Work Health and Safety (Excavation Work) Code of Practice 2015

The Work Health and Safety (Excavation Work) Code of Practice 2015 is an approved code of practice made under section 274 of the Work Health and Safety Act 2011. It is a practical guide to achieving the standards of health, safety and welfare required under the WHS Act and the Work Health and Safety Regulations for excavation work.

The Code applies to anyone who has a duty of care in the circumstances it describes. In most cases, following an approved code of practice would achieve compliance with the relevant health and safety duties for the subject matter covered by the code. The Code also makes clear that it does not cover every possible hazard or risk. Duty holders still need to consider all risks associated with the work, not only the ones specifically discussed in the Code.

For businesses, the legal significance is important. Codes of practice are admissible in court proceedings under the WHS Act and Regulations. Courts may treat a code as evidence of what is known about a hazard, risk or control, and may rely on it when deciding what is reasonably practicable. Inspectors may also refer to an approved code of practice when issuing an improvement or prohibition notice.

The Code provides practical guidance for persons conducting a business or undertaking on how to manage health and safety risks associated with excavation work. It applies to all types of excavation work including bulk excavations more than 1.5 metres deep, trenches, shafts and tunnels. The guidance is relevant not only to excavation contractors, but also to businesses that have management or control of workplaces where excavation work is carried out, such as principal contractors.

The Code also identifies several duty holders whose roles matter on an excavation job. A person conducting a business or undertaking has the primary duty to ensure, so far as is reasonably practicable, that workers and other persons are not exposed to health and safety risks arising from the business or undertaking. A principal contractor on a construction project can have additional duties under the WHS Regulations. Designers of structures must ensure, so far as is reasonably practicable, that the structure is without risks to health and safety when used for its designed purpose, and must give the person who commissioned the design a written safety report specifying design-related hazards. Officers, such as company directors, have due diligence duties. Workers must take reasonable care and comply with reasonable instructions, policies and procedures relating to health and safety.

The Code says excavation work generally means work involving the removal of soil or rock from a site to form an open face, hole or cavity using tools, machinery or explosives. That definition is broad enough to catch many common site activities, from service trenching and drainage work to larger civil excavation, shafts and tunnels.

The Code also says a person conducting a business or undertaking must manage risks associated with all kinds of excavations at the workplace, no matter how deep. So a business should not assume that a shallow dig is outside the risk management framework just because it is not a major civil project.

The Code states that specific duties applying to the higher-risk excavations such as trenches, shafts and tunnels do not apply to a mine, a bore to which a relevant water law applies, or a trench used as a place of interment. That is the direct statement in the Code about the boundary of those particular higher-risk excavation requirements.

Businesses should read that carefully. The Code still says a person conducting a business or undertaking must manage risks associated with all kinds of excavations at the workplace, no matter how deep. The exclusion is therefore not a safe assumption that every work health and safety obligation falls away whenever one of those situations is involved. If your work may fall into one of these categories, check the current law and the full Code before relying on the exclusion.

The Code says excavation risks must be managed before the work commences. It specifically refers to the risk of a person falling into an excavation, a person being trapped by collapse, a person working in an excavation being struck by a falling thing, and a person working in an excavation being exposed to an airborne contaminant.

To manage those risks, all relevant matters must be considered, including the nature of the excavation, the nature of the excavation work including the range of possible methods of carrying out the work, and the means of entry into and exit from the excavation if applicable. In practical terms, this means a business should not wait until the excavator is on site or the trench is already open before deciding how the work will be controlled.

Common business trigger points include digging near known or suspected services, opening a trench, working in or near a shaft, using powered mobile plant around an excavation, leaving an excavation open, excavating near buildings or structures, or sending workers into or around the excavation area.

