, regardless of length of time it will be open.
- Ensure that excavations, adjacent areas and protective systems are inspected by a competent person before the start of work, as needed throughout the shift, and after rainstorms or other occurrences that could increase the hazard.
- Place spoils, materials and equipment a minimum of two feet from the edge of the excavation.
- Prohibit employees from walking or working under suspended loads.
- Ensure that utilities companies are contacted and underground utilities are located as required by local, state and federal law.
- Ensure that workers inside an excavation are within 25 feet of a means of access/egress.
- Workers working in trenches should be separated to avoid being struck by fellow workers’ tools: 12-foot spacing is recommended.
- Ensure that ladders used in excavations are secured and extend at least three feet above the edge of the excavation.
- Ensure that employees are protected from cave-ins when entering or exiting from an excavation.
- Ensure that precautions are taken to protect employees from water accumulation.
- Ensure that the atmosphere inside the excavation is tested when there is reasonable possibility of an oxygen deficient, oxygen-enriched, combustible or toxic atmosphere or any other harmful contaminants.
- Ensure employees are trained to use personal protective equipment and other rescue equipment.
- Require workers to wear hard hats in trenches.
- Ensure that materials and equipment used for protective systems are inspected and in good condition.