Underground Services Location and Excavation Procedure

Purpose. This procedure sets out how underground services are identified, located, exposed and protected before and during any excavation, trenching, drilling or ground penetration on a civil or drilling job.

1.Scope

This procedure applies to all excavation, trenching, boring, piling, post driving, drilling and any other ground penetration by Deepridge crews, including on client sites. It applies from the planning stage until backfill is complete.

2.Before the job

The project supervisor must obtain the service plans from the national referral service and the client at least two working days before the job starts and must attach them to the work order. Plans must be treated as indicative only. The supervisor must arrange an electronic locator survey of the work area and mark the surface with the standard colour code.

• Obtain plans from the referral service and the asset owner
• Electronic location by a trained locator
• Surface marking to the standard colour code
• Record the plans and survey on the work order

3.Exposing services

Where a service is within the zone of influence of the excavation, it must be exposed by non-destructive methods, vacuum excavation or hand digging, before any mechanical excavation within the no-go zone. Once exposed, the service must be marked, supported and protected. The exposed location must be recorded on the work order.

4.Mechanical excavation

A spotter must be present for all mechanical excavation within three metres of a known service. The operator must use a smooth-edged bucket in the vicinity of services and must stop immediately on any unexpected contact, change in ground, or smell of gas. High voltage and gas mains require the asset owner's permit and, where required, their attendance.

5.Trench safety

Any trench deeper than 1.5 metres must be benched, battered or shored to the design, and a job hazard analysis and excavation permit must be raised in the Permit to Work and Isolation Register. Nobody may enter a trench that is not supported or that has not been inspected by the supervisor at the start of the shift and after rain.

6.Service strike

If a service is struck, the crew must stop work, move to a safe distance, isolate the area, call the supervisor and the asset owner's emergency line, and record the event in the Hazard and Incident Register as a high potential incident. Nobody may attempt to repair a struck service unless authorised by the asset owner.