Excavation & Trenching Procedure

Procedure Excavation and Trenching

QCOPS-BX00-HSS-PCE-000007

Rev 0

May 2012

Uncontrolled when printed

Upstream Operations

Upstream Operations Excavation Procedure

QCOPS-BX00-HSS-PCE-000007 Revision 0 May 2012

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Table of Contents

1.0 FOREWARD 5

1.1 Scope of Document 5

1.2 Document Revisions and Approval 5

1.3 Distribution and Intended Audience 5

2.0 RESPONSIBILITIES 5

3.0 RISK MANAGMENT 9

3.1 Hazard Identification 9

3.2 Risk Assessment (Safe Work Method Statement) 10

3.3 Risk Control 11

4.0 DESIGN 11

5.0 PLANNING 11

5.1 Survey of Area to be Excavated 12

5.2 Adjacent Buildings or Structures 12

5.3 Location of Underground Pipes and Cables 12

5.4 Excavation to Expose Existing Pipes or Cables 13

5.5 Excavation Around Live Underground Services 13

5.6 Excavation underneath electrical hazards or overhead obstructions 13

5.7 Selection and Transport of Excavation Equipment 14

5.8 Working Room and Working Alone 14

5.9 Work at Night/ Lighting 14

5.10 Backfilling 15

6.0 PERMIT TO WORK (PTW) FOR EXCAVATION 15

7.0 EMERGENCY AND RESCUE PROCEDURES 15

8.0 PPE AND SAFETY EQUIPMENT 16

9.0 INSPECTIONS OF EXCAVATIONS 16

10.0 MANAGING EXCAVATION WORKS 17

10.1 Excavation Register 17

10.2 Access and Egress 17

10.3 Limits of Approach 18

10.4 Service Identification 18

10.5 Colour Codes for Service Identification 18

10.6 Temporary services 18

10.7 Excavation Depth Criteria 18

10.7.1 Depth less than 1.2 metres 18 10.7.2 Depth 1.2 metres or greater 19



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10.8 Narrow Trenches, Ditches and Small Holes 19

10.9 Shoring and Ground Support 19

10.10 Benching and battering 20

10.11 Fall prevention 20

10.12 Barriers, barricades and signage 21

10.12.1 Public access 21 10.12.2 Work Near Roads or Footpaths 21 10.12.3 Specific requirements 22

10.13 Movement of Vehicles and Plant Near, or Over, Excavations 22

10.14 Confined Spaces 22

10.15 Hazardous Substances 22

10.16 Site contamination 23

10.16.1 Equipment oil/fuel spill response 23 10.16.2 Acid sulphate soils 23

10.17 Underground services (DIAL BEFORE YOU DIG) 24

10.18 Excavation Material 24

10.19 Ventilation, Harmful Gases and Fumes 25

11.0 ENVIRONMENTAL AND COMMUNITY ISSUES 25

11.1 Community consultation- Impact on surrounding community 25

11.2 Noise 25

11.3 Water management 25

11.4 Water logged ground. 25

11.5 Erosion from adverse weather 26

11.6 Plant wash down (seed transfer) for excavation equipment and transport. 26

11.7 Cultural, environmental or archaeological issues 26

12.0 COMPLETION OF EXCAVATION WORKS 26

13.0 TRAINING AND QUALIFICATION 27

13.1 Supervision 27

13.1.1 Mobile plant operators 28

14.0 AUDIT AND MANAGEMENT REVIEW 28

Appendices Table of Contents

APPENDIX A – Document Distribution Rrecord (RACIE Sheet) 29

APPENDIX B – Definitions and References 31

APPENDIX C – Certificate 37

APPENDIX D – Feedback Form 38



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1.0 FOREWARD 1.1 Scope of Document

The purpose of the QGC Excavation procedure is to assist all personnel working on all QGC Operations and Projects’ sites to carry out work in accordance with safe working practices for excavation and ground penetrations.

The Excavation procedure has been developed to ensure compliance with applicable BG Standards and is to be used in conjunction with all applicable legislation, including Codes of Practice, and relevant Australian Standards.

The document applies to all QGC personnel and contracting staff working on sites under QGC Upstream Operations or Project control and will follow the principles established in the QGC PTW Procedure (QCOPS-BX00-HSS-PCE-000002).

The QGC Excavation and Digging procedure applies to all Operational sites (Brownfield sites) and to all Upstream Project sites. Greenfield sites are designated through the Greenfield Construction Assessment Process and a formal handover of Greenfield designated real-estate is undertaken before any Greenfield construction work can commence.

Note: Where there are differences in process for Greenfield sites, these are clearly identified in Greenfield text boxes.

This procedure addresses the HSE aspects of ground penetrations, open excavation, trenching and shoring operations on QGC .

This document defines the responsibilities of nominated persons and approvals required for the excavation.

Local legislation may detail additional requirements and workplaces must include any further detail when considering the application of this procedure relevant to the workplace risk assessments.

1.2 Document Revisions and Approval

This document bears a revision status identifier which will change with each revision. All revisions to this document (after approval and distribution) are subject to review and endorsement by the same functions as the original.

1.3 Distribution and Intended Audience

This document is intended for Operations members as well as other QGC stakeholders. The document will be made available on the intranet. This document will be updated during subsequent lifecycle stages and changes communicated to the team as applicable.

2.0 RESPONSIBILITIES

The following responsibilities apply for all personnel undertaking activities covered by this document.

Role Responsibility

General Manager, Field Operations

a) Provide a safe system of work where persons are not exposed to hazards by ensuring that where reasonably practicable, any work involving risk to health, safety or the environment is eliminated, or appropriate control measures are in place to remove all unacceptable risks.

b) Ensure that all aspects of the QGC Operations Excavation



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Role Responsibility

Procedure are implemented, resourced and monitored. c) Ensure emergency response persons are trained and competent

to perform emergency rescue from a work situation d) Ensure the PTW system, which includes Excavating and Digging

as a high risk activity is effective in operation, documented, and adequately resourced in material, personnel, and skills.

e) Ensure processes for monitoring, auditing and reviewing the Excavation procedure are established and maintained.

Field Operations Manager a) Maintain a PTW system that covers Excavation, to ensure that work will be undertaken on QGC work sites with adequate control measures in place to reduce risk to ALARP.

b) Ensure that the PTW System, including Excavation, is reviewed regularly to ensure compliance with regulatory and QGC standards, policy and procedural requirements.

c) Ensure that identified non-compliances are reported, thoroughly investigated and remedial actions closed out.

d) Facilitate Excavation consultation and communication processes across QGC operations for review of the PTW System across all levels. Ensure Management of Change Processes are in place where required.

e) Ensure that information, instruction, training and supervision of all personnel is provided to enable them to perform their work such that their exposure to the hazards on QGC sites is as low as reasonably practical.

f) Appoint Endorsing Authorities for high risk tasks involving Excavating and Digging.

g) Implement a process to ensure the design, modification, purchase and/or hire of plant, equipment and PPE used for Excavation complies with all applicable statutory requirements and this procedure.

Area Superintendent a) Ensure competent personnel are appointed to manage the Excavation procedure for the site.

b) Ensure that there is a system to regularly inspect and maintain in proper working condition all plant, equipment or PPE used for Excavation on QGC sites.

c) Ensure the development, maintenance and regular review of hazard and equipment registers for the site that support the Excavation procedure. This equipment will be tested and certified for use by licensed and competent persons.

d) Ensure emergency response people, systems and processes are in place for the site. This includes appointing appropriately trained and competent personnel and conducting a full scale emergency response drill at least annually.

e) Auditing the Excavation procedure for the site on a regular basis to ensure compliance.

f) Ensure that all employees and contractors using the Excavation procedure are informed of its requirements; are trained and competent and understand the need for compliance.

g) Ensure the Excavation procedure is understood and complied with by all employees and contractors, including monitoring the effectiveness of the Excavation procedure within their work area.

h) Ensure that all employees and contractors involved in any works related to the Excavation procedure are trained and competent and comply.



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Role Responsibility

Area Owner a) Ensure the Excavation procedure is understood and complied with by all employees and contractors, including monitoring the effectiveness of the Excavation procedure within their work area.

b) Issue a TAN for the work to proceed when satisfied that all controls listed on the PTW and supporting PTW certificates have been implemented.

c) Ensure that all tasks in their area are monitored during the course of the work.

d) Issue a Proximity TAN when satisfied that the proposed task in close proximity to their area does not present a hazard to any activities conducted on their real estate.

