Essential guide: Our Critical Risk expectations
The word MUST means it is a mandatory requirement. Where you see the words YOUR CALL it means you are strongly advised to do this, but you can use your judgement.
In-ground services
When undertaking any excavations, you MUST ensure that all the required notifications and permits have been issued prior to any ground penetrating or excavation works.
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The location of all essential services (underground, adjacent and overhead) MUST be positively identified. Please refer to our Essentials guide for Underground for more detailed information.
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Where possible, any services in close proximity to the excavation MUST be isolated.
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All essential services MUST be protected from mechanical damage.
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Preventing instability
Where relevant, controls to ensure the integrity of adjacent buildings or structures MUST be implemented and maintained.
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You MUST seek the advice of a Geotechnical Engineer wherever there is risk of ground collapse.
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Shoring/benching and battering MUST be installed and implemented as per geotechnical design.
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Regular inspections MUST be conducted to confirm the excavation’s integrity, at a minimum perform a daily inspection before starting work, consideration MUST be given to the risk of the excavation being undertaken.
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Deep excavations
Suitable barriers and warning signs MUST be in place where any person or plant is at risk in the excavation area.
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Safe access/egress into excavations deeper than 1.5m MUST be provided.
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Controls preventing objects from falling on workers in deep excavations MUST be in place. Controls may include, but are not limited to:
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trench box sheets extending beyond the trench depth
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covers or guard rails and toe boards.
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Ingress/contamination
Processes MUST be in place to manage contaminated spoil like asbestos or hydrocarbons. Consideration MUST be given to the prevention of worker exposure.
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The risk of atmospheric contamination in excavations MUST be identified and controlled (including build-up of gases and fumes).
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Possible water sources MUST be identified, and controls are to be implemented.
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A sediment environmental control plan MUST be In place where a risk to the environment has been identified.
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Establishing work zones
Controls preventing the unauthorised access to excavation areas MUST be in place.
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The site conditions and the nature of works MUST be considered when determining the barrier type to be used:
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where an excavation is up to 1m deep, it’s YOUR CALL but consider using bunting/flagging, or barrier mesh
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more suitable barrier types such as water-filled barriers, or 1.8 metre high interlock able hard fencing MUST be used for excavations greater than 1 metre deep
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all barriers MUST have appropriate signage and be at least 1 metre from the edge of the excavation (regardless of depth)
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excavation sites MUST be isolated and made safe when not in use or at the end of each day.
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It’s YOUR CALL but consider the use of a safety observer if the risks associated with the excavation are deemed as high.
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Working near excavations
Excavated soil MUST be placed away from the edge of the excavation so that it does not pose an additional risk.
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You MUST reduce the risk to those working in or near the excavation by limiting access to plant, equipment, and materials directly involved with the work.
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Controls that ensure mobile plant can maintain a safe distance from live services MUST be in place (including overhead power lines).
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Barriers MUST be used in areas adjacent to excavations with frequent mobile plant or pedestrian movement.
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