Excavation collapse (9 June 2022)
A 19-year-old apprentice was seriously injured while clearing a trench on a residential building site. The worker was positioned within a two-metre-high unsupported trench when a section collapsed and engulfed him with soil. The worker sustained multiple fractures and needed to be dug out by other workers on site.
Safety information
Excavation works and working in or near a trench present a serious risk of injury or death. Hazards can include ground collapse, instability of adjoining structures and underground essential services.
You must implement ‘reasonably practicable’ control measures to manage the risks associated with excavation works and working in or near a trench, including to:
- obtain the current underground essential services information (location and depth) relating to the workplace and adjacent areas
- ensure a Safe Work Method Statement (SWMS) is developed and followed for high-risk construction work, such as when the trench depth is more than 1.5 metres, or work is near certain underground essential services
- ensure a competent person, experienced in trenching works, supervises and monitors the work
- ensure the plant is only used for the purpose for which it is designed, is appropriate for the work, maintained in a safe condition and operated by a competent person
- ensure workers not involved with the work and the public cannot access the trench and work areas
- minimise the risk to any person arising from ground collapse on trenches deeper than 1.5 metres by implementing one or more of the following:
- benching – creating a series of steps in the vertical wall of an excavation to reduce the wall height and ensure stability
- battering – sloping the wall of an excavation to a predetermined angle to ensure stability
- shoring – using support systems for an excavated face or faces to prevent the movement of soil and therefore, ground collapse
- obtaining written advice from a geotechnical engineer that all sides of a trench are safe from collapse
- obtain advice from competent persons regarding the soil and groundwater conditions of the site – especially after any event that could affect the safety of the trench (e.g. a weather event or ground slip)
- obtain advice from competent persons regarding any temporary or permanent control measures required to adequately support potentially affected structures, their foundations, and excavated faces
- ensure young workers and apprentices are suitably supervised by a competent and qualified person
- ensure an emergency plan is prepared for the site.
Related information
- Excavation Work – Code of Practice (PDF, 4128.95 KB)
- Construction Work – Code of Practice (PDF, 1014.41 KB)
- How to Manage Work Health and Safety Risks – Code of Practice (PDF, 556.72 KB)
- Construction Safety Information – SafeWork NSW
- The Pocket Guide to Construction Safety – SafeWork NSW (PDF, 1352.71 KB)
- Young workers e-toolkit – SafeWork NSW
- Checklist for training young workers – SafeWork NSW (PDF, 1191.25 KB)
- Traumatic event management plan - SafeWork NSW
- Speak Up Save Lives App – SafeWork NSW
- Mental health at work – NSW Government