Permit Holder or Team Leader

a) Promote a proactive approach to the Excavation procedure, where employees and contractors understand and effectively utilize the procedure.

b) Obtain the PTW from the Permit Issuer and acknowledge understanding of the control measures stipulated in the PTW, supporting certificates and documentation.

c) Coach team members on the method of completing JSEAs, with specific focus on Excavation.

d) Step through the SWMS, JSEA, rescue plan and other supporting documents under the PTW, prior to work commencing, with all parties working under the PTW. Review and approve JSEA for the task and ensure that the hazards have a residual risk level of medium or low.

e) Monitor the implementation of control measures as per the SWMS and JSEA and provide ongoing supervision and control while the task is being completed under the PTW.

f) Ensure all persons performing high risk work hold the relevant competencies/licenses and are trained and competent to perform the work.

g) Ensure all equipment used meets the relevant Australian Standards and is fit for purpose.

h) Ensure relevant equipment is inspected and where evidence of excessive wear or mechanical malfunction the equipment is repaired tested & re-certified for use or replaced.

e) Ensure Excavation training and coaching is provided to applicable employees and contractors within their area of responsibility.

i) Obtain Proximity TAN as identified on the PTW before a TAN is obtained for task to commence.

j) Obtain TAN from Area Owner to commence task. k) Ensure during the handback process that the area is left in a safe

condition and the PTW / TAN is closed out. a) Ensure the correct tools and equipment are identified to be used

to complete the task. l) Where conditions change stop work activities and review the

PTW with the work group when the supervisor and or workers foresee any new hazard during the course of work that is not already covered by the SWMS or JSEA. If variations to PTW may be required, suspend all work and contact the Area Owner immediately to initiate a review and authorisation of the proposed variation.



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Role Responsibility

Work Party Member a) Participate in the review of the SWMS, JSEA, rescue plan and other supporting documents under the PTW, prior to work commencing.

b) Stop work activity and review the SWMS & JSEA with a Supervisor and/or work group when workers foresee any new hazard, potential issues or scope of work changes during the course of the task.

c) Ensure individual familiarity with the approved PTW content, including Excavation procedure requirements and comply while completing the task.

d) Will ask questions and clarify SWMS content before signing onto a SWMS or JSEA within the PTW form.

e) Will not perform any work unless trained, competent and holding relevant, licences/certifications for the task at hand.

f) Will familiarise themselves with work hazards and relevant controls (including isolations) and will not commence work unless all control measures identified in the SWMS and JSEA are in place.

g) Notify the Permit Holder of any damage or deficiency observed in any equipment and remove from service where required.

Permit Issuer a) Ensure that all identified high risk work is undertaken under the PTW system and that authorisations are obtained from Endorsing Authorities for Excavation when required.

b) Review and approve the SWMS, PTW and supporting documentation - specifically Excavation - prior to issuing to the Permit Holder.

c) Ensure all persons performing high risk work hold the relevant certificates/licences and are trained and competent to perform the work.

d) Ensure all controls necessary for safe work involving Excavation are documented in the SWMS and PTW and its supporting documentation (Certificates and plans).

e) Ensure any Proximity TAN requirements are identified and brought to the attention of the Permit Holder.

f) Recommend suitable tasks for inclusion on the Approved Task List

Endorsing Authority a) Within their expertise ensure that all controls for specified high risk work are documented in the SWMS, the PTW and the PTW Certificate/s.

b) Certify on the PTW Certificates that all controls are appropriate for the task.

c) Provide advice to the workforce on their area of expertise.

d) Ensure processes for monitoring, auditing and reviewing the PTW system are established and maintained.

HSSE Manager a) Ensure the Excavation procedure complies with BG Group and Australian Regulatory requirements.

b) Ensure the Excavation procedure is audited as per the audit schedule and monitor close out of non-conformances.

c) Provide advice on Excavation best practice for continuous improvement.

d) Ensure this procedure is reviewed and kept-up-to-date. e) Ensure Excavation training and mentoring is provided to

applicable persons as per the requirements of this procedure.



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Role Responsibility

f) Ensure that identified non-compliances are reported, thoroughly investigated and remedial actions closed out.

g) Ensure incident investigations are conducted and corrective actions implemented for any incident involving Excavation.

h) Facilitate Excavation consultation and communication processes across QGC operations for review of the PTW System across all levels. Ensure Management of Change Processes are in place where required.

PTW Coordinator a) Provide guidance on PTW system, including any proposed temporary deviations to all parties as required. This includes oversight of the Excavation procedure in line with PTW procedural principles.

b) Ensure that the Excavation procedure is reviewed regularly to ensure compliance with regulatory and QGC standards, policy and procedural requirements.

c) Verify all identified high risk work is undertaken under the PTW system and is consistently applied across all parts of the operation.

d) Ensure the Excavation procedure is audited as per the audit schedule and monitor close out of non-conformances.

3.0 RISK MANAGMENT 3.1 Hazard Identification

Hazards to be considered in excavation and trenching works include (but are not limited to):

underground essential services – including gas, water, sewerage, telecommunications, electricity, chemicals, and fuel or refrigerant in pipes or lines;

the fall or dislodgement of earth or rock;

falls and falling objects;

inappropriate placement of excavated materials, plant or other loads;

the instability of any adjoining structure caused by the excavation;

the instability of the excavation due to persons or plant working adjacent to the excavation;

the presence of or possible inrush of water or other liquid;

road traffic obstruction caused by the excavation or trench;

hazardous atmosphere in excavation or trench from leak of gas or flammable liquids from above ground leaks or spills, vehicle/machinery exhaust fumes; or poor ventilation;

vibration;

lifting and handling hazards (e.g. from scaffolding being lowered into the excavation);

buried munitions;

confined space;

health and ergonomics risks associated with manual excavation techniques;

welfare and sanitation risks associated with remote/temporary worksites, and

contaminated soil.



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For excavations and trenches across roads, the control of traffic and pedestrians must be considered in the SWMS. Consideration must be given to preparing a traffic management plan.

Controls for all hazards identified must be recorded on the SWMS.

3.2 Risk Assessment (Safe Work Method Statement)

A risk assessment (SWMS) must be undertaken by a competent person as part of the work planning process. The SWMS must be developed in accordance with QGC Safe Work Method Statement Procedure (QCOPS-BX00-HSS-PCE-000005).

The SWMS must be retained with the PTW documentation for the excavation and may be used for subsequent excavations at the same site if the conditions remain constant and unchanged from the development of the original SWMS.

The SWMS must consider the reason for the excavation and all applicable hazards associated with the work and the particular work site. The following provides a list of hazards that must be considered as a minimum:

local site conditions, including access, ground slope, adjacent buildings and structures, water courses (including underground) and trees;

depth of the excavation;

soil properties, including variable soil types, stability, shear strength, cohesion, presence or ground water, effect of exposure to the elements;

proximity of live sewerage service line to the excavation;

potential for sewerage seepage, or methane gas/vapour migration;

the condition of the soil substrate;

fractures or faults in rocks, including joints, bedding planes, dip and strike directions and angles, clay seams;

any specialised plant or work methods required (for example ground support);

the method(s) of transport, haul routes and disposal;

what exposures may occur, such as to noise or UV rays;

the number of people involved;

the need to enter/work in the excavation;

the possibility of unauthorised access to the work area;

local weather conditions, and

the length of time the excavation or trench will be open.

The SWMS must consider whether the excavation can become a confined space as defined in the QGC Confined Space Entry Procedure QCOPS-BX00-HSS-PCE-000003. If so, those requirements must apply in addition to the requirements of this procedure.

The SWMS must consider all reasonably foreseeable hazards and determine the required control measures for these hazards. Based on the outcome of the risk assessment, all necessary safety systems and equipment including PPE must be provided and an emergency plan must be prepared.

The JSEA process and/or Step back process must identify any new/ unique hazards specific to the work area and ensure all persons involved with the activity are aware of the hazards, and controls required commencing works in a safe manner.



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3.3 Risk Control

The hierarchy of controls must be implemented in the order specified and in combination (if no single measure is sufficient) to minimise the risk of excavation to the lowest level reasonably practicable.

Most Effective

Least Effective

Elimination Can the need for excavation be avoided by installing cables or pipes above ground in pipe racks, cable racks or existing culverts?

Substitution Can an alternate method such as moling, directional drilling or other non- destructive pipe laying technique be used instead of excavating?

Engineering / Isolation

Can barricades, barriers, fencing or handrails be put in place to prevent the risk of falls?

Can benching, battering or shoring the sides of an excavation reduce the risk of ground collapse?

