ATTACHMENT 12.11 SAFETY CASE ATCO 2020‐24 PLAN
EIM # 95958545
PUBLIC 31 August 2018
GAS DISTRIBUTION SYSTEM SAFETY CASE
Document ID: TCO PL00005 Revision: 6 Date: 01/12/2017
Authorisation
Title Name Date
Owner Manager Technical Compliance Stuart Jobling 01/12/2017 General Manager Asset and Engineering Reviewer Stevan Green 01/12/2017 Innovation
Reviewer General Manager Operations Russell Godsall 01/12/2017
Reviewer General Manager Construction Russell James 01/12/2017
Approver President ATCO Gas Australia Pty Ltd Pat Donovan 01/12/2017
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Document History
Rev No Date Amended by Details of Amendment 0 19/07/2001 G. Lukies Issued for submission to EnergySafety. 1 29/07/2005 J. Kong Major amendment for resubmission to EnergySafety. Revised to incorporate EnergySafety comments and to reflect new Alinta 2 05/04/2007 S. de Grauw Asset Management structure (supersedes ANS-RPT-22002). Revised and restructured to incorporate EnergySafety comments and to 3 23/03/2011 J. Galey reflect internalised WAGN organisational structure. Revised to incorporate recommended revisions as defined in the Preliminary 4 13/07/2011 J. Galey Certificate audit report and conditions specified in EnergySafety’s approval. 5 13/10/2017 E Ee / Revision and restructure to reflect the new ownership by ATCO Gas S Jobling Australia and changes to; organisational structures; roles and responsibilities; procedural changes; document referencing; Kalgoorlie Odorant Facility; asset retirement; service regulators; marker tape, tracer wire and pipeline markers signs; risk framework; Section 4 Formal safety Assessment describes intermediate and higher risks and controls. 6 01/12/2017 E Ee / S Revised to incorporate EnergySafety comments Jobling
Distribution List
Title Name Type President ATCO Gas Australia Pty Ltd P. Donovan Paper copy Manager Technical Compliance S. Jobling Paper copy General Manager Operations R. Godsall Paper copy General Manager Asset and Engineering Innovation S. Green Paper copy General Manager Construction R. James Paper Copy J. Nordmann M. McCarthy M Marshall Supervisors, Regional Depots S. Howard Paper copy P. Najar A Buchanan M. Sheaf Director Energy Safety K. Bowron Paper copy ATCO Gas Australia employees with EIM access N / A Electronic via EIM Paper copy available at ATCO ATCO Gas Australia personnel without EIM access N / A Gas Australia depots
ATCO Gas Australia Pty Ltd Gate 1, 81 Prinsep Road, Jandakot WA 6164 PO Box 3006, Success WA 6964 Other products referred to in this document are registered trademarks of their respective companies, and may carry copyright notices. © Copyright ATCO Gas Australia Pty Ltd, 2017. All rights reserved
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GAS DISTRIBUTION SYSTEM SAFETY CASE
GAS DISTRIBUTION SYSTEM SAFETY CASE
ATCO Gas Australia Safety Case Corporate Endorsement
ATCO Gas Australia Pty Ltd , formerly known as WA Gas Networks Pty Ltd (WAGN) prepared a Gas Distribution System (GDS) Safety Case under the provisions of Part 4, Division 3 of the Gas Standards (Gas Supply and System Safety) Regulations 2000 (GSSS Regulations) made under the requirements of the Gas Standards Act 1972. The GDS covered by the Safety Case is as defined in Gas Distribution Licence 8 (GDL8) issued by the Economic Regulation Authority to ATCO Gas Australia under the Energy Coordination Act 1994. The ATCO Gas Australia GDS Safety Case was accepted to form the prime reference to meet safety and technical compliance of the ATCO GAS AUSTRALIA GDS by the Director of Energy Safety on 28 July 2011 under the provisions of Regulation 34 of the GSSS Regulations. The ATCO Gas Australia GDS Safety Case provides a road map for the systems ATCO GAS AUSTRALIA has put in place for the safe operation of the ATCO Gas Australia GDS, including those for design, construction, operation, maintenance, training and supervision to manage the risks arising from hazards that have been identified as having the potential to result in an incident on the ATCO Gas Australia GDS. The Safety Case also describes the risk management systems ATCO Gas Australia has put in place to continue to identify, assess and take action to treat risks throughout the life of the ATCO Gas Australia GDS. The measurement and reporting of compliance with the ATCO Gas Australia GDS Safety Case is to be managed in accordance with the Compliance Policy. It is therefore imperative that the ATCO Gas Australia GDS Safety Case be complied with at all times. I support the contents of the ATCO Gas Australia GDS Safety Case. As President and a director of the licensee of the network, ATCO Gas Australia Pty Ltd, the responsibilities called for by ATCO Gas Australia are accepted, in compliance with the requirements of the Regulator, the Department of Mines, Industry Regulation and Safety, EnergySafety.
Pat Donovan President & Director ATCO Gas Australia Pty Ltd (ABN 90 089 531 975) Level 12, 2 Mill Street, Perth, WA, 6000
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ATCO Gas Australia Gas Distribution System Safety Case Contact Details
Business Trading Name and Licensee: ATCO Gas Australia Pty Ltd ABN 90 089 531 975 Gate 1, 81 Prinsep Road JANDAKOT WA 6164
PO Box 3006 SUCCESS WA 6964
ATCO Gas Australia Safety Case contact: Manager Technical Compliance ATCO Gas Australia Gate 1, 81 Prinsep Road JANDAKOT WA 6164
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TABLE OF CONTENTS
1. INTRODUCTION ...... 15 1.1 LEGISLATIVE PRECEDENCE ...... 16 1.2 HISTORY OF THE SAFETY CASE ...... 16 1.3 STRUCTURE OF SAFETY CASE ...... 16 1.4 ACCOUNTABILITY AND RESPONSIBILITY ...... 17 1.5 PURPOSE OF THE SAFETY CASE ...... 17 1.6 SCOPE OF SAFETY CASE ...... 17 1.7 DISTRIBUTION AND DOCUMENT CONTROL ...... 18 1.8 SAFETY CASE REVISION ...... 18 1.9 RELATIONSHIP BETWEEN SAFETY CASE AND OTHER STATUTORY BODIES AND OBLIGATIONS ...... 19 1.10 DEFINITIONS ...... 20 1.10.1 Abbreviations ...... 20 1.10.2 Terms ...... 26 1.11 INTERPRETATION ...... 31 2. ATCO GAS AUSTRALIA FACILITY DESCRIPTION ...... 33 2.1 ATCO GAS AUSTRALIA GAS DISTRIBUTION SYSTEM (GDS) ...... 33 2.1.1 Goldfields-Esperance Supply Area (Kalgoorlie Distribution Network) ...... 36 2.1.2 Great Southern Supply Area (Albany Distribution Network) ...... 36 2.1.3 Coastal Supply Area ...... 36 2.2 ATCO GAS AUSTRALIA GDS ASSETS ...... 37 2.2.1 Pipelines ...... 37 2.2.2 Distribution Mains ...... 38 2.2.3 Services ...... 41 2.2.4 Pressure Regulation Facilities ...... 42 2.2.5 Metering Facilities ...... 43 2.2.6 Kalgoorlie Odorant Facility ...... 44 2.3 COMPOSITION OF THE ATCO GAS AUSTRALIA GDS ASSET CLASSES ...... 45 2.3.1 Pipeline, Mains and Service Components ...... 45 2.3.2 Pressure Regulation Components ...... 47 2.3.3 Metering Facility Components ...... 47 2.3.4 Odorant Facility Components ...... 48 2.4 SAFETY FEATURES AND SYSTEMS OF LISTED PARTS OF FACILITIES ...... 49 2.4.1 GDS Isolation ...... 49 2.4.2 Pressure Regulation and Overpressure Protection ...... 49 2.4.3 Corrosion Protection Design ...... 51 2.4.4 Electrical Isolation ...... 52 2.4.5 Hazardous Area Classifications ...... 55 2.4.6 System Monitoring ...... 55
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2.4.7 Danger Marker Tape and Tracer Wire ...... 56 2.4.8 Pipeline Marker Signs ...... 57 2.4.9 Physical Security and Impact Protection Measures ...... 57 2.4.10 Buried Pipe Key Physical Protection Mechanisms ...... 58 3. SAFETY MANAGEMENT SYSTEM (SMS) ...... 59 3.1 LEADERSHIP AND COMMITMENT ...... 59 3.1.1 ATCO Gas Australia Corporate Reporting Structure ...... 59 3.1.2 Resources...... 61 3.1.3 Organisation and Responsibility ...... 73 3.2 EMPLOYEE INVOLVEMENT, CONSULTATION AND COMMUNICATION ...... 74 3.2.1 Pre-Start Meetings / Post Job Debriefs ...... 75 3.2.2 Safety Toolbox Meetings / Safety Focus Talks ...... 75 3.2.3 HSE Committee Meetings ...... 75 3.2.4 Safety and Environment Initiatives Plan (SEIP) Committee Meetings ...... 76 3.2.5 SafetyGrams, Toolbox Notes, EnviroGrams and Technical Notices ...... 76 3.2.6 Communication of Statistics ...... 76 3.3 INCIDENT REPORTING ...... 77 3.3.1 Incident Reporting and Investigation ...... 77 3.3.2 Action Tracking ...... 77 3.3.3 Communication ...... 77 3.4 OBJECTIVES AND KEY PERFORMANCE INDICATORS ...... 78 3.4.1 Objectives ...... 78 3.4.2 Key Performance Indicators (KPIs) ...... 78 3.4.3 Performance against KPIs ...... 78 3.5 RISK MANAGEMENT ...... 79 3.5.1 Risk Framework ...... 79 3.5.2 Corporate Risk Management ...... 81 3.5.3 Technical Compliance ...... 81 3.5.4 Formal Safety Assessment Development ...... 81 3.5.5 Safety Management Study ...... 82 3.5.6 Network FSA ...... 83 3.5.7 HAZOP ...... 83 3.5.8 Semi-Quantitative Risk Assessment ...... 83 3.5.9 Risk Treatment Action Tracking ...... 84 3.5.10 Health, Safety and Environment (HSE) ...... 85 3.5.11 AS 4645 Activity Risk Assessments ...... 85 3.5.12 Chemical Risk Assessments ...... 85 3.5.13 Job Risk Assessments ...... 85 3.5.14 Work under Permit to Work System ...... 86 3.5.15 Project Risk Management ...... 86 3.6 OPERATIONAL PROCEDURES ...... 87 3.6.1 Description ...... 87 3.6.2 Permit to Work System ...... 87 3.6.3 Procedures, and other relevant documents ...... 89
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3.6.4 Safe Work Instructions (SWI) ...... 89 3.7 EMPLOYEE SELECTION AND TRAINING ...... 91 3.7.1 Staffing Arrangements ...... 91 3.7.2 Employee Selection ...... 91 3.7.3 Training & Competencies ...... 92 3.8 ASSET MANAGEMENT SYSTEM ...... 93 3.8.1 Asset Management Planning ...... 94 3.8.2 Design Construction and Commissioning ...... 94 3.8.3 Operations and Maintenance Management ...... 99 3.8.4 Operating Parameters ...... 100 3.8.5 Asset Decommissioning/Retirement...... 101 3.9 OUTSOURCING ...... 101 3.9.1 Vendors ...... 101 3.9.2 Service Providers...... 102 3.10 GAS NETWORK INFORMATION SYSTEM (GNIS) ...... 104 3.11 THIRD PARTY DAMAGE PREVENTION ...... 105 3.11.1 Pipeline Marker Signs ...... 105 3.11.2 Dial Before You Dig ...... 105 3.11.3 HP Pipeline Location and Engineering Assessment ...... 106 3.11.4 Pipeline Patrol ...... 106 3.11.5 Awareness, Advertising and Training ...... 107 3.11.6 Land Owners / Occupier Liaison ...... 107 3.12 ATCO GAS AUSTRALIA INTERACTION WITH THIRD PARTIES ...... 108 3.12.1 Public Road Infrastructure ...... 108 3.13 MANAGEMENT OF CHANGE ...... 108 3.14 DOCUMENT CONTROL ...... 109 3.14.1 Revision Management ...... 109 3.14.2 Records Management ...... 110 3.15 INCIDENT AND EMERGENCY MANAGEMENT ...... 110 3.15.1 ATCO Gas Australia Emergency Response Management Plan ...... 110 3.15.2 GDS Isolation ...... 112 3.15.3 Pipeline Schematics ...... 112 3.15.4 Field Emergency Response Unit (FERU) ...... 113 3.15.5 Emergency Communications ...... 114 3.15.6 Incident Command Centre ...... 115 3.15.7 Emergency Services Cooperation ...... 115 3.15.8 Testing, Evaluation and Review ...... 116 3.15.9 Emergency Gas Supply Load Management ...... 116 3.16 LEAK MANAGEMENT ...... 116 3.16.1 Leakage Surveys and Leakage Detection ...... 117 3.16.2 Gas Leak Frequency Monitoring ...... 118 3.16.3 Asset Replacement ...... 119 3.16.4 Ventilation ...... 119
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3.17 ELECTRICAL HAZARD MITIGATION ...... 119 3.17.1 'Step’ and ‘Touch' Potentials ...... 119 3.17.2 Third Party Electrical Asset Review...... 120 3.18 GAS QUALITY AND CHARACTERISTICS ...... 120 3.18.1 Gas Quality Specifications ...... 120 3.18.2 Odorisation ...... 120 3.18.3 Gas Quality Monitoring...... 121 3.18.4 Natural Gas Composition and Properties ...... 123 3.18.5 LPG Composition and Properties ...... 124 3.18.6 Natural Gas and LP Gas Hazardous Properties ...... 126 3.18.7 Transportation of Alternative Fuel Gases ...... 126 3.19 LEGISLATION AND BUSINESS PRACTICES ...... 126 3.19.1 Changes to Legislation and Business Practices ...... 127 3.20 AUDIT AND INSPECTION ...... 127 3.20.1 Audit ...... 127 3.20.2 Inspection ...... 128 3.20.3 Action Tracking ...... 128 4. FORMAL SAFETY ASSESSMENT ...... 129 4.1 FORMAL SAFETY ASSESSMENT PROCESS ...... 129 4.2 SIGNIFICANT RISKS ...... 131 4.2.1 Loss of Containment due to physical damage ...... 131 4.2.2 Loss of Containment due to Material Failure ...... 132 4.2.3 Loss of Containment Due to Corrosion ...... 134 4.2.4 Loss of Containment in Perth CBD ...... 135 4.2.5 Loss of Containment in Multi-storey Buildings ...... 135 4.2.6 Loss of Containment in Multi-occupancy Dwelling ...... 136 4.2.7 Loss of Containment in High Risk Location ...... 137 4.2.8 Loss of containment from mains entering private property ...... 137 4.2.9 Loss of Containment in Buildings ...... 137 4.2.10 Loss of Containment in Albany LPG Network ...... 138 4.2.11 Loss of Containment from Unprotected Metallic Main ...... 139 4.2.12 Electric Shock ...... 139 4.2.13 M6WA domestic meter plug failure ...... 140 4.2.14 Gas Supply Interruption ...... 140 4.3 SIGNIFICANT CONTROLS ...... 142 4.4 IMPLEMENTATION OF ALTERNATIVE MEANS OF COMPLIANCE TO PROVISIONS OF AS/NZS 4645...... 150 4.4.1 Separation distances for services ...... 151 4.4.2 PE >DN200 ...... 151 4.4.3 Separation distances for Meter boxes ...... 152 4.4.4 Non-Standard Fittings ...... 152 5. REFERENCES ...... 154
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APPENDICES APPENDIX 1. ATCO GAS AUSTRALIA PTY LTD ORGANISATIONAL STRUCTURE ...... 165
TABLES Table 2-1: ATCO Gas Australia GDS sub-networks ...... 37 Table 2-2: ATCO Gas Australia GDS Pipeline construction breakdown ...... 38 Table 2-3: ATCO Gas Australia GDS Mains construction breakdown ...... 39 Table 2-4: ATCO Gas Australia GDS Service construction breakdown ...... 41 Table 2-5: Pressure Regulation Facilities ...... 42 Table 2-6: Metering Facilities ...... 44 Table 2-7 Types of Pressure Regulating Facilities...... 47 Table 2-8 Types of Gas Meters ...... 48 Table 3-2: ATCO Gas Australia depot and office locations and staffing levels ...... 61 Table 3-3: Key Position, or Group Responsibilities ...... 67 Table 3-4: KPI Performance reported monthly ...... 79 Table 3-5 – Qualitative frequency mapped to quantitative value ...... 84 Table 3-6: Process Area Procedures ...... 89 Table 3-7: Summary of ATCO Gas Australia SWI by general area or type of activity ...... 90 Table 3-8: Odorant, Odorant Mixtures ...... 121 Table 3-9: Periodic Sampling to Test Effectiveness of Odorisation ...... 122 Table 3-10: Natural Gas Monitoring Requirement (excluding Odorant) ...... 122 Table 3-11: ATCO Gas Australia LP Gas Quality Specification Compliance Testing (excluding Odorant) ...... 123 Table 3-12: Natural Gas Compositional Range ...... 123 Table 3-13: Natural Gas properties ...... 124 Table 3-14: LP Gas Compositional Range ...... 125 Table 3-15: LP Gas properties ...... 125 Table 4-1: Risk Register Asset Risk – Summary of Asset Types Assessed ...... 130 Table 4-2: Risk Register Activity Risks – Summary of Asset Types Assessed ...... 130 Table 4-3 Significant Risks and the relevant asset/activity ...... 131 Table 4-4: Factors considered in MRP tool to determine risk of asset (PE &PVC Mains ≤700kPa)133 Table 4-5: Significant Controls ...... 142 Table 4-6 Alternative Acceptable Means of Compliance to Provisions of AS/NZS 4645 ...... 150
FIGURES Figure 1-1: Relationship between ATCO Gas Australia GDS Safety Case and obligations to other statutory bodies ...... 19 Figure 2-1: ATCO Gas Australia GDS networks summary ...... 34 Figure 2-2: Gas distribution to consumer gas installation transition point ...... 35 Figure 3-1: Risk Management Process ...... 80 Figure 3-2: FSA Sources ...... 82
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1. INTRODUCTION ATCO Gas Australia Pty Ltd. owns and operates a Gas Distribution System (GDS) in the Coastal, Great Southern and Goldfields-Esperance gas supply areas. The GDS is defined in Gas Distribution Licence 8 (GDL8)[1], issued by the Economic Regulation Authority to ATCO Gas Australia Pty Ltd , under the Energy Coordination Act 1994[2]. The ATCO Gas Australia GDS consists of a number of discrete distribution networks transporting either natural gas (NG) from gas transmission pipelines, or liquefied petroleum gas (LPG) in the vapour state from the Albany LPG Storage Facility. The Gas Standards Act 1972 (the Act)[3] and Part 4, Division 3 of the Gas Standards (Gas Supply and System Safety) Regulations 2000 (GSSS Regulations)[4] provide for management of safety on a GDS via a Safety Case, and as a result the ATCO Gas Australia GDS Safety Case (referred to hereafter as the Safety Case) has been prepared under the provisions of this legislation. As per the requirements of regulation 31(1)(c) and (d) of the GSSS Regulations, the Safety Case is intended to adequately identify: • the measures necessary to “prevent hazardous events identified in the safety case from occurring”; • the measures necessary “to protect consumers, the public, employees, plant, equipment and the environment, should such events occur”; and • “The training and equipment requirements necessary for personnel to be able to implement the various procedures set out in it”. The Safety Case has been prepared to comply with the requirements of AS/NZS 4645.1: 2008 Gas Distribution Networks Part 1: Network Management[5] (AS 4645.1) and where the requirements of the following standards apply to the ATCO Gas Australia GDS, compliance to: • AS 2885.1: 2007 Pipelines – Gas and liquid petroleum Part 1: Design and construction[6] (AS 2885.1). • AS 2885.3: 2001 Pipelines – Gas and liquid petroleum Part 3: Operations and maintenance[7] (AS 2885.3). Section 2.3.7 of AS 4645.1 allows for alternative means of compliance to be documented and validated by independent competent personnel as resulting in an acceptable level of risk, providing it can be demonstrated that the risk control measures implemented result in an acceptable level of risk. Where aspects of the management of the gas distribution network are not in accordance with the means of compliance as identified in AS 4645.1, a formal safety assessment (FSA) shall be conducted to validate that the risk control measures implemented result in an acceptable level of risk. ATCO Gas Australia’s alternative means of compliance are defined in Section4.4. Where AS 4645.1 prescribes the risk control measures specified in AS/NZS 4645.2: 2008 Gas Distribution Networks Part 2: Steel pipe systems[8] (AS 4645.2), or AS/NZS 4645.3: 2008 Gas Distribution Networks Part 3: Plastic pipe systems[9] (AS 4645.3) as being a means of compliance to AS 4645.1, the controls specified in these standards shall be implemented, subject to documented and approved alternative means of compliance. Documented alternative means of compliance shall be validated by FSA to demonstrate risk control measures
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implemented result in an acceptable level of risk. ATCO Gas Australia’s alternative means of compliance are defined in Section 4.4.
1.1 Legislative Precedence (a) As defined in Regulation 20 of the GSSS Regulations, where compliance to the accepted Safety Case is demonstrated, this also demonstrates compliance to Regulations 18 of the GSSS Regulations.. (b) If there is a conflict between the accepted Safety Case and the Standards prescribed in the Safety Case, the obligations in the accepted Safety Case prevail.
1.2 History of the Safety Case In compliance with the requirements of this legislation, the WA Gas Networks WAGN Gas Distribution System Safety Case (GD PL 0130)[10] and the WA GAS Networks WAGN GDS Safety Case Implementation Plan (GD PL 0130 WI 01) (the SCIP)[11] were prepared and submitted by WA Gas Networks Pty Ltd (WAGN) (the previous GDL8 registered licensee) on 15 July 2011[12], and pursuant to Regulation (34)(1) of the GSSS Regulations, were accepted by the Director of Energy Safety (DES) on 28 July 2011[13]. The WAGN GDS Safety Case was accepted to form the prime reference to meet safety and technical compliance of the WAGN GDS. Therefore, the accepted Safety Case must be complied with at all times by employees and contractors when working on the Gas Distribution System in accordance with the ATCO Gas Australia Compliance Policy (REG PO00001)[14]. ATCO Gas Australia notified the DES 21 January 2013 in accordance with Regulation 35(2) and 35(3) of the GSSS Regulations that the implementation date for the WAGN GDS Safety Case was 28 January 2013. ATCO Gas Australia prepared a SCIP Close Out Report (TCO RP 0170)[15] to support the notification of the implementation date. In accordance with Regulation 36 of the GSSS Regulations the duration of the accepted WAGN GDS Safety Case is for the period of 5 years beginning 28 January 2013. On 29 July 2011, Canadian Utilities, an ATCO company, fully acquired the shares in WAGN from DUET (DUET) and WestNet Infrastructure Group (WNG)[16], and on 1 August 2011, WAGN began trading as ATCO Gas Australia. On 3 January 2012, WAGN (trading as ATCO Gas Australia) changed its name to ATCO Gas Australia Pty Ltd. The WAGN Australian Company Number (ACN) and Australian Business Number (ABN) were retained by ATCO Gas Australia Pty Ltd.[17]. The change in name of the licensee from WA Gas Networks Pty Ltd to ATCO Gas Australia Pty Ltd, together with changes in organisational structure prompted ATCO Gas Australia to rebadge and review the accepted safety case, WA Gas Networks WAGN Gas Distribution System Safety Case (GD PL 0130), Revision 4.0.
1.3 Structure of Safety Case Section 2.4 (Safety and Operating Plan) of AS 4645.1 defines the basis for the contents and structure of a gas distribution network safety case. The contents of the Safety Case complies with section 2.4 of AS 4645.1, however its structure deviates slightly from that documented in section 2.4. Since the ATCO Gas Australia GDS is a mature gas distribution network and hence FSAs are being conducted retrospectively for the majority of the network, the Formal Safety Assessment section is the last section of the Safety Case, following Section 3 (Safety Management System) rather than preceding it as suggested in AS 4645.1. For new additions to
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the ATCO Gas Australia GDS FSAs shall be conducted throughout the assets’ life cycle, commencing at the design phase, to ensure controls required to mitigate risk are documented within the Safety Case or referenced in ATCO Gas Australia documents and are identified in the FSA.
1.4 Accountability and Responsibility As the ATCO Gas Australia GDS network operator, and in compliance with of Part 4, Division 1 of the GSSS Regulations, ATCO Gas Australia is responsible and accountable for taking appropriate steps to: • “… ensure that each Prescribed Activity is, so far as is reasonable and practicable, carried out in such a way as to – (a) provide for the safety of persons; and (b) avoid or minimise any damage to property, inconvenience, or other detriment as a result of the activity.” In addition, ATCO Gas Australia seeks to ensure that each Prescribed Activity undertaken by ATCO Gas Australia personnel in relation to the ATCO Gas Australia GDS is in accordance with the other relevant provisions of the GSSS Regulations and compliance with the Safety Case. ATCO Gas Australia manages its compliance with these obligations by using the Safety Management System (SMS)[258] further described in Section 3, and other measures identified as a result of FSA referred to in Sections 2 and 4.
1.5 Purpose of the Safety Case The Safety Case provides a road map identifying the systems ATCO Gas Australia has in place to manage the safe operation of the ATCO Gas Australia GDS, including those for design, construction, operation, maintenance, training and supervision and for management of the risks arising from hazards that have been identified as having the potential to result in an incident on the ATCO Gas Australia GDS. The Safety Case also describes the risk management systems ATCO Gas Australia has put in place to continue to identify, assess and take necessary action to treat risks throughout the life of the ATCO Gas Australia GDS. ATCO Gas Australia employs a SMS (further described in Section 3) for managing work on the ATCO Gas Australia GDS. The SMS provides personnel at all levels of the organisation with direction for Prescribed Activities involving the ATCO Gas Australia GDS so that they may be conducted safely and in accordance with the provisions of the relevant systems, and to manage risks associated with these activities to As Low As Reasonably Practicable (ALARP).
1.6 Scope of Safety Case The Safety Case applies to the ATCO Gas Australia GDS as defined in GDL8 which excludes the following: • pipeline operations associated with the section of the Mandurah Gas Lateral (MGL) as defined in Petroleum Pipeline Licence 83 (PL83)[18] issued to ATCO Gas Australia under the Petroleum Pipelines Act 1969[19]. The ATCO Gas Australia Mandurah Gas Lateral (PL83) Safety Case (TCO PL00006[20] manages the safety systems associated with these ATCO Gas Australia assets, and includes ATCO Gas Australia Class 600 gas transmission High Pressure (HP) pipeline 120 (HP120), the facilities at North Dandalup
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and the pressure reduction station (PRS) 015 (PRS015) at Nambeelup, east of Mandurah; and • activities associated with the management of the Albany LPG Storage Facility under Dangerous Goods Licence DGS014467[21]: the safety systems for this facility are managed through ATCO Gas Australia’s systems and procedures pursuant to the Dangerous Goods Safety (Storage and Handling of Non-explosives) Regulations 2007[22] and the Dangerous Goods Safety Act 2004[23].
1.7 Distribution and Document Control The Safety Case is accessible, to ATCO Gas Australia personnel requiring access, within the electronic Document Management System (DMS) used by ATCO Gas Australia. ATCO Gas Australia employees and contractors, who do not have access to DMS are able to request access, via their supervisor or contract manager, to one of the hard copies of the Safety Case available at the depot at which they are based or allocated work from. The Safety Case availability is as per the Distribution List on page 3. Document Control Procedure (QLT PR0001)[24] is used to control revisions to ‘controlled documents’ within ATCO Gas Australia including those referenced in this Safety Case. Pages of each controlled copy contain the revision number and date. Copies without this information are to be regarded as uncontrolled.
1.8 Safety Case Revision The Safety Case will be revised, and amended if required, in accordance with the requirements of regulation 39 and 40 of the GSSS Regulations. At the date of the Safety Case, ATCO Gas Australia’s triggers for a revision include: • significant new or increased risk to safety or health arises or is likely to arise from the ATCO Gas Australia GDS which is not provided for in the Safety Case; • significant change(s) of circumstances, operations or management of the GDS; • direction by the Director of Energy Safety (DES) under regulation 40 of the GSSS Regulations; or • every 5 years.
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1.9 Relationship between Safety Case and other Statutory Bodies and Obligations The relationship between the ATCO Gas Australia GDS Safety Case and obligations to other statutory bodies is shown in Figure 1-1.
State Government of Western Australia
Economic Public Department of Mines, Regulatory Regulation Regulatory Utilities Industry Regulation and BodyBody Authority Office (PUO) Safety (DMIRS) (ERA)
Resources Safety Division Energy Safety Division Division Division Dangerous Goods and Petroleum Safety Branches
Energy Energy Operators Gas Standards Act Petroleum Pipelines Dangerous Goods Statutory Act Coordination Act Statutory Act (Powers) Act 1979 1972 Act 1969 Safety Act 2004 1974
Dangerous Goods Gas Distribution Pipelines Licence Licence Site Licence Licence Licence GDL8 PL83 DGS014467
Gas Distribution System – Network ATCOATCO GasGas • Coastal Supply Area Mandurah Gas Lateral AustraliaAustralia • • ApplicableApplicable Goldfields-Esperance Supply Area Class 600 Pipeline Albany LPG Storage AssetAsset (Kalgoorlie Network) HP120 Facility • Great Southern Supply Area (Albany • Class 600 PRS015 Network)
Gas Distribution Mandurah Gas PL83 Operational SelfSelf RegulationRegulation System Safety Case Lateral Safety Case Environmental Plan TCO PL00005 TCO PL00006 HSE PL00003
Asset and Emergency Operational Asset and Asset Business & HSEQ Safety Standards & Response Environmental Safety Management Asset Class Plans Management Management Codes of Practice Management Management Management Plan AST PL00018 System SystemsSystems Plan TCO PL00001 Plan HSE PL00001
Plans, Procedures, Work Instructions, Safe Work Instructions, Forms, Technical Specifications, Technical Notes, Services Agreements, Reports, Audits
Figure 1-1: Relationship between ATCO Gas Australia GDS Safety Case and obligations to other statutory bodies
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1.10 Definitions
1.10.1 Abbreviations
AA ATCO Australia
ABN Australian Business Number
AC Approved Criteria
ACN Australian Company Number
Albany MP Albany Medium Pressure Means the Albany Medium Pressure distribution Mains with current operating pressures between 8 and 20 kPa.
AIRS Automated Information Referral System
ALARP As Low As Reasonably Practicable – when the cost of further risk reduction measures becomes grossly disproportionate to the benefit gained from the reduced risk that would result.
AMP Asset Management Plan
AMS Asset Management System
ANSI American National Standards Institute
APA APA Group, the owner and operator of the Parmelia and Goldfields Gas Transmission pipelines.
API American Petroleum Institute
AS Australian Standard
°C Degrees Celsius
CA Corrective Action
CAD Computer Aided Design
CBD Central Business District
CHP City High Pressure Means the City High Pressure distribution Mains feeding the Perth CBD, West & East Perth, Northbridge and Highgate areas with current operating pressures between 160 and 200 kPa. CI Cast Iron
CP Cathodic Protection
DBNGP Dampier to Bunbury Natural Gas Pipeline
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DBP Dampier Bunbury Pipeline (the owner and operator of the DBNGP)
DBYD Dial Before You Dig Means the free national community service designed to prevent damage and disruption to the pipe and cable networks which provide Australia with the essential services such as electricity, gas, communications and water.
DES Director of Energy Safety Means the Director of Energy Safety referred to in the definitions of the Gas Standards Act 1972, and section 5 of the Energy Coordination Act 1994.
DFES Department of Fire and Emergency Services (of Western Australia)
DMS Document Management System
DN Nominal Diameter of Pipe
DUET DUET Group, previous joint owner of shares in WAGN
EIM Enterprise Information Management system, being the current document management system (DMS) used by ATCO Gas Australia
EIP External Interference Protection.
EMC ATCO Australia POS Executive Management Committee
EMT Emergency Management Team;
ERP Enterprise Resource Planning
ESNO Essential Services Network Operators group - formal mutual assistance agreement between signatories to provide assistance to other signatories in emergency incidents that are affecting their operation or infrastructure. Replaced LifeLines Mutual Assistance group on 28 October 2013, as outlined in the ATCO Gas Australia Work Instruction ESNO Communications (CTR PR0002 WI002)[25]).
ESNORG Essential Services Network Operators Reference Group - works to ensure cooperation between network operators and for the sharing of resources and emergency equipment when necessary.
FERU Field Emergency Response Unit
FSA Formal Safety Assessment Means the various types of formal risk assessment techniques such as, HAZOP Studies, HAZID Studies, AS 2885 Risk Assessments, Quantitative Risk Assessments. Exception: for the title of Section 4 of this document ‘Formal Safety Assessment’ refers to the formal safety assessment described within the GSSS Regulations, which includes specific reference to “gas incident”(s).
GDL8 Gas Distribution Licence 8 and means the distribution licence issued to ATCO Gas Australia by the Coordinator of Energy under the Energy Coordination Act 1994.
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GDS Gas Distribution System and has the same meaning distribution systems as defined within Section 3 of the Energy Coordination Act 1994 and GDL8 as follows: 1. a system of gas pipelines, Mains, and Service pipes, designed to operate at a pressure of less than 1.9MPa, for the transportation of gas to customers; or 2. any other part of the gas distribution system (as defined in section 90 of the Gas Corporation Act 1994 [26] repealed by section 93 of the Gas Corporation (Business Disposal) Act 1999)[27]) at the time when a distribution licence is first issued for all or any part of that system (regardless of the pressure at which it is designed to operate), and any associated apparatus, facilities, structures, plant, or equipment. GEPC Gas Emergency Planning Committee - responsible for non-operational strategy relating to gas supply issues in Western Australia. GGP Goldfields Gas Pipeline (also known as the Goldfields Gas Transmission (GGT) pipeline). GI Galvanised Iron
GNIS The Gas Network Information System used by ATCO Gas Australia to record the approximate location of ATCO Gas Australia gas infrastructure, which includes pipes conveying gas, PRSs, isolating valves, Regulator Sets, Meter Sets, meters and pipe protection systems. GP General Partnership – forms part of the name of ATCO Gas Australia: ATCO Gas Australia GP Pty Ltd. GPS Global Positioning System
GSSS Regulations Gas Standards (Gas Supply and System Safety) Regulations 2000
HAZID Hazard Identification Study Means an ATCO Gas Australia Hazard Identification Study
HAZOP Hazard and Operability Study Means an ATCO Gas Australia Hazard and Operability Study
HHV Higher Heating Value
HP High Pressure Refers to ATCO Gas Australia GDS pipelines that operate above 500 kPa pressure.
HSE Health, Safety and Environment and also refers to the ATCO Gas Australia HSE team
HSEQ Health, Safety, Environment and Quality
HSSE Health, Safety, Security & Environment
IBIS Infrastructure Browser Information System - the application used by ATCO Gas Australia to browse the Gas Network Information System (GNIS) that interfaces to ERP (Enterprise Resource Planning), DBYD, NDV and DMS. IBIS was commissioned by ATCO Gas Australia on 26 May 2014 to replace AssetView.
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ICCP Impressed Current Cathodic Protection
IPM Isopropyl Mercaptan
IMT Incident Management Team
ISO International Organization for Standardization
ITP Inspection and Test Plan
JRA Job Risk Assessment Means the process where hazards associated with each step of a job are identified, the risk is assessed and control measures are put in place to minimise the risk to personnel, property and environment. km kilometre
KP Kilometre Point kPa (absolute) Kilopascals absolute (pressure) kPa Kilopascals gauge (pressure)
KPI Key Performance Indicator
LOC Loss of Containment
LPG Liquefied Petroleum Gas
LP Gas LPG reticulated in its vapour (or gases) phase throughout a distribution network m metre(s)
MAOP Maximum Allowable Operating Pressure
For pipelines subject to the requirements of AS 2885 Means the Maximum Allowable Operating Pressure as defined in AS 2885: “The maximum pressure at which a pipeline or section of a pipeline may be operated, following hydrostatic testing in accordance with this Standard.” For pipelines subject to the requirements of AS 4545 Means the Maximum Allowable Operating Pressure as defined in AS 4645: “The maximum pressure at which a gas network or any element of the network may be operated in accordance with the provisions of this Standard. NOTE: Plastics material standards may use a different definition.”
MGL Mandurah Gas Lateral - as defined in Pipeline Licence PL83: comprising HP120, the Pigging Facilities and PRS015.
MJ Mega joules – energy measurement unit
MOC Management of Change
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mm millimetres
MPa (absolute) Megapascals absolute (pressure) – pressure measurement unit
MRP Mains Replacement Prioritisation, as it refers to the DNV GL Software of the same name
NOHSC National Occupational Health and Safety Commission
NZS New Zealand Standard
OD Outside Diameter
OHS Occupational Health and Safety
OPSO Over-Pressure Shut-Off valves/devices also referred to as Slam Shut valves/devices
ORMCC Operational Risk Management and Compliance Committee pa Per annum
PE Polyethylene
PE80 Medium Density Polyethylene
PE100 High Density Polyethylene
PL83 Pipeline Licence 83 (Mandurah Gas Lateral)
PM Preventive Maintenance
PMD Pressure Monitoring Device
PMP Project Management Plan
POS Principal Operating Subsidiary.
PPE Personal Protective Equipment
PRS Pressure Reduction Station psi Pounds per square inch (6.89 kPa)
PVC Polyvinyl Chloride
RACI Chart ATCO Gas Australia RACI Chart (TCO RG0001)[28]. RACI: Responsibility, Accountability, Consultation and Information.
RCM Reliability Centred Maintenance
RMAP Risk Management Action Plan
SAIDI System Average Interruption Duration Index
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SAIFI System Average Interruption Frequency Index
SCIP WAGN GDS Safety Case Implementation Plan (WAGN GD PL 0130 WI 01) scm Standard cubic metre
SDR Standard Dimension Ratio - used by polyethylene pipe manufacturers as a method of rating pressure piping. SDR is a ratio of pipe outside diameter to wall thickness and can be expressed as SDR = outside pipe diameter / pipe wall thickness.
SEIP Safety and Environment Initiative Plan
SMS Safety Management System
SWI Safe Work Instruction
TBM Tertiary Butyl Mercaptan
THT Tetrahydrothiophene
TJ Terajoules (energy)
TRU Transformer Rectifier Unit
UAFG Un-Accounted For Gas uPVC Unplasticised Poly-vinyl Chloride
WA Western Australia
WAGN WA Gas Networks Pty Ltd, previous registered title holder of licence GDL 8
WNG WestNet Infrastructure Group Ltd, previous joint owner of shares in WAGN
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1.10.2 Terms
the Act Gas Standards Act 1972 AC Classified Hazardous A substance that is determined to be a hazardous substance under regulation Substance 5.3(3) of the Occupational Safety and Health Regulations 1996[29]. The acronym ‘AC’ is derived from the ‘Approved Criteria’ outlined in the document Approved Criteria for Classifying Hazardous Substances [3rd Edition: NOHSC: 1008(2004)[30], published by the National Occupational Health and Safety Commission. Access Arrangement Means the Access Arrangement for the ATCO Gas Australia Gas Distribution Systems prepared pursuant to the National Gas Access (WA) Act 2009 [31]), which amends and implements the National Gas Law[32] in Western Australia. ATCO Gas Australia ATCO Gas Australia Pty Ltd - replaced WA Gas Networks (WAGN) as the registered titleholder of Gas Distribution Licence GDL 8 (GDL8) on 1 August 2011 ATCO Gas Australia Includes documents, processes and procedures developed for operation of documents, procedures, the ATCO Gas Australia GDS. work practices & systems ATCO Gas Australia Does not have the same meaning as “employee” as defined in the GSSS employee Regulations, where ATCO Gas Australia is the operator of the ATCO Gas Australia GDS and for the purpose of this Safety Case means: A person employed directly by ATCO Gas Australia. ATCO Gas Australia Has the same meaning as “employee” as defined in the GSSS Regulations, personnel where ATCO Gas Australia is the network operator: “In relation to a network operator, means — (a) a person employed or engaged by the operator; (b) a contractor or subcontractor to the operator; or (c) a person employed or engaged by a person referred to in paragraph (b).” AS 2885 Australian Standard 2885 Pipelines – Gas and liquid petroleum Parts 0, 1, 2, 3, and 5
AS 2885.1 AS 2885 Part 1
AS 2885.3 AS 2885 Part 3
AS 4645 AS/NZS 4645 - Gas Distribution Networks Parts 1, 2 and 3
AS 4645.1 AS/NZS 4645.1: 2008 Gas Distribution Networks Part 1: Network Management
AS 4645.2 AS/NZS 4645.2: 2008 Gas Distribution Networks Part 2: Steel pipe systems
AS 4645.3 AS/NZS 4645.3: 2008 Gas Distribution Networks Part 3: Plastic pipe systems AS 2885 Risk Means a Safety Management Study as defined in AS 2885. Assessment Class 150 & 125 HP Sections of the ATCO Gas Australia GDS of steel construction designed with Pipeline a MAOP of between 700 and 1,920 kPa, operating at pressures below 1,920 kPa. Note, there are sections of steel pipe which were constructed to Class 125 standards, which due to age or interconnected network sections have a MAOP of 350 kPa.
