For those new to worksite trenching and trench safety requirements or for anyone needing a refresher, the United States Department of Labor’s Occupational Health and Safety Administration (OSHA) provides a simple and useful Fact Sheet on Trenching and Excavating Safety. You can always find additional information on OSHA requirements at their website, here.
First and foremost, what’s the difference between excavation and trenching? According to OSHA, excavation is “any man-made cut, cavity, trench, or depression in the earth’s surface formed by earth removal.” Trenching is a specific type of excavation. Again, per OSHA, a trench is an “underground excavated area deeper than it is wide and no wider than 15 feet.”
One of the most critical elements in trench safety is knowing when a trench support system is necessary. OSHA requirements dictate that a protective system is required when trench depth is five feet or greater. The only exception would be if the digging is being done in entirely stable ground. At 20 feet deep or greater, that protective system must be designed or evaluated by a registered professional engineer.
OSHA also requires that a trenched worksite be evaluated daily and when environmental conditions change. This evaluation must be done by a competent person—someone who is capable of identifying and predicting dangerous, unsanitary, or hazardous working conditions and who is also authorized to fix them, ensuring worker safety.
So, what can be done to ensure trench safety? Slope, Shield, or Shore. The type utilized will depend on your unique worksite as well as the other activity in the area, the type of soil, weather conditions, moisture level in the soil, and the depth of the dig. Sloping consists of cutting back the walls of the trench at an angle, away from the excavation. Shoring is the installation of braces to hold back the side walls, and shielding protects workers with a type of box, preventing cave-in of the site. Explore our website for details on your options for bracing solutions.