Administrative Controls

Can JSEA’s, procedures, SWMS, PTW, emergency plans, toolbox talks and regular inspections minimise exposure?

Personal Protective Equipment

Can hard hats, hearing protection and high visibility vests protect workers from excavation hazards?

4.0 DESIGN

Designs must optimise the layout, constructability, operability, maintainability and accessibility of facilities, whilst at the same time minimising the requirement for excavation or trenching during construction and subsequent operation.

Excavations and any supports must be designed in accordance with acceptable engineering principals and standards.

5.0 PLANNING

All excavation and trenching work must be planned.

Prior to any excavation works taking place, the ground conditions must be assessed. This can be achieved through boreholes, trial pits or information from previous or current work in the area. If none of the above is possible, the ground conditions must be examined when excavation commences.

Planning must consider:

nature and/or condition of the ground and/or working environment;

nature of the work and other activities that may affect safety;

static and dynamic loads near the excavation;

energised power, live gas services;

link up of existing sewerage;

interaction of other work activities;

site access;

management of surrounding vehicular traffic and ground vibration;

nearby structures;

type of equipment used for excavation work;

public safety;

provision of adequate amenities; and



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procedures to deal with emergencies.

5.1 Survey of Area to be Excavated

Prior to physical work commencing the Permit Holder (or person applying for the permit) must initiate a thorough site or route survey to identify buried and overhead services, obstructions and hazards.

The results of this survey must be accurately recorded and documentation attached to the PTW.

The excavation or trench must be sited so as to minimise excavation risks, and the possibility of damaging other services in the vicinity.

For emergency work the relevant information should be obtained as soon as possible after work starts.

5.2 Adjacent Buildings or Structures

Excavation work, which is likely to reduce the security or stability of any part of a structure, must not commence or continue unless adequate steps are taken before and during the progress of the work to prevent the collapse, or partial collapse of a structure.

Unless the excavation is in stable rock, as determined by a competent person, any excavation that is below the level of the footing of any structure or retaining wall that could affect the stability of the structure must be secured by a suitable ground support system. Suitable supports for the structure may also be required.

In all cases the Permit Holder must ensure that adjacent buildings or structures are not adversely affected by vibration or concussion during the excavation work. Precautions must be taken to ensure that buildings or structures containing equipment sensitive to shock and vibration are adequately protected if temporary relocation of the equipment is not possible.

Excavation work must be carried out in a manner that does not cause flooding or water penetration to any adjacent building or structure.

5.3 Location of Underground Pipes and Cables

For excavations within operating plant boundaries, appropriate drawings must be examined to locate all underground pipes and cables.

For excavation sites outside Operating Plant boundaries, it is a statutory requirement to contact the national ‘dial before you dig’ service (www.1100.com.au) and obtain a clearance before any excavation work starts.

A secondary means of verifying the location of the underground service/s must be used, such as potholing, prior to any mechanical excavation commencing.

Greenfield

A Greenfield construction zone assessment must be undertaken for all Greenfield sites.

Greenfield

A Greenfield construction zone assessment must be undertaken for all Greenfield sites.



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5.4 Excavation to Expose Existing Pipes or Cables

All underground pipes and cables in the excavation site must be located using instrument cable and pipe locators, and mechanical probes, as necessary.

In all cases where mechanical excavation is used, the exact location of underground pipes and cables must be verified by hand excavation (with a hand shovel) when mechanical excavation approaches within 500 mm of the pipes or cables. Mechanical excavation is not permitted within 500 mm of existing pipes or cables. Completion of excavations to expose pipes or cables must be done by hand.

Mechanical excavators must always utilise a machine bucket fitted with a blunt scraper bar to minimise damage to underground services; buckets with ‘tiger teeth’ must not be used.

Appropriate controls must be implemented to prevent accidental ignition of a possible hazardous concentration of flammable vapour or gas and where relevant the work area must be monitored using approved and correctly calibrated gas detectors prior to and during the work, to determine the presence and concentration of flammable gas. Refer to AS 2885.3:2001

5.5 Excavation Around Live Underground Services

The SWMS for excavation around live underground services must be approved by the Area Operations Superintendent and compliant to AS 2885.3:2001.

The SWMS must consider:

the type of service;

precisely locating existing live service by ‘potholing’ or exposing the service by hand;

marking the position of these live services;

relocation of these services;

excavation methods;

PTW and Certificates;

use of spotters;

minimum approach distance; and

removal of material below the live service (if required).

A minimum limit of approach distance of 1 metre must apply to mechanical excavating – without a spotter present - towards live underground services (dependant on workplace risk assessment a greater limit may be required).

A minimum limit of approach distance of 0.5 metres must apply to mechanical excavating – with a spotter present - towards live underground services (dependant on workplace risk assessment a greater limit may be required).

Refer to AS 2885.3:2001

5.6 Excavation underneath electrical hazards or overhead obstructions

Specific work control procedures must be developed for work under overhead power lines that must include the use of a competent spotter and adhering to exclusion zones. Written safety advice must be obtained from the Asset Owner. Refer to QGC Safe Access to Low Voltage Electrical Apparatus Procedure (QCOPS-BX00-HSS-PCE-000011) and QGC High Voltage Isolation and Access Procedure (QCOPS-BX00-HSS-PCE-000001) and Electrical Safety Act 2002.



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5.7 Selection and Transport of Excavation Equipment

The excavation equipment to be used must be selected with consideration to the work to be done and the location of the work site (particularly when the work is to be carried out in a public area).

The equipment must be transported to the work site on the appropriate trailer, truck or carrier.

Equipment must be inspected prior to allowing it onto the worksite to ensure it is free of any soil or weeds from previous jobs.

All ride-on tracked, wheeled or rubber tyre vehicles entering the excavation must be fitted with a certified FOPS cab or canopy as a minimum and ROPS.

Tracked, wheeled and rubber tyre heavy equipment working around the excavation should also be fitted with a ROPS cab or canopy.

All excavators working on the site must have ROPS/FOPS cabs or canopies.

All electrical and fuel powered equipment introduced into a trench or operation must be in good mechanical and electrical order.

5.8 Working Room and Working Alone

Space in an excavation is generally limited; care must be taken to ensure that there is sufficient separation between individual workers and different tasks to avoid accidental injury.

Workers must also be separated from active digging faces and active dumps to avoid being struck by falling material, by an excavator bucket or by any part of the excavator within the excavator swing radius.

No persons must work alone unless there is another person close by that can render assistance or a dedicated stand by person.

5.9 Work at Night/ Lighting

The lighting system must ensure the safety of people to the extent that the lighting makes hazards visible, enabling sufficient light to conduct tasks safely and evacuate the area in the event of an emergency.

Excavations in public areas and near permanent public access ways need illumination of the edges. Battery operated flashing lights placed at intervals are usually sufficient.

In deeper excavations or during times of reduced visibility, lighting may be necessary to allow work to proceed in a safe manner. Lighting must be guarded and installed to prevent damage.

Power leads must be protected from water ingress and mechanical damage. The lighting must be placed so that the level of illumination at the working area is not less than 200 LUX and access ways and working areas are free of glare and deep shadow.

All electrical items must comply with the QGC Electrical Safety Procedures.

Further information can be sought from:

AS/NZS 3012:2010 Electrical installations – Construction and demolition sites (Section 2.7 Lighting and luminaries)

AS 2293.1 – 2005 Emergency escape lighting and exit signs for buildings Part 1: System design, installation and operation (Section 5 Design of emergency escape luminaire installation)



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5.10 Backfilling

Backfilling operations must be considered during the planning process to ensure that the operation is planned and conducted safely and efficiently whilst achieving the planned standards of compaction.

Particular issues that must be considered are:

placement of material whilst persons are in the excavation;

movement of machines above and around the excavation;

removal of shoring to ensure that workers are not exposed to unsupported trench walls;

vibration effects from compaction equipment;

exhaust gases from compaction equipment;

manually lifting compaction equipment in and out of the trench; and

marking of services with underground marking tapes and surface markings as per local legislative requirements.

6.0 PERMIT TO WORK (PTW) FOR EXCAVATION

A PTW is required for all excavations deeper than 300 mm in Brownfield sites, unless the excavation has been appropriately risk assessed, approved by the Area Superintendant and is listed on the sites Approved Task List (ATL).

The PTW can only be issued when the SWMS and the Excavation Certificate are complete and the control measures are in place or readily available to be installed as the excavation proceeds. The controls must consider management of the excavation and management of movement around and into the excavation as well as the reason for the excavation.

