Excavation work can be dangerous and you must take precautions when excavating a trench, tunnel or shaft.
There are specific laws about doing excavation work safely. Here we summarise those laws and give you some practical tips.
Get information about underground services
Before excavation work begins, you must:
- get information about the location and depth of underground cables, pipes and other essential services
- give the information to those carrying out the work
- make the information readily available for inspection
- keep the information until the work is complete, or for at least two years after a notifiable incident.
More information about underground services and how to locate them is available in the code of practice for construction work.
Manage the risks
You must manage the risks associated with excavation work. The risks include:
- falling into an excavation – eg an excavator tipping into a trench
- being trapped by a collapse
- being struck by falling objects
- being exposed to airborne contaminants
Think about the type of excavation it will be, the options for carrying out the work, and how workers get in and out of the excavation.
Prepare an emergency plan
Your emergency plan must take into account unexpected incidents, such as flooding, gas leaks and rescuing someone from an excavation.
Excavating a trench
If excavating a trench greater than 1.5 metres deep or using mobile plant in or around an excavation, you are generally required to prepare a safe work method statement and prevent unauthorised access (including accidental entry).
You must also ensure all sides of the trench are supported by shoring, benching or battering. Or you must get written advice from a geotechnical engineer that all sides of the trench are safe from collapse.
For the specific laws about doing excavation work safely, see clauses 304 – 306 of the Work Health and Safety Regulation 2011.
There are also general work health and safety laws that will apply to you in any situation, including when doing excavation work.
For general information about planning evacuation work, controlling risks, using different evacuation methods and preventing ground collapse, see the code of practice for excavation work.