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Class 300 HP Pipelines Sections of the ATCO Gas Australia GDS of steel construction designed with a MAOP of between 1,920 and 5,010 kPa, operating at pressures below 4,000 kPa. Class 600 HP Pipeline Sections of the ATCO Gas Australia GDS of steel construction designed with a MAOP of between 3,600 and 10,200 kPa. “Class” of HP Steel Used to prefix the pounds per square inch (psi) pressure rating of a HP Steel pipelines pipeline designed to be capable of transporting saturated steam at pressures up to the Class rating of the pipeline, e.g. Class 600 means up to 600 psi (4,137 kPa) and similarly Class 150 for 150 psi (1,034 kPa) etc. Combination Meter Box An enclosure constructed to contain a gas Meter Set in one compartment, and an electrical meter in a separate adjacent compartment. Confined Space As defined in the Occupational Safety and Health Act 1984[33], Occupational Safety and Health Regulations 1996, confined space means “an enclosed or partially enclosed space which — (a) is not intended or designed primarily as a workplace; (b) is at atmospheric pressure during occupancy; and (c) has restricted means for entry and exit, and which either — (d) has an atmosphere containing or likely to contain potentially harmful levels of contaminant; (e) has or is likely to have an unsafe oxygen level; or (f) is of a nature or is likely to be of a nature that could contribute to a person in the space being overwhelmed by an unsafe atmosphere or a contaminant”. Controlled document Controlled documents are ATCO Gas Australia documents, the content of which is controlled by a formal revision and approval process. They are considered point of reference documents which, through their lifecycle may be reviewed, revised and distributed several times, however not all documents fall in to this category. Information relating to which documents fall under the Controlled Document category is available in ATCO Gas Australia HSEQ Management System Overview (QLT MA00001)[34]. Control Room The ATCO Gas Australia Control Room currently located at the Jandakot depot EnergySafety EnergySafety a division of the Government of Western Australia Department of Mines, Industry Regulation and Safety Executive Management Means the members of ATCO Gas Australia who report directly to the President of ATCO Gas Australia. Foreign Structure Has the meaning it is given in AS 2832.1-2001 Cathodic Protection of Metals- Part 1: Pipes and Cables[35]. A buried or submerged structure that may be subject to interference arising from the cathodic protection of a primary structure Gas incident Means an incident or event in, on or associated with a distribution system, other than a notifiable incident that: • materially affects or is likely to materially affect the supply of gas: or • is caused by gas.
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Gate Station Also known as Meter Stations (when referred to as part of gas transmission system in Western Australia). The outlet point of these stations is the custody transfer point between upstream transmission and the downstream ATCO Gas Australia GDS. These stations typically include metering and, if required, pressure reduction from gas transmission to gas distribution. GHS Classified A substance that is determined to be a hazardous substance under regulation Hazardous Substance 5.3(4) of the Occupational Safety and Health Regulations 1996. The acronym ‘GHS’ is derived from the ‘Globally Harmonised System’ outlined in the document Globally Harmonized System of Classification and Labelling of Chemicals, 5th Revised Edition, 2013[36], published by the United Nations. Hazardous Area Has the meaning given in the Dangerous Goods Safety (Storage and Handling of Non-explosives) Regulations 2007. As at the date of this document, that meaning is “an area or space in which the atmosphere contains or may be reasonably expected to contain any material or substance (including combustible dusts, combustible fibres, flammable vapours, flammable liquids, flammable gases, flammable or combustible fumes) at a concentration that is capable of being ignited by an ignition source” Hazardous Materials Has the meaning given: 1. for the term dangerous goods as defined in regulation 8 of the Dangerous Goods Safety (Storage and Handling of Non-explosives) Regulations 2007; as at the date of this document; and 2. for the term hazardous substance as defined in regulation 5.1 and classified in accordance with regulations 5.3(3) and 5.3(4) of the Occupational Safety and Health Regulations 1996, as at the date of this document High Rise Building Refer to definition for Multi-storey Building and section 4.2.5.2, being a Multi- storey Building with purpose built internal GDS assets designed to assure risk is controlled to an acceptable level. High Risk Location Has the meaning as defined in AS4645.1: “Includes locations such as schools, hospitals, public gathering places and tunnels”. ATCO Gas Australia has included hospitals and schools as zoned by the Metropolitan Region Scheme. ATCO Gas Australia have a list of public gathering spaces deemed as a high risk locations based on capacity of the venues. City Centre Areas as defined by the MRS were also considered as High Risk Locations. Jandakot Depot Gate 1, 81 Prinsep Rd, Jandakot, Western Australia Landgate Western Australia Land Information Authority – formerly the Department of Land Information (DLI). Ltd Limited – forms part of the full name of ATCO Gas Australia: ATCO Gas Australia GP Pty Ltd. Main Has the meaning given in AS 4645.1 Gas distribution networks Part 1: Network management: A pipe installed to convey gas to individual Services or other distribution facilities.
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Major Activities Has the same meaning as defined in regulation 22(1) of the GSSS Regulations: Means any of the following kinds of Prescribed Activity — (a) construction of Pipelines having a diameter of 100 mm or more and a length of 100 metres or more; (b) construction of gas Mains having a diameter of 150 mm or more and a length of 300 metres or more; (c) construction of gate stations or PRSs for systems with MAOPs of 500 kPa or greater; (d) construction of district Regulator Sets fed from Pipelines. Major Discharge Means: the unplanned and uncontrolled release inside a building of 10 cubic metres or more of gas: or the unplanned and uncontrolled release in the open air of 1000 cubic metres or more of gas. Meter means a device used to measure the amount of gas passing through the device Meter Set Means the equipment and ancillaries, containing piping, electrical isolation for Cathodic Protection (CP) and step touch protection, isolation valve(s), Filtration, Pressure control devices, Meter, Flow computing, pressure and temperature alarming and telemetry.
Minister Is not defined in the Gas Standards Act 1972, or GSSS Regulations and therefore has the meaning as defined in Section 12 of the Interpretation Act 1984[37]: “(a) in the case of a reference in an Act, as a reference to the Minister of the Crown to whom the administration of the Act, or the provision of the Act, in which or in respect of which the term is used, is for the time being committed by the Governor; and (b) in the case of a reference in subsidiary legislation, as a reference to the Minister of the Crown to whom the administration of the Act, or the provision of the Act, under which the subsidiary legislation is made, is for the time being committed by the Governor; and (c) so as to include a Minister of the Crown for the time being acting for or on behalf of the Minister referred to in paragraph (a) or (b), as the case may require.” Multi-storey Building Refers to a residential building 3 or more storeys where there is 5 or more gas meters and at least 1 gas meter located internally. Multi-occupancy Dwelling Refers to a dwelling with 2 storeys where there are 5 or more gas meters and at least 1 gas meter located internally. Network operator Has the same meaning as defined in the GSSS Regulations: “(a) means an undertaker who operates a distribution system; and (b) in relation to a Prescribed Activity for the purposes of a distribution system, includes any contractor, and any subcontractor, to the system’s network operator who is contracted to carry out the Prescribed Activity”.
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Notifiable Incidents Has the meaning as defined in the regulation 43(1) of the GSSS Regulations: “(1) A network operator must notify the Director of — (a) any fire, explosion, or major discharge of flammable gas, in, on or from the distribution system; (b) any incident or event that is caused, or significantly contributed to, by gas and that results in — (i) serious injury; or (ii) serious damage; or (c) any unplanned interruption to the supply of gas from the distribution system to — (i) any consumer whose annual gas consumption usually exceeds, or can reasonably be expected to exceed, 50 terajoules; or (ii) at least 100 other consumers.” Operation Operation in relation to ATCO Gas Australia GDS includes constructions, operations, maintenance and emergency management. Permit System Refers to: • the procedure ATCO Gas Australia Permit to Work System (TCO PR0007)[38]; • the system that is used by ATCO Gas Australia for controlling specified work as described in the procedure Permit to Work System (TCO PR0007); and • the permit required to enter a confined space as described in the work instruction ATCO Gas Australia Confined Space Entry (TCO PR0007 WI001)[39]. Pipeline a Main or Service that conveys gas to other distribution facilities and having a MAOP of 500 kPa or greater Prescribed Activity Is as defined in the GSSS Regulations and means “anything related to the conveyance, control, supply or use of gas done by, for, or with the authority of, the network operator in the course of construction, maintenance, repair or operation of any part of a distribution system”. Prescribed pressure Has the meaning as defined in the GSSS Regulations: “prescribed pressure, in relation to — (a) a gas installation that uses or is to use tempered LPG, means 0.75 kPa (gauge); (b) a gas installation that uses or is to use natural gas or simulated natural gas, means 1.25 kPa (gauge); and (c) a gas installation that uses or is to use LPG, means 2.75 kPa (gauge)” Procedure A Procedure is an ACTO Gas Australia document which gives instruction for how to conduct work in the correct manner. Pty Proprietary – forms part of the name of ATCO Gas Australia: ATCO Gas Australia GP Pty Ltd. Regulator Set Means pressure regulating equipment and ancillaries, such as OPSO devices, in one location. Reportable Incident A Notifiable Incident which requires ATCO Gas Australia to investigate and report to the DES under regulation 44 of the GSSS Regulations.
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Safety Focus Talk A monthly forum intended to include some or all of the following as deemed required: • corporate feedback; • Event and Hazard reviews; • policy & procedure reviews; • a health and safety related presentation; and • an update for staff on ATCO Gas Australia HSE activities. SafetyGram An ATCO Gas Australia document to communicate and raise awareness of hazards, their associated risks and controls to be or already implemented. Safety Toolbox A monthly meeting intended to provide: • information to staff members regarding workplace related HSE issues; and • a forum to raise HSE issues. Safe Work Instruction An ATCO Gas Australia document that combines the instructions and information provided within a work instruction or procedure and the requirements for safe work method statements as referred to by regulation 3.143 of the Occupational Safety and Health Regulations 1996. Commonly referred to as ‘SWI’. Service A pipe that carries gas from a Main to one or more consumer meter assemblies or equivalent points of supply and has a maximum internal volume of 0.2m3. Significant Risk ‘Intermediate’, or ‘high’ risks assessed in accordance with ATCO Australia POS Risk Management Framework (AA-RSK-FWK-01) Technical Notice Technical Notices are issued to provide technical information about tools and equipment used within the business. These include, but are not limited to, tool improvements or modifications, tool recalls due to faults or new tooling available for use. Trilaminate A carbon steel pipe with 3 layer polyethylene coating, consisting of Fusion Bonded Epoxy, adhesive and PE100. Trunk Main An ATCO Gas Australia GDS Main which is the sole means of supplying gas to downstream gas distribution pipework and ancillaries, i.e. a Main which supplies to a part of the ATCO Gas Australia GDS which has a sole gas supply path through that Main and is not ‘back gassed’. Wobbe Index A measure of the amount of energy delivered to a burner via an injector. It is an indicator of the compatibility between the natural gas supplied and the burner. Gas appliances and burners are normally designed and certified to operate within a range of gas quality specifications. (Expressed in MJ/m3 of gas).
1.11 Interpretation In this document, unless the context otherwise requires: • words in the singular include the plural and vice versa; • any gender includes the other genders; • if a word or phrase is defined, its other grammatical forms have corresponding meanings;
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• “includes” means includes without limitation; • a reference to: − a policy, procedure, work instruction or other document of ATCO Gas Australia is a reference to that document as modified or replaced from time to time; − a person includes a partnership, joint venture, unincorporated association, corporation and a government or statutory body or authority; − person includes the person’s legal personal representatives, successors, assigns and persons substituted by novation; − this document includes appendices to it; and − headings do not affect the interpretation of this document.
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2. ATCO GAS AUSTRALIA FACILITY DESCRIPTION
2.1 ATCO Gas Australia Gas Distribution System (GDS) The ATCO Gas Australia GDS operates in the Coastal, Great Southern and Goldfields- Esperance gas supply areas under the conditions defined in GDL8. Reference maps which illustrate the extent of the ATCO Gas Australia GDS are available on ATCO Gas Australia’s website at http://www.atcogas.com.au/About-Us/Coverage-Maps. The ATCO Gas Australia GDS covers: • The Perth metropolitan area (including Barter Road, Ellenbrook, Mandurah and Rockingham); • Muchea, Eneabba and Geraldton, north of Perth; • Pinjarra, Harvey, Kemerton, Bunbury and Busselton, in the south west of the State; • Kalgoorlie-Boulder, in the Goldfields (the ‘Kalgoorlie Distribution Network’); and • A LP Gas distribution system in Albany (the ‘Albany Distribution Network’). Natural Gas is distributed through the ATCO Gas Australia GDS (excluding the Albany Distribution Network, where the gas is LP Gas) from the Dampier to Bunbury Natural Gas Pipeline (DBNGP), Parmelia gas transmission pipeline and Goldfields Gas Pipeline (GGP) via gate stations and Pressure Reduction Stations (PRSs), designed to limit pressures in the ATCO Gas Australia GDS to below the Maximum Allowable Operating Pressures (MAOPs) for each section of pipe. The Albany Distribution Network is simply configured; a PRS installed immediately downstream of the Albany LPG storage facility, lowers pressure and this gas is then reticulated throughout the downstream Gas Distribution System (GDS). The GDS in each of these areas are made up of various asset classes described in Section 2.2. These components are used to transport, control the pressure of, monitor system parameters and measure the delivery of Natural Gas or LP Gas to consumers. There are currently 17 PRSs, and 197 Regulator Sets operating with inlet pressures of greater than 350 kPa and 355 Medium Pressure (MP) Regulator Sets operating with inlet pressures 350 kPa or less used to control the pressure in the ATCO Gas Australia GDS. Customer Meter Sets are intended to provide final pressure reduction to meet agreed individual customer requirements or otherwise to meet the requirements for “prescribed pressure” as defined in the GSSS Regulations. ATCO Gas Australia GDS operating pressure are summarised in Figure 2-1.
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Gate Station (Owned Coastal Supply Area by Others) Lateral with MAOP 3,600–6,900 kPa (Class 600/300 High Pressure Pipeline with MAOP 1,900 kPa (HP) Steel) (Class 150 HP Steel) G PRS R M
MAOP 500 – 700 kPa (HP Polyethylene (HP PE) SDR11) R M R R M
MAOP 100 kPa Lateral with MAOP 3,600 – 6,900 kPa R R M (Class 600/300 HP Steel) G PRS MAOP 7 kPa MAOP 350 kPa R R M (Polyethylene High Pressure (PEHP)) R M *
Pipeline with MAOP 1,900 kPa MAOP 700 kPa (Class 150 HP Steel) (Fremantle High Pressure (FHP)) G PRS R R M
* MAOP 350 kPa (PEHP) R R M
MAOP 350 kPa (City High Pressure (CHP)) R R M
Pipeline with MAOP 1,900 kPa MAOP 350 kPa (Class 150 HP Steel) (PEHP) G R R M
DBNGP or Parmelia Custody Transfer Line Pipeline
Distribution Pipe APA to ATCO Gas Goldfields-Esperance Supply Area GGP – Compound MAOP 10,200 kPa (Kalgoorlie Distribution Network) (Class 600 High Pressure (HP) Steel) Parkeston G R M Lateral MAOP 350 kPa (PEHP)
The Albany Plant Great Southern Supply Area (Albany Distribution Network) LPG R P PRS MAOP 20 kPa M (Albany)
Figure 2-1: ATCO Gas Australia GDS networks summary
Legend: PRS = Pressure Reduction Station R = Regulator M = Meter P = Plant G = Gate Station
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Refer to Codes and Practices (Site Workplace Specific Legislation affecting Gas Distribution (TCO PL00005 RF01)[262] for a summary of legislation and codes of practices applicable to gas distribution operations and details of the gas distribution to consumer gas installation transition point, being the outlet of the meter bend as shown in Figure 2-2.
Figure 2-2: Gas distribution to consumer gas installation transition point
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2.1.1 Goldfields-Esperance Supply Area (Kalgoorlie Distribution Network) The Southern Cross Pipelines (NPL) Australia Pty Ltd (an APA Group company) owned and operated GGP and Parkeston Lateral (Petroleum Pipeline Licence PL28) to Parkeston Power Station supplies Natural Gas to ATCO Gas Australia’s stand-alone Kalgoorlie Distribution Network via the Kalgoorlie Gate Station. Here Natural Gas is metered and the pressure controlled, before distribution into the Kalgoorlie Distribution Network which supplies gas to more than 7,000 customers. The Kalgoorlie distribution network nominally operates at 280kPa, and consists of Medium Density Polyethylene (MDPE) PE80 SDR17 mains including approximately 9km of 160mm diameter header mains and a further 168km of 110mm and 40mm diameter reticulation mains. The custody transfer point for the Kalgoorlie Distribution Network is immediately downstream of the flange of Main Line Valve 6050 of the Parkeston Lateral at which point ATCO Gas Australia is responsible for the safety systems. It is noted that this valve is located within the transmission operator’s compound as well as 8m of DN50 pipe. An odorant injection facility was installed and commissioned in September 2014 to ensure Natural Gas in the Kalgoorlie Distribution Network is odorised in accordance with Regulations 5(2)(e), 6 and Schedule 1 of the GSSS Regulations.
2.1.2 Great Southern Supply Area (Albany Distribution Network) The Albany region is supplied with LP Gas via the Albany Distribution Network, fed by the Albany LPG Storage Facility which currently has six (6) active and two (2) inactive, 45 kilolitres LPG storage tanks. The Albany Distribution Network feeds the Albany area via a PRS operating at a set point of 8 kPa through approximately 163 km of Mains ranging from 40 - 200 mm diameter of predominantly unplasticised Poly Vinyl-Chloride (uPVC) and PE (PE80 and PE100) construction. The project to remove galvanised iron and metallic Mains within the Albany Distribution Network and replace with PE100 was completed in 2014/2015. The Albany Distribution is a stand-alone network and commences at the inlet isolation valve (HV60) of PRS013 at the Albany LPG Storage Facility and supplies gas to more than 7,000 customers. ATCO Gas Australia owns and operates the LPG Facility (including the land) in its entirety; LPG is supplied to the Albany LPG Storage Facility via road tanker.
2.1.3 Coastal Supply Area Natural Gas from the DBNGP (Petroleum Pipeline Licence PL40) and the Parmelia (Petroleum Pipeline Licence PL1) gas transmission pipeline are metered through gate stations owned and operated by DBP and APA, respectively. The custody transfer points mark the commencement of the ATCO Gas Australia GDS and ATCO Gas Australia assumes responsibility for safety of its downstream distribution systems. The ATCO Gas Australia GDS distributes Natural Gas to supply domestic, commercial and industrial consumers, throughout the Perth metropolitan area and various country centres. The Coastal Supply area also covers a number of discrete sub-networks, extending from Geraldton in the north, to Busselton in the south as listed in Table 2-1, and supplies gas to more than 740,000 customers. These sub-networks are not necessarily continuous or interconnected but each is associated with at least one Physical Gate Point marking the boundary between the ATCO Gas Australia GDS and either the DBNGP or Parmelia gas transmission pipeline.
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Table 2-1: ATCO Gas Australia GDS sub-networks
Metropolitan Sub-networks Non-Metropolitan Sub-networks
• Ellenbrook • Geraldton • North Metropolitan • Eneabba • South Metropolitan • Muchea • Barter Road • Pinjarra • Rockingham • Harvey • Kemerton • Bunbury (Clifton Road) including Busselton
2.2 ATCO Gas Australia GDS Assets There are six main asset classes of the ATCO Gas Australia GDS, each of which have been assessed separately for risk. The asset classes include: • Pipelines (Section 2.3.1) • Mains (Section 2.3.2) • Services (Section 2.3.3) • Pressure regulation facilities (Section 2.3.4) • Metering facilities (Section 2.3.5) • Kalgoorlie Odorant Facility (Section 2.3.6)
2.2.1 Pipelines ATCO Gas Australia distinguishes Pipelines as any pipe with a MAOP greater than 350kPa feeding more than one customer. Each of these pipelines is given an individual pipeline number allocated sequentially as new pipelines are constructed. Inclusive with this asset class are fittings used in the construction and repair. Pipelines begin/end from the following: • Outlet/Inlet valve of a regulator set • Branch fitting • End Cap/Flange A summary of ATCO Gas Australia pipelines is shown in Table 2-2.
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Table 2-2: ATCO Gas Australia GDS Pipeline construction breakdown
Pipeline Type MAOP (kPa) Length (km)1 Material Length (km)1
Transmission
Class 300 / 600 HP 3,600 – 10,200 123 Steel 123
HP Pipelines
Class 150 1,900 568 Steel 568 Class 125 1,050
Class 125 700 Steel 34 HP PE 600 141 PE100 107 500 SDR11
Note1 Table 2-2 comprises June 2017 data taken from the Asset Management Plan 2017- 2021(AST PL00003) which will continue to change throughout the life of the GDS Safety Case. 2.2.1.1 Steel Pipelines with MAOP’s between 1,900 and 10,200 kPa The GDS has approximately 151 km of Class 300 and 600 coated steel pipelines with MAOPs of 3,600 to 10,200kPa that range in diameter from DN50 to DN350mm.
2.2.1.2 Steel Pipelines with MAOP’s between 1,050 and 1,900 kPa The GDS has approximately 528 km of Class 125 and 150 coated steel pipelines with MAOPs of 1,050 to 1,900kPa that range in diameter from DN50 to DN350mm. 2.2.1.3 Steel Pipelines with MAOP’s of 700 kPa A section of the South Metropolitan sub-network of the GDS comprises approximately 46 km of Class 125 coated steel pipelines with a MAOP of 700 kPa which feeds the Fremantle Business District and an area extending from North Fremantle to Spearwood in the south, and east to Booragoon. The Class 125 700kPa MAOP steel pipelines range in diameter from DN80 to DN450 mm. 2.2.1.4 Polyethylene Pipelines with MAOP of 500 – 700 kPa PE Pipelines also operate in parts of the ATCO Gas Australia GDS with a design MAOP of 500, 650 or 700 kPa (HP PE). There are approximately 104 km of PE100 Pipelines feeding Regulator Sets supplying gas to PE Mains.
2.2.2 Distribution Mains Distribution Mains are defined as pipe which distributes gas a pressures less than or equal to 350kPa. Included in this asset class are the fittings used in the construction and repair of the pipe such as valves, tapping bands and couplings.
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Table 2-3: ATCO Gas Australia GDS Mains construction breakdown MAOP Length Kilometres Distribution Main Type Material (kPa) (km)3 (km) Steel 38 Distribution Mains in the 350 58 PE 20 Perth CBD Copper - 350 1,644 PE 1644 UPVC 5892 PE 1568 Steel 50 100 7,510 GI 0.19 Distribution Mains within the Coastal and CI 0.17 Kalgoorlie-Esperance supply areas (excluding Copper4 - the Perth CBD as UPVC 3568 described above) Steel 94 PE 70 7 3,747 GI 5.7 CI 10 Copper3 - Distribution Mains in the UPVC 139 Albany LPG Network 20 163 PE 24 (Great Southern supply 3 area) Copper -
Total 13,123 13,123
Note3 Table 2-3 comprises of June 2017 data taken from the Asset Management Plan 2017- 2021(AST PL00003) which will continue to change throughout the life of the GDS Safety Case Note4 Copper mains only exist within buildings which feed more than 1 customer and are not accounted for length.
2.2.2.1 Mains in the Perth CBD with MAOP’s of 350 kPa The ATCO Gas Australia CHP network is a section of the North Metropolitan sub-network of the GDS which feeds the Perth Central Business District (CBD), West Perth, East Perth, Northbridge and Highgate areas. It has a MAOP of 350kPa and currently operates via several regulator sets at pressures between 160 - 200kPa. The City Block section consists of predominantly coated steel construction in diameters ranging from 80 - 150mm, and some 63mm and 110mm diameter PE. Services connected to these mains are a mix of steel, stainless steel and PE. The North Perth and Northbridge sections consist of PE and steel mains of diameter varying from 40 - 110mm. Services connected to these mains are predominantly PE.
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2.2.2.2 Mains with MAOP of 350 kPa There are various PE sections of the GDS that operate between 70 - 350kPa, fed from either regulator sets or PRSs to end use consumers. These include the Ellenbrook and Busselton sub- networks and several other smaller areas. These mains and services range in diameters from 18 - 225mm. These pipes are either PE80 or PE100 with SDR 11, 13.6, 17, or 17.6.
2.2.2.3 Mains with MAOP of 100 kPa Sections of the ATCO Gas Australia GDS are fed from one or more Regulator Sets at an operating pressure of between 15 – 100 kPa. There are approximately 7,430 km of these Mains ranging in diameter from 40 – 635 mm. These Mains are predominantly of uPVC construction (~81%) with some steel (~1%), and PE (~18%). Fittings included in MP mains are Tapping bands, couplings and Service Tees. 2.2.2.4 Mains with MAOP of 7 kPa Sections of the GDS are fed from one or more regulator sets operating at pressures between 2 - 7kPa. These mains and services are constructed almost entirely from uPVC (~97%), with diameters ranging from 18 – 330mm. There are also some PE sections. 2.2.2.5 Mains in the Albany LPG Network with MAOP of 20 kPa The ATCO Gas Australia Albany network is a section of the Albany Distribution Network and operates at a pressure of 8 - 20kPa. The Albany network consists of predominantly uPVC mains and services, and some PE.
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2.2.3 Services Service pipe is used to supply gas to customers. A service starts from a pipeline or main and is branched off with a service tee and remains below ground until reaching the service riser. The service then continues above ground until it terminates at the inlet Valve of the customers meter. Services can operate at pressures available on the ATCO Gas Australia network and can be found in the materials identified in Table 2-2. A standard service runs in a straight line perpendicular to the main directly to the meter position unless obstructions are in the way.
Table 2-4: ATCO Gas Australia GDS Service construction breakdown MAOP Service Type Material (kPa) UPVC Steel CI 7 GI PE Copper UPVC Service Pipe Steel 100 PE Copper Steel 700 PE 1900 Steel >1900 Steel
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2.2.4 Pressure Regulation Facilities There are 6 distinct pressure regulating facilities operated by ATCO Gas Australia: • Pressure Reduction Station (PRS) • High Pressure Regulating (HPR) Set • Medium Pressure Regulating (MPR) Set • Boundary Regulators • Industrial/Commercial Pressure Regulation (Included in Metering Facility Section 2.2.5.2) • Domestic Pressure Regulation (Included in Metering Facility Section 2.2.5.3)
Table 2-5: Pressure Regulation Facilities
Inlet Pressure Range Outlet Pressure Range 5 Facility Type Number (kPa) (kPa) PRSs 1900-10200 700-1900 18 HPRs 700-1900 15-700 225 MPRs >7-350 7 299 Boundary Regulators >7-350kPa 1.25-7 143 Industrial/Commercial 7-1900kPa 1.25 - 800 10846 Domestic 7-350kPa 1.25 – 2.75 736890 Note5 Number of regulating facilities as of 21/6/2017. 2.2.4.1 PRS PRS are critical assets that allow the safe pressure regulation of gas from a higher variable inlet, to a lower set outlet pressure, controlled within a specified pressure interval for the full design flow range. They are supplied from the various laterals and transmission pipelines owned by ATCO Gas Australia with an outlet pressure greater than 1,000kPa supplying gas to the high pressure networks. A PRS will typically consist of a filter, inlet and outlet isolation valve, and a single active regulating stream with active monitor regulators and associated pressure sensing equipment. PRS have a standby stream identical to the active stream. PRS are also often fitted with pressure relief devices and over pressure protection, which is either incorporated in the regulator design or performed by separate safety elements. The GDS has 18 PRS supplying gas into the high pressure distribution networks. Some of these PRS are monitored for flow and pressure data via telemetry. The average age of the PRS is 19 years. These PRS are distributed across the network and located above ground in secured compounds with cyclone mesh fencing and locked access gates. To avoid unauthorised valve closures, which can lead to loss of gas supply to large number of consumers, important valves are locked in the required position.
2.2.4.2 HPR HPR sets allow safe pressure regulation of gas from a higher variable inlet to a lower set outlet pressure generally with an inlet pressure greater than 500kPa and an outlet pressure greater
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than 15kPa, with a few sets with an outlet pressure greater than 5kPa. They are supplied from the networks with MAOPs greater than 350kPa to supply gas into the distribution networks of lower MAOP. Some HPR, especially those supplying gas to discrete networks are critical assets. A HPR typically consists of a filter, inlet and outlet isolation valve, and an active regulating stream with a regulator and associated pressure sensing equipment. Some regulator sets are also fitted with pressure relief devices and over pressure protection, which is either incorporated in the regulator design or performed by separate safety elements. HPR sets have twin streams, with the majority on a twin stream active monitor configuration for reliability and to facilitate maintenance. 2.2.4.3 MPR MP sets are used for pressure regulation from 350kPa and 100kPa networks to supply gas into the 7kPa distribution networks. MP regulator sets have an outlet pressure less than 7kPa and an inlet pressure less than 350kPa. MP regulator sets are not critical assets. A MP regulator set typically consists of inlet and outlet isolation valve, and a single working regulating stream with active monitor regulator and associated pressure sensing equipment. MP regulator sets are predominantly smaller units that are installed in underground pits. The majority of these sets are of single stream active monitor configuration in integrated networks and can be shut down during maintenance. The newer sets have a filter with a single active regulator and slam shut valve.
2.2.4.4 Boundary Regulator Sets Boundary regulators are used to drop the pressure to a customer which has a long service such as multistorey dwellings. This is to prevent a high pressure break occurring on the customers’ property. Typically boundary regulators have a maximum inlet pressure of 350kPa and maximum outlet pressure of 7kPa.
2.2.5 Metering Facilities There are three main types of metering facilities: • Residential Meters • Commercial/Industrial Meters • Non-Billing Meter Metering facilities measure the flow rate at intervals throughout the network and prior to entering a customer’s premise. A metering facility is always located immediately downstream of a pressure regulator as described in Section 2.2.4. The types of meters used by ATCO Gas Australia are summarised in Table 2-6.
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Table 2-6: Metering Facilities
Pressure 6 Metering Facilities Range Meter Type Number
Turbine 34 Non-Billing Meter 7-1900kPa Vortex 42 Diaphragm 10515 Industrial/ Commercial Customer Metering 7-700kPa Rotary 284 Turbine 47 Domestic Customer Metering 7-350kPa Diaphragm 736890 Note6 Number of metering facilities as of 21/6/2017. 2.2.5.1 Non-Billing Meter Non-Billing meters are installed onto pressure regulating facilities. The purpose of the non-billing meter is to assist in network and security of supply modelling and billing across gas zones as part of UAFG calculations.
2.2.5.2 Commercial/Industrial Metering Commercial/Industrial metering is achieved through a meter set that typically consists of a working and a stand-by stream comprising of pipework, spool pieces, valves, filters, regulators and meter. The meters are generally of diaphragm, rotary and turbine type construction. Meter sets provide gas flows within prescribed pressure range and metering accuracy generally to commercial and industrial consumers. The inlet pressure to these meter sets range from 7kPa to 700kPa.
2.2.5.3 Domestic Metering The GDS contains approximately 737,000 domestic metering facilities with a standard domestic meter. These facilities supply gas from the 700kPa, 100kPa and 7kPa networks to consumers. The majority of domestic meters installed on the GDS are 2 litre cyclic capacity diaphragm meters. They have been proven through empirical results and demonstrated by their longevity, accuracy retention and in-service performance to have a life of 25 years.
2.2.6 Kalgoorlie Odorant Facility
ATCO Gas Australia own and operate an Odorant Facility at the Kalgoorlie Pressure Reduction Station) and Metering Facility (GS020), which doses natural gas supplied to the Kalgoorlie network with odorant concentrations in accordance with the requirements of Schedule 1 of the Gas Standards (Gas Supply and System Safety) Regulations 2000. The Kalgoorlie Odorant Facility consists of a NJEX YZ Direct Odorant System, odorant injection probe and a 490 litre (L) odorant tank which stores an approved odorant. The facility was commissioned in September 2014.
The odorant liquid stored at the facility is classified as a Class 3 (flammable) Dangerous Good and must be stored and handled in accordance with Australian Standard AS 1940-2004-The storage and handling of flammable and combustible liquids. Due to the quantity of liquid stored,
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the facility is only required to comply with Section 2 of AS1940 pertaining to minor storage requirements.
2.3 Composition of the ATCO Gas Australia GDS Asset Classes The asset classes’ described in Section 2.2 are constructed from several different materials. A material has been defined as an individual component which is used in the containment of gas. The materials associated with each asset class have been summarised in Section 2.3.1 to Section 2.3.3 and are approved through the Materials Management Process (ENS PR0029)[40]. Further detail on material sizes, manufacturers, suppliers and technical specifications can be found in the Technical Services Register (ENS PR0029 RG01)[41].
2.3.1 Pipeline, Mains and Service Components 2.3.1.1 High Carbon Steel pipe High Carbon Steel walled pipe is constructed of material conforming to American Petroleum Institute (API) Specification for Line Pipe, ANSI/API Specification 5L/ISO 3183:2007 (Modified), Petroleum and natural gas industries-Steel pipe for pipeline transportation systems[42]. The first steel pipeline constructed from these materials was the ATCO Gas Australia GDS Class 600, 9.5 km long, 350 mm OD HP 28 Harrow Street Lateral, from Harrow Street, West Swan to Ballajura, built in 1979. 2.3.1.2 Steel pipe Steel walled pipe is constructed of material conforming to API Specification 5L. In the 1940’s and 1950’s steel pipes with a coal tar enamel coating, which were not protected further with a Cathodic Protection (CP) system, were installed. Those that remain in service have been de- rated to operate at lower pressure. 2.3.1.3 PE100 pipe PE piping is Series 2 Metric Outside Diameter (OD) gas pipe, constructed of material conforming to AS 4130 Polyethylene pipe for pressure applications (AS 4130)[43], as follows: • PE100 SDR11; • PE100 SDR13.6; • PE100 SDR17; and • PE100 SDR17.6.
2.3.1.4 PE80 pipe PE piping is Series 2 Metric OD gas pipe, constructed of material conforming to AS 4130 as follows: • PE80 SDR11; • PE80 SDR13.6; • PE80 SDR17; and • PE80 SDR17.6.
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2.3.1.5 Unplasticised Poly-vinyl Chloride pipe Unplasticised Poly-vinyl chloride (uPVC) piping Is Type 2 Class 100 constructed of material conforming to the now superseded AS1464.1 - 2 Plastics pipes and fittings for gas reticulation – plasticized PVC (UPVC), Parts 1, 2 (AS 1464)[44]). uPVC pipes, used now only for repairs to existing uPVC assets, were first installed in 1965 for Mains and Services with MAOP’s up to 100 kPa. 2.3.1.6 Galvanised (Ductile) Iron pipe No longer installed on the ATCO Gas Australia GDS, galvanised iron pipe was manufactured to American Society of Mechanical Engineers Welded and Seamless Wrought Steel Pipe, ASME B36.10M-2004[45] and coated with zinc to protect from rust. These pipes were commonly manufactured with screwed ends and new installations constructed from this material began in the early 1900’s. Use of this material was discontinued after the introduction of UPVC in 1965.
2.3.1.7 Cast Iron pipe No longer installed on the ATCO Gas Australia GDS, cast iron was used for gas reticulation in early years for its comparatively high corrosion resistance qualities. Pipe was commonly manufactured with a bell-and-spigot ends with lead and hemp socket joint. Cast iron has less tensile strength and shock resistance than steel and was manufactured to American Society for Testing and Materials Standard Specification for Grey Iron Castings, A 48/A 48M – 03[45]. Cast Iron pipes were used from the first construction of the ATCO Gas Australia GDS in the late 1800’s and were installed up until the mid 1960s. 2.3.1.8 Copper Pipe Copper pipe is installed by ATCO Gas Australia for above ground connections to customer meters. This copper pipe is typically in the form of a copper riser connecting the end of a below ground PE services to a consumers gas meter. This pipe is also used in above ground installations where multiple meters may be located in a single property boundary such as multi storey and multi occupancy dwellings. This pipe is typically places on the external walls of buildings however may be used internally provided sufficient ventilation and compliance to building requirements. 2.3.1.9 Service Tees Service tees are used to tap into a gas main and connect a service pipe. These tees may be welded directly onto the main our form part of a tapping band which mechanically attaches to the main through a compression seal.
2.3.1.10 Tapping Bands Tapping bands are located on the gas network and potential leak sources. These are placed onto the gas mains for the purpose of adding a service or flow stopping. 2.3.1.11 Couplers Couplers are used to connect pipe together through the construction phase of a pipeline as well as during maintenance. 2.3.1.12 Valves Valves are placed on pipelines, mains and services to assist in the isolation of the pipe for commissioning, decommissioning, maintenance and emergency isolation.
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2.3.2 Pressure Regulation Components Pressure regulating facilities consist of the same components of metering facilities described in Section 2.3.3 with the exclusion of the Gas Meter. These components may be housed in four distinct types specified in which are described in ATCO Gas Australia Asset Class Plan – Pressure Regulation Facilities (AST PL00012)[47] and have been summarised as per Table 2-7.
Table 2-7 Types of Pressure Regulating Facilities Facility Type Type PRSs Above ground regulating facilities Above ground regulating facilities Regulator set contained in an above ground cabinet (Kiosk) HPRs Cocon brand self contained regulator set Regulator set in pre-cast concrete pit with Gatic brand lids Regulator set in pre-cast concrete pit with a pneumatically lift-up lid Above ground regulating facilities MPRs Regulator set contained in an above ground cabinet (Kiosk) Regulator set in pre-cast concrete pit with Gatic brand lids Boundary Regulator in pre-cast concrete pit Regulators Regulator in pre-cast plastic pit
2.3.3 Metering Facility Components The primary components of concern with metering facilities are the types of meters described in Table 2-8. In addition to the meter, a metering facility also includes: • Valves • Filters • Pressure Reliefs • Flanges • Pipe
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Table 2-8 Types of Gas Meters Meter Model Residential E, F, HJJ, M, M6EF, MF, MZ, P, WE, E602, EE602, M5T, ME602 M6EW, M6WA, M8A, ME610, M10AL Commercial/Industrial/Non-Billing Diaphragm M12AL, M12SL M18AL, M25AL, M30AL, M40AL, M65AL, M150AL Rotary M25DR, M40DR, M85DR, M150DR, M200DR, M300DR, M450DR M100RMG M100ELR, M160ELR, M250ELR, M400ELR, M650ELR M160IR, M250IR, M650IR, M1000IR M85RR, M140RR, M200RR, M300RR, M450RR, M654RR Turbine M300GT, M400ACT, M400ELT, M500GT, M1700DT, M1700GT, M1700RT, M850GT, M2500GT Vortex M23V
2.3.4 Odorant Facility Components The odorant facility at Kalgoorlie is a unique asset owned and operated by ATCO Gas Australia, the components of this asset are described in the as build drawing for the facility . Key components include: • Injection Pumps • Odorant Tank • Scrubber Tank • Verometer • Relief Valves • Pressure Gauges
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2.4 Safety Features and Systems of Listed Parts of Facilities The risk assessments which together constitute the ATCO Gas Australia GDS Formal Safety Assessment (FSA) as described in Section 4, identify various design features, operational systems, procedures and safeguards either already in place, or required to be put into place, to increase the levels of integrity and inherent safety of the ATCO Gas Australia GDS. This section further describes a number of these Safety Features and Systems, considered to be key risk control measures for the ATCO Gas Australia GDS.
2.4.1 GDS Isolation In the event of a GDS incident, or emergency, the GDS is equipped with isolation valves (manual operation) installed to facilitate GDS isolation. Asset Class Plan - Pipelines, Mains and Services (AST PL00009)[48] provides a description of isolation valves (pipelines and mains) and service valves. Refer to sub-sections 2.4.1.1 and 2.4.1.2 for the January 2016 details of GDS isolation and service valves. The location of GDS isolation valves is obtained from ATCO Gas Australia’s; • Geographic Network Information System (GNIS), refer to Section 3.10; and • Various network and pipeline isolation plans, procedures and schematics, refer to section 3.15.2 Refer to section 3.15.2 for details of ATCO Gas Australia’s systems for GDS isolation. 2.4.1.1 Isolation Valves There are approximately 2,484 main isolation valves in the GDS, of which 887 are on HP mains while 1,597 are on LP/MP mains. The GDS consists of various sizes of HP main isolation valves ranging from 50mm to 250mm. In the event of pipeline emergency, sections of the network may require isolation in order to rectify the problem while minimising the potential impact to safety, network integrity and continuity of gas supply to the lower pressure networks. LP/MP main isolation valves in the network ranges from 40mm to 225mm in sizes. Out of 887 HP main isolation valves, 261 are for line use while 626 are either for branch or blowdown uses. HP main isolation valves in the GDS are predominantly of steel material (88%). There are approximately 1,647 LP/MP main isolation valves in the GDS. Pipeline mainline isolations valves are maintained in accordance with Asset Class Plan - Pipelines, Mains and Services (AST PL00009). 2.4.1.2 Service Valves Service valves are installed on mains’ off-takes to stop the flow of gas to the connected consumer’s service for maintenance or safety purposes. The service valve and associated fittings shall be fit for purpose in providing sectional isolation as described in AS4645.1, section 4.9.2 (Network management). There are approximately 18,564 services valves in ATCO Gas Australia’s GDS, of which 5,033 are plastic service valves. Plastic service valves have been extensively used in the gas distribution network since the introduction of uPVC pipes in 1965.