For all excavations 1.2 m or greater, a QGC appointed Excavation Endorsing Authority must review and approve/endorse all PTW applications and supporting documentation

7.0 EMERGENCY AND RESCUE PROCEDURES

The Area Superintendent must ensure a plan is prepared that outlines the arrangements that have been made to ensure the safety of workers and other persons on site in the event of an emergency situation. The emergency situation may arise during excavation works either from the risks identified during the risk assessment process or from unplanned or unforeseen natural disasters such as electrical storms, floods, fire that may present a hazard to working operations, etc.

The plan must ensure an assessment of the following occurs as a minimum:

the nature of the hazard and possible emergencies;

the size and location of the place of work;

the number and mobility of persons at the workplace;

the safe and rapid evacuation of persons;

emergency communications (including communication with service owners);

Greenfield

A PTW is required is Greenfield sites as determined by SWMS, JSEA and Permit Issuer.



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appropriate medical treatment of injured persons;

location of rescue equipment including shoring material;

location of pumps;

gas monitoring equipment;

the location of the nearest emergency services; and

access for rescue vehicles and personnel.

Control measures within the emergency plan must include:

development and communication of a warning system;

development and communication of safe and rapid evacuation procedures, including injured persons;

having trained personnel to oversee evacuation and rescue procedures until emergency authorities arrive;

appropriate medical treatment and evacuation of injured persons;

shutting down of work, including plant and electrical equipment;

provision of fire fighting and rescue equipment at appropriate locations; and

display of evacuation procedures in appropriate location(s) at the work area.

All personnel on site must be made aware of the plan and how it relates to their particular work area.

8.0 PPE AND SAFETY EQUIPMENT

The appropriate Personal Protective Equipment (PPE) must be used by personnel operating excavating equipment and working in the vicinity of excavation work.

All personnel working within or in the region of the trench or excavation must wear high visibility clothing.

In addition to QGC minimum field PPE requirements, other PPE may be required if persons are exposed to hazardous substances or contaminated soils, are entering confined or restricted areas, or are conducting activities within the excavation/trench that require additional precautions, e.g. double face eye/face protection for grinding works.

9.0 INSPECTIONS OF EXCAVATIONS

The Area Superintendent must ensure that a system of regular inspections of trenches and excavations are in place. Inspections must be conducted daily by a competent person for trenches over 1.2 metres in depth in which persons are working. Inspections in trenches less than 1.2 metres in depth must also be conducted daily or as determined by risk assessment (SWMS).

Inspections must be undertaken after:

any ground slip or collapse of a section of wall;

any substantial rain event which may have led to water ingress;

any change in ground conditions are encountered, i.e. dry weather;

every blast;

any hazardous substances or material is encountered; and

any change in site conditions e.g. when other construction activities are taking place in the vicinity.



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All deficiencies noted must be made good; any remedial or other works necessary must be carried out as soon as possible and, in any intervening period, no other works must be carried out in the excavation.

Copies of the inspection results as well as copies of the excavation and other documents pertinent to the job must be held with the PTW documentation at a prominent location in the working area.

Note: Anyone may stop the excavation works if the works appear to be unsafe.

10.0 MANAGING EXCAVATION WORKS

10.1 Excavation Register

In order to monitor and track excavation works being undertaken, to manage the likelihood of additional hazards created from adjacent excavation works and verify the currency of issued permits, an excavation Certificate register must be maintained.

The excavation register must record the identification numbers of all approved requests to excavate and their Excavation Certificates.

10.2 Access and Egress

Safe and sufficient means of access and egress must be provided at all times whenever and wherever persons are working in an excavation:

a minimum of two access/ egress points for every 9m or trench must be applied;

ladders may be used but they must extend at least 1 metre above the top; and

where possible, ladders must be placed at or near junctions or corners of an excavation.

If an excavation is more than 1.2 metres deep the following control measures apply to entry:

the Permit Holder must ensure there is ladder access installed at least every 9 metres of length;

for excavations shorter than 9 metres, an emergency means of access must be provided: this can take the form of a second ladder placed near the excavation that can be installed quickly when necessary or have ingress / egress ramps either end of trench;

no person must work alone in excavations or trenches and the Permit Holder must enforce this; and

entry points must be secured when work is suspended and the excavation is left unmanned, to avoid pedestrian and vehicle encroachment. This protection will include, where appropriate, the use of lighting and reflective signage.

Greenfield

Access / egress ramps must be constructed for all Greenfield excavations.

Greenfield

Excavation register does not apply to Greenfield sites.



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10.3 Limits of Approach

A limit of approach table must nominate the specified clearances required when working around underground services (and can include overhead services). The limits of approach table must be confirmed by the Area Superintendent and reflect the limits as specified by the service owner/ local legislative requirements or guidance material.

Relevant details of this table must be included within QGC’s Excavation Certificate (QCOPS-BX00-HSS-CER-000002).

10.4 Service Identification

To ensure standardisation across the workplace areas, underground services and identification markers such as flags or survey pegs must be marked (colour coded) in a consistent format to be readily identifiable. Details of the colour coding should be included as part of the Excavation Certificate.

As a guide, section 6.4 below (as per AS 1345:1995 Identification of the contents of pipes, conduits and ducts), highlights common services and associated colours.

Identification survey pegs must be uniquely labelled / numbered and include information referencing service type, pipe/conduit configuration and known service depth.

10.5 Colour Codes for Service Identification

Electricity - Orange

Gas - Yellow

Water (Fire services) - Red

Telecommunications - White

Sewerage - Black

Water (potable) - Green with blue band

Storm water - Green

10.6 Temporary services

Where electrical cables or other services are laid in trenches for temporary service supply, they must be protected (conduits, slabs, etc) and marked, in accordance with the relevant legislative and Australian Standards requirements.

10.7 Excavation Depth Criteria

10.7.1 Depth less than 1.2 metres

Excavations of less than 1.2 m need not be shored, benched or battered. However consideration must be given to the expected level of risk to workers and to the public. The following issues must be considered in assessing the expected risk:

soil type and condition e.g. acid sulphate soils;

is the public exposed?

what protection and barricading is required?

what is the expected duration of exposure?

what is the proximity of heavy equipment to persons in or around the trench?

is the water table above or below the trench bottom? and



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is de-watering required, and if so, will it affect the stability of the trench?

10.7.2 Depth 1.2 metres or greater

Excavations and trenches deeper than 1.2 metres must be shored, benched or battered, or any combination of these on all sides of the trench. Where the site assessment indicates an unacceptable risk of injury to personnel through excavation collapse, or where there is a possibility of the sides of an excavation becoming unstable (e.g. because of ground conditions and/or superimposed loading), the excavation must be supported irrespective of depth.

As an alternative to shoring, at the discretion of a competent person, the sides of the trench may be stepped or sloped to the natural angle of repose of the loose spoil, and by an angle of no more than 45° between the floor of the excavation and the sidewall.

A competent person must examine the ground conditions and submit a statement in writing detailing the findings of the examination (as part of the pre-planning for the PTW process).

This statement must include the type(s) of ground encountered, the calculations used in deciding the method of protection required and any particular issues that need to be addressed. This statement must be signed by the competent person and kept on file in the project office.

The Area Superintendent must ensure that all legislative requirements are complied with.

For all excavations 1.2 m or greater, a QGC appointed Excavation Endorsing Authority must review and approve/endorse all PTW applications and supporting documentation

10.8 Narrow Trenches, Ditches and Small Holes

Shoring, benching and battering is generally not required if it is impossible for a person to fully enter the trench, ditch or round penetration, irrespective of the depth of the excavation.

However, these narrow excavations still constitute a hazard for other reasons, and therefore due consideration must be given to implementing effective controls for those hazards, i.e. covering, barricading etc.

Narrow excavations, i.e. trenches require a PTW to be issued prior to work commencing.

10.9 Shoring and Ground Support

Shoring or ground support (in the form of rock bolts, shotcrete etc.) must be installed as per the engineered design requirements.

In circumstances where shoring or other similar support systems are used, they must be installed without delay as the excavation progresses. The shoring must extend at least 300mm above the edge of the excavation or a fender board of the same height provided.

Workers installing the system must be given clear instructions including drawings and sketches.

All shoring must be inspected on a daily basis prior to any work commencing.

Additional inspections must be conducted and documented after any fall of the sides or working face or after blasting.

Where the installation of a support system differs to the requirement of the design plans, all changes must be referred back to a competent person for approval.



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Shoring must be dismantled in the reverse order to its installation.

Workers must never work outside the protection of ground support systems, no matter what the circumstances.

