Originally published 07/12/2017
Trench collapses can occur without warning, regardless of the depth. The vast majority of trenching fatalities occur in trenches 5 to 15 feet deep. But trench cave-ins don’t have to happen. They are preventable with proper planning and execution of safety precautions.
Here are some practices that will help reduce the risk of on-the-job injuries or fatalities on excavation sites.
- Know where the underground utilities are located before digging.
- Keep excavated soil (spoils) and other materials at least two feet from trench edges.
- Keep heavy equipment away from trench edges.
- Identify any equipment or activities that could affect trench stability.
- Test for atmospheric hazards such as low oxygen, hazardous fumes, and toxic gases when workers are in trenches more than four feet deep.
- Inspect trenches at the start of each shift. This should be done by the competent person. The competent person should be authorized to order immediate corrective action, including restricting entry into the excavation, until any hazards or potential hazards have been eliminated.
- Ensure that employees working in trenches four feet deep or more have an adequate and safe means of exit, such as ladders, steps or ramps. These must be within 25 feet of all workers at all times and will need to be relocated as the job progresses.
- Inspect trenches following a rainstorm or other water intrusion.
- Inspect trenches after any occurrence that could have changed conditions in the trench.
- Do not work under suspended or raised loads or materials.
- Ensure that workers wear high-visibility or other suitable clothing when exposed to vehicular traffic.
- Develop a trench emergency action plan and train workers and supervisors on the proper actions to take in case of an emergency.
Remember: Unlike most accidents, the cave-in of an excavation can usually be predicted if closely watched. So stay alert. Don’t take anything for granted.