2.4.2 Pressure Regulation and Overpressure Protection Monitoring and Control of gas pressure in a pipe is recognised by AS 4645 as an important safety and consequence mitigation technique for gas distribution systems.
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The monitoring of ATCO Gas Australia GDS system performance includes monitoring gas pressure in order to detect and record pressure excursions that exceed limits detailed in Assets & Systems Performance & Health Monitoring 2013 (AST PR0005)[49]. ATCO Gas Australia monitors pressure at selected: • Residential locations; • Commercial/ Industrial Meter Sets (designed in accordance with the requirements of Engineering Services Design Guideline Meter Design and Selection (ENS PR0002)[50]; • Regulator Sets (designed in accordance with the requirements of Engineering Services Design Guideline Regulator Sets (ENS PR0015)[51] including OPSO); • PRS sites (designed in accordance with the requirements of Engineering Services Design Guideline Regulator Sets (ENS PR0015)). 2.4.2.1 Pressure Monitoring and Network Performance Pressure monitoring location data is entered into a computer model (Designed in accordance with requirements of Flow Computing and Telemetry Equipment (NCO PR0001)[52] of the ATCO Gas Australia GDS, thus identifying points at which high and low pressure excursions have actually occurred within the ATCO Gas Australia GDS. System monitoring data recorded at these sites is compared to the model outputs and thus used to review the accuracy and thereby improve the network model that is used when planning for new gas distribution assets. 2.4.2.2 Gas Pressure Control and Safety Devices Gas pressure control regulators and other safety devices are installed to protect ATCO Gas Australia GDS components downstream of PRS and regulators from over pressure and are employed in various configurations. Components at pressure control equipment sites include upstream and downstream isolation valves, an active regulator, and one or more of the following safety device(s): • Over-pressure shut-off (OPSO) valve/device, including slam-shuts; • Monitor regulator; • Pressure relief valve; or • Pressure control equipment with inlet pressure greater than 200 kPa.
2.4.2.3 PRS and Regulator Sets configuration PRS’s and Regulator Sets often utilise pressure regulator and safety device configurations in parallel duty and stand-by streams which allows for 100% redundancy, for inlet pressures greater than 350kPa only. HPRs with inlet pressures between 8kPa and 350 kPa utilise duty and bypass. These are designed to allow the stand-by devices to assume control of supply pressure and flow automatically upon failure of the active devices. A number of PRS’s and Regulator Sets on Pipelines are monitored for inlet and outlet pressures and are currently maintained in accordance with Network Maintenance Strategy (AST ST00002)[53] on four (4) month cycles. Selected Regulator Sets fitted with an Overpressure Shut-Off (OPSO) device are capable of alarming on activation and low inlet pressure.
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2.4.3 Corrosion Protection Design Corrosion of steel pipes has been identified as a hazard in the FSA in Section 4, and is recognised by both AS 4645 and AS 2885 as a threat to continued safe operation of a pipeline or gas distribution system. Corrosion protection systems for the ATCO Gas Australia GDS are designed and constructed according to Corrosion Mitigation Systems (NCN PR0002)[54]. Sections of buried steel pipe are provided with a coating system for primary corrosion protection; supplemented by either an Impressed Current Cathodic Protection (ICCP) system or the use of sacrificial galvanic anodes as secondary protection. Below ground coating systems are supplied and installed in accordance with the manufacturers’ specifications, and specialised metals (e.g. stainless steel and brass), galvanising or coatings approved by ATCO Gas Australia, in Corrosion Mitigation Systems (NCN PR0002), are employed on above ground pipework and associated facilities for protection from corrosion. Coatings are applied to above ground pipework, and condition assessed, in accordance with Coating Refurbishment and Repairs (ENS PR0022)[55]. Internal corrosion protection of metallic assets is heavily reliant on the gas specifications as described in Section 3.18.1 for internal corrosion. 2.4.3.1 Cathodic Protection CP systems are inspected in accordance with AS 2885.3 at frequencies outlined in Table 16 ‘CP Pipeline Frequency Survey List as at 1/08/2013’ in the Asset Class Plan – Cathodic Protection Systems (AST PL00006)[56] Criteria used for assessing effectiveness of the CP systems are based on AS 2832.1. Prior to the 1960’s, steel pipes with MAOP’s below 500 kPa were installed without supplementary Cathodic Protection (CP). These pipes were coated with coal tar enamel or epoxy coatings, or alternatively constructed of materials such as galvanised or cast iron that, at the time of installation, were considered to provide sufficient protection against corrosion, without any further requirement for supplementary CP. Steel pipes with MAOP’s below 500 kPa were being progressively subjected to condition assessment, and their MAOP’s lowered or in some cases replaced, however, condition assessments are no longer being conducted as the metallic Mains replacement project covers aging steel (refer to Section 3.16.3 for further details on this replacement). Galvanic Anode Cathodic Protection The CP system performances for steel pipes are surveyed on the basis of the previous CP system performance result. Table 4 ‘CP Rating’ in the Asset Class Plan – Cathodic Protection Systems (AST PL00006) outlines the CP system performance on high pressure pipelines. If the CP system performance is rated as ‘good’ or ‘fair’ the pipe is surveyed annually. If the CP system performance is rated as ‘poor’ or ‘under protected’ the pipe is surveyed every 6 months. The CP system performance for steel pipes with MAOP’s of 100 kPa and crossings are surveyed annually. Further details regarding these frequencies are available in the Asset Class Plan – Cathodic Protection Systems (AST PL00006), which details survey frequencies for steel pipes and crossings.
Impressed Current Cathodic Protection
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ICCP systems on the ATCO Gas Australia GDS are surveyed for effectiveness in accordance with the ATCO Gas Australia Asset Class Plan – Cathodic Protection Systems either every 2 months, for systems that are not fitted with remote alarms, or every 6 months, for systems that are fitted with remote alarms. 2.4.3.2 Protective Coatings The surfaces of new pipework, fittings and equipment operating with MAOP’s of 500 kPa or greater are treated in accordance with AS 2885, and Parts 1 and 2 of AS/NZS 2312:2014 Guide to the protection of structural steel against atmospheric corrosion by the use of protective coatings[57]. Specific information on each coating is available within ATCO Gas Australia Engineering Services Design Guidelines for Pipelines, Meter Sets, Regulator Sets, Valves and Corrosion Mitigation Systems. ATCO Gas Australia utilises a factory applied protective coating on underground steel pipes which consist of a trilaminate 3 layer polyethylene coating, consisting of Fusion Bonded Epoxy, adhesive and PE100. Historically, steel pipes with MAOP’s below 500 kPa were coated with coal tar enamel or epoxy resin. Welded joints on steel pipe, valves and fittings intended for below ground applications, that have not been factory coated as detailed above, are coated in accordance with the engineering specification Coating and Refurbishment and Repairs (ENS PR0022), or as detailed in the specific Project Management Plan (PMP) for the pipe to be installed – refer document Project Management Plan (ENS PL0002)[58].
2.4.4 Electrical Isolation Steel Pipelines may be susceptible to a range of electrical hazards, such as induced voltage, lightning and fault currents along sections of the Pipeline. These electrical hazards can result in significant voltages that can be hazardous to the Pipeline itself, or to personnel who may come in contact with the Pipeline. High voltages can arise due to a variety of causes, such as earth potential rises in the vicinity of electrical earthing under fault conditions, voltages induced on the Pipelines when faults occur on nearby powerlines, particularly when the Pipelines are in the vicinity of HV powerlines, or a lightning strike on the Pipeline. One of the mechanisms for protecting steel Pipelines from corrosion is the application of anti-corrosion coatings as defined in ATCO Gas Australia engineering specification Coating and Refurbishment and Repairs (ENS PR0022). These anti-corrosion coatings mean that the Pipelines are electrically insulated and can transmit hazardous voltage along the Pipeline to above ground ATCO Gas Australia assets. Therefore above ground sections of the ATCO Gas Australia GDS must be isolated from the risk of these hazardous voltages. To protect ATCO Gas Australia assets, staff and the public against electrical shock due to transmission of electric current, steel Pipelines subject to the requirements of AS 2885 are designed to be electrically isolated from earthed and above-ground structures through controls such as separation distance, pipe coatings with electrical insulating properties, insulating joints, gaskets and surge diverters. Electrical isolation is designed to satisfy the safety requirements of AS/NZS 4853:2010 Electrical hazards on metallic pipelines (AS/NZS 4853.2010)[59] and is specified in Engineering Services Design Guideline Meter Design and Selection (ENS PR 0002). In addition earthed aboveground pipework must be electrically isolated from cathodically protected pipes to maintain integrity of the CP system.
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Hand tools such as prodders (Refer to engineering specification Ground Penetrating Equipment (ENS TS040)[60] and impact searcher bars; have insulated handles to protect personnel against electric shock. (Refer to Safe Work Instruction (SWI) Locating Underground Gas Leaks (SWI GE 002)[61]. Continuity bonding is utilised in accordance with Continuity Bond (SWI TE 002)[62] to mitigate against; • the risk electric shock or electrocution due to voltage differentials across non connected metallic pipes and, or other metallic structures caused by stray currents/electrical faults, and • the risk of static generated spark across non connected gaps in pipe work and ignition of Natural Gas or LP Gas.
2.4.4.1 Insulating Joints, Gaskets and Surge Diverters To help prevent the escape of energy from an electrical fault, which could lead to harm to ATCO Gas Australia personnel or ATCO Gas Australia asset damage, from being conducted along long steel pipe sections, earthing points and insulating joints are installed as required to assist in rendering them non-electrically continuous. Insulating joints are typically fitted with a polarisation cell, low voltage surge diverter, or spark gap arrestor device to cope with electrical fault surges from third-party sources and lightning. Insulating joints may be in the form of welded monolithic joints or insulation gasket kits typically installed at valve flange access points where required. Above ground Regulator Set and Meter Set facility pipework is electrically isolated from below ground pipework by installing insulation gasket kits on riser flanges (Refer to Coating Refurbishment and Repairs (ENS PR0022)). 2.4.4.2 Induced Voltage and Pipeline Earthing Where it has been identified as a threat the risk of electrical shock associated with induced voltage resulting from HV power lines in the vicinity of ATCO Gas Australia steel Pipelines subject to the requirements of AS 2885, lightning or other sources is mitigated through the use of additional earthing on Pipelines. These steel Pipelines are earthed at PRS and mainline valve sites, where required, via polarisation cells to mitigate the effects of possible electrical fault surges from external sources. The above ground piping, pipe supports, fencing and other above ground metallic structures at PRS sites are earthed in accordance with AS/NZS 4853. The earthing system is designed to allow currents to follow the most direct route through the earthing system and to discourage flow via connections to electrical equipment. For this reason, connections between electrical equipment earth bars and the earth grid are made at a single point. Surge arrestors and galvanic isolation devices fitted to the ATCO Gas Australia GDS are implemented in accordance with AS 2832. New installations of insulating flanges will be protected with a surge diverter, and ATCO Gas Australia began a programme to retrofit existing insulating flanges with surge diverting equipment in 2010. To mitigate damage to coatings of steel Pipelines subject to the requirements of AS 2885, and for personnel safety, induced voltage earthing is installed where the assessment of risk has determined that there is a risk of induced voltages from HV powerline. Earthing points connect to Pipelines through test point junction boxes or below ground connection pits and consists of one or more of the following:
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• zinc conductor(s) buried in the pipe trench; • a galvanised iron conductor with sacrificial anodes buried in the pipe trench; • surface groundbeds, consisting of a number of zinc or magnesium anodes, buried in a trench parallel to the Pipeline; and • deepwell groundbeds, consisting of a number of zinc anodes installed in a borehole next to the Pipeline at up to 100 m depth in order to reach minimum required soil resistivity. The electrical induction effects of high voltage powerlines parallel to an underground gas steel pipeline, which may compromise the effectives of cathodic protection, are known to ATCO Gas Australia. Western Power maintains close communication with Asset Services where such powerlines are planned to run, parallel to an ATCO Gas Australia underground gas steel pipeline, which has been identified through DBYD. Western Power provides calculations that determine the earth potential rise and / or low frequency induction to ATCO Gas Australia to determine what effects if any such parallel power lines may have on the ATCO Gas Australia asset. Such information assists ATCO Gas Australia to monitor assets with effective maintenance programs to manage any threats to the pipeline.
2.4.4.3 Lightning Protection The purpose of the lightning protection earthing system is to limit the earthing system's resistance to 'remote earth'. This limits the voltage rise of the earthing system (and the equipment connected to it) when there is a lightning strike. The earthing system is designed to allow lightning currents to follow the most direct route through the earthing system and to discourage flow via connections to electrical equipment. For this reason, connections between electrical equipment earth bars and the earth grid are made at one point only. Metallic parts of structures not subject to CP potential are equipotential bonded (i.e. bonded to the same earth system) in accordance with AS/NZS 2381.1-2005 Electrical equipment for explosive gas atmospheres - Selection, installation and maintenance Part 1 General requirements[63]. This is designed to prevent large potential differences in electrical equipment and cabling during lightning strikes. 2.4.4.4 'Step’ and ‘Touch' Potentials ‘Step’ and ‘touch’ potentials, or voltage differences between an individual and a grounded object due to an individual’s distance from the grounded object when it has been energised, may arise from causes including lightning strikes or electrical faults causing grounded objects (such as steel pipes or equipment) to become energised. On ATCO Gas Australia GDS steel components that are accessible above ground, such as PRSs, Regulator Sets and Meter Sets connected to pipes with MAOP’s of 500 kPa or greater the following control measures are progressively being installed: • earthing in accordance with AS/NZS 4853 to discharge current to ground and reduce likelihood of exposure to harmful ‘step’ and ‘touch’ potentials; • low resistance earth grids at PRSs, intended to limit induced voltage, and thus ‘step’ and ‘touch’ potentials; • grading conductors intended to control the rate of change of soil surface potential and thus reduce the likelihood of exposure to harmful ‘step’ and ‘touch’ potentials; and
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• high resistivity surface finishing, such as blue metal, around Pipeline equipment for increasing allowable ‘step’ and ‘touch’ potentials with the intention of reducing body current for a given level of ‘step’ and ‘touch’ potential. Additionally, Coating and Refurbishment and Repairs (ENS PR0022), Volt Stick (SWI TE 001)[64], Continuity Bond (SWI TE 002) and Earth Mat (SWI TE 015)[65] have been developed to mitigate the ‘step’ and ‘touch’ potential.
2.4.5 Hazardous Area Classifications Fixed electrical equipment installed within the Hazardous Areas, are to be installed in accordance with AS/NZS 60079.10.1:2009 Explosive atmospheres Part 10.1: Classification of areas-Explosive gas atmospheres (IEC 60079-10-1, Ed.1.0(2008) MOD) (AS/NZS 60079.10.1[66] and AS 2381 Electrical equipment for explosive gas atmosphere – Selection, installation and maintenance (AS 2381). If portable electrical equipment is required to be brought into those Hazardous Areas the risks are to be managed in accordance with Permit to Work System (TCO PR0007), refer to Section 3.6.2 and AS 2381.
2.4.6 System Monitoring 2.4.6.1 (Telemetry) ATCO Gas Australia considers electronic monitoring equipment, installed in accordance with Flow Computing and Telemetry (NCO PR0001)[52] to enable gas pressures, temperatures and flowrates on the ATCO Gas Australia GDS to be recorded and/or monitored, to be an important mechanism in assessing ongoing performance of the ATCO Gas Australia GDS. Changes in gas pressure, temperature or flowrates can indicate potential faults or excursions on the ATCO Gas Australia GDS, which may otherwise go undetected. Electronic monitoring equipment is installed and maintained on the ATCO Gas Australia GDS and records gas pressures, temperatures and flowrates or a selection of these. ATCO Gas Australia retrieves and validates this monitoring data. The information that is transmitted to the ATCO Gas Australia GDS Control Room from monitoring equipment includes pressure, temperature and flow monitoring data, and OPSO device activation or fault information. ATCO Gas Australia procedural responses to alarms are described in Control Room Response to Network Monitoring Devices (CTR PR0004)[67]. Data collected by electronic monitoring is used to plan immediate response repairs to the ATCO Gas Australia GDS and for long term planning (refer to Asset Class Plan – Telemetry Equipment (AST PL00013)[68]).
2.4.6.2 Network Data Visualisation ATCO Gas Australia utilizes in-house software package which displays network data visually on an interactive map. The software assists dynamic network capacity modelling using real time data to support network operational decisions in terms of planned and unplanned interruptions. It will also enable improved utilisation of the network thereby reducing or deferring network reinforcement requirements. PMD monitoring sites have been installed within the various sub networks along with the addition of flow monitoring to a number of existing facilities.
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2.4.7 Danger Marker Tape and Tracer Wire A risk was identified to the integrity of underground pipes due to impact from third party external interference threats. To minimise this risk a number of controls described within this Safety Case have been implemented two of which are danger marker tape and tracer wire. Since 2005, danger marker tape has been installed 300 mm above buried plastic Mains and Services (prelaid Service to customer’s boundary) that have been laid within common utilities trenches (new subdivisions) in the road reserve and whose alignment is in accordance with the Utility Providers Code of Practice for Western Australia (Dial Before You Dig WA Ltd)[69]. In addition, since 2007, tracer wire has been attached to new plastic prelaid Services. Tracer wire and danger marker tape is to comply with the specifications in Gas Main Marker Tape (ENS TS027).[70]
2.4.7.1 Danger Marker Tape Since March 2005, ATCO Gas Australia steel pipelines designed in accordance with Engineering Services Design Guideline Pipelines (ENS PR0019)[71], AS 2885, or Mains designed in accordance with AS 4645 (or previous standards that applied: AS 1697 Installation and maintenance of steel pipe systems for gas, (AS 1697)[72]; and AS 4645–2005 Gas distribution network management (AS 4645-2005)[73], and installed with open cut techniques, have buried danger marker tape installed, typically 300 mm above them, following construction. When third parties are hand-excavating, mechanically excavating or conducting other form of ground disturbing works they may expose, dig or lift up the danger marker tape prior to making contact with the pipeline, Main or Service. The visible presence of the danger marker tape is to alert the third party that a gas pipeline, Main or Service is located below and that they should cease the operation with immediate effect. Additionally, steel pipes can be located by personnel using equipment to induce a voltage into the pipe, which can then be located using electrical location equipment.
2.4.7.2 Danger Marker Tape with Integral Tracer Wire Since April 2007, ATCO Gas Australia PE Pipelines designed in accordance with Engineering Services Design Guideline Pipelines (ENS PR0019), AS 2885, or Mains designed in accordance with AS 4645 (or previous standards that applied: AS 1697; and AS 4645-2005), and installed with open cut techniques, have buried danger marker tape with integral tracer wire installed, in accordance with Common Trench Gas Infrastructure (SWI CO 028)[74], typically 300 mm above them, following construction. The tracer wire enables personnel using equipment to induce a voltage into the wire, which can then be located using electrical location equipment. 2.4.7.3 Tracer Wire Danger marker tape cannot be installed with PE pipes installed using trenchless techniques. Since April 2007, ATCO Gas Australia PE pipes designed in accordance with Engineering Services Design Guideline Pipelines (ENS PR 0019), AS 4645 (or previous standards that applied prior to 2008: AS 3723 Installation and maintenance of plastics pipe systems for gas (AS 3723)[75] (from 1989 to 2004); AS 3723 and AS 4645–2005 (from 2005 to 2007)), and installed using trenchless techniques, do not have danger marker tape installed. Instead, these PE pipes have tracer wire alone attached to the pipe prior to installation, in accordance with Engineering Services Design Guideline Pipelines (ENS PR 0019) and Common Trench Gas Infrastructure (SWI CO 028).
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Tracer wire can be located by personnel using electrical location equipment.
2.4.8 Pipeline Marker Signs Above ground pipeline marker signs are installed in the vicinity of High Pressure pipelines and Mains, following construction. The purpose of the signs is to provide a means of warning third parties of the presence of Pipeline or Mains to further reduce the risk from third party external interference and threats. In accordance with the Engineering Services Design Guideline Pipelines (ENS PR 0019), pipeline marker signs, comply with Technical Specification Gas Warning Signs (ENS TS023)[76], and are installed on High Pressure Pipelines. Pipeline Marker Signs have also been installed in critical locations of the LPG network as defined by the Albany LPG Network Formal Safety Assessment (TCO RP 0199)[227]. The following are principal gas pipeline marker signs location criteria: • gas pipeline marker signs are to comply with requirements of AS 1319 Safety signs for the occupational environment[77]; be double sided; and positioned along the pipe route; • be installed at a distance in compliance with the requirements of Clause 4.4 of AS 2885.1; • be located both sides of road and railway crossing; • be located both sides of creek, drain or river crossings; and • be located such that line of sight is maintained between signs.
2.4.9 Physical Security and Impact Protection Measures Physical security measures for the ATCO Gas Australia GDS include the following provisions: • security fencing and lockable gates for selected aboveground facilities including PRSs; • key operated access to valves on above ground facilities, including selected Meter Sets, Regulators Sets, PRSs, Mainline Valve sites; • specialised equipment required for access into below ground pits, including Regulator Sets and valve pits; • meter boxes for domestic and some commercial gas meters as per Meter Boxes for AL8- 18 Gas Meters (ENS TS001)[78] which are located in safe locations as defined by Gas Meter Box Location Handbook (NCN RF08)[79]. • impact protection measures are implemented in accordance with Damage Prevention Management Guideline for ATCO Gas Facilities (ENS GL0006)[80], and include: • inherent protection provided by material of construction (e.g. steel pipe) • bollards and railings installed around above ground facilities (e.g. PRS, Meter Sets) to protect against impact, particularly from vehicles; • steel cabinets to house Regulator and Meter Sets; • easements and road reserves at selected locations provide protection via physical separation; • services installed within shafts or ducts at selected locations; • support brackets to provide physical strength to pipe installations; and
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• PE Mains bridge crossings, under major highyways and railways are in a sleeve to protect the asset from external forces and third party impact[82].
2.4.10 Buried Pipe Key Physical Protection Mechanisms 2.4.10.1 Depth of Cover The depth at which pipe is buried is in accordance with the ATCO Gas Australia Engineering Services Design Guideline Pipelines (ENS PR 0019) and Pipeline Installation Depth of Cover (ENS WI 023)[81]. Such depth is considered to decrease the likelihood of unintended physical interference with, or damage to, that pipe. The procedures given to personnel and contractors to adhere to these depths of covers are Common Trench Gas Infrastructure (SWI CO 028), Installing a Plastic Gas Main (SWI CO 020)[82] and Installing a Plastic Gas Service (SWI CO 002)[83]. The design of the ATCO Gas Australia GDS stipulates that sections of Pipelines are buried at a nominal distance of 1200 mm below the finished surface grade for pipeline MAOP greater than 1,050 kPa. The depth of cover is 900 mm for pipeline MAOP less than 1,050 kPa. AS 2885 Table 5.2.2 specifies a minimum required depth of cover of 750 mm for both R1 and R2 location class for normal excavations. The additional depth of cover is intended to provide an additional physical control for increased protection against penetration of the Pipeline. For mains and services, the depth of cover ranges between 1200mm and 300mm depending on scenario in accordance to AS 4645 requirements. 2.4.10.2 Buried Concrete Slabs and Concrete Encasement Third parties working adjacent to buried Pipelines constitute a potential threat of interference with the ATCO Gas Australia GDS. As a result of this, or in some cases a reduction in depth of cover due to events that have occurred subsequent to the date of initial installation or modification of the pipe, concrete slabs have been placed above, or reinforced concrete encasement placed around, ATCO Gas Australia GDS Pipelines in various locations. Concrete Protection for Gas Pipelines (ENS PR0005)[84] describes the process ATCO Gas Australia uses for determining when slabbing is to be considered for protecting a buried pipeline – the premise being that concrete slabbing protection is determined by the MAOP of the pipeline, not its material of construction. The locations of these protective measures are identifiable from records and databases maintained by ATCO Gas Australia including Pipeline ‘as-built’ drawings, physical inspection and overviews available through GNIS.
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3. SAFETY MANAGEMENT SYSTEM (SMS) The Safety Management System describes the framework of systems used for managing the ATCO Gas Australia GDS so that reasonable and practicable steps are taken for any Prescribed Activity to be carried out in a manner that provides for the safety of persons, and avoids or minimises damage to property, inconvenience, or other detriment, hereafter referred to as the SMS, as it exists at the time of approval of the Safety Case, and seeks to demonstrate that the SMS meets the requirements of the GSSS Regulations. The SMS provides personnel at all levels of the organisation with a ‘road map’ of systems in place to provide direction for Prescribed Activities involving the ATCO Gas Australia GDS so that they may be conducted safely and in accordance with the provisions of the relevant systems, and to manage risks associated with these activities to and acceptable level, or Intermediate and “As Low As Reasonably Practicable” (ALARP).
3.1 Leadership and Commitment
3.1.1 ATCO Gas Australia Corporate Reporting Structure The activities of ATCO Gas Australia are predominantly managed through the governance and reporting structure outlined in Table 3-1 below.
Table 3-1: Governance and reporting in the ATCO Gas Australia structure Entity Functions and Accountability Functions: • Reviews and monitors (and meets on a monthly basis (and if and when required)) execution of business strategy and delivery of business plan objectives, including workforce ATCO Gas Australia and network safety and risks. 1. Executive Management Accountability: Team • Board of ATCO Gas Australia Pty Ltd and Board of ATCO Gas Australia GP PTY LTD (Australian parent company); and • Dedicated Audit Director appointed by Board of ATCO Limited (ultimate parent company). Functions: • Reviews and monitors execution of business strategy and ATCO Gas Australia delivery of business plan objectives, including workforce 2. Board and network safety and risks. Accountability: • Australian parent company (as 100% owned subsidiary).
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Entity Functions and Accountability Functions: • Board of parent company of ATCO Gas Australia – meets minimum 3 times (scheduled) per year; • ATCO Gas Australia President on behalf of the Executive Management Team attends the Board meetings to account ATCO Gas Australia GP for the performance of the company and management; and. 3. Board • Discusses, endorses and approves strategies and monitors operational and financial performance including against business plans. Accountability: • Parent company Canadian Utilities Limited and ultimate parent company ATCO Limited (Canada). Functions: • Meets minimum 3 times (scheduled) per year and includes ATCO Australia POS review of workforce and management of network safety and Risk Management risk. 4. Committee (ATCO Gas Reports to: Australia GP Pty Ltd) • ATCO and CU Risk and Audit committees • ATCO Gas Australia GP Board. Functions: Operational Risk • Establishes and manages the implementation of policies, Management and procedures and risk management programs for the 5. Compliance Committee company – meets at least quarterly. (ORMCC) (ATCO Gas Accountability: Australia) • Key risks reported to ATCO Australia POS risk management committee. Functions: • Reviews HSSE performance and ATCO Limited internal Health, Safety, Security audit and finance teams – meets on a monthly basis; and & Environment (HSSE) • Reviews HSSE incidents, including: injuries to workers / 6. Committee (ATCO Gas contractors / public, first aid and lost time. Australia / ATCO Accountability: Australia) • Key actions reported to Dedicated Audit Director risk management committee and ATCO Gas Australia GP Board.
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Entity Functions and Accountability Functions: • Review operational and financial performance for each business unit including workforce and network safety and risk - meets on a monthly basis (and if and when required); ATCO Australia POS and. 7. Executive Management • Reviews and monitors performance of ATCO Gas Australia Committee (EMC) against business plan objectives and business strategies (as well as other operating subsidiaries). Accountability: • Key actions and statistical data reported to ATCO Australia GP Board.
3.1.2 Resources 3.1.2.1 General ATCO Gas Australia is headquartered at the Jandakot Depot, located at 81 Prinsep Road, Jandakot, Western Australia. Under the direction of its President as endorsed by the various committees, and ultimately the ATCO Gas Australia and ATCO Gas Australia GP Boards, strategies and policies are formulated and implemented for operation and maintenance of the ATCO Gas Australia GDS. These strategies and policies support the coordination of the future design and construction activities relating to the ATCO Gas Australia GDS. ATCO Gas Australia GDS depots and offices are located and staffed as follows:
Table 3-2: ATCO Gas Australia depot and office locations and staffing levels Office Title Staffing Level Address Head office & Jandakot Depot 285 81 Prinsep Road, Jandakot
Kalgoorlie Depot 3 14 Broadwood Street, Kalgoorlie
Albany Depot 5 3a/230 Chester Pass Rd, Walmsley
Bunbury Depot 6 7 Leichardt St, Davenport
Geraldton Depot 4 17a Stow Street, Geraldton
Wangara Depot 31 1/33 Triumph Avenue, Wangara
Mandurah Depot 6 20 Quarry Way, Greenfields
Joondalup Depot 12 2 Buick Way, Joondalup
The ATCO Gas Australia organisation consists of six (6) distinct business units and corporate services are provided by ATCO Australia with five (5) corporate service business units. ATCO Gas Australia and ATCO Australia corporate services organisational structure is illustrated in APPENDIX 1. ATCO Gas Australia and ATCO Australia key corporate services business units and statement of their key functions are defined in sections 3.1.2.2 and 3.1.2.3.
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3.1.2.2 ATCO Gas Australia Business Units The six ATCO Gas Australia business units are as follows: Operations which includes the following activities: • day-to-day operation and maintenance of the GDS and MGL; • emergency response; and • network monitoring and control.
Asset and Engineering Innovation which includes the following activities: • providing strategic direction for engineering innovation, GDS expansion, reinforcement, operation, setting a maintenance regime including development and implementation of the Asset Management Plan (AA4) 2014-2019 (AST PL00018)[95] to promote safe operation of the GDS; • modelling the GDS and assessing seasonal performance; • operational engineering and technical support, providing project planning and administrative functions together with engineering management; • GDS inspection and audit services; • managing development, review and revision of technical specifications and SWIs; • GDS design and design of meter/regulator/valve sets and PRSs; • Operations stakeholder and land management; • pursuing compliance with technical regulatory requirements; • delivery of ATCO Gas Australia training and competency assurance with respect to the construction, commissioning, operations, maintenance and decommissioning of the GDS; • development, reviewing and monitoring of the Safety Case, auditing of systems and processes, undertaking formal safety assessments and various legislative requirements; and • emergency response management, planning and training.
Construction which includes the following activities: • delivery of GDS construction, covering capital projects (growth and sustaining), new mains and services (new sub-divisions and sub-division in-fill), GDS replacement/upgrade, meterset and fabrication; • warehouse operations; • equipment calibration and maintenance; • high population density compliance and gas connection innovations projects; and • construction quality assurance programs (inspections and audit); and. • ATCO Gas Australia facilities construction projects.
HSE which includes the following functions:
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• delivering HSE communications including Safety Toolbox Meetings, Safety Focus Talks, Toolbox Notes and other safety communications; • investigating HSE incidents and implementing improvement initiatives; • developing HSE policies and procedures; and • monitoring and reporting of HSE KPIs. Regulatory which includes the following functions: • Managing regulatory requirements from the economic regulator • Ensuring compliance to economic regulatory requirements • Development of access arrangement submissions Customer Sales and Business Development which includes the following functions: • Engaging with customers for faults and emergencies • Communications with customers who have complaints and issues • Liaising with commercial and industrial customers to better meet their needs • business development and marketing; 3.1.2.3 Corporate Services Provided by ATCO Australia Pty Ltd Corporate services provided by ATCO Australia Pty Ltd applicable to this Safety Case are as follows: Human Resources which includes the following functions: • personnel administration, such as payroll, personal and industrial relations activities, corporate inductions; • management of HR policy and procedures; and • recruitment. Corporate Services and Legal manages the following functions: • legal support and expertise to assist ATCO Gas Australia with ensuring that its regulatory and operational objectives are carried out safely, efficiently and in compliance with the law; • contract preparation, negotiation and finalisation for ATCO Gas Australia; • economic regulatory compliance management; • supply chain and procurement functions; • Risk, Compliance and Internal Audit – managing corporate risk, compliance and audit activities, including insurance program; • Quality and Document Control – managing ATCO Gas Australia quality assurance and document control processes; • fleet and facilities (office and depot / non-network assets) management; • commercial contracts; and • relationships with ATCO Gas Australia stakeholders, employees, shareholders, customers, contractors, consultants and regulators.
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Business Development manages the following functions: • community engagement and internal communications; • corporate communications; • business development and marketing; and • support for Pipeline Operations stakeholder and land management. Information Technology manages the following functions: • ATCO Gas Australia’s information technology support and development functions; • ATCO Australia Pty Ltd.’s and ATCO Gas Australia’s interface with external information technology service providers. Finance manages the following functions: • financial management functions including financial accounting, accounts payable and receivable; • financial planning and investment; • retailer billing and gas haulage; and • economic regulatory compliance management.
3.1.2.4 ATCO Group Corporate Services ATCO Group (Canada) provides supplementary advice and guidance in finance, human resources, supply chain & procurement, information technology, real estate and insurance corporate services. Policy and Leadership 3.1.2.5 Leadership ATCO Gas Australia employs a KPI based system to set targets and achieve objectives which includes those relating to safety and health performance. Business Plans and Individual Position Descriptions detail how each individual ATCO Gas Australia employee is expected to contribute to the achievement of these objectives. 3.1.2.6 Vision and Values ATCO Gas Australia’s vision is to realise the full potential of its infrastructure, with natural gas recognised as a key and valuable energy solution for the people of Western Australia. As an organisation, in order to live up to this vision, ATCO Gas Australia has seven key values that all ATCO Gas Australia employees live by: Integrity – honest and ethical, treat others with fairness, dignity and respect. Transparency – clear about our intentions and communicate openly. Entrepreneurship –creative, innovative, and take a measured approach to opportunities, balanced with a long term perspective. Accountability –make good decisions, take personal ownership of tasks, be responsible for actions, and deliver on commitments. Collaboration –work together, share ideas, and recognise the contribution to others. Perseverance –perseverance in the face of adversity with courage, a positive attitude, and a fierce determination to succeed. Caring –care about the safety and wellbeing of consumers, employees and their families, communities, and the environment.
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ATCO Gas Australia’s continual focus is to deliver safe, reliable, consumer friendly, cost competitive and environmentally sustainable natural gas.
3.1.2.7 Policy The Health, Safety & Environment Policy (HSE PO00002)[96], and Risk Management Policy (RMT PO00001)[97] state the commitment of ATCO Gas Australia to occupational health and safety, and risk management. It is ATCO Gas Australia’s objective to demonstrate commitment to achieving a high standard, and continuously improving levels of health and safety, and risk reduction for their operations through the implementation of these Policies. The roles and responsibilities for implementation of the Risk Management Policy (RMT PO00001) are set out in the ATCO Australia POS Risk Management Framework (AA-RSK-FWK- 01)[98] and Risk Management Procedure (RMT PL00001 PR0002)[99], refer to section 3.5.1. The mechanisms for measuring ATCO Gas Australia’s Risk Management capability, and achievement of the objectives set out in the ATCO Gas Australia Risk Management Policy include: • regular monitoring of the organisation’s performance against its risk management treatment plans; • scrutiny of risks by ORMCC, HSSE committees and Dedicated Audit Director; and • appraisal of particular issues by Internal Audit.
3.1.2.8 ATCO Gas Australia Employees This Safety Case was developed in consultation with Management and ATCO Gas Australia employees with accountabilities or responsibilities defined within this Safety Case. The ATCO Gas Australia HSE Policy was developed by ATCO Gas Australia Management in consultation with ATCO Gas Australia employees through the HSE Committee – elected OHS representatives, and approved by the ATCO Australia Principal Operating Subsidiary (POS) Committee and has been implemented and made available to ATCO Gas Australia employees electronically for those with such access, and in hardcopy for those without. ATCO Gas Australia employees involved in the ATCO Gas Australia GDS Operation need to be aware of the Safety Case, HSE Policy and their responsibility for assuring the safety and health of themselves and others, the environment and GDS integrity. ATCO Gas Australia employees may obtain information on their responsibilities from: • controlled documents that form or are referenced within this Safety Case, that are accessible through DMS, ATCO Gas Australia vehicles’ manuals or Field Mobility Devices such as the Tough Book; • offer of employment; • employee inductions and corporate orientation; • ATCO Gas Australia provided training through the course of employment; • GDS Safety Case is accessible through ATCO Gas Australia’s intranet, or hard copies held within each office locations; • HSE Policy at visible locations within ATCO Gas Australia office locations ; and • Safety Toolbox meetings / Safety Focus Talks.
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3.1.2.9 ATCO Gas Australia Contractors (other than ATCO Gas Australia Employees) ATCO Gas Australia strives to integrate contractors where applicable using: • inductions, the means by which contractors are made aware of their responsibilities and obligations under the SMS; • training of contractors in ATCO Gas Australia’s safety standards such as SWIs, JRA and Take 5. The extent of the training, and by whom it will be delivered, is determined on a case by case basis and is often dictated by the duration of contracted work with ATCO Gas Australia; • procedures and SWIs required for Contractors engaged for Mains and Services work; • requiring participation of contractors in Safety Toolbox meetings / Safety Focus Talks; • including contractor HSE Representatives in the ATCO Gas Australia HSE Committee; and • monitoring contractor performance to detect deficiencies and the need for corrective action.
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Table 3-3: Key Position, or Group Responsibilities
Position Responsibilities President ATCO Gas • Authoriser of the Safety Case and responsible for ensuring Australia that ATCO Gas Australia Senior Management team is conversant and familiar with the legal requirements of the Safety Case and company compliance with those requirements. • Custodian of the Safety Case and has responsibility for managing safe ATCO Gas Australia GDS network operation through compliance with the SMS; strategic leadership and coordination of construction, maintenance, operation and emergency response activities, emergency response and for providing leadership in the management of change process.
General Manager Assets • Provides leadership for managing the network services, its and Engineering Innovation performance and planning; • Leads engineering services including design and implementation of assets and projects and drawing office quality assurance; • Provides leadership for technical compliance of the Safety Case and risk management for network operation and training competency assurance; • Ensures technical safety compliance and emergency response services are available; and
General Manager • Provides leadership for managing the expansion and Construction replacement construction activities on the ATCO Gas Australia network • Ensures compliance with project management requirements • Construction project management services; • Construction management services; • Construction audit and inspection services; • Construction activities; and • Warehouse and workshop management services.
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General Manager • Provides leadership for services (planned and Operations unplanned/reactive maintenance); • Plans the network faults response; • Provides leadership for gas utilisation inspection services and permit system; • Provides leadership for field maintenance services – planned and unplanned/reactive maintenance; and • Plans provision of emergency response service.
General Manager • Oversees the development of ATCOs economic regulatory Regulatory strategies and submissions including access arrangements
General Manager • Oversees the development of ATCO Gas Australia’s Customer Sales and strategic customer engagement strategies Business Development • Provides leadership for the Call Centre operations • Coordinates customer relations, business development and growth strategies
Senior Manager HSSE • Provision of HSSE services and advice to ATCO Gas Australia; • Manages health, safety (of personnel) and environmental risk and site inductions of ATCO Gas Australia employees and the provision of hazard and housekeeping inspections and records and conduct of tool box meetings; and • Conducts continual review and revision of ATCO Gas Australia network safe work instructions.
Manager Technical • Coordinating the implementation of the Safety Case; Compliance • Monitoring compliance with the Safety Case and relevant technical regulations; • Overseeing the performance of FSAs for the ATCO Gas Australia GDS Operation; • Liaison with relevant technical regulators in relation to the ATCO Gas Australia GDS Operation; • Custodian of the Emergency Response Management Plan (TCO PL00001)[100] and is responsible for maintaining a programme of emergency response exercises and training, in accordance with company and legislative requirements.
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Manager Asset Services • Provision of a safe, reliable network; operated and maintained efficiently to deliver gas; and • Development and implementation of asset management and maintenance strategies and the planning of network expansion to cater for current requirements and possible future growth.
Manager Engineering • Engineering design, maintaining technical integrity for the Services ATCO Gas Australia GDS network operation; • Project engineering and management, preparation of project management plans for network modification projects; and • Provision and maintenance of engineering and asset drawings for maintaining the ATCO Gas Australia GDS IBIS for internal and external use through the DBYD service.
Senior Manager Technical • Management of GDS technical specifications and Safe Work Services Instructions including development, review and revision. • Management of GDS training and competency assessment processes • Management of GDS construction, operations and maintenance inspection services • Management of systems and procedures for verifying integrity and application of GDS materials and equipment are fit-for purpose and meet approved standards (external and internal) • Liaison with EnergySafety on GDS technical issues
Manager High Density • Construction management services; Solutions • Construction audit and inspection services; and • Construction activities.