10.10 Benching and battering

Benching and battering may be used where space and conditions permit as a substitute to shoring operations.

The overall slope of a benched or battered wall may not exceed 45 degrees to the horizontal unless certified in writing by a competent person or geo-technical engineer.

Each bench cut into the side of a trench must be no higher that it’s width without the written approval of a geo-technical engineer and must comply with relevant Australian Standards.

Note: Positive identification of services must occur within a minimum of 3 metres (dependant on workplace risk assessment) of the planned excavation; this includes the area used to bench or batter.

10.11 Fall prevention

The risk assessment (SWMS) must determine the appropriate controls required to protect persons from falls and from falling objects. Persons, tools and materials can fall from ladders, work platforms and scaffolds injuring those below. Persons or objects can fall into the excavation from above.

The following measures to prevent falls should be considered:

pedestrian detours, which should be clearly defined and protected;

use of intermediate platforms for deep excavation;

provision of a safe means of movement between different levels of the excavation;

provision of an adequate fall arrest system; and

backfilling as work progresses

Note: Loads must not be suspended or travel over a person under any circumstances.

Control measures must be properly installed and maintained until the work is completed or until there is no longer any risk of persons falling into the excavation.

The risk of material falling into an excavation increases during high winds. Provision of overhead protective structures must be assessed and documented where the hazard of falling objects has been identified.

Every part of the trench or excavation where there is a likelihood of a person falling 1 metre or more must be provided with barricades or handrails as soon as possible after excavation (dependant on workplace risk assessment, in particular considering volume of traffic (pedestrian or vehicle) near the excavation etc). Barriers and barricades must be located a minimum of 1.0 m from the edge of the excavation.

Walkways across trenches must be fitted with handrails. For trenches greater than 1.8 metres the requirements of the Working at Heights Procedure (edge protection) apply.

Barricades or handrails can be removed to allow access or movement of plant, or materials. Once access is no longer required the barricades or handrails must be re-instated.

AS1657 Fixed platforms, walkways, stairways and ladders — Design, construction and installation describes the requirements for walkways that must apply to excavations. AS 1657 requires:



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guard rails must be at a height above the walkway of not less than 900 mm or more than 1100 mm;

another rail is required with a gap of no more than 450 mm between it and the top of the toe board or the top rail unless the there is a sheet of sturdy mesh, sheeting or other material between the top rail and the toe board;

toe boards must extend at least 100 mm above the surface of the walkway and the gap between the toe board and the walkway must not exceed 10 mm; and

the minimum width for walkways is 550 mm for walkways with guard rails on both sides otherwise the minimum width is 600 mm. The recommended width for two way traffic is 900 mm.

Note: refer also to QGC Fall Prevention Procedure (QCOPS-BX00-HSS-PCE-000004)

10.12 Barriers, barricades and signage

The work area immediately adjacent to an excavation or trench must be secured to prevent unauthorised access of persons into the work area. The work area must be secured using the most appropriate method that may be any one, or a combination, of the following:

barricades;

barriers;

fencing; and

handrails.

Barriers or stop blocks must be installed where there is an identified risk of cranes, dumpers, tip trucks, etc. manoeuvring too close to the edge of the trench and endangering its stability or falling into the excavation.

Care must be taken with selecting barricading material. Substantial barriers or barricades must be used instead of materials such as webbing fences.

Webbing fences must only be used for pedestrian traffic management, not for fall protection. Clear and sufficient signs must be posted to at the entrances to the excavation to highlight the excavation hazard and any particular hazards encountered within the excavation such as a confined space.

10.12.1 Public access

Particular care must be taken in and around areas where the general public may have access to a trench.

In remote locations or where the general public may not have access, the Area Superintendent must review requirements for barricading but must ensure that adequate hazard demarcation and protection is provided.

For excavations in the public domain or within third party property or land, the protective system must display the name of the asset responsible for the work and relevant contact telephone numbers for reporting defective barriers or unsafe excavations.

10.12.2 Work Near Roads or Footpaths

Excavation and trenching works must not put the public or workers at risk.

Local government legislation/guidance information may prescribe clearances and approvals required prior to working in the vicinity of roads or footpaths. Local council approval/permit must be attached as supporting documentation to the QGC PTW.

As a minimum, AS 1742.3—2009 Manual of uniform traffic control devices Part 3: Traffic control for works on roads provides prescriptive detail regarding the type of barriers required to protect workers and the public in addition to signage requirements and this must be complied with.



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10.12.3 Specific requirements

Trenches must be back filled as soon as practical or as a minimum covered with a substantial cover or barricaded. Trenches must not be left open overnight in vehicle or pedestrian traffic areas.

10.13 Movement of Vehicles and Plant Near, or Over, Excavations

Vehicles and plant must not be brought alongside excavations or trenches unless it is essential to do so. A competent person must approve any such movements.

Vibrating and impact machinery must be operated and kept well clear of excavation/trench sides.

It may be necessary to bridge excavations temporarily to provide access to premises or to permit the passage of vehicles when work is temporarily suspended. In such situations a competent person must determine the use and design of temporary bridging.

When road plates are used the following precautions must apply:

the trench sides must be stable or suitable supported(taking into account anticipated traffic loading);

no person must work under a road plate( unless traffic is halted);

the plate should be of sufficient length to be firmly supported for at least 600 mm on each side of the trench and of a width sufficient to provide a distance of at least 250 mm from the wheels of vehicles to the edge of the plate( or as determined by a competent person;

the thickness of the plate should be sufficient to support the range of traffic encountered;

ramps should be formed of a suitable material where the road plate is proud of the road surface;

when the site is not attended, or when subject to frequent use by heavy vehicles, consideration should be given to securing the road plate(s) by pinning or sinking into the roadway.

appropriate ramp warning signs must be displayed;

all road plates on unmanned sites should be submitted to visual inspection on a regular basis;

appropriate lifting and handling precautions must be taken to ensure that the road plates are transported, installed and removed safely; and

fabricated bridges must have engineering certification for load bearing capacity

10.14 Confined Spaces

Risk assessment must consider the potential for the excavation to be a confined space. If a confined space risk is identified, the confined space must be eliminated or, if this is not possible, appropriate risk control measures must be implemented and documented. QGC Refer to Confined Space Entry Procedure (QCOPS-BX00-HSS-PCE-000003).

A Confined Space Certificate is required before entering an excavation if the excavation is determined to be a Confined Space (QCOPS-BX00-HSS-CER-000001).

The Area Superintendent must ensure that the requirements for confined spaces in trenches and excavations are clearly defined and understood.

10.15 Hazardous Substances

Hazardous substances introduced into the workplace must be risk assessed, which must identify training needs, personal protective equipment (PPE) and relevant safe work systems.



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Less hazardous substances must be used wherever possible. A MSDS (material safety data sheet) register must be maintained on site and the MSDS must be readily available in the area where the substances are used.

10.16 Site contamination

Contaminated sites require special management during excavation and trenching operations. Persons may be exposed to contamination in the soil through inhalation, ingestion (swallowing) and through skin absorption. These substances may include heavy metals, hydrocarbons, insecticides, asbestos, silica dust, combustible material, or biologically harmful material from buried wastes.

If it is determined that these substances may be present or if they are encountered during the excavation process, then a system to eliminate or control these hazards must be investigated and implemented.

Consideration must also be given to the storage and eventual treatment or disposal of these materials

The Area Superintendent must ensure that any material imported as fill or exported as waste material has been evaluated for contamination.

In some circumstances, exporting contaminated material from a site requires local/State government approvals and these must be obtained before the material is allowed to leave the site.

10.16.1 Equipment oil/fuel spill response

The Area Superintendent must designate particular areas for the regular dispensing or draining of hydrocarbons. All hydrocarbon dispensing areas must incorporate safeguards to manage the risk of hydrocarbon spillage, in compliance with AS1940:2004.

The techniques for controlling spills depend on the spill environment.

The Area Superintendent must ensure:

Relevant staff are trained in appropriate spill control techniques

Spill kits are located in areas regularly associated with the use of hydrocarbons

Specially equipped spill kits are available when working near or on water.

All staff are aware that all hydrocarbon spills must be reported to the Area Superintendent or their delegate, who will initiate an incident report following the procedure managing HSE Incidents

Waste resulting from a spill clean-up is handled and disposed of appropriately.

10.16.2 Acid sulphate soils

Acid sulphate soils are common in low-lying coastal areas and represent a significant environmental threat when unearthed.

