Trenching and Excavation Safety

Despite the readily available information on trenching and excavation safety, 2016 trench-related fatalities were reported to be a shocking 12 deaths higher than the two previous years, totaling 23 fatalities. Trenching and excavation are classified by OSHA as among “the most hazardous construction operations,” so it’s important that employers take the necessary precautions to protect their workers from preventable injuries or deaths.
 
The Importance of Preplanning
Prevent trenching and excavation accidents by adequately planning for your projects. Take proactive measures to ensure that you have the necessary materials and equipment for the job. Other important factors are:

• Soil classification
• Surface and groundwater
• Location of water table

After doing the necessary research to determine the equipment needed for job safety, OSHA requires you to locate all sewer, telephone, fuel, electric and water lines. One industry-standard practice is to call 811, the “Call Before You Dig” number, which will provide you with the location of any underground utility installations. Be sure to notify utility companies or nearby property owners of the nature of your work. You can further safeguard your workers by protecting, supporting or removing underground utilities while the excavation is open.

Trenches and Excavation Dangers
An excavation is defined as “any man-made cut, cavity, trench or depression in Earth’s surface formed by earth removal.” A trench is a narrow excavation that is no deeper than 15 feet.

Employers should be aware of cave-ins, as they pose the greatest risk to workers and are the most likely excavation-related hazard to occur. One cubic yard of soil can weigh over 3,000 pounds, making surviving a cave-in nearly impossible. According to OSHA standards, any trench or excavation that is deeper than five feet must be fitted with a protective system to prevent cave-ins. Trenches and excavations less than five feet may not need a protective system if they are inspected and cleared by a competent person. A protective system for any trench deeper than 20 feet must be designed or approved by a registered engineer in order to comply with OSHA standards.

Basic protective systems include:

• Sloping and benching the sides of the excavation
• Supporting the sides of the excavation
• Placing a shield between the side of the excavation and the work area

Be aware of other trench and excavation hazards, such as falling debris, toxic atmospheres and hazards involving mobile equipment. OSHA warns all workers to not enter an unprotected trench: “an unprotected trench is an early grave.”

General Protective Tactics
Other than ensuring all trenches are appropriately fitted with protective systems, employers are responsible for following OSHA’s general trenching and excavation rules. You are expected to inspect trenches at the start of each shift for any changes in stability, especially after experiencing hazardous weather conditions. You are also required to keep heavy machinery and excavated soil at least two feet away from trench edges, and verify that all workers are wearing and using the proper safety gear and equipment. Failure to implement any of these safety strategies will, in the best case scenario, result in fines or, worst case scenario, fatalities.

It is your responsibility to educate and inform your employees on proper trench and excavation safety requirements and procedures. Click to here to learn more about employer responsibilities.

Infographic: Protect Workers in Trenches