The Code sets out a practical chain of obligations. First, the person conducting a business or undertaking must manage risks to health and safety associated with excavation work. Under the WHS risk management framework referred to in the Code, the duty holder must identify reasonably foreseeable hazards, eliminate the risk so far as is reasonably practicable, or if elimination is not reasonably practicable, minimise the risk so far as is reasonably practicable by implementing control measures in accordance with the hierarchy of control.

The duty holder must also maintain the implemented control measures so they remain effective, and review and, if necessary, revise those control measures so as to maintain, so far as is reasonably practicable, a work environment that is without risks to health and safety.

These are not one-off paperwork duties. They require a business to plan the job, put controls in place, keep them working, and revisit them if conditions change, if the excavation remains open, if weather affects the site, or if the controls are not working as intended.

One of the clearest pre-start duties in the Code concerns underground essential services. The person conducting a business or undertaking who has management or control of a workplace where excavation work is being carried out must take all reasonable steps to obtain current underground essential services information relating to the part of the workplace where the excavation work is being carried out and areas adjacent to it before directing or allowing the excavation to commence.

The Code then says this information must be provided to any person engaged to carry out excavation work. For many businesses, this is a major compliance checkpoint. If the site controller or principal contractor has not obtained current information and passed it on, the excavation process is already exposed before the first cut is made.

The hazards listed by the Code include underground essential services such as gas, water, sewerage, telecommunications, electricity, chemicals and fuel or refrigerant in pipes or lines. It also refers to other underground services such as drainage pipes, soak wells and storage tanks in and adjacent to the workplace.

The Code gives a detailed list of excavation-specific hazards that should be identified. These include underground essential services, the fall or dislodgement of earth or rock, falls from one level to another, falling objects, inappropriate placement of excavated materials, plant or other loads, instability of adjoining structures caused by the excavation, previous disturbance of the ground, instability caused by persons or plant working adjacent to the excavation, the presence of or possible inrush of water or other liquid, hazardous manual tasks, hazardous chemicals in soil, hazardous atmosphere in an excavation, vibration, hazardous noise, and overhead or ground-mounted essential services.

For a business owner, the practical point is that excavation risk is not limited to trench wall collapse. The Code expects a broader site-based assessment of what could go wrong around the excavation, above it, beside it and within it.

The Code says a risk assessment is not mandatory for excavation work in every case, although it is required for some specific situations, such as asbestos. Even where not mandatory, the Code says a risk assessment will often assist in determining the control measures that should be implemented. It can help identify which workers are at risk, what sources and processes are causing the risk, what controls are needed, and whether existing controls are effective.

When assessing risks associated with excavation work, the Code says businesses should consider local site conditions including access, ground slope, adjacent buildings and structures, water courses including underground water, and trees. It also refers to depth of the excavation, soil properties, variable soil types, stability, shear strength, cohesion, the presence of groundwater, the effect of exposure to the elements, fractures or faults in rocks, specialised plant or work methods, transport and haul routes, likely exposures such as noise, ultraviolet rays or hazardous chemicals, the number of people involved, the possibility of unauthorised access, local weather conditions, and the length of time the excavation will be open.

That list shows why a generic excavation SWMS or a standard pre-start form may not be enough on its own. The Code expects the actual site conditions and method of work to be considered.

The Code says you must always aim to eliminate a hazard, because elimination is the most effective control. If elimination is not reasonably practicable, the risk must be minimised by one or a combination of substitution, isolation and engineering controls.

The Code gives practical examples. Substitution may include using an excavator with a rock breaker rather than a manual method. Isolation may include using concrete barriers to separate pedestrians and powered mobile plant to reduce collision risk. Engineering controls may include benching, battering or shoring the sides of the excavation to reduce the risk of ground collapse.

If risk remains, it must be minimised by administrative controls so far as is reasonably practicable, and any remaining risk must be minimised with suitable personal protective equipment such as hard hats, hearing protection and high visibility vests. The Code warns that administrative controls and PPE rely on human behaviour and supervision and, used on their own, tend to be the least effective.