The Area Superintendent must ensure geo-technical assessment of the site investigates the potential of encountering acid sulphate soils during trenching and excavation operations.

Personnel involved in excavations where acid sulphate soils are an identified risk must receive training in how to recognise acid sulphate soils and how to manage the risks.

Acid sulphate soils must be managed and treated through the application of lime or by ensuring that the affected area is maintained in a water submerged state to control oxidation.



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10.17 Underground services (DIAL BEFORE YOU DIG)

When mechanical excavators (or machine powered surface breakers) are to be used, it is essential that the integrity of all underground services in the vicinity is maintained through its location and exposure by hand digging in advance. Third party service owners must be consulted to ascertain protective measures to be applied when working in the vicinity of their services and for the minimum proximity distance to be applied when using mechanical equipment. To ensure the safe use of any mechanical excavator, consideration should be given to the use of a competent safety observe/spotter. If any damage is caused to underground services, it must be reported as soon as possible. Work must only continue once the damage has been repaired, or it has been confirmed by a Competent Person that it is safe to do so.

Similarly when pipelines, mains or ducts are to be installed by non-destructive techniques (e.g. moling, horizontal directional drilling) all other underground services in the vicinity of the route must be located and exposed by hand digging in advance. Where the planned route crosses above other buried services then the safe passage of the pipe laying tool must be verified by opening an excavation immediately above the verified position of the third party services to an appropriate depth.

Due care must be exercised as work proceeds to e

nsure that existing underground services are not damaged, particularly with respect to electrical cables. Cables and pipe locators must be used to confirm the position of existing cables and other metallic underground services prior to the commencement of work, and also at frequent intervals as excavation proceeds.

Consideration must be given to isolation electrical services where practical (buried and overhead)> Warning notices must be erected on the approaches to overhead power lines or obstructions.

Mechanical plant must not be used within 0.5 m of live services.

10.18 Excavation Material

Excavation Material must normally be placed along the side of the excavation, and care must be taken to prevent the weight of excavation material contributing to excess loading and collapse of the trench side. To provide adequate working space and to avoid the danger of debris falling into the trench, sufficient space ( preferably 600 mm to 1200mm, but not less than 300 mm) must be left between the trench and excavated material.

For trenches or open excavations that shall be occupied by personnel, the minimum setback for spoil must be 1.0m.

For excavations in trafficked roads where conditions permit, consideration should be given to placing the excavated soil so as to form an additional barrier against traffic. In all cases, excavated materials must be placed so as not to cause a hazard to personnel, pedestrians or road traffic. Toe boards must be installed for deep excavations where there is an injury risk from falling spoil, tools or other objects.

Where the excavation material is to be re-used, the surface materials must be kept separate from the subsoil, so that suitable layers may be replaced in the proper order during reinstatement. Inn these circumstances the excavated material should be protected against adverse wet weather conditions or excessive drying out. Consideration should be given to covering the excavated material in order to maintain the moisture content.

Greenfield

A minimum of 1.0 m must be left between the trench and excavated material.



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10.19 Ventilation, Harmful Gases and Fumes

Where mechanical ventilation equipment is required to establish and maintain a safe environment the equipment must be monitored regularly and have the controls, including any remote power supply identified and tagged to prevent any unauthorised and / or accidental interference.

Consideration must be given to the potential for exhaust gases from equipment outside the excavation entering the workings and exhaust gases from equipment inside the workings not being carried away from the work area by natural ventilation.

11.0 ENVIRONMENTAL AND COMMUNITY ISSUES

11.1 Community consultation- Impact on surrounding community

The Area Superintendent must ensure the impact of excavation and trenching activities on the surrounding community is assessed prior to commencing work.

In particular, issues such as work hours, site access, and noise and traffic disruption must be considered and appropriate measures included in the site environmental management plan to minimise their impact.

Where appropriate, notifying the community of upcoming works must assist in lessening their impact and in some situations may be mandatory.

11.2 Noise

Provision must be made to manage noise within and around the excavation. This includes noise hazards to those around and within the excavation and noise emission from the works.

All efforts must be made to eliminate or engineer the source of the noise consistent with the hierarchy of controls.

11.3 Water management

Provision must be made for management of water entering the excavation and of draining water from the works.

Sources of water ingress are seepage, flooding from other existing watercourses, flooding from storm events, flooding from burst water mains and sewers in the excavation and similar. Tidal or stream effects may also impact excavations in coastal or fluvial environments.

Disposal of water must be given careful consideration.

Water that has occupied a trench or excavation for even a short period may not be suitable for direct discharge to local waters or the storm water system.

The Area Superintendent must ensure the quality of water requiring disposal has been assessed and that disposal meets local/State government regulations.

11.4 Water logged ground.

Where waterlogged ground conditions are expected and water-removing equipment is required, it is usually satisfactory to pump from sumps within the excavation. Where in trench pumps are used for prolonged periods, particularly in ground of a sandy or silty nature, it may be necessary to install suitable filters behind sump linings to prevent loss of ground which could affect stability filters behind sump linings to prevent loss of ground which could affect stability. Similar filters may be necessary along the trench sides in extreme conditions. Trench sumps must not be excavated to such a depth that they present a hazard.



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Alternative water removing methods must be considered in any of the following circumstances:

where it is proposed to excavate through running sand or water bearing peat;

where pumping from trench sumps is inadequate to keep trenches free from water;

where deep excavations have to be made in waterlogged ground; and

where excavations are to be present for a considerable period of time in waterlogged ground.

Alternative measures include sumps external to the excavation, well points, electro-osmosis and consolidation by freezing or by chemical process. Where it is anticipated that such measures will be needed, the advice of a suitability qualified engineer experienced in such works must be sought.

11.5 Erosion from adverse weather

Keys to effective control are:

minimise the erosive effects of concentrated flow;

reduce total soil disturbance;

reduce total slope length and gradient;

provide stabilising ground cover protection from the effects of raindrop impact.

11.6 Plant wash down (seed transfer) for excavation equipment and transport.

Vehicles and machinery are recognised as a major source spreading declared weeds. Plant and equipment must arrive on, and exit the site clean and free from a build up of dirt or plant material.

Wash down facilities must be established as identified in the WAP or WP risk assessment, i.e. in a known declared weed area.

Wash down areas must be:

selected to minimise the risk of spread (on or off-site);

regularly inspected for weed seedlings which may have germinated from seeds washed off vehicles etc. Any weeds must be controlled immediately; and

sited in degraded areas to minimise risk of undetected weed spread.

Where it is impractical or not possible to establish a wash-down facility consideration must be given to adopting alternative options and solutions to manage seed transfer.

11.7 Cultural, environmental or archaeological issues

Trenching and excavation operations may unearth or damage the cultural or ecological value of a site, for example remnant vegetation or aboriginal artefacts. Prior to commencing work in an area where this may

be an issue, the Area Superintendent must ensure that the cultural, ecological and archaeological value of the site has been assessed and appropriate measures are in place to maintain the values identified.

12.0 COMPLETION OF EXCAVATION WORKS

Where services are installed in trenches, care must be taken not to damage the service or any coating or wrapping during backfilling works.



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To protect pipe coatings and polyethylene pipe, subsoil fill must be clean, moist and free from sharp stones greater than 18 mm in size. Backfill soil may be sieved to meet this requirement or soil may be imported as required.

Cementatious materials must not be used as fine fill material around pipes. Fine fill material should be packed firmly around pipes or fittings to give a minimum compacted thickness of 75 mm.

When placing fine fill around large diameter pipes, or where the side gap between the wall of the excavation and the pipe is greater than 75 mm, special care must be taken to ensure firm compaction of the fine fill especially around the lower half of the pipe.

The required thickness of other levels of reinstatement will depend on the location of the excavation or trench (e.g. private land, carriageway, footway, etc.) and the requirements of the landowner or management authority. All unbound materials used in these levels must be placed in layers no deeper than 300mm within the trench and firmly compacted using approved mechanical compaction equipment.

Excavated material may be suitable for re-use as backfill material provided that the material is moist, does not contain any particles larger than 75 mm and is not uniformly graded i.e. is not single-sized.

At the completion of the work, the work site must be cleared of all rocks, soil and other debris and returned, as far as is practicable, to its original condition or finished to an agreed plan.

Drawings and other documentation must be updated to reflect any changes due to the work just completed.

Any re-vegetation of the work area must be conducted with suitable species and in consultation with relevant local government personnel.

13.0 TRAINING AND QUALIFICATION

Persons carrying out excavation or penetration work must be qualified, trained and competent for the task and for the level of risk involved.