Capital Projects Manager • Construction project management services; (Growth) • Construction and maintenance workshop management services • Warehouse management services
Manager Construction • Construction project management services; Programs • Construction management services; • Construction audit and inspection services; and • Construction activities
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Manager New Mains and • Construction project management services, mains and Service services
Manager Replacement • Manage construction capital replacement projects Program Construction Quality • Supervise construction quality assurance and inspection Assurance Lead programs
Manager Operations North • Planning services (planned and unplanned/reactive maintenance); • Network faults response; • Field maintenance services – planned and unplanned/reactive maintenance (Perth metropolitan north); • GDS leakage survey program; and • As-required support for incident/emergency management and response.
Manager Operations South • Planning services (planned and unplanned/reactive maintenance); • Network faults response; • Field maintenance services – planned and unplanned/reactive maintenance (Perth metropolitan south and Albany region); and • As-required support for incident/emergency management and response. •
Regional Operations • Planning services (planned and unplanned/reactive Manager maintenance); • Network faults response; • Field maintenance services – planned and unplanned/reactive maintenance (Geraldton, Kalgoorlie, Bunbury, Busselton and Perth metropolitan for Facilities and Pipeline maintenance); and • As-required support for incident/emergency management and response; • Pipeline patrol, and CP activities; and • Managing planned and unplanned maintenance of pressure reduction, and metering facilities and high pressure steel pipelines.
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Manager Supply Chain, • Supply chain and procurement management system ATCO Gas Australia • Procurement of materials; and • Procurement of third party services.
Manager Network Control • Control Room covering scheduling of unplanned GDS maintenance (faults of incident response); and the Permit to Work System regarding opening, closing, recording and monitoring Permits; • Network metering and data management, covering GDS Telemetry (remote pressure and flow monitoring devices); meter reading, unaccounted for gas (UAFG) and GDS gas quality data monitoring and reporting; • Network maintenance planning and scheduling; and • Implementation of the Permit System.
ATCO Australia Risk • review whether the ATCO Australia POS, including ATCO Committee Gas Australia, has in place a current and comprehensive Framework and associated procedures designed to ensure that the identification and management of risks are effective • determine whether a sound and effective approach has been followed in managing the high/extreme risks
ATCO Gas Australia • provide strategic leadership and governance for the Operational Risk organisation’s management of risk, including reviewing Management and effectiveness of internal controls, and setting and approving Compliance Committee the organisation’s risk tolerance criteria • provide oversight of the organisation’s strategic and corporate risks, including prioritising the identified risks, reviewing and approving the Strategic and Corporate Risk Register, and monitoring progress of risk treatment plans • consider risks that have been escalated by the business including any treatments to mitigate adverse impacts and maximise positive business opportunities • provide strategic input into the development, implementation and evaluation of risk programs that support the implementation of the Risk Management Policy (RMT PO00001)
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Risk Owner is a person that has been given the authority to manage a particular risk and is accountable for doing so, in particular, the person is responsible for: • assessing risk against the organisations risk tolerance criteria in consultation with risk stakeholders to determine risk acceptance strategies (i.e. accept without treatment, treat, terminate) • determining the risk treatment actions • seeking resources / budget for risk treatment actions • monitoring their risks and risk treatment actions and conduct ongoing consultation and communication with risk stakeholders
Risk Treatment Action • implementing risk treatment actions in conjunction with risk Owner treatment stakeholders as defined by Risk Owner • monitoring risk treatment action implementation status • providing risk treatment implementation status reports to Risk Owner
Risk and Compliance • developing, implementing, reviewing and continuously Team improving the organisation’s risk management framework • coordinating and facilitating risk reviews at corporate and strategic level, divisional and business unit level, and for business cases and projects. • follow-up on status of risk treatment actions and report to management • collecting and analysing risk data to provide risk information to management • assisting ORMCC to determine the organisation’s risk tolerance criteria • providing enterprise risk management advisory services across the organisation
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Technical Compliance • coordinating the implementation of the Safety Case. Team • developing, implementing, reviewing and continuously improving the methodology for conducting formal safety assessments • coordinating and facilitating formal safety assessments • monitoring formal safety assessment risk treatment action status and providing status reports to management • providing technical safety and integrity risk advisory services across the organisation
HSSE Team • championing a risk management culture • coordinating the implementation of the HSE Management System. • facilitating in consultation with Risk Owners and Risk Treatment Action Owners, development of risk treatment actions in accordance with the organisations risk tolerance criteria to reduce risk to as low as reasonably practicable • providing HSE risk advisory services across the organisation, including in risk reviews and formal safety assessments.
Employees responsible for proactively identifying and analysing risks in their own areas, and manage and escalate these risks in accordance with the Risk Management Framework to achieve business objectives
3.1.3 Organisation and Responsibility 3.1.3.1 Structure APPENDIX 1 provides a high-level overview of the ATCO Gas Australia structure and Section 3.1.3.2 highlights the key positions with responsibility for Safety Case development, implementation, monitoring, auditing and management review. The ongoing success of the ATCO Gas Australia GDS network operation is dependent on persons involved in it complying with their personal duties of care and responsibility for safety, including those under relevant company policies and legislation. Company policies and legislation require ATCO Gas Australia personnel involved in activities relating to the ATCO Gas Australia GDS to assume responsibility for the following to ensure that they are fully informed of their obligations in relation to the Safety Case: • adhering to the requirements of the Safety Case; • their own safety and for following procedures, safe working practice codes, standards and regulations;
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• where required, contributing to development of safe systems and in particular involvement in risk assessments; • reporting hazardous conditions, potential hazards and incidents; • taking initial corrective action or response in the event of an emergency; and • undertaking tasks and duties as necessary to assist in the continual improvement of the SMS. 3.1.3.2 Resources, Roles and Responsibilities The outline of key positions and responsibilities of ATCO Gas Australia employees relevant to the Safety Case is provided in Table 3-3. The approval authority of each position is provided in the GDS Safety Case Approvals Matrix (TCO PR0012)[101]. Each ATCO Gas Australia employee has a Position Description that: • generally defines their supervisory responsibility, level of authority, tasks to be performed and other position duties; and • contains information outlining the qualifications, experience and competencies that are necessary or considered desirable for them to fulfil the requirements of the position.
3.2 Employee Involvement, Consultation and Communication The Safety Case was prepared in consultation with ATCO Gas Australia personnel, providing representation and input from both management and employee perspectives. ATCO Gas Australia employees, including management, are involved in key areas of safety and health management, specifically some or all of the following: • developing and reviewing procedures; • operational planning activities (e.g. pre-job meetings, Job Risk Assessment (JRA and Take 5); • Site and general inspections; • Gas distribution team inspections; • Safety Toolbox meetings / Safety Focus Talks; • design modifications; • review of new engineering designs and projects; • HSE Event investigation; • hazard and risk assessment / FSA workshops; • Hazard and Operability (HAZOP) studies; and • safety training initiatives. Employee involvement is via participation in: • Safety Toolbox meetings / Safety Focus Talks; • hazard and risk assessment/FSA workshops • pre-job meetings;
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• JRAs and Take 5; and • scheduled and unannounced site and general inspections. Employees are encouraged to take an active role in training development initiatives identified through one on one meetings with their leaders (i.e. Managers, Supervisors, and Team Leaders). ATCO Gas Australia employees also participate in the development of safety objectives via HSE Committee Meetings, which serve as a means for employees to suggest changes or modifications to policies and procedures and raise issues that relate to their safety and health or safe ATCO Gas Australia GDS network operation, via their Safety and Health Representatives.
3.2.1 Pre-Start Meetings / Post Job Debriefs Typically prior to commencement of work, pre-start meetings are held and the Take 5, or JRA and other risk and procedural documentation such as Major Work Permits are prepared and or reviewed. Pre-start meetings are held on site during performance of large scale maintenance activities, construction activities, subdivision work or emergencies such as major outages or water in the Main. This involves staff at the incident site discussing relevant site specifics, repair methods and safety aspects such as traffic hazards, other utilities and environmental issues. Pre-start meetings are also held as needed in meeting rooms, at the rear of the depot or at supervisors’ offices before field staff depart daily to explain technical aspects or specific safety or site environmental concerns. More detailed meetings are held when they are considered to be required, such as, when working under a Major Work Permit when no standard procedure exists. In addition Hazard Identification (HAZID) Studies are conducted before constructing assets which are subject to the requirements of AS 2885.
3.2.2 Safety Toolbox Meetings / Safety Focus Talks Safety Toolbox meetings / Safety Focus Talks are nominally held once a month at the Jandakot and Wangara Depots to focus on specific health and safety issues - such as lifting, slips and trips, workplace injuries and incidents, and any recent hazards identified on the network. They allow workers, safety professionals and managers to discuss risks, and strategies for dealing with them. These talks are intended to encourage health and safety focus, and demonstrate the relevance of specific topics to particular jobs. Safety Toolbox meetings / Safety Focus Talks are intended to be concise and relevant, covering current issues, providing safety updates and encouraging safety awareness. Employee ideas and suggestions for future topics are also sought. Attendance at these sessions by employees is encouraged, and records of attendance to these sessions are maintained and checked.
3.2.3 HSE Committee Meetings The HSE Committee contains members from various work groups, including ATCO Gas Australia employees and contractors. The purpose of the HSE Committee is to promote a ZERO HARM culture by creating a “don’t walk by” attitude where hazards and issues are proactively identified, rectified and communicated in a timely manner for the health and wellbeing of everyone. The HSE Committee is scheduled to nominally meet 12 times per year, and its functions include:
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• review trends in hazard reports, injuries and incidents, and address HSE issues raised which have not been resolved by individual Safety and Health Representatives; • escalate any issues that cannot be resolved in accordance with HSE Issue Resolution (HSE PR0015)[102]; • circulate key issues from HSE Committee meetings to ATCO Gas Australia employees; • review HSE requirements and changes in the workplace prior to general implementation; and • review significant Events and Hazards.
3.2.4 Safety and Environment Initiatives Plan (SEIP) Committee Meetings The annual Safety and Environmental Initiatives Plan (SEIP) outlines initiatives being devoted and implemented by the SEIP Committee with a focus on works performed within ATCO Gas Australia in order to: • establish a ZERO HARM culture; • promoting a ‘Don’t Walk By’ philosophy; • eliminate employee work related injuries and illnesses; • improve asset safety and asset operations; • reduce personal and financial losses; and • achieve environmental excellence.
3.2.5 SafetyGrams, Toolbox Notes, EnviroGrams and Technical Notices SafetyGrams may be published as a result of a GDS or HSE incident or a near miss experienced by ATCO Gas Australia or contractor, or as a result of incidents, information or other promotions that are provided by operators of similar facilities, government regulators etc. EnviroGrams are used from time to time to provide information on environmental related issues within ATCO Gas Australia and / or Contractor groups. Toolbox Notes are issued where there is a change in safe work instructions, relating to a Prescribed Activity or to provide additional information regarding a procedure or safe work instruction. Technical Notices are issued to provide technical information about tools and equipment used within the business. These include, but are not limited to, tool improvements or modifications, tool recalls due to faults or new tooling available for use.
3.2.6 Communication of Statistics Monthly HSE and GDS incident statistics are posted on various noticeboards in the workplace and these statistics are also discussed at management, Safety Toolbox Meetings / Safety Focus Talks, monthly HSE Committee meetings, bimonthly Contractor Meetings and monthly Supervisor Meetings. The details and status of corrective actions arising from audits are communicated to relevant personnel for consultation and close out. Audit reports are accessible via DMS.
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3.3 Incident Reporting
3.3.1 Incident Reporting and Investigation Notifiable Incidents as defined by Regulation 43 of the GSSS Regulations are reported by the Control Room to the DES in accordance with Notifiable Incident Reporting (TCO PR0003)[103]. To meet the requirements of Regulation 47 of the GSSS Regulations, ATCO Gas Australia submits to the DES weekly and monthly bulletins providing reports of Gas Incidents as defined by Regulations 42, which includes Notifiable Incidents as defined by Regulation 43. Refer to Work Instruction Weekly Bulletin (CTR WI007)[104]. Notifiable Incidents that also require investigation and report in accordance with Regulation 44 of the GSSS Regulations are investigated by the Manager Technical Compliance, or nominated delegate, in accordance with Notifiable Incident Reporting (TCO PR0003). The investigation report is to be reviewed by the General Manager Engineering and Construction or General Manager Operations, approved and submitted to the DES by the Manager Technical Compliance or delegate. Where the Notifiable Incident results in injuries to ATCO Gas Australia personnel and, or contractors, or harm to the environment the injury or harm is also to be reported in accordance with HSE Hazard and Incident Notification (HSE PR0017)[105] to the Senior Manager HSSE, or nominated delegate and investigated in accordance with HSE Event Investigation, Corrective and Preventative Action & Close Out (HSE PR0018)[106]. Notifiable Incidents for which required and investigation and preparation of a report are to be stored, retained, and disposed of in accordance with the requirements of Records Management Procedure (AA-GOV-PRO-001)[107].
3.3.2 Action Tracking Notifiable Incident corrective actions identified through incident investigation and reporting are managed through to close-out as follows: • In accordance with GDS Risk Register (Action Tracking) (TCO PR0008)[108], using Technical Compliance Document Register (TCO RG0003)[109] as the action tracking spreadsheet. • In accordance with HSE Event Investigation, Corrective and Preventative Action & Close Out (HSE PR0018) where there has been injuries to ATCO Gas Australia personnel and, or contractors, or harm to the environment the injury or harm using the ERP Netweaver Business Client HSE Event Management and Reports incident management system.
3.3.3 Communication Completed Hazard/Incident Reports and Investigations are available to employees via ATCO Gas Australia’s incident management system which is recorded in ERP EHS. SafetyGrams / Toolbox Notes / Technical Notices are prepared, issued and distributed to employees involved in activities related to the ATCO Gas Australia GDS Operation, to share lessons learned from internal HSE investigations and external safety information received from time to time from regulatory authorities and other operators. Where relevant they are also to be distributed to contractors and sub-contractors for information.
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Incidents are discussed at HSE Committee Meetings, with particular attention given to Category 1 - ‘notifiable incidents’, as defined in the Emergency Response Management Plan (TCO PL00001), and status of corrective actions.
3.4 Objectives and Key Performance Indicators
3.4.1 Objectives The ATCO Gas Australia GDS Safety Case and Health, Safety & Environment Policy (HSE PO00002) sets goals in order to achieve the vision of providing a safe and healthy workplace free of occupational injury and illness, which operates to minimise the risk to employees, the public and the environment. ATCO Gas Australia aims to achieve these goals via performance objectives including: • identifying, assessing and controlling hazards and risks to an acceptable level, or Intermediate and as low as reasonably practicable (ALARP); • setting, monitoring and communicating meaningful performance measures to employees and stakeholders; • actively identifying and implementing opportunities to improve GDS safety, integrity and HSE outcomes; • recognising and rewarding innovation in HSE; • providing appropriate training and forums to communicate safety processes, initiatives and issues to employees and contractors; establishing and maintaining a comprehensive SMS in accordance with the requirements of AS/NZS 4645 and AS2885 Part 1 and 3.
3.4.2 Key Performance Indicators (KPIs) The performance of systems and processes implemented for design, construction, operation and maintenance of the ATCO Gas Australia GDS are regularly monitored and reported within ATCO Gas Australia as part of overall performance reporting. A variety of KPIs relating to health, safety and the environment, and performance standards relating to the integrity of the ATCO Gas Australia GDS have been set. KPIs that are a part of the Safety Case are those KPIs detailed in Table 10 of the Asset Management Plan (AA4) 2014-2019 (AST PL00018):
3.4.3 Performance against KPIs Performances against the Safety Case KPIs are used to monitor the success of the SMS and targets set in the Asset Management System. Performances against Safety Case KPIs defined in Table 3-4 are reported monthly in the ATCO Gas Australia Monthly Report and are included in the KPIs reported annually to the ERA. Failure to meet Safety Case KPIs not defined in Table 3-4 is reported by exception.
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Table 3-4: KPI Performance reported monthly Key Performance Indicators Reliability KPIs: Minutes per customer lost due to unplanned supply interruptions; or System Average Interruption Duration Index (SAIDI) Supply interruptions per 1000 customers; or System Average Interruption Frequency Index (SAIFI) Network Condition KPIs: Defects (leaks) per km of Main Unaccounted for Gas (UAFG) as % of throughput Third Party Damage Prevention KPIs: Broken Mains per annum Broken Services per annum Operational Response KPIs: Attendance/response to Broken Mains and Services within KPI response time Attendance/response to No Gas Commercial/Domestic within KPI response time Network Capacity KPIs: Number of Network “Low-Pressure Alarm” Events per annum (not contributed to by third party actions)
3.5 Risk Management ATCO Gas Australia’s risk management framework is established at corporate level (ATCO Australia Pty Ltd) and is maintained by Corporate Services and Legal. For operational situations there are specialist groups within ATCO Gas Australia for implementing the risk management processes required of applicable standards – Technical Compliance, Technical Services, Asset Services, HSE, and Engineering Services. Where new additions to the GDS can change the risk the project management processes are to minimise the risks that maybe added.
3.5.1 Risk Framework ATCO Gas Australia commits through the ATCO Australia POS Risk Management Framework (AA-RSK-FWK-01) and Risk Management Procedure (RMT PL00001 PR0002) to adopting an enterprise-wide approach to risk management to achieve sustainable growth in a safe and environmental responsible manner while enhancing shareholder value and maintaining operational excellence. ATCO Australia POS Risk Management Framework (AA-RSK-FWK-01) provides commitments to this objective through implementing, measuring and improving a risk management framework. Resources including appropriate education and training in risk management are part of this commitment. ATCO Australia POS Risk Management Framework (AA-RSK-FWK-01) has broader risk management implications than the requirements of this Safety Case. Specifically for this Safety Case, ATCO Australia POS Risk Management Framework (AA-RSK- FWK-01) and Risk Management Procedure (RMT PL00001 PR0002) commits to:
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• systems and procedures in line with the standards required for this Safety Case; • risk tolerance thresholds which implicitly include the management of, or reduction of risk to an acceptable level, or to Intermediate and demonstration that risk is ALARP; and • embedding risk management into all levels of ATCO Australia and ATCO Gas Australia’s business, which for this Safety Case is achieved through the processes described through the remainder of Section 3.5; and • follows the process provided by AS/NZS ISO 31,000 Risk management - Principles and guidelines[110]: see Figure 3-1.
Figure 3-1: Risk Management Process
ATCO Gas Australia’s risk tolerance criteria is documented in ATCO Australia POS Risk Management Framework (AA-RSK-FWK-01) and ATCO Gas Australia Risk Management Matrix (RMT PL00001 PR0002 WI001)[111] and is in line with AS/NZS 4645 and AS 2885. Risk tolerance provided in the framework is based on a risk ranking where: • Extreme and High risks are intolerable and RMAPs must be developed and put in place to reduce risk to Intermediate or lower; • Intermediate risk may only be considered tolerable when risk re-evaluation has confirmed the risk rank, it is not reasonably practicable to modify the risk threat, frequency or consequence to reduce risk to Low or Negligible and it is demonstrated risk is ALARP; and
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• Low and Negligible risks are accepted risks and there is no requirement to further reduce risk. The requirements for demonstrating whether or not an Intermediate risk is ALARP is defined within Technical Compliance Risk Management Guideline (TCO GL0001)[112] and involves: • identifying options for further risk reduction; • then, determining practicality and the level of risk reduction achieved for each option; and • review and approval of risk reduction measure(s) selected for implementation, or otherwise rejected.
3.5.2 Corporate Risk Management The Operational Risk Management and Compliance Committee (ORMCC) provides oversight of the risk management framework across ATCO Gas Australia, with the corporate risk management processes being managed by the Risk and Compliance unit of ATCO Australia Pty Ltd. The corporate risk management processes involve maintaining the Corporate Risk Register which documents those risks across ATCO Gas Australia’s business that are of a strategic or corporate nature. The threshold for this review of the range of risks differs from the governing legislation and standards for this Safety Case. This process results in the risks ranked in “Intermediate-12” and higher ranked in accordance with ATCO Gas Australia Risk Management Matrix (RMT PL00001 PR0002 WI001) being reviewed on a quarterly basis by the ORMCC.
3.5.3 Technical Compliance Technical Compliance manages the risk management processes required by AS/NZS 4645 and AS 2885 to deliver Formal Safety Assessments (FSAs). The framework and process for these FSAs, based on the requirements of AS/NZS ISO 31000, are included in Technical Compliance Risk Management Guideline (TCO GL0001). The FSA requirements of the standards for the GDS are being achieved through: • Safety Management Studies of the Class 300 and 600 pipelines; • Hazard and Operability Study (HAZOP) of pressure reducing and metering facilities with inlet pressures greater than 1,900kPa; and • Network FSA of the remaining assets within the GDS.
3.5.4 Formal Safety Assessment Development The FSA description, Section 4, has been collated as a summary of the risks identified through the various risk assessments. This summary addresses the significant risks, and controls working to prevent, minimise or mitigate those risks. For this Safety Case significant risks are risks that have been assessed as Intermediate or higher. Residual risk is the level of risk with the current controls in place. The risk control measures applied to control significant risks to an acceptable level, or Intermediate and ALARP are referred to as significant controls. Figure 3-2 represents the various assessments that are referred to as Formal Safety Assessments (FSA).
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ATCO Gas Australia Gas Distribution System Safety Case Formal Safety Assessment
Risk Register Technical Compliance Document Register (TCO RG0003)
Network and Prescribed Activity Based Formal Safety Assessments Network FSAs • • Natural Gas Network FSA Construction • Albany LPG Network FSA • Commissioning • Decommissioning • Operations AS 2885 Safety Management Study • Maintenance / Risk Assessment • Management of Change • Deviation from prescribed AS/NZS 4645 requirements
Hazard and Operability Semi-quantitative Risk (HAZOP) Studies Assessment • Mains Replacement Prioritisation (MRP) software tool AS/NZS 4645 Threats and Controls Hazard Identification and Risk • Major Gas Supply Interruption Assessment Analyses FSAs • AS 2885 Safety Management Studies (Fatality risk)
Figure 3-2: FSA Sources
3.5.5 Safety Management Study Safety Management Study is a structured threat assessment required by, and the process specified within, AS 2885. For the GDS this is required for operational pipelines with MAOP >1900kPa (Class 300 and 600) and the design of new pipelines MAOP 1050kPa to 1900kPa (Class 150). This study provides consideration by location of the different threats that may impact the pipeline. Those threats are considered for potential impacts on the pipeline which may in turn result in harm to people, gas supply or the environment. The Safety Management Study is to be conducted in accordance with AS 2885. Where the assessment determines that failure is possible, the qualitative risk assessment and development
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of risk treatment actions to reduce risk to an acceptable level, or Intermediate and ALARP is conducted in accordance with ATCO Australia POS Risk Management Framework (AA-RSK- FWK-01) and ATCO Gas Australia Risk Management Matrix (RMT PL00001 PR0002 WI001). The records of Safety Management Studies are standalone reports.
3.5.6 Network FSA Network FSAs consider the risks that impact people, the environment and gas supply due to the GDS itself and Prescribed Activities. Refer to Figure 3-2 where Network FSAs are a collection of assessments. Individual FSA involve preliminary discussions, a workshop and close-out to confirm any actions. The existing Network FSAs are reviewed at least every five (5) years and existing or new FSAs are conducted when the nature of the risk is changed due to new: • projects, • materials or components; or, • work methods. The risk management process involves: • Establishing context, determined prior to the workshop and documented in the Terms of Reference, • Risk Assessment, the identification, analysis and evaluation of risk in the workshop and documented in the Risk Register. • Treating Risk, the determination of actions to address risks deemed intolerable which begins within the workshop and may require ongoing development prior to finalising the FSA and documented in the Risk Register and tracked in the Action Tracking Register? The record of each Network FSA conducted for the GDS are standalone reports comprising the risk register and agreed upon actions.
3.5.7 HAZOP HAZOP is to be conducted on pressure regulation and metering facilities with inlet operating pressure of 200kPa or above. HAZOP provides a systematic guideword driven process to identify deviations from the anticipated design that may result in hazardous situation and/or operational difficulties. The HAZOP process included in Technical Compliance Risk Management Guideline (TCO GL0001) is based on the AS IEC 61882—2017 Hazard and operability studies (HAZOP) – Application guide[113]. Any causes for potential GDS hazards are considered in the Network FSA. HAZOPs are facilitated by Technical Compliance, specialist Engineers or contractors and are prepared with expertise from design and operations personnel. The records of HAZOPs are standalone reports.
3.5.8 Semi-Quantitative Risk Assessment Semi-Quantitative Risk Assessment (SQRA) is utilised by ATCO Gas Australia where suitable frequency and consequence data is available to justify assessed levels of risk. Data used for frequency analysis has been sourced from:
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• Local and Australian experience; and • Data or research collated by international industry bodies, such as the United Kingdom On-shore Pipeline Operators’ Association (UKOPA). Where the output of SQRA provides a consequence probability in terms of events per year, the numerical frequency is mapped to ATCO Gas Australia’s qualitative Risk Matrix as shown in Table 3-5. Risk tolerance and treatment of risk ratings resulting from SQRA is then assessed in accordance with ATCO Gas Australia’s Risk Acceptance Criteria documented within AA-RSK- FWK-01 ATCO Australia POS Risk Management Framework[98] . The quantitative ranges selected against each qualitative descriptor was determined by taking into consideration ATCO Gas Australia’s qualitative definitions, and guidance on individual risk tolerance stipulated within BSI Standards Publication PD 8010-3:2009+A1:2013 Pipeline Systems - Part 3: Steel Pipelines on Land - Guide to the Application of Pipeline Risk Assessment to Proposed Developments in the Vicinity of Major Accident Hazard Pipelines Containing Flammables. In the absence of Australian quantitative risk tolerance criteria applicable specifically to natural gas transport, this guidance document was deemed applicable due to its application to natural gas transmission pipelines in a distribution context and citing of UK Health and Safety Executive risk tolerance criteria. Semi-quantitative methodology has been applied by ATCO Gas Australia as part of the following assessments: • Mains Replacement Prioritisation (via proprietary software); • AS2885 Safety Management Studies; and • Gas supply interruption assessments.
Table 3-5 – Qualitative frequency mapped to quantitative value
Qualitative Quantitative Value Descriptor
Frequent One or more per year (≥ 1pa)
Occasional One per year to one in a hundred years (1 to 10-2pa)
Unlikely One in a hundred years to one in ten thousand years (10-2 to 10-4 pa)
Remote One in ten thousand to one in a million years(10-4 to 10-6 pa)
Hypothetical Less than 1 in a million years (<10-6 pa)
3.5.9 Risk Treatment Action Tracking Risk treatment for any of the assessments undertaken by Technical Compliance that involves actions to be completed over time is tracked through to completion by Technical Compliance using the tracking register, Technical Compliance Document Register (TCO RG0003). The process for tracking the individual risk treatment actions, known as Risk Management Action
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Plans (RMAPs), to close-out is documented in GDS Risk Register (Action Tracking) (TCO PR0008). The action tracking process involves regular, typically monthly, meetings between Technical Compliance and RMAP owners to gather updates and evidence upon close-out. Action statuses are updated within the GDS Risk Register as comments.
3.5.10 Health, Safety and Environment (HSE) HSE manages ATCO Gas Australia’s occupational safety, health and environmental risk management processes. For the purpose of this Safety Case, HSE supports the risk management processes to provide for the safety of people, minimising damage to property, inconvenience, or other detriment as a result of conducting Prescribed Activities (the intent of Regulation 18(1) of the GSSS Regulations). HSE’s function for the purpose of this Safety Case includes: • conducting or reviewing new Hazardous Materials risk assessments; • reviewing quality of the JRAs and Take 5s; and • conducting plant and equipment risk assessments that maybe used in conjunction with Prescribed Activities.
3.5.11 AS 4645 Activity Risk Assessments Where a Procedure defines the process and steps for conducting Prescribed Activities, the risks associated with these activities are assessed. AS 4645 Activity Risk Assessments are conducted with the participation of Operations and, or Engineering and Construction personnel that work to the requirements of the SWI.
3.5.12 Chemical Risk Assessments Chemicals that are utilised by ATCO Gas Australia are subject to the Chemical Management Guideline (HSE GL0002)[114]. This requires chemicals being used within ATCO Gas Australia for the first time, including chemicals used on the GDS, to undergo risk assessment if the chemical is assessed a ChemAlert moderate (amber) or high (red) health hazard. The assessment is either conducted or reviewed by HSE.
3.5.13 Job Risk Assessments Prescribed Activities are subject to a Pre-task Hazard Assessment Process (HSE PR0025 WI001)[115] – either a JRA or Take 5. Personnel who physically undertake the work are involved in the completion of the assessment. The assessment is then reviewed for quality by HSE. A Take 5 is considered sufficient where there is an SWI in place for GDS Prescribed Activities. However, if the Take 5 identifies any of the following, a JRA is required: • hazards that remain inadequately controlled; • lack of SWIs / procedures that address the Take 5 identified hazards associated with the task to be performed; or • significant deviations from existing SWIs / procedures, with the potential for unidentified or inadequately controlled hazards.
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3.5.13.1 Pre – task Hazard Assessment ‘Take 5’ A Take 5 is a pre-task hazard assessment requiring the person(s) who is (are) to do a task to stop and ‘Take 5’ minutes to think through the task, identify hazards, implement identified controls and then complete the task safely. A Take 5 shall be conducted: • prior to commencing a task; • during the task if there is a change in the task scope or work environment from what was assessed prior to the task commencing; and • if new hazards are identified.
3.5.13.2 Job Risk Assessment (JRA) When conducting non-routine work that is not covered by Standard Operating Procedures, a JRA is to be conducted rather than a Take 5. The JRA process involves: • breaking the job down into discrete steps; • identification of hazards associated with each step of a job, and control measures to be put in place to eliminate or reduce the risks to people and the environment and acceptable level, or Intermediate and ALARP; • continual monitoring of the work environment for any new hazards arising, and reviewing and updating the JRA where this occurs; • the completed JRA is to be documented on the Job Risk Assessment (HSE PR0025 WI001 RF02)[116] or contractor’s equivalent; • the JRA is to be retained within the job file and a copy attached to each relevant work procedure for the job; and • once the job is completed, the JRA is reviewed by the HSE team to check that no other factors were introduced that could adversely affect safety of personnel or cause damage to the environment. This process is intended to promote continual improvement of work practices.
3.5.14 Work under Permit to Work System Non-routine works, including hot works that are not covered by an approved SWI require a Major Work Permit to be prepared and authorised prior to commencement of the works. Before permit approval can be obtained the risks need to be identified and controlled in accordance with the JRA process (refer to Section 3.5.13). Refer to Section 3.6.2 for a detailed description of the Permit to Work System (TCO PR0007).
3.5.15 Project Risk Management Project risk management for Prescribed Activities conducted under a PMP are to be conducted in accordance with Project Management Plan (ENS PL00002), and Project Risk Management (ENS PR 0001 WI001)[117]. Where project threats are required to risk assessed, the risk assessment is to be conducted in accordance with ATCO Australia POS Risk Management Framework (AA-RSK-FWK-01) and Risk Management Procedure (RMT PL00001 PR0002).
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3.6 OPERATIONAL PROCEDURES
3.6.1 Description ATCO Gas Australia uses operational procedures, which function at several levels, to facilitate the safe, efficient, and environmentally responsible operation of the ATCO Gas Australia GDS and include: • Permit to Work (PTW) System; • Procedures; • Guidelines; • Work Instructions; and • SWIs.
3.6.2 Permit to Work System Permit to Work System (TCO PR0007) defines the systems and procedures for managing risk associated with high risk and non-routine activities to assure inherent and introduced risks are controlled to an acceptable level. The PTW System identifies levels of activity each of which requires a distinct action prior to their commencement as defined in Network Control Permit (TCO PR 0007 WI004)[118]. This includes: • work requiring Verbal Notification to the Control Room, or Planning Department (refer Section 3.6.2.1); • work requiring a Minor Work Permit (refer Section 3.6.2.2); • work requiring a Major Work Permit (refer Section 3.6.2.3); • work requiring entry into a Confined Space requiring a Confined Space Permit (refer Section 3.6.2.4); • work requiring Deep Excavations (refer Section 3.6.2.5); and • work requiring Hot Work (refer Section 3.6.2.6). The Control Room keeps a register of work conducted using the PTW System and issues a permit number to the person responsible for conducting the work (Refer Register of Work Permits and Verbal Notifications (TCO PR0007 WI004 RF03)[119]. 3.6.2.1 Verbal Notification As defined in the PTW System, Verbal Notification to the Control Room or the Planning group is required for specified routine work for which a standard authorised work procedure or instruction does exist but where the work may pose an increased risk to the ATCO Gas Australia GDS integrity. Verbal Notification is to the Control Room, unless the work involves routine work being undertaken by ATCO Gas Australia’s Facilities Maintenance Department (which may also go to the Planning group). The activity must not commence until the Control Room or Planning has been notified and issued an authorisation to commence.
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3.6.2.2 Minor Work Permit Requests for a Minor Work Permit are made via completion of the Minor Work Permit Form (TCO PR0007 WI004 RF01)[120] and submitted for approval to the relevant manager; Managers Operations – North / South, Manager Network Control, Manager Construction Service Delivery, or Manager Engineering Services, or their delegate. A copy of the approved permit is submitted to the Control Room so that the permit can be opened on site. 3.6.2.3 Major Work Permit A Major Work Permit is required when carrying out non-routine work that is not covered by an authorised standard procedure. For a Major Work Permit, the Supervisor or representative completes the Major Work Permit Form (TCO PR0007 WI004 RF02)[121] and submits the Major Work Permit for approval to the: • Manager Engineering Services or Senior Manager Technical Services (or delegate); • Manager Network Control (or delegate); and • A functional manager from within Capital Infrastructure or Operations. The authorising signatories are responsible for assessing non-routine work procedures and assessing the impact upon the ATCO Gas Australia Network prior to authorising the Major Work Permit. A copy of the authorised permit is to be submitted to the Control Room so that the Permit can be opened on site. 3.6.2.4 Confined Spaces Below ground valve pits or other similar enclosed or partially enclosed structures (e.g. shafts, tunnels, etc.) that have been assessed as being a Confined Space in accordance with the procedure Confined Space Entry (TCO PR0007 WI001) are to be entered in the Confined Space Register (TCO PR0007 WI004 RG01)[122] in accordance with Confined Space Entry procedure and the form Confined Space Entry Permit (TCO PR0007 WI001 RF01)[123]. ‘Spaces’ that may be a Confined Space are to be assessed prior to entry to ascertain if the ‘space’ is a Confined Space, by using the form Confined Space Initial Assessment (TCO PR007 WI001 RF02)[124]. Identified Confined Spaces that are permanent ATCO Gas Australia structures (excludes excavations) are to be registered in the ATCO Gas Australia Confined Space Register and entry into the Confined Space is to be in accordance with Confined Space Entry and Confined Space Permit. The ATCO Gas Australia Confined Space Register is located in DMS. 3.6.2.5 Deep Excavations ATCO Gas Australia creates excavations on a daily basis to gain access to below ground assets. Excavations can vary in depth depending on the location of the gas asset. The Deep Excavation Permit acts as a control for any excavations below 1.5m deep. Personnel have to complete a permit in accordance with Deep Excavation (TCO PR0007 WI002)[125]. 3.6.2.6 Hot Work ATCO Gas Australia performs tasks that are classed as hot works including drilling, welding and grinding. When hot works is conducted, a Hot Work Permit is required in accordance with TCO PR0007 WI003 Control of Hot Work[126]. This permit ensures that hot work is conducted in a safe manner.
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3.6.3 Procedures, and other relevant documents Operations, Maintenance, and Engineering personnel, as well as personnel from other process areas, require procedures, work instructions, and SWI to provide guidance on how tasks are to be undertaken safely and consistently. ATCO Gas Australia defines a “Procedure” (refer Document Control Procedure (QLT PR0001)) as a document that specifies the way in which an activity or process is carried out to meet the company’s policies. A list of process areas are shown in Table 3-6.
Table 3-6: Process Area Procedures Abbreviation Process Area Abbreviation Process Area Abbreviation Process Area Project AST Asset Services INS Inspection PMM Management Land CCT Call centre LNM PRO Projects Management COM Commercial LOG Logistics QLT Quality Market CTR Control Room MSR REG Regulatory Affairs Services Corporate Network COA NCN RMT Risk Management Affairs Construction Engineering Network Technical ENS NCO TCO Services Control Compliance Network FIN Finance NOP TRN Training Operations HSE HSE OPS Operations Human HRS PLN Planning Resources
3.6.4 Safe Work Instructions (SWI) SWI are documented instructions on how ATCO Gas Australia employees and contractors are to perform Prescribed Activities on the ATCO Gas Australia GDS, to reduce associated risks an acceptable level, or Intermediate and ALARP. Personnel are required to conduct Prescribed Activities in accordance with the relevant SWI(s) and consider requirements of the PTW System (refer Section 3.6.2). SWI detail specific requirements, including types of safety and support / specialised equipment and tools, typical hazards, risks and controls to be considered, specific personnel requirements, mandatory and “optional” personal protective equipment, environmental considerations, approvals and permits to enable tasks to be performed safely with associated risks reduced demonstrably to ALARP. SWI also refer users to Training Records (for both ATCO Gas Australia employees and Contractors) to verify whether personnel are competent to undertake activities, or use tools or equipment, described in them. Where the Prescribed Activity also matches the definition of “high risk construction” work, as defined in the Occupational Safety and Health Regulations 1996, the SWI also describe how to safely perform the high risk construction work. Refer to section 3.5.11 for the requirements for SWI risk assessments. SWI have been developed to cover identified Prescribed Activities under the following categories:
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Table 3-7: Summary of ATCO Gas Australia SWI by general area or type of activity General Nature of Typical activities covered by (suite of) SWI documents Prescribed Activity AN – Analysis Analysis equipment and sampling including sampling of LPG and NG. CO – Construction ATCO Gas Australia construction activities. EX – Excavate Excavation and backfilling requirements including the safety requirements in relation to different soil types and shoring of excavations. Refer to Shoring of Excavations (SWI EX 003)[127]) for more information on shoring, benching, and battering. FERU – Field Emergency Field Emergency Response Unit which is used in emergency situations. Response Unit FI – Installation of Fitting Installation of Fittings. FS – Flow Stopping Various flow stopping techniques. GE – Gas Escapes Attendance to reported gas escapes, locating the source and the criteria for attendance by Field Emergency Response Unit (FERU). HSE – Health, Safety and Health, Safety and Environment tasks. Environment IN – Inspection Class G installation inspection and tightness testing of consumer gas installations. JT – Jointing Techniques Jointing plastic pipe, e.g. PE butt and electrofusion jointing and uPVC jointing. LPG – Liquified Petroluem Activities in relation to the Albany LPG Storage Facility such as delivery, Gas maintenance and checks. MA - Maintenance Maintenance of isolation valves and other specific maintenance activities. MRA – Meter and Range of specific meter and regulator activities. Regulator Activity MW – Maintenance of a range of gas distribution equipment, including OPSO Mechanical/Workshop devices. RT – Repair Techniques Repair of Mains and Services. SM – Systems Monitoring This suite is still to be finalised and covers the installation and maintenance of data logging equipment. SSU – Site Set Up Safety in relation to setting up the work site, such as the use of traffic management, barricading, working in the vicinity of overhead power lines, and location of underground utilities. ST - Steel Activities to be performed on steel Pipelines including CP activities, Pipeline patrol, welding, hydrostatic testing and other specific activities. TE – Tools and Equipment Equipment e.g. gas detectors, volt stick, continuity bonding and residual current devices.
SWIs have been developed on the basis of identifying known hazards which ATCO Gas Australia employees and contractors may be exposed to, the associated risks, and control measures to be implemented. When ATCO Gas Australia employees and contractors attend site to perform Prescribed Activities and, or high risk construction work they are further required to conduct a task specific JRA / Take 5 (refer to Section 3.5.13).
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3.7 Employee Selection and Training Work on the ATCO Gas Australia Network is to be either undertaken directly or supervised by ATCO Gas Australia, using established systems and procedures. The legal obligations under the ‘duty of care’ that apply to ATCO Gas Australia employees are applicable to any contractor or visitor that has permission to work on the ATCO Gas Australia Network.
3.7.1 Staffing Arrangements Staffing levels are determined during the development of strategic and business plans which are based on business needs. Staffing levels are reviewed in order to satisfy ongoing business requirements, including safe operations. It is the responsibility of managers to assess the resource needs of their team or section, and to advise their managers of any need to recruit or retain adequate numbers of suitably skilled personnel.
