Identify the risk
Any kind of trenching has the possibility to pose a hazardous worksite. Because of the instability of the materials being excavated. In addition to the risk of cave ins, workers in trench settings may also be exposed to lethal materials. Drowning is another hazard, water fills the trench before the worker can getaway. Also spill piles and other construction materials must be kept back a safe distance.
Analysis before excavating
Every trenching task is unique, so recognizing the particular risks at the worksite is critical. A qualified worker with specific training in trenching safety must inspect the site. The worksite analysis should also inspect whether there are utility lines or pipelines that may be in close to the dig site. Impact of underground storage reservoirs, overhead power lines near. Traffic on nearby roads might increase causing the adjacent soil to become unstable. The precise location of services must be determined prior to any mechanical excavation. By hand digging or by hydro vac. First call locates are an approximate location, despite their best intentions.
Strategic controls for the risks
OH&S rules state that protective methods must be in place prior to excavation. That involves everything from planning how to handle traffic. Monitoring for gases periodically throughout the day. Providing air circulation and any required respiratory protection as required. A specific worksite may need shoring or trench boxes to safeguard the workers.
Access and Egress
Safe access in and out of the trench is critical. Mainly when a cave in, injury, or other crisis could exist. Workers need to be able to getaway quickly in the event of a cave in. If the trench is 1.5M deep or more, OH&S regulations require proper access and egress for all workers every 8M. That includes ladders, stairs, or a ramp. That egress must be constructed by someone with ground disturbance training. Methods must be protected so that workings of the egress will not be obstructed in the event of an incident.
An excavation worksite is not stationary. Each time a load of dirt is removed or a piece of heavy equipment travels near the excavation, it altars the integrity of the worksite. That is why it’s essential to inspect the worksite at the start of each shift. The worksite must also be inspected after rain falls, or when freezing weather generates slip and fall hazards. Merely having a laborer gaze around is not sufficient. The person who is examining the worksite must have training in ground disturbance. Soil analysis and the correct use of protective systems are also inspected. Excavations 6 meters deep or more need protective systems designed by an authorized engineer.