For businesses, the practical message is simple. If the real risk is collapse, falls or plant interaction, stronger physical controls should come first. Signs, inductions and PPE are supporting measures, not the main answer.

The Code structure shows that planning excavation work is not just about digging technique. It covers principal contractors, designers, Safe Work Method Statements, adjacent buildings or structures, essential services, securing the work area and emergency plans. It also includes sections on excavated material and loads near excavations, plant and equipment, powered mobile plant, falls, explosives, atmospheric conditions and ventilation, manual work, information, training, instruction and supervision, excavation methods, and preventing ground collapse.

For a business, that means excavation compliance is partly about documents and partly about conduct. You need the right planning material, but you also need the site to operate consistently with that planning. If the work is high risk construction work, a Safe Work Method Statement must be prepared. If design issues affect safety, the written safety report from the designer matters. If the work area needs to be secured or an emergency plan is required, those steps need to be in place before work starts.

The Code says a person conducting a business or undertaking must consult, so far as is reasonably practicable, with workers who carry out work for them and who are or are likely to be directly affected by a work health and safety matter. If workers are represented by a health and safety representative, the consultation must involve that representative. Consultation is required at every step of the risk management process.

The Code also says duty holders with overlapping duties must consult, co-operate and co-ordinate activities with each other so far as is reasonably practicable. Construction workplaces often involve multiple businesses, such as civil engineers, builders, excavation contractors and service contractors. The Code says persons with overlapping duties should exchange information about excavation risks, including traffic and plant movements near the excavation area, and work together in a co-operative and co-ordinated way so that risks are eliminated or minimised so far as is reasonably practicable.

For shared sites, this means excavation safety cannot be left to one subcontractor in isolation. Site controllers, principal contractors and specialist contractors all need to communicate clearly about who is doing what, what hazards are known, and what controls are in place.

If you run an excavation, plumbing, drainage, civil, landscaping or building business, the safest reading of this Code is that excavation work needs a documented pre-start process and active site control, not just operator experience. The everyday questions are practical. What exactly is being excavated? Who controls the site? Is the work in or near a trench deeper than 1.5 metres, a shaft or a tunnel? Has current underground essential services information been obtained and passed on? What are the entry and exit arrangements? What physical controls are in place for collapse, falls and plant interaction? How will conditions be reviewed if the excavation stays open or weather changes?

If you are the site controller or principal contractor, your exposure is broader than the subcontractor actually digging. The Code places a specific obligation on the person with management or control of the workplace to obtain current underground essential services information before directing or allowing excavation to start and to provide it to the person engaged to carry out the work. If you are an officer, due diligence means making sure the business has and uses appropriate resources and processes to eliminate or minimise excavation risks.

Before relying on this page, businesses should also check the current version of the Code, confirm whether the work falls within any exclusion mentioned in the Code, and consider whether other WHS rules or construction requirements also apply to the project.

Businesses often ask the same practical questions before excavation starts. The safest short answers from the Code are these. The Code is not limited to deep excavations. It applies to all kinds of excavations no matter how deep. A Safe Work Method Statement is required for construction work carried out in or near a shaft or trench deeper than 1.5 metres, or a tunnel. The person with management or control of the workplace must take all reasonable steps to obtain current underground essential services information before directing or allowing excavation to commence, and must provide that information to the person engaged to carry out the work.

The Code also says the specific duties applying to higher-risk excavations such as trenches, shafts and tunnels do not apply to a mine, a bore to which a relevant water law applies, or a trench used as a place of interment. Even so, businesses should check the current law and the full Code before relying on an exclusion or on a different compliance method.

The instrument was approved on 17 December 2015, registered on 30 March 2016 and commenced on the day after registration, being 31 March 2016. The Federal Register listing identifies the instrument as in force.

Before relying on this page for a live project, check the current version on the Federal Register of Legislation and confirm whether any related WHS rules, construction work requirements or project-specific obligations also apply.