3.7.2 Employee Selection Recruitment and selection processes are employed by ATCO Gas Australia to source competent applicants to fulfil business requirements in accordance with Recruitment & Selection (HRS PR0004)[128]. The principles of equity and merit apply to recruitment and promotion practices. Employees are selected using the process described in the procedure Respect in the Workplace Policy (AA-HR-PO-027)[129], which is available under Policies and Procedures Human Resources on the ATCO Gas Australia Intranet. The process can be summarised as follows: • Human Resources, together with the appropriate line manager determine the responsibilities, qualifications, and skills and experience considered necessary to effectively execute the work and these details are recorded in a Position Description • a selection panel assesses applicants against the requirements of the Position Description; • applicants offered a contract of employment are required to participate in medical assessments and reference checks and may also be required to participate in a psychological assessment; and • once a preferred candidate is identified, an offer of employment is made and, if accepted, the appointment is made. New employees are required to undergo induction training specific to the requirements of their position and work environment/location.
3.7.2.1 Employee Health and Safety Records New employees involved with the operation and maintenance of the ATCO Gas Australia GDS are required to participate in a pre-placement medical test that may include one or all of the following types of testing, as appropriate, in accordance with the procedure Recruitment & Selection (HRS PR0004): • alcohol and drug; • auditory; and • visual; The testing services are provided by external medical practitioners and a summary of the test results is kept by Human Resources Services in accordance with the guidelines specified in the procedure Personal Information & Privacy (HRS PR0006)[130] to maintain confidentiality of
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personnel records for employees. However, if requested, these test results may be disclosed to the candidate. Records of participation in rehabilitation and employee assistance are also retained in files kept by Human Resources Services. 3.7.2.2 Corporate Orientation & Onboarding New ATCO Gas Australia employees are invited to attend Corporate Orientation which is aimed at ensuring the new employees are aligned to the company core values. During the program employees become familiar with the Company, learn about the business and strategic goals and are introduced to a range of key people, policies and processes. Additionally employees will be provided with a site induction relevant to their workplace location. This responsibility sits with the immediate Supervisor/Manager. 3.7.2.3 Induction ATCO Gas Australia field personnel working on the ATCO Gas Australia Network are inducted prior to commencing work on the assets. The objective of this induction is to communicate the safety and health methodologies to be employed to assist in the identification of hazards and mitigation of risks.
3.7.3 Training & Competencies ATCO Gas Australia personnel involved with undertaking maintenance activities on the GDS are provided with a training and development plan tailored to their job and taking into account their education, skills, knowledge and experience levels. New employees are typically supervised by experienced and competent employees until they themselves are deemed competent to perform the required work without direct supervision. The Training Section undertakes workplace assessments in accordance with the Training Management Process (TRN PR0001)[131] specific to the ATCO Gas Australia GDS and in line with relevant procedures and work instructions. The information related to employees’ training and development is maintained by the Training Department. 3.7.3.1 Mandatory Training (Field Personnel) The following internal training activities are mandated for relevant employees: • Site Safety and Environment; • Legislation; • Tooling and Equipment; • Attending Gas Escapes. Such training activities provide relevant employees with an overview of: • a description of the ATCO Gas Australia gas infrastructure; • a list and description of hazards and risks associated with the ATCO Gas Australia GDS; • ATCO Gas Australia policies; • key legislation which ATCO Gas Australia are required to operate under, including the Safety Case regime; • an overview of roles and responsibilities of relevant personnel;
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• hazard identification and risk management techniques; • the Hierarchy of Controls; • the incident reporting framework and associated procedure(s); • a description of the JRA / Take 5 / SWIs and the PTW System; • Emergency Response information and procedures. Mandatory external training for relevant ATCO Gas Australia employees includes: • Construction Safety Awareness Training (White Card) • Basic Work Site Traffic Management; • Provide Cardiopulmonary Resuscitation; • Provide First Aid ATCO Gas Australia’s Training and Events Management System (TEMS) contains information with regard to training required for relevant work streams.
3.8 Asset Management System ATCO Gas Australia’s approach to asset management is defined in its AMS, which is a set of interrelated and interacting elements whose function is to establish the asset management policy and asset management objectives, along with the processes needed to achieve those objectives. The following key elements affecting network asset lifecycles are considered integral to the safe operation of the ATCO Gas Australia GDS and include: • Asset management planning (section 3.8.1) • Design, construction and commissioning (section 3.8.2), which includes project management and capacity and load management • Operational and maintenance management (sections 3.8.3) • Operating Parameters (section 3.8.4) • Asset decommissioning/asset retirement (section 3.8.4) • Outsourcing (section 3.9) • Management of risk (section 3.5) • Management of change (section 3.13) The AMS is supported by the following key documents: • Asset Management Policy • Network Operating Strategy • Network Planning Strategy • Network Maintenance Strategy • Network Replacement Strategy • Asset Management Plans
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• Asset Class Plans
3.8.1 Asset Management Planning Asset management objectives provide the essential link between the organisational objectives and the Asset Management Plans (AMP) that describe how those objectives are going to be achieved. The asset management objectives transform the required outcomes to be provided by the assets, into the activities described in the AMPs and the Asset Class Plans (ACP). AMPs and ACPs are developed to define the activities to be implemented and the resources that will be applied to meet the asset management objectives. The AMPs provide direction to, and expectations for each of the major distribution networks and the ACPs provide direction to, and expectations for each of the major asset classes.
3.8.2 Design Construction and Commissioning Design, construction and commissioning are conducted in accordance with Project Management Manual (PMM) (PMM MA00001)[132]. This defines gates and processes for each of the critical project phases: • Design • Construction & Commissioning • Monitoring & Controlling and • Closing. 3.8.2.1 Design Design is carried out by Engineering Services personnel, who create the PMP as required by Project Management Manual (PMM MA00001). The description of what the project entails, what the end results should look like, and how the project objectives are to be achieved are described. Following project identification and nomination of the Project Manager/Coordinator, a more detailed feasibility study and economic evaluation and/or tender process may need to be carried out. This involves evaluating the alternative solutions and recommending the preferred option that will satisfy the project requirements. Design activities are undertaken by personnel who have knowledge, experience and training in relevant physical assets or operating systems. From time to time ATCO Gas Australia may also utilise the services of external service providers where there is perceived to be insufficient expertise available within ATCO Gas Australia, e.g. welding, bridge design and pipe boring specialists. In such cases, the design inputs are reviewed based on their impact upon safety. Audits of external service providers are conducted to monitor compliance of materials and components used. Engineering specifications have been developed using ATCO Gas Australia’s Engineering Design Guidelines and technical specifications that provide the design basis for equipment to be designed or purchased and become part of the configuration documentation for an approved design. Relevant design guidelines are specified in Section 6 of Project Management Manual (PMM MA00001). They range in complexity from a comprehensive document for major projects that describes functional and performance requirements, to a simple statement of requirements for low cost, low complexity projects. Where no applicable ATCO Gas Australia design guideline exists, the detailed design is undertaken in accordance with relevant regulations, codes and standards.
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Project design outputs are documented and retained to provide a traceable pathway from which design assumptions, calculations or outputs can be confirmed or reproduced. The provisions of the PMM require the use of check and authorisation signatures and revision controls. Authorised and competent personnel review design output documents before their release. Design of new additions to the ATCO Gas Australia GDS are to comply with the following standards and codes, as relevant:
AS/NZS 1596 The storage and handling o/f LP gas [133]
AS/NZS 2566.1 Buried flexible pipelines – Part 1: Structural design [134]
AS/ NZS 2566.2 Buried flexible pipelines – Part 2: Installation [135]
AS 2885.0 Pipelines – Gas and Liquid Petroleum – Part 0: General Requirements [136]
AS 2885.1 Pipelines – Gas and Liquid Petroleum Part 1: Design and Construction
AS 2885.2 Pipelines – Gas and Liquid Petroleum – Part 2: Welding [137]
AS 2885.3 Pipelines – Gas and Liquid Petroleum – Part 3: Operation and Maintenance
AS/NZS 2885.5 Pipelines – Gas and Liquid Petroleum – Part 5: Field Pressure Testing [138]
AS/NZS 3000 Electrical installations (known as the Australian/ New Zealand Wiring Rules) [139]
AS 4041 Pressure Piping [140]
AS/NZS 4645.1 Gas distribution networks – Part 1: Network management
AS/NZS 4645.2 Gas distribution networks – Part 2: Steel pipe systems
AS/NZS 4645.3 Gas distribution networks – Part 3: Plastics pipe systems
AS/NZS 4680 Hot-dip galvanized (zinc) coatings on fabricated ferrous articles [141]
AS 4799 Installation of underground utility services and pipelines within railway boundaries [142]
AS/NZS 4853 Electrical hazards on metallic pipelines
AS/NZS Explosives atmospheres Part 10.1: Classification of areas-Explosive gas 60079.10.1 atmospheres
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Components and materials for the Mains and Services are to comply with the following standards, as relevant:
API 5L Specification For Line Pipe [143]
AS 2885.1 Pipelines – Gas and Liquid Petroleum Part 1: Design and Construction
AS/NZS 4129 Fittings for polyethylene (PE) pipes for pressure applications [144]
AS/NZS 4130 Polyethylene (PE) pipes for pressure applications
AS/NZS 4131 Polyethylene (PE) compounds for pressure pipes and fittings [145]
3.8.2.2 Capacity, Pressure and Load Management Capacity management is the process used to ensure the network capacity is capable of meeting current and future network demands in a proactive and cost effective manner. Capacity management identifies opportunities for improvement and areas of risk and also helps in planning such requirements more efficiently and accurately. It can help in finding scalable solutions to various capacity bottlenecks in the network.
Functions of capacity management are: • Ensuring required service levels are met in all disciplines. • Analysing, Monitoring, and Mitigating the risks with respect to resource utilization • Understanding the current infrastructure performance and analyse the future requirements. • With input from other teams, project the infrastructure required to deliver the business plan. • Managing the requirements for network resources. Benefits of capacity management are: • Improvement of performance of infrastructure components. • Improving the efficiency of capacity. • Elimination of redundant work and ensuring consistent monitoring of infrastructure components. • Improvement of lifecycle costs per service unit components. The document Network Planning Design Standard (AST PL00016)[146], describes the planning strategies to align to AS4645.1:2008 Network Management for: • Network design, taking into account forecasts for changes in gas demand (including climate factors). • Capacity management of the gas distribution network, • Pressure management within the gas distribution network and , • Setting security-of-supply parameters,
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Pressure management is the process used to ensure the gas network is operating within its prescribed operating limits by meeting the minimum pressures of the gas regulating equipment for operability and not over pressuring the gas network. Meeting the minimum pressure requirement is achieved by hydraulic modelling of the gas network and verified against pressure data collected by the Pressure Monitoring Device (PMD) system. The Pressure Monitoring Device (PMD) system consists of individual monitoring units installed strategically throughout the distribution system to observe the distribution system pressures and alarm at a pre-set pressure level. The alarm level is individually selected for each network pressure system. A low pressure alarm maybe an indication that the network is reaching capacity and require reinforcement. This is to ensure the distribution system is capable of providing a secure and reliable means of distributing gas to consumers. This provides the lead time to plan for reinforcement which is identified during system modelling of the network. This timely reinforcement ensures the integrity of the network and mitigates pressure problems before consumers are affected. The high range alarm is a safety level indicating the system has not been over pressurised and thereby a subjecting customer regulator to high inlet pressure. The PMD system also assists Operations in assessing the integrity of the lower pressure distribution system during a major outage on the high- pressure network. ATCO Gas Australia utilizes High Pressure Regulators (HPR) systems pressure monitoring devices to monitor inlet and outlet pressures. This provides operational information on the performance of the regulator sets and the status and integrity of the distribution system. The inlet pressures are used for validating the HP models. Over-pressure shut off devices are installed on the HPR system to protect the downstream gas network from over pressure. Many of the HPR systems have the capability to alarm on OPSO sites. The alarm is one of the methods used to confirm the availability of a regulator during a low pressure condition. Load management, suspension or restriction of supply of gas as necessary due to incident, emergency, potential danger, or other unavoidable incident, that may require interruption, or curtailment, is discussed in Section 3.15.9.
3.8.2.3 Construction and Commissioning Construction and commissioning involves the implementation of the project management activities and supports the provision of the project’s deliverables in accordance with the project plans. This process integrates people and other resources to carry out the activities described in the PMP. ATCO Gas Australia will notify the DES of proposed “major activities” as defined by the GSSS Regulations. ATCO Gas Australia assesses contractors that intend to carry out contracted projects including review of the contractor’s experience and safe work practices, as well as their ability to carry out the project based on available resources. Construction and installation of gas infrastructure such as Mains and Services are to comply with the following standards (as in force at the time of design and construction or any replacements for them in force at that time), as relevant:
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AS 2885.1 Pipelines – Gas and Liquid Petroleum Part 1: Design and Construction
AS 2885.2 Pipelines – Gas and Liquid Petroleum – Part 2: Welding
AS 2885.3 Pipelines – Gas and Liquid Petroleum – Part 3: Operation and Maintenance
AS/NZS 2885.5 Pipelines – Gas and Liquid Petroleum – Part 5: Field Pressure Testing
AS/NZS 4645.2 Gas distribution networks – Part 2: Steel pipe systems
AS/NZS 4645.3 Gas distribution networks – Part 3: Plastics pipe systems
In addition, construction and installation of gas infrastructure must also comply with relevant work procedures specified in Section 3.6. Commissioning of assets is conducted under the relevant Operational process defined in Section 3.6 where SWIs are available for normal operations and a Major Work Permit is used for commissioning outside the scope of existing procedures. Project controls are in place to monitor, measure and control project performance against the project plan. Physical inspections are conducted during construction in accordance with requirements of the PMP. Typically, these inspections include checking for compliance of work standards and materials with ATCO Gas Australia’s Inspection and Test Plan (ITP) relevant to the work. Following construction of the gas infrastructure or implementation of a designed system, a process of validating that the design conforms to defined requirements is undertaken. This is used to confirm that design, construction and quality requirements of the project have been met, and to capture any lessons learnt and opportunities for improvement on future projects. Typical validation activities may include: • hydrostatic or pneumatic testing of constructed works • non-destructive testing of components • type testing of components • calibration of measuring equipment or instruments used in pressure testing • inspection of installations or workplaces • monitoring of operating parameters • auditing of methods and processes • obtaining third party certification of materials, components and systems • issuing of a Manufacturers Data Report • reviewing & signing off ‘as-built’ drawings • testing in-service leaks
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• DCVG to identify defects in coating For works conducted outside the scope of a project that have a specified SWI, ATCO Gas Australia contractors are inspected based on varying frequencies depending on the work that is being conducted as defined in Work Site and General Inspection (TCO PR0001)[147]. The findings from the monitoring and inspections are reviewed to enable: • any required Corrective Actions (CAs) and rectification notices to be issued • any required improvements to be implemented CAs are monitored for completion and implementation of related recommendations are monitored and assessed for effectiveness.
3.8.3 Operations and Maintenance Management GDS operations and maintenance management is conducted in accordance with the relevant operational procedures, refer to section 3.5.1 and the following asset management documents and relevant standards: • Network Operating Strategy (AST ST00004) • Network Maintenance Strategy (AST ST00002) • Asset Class Plan – Pipelines, Mains and Services (AST PL00009) • Asset Class Plan – Pressure Regulation Facilities (AST PL00012) • Asset Class Plan – Metering Facilities (AST PL00010) • Asset Class Plan – Telemetry Equipment (AST PL00013) • Asset Class Plan – Cathodic Protection Systems (AST PL00006) • Asset Management Plan – Albany Network (AST PL00004) [148] • AS 2885.3:2001, Pipelines – Gas and Liquid Petroleum – Part 3: Operation and Maintenance • AS/NZS 4645.2:2008, Gas distribution networks – Part 2: Steel pipe systems • AS/NZS 4645.3:2008, Gas distribution networks – Part 3: Plastics pipe systems The ACPs outline the asset lifecycle strategies adopted for each major asset class. The ACPs utilise, as part of an overall optimised asset lifecycle, the management strategy for the ATCO Gas Australia GDS. The approach to maintenance detailed in these plans is based upon a balance between risk management, Reliability Centred Maintenance (RCM) principles and previous maintenance practices based on past operational experience. An objective of the ACPs is to provide a pro-active maintenance strategy (rather than reactive), which is intended to optimise asset life cycle costs, and maintain security of supply and safe, efficient and reliable operation of the ATCO Gas Australia GDS. Where regulations or standards specify a maximum interval for preventive maintenance to manage risks to or from the GDS, those intervals are reflected as the maximum interval and specified within the relevant ACP. In addition, the maintenance program is based on RCM analysis using the Isograph Ltd Availability Workbench Software. A key purpose of this analysis is to establish an optimal preventive maintenance program for assets to minimise costs without compromising risk reduction measures, and to identify assets that may require re-design.
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The outcomes of the RCM analysis are used to support any proposed review of the maintenance intervals and the required maintenance activities. If required, key maintenance activities and associated performance indicators and targets are reviewed against the qualitative risk assessment matrix. Together with the prescribed codes and regulations, this risk assessment forms the basis for determining the ATCO Gas Australia preventive maintenance program. Maintenance intervals and tasks prescribed in the ACPs are translated into maintenance plans and maintenance items in ERP. Each item: • Contains a list of operations requiring action (with regards to maintainable items). • Produces work orders for an asset or group of assets for regular preventive maintenance and scheduled inspections. • Records maintenance information on each work order at completion of the work. Information includes details of maintenance conducted. • Provides a mechanism for generating corrective maintenance work orders for equipment faults. These include equipment failures and faults that occur prior to scheduled maintenance. • Provides data for analysis and improvement of the performance of the assets. ERP Maintenance Plans are created based on designated maintenance intervals for particular assets and work orders are automatically issued according to the assigned schedule. The implementation of the preventive maintenance plan, as well as asset performance and fault histories, are recorded in ERP and assessed annually. ACPs are reviewed annually to assess maintenance activities carried out, and to assess the ongoing appropriateness of the maintenance regime and KPI targets. This report is documented in Assets & Systems Performance & Health Monitoring (AST PR0005). Key maintenance activities described in ACPs include: • Pipeline Patrol • MAOP and Condition Assessment Review • Cathodic Protection Review • Inspection of Above Ground Pipe Work • Earthing Reviews • Review of Foreign Structure Crossings • Maintenance of Regulators Sets • Pipeline Isolation Valves Maintenance • PRS Condition Monitoring
3.8.4 Operating Parameters The GDS operating parameters are defined in the reference documents listed in Section 3.8.3 which includes details on the following: • normal operating pressures; • regulator set capacities;
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• gate station capacities; • LPG Storage Facility capacities; • operating configurations; and • gas quality requirements. Network Operating Strategy (AST ST00004) is reviewed and updated annually by the Manager Asset Services. It is intended to be sufficiently detailed to allow for the assessment of risk resulting from loss of supply or overpressure, i.e. by defining minimum (based on historical anecdotal evidence and pressure control equipment specifications) and maximum (AS 4645, and AS 2885 requirements for MAOP) allowable operating pressures for the ATCO Gas Australia GDS.
3.8.5 Asset Decommissioning/Retirement Decommissioning of ATCO Gas Australia GDS assets is conducted in accordance with Decommissioning Mains and Commercial Services (SWI MA 003)[149]; or under an asset specific PMP, or decommissioning plan, for assets with MAOP’s of 500kPa or greater. Decommissioning involves purging the pipework of flammable/hazardous contents and leaving the pipework filled with clean air. Where economical, the components of decommissioned assets are salvaged, refurbished and tested to determine their suitability for re-use. Where assets cannot be salvaged economically they are made safe, until disposed of appropriately. Where decommissioned assets are not removed, information on their location and status is recorded in GNIS. Records are updated in ERP, and decommissioned assets are removed from the maintenance schedule where required. Asset Retirement (ENS GL0009) [151] outlines the management process to be followed after ATCO Gas Australia GDS facilities, Pipelines, Mains and Services have been decommissioned. For pipelines with operating pressures greater than 1050kPa, consideration shall be given to the preparation of a pipeline specific abandonment plan in accordance with AS 2885.3. Once decommissioned and made safe, the options available to effect the retirement of the pipework are outlined in Asset Retirement (ENS GL0009) as follows: • removal • abandonment in-place • reuse / transfer of ownership Records are kept in GNIS by Engineering Services for abandoned pipelines, identifying and locating sections of the abandoned asset, to prevent mistakes in identifying an abandoned pipeline as an operational pipeline.
3.9 Outsourcing ATCO Gas Australia engages the services of vendors and service providers for a range of activities via the Procurement Policy (COM PO00001) [152].
3.9.1 Vendors Vendors provide equipment and materials to ATCO Gas Australia, and these goods are procured via Purchase Order.
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3.9.1.1 Supply Chain, Procurement and Quality Control The supply chain and procurement processes utilised for purchasing of equipment and materials require suppliers to produce acceptable evidence of material conformity, e.g. material certificates, according to contract requirements. Suppliers are selected based on their quality standards and their ability to meet specifications, and where applicable, contractual requirements. 3.9.1.2 Materials and Equipment ATCO Gas Australia has a material management system as per Materials Management Process (ENS PR0029). This procedure describes the approval process of tools and materials used by ATCO Gas Australia including the approval, supply, traceability and use of critical materials and components. There is a register of approved materials and tools used by ATCO Gas Australia stored on DMS. This register records the relevant approval information such as standards, testing, management approval and relevant technical specification. Materials and equipment in current use are manufactured in accordance with Technical Specifications maintained in DMS, within the folder ‘Control Documents Technical Specifications’ which describe specifications, quality control, handling and installation.
3.9.2 Service Providers ATCO Gas Australia engages Service Providers to provide some services in relation to Prescribed Activities on the ATCO Gas Australia GDS. Service Providers are engaged via a Contract for minor and major works. Low value/risk and one off purchases may be issued through a Purchase Order (In consultation with Procurement and Legal) by completing the Purchase Requisition Email Template. The procedure Contractor Engagement (COM PR0003) [153] is used when engaging a Service Provider. Service Providers are required to complete the form Contractor Application (Type A) (COM PR0003 RF02) [154] and provide the relevant documentation relating to their safety management systems for assessment prior to engagement. ATCO Gas Australia maintains a register of Service Providers that includes their performance history. The relevant manager reviews the performance of Service Providers, including their safety performance, and completes the form Periodic Contractor Evaluation (COM PR0003 RF07) [155]. Records are maintained within EIM. ATCO Gas Australia implemented a new field services contracting model in 2016. The contract was designed to attract customer focussed contractor companies that can support ATCO Gas Australia in the delivery of its strategic objectives of operational excellence and efficiency, whilst having capacity and industry knowledge to contribute to growth initiatives. The contract model is designed to deliver optimum cost versus risk outcomes and continuously improve HSE and work quality performance, whilst fostering a culture of shared innovation. 3.9.2.1 Service Provider Contract evaluation process ATCO Gas Australia utilises the services of contractors who carry out construction or repair activities on the ATCO Gas Australia GDS. The services of consultants are also utilised to undertake some activities in relation to Prescribed Activities on the ATCO Gas Australia GDS. Contractor and support services are procured in accordance with Procurement Policy (COM PR0001) by either quotation or tender depending on the Contract value. The contract bid, evaluation and selection process promotes the importance of safe work practice and a safe working environment for contracted work. This process ensures that ATCO
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Gas Australia obtains the most competitive offer and qualifications from a range of suppliers for the safe provision of works or services. The ATCO Gas Australia evaluation team have duties to act ethically and honestly in all aspects of their roles in accordance with the Probity Guidelines (COM PO00001 GL0002) [156]. All evaluation team members are required to sign the Probity Checklist (COM PO00001 GL0002 RF01) [157] prior to commencing evaluations. When ATCO Gas Australia does not go to tender, the method of obtaining the quotes or awarding the contract must still comply with the remainder of Procurement Policy (COM PO00001). Internal approvals are sought in order to commit funds, and Managers are required to provide input to give the approval. This may require preparation of a Business Case in compliance with ATCO Gas Australia Network Infrastructure Business Case (FIN PR0003) [158] or a capital expenditure approval request in compliance with ATCO Gas Australia Capital Expenditure Appropriation Request (FIN PR0004) [159]. A Contract Approval Form (COM RF10) is required for all Contract engagements. The Contract Approval Form is to be approved by all relevant signatories as per the Contract Approval Guidelines (AA-GOV-GL-001). In all Contract engagements the minimum approvals required is Governance/Compliance, Legal and Finance. Legal and Procurement are to be engaged at the planning phases of all Contractor engagements. The contract with such consultants and contractors will specify objectives and performance requirements, including those for safety performance. The requirements to comply with relevant standards, codes and legislation, and to develop and implement procedures are incorporated, as required, into contractual agreements. Contractors will be monitored against KPI’s throughout the term of their Contract.
3.9.2.1 Service Provider Safety Requirements ATCO Gas Australia considers the ability of service providers to work safely as a key factor in the selection process. Assessment of contractors includes consideration of their experience, ability to perform the work adequately, and provision of a Safety Management Plan that is consistent with policies implemented for the ATCO Gas Australia GDS provided to ATCO Gas Australia within the contract documentation. In the case that a contractor is required to use ATCO Gas Australia procedures and Safety Systems, they are provided with the relevant procedures, and trained and assessed as competent in those procedures and Safety Systems prior to work commencing, and records of this are maintained in EIM. As part of the tender process, references of prior similar works are to be submitted. Referees will be contacted as part of the due diligence process prior to engagement. When contractors are engaged, the scope of obligations imposed by ATCO Gas Australia will depend on the scope of their work and the risks involved. Contractors are advised of these requirements prior to the commencement of a contract and within the contract documentation. Dependent upon the scope of work to be undertaken, contractors may be required to submit information or procedures pertaining to: • audit of safety and health including past performance; • induction and training; • inspection of equipment; • pre-qualification; • requirement to report hazards/incidents;
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• rating of Contractor safety performance; • Safety Management Plan or Safety Program; and • HSE Policies. Where it is determined that the contractor is required to submit a Safety Management Plan, the following areas are to be encompassed, as appropriate: • contractor’s safety and health policy; • organisation/management structure; • hazard/incident reporting procedure; • safety meeting schedule; • workplace environment; • schedule of workplace inspections; • equipment certification, inspection and testing; • site security; • a system to ensure subcontractor safety; • training /induction; • work procedures; • JRA / Take 5 / Safe Work Method Statements / Safe Work Instructions; • Personal Protective Equipment; • traffic/transport management; • audit system; and • Emergency Preparedness. In accordance with the PMP, ATCO Gas Australia inspects contracted work against contract specifications, or the specific contract PMP throughout the duration of a project as detailed in the Inspection and Test Plan (ITP) for each project. The level of detail in the ITP and frequency of inspections is dependent on the scope of project works, and guidance is available in the procedure Inspection and Test Plan (ENS PR00001 RF02) [160].
3.10 Gas Network Information System (GNIS) ATCO Gas Australia operates a geographically based mapping system, Gas Network Information System (GNIS), which identifies the physical location of ATCO Gas Australia GDS assets. This includes pipes conveying gas, PRSs, isolating valves, Regulator Sets, Meter Sets, meters and pipe protection systems. The GNIS interfaces to ATCO Gas Australia’s ERP, the National Dial-Before-You-Dig (DBYD) service, Network Data Visualisation (NDV) used to track vehicles and monitor work, and DMS. On 26 May 2014, ATCO Gas Australia replaced AssetView, as the network browser to view GNIS, with the Infrastructure Browser Information System (IBIS). The GNIS is a spatial database that is regularly updated from cadastre and address data supplied by Landgate, the Western Australia Land Information Authority. The data is provided in GDA-94 (Geocentric Datum of Australia) Coordinate System [161].
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The GNIS data is also made available to external applicants, such as those undertaking excavation in the vicinity of pipes, via the DBYD service. The GNIS DBYD service is considered to be a key protection measure for prevention of third party damage caused by excavation or boring operations. ATCO Gas Australia also provides GNIS to gas retailers and Main laying contractors. Further detail on this service is provided in Section 3.11.2. Information for ATCO Gas Australia GDS Pipelines is further supplemented by separate computer aided design, which provides additional details on the Pipeline location, elevation drawings, Regulator Sets and industrial / commercial consumers. In addition to the above information systems, a separate set of HP schematics is maintained to provide quick reference during an emergency. The drawings identify the pipe numbers, valves, Regulator Sets with inlet pressures above 350 kPa and customer Meter Sets installed immediately downstream of these Regulator Sets. A copy of the GNIS system is also available on a dedicated computer in the Control Room at the ‘Jandakot depot’. This is intended to facilitate an effective and timely response to emergencies, when the primary computer network is unavailable. Updates are applied to the copy of the GNIS kept on the dedicated computer, under the supervision of the Manager Network Control, every three weeks with the latest GNIS data available.
3.11 Third Party Damage Prevention ATCO Gas Australia recognises that one of the most significant risks to the integrity of the GDS arises from third party activities that may cause damage to the GDS. ATCO Gas Australia has various processes and systems in place for minimising hazards associated with third parties working within the vicinity of ATCO Gas Australia HP Pipelines. ATCO Gas Australia prevents third party damage to high pressure assets by: • promoting clear lines of communication and educating third parties about established procedures for obtaining information and approvals for working around high pressure infrastructure; and • undertaking surveillance of high pressure assets via periodic pipeline patrols. • Executing strategies as per Third Party Pipeline Damage Prevention Manual (NCO MA00001)
3.11.1 Pipeline Marker Signs Pipeline marker signs are employed to identify Pipelines and alert third parties of the presence of the Pipeline. The pipeline marker signs are located at intervals in accordance with AS 2885. Details on these intervals can be found in Section 2.4.8. The pipeline marker signs contains information to advise third parties of the type of Pipeline, the contact number to call in the case of an emergency and the internet address and phone number for the national DBYD service.
3.11.2 Dial Before You Dig DBYD is a national referral service for third parties wanting to know the location of underground networks (including gas pipelines and mains) at proposed civil construction sites (e.g. excavation, augering, horizontal directional drilling, etc. in the road reserve and private property). ATCO Gas Australia participates in the DBYD initiative for the provision of asset location maps to third parties and maintains representation on the Board of “Dial Before You Dig WA,” which increases the effectiveness of this initiative in relation to ATCO Gas Australia GDS assets.
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An automated system, Automated Information Referral System (AIRS), provides automated detailed responses to requests for maps from third parties via the DBYD service as defined by Dial Before You Dig System (CCT WI002)[162] . The responses contain requested maps and supporting documentation detailing requirements for further contact with ATCO Gas Australia if certain risk criteria are met, such as working within 15m of a high pressure Pipeline. The supporting documentation includes requirements for third parties to obtain notifications and approvals from ATCO Gas Australia when working within the vicinity of HP assets and stipulates circumstances where there may be further requirements for engineering assessments and the need for an ATCO Gas Australia approved HP Pipeline Locator to be in attendance.
3.11.3 HP Pipeline Location and Engineering Assessment Third parties proposing to undertake works within 15m of a high pressure Pipeline are required to notify ATCO Gas Australia for an engineering assessment of the proposed works to confirm that adequate controls and risk reduction strategies will be in place to minimise the impact of proposed work in the vicinity of HP Pipelines, thus reducing the probability of damage to ATCO Gas Australia assets and danger to persons arising from any damage. This notification process is described in Notification of All Works around High Pressure Gas Pipelines (NCN WI008)[163]. For proposed works undertaken within 5m of a HP Pipeline, or in certain cases at distances greater than 5m, ATCO Gas Australia may require that the works are supervised by a HP Pipeline Locator approved by ATCO Gas Australia to ensure that the HP Pipeline is located correctly and that any conditions or controls imposed on the works by ATCO Gas Australia are being met. HP Pipeline Location services are available through approved contractors, or in some instances ATCO Gas Australia personnel depending on availability and demand. ATCO Gas Australia has a process for training, assessing and approving HP Locators. Records of approval are maintained by ATCO Gas Australia’s HP Co-ordinator. Further information regarding HP Location activities and responsibilities are provided in High Pressure Mains Location (SWI ST 006) [164]. Locators are approved in accordance to the document Approved Locator Process (NCO PR0008) [165]. Where engineering assessment concludes that ATCO Gas Australia assets require relocation to allow for proposed works, further consultation with the third party will be sought, and ATCO Gas Australia will take action to ensure that the integrity of the asset is not compromised, in line with relevant legislation. Third parties are made aware of such requirements via various means including: • Supporting information provided via the DBYD service; • Information package, Additional Information for Working around Gas Infrastructure (NCN WI008 RF01) [166], made available to third parties upon request or via ATCO Gas Australia’s public website; and • Education and awareness initiatives (refer to section 3.11.5).
3.11.4 Pipeline Patrol Pipeline patrols are conducted along ATCO Gas Australia HP assets and Critical MP assets at various intervals which are stipulated based on risks posed to the Pipeline, in accordance with Asset Class Plan Pipelines Mains and Services (AST PL00009). Pipeline patrols are undertaken in accordance with Pipeline Patrol (SWI ST 001) [167] in order to: • Monitor third party activity being undertaken within 15m of an ATCO Gas Australia HP asset;
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• Maintain permanent physical access to the ATCO Gas Australia GDS; • Monitor changes to the natural site environment which may impact the integrity of the pipeline (such as loss of depth of cover) and changes to land use; • Maintain legibility and condition of pipeline marker signs; and • If present, detect a smell of gas. Patrols are mostly undertaken via vehicle, however in areas which are inaccessible by vehicle patrols may be undertaken via foot, aerially, or aided with binoculars. In the event that a Patroller discovers unauthorised works being undertaken within 15m of a HP Pipeline, the Patroller may take action to ensure that any risks to the pipeline are minimised, including: • Informing the third party of the presence of the HP Pipeline and instructing not to proceed until ATCO Gas Australia have authorised their works and current gas plans are on-site, in line with the Energy Operators (Powers) Act 1979 [168]. • Recording details including contact names and machinery registrations on High Pressure On-Site Incident Report (SWI ST001 RF01) [169] prior to leaving site. HP On-Site Incident Reports are provided to the ATCO Gas Australia HP Co-ordinator, who may escalate the incident to ATCO Gas Australia Supervisors and/or Engineering Services to ensure action is taken accordingly where there may be a risk posed to an ATCO Gas Australia asset.
3.11.5 Awareness, Advertising and Training ATCO Gas Australia utilises a variety of mechanisms for increasing awareness of hazards and the need for safety precautions to be in place when working near ATCO Gas Australia assets as defined in the Third Party Pipeline Damage Prevention Manual (NCO MA00001) [170]. These include: • Participation by ATCO Gas Australia personnel in external committees such as Utility Providers and Services Committee and various Standards Australia committees; • Conducting Third Party Damage Prevention Awareness Sessions; • Visits by Patrollers and HP Co-ordinator to tool box meetings, project sites and daily meetings; and • Membership of the Energy Networks Association and Australian Pipelines and Gas Association (APGA) • Media communications informing the general public of the dangers of Gas and what to do if a leak is suspected. This can include, Radio, Newspaper and internet communications. ATCO Gas Australia also target companies for repeat offences and offer them advice on the prevention of third party damage to the ATCO Gas Australia GDS.
3.11.6 Land Owners / Occupier Liaison ATCO Gas Australia liaises on an ongoing basis with landowners / occupiers of properties that are traversed by high pressure pipelines within the GDS in accordance with Landowner / Occupier Liaison Procedure (TCO PR0009) [171]. Landowner / Occupier Liaison Procedure (TCO PR0009) outlines how ATCO Gas Australia implement, maintain, review and retain records of the Landowner Liaison process which has been established to prevent external interference to
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high pressure pipelines from third parties who own / occupy land which are traversed by high pressure pipelines. The intent of the landowner liaison process is to ensure that landowners / occupiers are informed of the methods of recognising threats to the pipeline and an emergency situation, and are provided with: • 24 hour contact telephone number to notify in the case of emergency • Information with regard to dangers of interference with the pipeline and its appurtenances • Information to ensure their activities do not endanger the pipeline and its appurtenances and constraints set out on land adjacent to the pipeline.
3.12 ATCO Gas Australia Interaction with Third Parties
3.12.1 Public Road Infrastructure Any works in relation to the GDS that affect any roads are to be conducted in accordance with the relevant legal requirements. Any works will be managed in accordance with the following Safe Work Instructions: • Location of Underground Assets (SWI SSU 002) [172]; • Excavation and Backfilling Requirements (SWI EX 001) [173]; • Traffic Management (SWI SSU 003) [174]; • Barricading (SWI SSU 004) [175]; and • Working in the Vicinity of Overhead Powerlines (SWI SSU 005) [176]. 3.12.1.1 High Voltage Electricity Lines Any works in relation to the GDS in the vicinity of high voltage overhead transmission lines are to be conducted in accordance with the relevant requirements of Working in the Vicinity of Overhead Powerlines (SWI SSU 005) including minimum working clearances and other risk control and mitigation measures. 3.12.1.2 Adjacent Electricity, Telecommunications, Water and Sewage Assets If works are scheduled to be carried out in relation the GDS, then before conducting those works, ATCO Gas Australia personnel are to locate and positively identify any infrastructure in the vicinity that could be affected by those works (e.g. utilising Location of Underground Assets (SWI SSU 002), Excavation and Backfilling Requirements (SWI EX 001) and the DBYD service for any below ground infrastructure and visual inspection for any above ground infrastructure). ATCO Gas Australia personnel are to treat these existing assets as “foreign structure” as defined in the Asset Class Plan – Pipelines, Mains and Services (AST PL00009), including where they are required to be crossed.
3.13 Management of Change The purpose of the Management of Change (MoC) system is to define processes of review, approval and implementation of ATCO Gas Australia gas distribution Network changes that have the potential to introduce hazards, or increase the level of risk to health, safety, environment, property, or the public to control risk to an acceptable level. Management of Change (TCO PR0002)[177] describes the MoC process and includes:
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• changes to plant, tools, equipment, systems or design of the GDS are controlled, fully documented and compliant with the relevant codes, standards and statutory requirements; • proposed improvements or changes to the GDS are technically sound and commercially viable; • improvements or changes to the GDS are assessed and approved by competent personnel; • hazards associated with the change are identified and managed to reduce risks to the public, ATCO Gas Australia employees, contractors and the environment to ALARP; and • documentation, including drawings and procedures, affected by the change is updated to reflect the implemented change. Management of Change (TCO PR0002) describes the process for managing four distinct types of changes which are: • Project Management Changes • Network Pressure Changes(NCO PR0013)[260] • Document Changes • Technical Changes
3.14 Document Control Documentation Control Procedure (QLT PR0001) details requirements for controlling and publishing documentation relating to strategies, policies, procedures and systems for the operation of gas assets and is integral to ATCO Gas Australia’s document management system. Documents are accessible to field personnel through computers at ATCO Gas Australia depots. Additionally, ATCO Gas Australia field personnel have access to the appropriate controlled documentation through their field mobility devices (FMDs).
3.14.1 Revision Management Document Control requires identification of a particular document by a unique number. Each procedure and work instruction document has a process owner, revision number and description (including details of major changes if any were made), and an approvals block. A document review task is assigned to the process owner by the Document Controller. Electronic copies of revised documents are loaded (replacing superseded versions if applicable) onto DMS. Document reviews, including technical reviews, are conducted in accordance with Document Control Procedure (QLT PR0001). Where implementation of the Management of Change (TCO PR0002) procedure results in document modifications, these modifications are controlled using Documentation Control Procedure (QLT PR0001). Revision of controlled documents relating to the SMS is managed using the Document Control procedure, which drives review and approval via relevant personnel. Revisions to SWIs are defined as “MINOR” or “MAJOR” in consultation with various parties, in particular the Document Owner and Training Department and are managed as defined in the following documents: • SWI Review and Sign Off Process (QLT PR0007) [178], and • Technical Services Department Document Production Guideline (QLT PR0008) [179].
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3.14.2 Records Management Records and documents that demonstrate the maintenance and implementation of controls identified through the FSA are stored either; electronically on ERP, DMS or in hardcopy format by the relevant department and their access controlled. Records retention requirements are described in Records Management Procedure (AA-GOV-PRO-001). There is currently no specified retention time for data stored on DMS. Hard copy records have their retention times specified upon archive. A register of archived documents creates a receipt of archived documents and keeps track of required retention times for hard copy records including the date for disposal of records. This archive register includes a record of destroyed archived items to date. Records which aid in the effectiveness of emergency response such as the location of isolation valves and regulators are readily available and kept up to date through the drawing management system GNIS described in Section 3.10. GNIS provides a maintained and up-to-date record which shows the location of buried assets including changes to assets and decommissioned assets. Documents listed in the Controlled Document Register are reviewed on a routine schedule (or more frequently as deemed necessary, for example due to changes in legislation) in line with the requirements of Document Control Procedure (QLT PR0001).
3.15 Incident and Emergency Management ATCO Gas Australia acknowledges that although reasonably practicable efforts are made to protect people from hazards and to prevent accidents, there remains a potential for these to occur due to the nature of gas distribution activities. In an effort to address this residual risk, ATCO Gas Australia maintains an emergency and repair capability including emergency response systems, specialised equipment and competent and trained personnel to react to foreseeable hazardous events associated with the ATCO Gas Australia GDS. The President has overall responsibility for the management of emergencies on the AGA GDS. Emergency management is undertaken by personnel from the Operations, Construction, Asset and Engineering Innovation and HSE departments in accordance with roles and responsibilities defined within the ATCO Gas Australia Emergency Response Management Plan (TCO PL00001) (the ERMP). Emergency management planning is undertaken by the Technical Compliance team in consultation with these four ATCO Gas Australia departments.
