Excavation work generally involves removing soil or rock to make a trench, tunnel or shaft, or filling or part filling a trench, tunnel or shaft. It does not include a mine, a bore or a trench to be used as a place of interment.
Risks associated with excavation
There are a range of health and safety risks associated with excavation work including:
- falls from one level to another
- the fall or dislodgement of earth or rock
- vibration and hazardous noise
- exposure to an airborne contaminant.
You should try to eliminate or minimise risks associated with excavation work during the planning stage, before work starts.
- Risk management planning at the start of excavation work is critical to preventing deaths.
During the planning stage you need to identify hazards, assess risks and work out appropriate control measures in consultation with those relevant to the work, for example the principal contractor, demolition contractor, structural engineers and mobile plant operators.
You must also:
- Have regard to all relevant matters including the nature of the excavation, the nature of the work (including the range of possible methods for carrying it out), and the means of entry into and exit from the excavation.
- Take all reasonable steps to obtain current underground essential services information about the part of the workplace where excavation work is being carried out, and any adjacent areas.
- Provide that information to subcontractors and make sure it is available for inspection for at least two years following a notifiable incident, if one occurs, or until the excavation work is complete.
If the excavation work you plan to carry out includes digging a trench at least 1.5 m deep, you must ensure that the work area is secured from unauthorised access, and take all reasonable steps to minimise the risk of the trench collapsing—unless you have written advice from a geotechnical engineer that all sides of the trench are safe from collapse.
- You can get further guidance on managing the health and safety risks associated with excavation work in the model Code of Practice: Excavation Work. The Code applies to all types of excavation work, including bulk excavations more than 1.5 m deep, trenches, shafts and tunnels. Also see Identify, assess and control hazards.
Examples of reducing risk during excavation work
- Substitution—for example use an excavator with a rock breaker rather than doing it manually.
- Isolation—for example use concrete barriers to separate pedestrians and powered mobile plant to reduce the risk of collision.
- Engineering controls—for example benching, battering or shoring the sides of the excavation to reduce the risk of the ground collapsing.
If risk remains you must minimise it by implementing administrative controls, so far as is reasonably practicable.
- For example, install warning signs near the excavation site. Any remaining risk must be minimised with suitable PPE, such as providing workers with hard hats, steel cap boots and high visibility vests.
A licence is required to carry out some excavation work.
- Contact your WHS regulator for more information on excavation licensing. If you’re excavating using powered plant or explosives you may require a licence.
SWA is not a regulator and cannot advise you about excavation work. If you need help, please contact your work health and safety authority.