All personnel involved in the activity must be consulted with regards to the agreed SWMS, JSEA and the controls required completing the works safely.

Specific competencies for excavation and trenching e.g. confined space must be identified during the work planning process to ensure persons have the correct competencies prior to commencing excavation works.

13.1 Supervision

A supervisor is a suitably qualified / competent person responsible for / in charge of the excavation / trenching work.



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13.1.1 Mobile plant operators

Operators of powered plant and equipment must hold all required licenses and certificates before they can operate on site or they must be a trainee being supervised by a licensed person.

All relevant documentation must be sighted and recorded on a register and confirmed by the Permit Issuer as part of the permit issue process.

All operators of powered plant and equipment must have their competency verified by an approved QGC person before they can operate on site.

14.0 AUDIT AND MANAGEMENT REVIEW

Operational procedures, work control arrangements and other requirements applicable to excavation and trenching activities must be subject to periodic audit and regular management review by the assets. The audit scope must include provision for confirming adherence to this procedure.

A detailed Annual Audit of the Excavation procedure will be carried out to examine the adequacy of the procedure in terms of the range of work activities undertaken, effective application of the procedures.

The annual audit should examine the fundamental content and compliance to the procedure, and is best performed by a person familiar with the PTW System and Excavation procedure, but independent from the Operations and Project areas in question.

All audits must comply with the QGC Audit Procedures.



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APPENDIX A – DOCUMENT DISTRIBUTION RRECORD (RACIE SHEET)

DOCUMENT DISTRIBUTION SHEET

Consulted:

Enter name/position of those required to review the document (excl. Key Consulted persons – see forward)

Dave Preston - HSSE Manager Trevor Love - Contractor - Cons Special Advisor

Carl Martin - Field GM Douglas Smith - Senior Project Manager

Joe Gogarty – Permit Authority Rob Ries – Training & Competency Supervisor

Brendan Galloway - Lead HSSE Advisor Louise Edgley - HSSE Mgt Systems & Audit Advisor

Vicki Wright – Maintenance Supervisor Larry Buckeridge - Sen Project Manager

Nicole Copeland - Principal Safety Advisor Richard Schokman - Operations Support Manager

Andrew Raguse - Maintenance Superintendent

Eric Marsden – Area Operations Superintendent(Kenya)

Charles Knecht - Field Operations Manager Carlos Abel - Area Operations Superintendent(Ruby Jo)

James Donnelly – Water Treatment Super Ken Krieger – Well Compliance Coordinator

Andrew Buhner – Control Room Super Philip Christopher – Control Room Supervisor

Andrew Austin – Control Room Supervisor Russell Schroder – Control Room Supervisor

Sonia Cogo – Permit Authority Trevor Smith – Permit Authority

Brian Boehm – Permit Authority Bill Von Harten – Permit Authority

Mitchell Peacock – Permit Authority Rob Demaine – Permit Authority

Rob Bailey – Permit Authority David Horsford – Permit Authority

Kirk Russell – Permit Authority Shane O’Brien – Field HSSE Lead

Rob Shelton - General Manager Upstream - North

Steve Byatt - General Manager Gathering

Ken Larson – Upstream Projects Director Paul Hannan – Plant Supervisor

Reese Story – Area Operations Superintendent Jason Andrews – Area Operations Superintendent –(Windibri)

Claire Pattison - HSSE Performance Res & Co-ord

Anthony Harland – Pipeline Supervisor

Bryan Jenner – Plant Supervisor Scott Taylor – Gathering Supervisor

Tony Maiore – Maintenance Supervisor Neville Hardwick - Production Supervisor CPS

Sarah Price – Field HSSE Advisor Nathan Allan - Production Engineer

Blake Gillespie - First Delivery Supervisor Freeth Graham – GTA Pipelines

Chad Pettitt – AusSafe Senior consultant Kelly Johnstone – AusSafe Senior consultant

Informed:

Enter name/position of those to receive the completed document

Responsible Person: Lynn O’Malley Principal HSSE Advisor, Upstream Operations

Accountable Person: Rod McPherson HSSE Manager, Upstream Operations

Endorser: Dan McCoy General Manager Operations

QGC Operations and Projects Personnel

QGC Corporate HSSE



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RACIE Terms

R Responsible: the person who actually produces the document

A Accountable: the person who has to answer for the success or failure of the quality and timeliness of the document

C Consulted: those who must be consulted before the document is published

I Informed: those who must be informed after the document is published

E Endorsed: the person who must approve the document before publication

Revision Record

Issue Date Reason for Issue Responsible Accountable

A 4.04.12 Issued for comment L O’Malley Rod McPherson

0 28.05.12 Issued as Final L O’Malley Rod McPherson



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APPENDIX B – DEFINITIONS AND REFERENCES

Definitions

In this document, the following definitions apply:

Term Meaning

Angle of repose The slope at which dumped or excavated material is naturally stable and does not fall away

Backfill Material used for refilling excavations

Barricade An object such as jersey kerb or plant capable of providing effective protection against traffic entering the work site. IMPORTANT: Barricade/Barriers <4.2m clear of traffic at 60kmph, <3.0m clear of traffic at <60kmph and <6.8m clear of traffic at 80kmph require design verification and signoff by the traffic engineer (check with local/state requirements)

Barrier A self-supporting structure or a self-supporting series of continuous solid barriers erected or placed to restrict the entry to a workplace

Batter or slope The angle of an excavation in relation to the horizontal

Battering The development of a sloped wall to an excavation to a predetermined angle.

Benching The development of stepped sides to an excavation to lessen the overall slope of the excavated walls to a predetermined angle

CAD Coordinator Person (engineer, senior surveyor etc) with the capability to access and use the current services model or equivalent process/system. This person can be assigned the responsibility to provide services information as identified in survey documentation, services drawings, as built construction drawings and provide overlay drawings such as service locations onto design drawings

Closed Sheeting A continuous frame with vertical or horizontal sheathing planks placed side by side to form a continuous retaining wall supported by other members of a support system used to secure the face of an excavation

Competent person A person who has acquired through training, qualification or experience the knowledge and skills to carry out the task test or inspect equipment. Generally 'competency' is assessed by QGC or a third party. Note: In relation to performing an inspection or other task for a control measure, means a person who has acquired, through training, qualifications or experience the knowledge and skills to do the task in a safe way, including knowledge of relevant Australian Standards, Industry Standards, Codes of Practice and other legislation.

Confined space An enclosed or partially enclosed space that is not intended or designed primarily for human occupancy, within which there is a risk of one or more of the following:

an oxygen concentration outside the safe oxygen range;

the potential to contain an airborne containment that may cause;

o impairment to senses

o loss of consciousness

o asphyxiation

o injury from fire or explosion

a stored free-flowing or a rising level of liquid potential that may cause suffocation or drowning by engulfment.



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Term Meaning

Construction Zone A defined location that has been formally identified with clearly defined boundaries in which the following activities may occur:

a Greenfield or Brownfield site with special cordoned off barriers and denoted safe for the purpose of the work to be done;

excavation, including the excavation or filling of trenches, ditches, shafts, wells, tunnels and pier holes, and the use of caissons and cofferdams;

building, including the construction (including the manufacturing of prefabricated elements of a building at the place of work concerned), alteration, renovation, repair, maintenance and demolition of all types of buildings; and

civil engineering, including the construction, structural alteration, repair, maintenance and demolition of, for example, gas wells, pipelines, ponds, compression plant, power stations, roads, bridges and tunnels, and works related to the provision of services such as communications, drainage, sewerage, water and energy supplies, etc.

Cover A steel plate or other suitable material capable of withstanding the loads that may be imposed upon it and of sufficient weight or secured to prevent unauthorised removal.

Dial before you dig (DBYD)

A free referral service for information on underground pipes and cables anywhere is Australia.

Disconnected service Applies to all services power/communications/gas/sewer-water/storm water, etc.)

A disconnected service is one which is rendered permanently out of service

These services are decommissioned, disconnected /cut off from the supply source with the intention that they are redundant – they are no longer part of the service owners’ operational network.

Earthmoving machinery

Operator controlled mobile plant used to excavate, load, transport, compact or spread earth, overburden, rubble, spoil, aggregate or similar material, but does not include a tractor or industrial lift truck

Excavation Work involving any penetration > 300 mm below the ground surface.