3.15.1 ATCO Gas Australia Emergency Response Management Plan ATCO Gas Australia has developed and maintains an emergency management process, documented in the ATCO Gas Australia Emergency Response Management Plan (TCO PL00001) (the ERMP), to protect life and property, and assist in maintaining a safe and reliable gas supply to consumers during an emergency. Emergency management processes have been developed based on outcomes of various safety studies, relevant regulatory requirements (detailed in Section 1.3 of the ERMP) and in consideration of the recommendations from emergency service providers. The ERMP provides a description of the key elements of ATCO Gas Australia’s emergency management processes, including: • The position that has continuous responsibility for implementation of the ERMP. • Specific Personnel responsibilities, for example the position responsible for:
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o reviewing and revising the ERMP; and o coordinating the conducting of emergency exercises • Training group provides an overview of training required for personnel who may have direct involvement in the response to and management of emergencies. • During and after hours emergency response roles, for example the rostered Duty Officer, Supervisor and Manager roles. • Incident Classification and Escalation – Provides guidance for the classification of incidents:
o Level 1 (Minor Incidents), o Level 2 (Major Incident), and o Level 3 (Emergency) to o Level 4 (Crisis). o The triggers and thresholds that escalate incidents to higher levels. This escalation is in response to the size and/ or complexity of the incident. • Incident and Emergency Management Structure – Provides a link to key emergency response personnel contact details, provided in Emergency Contacts Phonebook (TCO PL00001 RF02) [180]. This section also provides an overview of incident, emergency, crisis and business continuity management structure. • Incident and Emergency Response – Provides guidance for the implementation of emergency processes and details the following:
o Types of emergencies and supporting plans or procedures (including Depot Emergencies which is documented in Depot Emergency Evacuation Procedure (HSE PR0023)[181]
o Pre-Incident Plans covering reasonably foreseeable scenarios that could occur on the GDS to provide guidance to the Emergency Commander in the event of an emergency (Pre-Incident Plans (TCO PL00001 RF16)[182]). The plans provide guidance on potential hazards, exposures, remediation activities, reference documents, post-incident activities, and internal and external notifications.
o Initial incident assessment and classification o Injury management processes and procedures o Internal and external notifications and notifiable incidents o Emergency Management Team (EMT) and on-site Incident Management Team (IMT) formation and the roles and responsibilities within these teams
o Environmental management, sensitive areas and management plans o Legal issues o Communications (refer to Section 3.15.5) • ATCO Gas Australia Incident Command Centre – Details of the ATCO Gas Australia Incident Command Centre and back up locations if the primary Incident Command Centre is not available (refer to Section 3.15.6)
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• Emergency Exercises – Provides an overview of ATCO Gas Australia’s emergency exercise program (refer to Section 3.15.7).
3.15.2 GDS Isolation In the event of an incident or emergency on the GDS, GDS isolation is performed in accordance with Network Isolation (NCO PR0016)[183], utilising GNIS, pipeline schematics, specific pipeline or GDS isolation plans, procedures and instructions (refer also to sections 3.15.3 and 3.15.4).
3.15.3 Pipeline Schematics The following pipeline schematics are available to assist with determining GDS isolation • Pipeline Schematic; PL Schematic – P4-900-0332-01 – Metro Southern Region [184] • Pipeline Schematic; PL Schematic – P4-900-0332-02 – Fremantle Region [185] • Pipeline Schematic; PL Schematic – P4-900-0332-03 – Rockingham Region [186] • Pipeline Schematic; PL Schematic – P4-900-0332-04 – Bunbury Region [187] • Pipeline Schematic; PL Schematic – P4-900-0332-05 – Metro Northern Region [188] • Pipeline Schematic; PL Schematic – P4-900-0332-06 – Geraldton Region [189]
3.15.3.1 Isolation of Steel Pipelines with a MAOP of 700kPa or greater For steel Pipelines built in accordance with AS 2885, equipment shall be provided within that Pipeline for the isolation of segments of the Pipeline, depressurisation and bypass capability and an isolation plan shall be documented. Isolation of these segments may be required for planned maintenance, changes to the Pipeline, or an event (incident) that causes a LOC within a Pipeline segment, or there is a significant risk of a LOC. Individual Pipeline Isolation Plans for steel pipelines subject to the requirements of AS 2885 (but not subject to the requirements of AS 4645, Appendix A), currently include: • WAGN Geraldton Lateral – HP102 Isolation Plan for WAGN (82802-DOC-002)[190]; • HP 125 Pipeline Isolation Plan (TCO PL00014)[191] for the Karrinyup Class 150 pipeline; • HP134 Pipeline Isolation Plan (TCO RP 0125)[192] for the Byford pipeline; • HP132 Pipeline Isolation Plan (TCO RP 0124[193] for the Ellenbrook pipeline; • HP131 Pipeline Isolation Plan (TCO RP 0123)[194] for the Aberdare Road Nedlands pipeline; • HP128 Pipeline Isolation Plan (TCO RP 0122)[195] for the Abbey Street Morley pipeline); and • HP127 Pipeline Isolation Plan (TCO RP 0121)[196] for the Fiona Stanley Hospital pipeline. • Mandurah Gas Lateral (HP120 & HP129) Pipeline Isolation Plan (TCO PL00015)[197] for HP129 that is part of the GDS from PRS015 located off Readheads Rd Nambeelup to Mandurah Rd San Remo (Mandurah) For these Isolation Plans, depressurisation and bypass points are identified using Pipeline Schematic drawings available in DMS, or GNIS, or a combination of both. Issues such as whether or not the pipe is looped or back gassed may impact on the ability to isolate a Pipeline
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segment, whilst minimising loss of gas supply to consumers, and such issues are in the Isolation Plan as required. ATCO Gas Australia also has the capability of installing isolation equipment within a steel Pipeline which is installed under a Major Work Permit Form (TCO PR0007 WI004 RF02). Where required, new ATCO Gas Australia GDS Class 150 and over steel pipelines, with MAOP exceeding 1,050 kPa, are designed, in accordance with AS 2885 and Engineering Services Design Guideline Pipelines (ENS PR 0019)[71]. These Pipelines can be isolated at mainline valves, and are designed and selected in accordance with the recommendations of Engineering Services Design Guideline Valves (ENS PR 0018)[200] 3.15.3.2 Isolation of the CBD The segment of the ATCO Gas Australia GDS, which operates in the Perth CBD, contains cathodically protected coated steel pipes from 50mm to 150mm in diameter and currently operates at 160 – 200 kPa. It is configured into zones that allow it to be isolated into four (4) major areas via operation of the isolation valves strategically located as described in CBD Emergency Isolation (TCO PL00001 WI004)[201]. The configuration allows the normal operation of any three (3) zones in the event of an emergency in the fourth. It also allows the complete isolation of a zone or a reduction and continued operation of that zone at lower gas supply pressure. Complete zone isolation involves the operation of one (1) or two (2) valves in Wellington Street and two (2) other valves adjacent to the corresponding pressure regulator set. The process for isolation of the CBD is described further in CBD Emergency Isolation. 3.15.3.3 Isolation of Mains and Services In the event of an incident, or where required for planned maintenance, Mains and Services can be isolated. Mains and Services (SWI RT 001)[202]) provides decision trees for available flow stopping methods utilised by ATCO Gas Australia including: • Operating Rogan Equipment (SWI FS 001)[203] • Rogan Single Bag Isolation (SWI FS 002)[204] • Clements Plugging Tool (SWI FS 003)[205] • Service Riser Plugging Tool (SWI FS 004)[206] • Operate Manual Squeeze-Off – Service Isolation Only (SWI FS 005)[207] • Service Plugging Tool (SWI FS 006)[208] • Operation of a Cutter Tee (SWI FS 007)[209] • Modified Tapping Band Replacement Tool (SWI FS 008)[210] • Operate Squeeze-Off – Monitor and By-pass (SWI FS 009)[211] • Service Valve Replacement Tool (SWI FS 010)[212] • Live Gas Service Isolator Tool (SWI FS 011)[213]
3.15.4 Field Emergency Response Unit (FERU) The FERU consists of employees who are specifically trained to respond to emergencies and are equipped to respond to gas escapes involving high, medium and low pressure gas utilising Self Contained Breathing Apparatus and appropriate specialised PPE. The use of FERU is
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described in Use of FERU (SWI FERU 001)[198] and its referenced documents covers aspects for deployment of the FERU Team including assessments required prior to deployment of field employees. The FERU Team conducts training to maintain emergency preparedness and competency of team members. Training sessions cover responding to simulated leaks and correct use and maintenance of equipment. Careful consideration is given to alternative means of repair prior to dispatching FERU. Use of the FERU may be considered for situations including the following: • timely response to gas escapes; • public safety; • resource and material availability; • minimise potential impact to the ATCO Gas Australia GDS; and • where standard operating procedures are not applicable. The following SWIs describe specialist steel pipe isolation, maintenance, or repair methodologies: • Halt' Shut-Off Device Utilising the FERU (SWI FERU 002)[263]; • Plidco Flange+Repair-Ring Utilising the FERU (SWI FERU 003)[264]; • Plidco Split+Sleeve Utilising the FERU (SWI FERU 005)[265]; • Skinner Vented Plug Clamp Utilising The FERU (SWI FERU 006)[266]; and • Squeeze-Off Steel Pipeline Utilising the FERU (SWI FERU 007)[267].
3.15.5 Emergency Communications HSE event and emergency response management capabilities for the ATCO Gas Australia Network are maintained 24 hours a day, 365 days a year. After hours management and supervisory support is maintained in accordance with After Hours Callout Roster (TCO PL00001 WI003)[214]. ATCO Gas Australia maintains a Faults and Emergencies Telephone Number, 13 13 52 which is manned at all times, and supported through a Call Centre, based at the Jandakot Operations Centre and equipped with an emergency backup power supply. In the event that the Control Room is inoperable or inaccessible, the telephone lines are set up to be diverted to a dedicated area within Level 12 of 2 Mill Street, Perth, where appropriate equipment is available for emergency management purposes. The Call Centre manages the call volume and passes the key information to the Control Room, adjacent to the Incident Command Centre (ICC) which provides a centre for the co-ordination and monitoring of work, and for emergency response, involving the ATCO Gas Australia Network. The Control Room is operated by trained personnel, who have documented procedures and computer and communications equipment intended for the purpose of managing and co- ordinating emergency activities in accordance with the Emergency Procedures. Emergency services agencies such as the Department of Fire and Emergency Services (DFES) and WA Police have a dedicated phone line directly to the Control Room. There is a dedicated employee emergency number for initial communication should an emergency be initiated while ATCO Gas
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Australia personnel are working of the ATCO Gas Australia network. Refer to Emergency & Operational Contacts (TCO PL00001 RF07)[215]. ATCO Gas Australia teams working on the gas infrastructure assets are provided with mobile phones to be used as their principle form of communication in the event of an emergency, however ATCO Gas Australia field vehicles are also provided with two-way hand-held, or trunk radios for direct communication back to the Control Room. Where an incident has been declared an emergency in accordance with the ATCO Gas Australia ERMP and Emergency Management Team (EMT) is assembled, the ERMP provides instruction for the allocation of an EMT Communications Function and an on-site IMT Communications Officer. The person responsible for the EMT Communications Function develops the communications plan, maintains communications with the IMT Communications Officer and, where required, the ATCO Gas Australia leadership team, corporate communications team and external parties i.e. regulatory authorities, emergency service and government agencies. The person responsible for the IMT Communications Function maintains communications within the IMT, to liaise with external parties, which may include the on-site emergency service agencies communications officer, and undertaking regular agreed communications back to the EMT Communications Officer. During an emergency the relevant information is recorded in ERP and forms an emergency log. The ERP emergency log can then be used to review the incident and debrief staff involved in the emergency, and to assist in improving the management of future emergencies.
3.15.6 Incident Command Centre Emergencies occurring on the GDS will be co-ordinated and managed in the ATCO Gas Australia Incident Command Centre (ICC) located at the Jandakot Operations Centre, 81 Prinsep Rd, Jandakot. The ICC is directly adjacent to the Control Room and has been set up with necessary equipment to manage emergencies, including hard copies of emergency documentation, a log keeping computer, white boards, a dedicated phone line and projectors. In the event that the Jandakot ICC is inaccessible, there is provision for a backup incident room within ATCO Gas Australia’s Mill Street office.
3.15.7 Emergency Services Cooperation Western Australia’s peak emergency management body, the State Emergency Management Committee (SEMC), has delegated the responsibility to ensure the development and review of the State Emergency Management Plan for Gas Supply Disruption [Westplan—Gas Supply Disruption][216] to the Coordinator of Energy, Public Utilities Office. This Office, in turn, oversees the Operational Management Group (OMG) - of which ATCO Gas Australia is a member - which is responsible for non-operational strategy relating to gas supply issues in Western Australia. The OEM, in turn, oversees the Essential Services Network Operators Reference Group (ESNORG) - of which ATCO Gas Australia is also a member - that works to ensure cooperation between network operators and for the sharing of resources and emergency equipment when necessary. The aim of the group is to detail how and when assistance may be given between ESNORG members in the event of an emergency occurring which requires their involvement or affects their infrastructure. In the event of normal communications breakdown i.e. mobile and landline phones, a dedicated two-way radio has been provided to members as a secondary means of communication which is
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on a dedicated police frequency. Each month the two way radio system equipment is tested for correct operation. ESNORG Communications (CTR PR0002 WI002), based on the mutual assistance policy and principles of the signatories of ESNORG, sets out communications protocols between the group’s members in the event of an emergency occurring which requires their involvement or affects their operation or infrastructure. This mutual assistance forms part of the ATCO Gas Australia Network Infrastructure emergency procedures. This ensures cooperation between signatories to minimise disruption of supply of gas to WA users.
3.15.8 Testing, Evaluation and Review The Manager Technical Compliance has overall responsibility for reviewing and revising the ATCO Gas Australia ERMP and for conducting emergency exercises. ATCO Gas Australia conducts a minimum of five emergency exercises per annum (pa) on the ATCO Gas Australia Network as part of a six (6) year rolling program. ATCO Gas Australia’s emergency exercise program is described in Emergency Exercises (TCO PL00001 WI002)[217]. These emergency exercises are facilitated by experienced ATCO Gas Australia personnel with the necessary skills, and may be field or desktop exercises. ATCO Gas Australia seeks attendance from representatives from organisations with emergency response responsibilities, including WA Police, DFES and Local and State Emergency Management Advisory Committees, as appropriate. Recommendations for improvements arising from evaluation of the effectiveness of emergency exercises are incorporated into the ATCO Gas Australia ERMP or other emergency response procedures as part of a continuous improvement process, and to maintain emergency response mechanisms as fit for purpose. Emergency response procedures are also reviewed through ongoing assessment of accident/incident reports, audits, and reviews of specific procedures at defined review intervals.
3.15.9 Emergency Gas Supply Load Management During an incident it may be necessary to carry out load management by interruption and/or curtailment to continue to supply gas and to mitigate loss of supply to priority customers. Curtailment will be managed in accordance with Gas Supply System Emergency (OPS PR0001)[218] and Curtailment (MSR PR0004)[219]. It may also be necessary to curtail gas usage on a wide scale, beyond that achievable by curtailing the major consumers. The Minister for Energy will be notified by ATCO Gas Australia of a gas supply system emergency situation and a request for an Emergency Order to be declared in accordance with Gas Supply System Emergency and Curtailment. Action may also be required in accordance with the Westplan—Gas Supply Disruption.
3.16 Leak Management Due to the size, age and complexity of the ATCO Gas Australia GDS, minor gas leaks occur. Managing gas leakage on the ATCO Gas Australia GDS to minimise hazards associated with gas leaks is considered to be an important factor in agreeing ATCO Gas Australia’s asset repair and replacement program each year. ATCO Gas Australia has developed and implemented a Network Maintenance Strategy (AST ST00002) and Network Asset Replacement Strategy (AST ST00001)[220] to establish guidelines for maintaining, repairing and replacing assets based on safety and economic considerations.
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The replacement strategy sets out ATCO Gas Australia’s philosophy in relation to asset replacement in order to reduce network leaks and provide a safe, reliable and economic gas supply to consumers. The intent of this philosophy is to provide consistency in the approach to asset replacement to provide a balanced, efficient and effective replacement of the ATCO Gas Australia GDS assets, in-line with ATCO Gas Australia strategies and covers all major asset categories within the ATCO Gas Australia GDS, such as pipes, regulators and valves. ATCO Gas Australia conducts scheduled leak surveys as detailed in the following Asset Class Plans: Asset Class Plan – Pipelines, Main and Services (AST PL00009); Asset Class Plan – Metering Facilities (AST PL00010); and Asset Class Plan – Pressure Regulating Facilities (AST PL00012). The schedule is currently based on the concept of surveying: the ATCO Gas Australia GDS once every 5 years for suburban locations; High Risk, City Centre Area (CCA), Central Business District (CBD) and Multistorey locations annually; and selected metallic mains every three years based on their relevant near-term replacement strategy. The Leak Survey requirements are completed in accordance with AS 4645 requirements and prescribed within the Leak Survey FSA (TCO RP 0106) and Leak Survey FSA Review (TCO RP 0246).All leaks located during the survey are leak classified and repair work scheduled according to the Leak Classification. Members of the public are able to reports leaks, typically by calling the dedicated public emergency telephone number, 13 13 52. Leaks reported by the public are attended to in accordance with Call Centre Work Instruction (CCT WI001)[221]. Upon confirmation of a leak, it is classified based on the perceived hazard and ATCO Gas Australia will initiate the appropriate repair work as per the leaks Leak Classification.
3.16.1 Leakage Surveys and Leakage Detection 3.16.1.1 Leak Detection and Leak Prevention Controls Leak detection and leak prevention measures for the ATCO Gas Australia GDS include: • leakage surveys of above and below ground assets; • odorised gas to enable detection of leaks by ATCO Gas Australia personnel during maintenance and meter reading activities as per Site Setup (SWI SSU 001)[222]; • Pipeline patrols conducted for Pipelines by ATCO Gas Australia personnel; • DCVG reviews conducted by ATCO Gas Australia personnel; and • CP checks to verify Pipeline integrity in accordance with the Asset Class Plan – Pipelines, Mains and Services (AST PL00009) • Pressure testing during commissioning activities to ensure constructed pipework is managed in accordance with procedures. • Quarterly meter reading. Underground gas leaks are investigated and detected in accordance with Locating Underground Gas Leaks (SWI GE 002) and LPG Networks Leak Survey and Detection (SWI LPG 002). Leak classification is assessed in accordance with procedures described in section 3.16.1.3. 3.16.1.2 Leak Survey The Leak Survey is a programmed maintenance activity that is in accordance with ATCO Gas Australia Asset Class Plans, with the outcomes of the Leak Survey FSA determining the assets, frequencies and locations for leak survey. The ATCO Gas Australia GDS is leak surveyed every 5 years along with additional requirements for higher risk locations and various asset types such
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as unprotected metallic mains or multistorey buildings. This activity is conducted as per Leak Survey Motorcycle (SWI MA 001)[223], Natural Gas Networks Leak Survey and Leak Detection (SWI MA 008)[224] and Leak Survey Multistorey Buildings (SWI MA 009)[225]. Leak survey for Pipelines includes leak survey of the immediate area surrounding any valve and regulating facilities with exposed pipe work and fittings (e.g. PRS sites). Leak survey is conducted in conjunction with maintenance activities detailed in the Asset Class Plan and scheduled to occur approximately once every 4 months on Regulator and Meter Sets with inlet pressures greater than 350kPa. Records of these surveys are maintained in ERP. Leak Surveys for the entire length of Pipelines are conducted every 5 years. The leak survey frequency for the GDS operating below 1050kPa is based on AS 4645 requirements. A Leak Survey Review FSA (TCO RP0246) has determined the survey frequency for asset classes and the outcome of the FSAs are reflected in the Asset Class Plan – Pipelines, Mains and Services (AST PL00009). The FSA takes into consideration all location specific conditions such as Low activity risk areas, High density community-use areas, the Perth CBD and City Centre Areas and has assessed that action is required to review leak survey requirements. Asset Material related risks were also assessed in the FSA such as CI, GI and unprotected steel Mains. The Albany network is leak surveyed in accordance with LPG Networks Leak Survey & Detection (SWI LPG 002)[226] and the Asset Class Plan – Pipelines, Mains and Services (AST PL00009). Leak survey frequencies were assessed as part of the Albany LPG Network FSA (TCO RP 0199)[227]. To reduce the potential of missing significant leaks during the leak survey with the bar holing technique, the Network is also leak surveyed quarterly with surface – Flame Ionisation Detector (FID). Where a leak was found and repaired, the location is resurveyed after 28 days to reduce the potential of resultant leaks caused by work carried out on the main. Multistorey dwellings are to be leak surveyed or inspected on an annual basis as prescribed in the Asset Class Plan. During leak survey, visual inspection of the pipework will be performed to identify any locations that may be potential leaks such as pinch points, areas of abrasion, or damage. Further details relating to the leak survey on the GDS are provided in the Asset Management Plan (AA4) 2014 – 2019 (AST PL00018). 3.16.1.3 Leak Classification Leaks including those found in leak survey are classified in accordance with the Attending Gas Escapes (SWI GE 001)[228] which complies with the requirements of AS 4645 Appendix E ‘Classification of Leaks’. Leaks are investigated and actioned in accordance with Attending Gas Escapes (SWI GE 001) and LPG Networks Leak Survey and Detection (SWI LPG 002). 3.16.1.4 Post Inspection (Albany LPG Network) ATCO Gas Australia conducts site re-assessments of ATCO Gas Australia excavation activities in Albany to test the integrity of the surrounding Albany Network by surveying the area to determine if any leaks have developed as a result of those activities. Excavation site re- assessments nominally take place approximately 4 weeks after excavation.
3.16.2 Gas Leak Frequency Monitoring The number of gas leaks that are found (leakage frequency) through gas leak surveys and public reported leaks are monitored on a monthly basis in accordance with Asset Management Plan (AA4) 2014-2019 (AST PL00018).
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3.16.3 Asset Replacement Areas of the ATCO Gas Australia network have been identified to have a higher frequency of leaks. A replacement strategy has been adopted to manage these leaks instead of constant maintenance and repair. Asset replacement decisions are based on information from condition and performance assessment, monitoring and modelling. The optimised decision-making process for Mains replacement, adopted by ATCO Gas Australia, uses a quantitative Failure Modes and Effects Analysis, integrated with cost versus risk modelling. Linear-asset reliability models, representing a 1km segment of Main have been developed in Isograph’s Availability Workbench (AWB) software for unprotected steel mains. For plastic mains, ATCO Gas Australia has utilised a Mains Replacement Prioritisation (MRP) software which has been developed by DNV GL and is built upon the ESRI ArcGIS Desktop platform, utilising the power of GIS and its spatial capabilities. The software provides ATCO Gas Australia with a quantitative risk based decision support tool that enables assessment of replacement scenarios and project planning for plastic mains with a MAOP of up to 700 kPa. High risk mains identified by this tool are prioritised for replacement and intermediate risk mains are scheduled for replacement in order to be considered to ALARP. A model is a series system that uses the assumption that each of the typical components that could be present in the segment may be individually described in reliability terms so that the product of these components reflects the reliability of the segment. The segment is used to represent the characteristics of the network using that material type as a whole. Details on the replacement strategies are provided in the Asset Management Plan 2016-2020 (AST PL00003)[229].
3.16.4 Ventilation Where there is the potential for leaks or releases of gas to occur within an enclosed area, adequate ventilation is provided to prevent a build-up of a flammable atmosphere. Gas meter enclosures require having ventilation that meets the requirements of AS5601[230] while gas meter boxes have specified ventilation requirements as per Meter Boxes for AL8-18 Gas Meters (ENS TS001). Assets which are located within buildings are required to have a vent line for regulators to ensure that any vented gas is released outside the building to a safe location as defined by Ventilation Guidelines for ATCO Gas Australia Facilities (ENS GL0007)[231].
3.17 Electrical Hazard Mitigation
3.17.1 'Step’ and ‘Touch' Potentials Step and touch potentials may arise from lightning or from power line faults. The following control measures are provided: • for lightning – Work is controlled during lightning events as per Lightning Safety (TCO GL0003)[232] • for powerline faults – Personnel are required to use insulated equipment as well as equipotential earth mats when working on exposed metallic pipelines. • For working on metallic assets which have to potential to have an electrical charge, personnel are required to use a volt stick in line with Volt Stick (SWI TE 001). • For where there is a break in connection between two conducting surfaces, personnel must adhere to Continuity Bond (SWI TE 002) to prevent a shock occurring from two varying voltage potential surfaces.
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• Where exposed metallic assets are worked on, personnel must adhere to Earth Mat (SWI TE 015) to mitigate the ’step’ and ‘touch’ potential. • For cutting into abandoned mains, personnel must adhere to Proving the Status of Abandoned Gas Mains (SWI MA 005)[233] to ensure there are no electrical cables inserted in the abandoned mains.
3.17.2 Third Party Electrical Asset Review In the event that a third party wishes to construct electrical assets in the vicinity of metallic gas assets, ATCO Gas Australia requests that an electrical hazard study is conducted through the engineering enquiries process, Managing Engineering Services Enquiries (ENS WI009)[234]]. Depending on the impact from the new electrical assets, controls may be put in place to ensure ATCO Gas Australia assets are protected from electrical hazards in accordance with AS/NZS 4853 Electrical hazards on metallic pipelines.
3.18 Gas Quality and Characteristics
3.18.1 Gas Quality Specifications The gas quality specifications and requirements for Natural Gas and LP Gas supplied to consumers through ATCO Gas Australia’s GDS are specified in Part 2, Division 2 (Regulations 5, 6, 9 and 13) and Schedule 1 of the GSSS Regulations. Gas quality is monitored at selected network points within the ATCO Gas Australia GDS to verify the gas quality within the ATCO Gas Australia GDS complies with the requirements of Part 2 and Schedule 1 of the GSSS Regulations.
3.18.2 Odorisation Since neither Natural Gas nor LP Gas possess a distinctive odour in their normal state, both are combined with an odorising substance or mixture of substances to enable people to detect gas in the event of LOC or release. Regulations 6 and 9 of the GSSS Regulations defines that Natural Gas and LP Gas must be odorised by the addition to the gas of an odorant that — (c) is distinctive, unpleasant and non-persistent; and (d) when the gas is discharged, throughout that discharge indicates to a person with a normal sense of smell the presence of gas down to 1/5 the lower explosive limit in air; and (e) complies with the requirements for Natural Gas and LP Gas set out in Schedule 1. Natural Gas supplied from the DBNGP and Parmelia gas transmission pipelines are odorised by DBP and APA before entering the ATCO Gas Australia network at their DBNGP or Parmelia gate stations (also referred to as meter stations) immediately upstream of entry point into ATCO Gas Australia’s GDS. Natural Gas supplied by APA’s GGP and Parkeston Power Station gas lateral is odorised by APA; however ATCO Gas Australia operates its own odorant direct injection facility at PRS020 for its Kalgoorlie GDS to assure odorant concentrations comply with the Regulations 5, and 6, and Schedule 1 of the GSSS Regulations. LPG supplied to the Albany LPG Storage Facility for reticulation into the Albany LP Gas Network is supplied by a third party through a service agreement between the LPG supplier (currently
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Elgas) and the gas retailer, Alinta Energy (the owner of the LPG). The LPG supplied is odorised by the LPG manufacturers from which the LPG supplier purchases LPG for transportation to and delivery into the Albany LPG Storage Facility. Natural Gas and LP Gas supplied within ATCO Gas Australia’s GDS contain odorant or odorant mixtures as defined in Table 3-8.
Table 3-8: Odorant, Odorant Mixtures
Gas Type Gas Supply Area Odorant Coastal Gas Supply Area – Geraldton, Nominally 70% Tertiary Butyl Perth Metropolitan areas, Harvey, Mercaptan (TBM) and 30% Iso- Bunbury and Busselton, but excludes the propyl Mercaptan (IPM) Pinjarra sub-network) Natural Gas 60-70% TBM, 18-30% IPM and Pinjarra sub-network <22% Tetrahydrothiophene (THT) Goldfields – Esperance Gas Supply Area Nominally 70% THT and 30% – Kalgoorlie GDS TBM LP Gas Great Southern Gas Supply Area – Ethyl Mercaptan (>99%) Albany GDS
3.18.3 Gas Quality Monitoring Natural Gas and LP gas quality is monitored at selected network points within the ATCO Gas Australia GDS to verify the gas quality within the ATCO Gas Australia GDS complies with the requirements of Part 2 and Schedule 1 of the GSSS Regulations. Gas quality monitoring periodic sample locations, periodic sampling frequency, sampling and testing methodologies are defined in the following documents: • Network Gas Quality (TCO PR0011)[85], • Gas Analysis and Reporting (NCO PR0010[86], • Asset Class Plan – Pipelines, Mains and Services (AST PL00009). • Collection of Natural Gas and LPG Samples (SWI AN 001)[87] • Odorant Analysis Using Gastec Tubes (SWI AN 002)[88] • Odorant Analysis Using Odor Handy Plus (SWI AN 003)[89] • ATCO Gas Australia Gas Quality Update (NCO PR0015)[90] ATCO Gas Australia has an interconnection agreement with the gas transmission operator APA defining the specifications with which APA is to conform for gas they supply into the Perth north metropolitan sub-network. In addition, both the gas transmission operators DBP and APA have obligations under the Gas Supply (Gas Quality Specifications) Regulations 2010[91] that are broadly equivalent to the gas quality requirements under the GSSS Regulations. ATCO Gas Australia receives daily Natural Gas compositional and heating value results from DBP and APA and monitors the data to verify compliance to Regulation 5(2)(a) and (d) of the GSSS Regulations. The minimum gas quality monitoring periodic sampling specifications are defined in Table 3-9, Table 3-10 and Table 3-11.
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Table 3-9: Periodic Sampling to Test Effectiveness of Odorisation
Minimum Min. Region Odorant Sampling Criteria 7 Frequency No. Perth A sample at sufficient number of locations to verify adequacy of Monthly 6 Metropolitan odorisation at gate stations feeding into Perth Metropolitan North North is to be taken per month. Perth A sample at sufficient number of locations to verify adequacy of Monthly 6 Metropolitan odorisation at gate stations feeding into Perth Metropolitan South South is to be taken per month. Kalgoorlie A minimum of one (1) location is to be sampled per month Monthly 1 Geraldton A minimum of one (1) location is to be sampled per month Monthly 1 Bunbury A minimum of two (2) locations are to be sampled per month Monthly 2 Albany LP Monthly 2 A minimum of two (2) location is to be sampled per month Gas Network Note7 All GDS selected periodic odorant sample locations are to be sampled and tested at least once over a three (3) month period.
Table 3-10: Natural Gas Monitoring Requirement (excluding Odorant)
Minimum Min. Location and Criteria Natural Gas Quality Parameter Frequency No. HHV and Wobbe Index as calculated from Six Monthly 1 Natural Gas compositional analysis (hydrocarbon and inert gases) and calculated relative density Perth Metropolitan North PRS Oxygen Six Monthly 1 nominated location Kalgoorlie PRS020 Hydrogen sulphide Six Monthly 1 Total sulphur Six Monthly 1 Water dewpoint and calculation of water Six Monthly 1 vapour content Hydrocarbon dewpoint Six Monthly 1 Perth Metropolitan South Six Monthly 1 HHV and Wobbe Index as calculated from nominated location downstream Natural Gas compositional analysis of Wesfarmers Kleenheat Gas (hydrocarbon and inert gases) and calculated LPG extraction plant Kwinana relative density Beach
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Table 3-11: ATCO Gas Australia LP Gas Quality Specification Compliance Testing (excluding Odorant)
Minimum Min. Location Natural Gas Quality Parameter Frequency No. Albany LPG Storage Facility Hydrocarbon compositional analysis which is in Monthly 1 – Inlet to PRS013 turn used to calculate relative density and HHV Monthly / Six 1 LPG Storage Tank 1 Hydrocarbon compositional analysis 8 Monthly LPG Storage Tank 2 Hydrocarbon compositional analysis “ 1 LPG Storage Tank 3 Hydrocarbon compositional analysis “ 1 LPG Storage Tank 4 Hydrocarbon compositional analysis “ 1 LPG Storage Tank 5 Hydrocarbon compositional analysis “ 1 LPG Storage Tank 6 Hydrocarbon compositional analysis “ 1 Note8 At least one LPG Storage Tank is to be sampled and test on a monthly basis, where each of Tanks 1 to 6 are to be sampled and tested at least once over a six (6) month period.
3.18.4 Natural Gas Composition and Properties Natural Gas comprises mainly methane with much smaller amounts of ethane, propane and heavier hydrocarbons, nitrogen, carbon dioxide and sulfur compounds. Natural Gas compositions at any time may vary within the GDS, where the compositional specification limits are bound by the requirements specified in Regulation 5 of the GSSS Regulations and Table 3.1 of AS 4564–2011: Specification for general-purpose natural gas[92]. The Wobbe Index maximum and minimum limits, Higher Heating Value maximum limit and the total Inert gases maximum limit defined in Table 3-12 are the limits defined within Table 3.1 of AS 4564–2011. The hydrocarbon compositional ranges defined in Table 3-12 are typical maximum compositional ranges but do not limit compositions outside these ranges, providing the gas complies with the specification limits defined within Table 3.1 of AS 4564–2011.
Table 3-12: Natural Gas Compositional Range
Component / Property Range Unit Wobbe Index 46.0 to 52.0 MJ/m3 HHV 37.0 to 42.3 MJ/m3 Methane 75-99 Mole % Ethane <10 Mole % Propane <5 Mole % Butane <1 Mole % Iso-butane <1 Mole % Pentane and heavier hydrocarbon(s) <1 Mole % Total Inerts (Nitrogen and Carbon Dioxide) <7 Mole %
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A summary of the key properties of Natural Gas is provided in Table 3-13.
Table 3-13: Natural Gas properties
Material Name NATURAL GAS, COMPRESSED with High Methane content
Chemical Formula CH4 (Methane) Main chemical constituent Chemical Family Hydrocarbon UN# 1971 CAS# 74-82-8 (Methane) HAZCHEM Code 2SE Dangerous Goods 2.1 Class Risk (R) Phrase R12 - Extremely Flammable Safety (S) Phrase S16 – Keep away from sources of ignition – no smoking S33 – Take precautionary measures against static discharge Physical Form Gas Boiling Point -162°C Flammability 5% to 15% (Volume in air) Limits Auto-ignition > 450°C Temperature Specific Gravity 0.6-0.7 Density 0.71 to 0.79 kg/m3 at 15°C and 101.325 kPa Stability Stable under normal conditions when not exposed to oxidants or heat Reactivity Extremely flammable, natural gas may burn or explode in a confined space when mixed with strong oxidizing agents (peroxide, chlorine, chlorine dioxide, liquid oxygen)
3.18.5 LPG Composition and Properties LP Gas reticulated within the Albany LP Gas Network in gaseous phase comprises mainly propane and minor concentrations of propene, ethane and butanes and butane. As a refined product from Natural Gas, or a petroleum refinery by-product, LP Gas compositions at any time may vary within the GDS, where the composition is bound by the requirements specified in Regulation 13 of the GSSS Regulations. The requirements of Regulation 13 of the GSSS Regulations apply only to the gas that is reticulated within the GDS; whereas the compositional analyses for each of the LPG Storage Tanks may differ from the GDS compositional analysis which is monitored at the inlet to PRS013 (refer to Table 3-11). The LP Gas compositional ranges defined within Table 3-14 with reference to Propane, Propene and heavier hydrocarbons are ranges and maximums for which ATCO Gas Australia is able to
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assure the LP Gas composition complies with Regulation 13 of the GSSS Regulations and also assures the third party LPG supplier is supplying LPG that complies with the requirements of AS 4670-2006 Commercial propane and commercial butane for heating purpose[261].
Table 3-14: LP Gas Compositional Range
Component Range Unit Ethane < 5 Mole % Propane 75 – 99.5 Mole % Propene (also referred to as Propylene) < 15 Mole % Sum of Propane + Propene > 90 Mole % Butanes (Iso-butane, n-butane) < 7.59 Mole% Mole % Butanes and heavier hydrocarbons < 7.5 Mole% Mole % Butenes, Dienes plus Pentanes and heavier < 0.3 Mole% Mole % hydrocarbons Note9 The practical maximum for total Butanes concentrations is 7.5 mole%, minus the concentrations Butenes and Pentanes and heavier hydrocarbons. A summary of the key properties of LP Gas is provided in Table 3-15.
Table 3-15: LP Gas properties
Material Name HYDROCARBON GAS MIXTURE, COMPRESSED, N.O.S.
Chemical Formula C3H8 (Propane) Main chemical constituent Chemical Family Hydrocarbon UN# 1964 CAS# 68476-85-7 (as it refers to Liquefied Petroleum Gas 76-98-6 (as it refers to Propane) HAZCHEM Code 2SE Dangerous Goods 2.1 Class Risk (R) Phrase R12 - Extremely Flammable Safety (S) Phrase S16 – Keep away from sources of ignition – no smoking S33 – Take precautionary measures against static discharge Physical Form Gaseous Vapour Boiling Point -42°C Flammability Limits 2.1 – 9.5 % Auto-ignition > 493°C Temperature Specific Gravity 0.509
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Density Propane: Liquid (at 15°C) = 510 kg/m3, Gas (at 101 kPa & 15°C) = 1.86 kg/m3 Stability Stable under normal ambient conditions of use Reactivity Extremely flammable, incompatible with oxidising agents, acids, and strong alkalis.
3.18.6 Natural Gas and LP Gas Hazardous Properties Natural Gas and LP Gas are both colourless and odourless gases; however both are odorised with a distinctive pungent mercaptan odour within the GDS to allow for their detection in the event of a loss of containment. Natural Gas and LP Gas are both extremely flammable gases which in the event of a loss of containment can form flammable and explosive mixtures with air which can readily ignite at normal temperatures. Natural Gas and LP Gas are both non-toxic; however they present a significant health hazard as they are each a simple asphyxiant, acting by displacing oxygen in the breathable atmosphere, leading potentially to unconsciousness or death. In the event of a loss of containment of either Natural Gas or LP Gas, the lower flammability limit in air of methane, or propane/butane, respectively, would likely be exceeded before suffocation can occur. However in the event of a release of either Natural Gas or LP Gas, there is a possibility that both an oxygen-deficient and explosive atmosphere may result. Natural Gas is lighter than air therefore in the event of a release Natural Gas may readily disperse and spread long distances. LP Gas is heavier than air, and can collect in low lying areas and travel downwind or downhill to sources of ignition. The flammable zone may extend beyond the visible vapour cloud.
3.18.7 Transportation of Alternative Fuel Gases ATCO Gas Australia is committed to providing safe, environmentally and economically sustainable energy solutions for Western Australia. ATCO Gas Australia has and will continue to work with gas distribution and energy network industry bodies, standards committees and regulatory authorities with regards to the potential for transition to the transportation of alternative low emissions fuel gas mixtures. This includes fuel gas mixtures with prescribed maximum amounts of renewable gasses such as hydrogen or biogas.
3.19 Legislation and Business Practices Activities involving ATCO Gas Australia GDS construction, operation and maintenance are monitored to assure they meet the requirements of relevant current legislation, standards, codes of practice and ATCO Gas Australia’s SMS. Where current practice deviates from a requirement of legislation or a standard or code, a risk assessment will be conducted to demonstrate that the practice will result in equivalent or higher level of safety. Employees and contractors have a legal obligation to comply with their duty of care, and must undertake activities on the ATCO Gas Australia GDS, lawfully and in accordance with this Safety Case, ATCO Gas Australia instructions, and relevant legislative standards, and act to maintain the integrity of the ATCO Gas Australia GDS. The ATCO Australia Corporate Services and Legal team, has compiled and maintains a register of its legal obligations, known as the Master Obligations Register (REG RG001)[235], with which it monitors compliance with those obligations, including those relating to the Safety Case.
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3.19.1 Changes to Legislation and Business Practices The Technical Compliance team, HSE and ATCO Australia Corporate Services and Legal teams monitor relevant legislation, standards, codes of practice and business practices so that ATCO Gas Australia continues to operate safely and lawfully, and that there is minimal disruption to business continuity from pending changes to legislation and practices. ATCO Gas Australia employees have access to publicly available World Wide Web based sources of information including the State Law Publisher and access through the ATCO Australia Corporate Services and Legal and HSE teams to specialist subscription services for prompt notification of changes in legislation (Lawlex). ATCO Gas Australia is represented on Standards Australia committees, which are responsible for revision of standards relating to construction, operation and maintenance of gas distribution systems. This assists ATCO Gas Australia in maintaining awareness of changes to standards relevant to the ATCO Gas Australia GDS, and also contributes to ATCO Gas Australia’s awareness of current industry best practices.
3.20 Audit and Inspection It is an ATCO Gas Australia business objective to demonstrate that the SMS used for the ATCO Gas Australia GDS, and described in this Safety Case, is a robust system for managing risk associated with pipeline operations and is being implemented as planned, and continually improved. Periodic verification that the SMS is being adopted in the daily operation of the ATCO Gas Australia GDS, and regular review to measure its effectiveness in meeting ATCO Gas Australia policies and objectives is conducted.
3.20.1 Audit 3.20.1.1 General Auditing is conducted in accordance with Technical Compliance Auditing (TCO PR0005)[236] and includes Safety Case audits and independent audits as required by ATCO Gas Australia.
3.20.1.2 Safety Case Audit The GDS Safety Case will be audited in accordance with the requirements of regulation 38 of the GSSS Regulations in particular: • reviewing the Safety Case for its adequacy and appropriateness having regard to any changes in the ATCO Gas Australia GDS since a Safety Case audit was last conducted; • assessing whether there continue to be properly trained and equipped personnel available to implement the procedures set out in the safety case and that the following are still in place; • assessing whether the measures necessary to “(i) prevent hazardous events identified in the safety case from occurring” are still in place; and • the measures necessary to “(ii) to protect consumers, the public, employees, plant, equipment and the environment, should such events occur” are still in place.
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3.20.2 Inspection Site and general inspections are conducted to monitor and demonstrate compliance with procedures and instructions, promote continuous improvement in the workplace environment, to identify workplace hazards and to indicate corrective actions required to control the hazards. The procedure Work Site and General Inspections (TCO PR0001) outlines the requirements for site and general inspections. Inspection checklists include housekeeping, equipment, conditions, general and contractor compliance with specified safe work procedures, and general safety and occupational hygiene. Workplace inspections are recorded and signed off by the person undertaking the inspection and responsibility for any corrective action is assigned. Inspections are conducted in accordance with the relevant inspection checklist, such as Checklist Site Inspection – Disconnect Gas Service at Main (TCO PR0001 RF13)[237].
3.20.3 Action Tracking Audit, emergency management and incident investigation corrective action tracking is conducted in accordance with GDS Risk Register (Action Tracking) (TCO PR0008), using Technical Compliance Document Register (TCO RG0003) as the action tracking spreadsheet. This is tracked as described in Section 3.5.9. Worksite and general inspection corrective action tracking is conducted in accordance with Work Site and General Inspections (TCO PR0001) and the records of actions is kept in ERP EHS.
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4. FORMAL SAFETY ASSESSMENT
4.1 Formal Safety Assessment Process The Formal Safety Assessment is a review of the risks related to each asset class making up the composition of the GDS described in Section 2.2 as well as risks associated with network operational activities. The ATCO Gas Australia Technical Compliance Risk Register (TCO RG004) documents the risks related to each asset class or activity and acts as a map to the relevant FSA. This register includes FSAs conducted by ATCO Gas Australia in accordance with Technical Compliance Risk Management Guideline (TCO GL0001), as described in Section 3.5 such as: • AS 2885 Safety Management Study, refer to sections 3.5.5 and 3.5.8; • Natural Gas Network FSA and Albany LPG Network FSA, refer to section 3.5.6; • HAZOPs of pressure regulating and metering facilities with inlet pressures of 350kPa and greater, refer to Section 3.5.7; • AS/NZS 4645 Deviation from Standard FSAs, refer to section 4.4; and • AS/NZS 4645 HAZIDs of prescribed activities, refer to section 3.5.11. • Semi-quantitative risk assessments, refer to section 3.5.8. The technical compliance risk register provides a link to the various FSAs that have assessed each of the asset classes and types and prescribed activities as summarised below and in Table 4-1 and Table 4-2. • Further details of FSA Significant Risks are described in Section 4.2 • Risk controls implemented for each of the Section 4.2 Significant Risks are described in Section 4.3. • Where through FSA, ATCO Gas Australia has deviated from the AS/NZS 4645 ‘acceptable means of compliance’, the specific deviations and acceptability validation are summarised in Section 4.4. Principal assets risk FSAs conducted and referred to within this Safety Case are: • Natural Gas Network FSA (TCO RP 0194) • Albany LPG Network FSA (TCO RP 0199) • Multi-storey and Multi-occupancy FSA (TCO RP 0231) • AS2885 Safety Management Studies Class 300 and 600 Pipelines (TCO RP 0245) • Leak Survey FSA (TCO RP 0246) • High Rise Strategy FSA (TCO RP 0193) • Supply Risk Assessment Northern Networks (TCO RP 0209) • Class 300 and 600 Pipelines Semi-quantitative Risk Assessment (TCO RP 0278) • Supply Risk Assessment – Southern, Eastern and Regional Networks (TCO RP 0283)
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Table 4-1: Risk Register Asset Risk – Summary of Asset Types Assessed ASSET RISKS ASSET ASSET TYPES ASSESSED Pipelines Steel, PE Mains Steel, Cast Iron, Galvanised Iron, PE, uPVC Services Steel, Cast Iron, Galvanised Iron, PE, uPVC, Copper Meters Domestic, Commercial, Non-Billing Regulators Domestic, Commercial, MPR, HPR, PRS Odorant Facility Refer to sections 2.2.6 and 2.3.4
The principal GDS activity risks FSAs conducted and referred to within this Safety Case is: • AS/NZS 4645 Prescribed Activities FSA (TCO RP 0249) • Commissioning Mains FSA (TCO RP 0202)
Table 4-2: Risk Register Activity Risks – Summary of Asset Types Assessed ACTIVITY RISKS ACTIVITY ASSET TYPES ASSESSED Commissioning Venting Purging Pipelines Flaring Mains Decommissioning Services Installation Regulators Testing Maintenance
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4.2 Significant Risks The FSAs identified common risks that were repeated across the different ATCO Gas Australia GDS assets classes. Seventeen (17) common risk categories have been assessed by FSA as being ‘intermediate’ or ‘high’. These risks are deemed to be Significant Risks and are described in sections 4.2.4 to 4.2.14 with the following information: • Asset classes impacted by the Significant Risk, and • Summary of the controls in place to manage these risks, to ‘intermediate’ and ALARP, or a lower level of risk.
Table 4-3 Significant Risks and the relevant asset/activity
# Significant Risks Mains Meters Services Pipelines Activities Regulators
1 Loss of Containment from Physical Damage9 2 Loss of Containment from Material Failure9 3 Loss of Containment from Corrosion9 4 Loss of Containment in Perth CBD 5 Loss of Containment in Multistorey Buildings10 6 Loss of Containment in Multi-occupancy Dwellings10 7 Loss of Containment in High Risk Locations10 8 Loss of containment from Mains entering private property 9 Loss of Containment inside Buildings11 10 Loss of Containment in Albany LPG network 11 Loss of Containment from Unprotected Metallic Main 12 Electric Shock 13 Loss of Containment from M6WA domestic meter plug failure 14 Gas Supply Interruption Note9 These loss of containment events apply to the location class which is considered to be representative of the majority of the network which is Rural/Residential. Note10 Refer to Definitions, section 1.10. Note11 Refers to services and commercial meters inside buildings being used for commercial operations.
4.2.1 Loss of Containment due to physical damage The main causes of loss of containment due to third party damage included: • Third Party Impact (Excavators, Augers, HDD, hot works) • Ground Disturbance (Tree roots or adjacent indirect earth works) • Natural events (seismic, flooding) • Excessive loads on the pipe
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The majority of the GDS consists of pipelines, mains and services located adjacent to other utilities that carry out works including excavation, augering and horizontal direction drilling. When conducting these works, physical damage may occur and has been identified as a significant risk to people for all asset types. Physical damage to the pipeline may also occur from natural events or having excessive loads placed on GDS assets. The principal driver for physical damage being a significant risk is from third party impacts. To reduce third party impacts from excavation, and horizontal direction drilling ATCO Gas Australia has implemented a variety of controls based on the requirements of the network and transmission standards; AS/NZS 4645.1 and AS 2885.1. Controls in place to manage the risk of third party impacts are as follows and further detailed in sections 4.3 and 3.11. • DBYD • HP Notification • Third Party awareness (refer to Third Party Pipeline Damage Prevention Manual, NCO MA00001) • Material Selection • Pipeline Marker Signs • Marker Tape • Depth of Cover • Pipeline Patrols • Concrete encasing • Sleeving • Slabbing • Leak Survey • Odorant and Gas Quality • Faults, Incidents, Emergency Response.
4.2.2 Loss of Containment due to Material Failure The cause of material failure was assessed as a significant risk which included causes such as: • Overpressure • Material Degradation
4.2.2.1 Overpressure An overpressure can occur on the GDS either from failure of an ATCO Gas Australia pressure regulator, or upstream transmission operator pressure regulator. The specification breaks on the GDS occur at pressure regulation devices thus a failure of such a device has the potential to overpressure the downstream pipe and equipment on the GDS. This overpressure and failure of downstream assets imposes significant risk to people and gas supply. Failures of an ATCO Gas Australia regulator, such as PRS or HPR, could result in downstream equipment failing or venting due to overpressure. This has been controlled with the installation of OPSOs at pressure regulating facilities where the inlet pressure, exceeds 200kPa. OPSOs reduce the consequence of an overpressure event as the downstream network will be protected.
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Controls to prevent or reduce the frequency of the failure of pressure regulation on the GDS were identified for these risks – • PRS and HPR Design and control failure redundancy in-built into design • Pressure relief valves to relieve pressure from the downstream network • Preventative maintenance which includes checking regulators are in working order on a regular interval • Training and competency Failure of a Gate Station, owned and/or operated by transmission petroleum pipeline operators and regulated by the Department of Mines, Industrial Regulation and Safety (Resources Safety), is a risk which is outside of the scope of ATCO Gas Australia. Transmission petroleum pipeline operators have provided ATCO Gas Australia with documentation confirming that Gate Stations are designed and operated in accordance with the requirements of AS 2885 and the risk of a Gate Station failure has been assessed by the transmission operators as ‘intermediate’ and ALARP. Although ATCO Gas Australia has no control over the transmission operator’s gate station, mitigative controls are in place to manage a gas release such as – • Physical separation - HPR cabinets reduce momentum of gas release and the potential for ignition sources to be at the release point; or PRS Fencing reduces potential for foreign ignition sources and exclusion of the public from the PRS. • Alarms (high pressure response) have the potential to notify the control room staff to respond to an overpressure event. • Emergency Response plan includes the deployment of resources to manage a potential event. 4.2.2.2 Material Degradation Loss of containment due to material failure from degradation occurs throughout ATCOs network as the assets age. ATCO has used MRP software which determines the risk for sections of plastic mains by taking into consideration factors such as those shown in Table 4-4.
Table 4-4: Factors considered in MRP tool to determine risk of asset (PE &PVC Mains ≤700kPa)
Information Type Model Inputs
General Asset Information Material type, nominal diameter, length, age, pressure, joint types, wall thickness. Construction Quality Tube material quality, soil preparation quality, construction quality, Factors depth of cover, connection density, connection quality, branching quality, repair quality. Long Term Interference Soil type, pollution, sharp stones, soil stability, tree root presence, Factors ground water, traffic intensity, proximity to underground electrical cables. The software has inbuilt project planning / scenario analysis capabilities that develop replacement strategies to efficiently meet risk-based targets. Annual review and project planning based on MRP is undertaken in two phases:
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‘High’ risk mains are selected as the highest priority mains for replacement. It is anticipated that once these mains have been replaced, the risks associated with these mains will be reduced to an acceptable level. ‘Intermediate’ risk mains are selected for further analysis which feeds into the asset replacement strategy depending on whether or not the risk has been assessed as ALARP. Annual project planning selects mains within the ‘intermediate’ region for replacement, after which the risk is reduced to an acceptable level. Remaining mains within the ‘intermediate’ zone are considered to be ALARP providing design, construction, operation and maintenance is in accordance with the current requirements of AS/NZS 4645. These mains are then reviewed annually with updated network data input to the model, to ensure any mains with intermediate risk moving towards the high region are prioritised for replacement before this occurs. As part of the overall strategy, suburbs with the highest overall risk are prioritised for replacement first, with the aim of reducing the overall suburb risk to an acceptable level.
4.2.3 Loss of Containment Due to Corrosion Corrosion can occur on metallic assets which can lead to a loss of containment. There are a range of corrosion protection measures undertaken by ATCO Gas Australia to protect the metallic assets identified in the Asset Class Plan - Cathodic Protection Systems (AST PL00006). Corrosion was identified as a cause of the following significant risks: • Corrosion resulting in loss of containment in the CBD which escalates to ignition of natural gas in an occupied building is assessed. • Corrosion on high carbon steel pipelines (with MAOPS greater than 1050kPa), either internal or external corrosion, and the loss of containment results in loss of supply to a significant number of customers due to the need to isolate and repair. The natural gas distributed through the GDS is classified as a dry, sweet gas low in sulphur, which if present in appreciable concentrations could form an electrolyte and electrochemical potential allow for corrosion within steel pipelines. The controls that prevent corrosion from occurring are: • Cathodic protection is provided through either sacrificial anodes or impressed current across the high pressure steel network and the sacrificial anode on the city high pressure network • Pipe coating requirements and technologies have changed over time, of which are providing a barrier from moisture and air contacting the steel pipe. • Gas quality monitoring, which monitors for gas quality changes against prescribed gas quality specifications and potential changes to the corrosion risk. The controls that mitigate against the escalation of the consequences from a small corrosion loss of containment event, such as a reported smell of gas are: • Odorant and odorant concentrations gas quality monitoring to assure third parties, or members of the public are able to detect the presence of a gas leak. • Leak survey high carbon steel pipelines, or metallic mains and where leaks are detected, leak repair (refer to Faults, Incidents, Emergency Response). • Planning for and maintenance of pressure regulating facilities at defined intervals, which includes inspection of the integrity of the facility.
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• Faults, Incidents, Emergency Response include the deployment of resources to identify the extent and begin resolving the incident.
4.2.4 Loss of Containment in Perth CBD A loss of containment event within the Perth CBD has the potential to be a significant risk to people and to a lesser extent, gas supply. The principal risk causal factor is third party damage to GDS assets, which include high carbon steel pipelines with MAOP of 1900kPa, high carbon steel, PE, and short sections of copper mains with MAOP of 350kPa and pressure regulating facilities. The risk within the Perth CBD is more significant than outside the CBD due to population density, commercial and tourism building occupancy periods and the potential for congregation of high numbers of people within multiple CBD locations. Controls to manage risks of loss of containment in the Perth CBD include: • DBYD • HP Notification • Third Party awareness (refer also to section 3.11.5and 4.3) • Material Selection • Corrosion protection • Pipeline Patrol • Pipeline Marker Signs • Leak Survey • Odorant and gas quality monitoring • Isolation Valves • Faults, Incidents and Emergency Response To further reduce risk within the Perth CBD, the CBD Risk Reduction Project includes the construction of new pipelines and HPRs to reduce GDS operating pressures and provide additional gas supply backup.
4.2.5 Loss of Containment in Multi-storey Buildings 4.2.5.1 Multi-storey Buildings with Internal GDS Assets and Built prior to 2013 A loss of containment event within Multi-storey Buildings has the potential to be a significant risk to people. The principal risk causal factors are third party damage, e.g. from building maintenance and renovations, inadequate ventilation and material integrity failure. The GDS assets within Multi-storey Buildings include mains, services and consumer gas meter assemblies (which includes the regulator and meter). The FSA assessed that the risk related to gas infrastructure assets within Multi-storey Buildings was reduced from the previous 2011 Gas Distribution Network Formal Safety Assessment (TCO RP 0008)[240] from ‘high’ to ‘low’. This risk reduction is due to the implementation of the Multistorey Building Project[256] which assesses that all gas infrastructure assets within Multi- storey Buildings meet the current requirements of AS/NZS 4645. Controls to manage risks of loss of containment in Multi-storey Buildings include:
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• Material Selection – Galvanised/cast iron was replaced with copper or steel which is less prone to damage from impact • Ventilation - Mains and services that were typically in a service duct, or meter assemblies within unsatisfactory locations, were either removed or ventilation upgraded to meet the current requirements of AS/NZS 4645. • Odorant and Gas Quality - Detecting the leak before it escalates comes from the public identifying gas due to the odorant, • Leak Survey – Survey of Multi-storey Buildings with internal assets occur as per Asset Class Plan – Pipelines, Main and Services (AST PL00009) This risk has been reduced to an acceptable level, where the Multi-storey project (completed in 2016) gas infrastructure assets meet the current requirements of AS/NZS 4645. 4.2.5.2 High Rise (Multi-storey) Buildings with Purpose Built Internal GDS Assets The High Rise Strategy FSA (TCO RP 0193) assesses the strategy for constructing new multi- storey buildings with internal GDS assets within the building, as described in the Waterbank Development Project[257]. This strategy controls risk to an ‘acceptable level’ (‘low’, or ‘negligible’) and includes: • verification of the adequacy of ventilation; • having where practicable dedicated ducts for the internal GDS assets, or otherwise design as approved by ATCO Gas Australia; • leakage surveys; • assurance that the internal GDS assets are accessible for inspection and maintenance.
4.2.6 Loss of Containment in Multi-occupancy Dwelling A loss of containment event within Multi-occupancy Dwellings has the potential to be a significant risk to people. The principal risk causal factors as per Multi-storey Buildings are third party damage, e.g. from building maintenance and renovations, inadequate ventilation and material integrity failure. The GDS assets within Multi-occupancy Dwellings include mains, services and consumer gas meter assemblies (which includes the regulator and meter). This risk is currently assessed as not being ALARP, requiring specific Multi-occupancy Dwelling review and assessment to determine if further risk reduction controls need to be implemented to further reduce risk to ALARP, or a lower and acceptable level. A Multi-occupancy Dwelling project[238] is currently in place to assess, prioritise and remediate as required to assure internal or external mains, services and gas meter assemblies meet the current requirements of AS/NZS 4645. Controls to manage risks of loss of containment in Multi-occupancy Dwellings include: • Material Selection – Where the assessments identify Galvanised/cast iron mains/services they are to be replaced with copper or steel pipe, which is less prone to damage from impact. • Ventilation - Where the assessments identifies mains/services in services ducts, or gas meter assemblies within unsatisfactory locations, they are to be either be removed, or if ventilation is assessed to be inadequate, ventilation upgraded to meet the requirements of AS/NZS 4645.
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• Odorant and Gas Quality - Detecting the leak before it escalates comes from the public identifying gas due to the odorant, Where the Multi-occupancy Dwelling project remediates internal and external gas infrastructure assets to meet the requirements of AS/NZS 4645, the risk will be reduced to an acceptable level.
4.2.7 Loss of Containment in High Risk Location A loss of containment event from principally uPVC and PE mains within High Risk Locations has the potential to be a significant risk to people. The risk to people is more significant in High Risk Locations due to higher population density, typically reduced main to building distances in conjunction with the potential for ground surfaces being sealed/semi-sealed and therefore increased risk of leak tracking towards buildings. The principal risk causal factors are third party damage, where the damage has not been reported, other types of physical damage, or material integrity failure (main, pipe connectors, or fittings). Controls to manage risks of loss of containment in the High Risk Locations include: • Material Selection and management, which includes validation of the integrity of non- standard fittings installed within the GDS (refer to Non-Standard Fittings FMEA (TCO RP 0228)[239]) • Leak Survey, • Asset Planning and Asset Replacement (refer also to section 3.16.3 in reference to the application of the MRP software) • Odorant and Gas Quality, • Faults, Incidents and Emergency Response; and, • Network Isolation.
4.2.8 Loss of containment from mains entering private property Mains in private property within the GDS are installed under internal private (ungazetted) roads in the same manner mains in the road reserve are constructed. Private property developments include developments that are freely accessible to residents and the public as well as ‘gated’ communities with limited access. These mains are currently not subject to leak survey. The Leak Survey FSAs (TCO RP 0246) assessed that further action is required to determine leak survey requirements.
4.2.9 Loss of Containment in Buildings A loss of containment event within buildings has the potential to be a significant risk to people. This risk specifically refers to gas services and commercial meters, or meter sets located within buildings (including below floor level car parks, or rooms/spaces where commercial appliances are installed). This risk is currently assessed as not being ALARP, requiring specific review and assessment of commercial meters/meter sets within buildings to determine if further risk reduction controls need to be implemented to further reduce risk to ALARP, or a lower and acceptable level. The principal causal factors are: • Vehicle impacts of meters and meter sets located in basement car-parks • Building renovations impacting meters within buildings
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• Material defect resulting in loss of containment that escalates to ignition of gas contained within the occupied building • Corrosion resulting in loss of containment that escalates to ignition of gas contained within the occupied building The Meters Compliance Project assesses, prioritises and remediates as required commercial meters/meter sets in buildings against the current requirements of AS/NZS 4645. Controls to manage risks of loss of containment of commercial meters/meter sets within buildings include: • Physical Protection - Protecting against impacts, e.g. Bollards (meter sets), and the protection of meters in Meter Boxes. • Corrosion protection • Odorant and Gas Quality, • Faults, Incidents and Emergency Response. • Quarterly meter reading
4.2.10 Loss of Containment in Albany LPG Network Properties of the reticulated LP Gas are distinctly different to that of reticulated Natural Gas in that LP Gas is a heavier than air gas compared to Natural Gas which is a lighter than air gas. This property difference means that the lower LP Gas buoyancy reduces the gases ability to rise through the soil into the air and increases its leak tracking potential. A loss of containment of LP Gas event in the Albany Network has the potential to be a significant risk to people and also to a lesser extent gas supply.The principal causal factors (predominantly for the risk to people) are: • Physical (predominantly third party impact) and unreported damage to, or material failure of Bolted Compression fitting with a latent (delayed impact) leak • Physical (predominantly third party impact) and unreported damage to, or material failure of uPVC or PE Mains, or Services (including Service Riser) with MAOP 20kPa with a latent leak • Risk increasing factor includes leak tracking through sleeved service. • Third party damage to PRS013 (predominantly vehicle/mobile plant impact) • Network over-pressure from failure of PRS013 pressure regulators and OPSO devices • Physical damage/third party impact, or material failure due to excessively cold temperatures impacting the principal PE DN225mm Trunk main and its downstream immediately connected DN195mm and DN100mm uPVC mains outside the Albany LPG Plant Controls to manage risks of loss of containment in the Albany Network include: • Material Selection – Removal of specific types of Bolted Compressions fittings and replacement with fully solvent welded, or electro-fused pipe, or approved transition fittings, approved pipe and PRS013 materials; • PRS Design (PRS013 regulator design; pressure relief valve, active/monitor regulator, including over-pressure shut off); • Asset and Operational Planning;
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• Physical Protection – Bollards; • Depth of Cover; • Pipeline Marker Signs (trunk mains outside Albany LPG Plant) • Marker Tape; • Preventative Maintenance • Training and Competency – With respect to installation, maintenance and repair; • Third Party Awareness Programs; • Dial Before You Dig; • Leak Survey (Albany) (Albany has an enhanced leak survey program in accordance with LPG Networks Leak Survey & Detection (SWI LPG 002), that assures so far as is reasonably practicable leaks can be identified and repaired before the size and scale of the leak escalates into having the potential for more significant consequences); • Odorant and Gas Quality; and, • Faults, Incidents and Emergency Response.
4.2.11 Loss of Containment from Unprotected Metallic Main The unprotected metallic mains asset class covers all metallic pipes, not protected by sacrificial, or impressed current cathodic protection system. The steel pipes were manufactured with coal tar enamel coating ranging in size from 20mm to 380mm and installed in the ATCO Gas Australia GDS commencing circa 1915. Due to their age, the coating on many of these pipes is deteriorating and has reduced effectiveness, potentially leading to crevice corrosion sites and pitting resulting in perforated leaks. A loss of containment event from unprotected metallic mains has the potential to be a significant risk to people. This risk is currently assessed as not being ALARP, where upon completion of the Metallic Mains Replacement project the risk will be eliminated. To date the higher risk unprotected metallic mains in higher density populated areas have been removed and replaced with predominantly PE mains. With respect to suburbs with higher proportions of the remaining unprotected metallic mains the leak survey interval is 3 years to continue to monitor the asset condition.
4.2.12 Electric Shock Whilst working near, or on metallic ATCO Gas Australia assets (high carbon steel pipelines, metallic mains and services, pressure regulating and metering facilities, including the domestic gas meter assembly and meterbox) electric shock is a significant risk to ATCO Gas Australia personnel. The principal causal factors are direct exposure to electric currents within power cables/conduits, electrical faults on the electrical supply within domestic and commercial premises or the electricity power distribution network impacting metallic ATCO Gas Australia assets, or lightning. While working with metallic pipes or equipment there is a risk of faults on the power distribution network resulting in an Earth Potential Rise on the gas network. Should an employee or contractor working on the gas network be contacting the metallic asset and the ground at the same time, an electric shock could occur. Earth Potential Rise, where the voltage difference
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between the metallic pipe and the earth develops due to fault on electrical network, is minimised through – • Separation of assets for road reserves, in which the majority the GDS is located, is defined by a committee of utility providers • Engineering Enquiry (HV Works near HP Assets) is the process for managing a known high voltage installation near the high pressure steel network, to limit the risk. • Above ground assets are separated from the metal pipeline through design • Procedures for preventing exposure to electrical sources is also achieved through use of volt sticks, continuity bonding and earth mats Further reductions in risk will be achieved through the Step Touch Mitigation Project, Facility Upgrade: Step Touch Mitigation Project[242], to progressively review, prioritise and upgrade HPRs to ensure there is sufficient earthing to mitigate step touch potential. Works in the vicinity of electrical assets had the potential for electric shock if personnel were to strike underground power utilities or mistaking underground power conduit as plastic gas pipe. The controls for preventing the strikes of electrical services during excavation are – • Road Reserve (Separation of Utilities) is the separation of assets for road reserves, in which the majority the GDS is located, is defined by a committee of utility providers. • DBYD provides details of known electrical assets. • Use of cable locators and pot holing to identify the electrical assets before excavation. In the event that personnel are required to confirm if an electrical cable is present when a conduit is found, Proving the Status of Abandoned Gas Mains (SWI MA 005) is used to prove the nature of the conduit in a safe manner.
4.2.13 M6WA domestic meter plug failure M6WA Email meter consumer meters were installed during the mid-1990s had a plastic plug to allow for adjusting the meter during refurbishment. During low flow or no flow conditions and high ambient conditions trapped gas in the meter can expand resulting in a leak at the plastic plug. A release from these meters has the potential to escalate into an uncontrolled gas leak at a dwelling and the potential for a significant risk to people. This risk is currently assessed as not being ALARP. Controls to manage the M6WA Email meter risk include: • Material selection – new meters do not have this meter design failure mode • Meter Replacement – The Replacement: M6WA Meters with Plugs Project[243] aims to replace the M6WA Email meter with meters that do not have installed plugs. Upon completion of the project, this risk is eliminated.
4.2.14 Gas Supply Interruption The significant risks involving damage to the network could also have supply consequences that result in significant gas supply related risks. An increased risk associated with loss of gas supply results from when there is a requirement to isolate the pipe for repair and there is a combination of the following scenarios: • No gas supply backup (not back-gassed) ;
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• the options for installing a bypass to maintain gas supply are limited; • there is excessive time required to achieve the bypass; or • or there is no bypass option available. The principal losses of gas supply causal factors are: • Third Party Impacts. • Water Ingress. 4.2.14.1 Third Party Impacts Refer to ATCO Gas Australia Technical Compliance Risk Register (TCO RG004) for details of the various FSA covering gas supply interruption due to third party impact and include the following FSAs • Natural Gas Network Formal Safety Assessment (TCO RP 0194)[244]. • Albany LPG Network Formal Safety Assessment (TCO RP 0199)[227]. • Specific gas supply interruption reports for high carbon steel pipelines with MAOPs greater than 1900kPa (Class 300 and 600) Refer to section 3.11 for a description of the Third Party Damage Prevention management system and section 4.3 for the significant controls listing.
4.2.14.2 Water ingress into the GDS Water ingress into the GDS can result in loss of gas supply to many customers. Causes of water in the main have been identified as faults in the water utility’s mains or services and the resulting leak/discharge impinging on GDS and wearing through the gas pipe or third party damage to both utilities. The water ingress into GDS risk to gas supply, Natural Gas Network FSA (TCO RP 0194), has been assessed as ‘intermediate’ and ALARP. Maintaining minimum separation distances between buried water and gas utilities minimise the risk of water mains leaks, or discharges impacting upon and causing failure of GDS gas mains and services. New GDS construction requirements as specified for example within Common Trench Gas Infrastructure (SWI CO 028), ‘Training and Competency’ and ‘Construction Inspection’ as the principal risk control measures for assuring so far as is reasonably practicable minimum separation distances between water and gas assets are maintained. The ‘Faults, Incidents, Emergency Response’ mitigative control combined with ‘Training and Competency’ minimise the risk of a gas supply interruption event from escalating into a ‘severe’ supply event.
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4.3 Significant Controls Table 4-5 lists the risk control measures implemented to eliminate, reduce to ‘intermediate’ and ALARP, or to an acceptable level (‘low’ or ‘negligible’) the significant risks described in Section 4.2. Additional detail about physical controls and management systems can be found in Section 2 and Section 3.
Table 4-5: Significant Controls
Title Description Documents SC Ref
Alarms The ATCO Gas Australia GDS comprises pressure Control Room Alarm 2.4.2.3 PRS and monitoring on selected regulating facilities and within the Response Procedure Regulator Sets GDS and flow monitoring at selected metering facilities. (CTR PR0004) configuration Critical and selected location pressure and flow monitoring 2.4.6 System Monitoring devices are also alarmed to provide for example alert of over-pressure, or low/no flow conditions. (Telemetry) Pressure and flow alarms in the Control Room when active should result in Control Room officers initiating the Fault, Incident, Emergency Response processes if they are not already underway. Albany Post ATCO Gas Australia conducts site re-assessments of all 3.16.1.4 Post Inspection Excavation ATCO Gas Australia excavation activities to test the integrity (Albany LPG Network) Site Re- of the surrounding Albany Network by surveying the area to assessment determine if any leaks have developed as a result of those activities. Excavation site re-assessments nominally take place approximately 4 weeks after excavation. Asset Asset management system monitoring, review and planning Network Maintenance 3.8.1 Asset Replacement for the planned end of life replacement of pipelines, mains, Strategy (AST Management Planning and Upgrade services, metering and pressure regulating facilities, or ST00002) and Network and 3.16.3 Asset Strategy upgrading the design or construction of existing assets to Asset Replacement Replacement assure they meet the requirements of current legislatively Strategy (AST prescribed editions of AS/NZS 4645 and AS 2885. ST00001) Specific ‘significant risk’ examples include the Multi- occupancy Dwelling project, Meter Compliance project, Metallic Mains Replacement project, etc.
Asset Pot holing and proving the location of underground assets Locating Underground 2.4.4 Electrical Isolation Location and the use of specialist equipment for locating underground Gas Leaks (SWI GE 3.6.4 Safe Work Procedures assets, such as electrical equipment, metallic pipes /cables Instructions (SWI) minimise the risk of impacting and breaking gas pipes, 002) electrical power cables/conduits, water and sewer pipes and 3.16.1 Leakage Surveys LPG Networks Leak and Leakage Detection telecommincations cables/conduits Survey and Detection (SWI LPG 002) Location of Underground Assets (SWI SSU 002) Bollards Bollards have been installed to protect above ground assets, Damage Prevention 2.4.9 Physical Security (Albany Plant which also provides exclusion of excavation equipment Management Guideline and Impact Protection Valve Pit) above the network at these locations. for ATCO Gas Facilities Measures (ENS GL0006) Bollards / ATCO Gas Australia as the network operator provides advice Damage Prevention 2.4.9 Physical Security Physical on a location-by-location basis in-line with the Above Ground Management Guideline and Impact Protection protection Asset Protection Guideline to install bollards to protect the for ATCO Gas Facilities Measures meter sets, selected pressure reducing facilities and isolation (ENS GL0006) valves (e.g. outside the Albany LPG Storage and PRS Facility from impacts. Capacity The pressure reduction facilities on the network provide limits Engineering Services 2.4.2 Pressure Limit (HPR) to the downstream flow. Design Guideline Regulation and HPRs typically limit flow to a 50mm diameter chocked flow at Regulator Sets (ENS Overpressure Protection supply pressure. PR0015)
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Title Description Documents SC Ref
Cathodic High pressure steel pipelines and City High Pressure mains Engineering Services 2.4.3 Galvanic Anode Protection have cathodic protection installed as a secondary protection Design Guideline Cathodic Protection against corrosion. Pipelines (ENS 3.8.3 Operations and Having the appropriate cathodic protection is dependent PR0019) Maintenance upon the specifications and design guidelines; correct Management installation; and ongoing monitoring.
Protective High pressure steel pipelines, regulating and metering Engineering Services 2.4.3.2 Protective Coating facilities have protective coatings installed to prevent Design Guideline Coatings external corrosion. Pipelines (ENS Having the appropriate protective coating is dependent upon PR0019) the specifications and design guidelines; correct installation; Protective Wrapping and ongoing monitoring. Protective coatings include painting, Requirements (SWI ST galvanising, wrapping with approved coating systems 013)[271] Coatings and Refurbishment and Repairs (ENS PR0022) Common Inspections of Common Trench (sub-division construction) of Engineering Services 2.4.9 Physical Security Trench mains and services are implemented to verify that gas mains Design Guideline and Impact Protection inspections (up to MAOP 350kPa) are separated from water mains by Pipelines (ENS Measures for separation distances in accordance with AS/NZS 4645 and the PR0019) and Common 3.9.2.1 Service Provider referenced documents. Trench Gas Safety Requirements Infrastructure (SWI CO 028). Concrete Concrete casings and slabbing have been installed in GNIS ‘Gas Pipe 2.4.10.2 Buried Casing response to various threat assessments. Casing’ object Concrete Slabs and Concrete Encasement
Continuity Practice of using a continuity bond in accordance with SWIs Continuity Bond (SWI 3.17.1 'Step’ and bond prior to contacting metallic pipes or facilities that may not be TE 002) ‘Touch' Potentials earthed which provides a shock potential.
DBYD Dial Before You Dig (DBYD) comprises multiple activities Dial Before You Dig 3.11.2 Dial Before You that are dependent upon an initial request for information System (CCT WI002) Dig from the public via the one-call system; accessible to the public via phone (1100), web (www.1100.com.au) or mobile applications (currently there is an iOS application). For ATCO Gas Australia the DBYD process is used to inform public of where gas assets are and what approach to take when they intend to undertake work; and a request from ATCO Gas Australia for more information for proponents for works around high pressure assets. DBYD utilises GNIS to maintain the asset record, which is regularly supplied to the 1100 one-call service; and, AIRS which prepares automated response per transaction between the one-call service and ATCO Gas Australia. DBYD (HP Where HP assets are included in the response to a DBYD Notification of All Works 3.11.2 Dial Before You Notification) request ATCO Gas Australia requests more information for around High Pressure Dig proponents for works around high pressure assets. Gas Pipelines (NCN This is dependent on the DBYD control being functional. WI008)
Depth of Depth of cover has been established within ATCO Gas Pipeline Installation 2.4.10.1 Depth of Cover Cover Australia to meet or exceed the minimum requirements of the Depth of Cover (ENS applicable standards. This minimises the potential for third WI023)[245] parties digging above the mains and services from striking Common Trench Gas ATCO Gas Australia assets. Infrastructure (SWI CO Maintaining depth of cover requires specifications for depth 028) of cover being maintained by Engineering Services and Installing a Plastic Gas contractors and ATCO Gas Australia personnel installing Main (SWI CO 020) pipe to the depth of cover requirements as per SMS Section (contract requirements). Installing a Plastic Gas Service (SWI CO 002)
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Title Description Documents SC Ref
Earth Mat Use of Earth Mats has been established where the risk of Earth Mat (SWI TE 2.4.4.2 Induced Voltage shock from faults on nearby power utilities could not be 015) mitigated through other measures. This was determined and Pipeline Earthing during the introduction of Earth Mats through MOC 2013-01. 3.17.1 'Step’ and ‘Touch' Potentials
Engineering Engineering design guidelines, or procedures coversing Refer to description 3.8.2 Design Design assets defined in the following referenced documents: Construction and Guideline Engineering Services Design Guideline Multi-storey (ENS GL0002)[269] Commissioning Engineering Services Design Guideline High-rise (ENS GL0012)[270] Meter Set Design and Selection (ENS PR0002) Engineering Services Design Guideline Regulators Sets (ENS PR0015) Engineering Services Design Guideline Valves (ENS PR0018) Engineering Services Design Guideline Pipelines (ENS PR0019) Engineering Engineering Enquiries covers third party activities that have Managing Engineering 3.17.2 Third Party Enquiry (HV been referred to Engineering Services due to the potential to Services Enquiries Electrical Asset Review Works Near impact the network which cannot be managed through (ENS WI009) HP Assets) normal operational practices. High Voltage works near high pressure steel assets can be referred from either HP Notification or through the power network operator’s practices of contacting Engineering Services directly. HV Works are managed through the enquiry process, although specifically the practice is to seek assessment and mitigation as per AS/NZS 4853 Electrical hazards on metallic pipelines.
Faults, Faults, incidents, emergency response describes the levels Emergency Response 3.15 Incident and Incidents and of event that require reactive response. The process can be Management Plan Emergency Emergency initiated through various mechanisms, but once activated (TCO PL00001) Management Response initially involves the Control Room communicating with typically a Customer Service Officer to determine the extent of the situation and then escalating in line with the Emergency Management Plan to bring in the appropriate level of resources and oversight. This is done by establishing the incident. Emergency and crisis management teams as required. Fault Albany Network provides isolation valves immediately N/A 2.4.1 GDS Isolation Response outside the Albany LPG Storage Facility and PRS013 3.15.2 GDS Isolation (Isolate, Facility, the “town centre” and some other segments of the Albany network to provide for quicker isolation than by squeeze off Isolation or Rogan Valves) Fencing ATCO Gas Australia as the network operator provides Damage Prevention 2.4.9 Physical Security (meter sets) advice on a location-by-location basis in-line with the Above Management Guideline and Impact Protection Ground Asset Protection Guideline to install fencing around for ATCO Gas Facilities Measures metersets to minimise accidental interference by third parties (ENS GL0006) and protection from impacts. The practices differ from facility types and this noted by facility type in brackets. Gas Gas transported has extremely low levels of entrained water, Network Gas Quality 3.18.1 Gas Quality Specification low sulphur and maximum specifid levels for carbon dioxide (TCO PR0011) Specifications (dry gas; low minimising corrosion risk. Minimums for gas quality are sulphur) established through regulation.
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Title Description Documents SC Ref
HP Locator ATCO Gas Australia requests works within 15 m of high Notification of All Works 3.11.3 HP Pipeline pressure pipelines to utilise a High Pressure Locator (HP around High Pressure Location and Locator) to identify the high pressure pipeline before works Gas Pipelines (NCN Engineering are undertaken. This request is made when either WI008) Assessment processing a DBYD request where high pressure pipelines are in the location of interest or when ATCO Gas Australia is contacted by third parties responding to the danger signs. HP Locators are accredited by ATCO Gas Australia based on successful completion of a training program. This control is dependent upon the third party responding and implementing requests by ATCO Gas Australia, the accreditation process for HP Locators; and the DBYD and Danger Signage being implemented properly. Regulating Regulating facility enclosure and include above-gound Engineering Services 2.4.9 Physical Security Facilities in enclosures referred to as cabinets, provide a protective Design Guideline and Impact Protection Enclosure measure from third party interference and impact; as well as Regulator Sets (ENS Measures a mitigative measure post leak by reducing the potential for PR0015) an ignition source to be nearby and reduce the momentum of any release before finding an ignition source reducing the intensity of a potential fire. Insulation Electrical separation of metallic assets into sections using Engineering Services 2.4.4.1 Insulating Joints, joints, insulation joints, gaskets and surge diverters Design Guideline Gaskets and Surge gaskets and Pipelines (ENS Diverters surge PR0019) diverters Leak Survey Leak Survey is conducted regularly depending on the Asset Class Plan – 3.16.1 Leakage Surveys location, for most of the GDS it is once per 5 years, to Pipelines, Main and and Leakage Detection identify leaks. This would initiate the Faults, Incident, and Services (AST Emergency Response process. PL00009) Leak Survey Motorcycle (SWI MA 001) Leak Survey Leak Survey in Albany in different to that for the Natural Gas LPG Networks Leak 3.16.1 Leakage Surveys (Albany) network. Leak Survey includes a yearly bar-hole survey of Survey and Leak and Leakage Detection mains, quarterly survey at surface via motorbike, post works Detection (SWI LPG survey and mains and meter position. 002) Leak Survey Leak Survey is conducted for high risk locations each year to Natural Gas Networks 3.16.1 Leakage Surveys (High Risk identify leaks. This would initiate the Faults, Incident, and Leak Survey and Leak and Leakage Detection Locations) Emergency Response process. Detection (SWI MA 008) Landowner This control is a process to interact with third parties who Landowner Occupier 3.11.6 Land Owners / Occupier own / occupy land which is traversed by high pressure Liaison Procedure Occupier Liaison Liaison pipelines. The landowner occupier liaison process informs (TCO PR0009) landowners / occupiers methods of recognising threats to the pipeline.