Exclusion Zone An area from which all persons are excluded during excavation work

Face An exposed sloping or vertical surface resulting from the excavation of material

Fence Continuous enclosure not less than 1800mm in height that prevents unauthorised access to the work area and of such strength to remain erect in position during all conditions

FOPS Acronym for ‘falling object protection system’ – A protective structure over an operating cabin of a vehicle designed to prevent object falling from above from entering the operator’s station-Often integrated with a ROPS cabin but may be installed as a stand-alone system

Geo-technical engineer

An engineer, whose qualifications are acceptable for membership in the Institution of Engineers Australia and who has qualifications and experience in soil stability, soil mechanics and excavations

Greenfield Zone A formally designated Zone that has been clearly identified, fully risk assessed, and has been demonstrated to have limited operating infrastructure, live services or above or below ground, prior to new work being undertaken.

Handrail A rail one meter in height (plus or minus 100mm) effectively supported, security and of such rigidity and strength capable of providing support so as to prevent persons falling



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Term Meaning

Isolated Service Applies to all services power/ communications/ gas/ sewer-water/ storm water etc.

An isolated service is one, which is rendered temporarily out of service. I.e. electrical services power outage/water supply cut off – stop valves closed/ sewer mains plugged etc.

Services are isolated for one of two purposes:

o To enable work to be carried out in close proximity to the service in safety or to minimise risk of electrocution/explosion/fire/fluid leakage if the service is inadvertently damaged during work activities; or

o To enable work on the service (cut tee into water main, install sewer junction, CCTV camera inspection, connect power to switch gear etc) to be undertaken safely and in such a manner that temporary disruption of supply to consumers/public is controlled

Job Safety and Environment Analysis (JSEA)

A component of QGC’s overall risk management process that occurs at the area of work immediately prior to commencement of the task under a PTW

A JSEA involves conducting a work party review of all relevant HSSE documentation associated with the task and capturing any additional hazards not already identified (e.g. in the, PTW, SOP or SWMS), assessing the risk/s and deciding on appropriate controls to reduce the risks

Limits of approach A table, modified to suit local requirements which specifies the minimum distance between the service and mechanical or hand excavation

Non destructive digging

A process of digging holes with the use of air and water whilst the debris is vacuumed and saved for back fill

Operator protective device

A roll-over protective structure (ROPS), falling object protective structure (FOPS), operator restraining device and seatbelt

Overburden Surface soil that must be displaced

Permit Holder A person deemed competent and approved by QGC to carry out the work specified on a PTW and to whom a PTW can be issued by the Permit Issuer

Permit Issuer A person deemed competent and approved by QGC to define the control measures to be implemented in establishing a safe work environment for the Work Party and issue PTW and supporting documents

Positive identification Measures have been undertaken to determine that the service located is actually the service it is believed to be:

Measures include pot holing - soft dig options including non destructive excavation methods and scanning /detection techniques

Potholing The use of a high pressure water and vacuum system to safely locate buried pipelines and cables

Powered mobile plant Plant that us provided with some form of self propulsion that is ordinarily under the direct control of an operator

Prescribed information

Information about an underground service, necessary to safely undertake excavation/trenching work at or near the service, including:

(a) The location of the service (b) The type of the service (c) The depth of the service (d) For an electrical service—whether the service is live; and (e) The restrictions to be followed in doing the work

Runners Any timbers, metal or sheet piling used to form the vertical members if an excavation support



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Term Meaning

Safe Slope The steepest slope at which an excavated face is stable against slips and slides, having regard to the qualities of the material in the face, the height of the face, the load above the face and the moisture conditions

Safe Work Method Statement (SWMS)

A work statement produced as part of the submission for a Permit to Work that:

identifies the work activity to be undertaken and the proposed steps in the job;

states the safety hazards and or associated risks for each step;

describes the control measures that will be applied to the work activity and the revised risk;

and includes a description of the equipment used in the work and the competencies of the workers.

Scafftag Propriety trade mark commonly used to refer to a system of tagging scaffolds or other equipment to visibly record inspections and status

Service authority The owner, controller or operator of an underground or overhead service-

For the purpose of this guideline an underground or overhead service includes electrical, water, sewage and drainage, gas, telecommunications, petrochemicals and hazardous substances

Must A mandatory term – no deviation is permitted without written approval from the Group Technical Authority.

Shoring The use of timber, steel or other structural material to provide effective and adequate temporary support to maintain the stability of the walls of the excavation

Soft dig Is a non-mechanical means to expose / identify the location of underground services by using wooden handled or other insulated implements, i.e. shovels, mattocks etc.-Non destructive excavation includes methods such as Vacuum techniques

Soldier Vertical upright timber or steel element used for supporting a trench wall

Strut or screw jack A timber or steel member usually horizontal in compression, resisting thrust or pressure from the face or faces of an excavation. Screw jack struts are adjustable

Support Structure A shoring system to maintain the stability of the walls and roof of an excavation and includes a trench shield

Tom Structural member used to hold soldiers against a trench wall or to press walers apart in a close sheeted trench

Trench An excavation where the maximum depth is greater than the width-

Generally developed temporarily for the placement or repair of pipes and services

Trench Shield A structure with two vertical side plates permanently braced apart by cross frames or struts designed to resist the pressure from the walls of a trench and capable of being moved as a unit

Vacuum truck A truck mounted, heavy duty industrial vacuum loader designed to pneumatically convey solids, liquids, sludge or slurry through suction lines typically 5-10 cm in diameter

Waling A horizontal beam supporting vertical timbers, runners or sheeting

Water scouring An erosion process resulting from the action of the flow of water

Zone of influence The volume of soil around an excavation, measured from the bottom level of the excavation, between the sides of the excavation and a line drawn at an angle from the horizontal. Generally, the zone of influence extends some 30 degrees from the horizontal for sands and 45 degrees for other material



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Acronyms and Abbreviations In this document, the following acronyms and abbreviations apply:

Acronym/Abbreviation Meaning

FOPS Falling object protection system

JSEA Job Safety and Environment Analysis

PTW Permit To Work

ROPS Roll over protective structure

SWMS Safe Work Method Statement

Referenced / Associated Documents

Ref. Document Number Title/Description

1. BGA-OPS-OS-0032 Excavation and Trenching

2. QCOPS-BX00-HSS-PCE-000001 Safe Access to High Voltage Electrical Apparatus Procedure

3. QCOPS-BX00-HSS-PCE-000005 Safe Work Method Statement Procedure

4. QCOPS-BX00-HSS-PCE-000003 Confined Space Entry Procedure

5. QCOPS-BX00-HSS-PCE-000004 Fall Prevention Procedure

6. QCOPS-BX00-HSS-PCE-000011 Safe Access to Low Voltage Electrical Apparatus Procedure

7. QCOPS-BX00-HSS-CER-000001 Confined Space Certificate

8. QCOPS-BX00-HSS-CER-000003 Excavation Certificate

9. QCOPS-BX00-HSS-FRM-000002 SWMS form

10. Queensland Workplace Health and Safety Act 2011

11. Queensland Workplace Health and Safety Regulation 2011

12. Electrical Safety Act 2002 and Electrical Safety Reg

2002

13. Code of Practice: Working near exposed live parts

14. WA Code of Practice - Excavation 2005



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Ref. Document Number Title/Description

15. AS 1345:1995 Identification of the contents of pipes, conduits and ducts

16. AS1657 Fixed platforms, walkways, stairways and ladders — Design, construction and installation

17. AS 1742.3: 2009 Manual of uniform traffic control devices Part 3: Traffic control for works on roads

18. AS 2885.3: 2001 Pipelines: Gas & Liquefied Petroleum Maintenance and Operation

19. AS/NZS 3012: 2010 Electrical installations – Construction and demolition sites (Section 2.7 Lighting and luminaries)

20. AS 2293.1: 2005

Emergency escape lighting and exit signs for buildings Part1: System design, installation and operation (Section 5 Design of emergency escape luminaire installation)

Note: at this date, Workplace Health and Safety Queensland nor Safe Work Australia have Codes of Practice for Excavation. The WA Code of Practice is the latest available from Australian workplace safety authorities.


QCOPS-BX00-HSS-PCE-000007 Revision 0 - May 2012

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APPENDIX C – CERTIFICATE


QCOPS-BX00-HSS-PCE-000007 Revision 0 - May 2012

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APPENDIX D – FEEDBACK FORM

FEEDBACK FORM

This form should be used to notify comment or suggestions for improvement, relating to any aspect of the document identified below. Please return the completed form by Email, to the Responsible identified in the associated RACIE matrix

Document title:

Excavation Procedure

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QCOPS-BX00-HSS-PCE-000007

Issue No:

Issue Date:

Comments by:

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Excavation & Trenching Procedure

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