Marker Tape Marker Tape, where present, provides a warning for those Common Trenching 2.4.7.1 Danger Marker excavating above pipes of the GDS. It is typically installed Materials Catalogue Tape 300mm above the pipe. (NCN GL0005)[248] The GDS does not have complete coverage with marker Gas Main Marker Tape tape due to introduction of a requirement for marker tape (ENS TS027) after the inception of the GDS; and, construction methods
not allowing for the installation of marker tape. Marker tape installation is currently dependent upon where Mains and Services Laying contractors, Pipeline contractors and ATCO Gas Australia personnel installing pipe by trench are required to install marker tape in line with various procedures.
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Title Description Documents SC Ref
Material Material selection is the practice of determining the Materials Management 3.9.1.2 Materials and Selection appropriate material for the class, or sub-class, of asset. For Process (ENS PR0029) Equipment pipe and fittings on the plastic network these decisions are Common Trenching made business wide, through the Management of Change Materials Catalogue process and documented in Technical Specifications for (NCN GL0005) material approval, Safe Work Practices and Common Trench Materials Catalogue and Engineering Design Guidelines. For high pressure steel network and facilities there is the potential for engineering judgment from installation to installation and the approved materials are documented in Engineering Design Guidelines and project specific Project Management Plans with line pipe and limited fittings documented in Technical Specifications. Meter Box ATCO Gas Australia as the network operator has provided Meter Boxes for AL8-18 2.4.9 Physical Security advice through the Technical Specification and Meter Box Gas Meters (ENS and Impact Protection Placement Guide for protection measures for meter that are TS001) Measures deemed sufficient for the installation of meters. Gas Meter Box Location Handbook; For gas meter sizes; AL8 to AL 18 (NCN RF08) Meter ATCO Gas Australia may assess as fit for purpose an Gas Meter Box 2.4.9 Physical Security enclosure enclosed meter box with ventilation to open air. Public facing Location Handbook; and Impact Protection venting advice is provided in the Meter Location Guide and For gas meter sizes; Measures assessment through ATCO Gas Australia Construction AL8 to AL 18 (NCN Department. RF08) Network Isolation of a portion of the network can be achieved by SWI FS Series 2.4.1 GDS Isolation Isolation isolation valves or squeeze-off (if PE or uPVC pipe). 3.15.2 GDS Isolation Odorant and Natural Gas and LP Gas reticulated within the GDS in their Network Gas Quality 3.18 Gas Quality and Gas Quality natural state are odourless and colourless gases. (TCO PR0011) Characteristics Prior to reticulation within the GDS, Natural Gas and LP Gas Call Centre Work are odorised with chemicals (typically organic sulphur Instruction (CCT containing chemicals referred to as odorants) that impart a WI001) distinction and unpleasant smell to enable people with a normal sense of smell to detect the presence of leaking gas at low prescribed non-hazardous concentrations (20% of LEL). With respect to the Natural Gas network, odorant is added into the gas by the upstream gas transmission operators, with the exception of the Kalgoorlie network, where ATCO Gas Australia owns and operates the odorant injection facility within PRS020. With respect to the LP Gas, the LPG producers odorise the gas prior to road transportation to the Albany LPG Storage Facility. ATCO Gas Australia Gas Quality monitoring, monitors the quality of the reticulated gas to assure its compliance with prescribed specifications, including the odorant specifications.
Pavement Within the City of Perth there are weep holes as part of the Typical Installation 3.16.4 Ventilation weep hole pavement specification for the city Precautionary Gas Vent (P4-900-1434- 01A)[249] Permit to The Permit to Work System includes a Verbal Notification; Permit to Work System 3.5.14 Work under Work System Minor Work Permit for specified work activities; Major Work (TCO PR0007) Permit to Work System Permit for no routine work not covered by an authorised Network Control Permit 3.6.2 Permit to Work standard procedure; Deep Excavation (excavation greater (TCO PR 0007 WI004) System than 1.5m); Hot Work and Confined Space entry Deep Excavation (TCO PR0007 WI002) Control of Hot Work (TCO PR0007 WI003)
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Title Description Documents SC Ref Confined Space Entry Permit (TCO PR0007 WI001)
Personal Protective equipment and clothing design to prevent or Specified within SWIs 3.6.4 Safe Work Protective minimise the risk of harm from impact, airborne dust and Instructions (SWI) Equipment small projectiles, heat, excessive solar rays (sun), excessive and Personal (PPE) noise, etc Protective Equipment (HSE PR0004 WI001)[268] Pipeline Pipeline Marker Signs are installed above pipelines with Engineering Services 2.4.8 Pipeline Marker Marker Signs MAOP of 500kPa and greater; provide a warning to third Design Guideline Signs parties at the location of buried ATCO Gas Australia assets Pipelines (ENS 3.11.1 Pipeline Marker so that the third party knows to take actions to identify the PR0019) pipe before excavation. In addition to High pressure Gas Marker Signs pipelines, Pipeline Marker Signs have also been installed in (ENS TS023) critical locations of the LPG network as defined by the Albany LPG Network Formal Safety Assessment (TCO RP 0199).
Pipeline High pressure pipelines are patrolled by Pipeline Asset Class Plan – 3.11.4 Pipeline Patrol Patrol Maintenance to enable ATCO Gas Australia to monitor works Pipelines, Main and nearby that may impact the pipeline, maintain legibility and Services (AST condition of Pipeline marker Signs, monitor third party activity PL00009) encroaching on the high pressure network, maintain Pipeline Patrol (SWI ST permanent physical access to the high pressure network, 001) monitor changes in the natural site environment; and if present, detect a “smell of gas”. The systems in place that need to operate for pipeline patrols to occur are Asset Services determining frequency of patrols in the ACP, Asset Service / Planning establishing ERP maintenance notification in line with the ACP and Planning enter records into ERP post pipeline Patrol; and the training and procedures provided to the Pipeline Patrol personnel.
Planned Planned replacement of the meter may identify leak and SWI MRA 009 Gas 3.16.3 Asset Replacement replace previously installed incompatible materials. Meter Change[250] (meter; Replacement inspection)
PRS Design PRS designed to the design guideline which for Albany Engineering Services 2.4.2 Pressure (PRS013) incorporates active monitor regulators, pressure relief valves Design Guideline and OPSO. Regulator Sets (ENS Regulation and PR0015) Overpressure Protection
Pot hole Pot holing ahead of excavation to identify underground Location of 3.12 ATCO Gas cables anticipated based on the DBYD drawings. Underground Assets (SWI SSU 002) Australia Interaction with Third Parties
Pressure PRVs on the downstream side of pressure reduction Engineering Services 2.4.2.2 Gas Pressure Relief Valves facilities; where present, provides at least partial pressure Design Guideline relief. Regulator Sets (ENS Control and Safety PR0015) Devices
Preventative Pressure reduction facilities across the GDS undergo Asset Class Plans – 3.8.3 Operations and Maintenance preventative maintenance to check that they are working Pressure Regulating properly and take action required to correct defects. Facilities (AST Maintenance The scope of what receives maintenance, the maintenance PL00012) Management tasks and the period between tasks is covered in the ACP and the tasks are typically allocated as work orders through ERP.
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Title Description Documents SC Ref
Preventative Pressure reduction facilities across the GDS undergo Asset Class Plans – 3.16.1.1 Leak Detection Maintenance preventative maintenance to check that they are working Pressure Regulating (leak check) properly; the first stage of this maintenance is checking for Facilities (AST and Leak Prevention leaks. PL00012) Controls The scope of what receives maintenance, the maintenance Site Setup (SWI SSU tasks and the period between tasks is covered in the ACP 001) and the tasks are typically allocated as work orders through
ERP. Maintenance work conducted to Safe Work Instructions and SWIs for work invoke the site setup SWI which includes checking for leaks.
PM (Albany Inspection and maintenance activities are undertaken at Operation of Albany 3.8.3 Operations and Plant) regular intervals at Albany Plant. The inspection activities LPG Storage Facility that should identify gas escapes. (Daily, Weekly, Monthly Maintenance and Annual Checks Management The physical controls at Albany Plant are maintained at [251] appropriate intervals. (SWI LPG 006)
SWI: Proving SWI MA005 provides process for determining the status of Proving the Status of 3.8.5 Asset Abandoned abandoned mains with the risk of ATCO Gas Australia Abandoned Gas Mains Decommissioning/Retire Mains personnel being exposed to a line service being minimised (SWI MA 005) ment through a services of checks based on the potential for the pipe carrying gas, water or being a conduit for electrical cables.
Fencing Fencing is installed at PRS sites to keep the public away Damage Prevention 2.4.9 Physical Security (PRS) from the assets and minimise the potential for third party Management Guideline activities from impacting onto the PRS. for ATCO Gas Facilities and Impact Protection (ENS GL0006) Measures Quality Persons authorised to procure materials and component may Procurement Policy Control nominate ‘quality standards’; typically an ATCO Gas (COM PO00001) 3.9.1.1 Supply Chain, (Procurement Australia Technical Specific or recognised standard. Procurement and to Recognised standards are those cited in the governing Quality Control Specification) network standard for the material or component being ordered. Technical Specifications include the requirements, if any, on the supplier for testing. Meter Meter reading is conducted quarterly by a contractor and Contract in place with 3.16.1.1 Leak Detection Reading (leak their personnel are required to report gas leaks if found. This meter readers. and Leak Prevention check) would initiate the Faults, Incident, and Emergency Response Controls process. Replacement Components of the GDS undergo replacement at defined Asset Management 3.16.3 Asset Plan intervals. During the replacement there are checks for the Plan 2016-2010 (AST Replacement soundness of the pipe and location the component is being PL00003) attached to. The scope of what is replaced and the period between replacements is covered in the ACP and the tasks are typically allocated as work orders through ERP and maybe implemented as projects. Road Much of the GDS is located in road reserves and there is an Utility Providers Code 2.4.9 Physical Security Reserve agreement between utility providers on the location of utilities of Practice for Western and Impact Protection (Separation to certain alignments. Australia (Dial Before Measures of Utilities) You Dig WA Ltd) Slabbing Concrete slabbing and casings have been installed in GNIS ‘Gas Pipe 2.4.10.2 Buried response to various threat assessments. Casing’ object Concrete Slabs and Concrete Encasement
SWI: SWIs covering services installation as part of installation Installing a Plastic Gas 3.6.4 Safe Work Services requirements; and the associated SWIs for site set-up and Service (SWI CO 002) Instructions (SWI) commissioning.
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Title Description Documents SC Ref
SWI: Procedures for inserting new Services into old, for example Installing a Plastic Gas 3.6.4 Safe Work Services Galvanised Iron Services requires the installation of an Service (SWI CO 002); Instructions (SWI) (Sealing annulus sealing compound to prevent the old service pipe Relay Service (SWI CO annulus) from becoming a conduit, or path for leak tracking to a 009)[259] building. SWI: Water in Water in Main (SWI MA 004) provides structured response to Water in the Main (SWI 3.15 Incident and the Main water in the mains. Could be considered a specific practice MA 004)[252] Emergency for the broader incident response control. Management
Systems ATCO Gas Australia utilises various systems for monitoring Flow Computing and 2.4.6 System Monitoring Monitoring (either via monitored alarms, or remotely logging into the Telemetry (NCO device) various GDS operational parameters, such as PR0001) & Control (Telemetry) pressure, flow, temperature (limited), CP rectifier transformer Room Response to units (RTUs), OPSOs and the Kalgoorlie odorant injection Network Monitoring system. Devices (CTR PR0004) Third Party ATCO Gas Australia utilises a variety of mechanisms for Third Party Pipeline 3.11.5 Awareness, Awareness increasing awareness of hazards and the need for safety Damage Prevention Advertising and Training Programs precautions to be in place when working near ATCO Gas Manual (NCO Australia assets. These include: MA00001) - Participation by ATCO Gas Australia personnel in external committees such as Utility Providers and Services Committee and various Standards Australia committees; - Conducting Third Party Damage Prevention Awareness Sessions; - Visits by Patrollers and HP Co-ordinator to tool box meetings, project sites and daily meetings; and - Membership of the Energy Networks Association and Australian Pipelines and Gas Association (APGA) ATCO Gas Australia also target companies for repeat offences and offer them advice on the prevention of third party damage to the ATCO Gas Australia GDS. Tracer Wire Tracer Wire, where present, allows for the location of plastic Engineering Services 2.4.7.3 Tracer Wire pipe on the GDS using pipe locators. The recommended Design Guideline technic requires the initial safe location of the pipe to allow Pipelines (ENS PR for connection to be made to the tracer wire and with the use 0019) of active pipe locators the location of the plastic pipe can be Common Trench Gas determine for some distance from the known location. Infrastructure (SWI CO The GDS does not have complete coverage of tracer wire on 028) plastic pipe due to the requirement for tracer wire being introduced after the inception of the GDS. Tracer wire installation is currently dependent upon where Location of Mains and Services Laying contractors, Pipeline contractors Underground Assets and ATCO Gas Australia personnel installing pipe by trench (SWI SSU 002) are required to install marker tape in line with various procedures. Use of Tracer Wire is part of Location of Underground Assets (SWI SSU 002). Training and Employees and direct engaged contractor that work on the Training Management 3.7.3 Training & Competency ATCO Gas Australia GDS are provided with training relevant Process (TRN PR0001) Competencies to the tasks undertaken and are assessed to verify their competencies in accordance with Training Management Process (TRN PR0001) Use cable Using cable locator in line with Location of Underground Location of 3.12 ATCO Gas locator Assets (SWI SSU 002) to locate underground cables. Underground Assets Australia Interaction (SWI SSU 002) with Third Parties Volt stick Practice of using a volt stick in accordance with Volt Stick Volt Stick (SWI TE 001) 3.17.1 'Step’ and (SWI TE 001) prior to contacting metallic assets or meter ‘Touch' Potentials boxes that maybe live due to an electrical fault.
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4.4 Implementation of Alternative Means of Compliance to Provisions of AS/NZS 4645 As stated in the Safety Case Section 1, AS/NZS 4645.1 allows for alternative means of compliance to be documented and approved, where aspects of the management of the GDS are not in accordance with ‘an acceptable means of compliance’ (‘deemed to comply’) as defined within AS/NZS 4645. AS/NZS 4645.1 allows the Network Operator to define its ‘acceptable means of compliance’ by its own approved standard or specification; or approved tests and investigation that achieve the outcome of the FSA (that validates the achievement of an acceptable level of risk, or that risk is ‘intermediate’ and ALARP). FSA has identified four (4) distinct ‘deemed to comply’ deviations from the prescribed requirements of AS 4645 for the ATCO Gas Australia GDS and they are described in sections 4.4.1 to 4.4.4. Any further ‘deemed to comply’ deviations of this nature identified for the ATCO Gas Australia GDS will be similarly subjected to FSA prior to approval of alternative ‘acceptable means of compliance’.
Alternate ATCO Gas Australia GDS ‘acceptable means of compliance’ are listed in Table 4-6.
Table 4-6 Alternative Acceptable Means of Compliance to Provisions of AS/NZS 4645
ATCO Gas Australia Date Deviation AS/NZS 4645 Ref Report Conducted
Separation distances for AS/NZS 4645.3 Service Separation FSA 3/7/2015 services Clause 5.5.3 (TCO RP 0179)
Separation distances for AS/NZS 4645 Figure Meter Box Separation 16/12/2015 Meter boxes from open K1 and Figure K2 Distance FSA (TCO RP windows and electrical meter 0190) boxes
PE >DN200 AS/NZS 4645.3. Formal Safety Assessment 30/6/2016 Clause 1.1, Clause Operating PE Pipelines 3.7 Greater Than DN200 Above 600 kPa (GD RP 0860) [253].
Aligning components to AS AS/NZS 4645.1 Non-Standard Component 31/12/2016 4645 Section 4.5.1 Review - Record of Failure Mode Effects Analysis
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4.4.1 Separation distances for services 4.4.1.1 Standard Requirement Australian standard AS/NZS 4645.3 Clause 5.5.3 requires that there is at least a 250mm separation distance between a gas service and any other underground utility. 4.4.1.2 Deviation ATCO Gas Australia has had a deviated from this standard requirement through a historical practice of providing 150mm separation in safe work instructions which is in line with the Dial Before You Dig WA Ltd, Utility Providers Code of Practice for WA.
4.4.1.3 Assessment An FSA was conducted to risk assess the options of having 250mm and 150mm separation distance. Based on the risk review, it can be concluded that a separation distance of 150mm between gas services and third party underground assets is equal in risk.
4.4.2 PE >DN200 4.4.2.1 Standard Requirement AS/NZS 4645.3 Section 1.1 states that the standard does not include polyethylene (PE) pipelines greater than DN200 operating above Maximum Allowable Operating Pressure (MAOP) of 600 kPa. AS4645.1 Section 4.5 allows for deviation from AS4645.3 if there is: • (a) An appropriate Standard or specification that is approved as being suitable. • (b) Adequate safety and fitness for purpose as demonstrated by approved tests and/or 4.4.2.2 Deviation ATCO Gas Australia constructs and operates PE pipelines greater than DN200 operating at 700kPa. 4.4.2.3 Assessment An FSA was conducted to aid in the development and approval of a technical specification for pipelines with diameters greater than DN200 and operating at pressures greater than MAOP 600kPa. The technical specification ENS TS0002 UPVC and PE pipe was created and approved which includes PE pipe DN225 operating at 700kPa MAOP. The FSA found that ATCO Gas Australia significantly exceeds the construction requirements of AS 4645.3:2008 for PE Pipelines greater than DN200 operating at MAOP of more than 600 kPa in several areas: • Design for depth of cover for PE pipelines is 1200mm as opposed to 750mm required, exceeding the standards minimum requirement by 60%. • The 700 kPa PE pipelines mains are also identified as High Pressure (HP) on ATCO Gas Australia’s Dial Before You Dig (DBYD) maps requiring notification and site supervision for any excavations or construction works within 15 m in the same way as HP Steel pipelines • Pipeline marker signs are also installed at minimum 150 m intervals along the pipeline route • Weekly pipeline patrols are completed on PE pipelines with MAOP greater than 600 kPa.
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Further details found in FSA Formal Safety Assessment Operating PE Pipelines Greater Than DN200 Above 600 kPa (GD RP 0860).
4.4.3 Separation distances for Meter boxes 4.4.3.1 Standard Requirement AS/NZS 4645.1:2008 Figure K1 requires gas regulators to have at least 1m separation to openable windows and doors while Figure K2 requires at least 500mm separation between gas regulators and electrical meter boxes. 4.4.3.2 Deviation • ATCO Gas Australia allows meter boxes to be 750mm away from openable doors and windows • ATCO Gas Australia allows gas meter boxes to be directly adjacent to electrical meter boxes
4.4.3.3 Assessment ATCO Gas Australia has acknowledged that in certain situations, there is the potential for the gas regulator to vent and release gas to prevent an overpressure event. Based on the field testing and risk review, it can be concluded that for a natural gas network, the following meter box separation distances are reduced to an acceptable level: • No separation distance is required between a Gas Meter Box and Electrical Meter Box, where testing has proven that within a Combination Meter Box with sealing between the Electrical Meter and Gas Meter Box Compartment and an adequately ventilated Gas Meter Box, the risk of ignition within the Electrical Meter Box is reduced to an acceptable level. • 500mm separation distance is required between a gas meter box and ignition sources. • 750mm separation distance is required between a gas meter box and doors or windows however if a non-venting regulator or a vent line is fitted to a safe location, 250mm separation may be approved. Details of this FSA can be found in the report Meter Box Separation FSA TCO RP0190[250].
4.4.4 Non-Standard Fittings 4.4.4.1 Standard Requirement AS/NZS 4645.1 Section 4.5.1 requires materials and components to be fit for purpose which is determined by compliance to requirements of AS/NZS 4645. 4.4.4.2 Deviation. ATCO Gas Australia currently uses components on the GDS that are not approved through the requirements of AS/NZS 4645. These components include: • ENS TS012 Compression Couplings, • ENS TS055 Service Riser, • ENS TS014 Tapping Bands for uPVC Gas Pipe.
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4.4.4.3 Assessment An FMEA assessment has been conducted on each of these materials to identify the credible failure modes. The assessment found that sufficient controls are in place to ensure an acceptable risk when using these non-standard fittings. It has been concluded that these materials are fit for purpose and have had approved technical specifications for each item. Details of the FMEA can be found in the report TCO RP 0228 Non-Standard Fittings FMEA.
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5. REFERENCES [1] Economic Regulation Authority of Western Australia 2013, Gas Distribution Licence ATCO Gas Australia Pty Ltd GDL8, Version 8, 01 January 2013, Perth, viewed 25 September 2014,
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[22] Dangerous Goods Safety (Storage and Handling of Non-explosives) Regulations 2007 (WA), State Law Publisher, Perth, viewed 25 September 2014,
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[45] The American Society of Mechanical Engineers 2004, Welded and Seamless Wrought Steel Pipe, ASME B36.10M-2004, The American Society of Mechanical Engineers, New York. [46] ASTM International 2003, Standard Specification for Grey Iron Castings, A 48/A 48M – 03, ASTM International, West Conshohocken. [47] ATCO Gas Australia 2016, Asset Class Plan – Pressure Regulation Facilities, AST PL00012. [48] ATCO Gas Australia 2016, Asset Class Plan – Pipelines, Mains and Services, AST PL00009. [49] ATCO Gas Australia 2014, Assets & Systems Performance & Health Monitoring 2013, AST PR0005. [50] ATCO Gas Australia 2015, Meter Set Design & Selection, ENS PR0002. [51] ATCO Gas Australia 2014, Engineering Services Design Guideline Regulator Set including OPSO, ENS PR0015. [52] ATCO Gas Australia 2011, Flow Computing and Telemetry Equipment, NCO PR0001. [53] ATCO Gas Australia 2016, Network Maintenance Strategy, AST ST00002. [54] ATCO Gas Australia 2014, Corrosion Mitigation Systems, NCN PR0002. [55] ATCO Gas Australia 2013, Coating Refurbishment & Repair, ENS PR0022. [56] ATCO Gas Australia 2016, Asset Class Plan – Cathodic Protection Systems, AST PL00006. [57] Standards Australia/Standards New Zealand 2002, Guide to the protection of structural steel against atmospheric corrosion by use of protective coatings, AS/NZS 2312:2002, Standards Australia, Sydney. [58] ATCO Gas Australia 2014, Project Management Plan, ENS PL0002. [59] Standards Australia/Standards New Zealand 2000, Electrical hazards on metallic pipelines, AS/NZS 4853:2000, Standards Australia, Sydney. [60] ATCO Gas Australia 2015, Ground Penetration Equipment, ENS TS040. [61] ATCO Gas Australia 2016, Locating Underground Gas Leaks, SWI GE 002. [62] ATCO Gas Australia 2015, Continuity Bond, SWI TE 002. [63] Standards Australia/Standards New Zealand 2005, Electrical equipment for explosive gas atmospheres-Selection, installation and maintenance Part 1: General requirements, AS/NZS 2381:2005, Standards Australia, Sydney. [64] ATCO Gas Australia 2015, Volt Stick, SWI TE 001. [65] ATCO Gas Australia 2015, Earth Mat, SWI TE 015. [66] Standards Australia/Standards New Zealand 2009, Explosive atmospheres Part 10.1: Classification of areas-Explosive gas atmospheres (IEC 60079-10-1, Ed.1.0(2008) MOD), AS/NZS 60079.10.1:2009, Standards Australia, Sydney. [67] ATCO Gas Australia 2014, Control Room Response to Network Monitoring Devices, CTR PR0004. [68] ATCO Gas Australia 2016, Asset Class Plan – Telemetry Equipment, AST PL00013. [69] Dial Before You Dig WA Ltd 2016, Utility Providers Code of Practice For Western Australia, Utility Providers Services Committee, Perth,
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[76] ATCO Gas Australia 2015, Gas Marker Signs, ENS TS023. [77] Standards Australia 1994, Safety signs for the occupational environment, AS 1319-1994, Standards Australia, Sydney. [78] ATCO Gas Australia 2017, Meter Boxes for AL8-18 Gas Meters, ENS TS001 [79] ATCO Gas Australia 2016, Gas Meter Box Location Handbook; For gas meter sizes; AL8 to AL 18, NCN RF08 [80] ATCO Gas Australia 2014, Damage Prevention Management Guideline for ATCO Gas Facilities, ENS GL0006. [81] ATCO Gas Australia 2014, Pipeline Installation Depth of Cover, ENS WI 023. [82] ATCO Gas Australia 2016, Installing a Plastic Gas Main, SWI CO 020 [83] ATCO Gas Australia 2011, Installing a Plastic Gas Service, SWI CO 002 [84] ATCO Gas Australia 2014, Concrete Protection for Gas Pipelines, ENS PR0005. [85] ATCO Gas Australia 2015, Network Gas Quality, TCO PR0011 [86] ATCO Gas Australia 2015, Gas Analysis and Reporting, NCO PR0010 [87] ATCO Gas Australia 2015, Collection of Natural Gas and LPG Samples, SWI AN 001. [88] ATCO Gas Australia 2014, Odorant Analysis Using Gastec Tubes, SWI AN 002. [89] ATCO Gas Australia 2014, Odorant Analysis Using Odor Handy Plus, SWI AN 003 [90] ATCO Gas Australia 2014, ATCO Gas Australia Gas Quality Update, NCO PR0015 [91] Gas Supply (Gas Quality Specifications) Regulations 2010
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[113] Standards Australia 2003, Hazard and operability studies (HAZOP) studies)-Application guide, AS IEC 61882-2017, Standards Australia, Sydney. [114] ATCO Gas Australia 2015, Chemical Management Guide, HSE GL0002 [115] ATCO Gas Australia 2015, Pre-task Hazard Assessment Process, HSE PR0025 WI001. [116] ATCO Gas Australia 2013, Job Risk Assessment, HSE PR0025 WI001 RF02. [117] ATCO Gas Australia 2011, Project Risk Management, ENS PR 0001 WI001 [118] ATCO Gas Australia 2016, Network Control Permit, TCO PR 0007 WI004 [119] ATCO Gas Australia 2014, Register of Work Permits and Verbal Notifications, TCO PR0007 WI004 RF03. [120] ATCO Gas Australia 2017, Minor Work Permit Form, TCO PR0007 WI004 RF01. [121] ATCO Gas Australia 2016, Major Work Permit Form, TCO PR0007 WI004 RF02. [122] ATCO Gas Australia 2017, Confined Space Register, TCO PR0007 WI001 RG01. [123] ATCO Gas Australia 2016, Confined Space Entry Permit, TCO PR0007 WI001 RF01. [124] ATCO Gas Australia 2016, Confined Space Initial Assessment, TCO PR0007 WI001 RF02. [125] ATCO Gas Australia 2016, Deep Excavation, TCO PR0007 WI002 [126] ATCO Gas Australia 2017, Control of Hot Work, TCO PR0007 WI003 [127] ATCO Gas Australia 2016, Safe Work Instruction Shoring of Excavations, SWI EX 003. [128] ATCO Gas Australia 2015, Recruitment & Selection, HRS PR0004. [129] ATCO Australia 2016, Respect in the Workplace Policy, AA-HR-PO-027. [130] ATCO Gas Australia 2015, Personal Information & Privacy, HRS PR0006. [131] ATCO Gas Australia 2017, Training Management Process, TRN PR0001. [132] ATCO Gas Australia 2015, Project Management Manual, PMM MA00001 [133] Standards Australia/Standards New Zealand 2014, The storage and handling of LP Gas, AS/NZS 1596:2014, Standards Australia, Sydney. [134] Standards Australia/Standards New Zealand 1998, Buried flexible pipelines Part 1: Structural design, AS/NZS 2566.1:1998, Standards Australia, Sydney. [135] Standards Australia/Standards New Zealand 2002, Buried flexible pipelines Part 2: Installation, AS/NZS 2566.2:2002, Standards Australia, Sydney. [136] Standards Australia 2008, Pipelines-Gas and liquid petroleum Part 0: General Requirements, AS 2885.0-2008, Standards Australia, Sydney. [137] Standards Australia 2007, Pipelines-Gas and liquid petroleum Part 2: Welding, AS 2885.2- 2007, Standards Australia, Sydney. [138] Standards Australia/Standards New Zealand 2002, Pipelines-Gas and liquid petroleum Part 5: Field pressure testing, AS/NZS 2885.5:2002, Standards Australia, Sydney. [139] Standards Australia/Standards New Zealand 2007, Electrical installations (known as the Australian/ New Zealand Wiring Rules), AS/NZS 3000:2007,Standards Australia, Sydney. [140] Standards Australia 2006, Pressure piping, AS/NZS 4041-2006, Standards Australia, Sydney. [141] Standards Australia/Standards New Zealand 2006, Hot-dip galvanized (zinc) coatings on fabricated ferrous articles, AS/NZS 4680:2006, Standards Australia, Sydney. [142] Standards Australia 2000, Installation of underground utility services and pipelines within railway boundaries, AS 4799:2000, Standards Australia, Sydney. [143] American Petroleum Institute, API 5L, Specification For Line Pipe, 45th Edition December 2012 [144] Standards Australia/Standards New Zealand 2008, Fittings for polyethylene (PE) pipes for pressure applications, AS/NZS 4129:2008, Standards Australia, Sydney. [145] Standards Australia/Standards New Zealand 2010, Polyethylene (PE) compounds for pressure pipes and fittings, AS/NZS 4131:2010, Standards Australia, Sydney. [146] ATCO Gas Australia 2017, Network Planning Design Standard, AST PL00016. [147] ATCO Gas Australia 2016, Work Site and General Inspections, TCO PR0001.
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[148] ATCO Gas Australia 2015, Asset Management Plan – Albany Network, AST PL00004. [149] Isograph 2009, Availability Workbench 2009 User Guide, Isograph Limited, Los Angeles. [150] ATCO Gas Australia 2016, Safe Work Instruction Decommissioning Mains and Commercial Services, SWI MA 003. [151] ATCO Gas Australia 2015, Asset Retirement, ENS GL0009. [152] ATCO Gas Australia 2016, Procurement Policy, COM PO00001. [153] ATCO Gas Australia 2012, Contractor Engagement, COM PR0003. [154] ATCO Gas Australia 2011, Contractor Application (Type A), COM PR0003 RF02. [155] ATCO Gas Australia 2011, Periodic Contractor Evaluation, COM PR0003 RF07. [156] ATCO Gas Australia 2012, Probity Guidelines, COM PO00001 GL0002. [157] ATCO Gas Australia 2012, Form Template Probity Checklist, COM PO00001 GL0002 RF01. [158] ATCO Gas Australia 2016, Network Infrastructure Business Case (Growth and Maintenance CAPEX) Template, FIN PR0003. [159] ATCO Gas Australia 2012, Capital Expenditure Appropriation Request Template, FIN PR0004. [160] ATCO Gas Australia 2012, Inspection and Test Plan, ENS PR00001 RF02 [161] Intergovernmental Committee on Surveying & Mapping 2009, Geocentric Datum of Australia Technical Manual, Version 2.3(1), Intergovernmental Committee on Surveying & Mapping, Canberra, viewed 26 September 2014,
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[186] ATCO Gas Australia 2016, Pipeline Schematic; PL Schematic – P4-900-0332-03 – Rockingham Region [187] ATCO Gas Australia 2016, Pipeline Schematic; PL Schematic – P4-900-0332-04 – Bunbury Region [188] ATCO Gas Australia 2016, Pipeline Schematic; PL Schematic – P4-900-0332-05 – Metro Northern Region [189] ATCO Gas Australia 2016, Pipeline Schematic; PL Schematic – P4-900-0332-06 – Geraldton Region [190] OSD Pipelines Pty Ltd 2010, WAGN Geraldton Lateral – HP102 Isolation Plan for WAGN, 82802-DOC-002. [191] ATCO Gas Australia 2014, HP 125 Pipeline Isolation Plan, TCO PL00014. [192] ATCO Gas Australia 2013, HP134 Pipeline Isolation Plan, TCO RP 0125. [193] ATCO Gas Australia 2013, HP132 Pipeline Isolation Plan, TCO RP 0124. [194] ATCO Gas Australia 2013, HP131 Pipeline Isolation Plan, TCO RP 0123. [195] ATCO Gas Australia 2013, HP128 Pipeline Isolation Plan, TCO RP 0122. [196] ATCO Gas Australia 2013, HP127 Pipeline Isolation Plan, TCO RP 0121. [197] ATCO Gas Australia 2015, Mandurah Gas Lateral (HP120 & HP129) Pipeline Isolation Plan, TCO PL 00014. [198] ATCO Gas Australia 2017, Safe Work Instruction Use of FERU, SWI FERU 001. [199] ATCO Gas Australia 2016, Engineering Services Design Guideline Pipelines, ENS PR 0019. [200] ATCO Gas Australia 2014, Engineering Services Design Guideline Valves, ENS PR0018. [201] ATCO Gas Australia 2012, CBD Emergency Isolation, TCO PL00001 WI004. [202] ATCO Gas Australia 2016, Repair Mains and Services, SWI RT 001. [203] ATCO Gas Australia 2017, Operating Rogan Equipment, SWI FS 001. [204] ATCO Gas Australia 2015, Rogan Single Bag Isolation, SWI FS 002 [205] ATCO Gas Australia 2014, Clements Plugging Tool, SWI FS 003 [206] ATCO Gas Australia 2015, Service Riser Plugging Tool, SWI FS 004 [207] ATCO Gas Australia 2016, Operate Manual Squeeze Off - Service Isolation Only, SWI FS 005. [208] ATCO Gas Australia 2016, Service Plugging Tool, SWI FS 006. [209] ATCO Gas Australia 2014, Operation of a Cutter Tee, SWI FS 007 [210] ATCO Gas Australia 2017, Modified Tapping Band Replacement Tool, SWI FS 008. [211] ATCO Gas Australia 2016, Operate Squeeze Off - Monitor and Bypass, SWI FS 009. [212] ATCO Gas Australia 2017, Service Valve Replacement Tool, SWI FS 010 [213] ATCO Gas Australia 2016, Live Gas Service Isolator Tool, SWI FS 011 [214] ATCO Gas Australia 2011, Work Instruction After Hours Call Out Roster, TCO PL00001 WI003. [215] ATCO Gas Australia 2015, Emergency & Operational Contacts, TCO PL00001 RF07 [216] Department of Finance Public Utilities Office of Western Australia 2013, State Emergency Management Plan for Gas Supply Disruption [Westplan – Gas Supply Disruption], June, Perth, viewed 25 September 2014,
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[223] ATCO Gas Australia 2015, Leak Survey Motorcycle, SWI MA 001 [224] ATCO Gas Australia 2016, Natural Gas Networks Leak Survey and Leak Detection, SWI MA 008 [225] ATCO Gas Australia 2016, Multi-Storey Buildings Leak Survey and Asset inspection, SWI MA 009 [226] ATCO Gas Australia 2015, LPG Networks Leak Survey and Detection, SWI LPG 002. [227] ATCO Gas Australia 2017, Albany LPG Network Formal Safety Assessment, TCO RP 0199 [228] ATCO Gas Australia 2016, Attending Gas Escapes, SWI GE 001. [229] ATCO Gas Australia 2016, Asset Management Plan 2016-2020, AST PL00003 [230] Standards Australia 2004, Gas Installations, AS 5601-2004, Standards Australia, Sydney. [231] ATCO Gas Australia 2015, Ventilation Guidelines for ATCO Gas Australia Facilities, ENS GL0007. [232] ATCO Gas Australia 2016, Lightning Safety, TCO GL0003 [233] ATCO Gas Australia 2015, Proving the Status of Abandoned Gas Mains, SWI MA 005. [234] ATCO Gas Australia 2015, Managing Engineering Services Enquiries, ENS WI009 [235] ATCO Gas Australia 2014, Master Obligation Register, REG RG001. [236] ATCO Gas Australia 2016, Technical Compliance Auditing, TCO PR0005. [237] ATCO Gas Australia 2016, Site Inspection - Disconnect Gas Service at Main, TCO PR0001 RF13. [238] ATCO Gas Australia 2016, Multi Occupancy Dwellings Project, 1521-2016-GCA1-SM-023 [239] ATCO Gas Australia 2017, Non-Standard Fittings FMEA, TCO RP 0228. [240] ATCO Gas Australia 2014, Gas Distribution Network Formal Safety Assessment, TCO RP 0008. [241] ATCO Gas Australia 2013, Albany Network Replacement Project, 1521-2013-GCA1-SM-040 [242] ATCO Gas Australia 2015, Facility Upgrade: Step Touch Mitigation Project, 1521-2015-GCA1- SM-012 [243] ATCO Gas Australia 2016, Replacement: M6WA Meters with Plugs Project, 1521-2016-GCA1- SM-003 [244] ATCO Gas Australia 2017, Gas Distribution Network FSA, TCO RP 0194 [245] ATCO Gas Australia 2014, Pipeline Installation Depth of Cover, ENS WI023 [246] ATCO Gas Australia 2013, End of Life Replacement – Metallic Mains, 1521-2016-GCA1-SM- 004 [247] ATCO Gas Australia 2013, Albany Galvanised Replacement Project, 1521-2013-GCA1-SM- 024 [248] ATCO Gas Australia 2013, Common Trenching Materials Catalogue, NCN GL0005 [249] ATCO Gas Australia 2014, Typical Installation Precautionary Gas Vent , P4-900-1434-01A. [250] ATCO Gas Australia 2015, Gas Meter Change, SWI MRA 009 [251] ATCO Gas Australia 2016, Operation of Albany LPG Storage Facility (Daily, Weekly, Monthly and Annual Checks, SWI LPG 006 [252] ATCO Gas Australia 2011, Water in the Main, SWI MA 004 [253] WA Gas Networks 2011, Formal Safety Assessment Operating PE Pipelines Greater Than DN200 Above 600 kPa, GD RP 0860. [254] ATCO Gas Australia 2017, Meter Box Separation FSA, TCO RP0190 [255] ATCO Gas Australia 2011, Flow Computing and Telemetry Equipment, NCO PR0001 [256] ATCO Gas Australia 2013, Multistorey Building Project, 1521-2013-GCA1-SM-023 [257] ATCO Gas Australia 2016, Waterbank Development Project, 1521-2016-GCA1-NM-001 [258] ATCO Gas Australia, AS2885 Safety Management Study Reviews ATCO Gas Australia Class 300 & 600 Pipelines, TCO RP 0245 Rev 0
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[259] ATCO Gas Australia 2011, Relay Services, SWI CO 009 [260] ATCO Gas Australia 2014, Network Pressure Management of Change, NCO PR0013 [261] Standards Australia 2006, Commercial propane and commercial butane for heating purpose; AS 4670-2006, Standards Australia, Sydney [262] ATCO Gas Australia 2014, Codes and Practices (Site Workplace Specific Legislation affecting Gas Distribution, TCO PL00005 RF01 [263] ATCO Gas Australia 2017, Halt' Shut-Off Device Utilising the FERU, SWI FERU 002 [264] ATCO Gas Australia 2017, Plidco Flange+Repair-Ring Utilising the FERU, SWI FERU 003 [265] ATCO Gas Australia 2017, Plidco Split+Sleeve Utilising the FERU, SWI FERU 005 [266] ATCO Gas Australia 2017, Skinner Vented Plug Clamp Utilising The FERU, SWI FERU 006 [267] ATCO Gas Australia 2014, Squeeze-Off Steel Pipeline Utilising the FERU, SWI FERU 007 [268] ATCO Gas Australia 2014, Personal Protective Equipment, HSE PR0004 WI001 [269] ATCO Gas Australia 2014, Engineering Services Design Guideline Multistorey (ENS GL0002) [270] ATCO Gas Australia 2016, Engineering Services Design Guideline Highrise (ENS GL0012) [271] ATCO Gas Australia 2014, Protective Wrapping Requirements (SWI ST 013)
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APPENDICES
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APPENDIX 1. ATCO GAS AUSTRALIA PTY LTD ORGANISATIONAL STRUCTURE
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ATCO Australia Managing Director and COO
ATCO Gas Australia Chief Financial General Manager Corporate Services & President Officer Corporate Affairs & HR Legal – General Counsel
General Manager General Manager Assets General Manager General Manager Senior Manager General Manager Manager Supply Senior Manager Senior Legal & Operations & Engineering Innovation Construction Customer Sales and HSE Regulatory Chain Risk & Compliance Legal Counsels Business Development
Manager Procurement Governance & Manager Senior Manager Manager High Specialists & Analyst Customer Compliance Operations North Technical Services Density Solution Experience Lead
Information Manager Management Manager Asset Capital Projects Customer Sales Operations South Coordinator Services Manager Manager
Manager Network Manager Control Engineering Project Manager Services
Regional Manager Technical Manager Operations Construction Manager Compliance Programs
Manager Quality Transmission Assurance Lead Infrastructure
Document: TCO PL00005 Page 167 of 167 Revision: 6 WARNING: UNAUTHORISED ACCESS OR DEALING WITH THIS DOCUMENT IS STRICTLY PROHIBITED Issue Date: 01/12/2017