CONSTRUCTION SAFETY STUDY REPORT FOR KEEPIT DAM UPGRADE WORK PACKAGE 2 KEEPIT DAM POST TENSIONING

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1 CONSTRUCTION SAFETY STUDY REPORT FOR KEEPIT DAM UPGRADE WORK PACKAGE 2 KEEPIT DAM POST TENSIONING Incorporating Dam Safety Management Plan PREPARED BY: SRG CIVIL PTY LTD AUTHORISED BY: Andrew McFarlane Last Revised DATE: 18 th May2017 Page 1 of 86

2 TABLE OF CONTENTS 1. OUTLINE OF PROPOSED & EXISTING OPERATIONS...5 Site location in relation to surrounding land uses...5 Site Layout...5 Purpose of Proposed Operation and Major Steps...6 Existing Operations...6 Major Contractors REQUIREMENTS OF the CONSTRUCTION SAFETY STUDY STUDY METHODOLOGY HAZARDS IDENTIFIED & PROPOSED SAFEGUARDS...9 Keepit Dam Risk Register ASSESSMENT OF OPERATIONAL SAFEGUARDS SAFETY ASSURANCE CONSTRUCTION PROGRAMS Extent of Work Concrete Works Anchor Fabrication Cable Anchor Hole Drilling Cable Anchor Hole Testing Waterproofing Grouting of Cable Anchor Hole Anchor Installation Anchor Grouting Anchor stressing MANAGEMENT OF CHANGE Glossary & Abbreviation Appendix 1 - Draft Construction Programme Page 2 of 86

3 Appendix 2 - Keepit Dam Risk Register Appendix 3 - Hazardous Materials Register Appendix 4 - SRG Polices Appendix 5 - Examples of SRG Procedures Appendix 6 - Checklist Hazardous Industry Planning Advisory Paper No.7 Construction Safety Appendix 7 - Dam Safety Management Plan Page 3 of 86

4 EXECUTIVE SUMMARY Description of Proposal The proposal is Keepit Dam Upgrade Works Stage 2, Package 2 and includes strengthening the concrete gravity sections and spillway piers via post tensioning works to be referred to as Stage 2, Package 2 - Post Tensioning Works. The main works package includes installation of post tensioned cable anchors in the concrete section of the existing dam including the left abutment non-overflowing monoliths, right abutment non-overflow monoliths and spillway piers and other associated works. Purpose and Scope The purpose of this study is to identify potential hazardous incidents that may occur during the construction phase of the above proposed project. The scope of the study is based around the scope of the project and the draft construction program attached. Major Findings Major findings from the study are that the SRG procedures and processes will be sufficient to manage all safety, quality and environmental hazards as identified in this report. Major Potential Hazardous Incidents The major potential hazardous incidents that were identified by the study include but are not limited to; - Flooding; - Removal of Asbestos; - Dam Safety; - Working at Height. Page 4 of 86

1. OUTLINE OF PROPOSED & EXISTING OPERATIONS Site location in relation to surrounding land uses The site is situated on the south-western corner of Lake Keepit approximately fifty (50) kilometres

5 1. OUTLINE OF PROPOSED & EXISTING OPERATIONS Site location in relation to surrounding land uses The site is situated on the south-western corner of Lake Keepit approximately fifty (50) kilometres from Tamworth NSW. Surrounding land uses include; - Existing Keepit Dam; - State Park and associated clubs including the Sailing and Fishing Clubs; - Camping grounds and caravan park; - WaterNSW site offices and living quarters; - Private residences and farming land. Site Layout The site layout will include fabrication and storage beds, drilling and installation equipment operating on dam crest and spillways, office facilities and amenities The map below in Figure 1-1 indicates the site layout as per the tender submission. This layout is subject to change once the construction team is mobilised. Dam Wall, right abutment monolith, main spillway and left abutment Fabrication and Storage Beds for anchors, Office Figure 1-1 Site layout Page 5 of 86

6 Purpose of Proposed Operation and Major Steps Keepit Dam is currently rated as having a high safety risk, with extreme consequences of failure. The purpose of the proposed operation is to reduce the risk of failure of the dam wall and achieve compliance with the requirements of the NSW Dams Safety Committee. This will be undertaken through a two stage process Stage 1 and Stage 2. Stage 1 This package has been completed by John Holland. Stage 2 WaterNSW has had the electrical plant and upgrade works completed and has elected to implement the construction of the remaining works under Stage 2 under 2 separate works packages namely: - Package 2 Post Tensioning Works on the Main Dam Wall; - Package 3 Dam Raising and Associated Works. This Safety Study is for Stage 2, Package 2 Post Tensioning Works. Existing Operations Existing operations at Lake Keepit include; - The running of the existing Keepit Dam by WaterNSW; - The caravan park and camping grounds including the general store; - The Sailing Club; - Farming and private residences. Major Contractors A large proportion of Stage 2, Package 2 works will be self-performed by SRG Civil Pty Ltd employing local tradesmen. Specialist works and other works that the local market cannot cater for will be subcontracted. Sub contractors that may be used include; - Ok Steelfixing Steel Fixing; - Hiway Concrete Concrete Supply. Page 6 of 86

7 2. REQUIREMENTS OF THE CONSTRUCTION SAFETY STUDY Condition 2.12 of the Project Approval for Keepit Dam Update requires that a Construction Safety Study Report be prepared. The relevant requirements stipulated by the Conditions of Approval are detailed in Table 3-1. Table 2-1 Conditions relevant to the safety study CoA No. Condition 2.12 Prior to the commencement of construction of the project, the Proponent shall: 2.12(a) 2.12(b) 2.12(c) 2.12(d) 2.12(e) Prepare and submit for the approval of the Director- General a Construction Safety Study. This study shall cover all relevant aspects details in the Department s Hazardous Industry Planning Advisory Paper No. 7 Construction Safety Study Guidelines. The Proponent shall include a safety management plan as part of this study, in consultation with relevant authorities, addressing the safety of construction workers in the event of a flood, bushfire and other likely hazard or risk; Erect signs and fencing as necessary, to ensure the safety of bushwalkers etc near the site during construction; Provide adequate fire protection works on site during construction in consultation with the NSW Rural Fire Service; Ensure that all dangerous goods and materials stored on site are stored in accordance with the relevant Australian Standards; and Ensure that all explosives and fuel are removed from the site or disposed of appropriately at the completion of construction work. Where addressed Dam Safety Management Plan, Keepit Dam Risk Register and Checklist for HIPAP No.7 & See Appendices 7, 2 and 6 respectively Dam wall closed to Public, whole site fenced off to keep public away from construction works, Risk Register item 80 Rural Fire Service have been consulted and we have been put on the Duty Roster. Latest contact was on 24/4/17 by phone and . Risk Register items 16, 144 and 151 Keepit Dam Risk Register items 143,146, 148 & 151 Explosives are not required for this part of the work and will not be on-site. Fuel is used and will be removed from site at the end of the project refer to Keepit Dam Risk Register item 146 Page 7 of 86

8 3. STUDY METHODOLOGY The methodology used in undertaking this Construction Safety Study Report (CSSR) was to follow the recommended content and structure as detailed in Construction Safety Guidelines Hazardous Industry Planning Advisory Paper No.7 Department of Planning (1992). The project was then broken down into the basic tasks / activities as per the SRG program (see Appendix 1), and then identified the major hazards associated with each task and proposed appropriate safeguards for these hazards. This process is a procedure within SRG Civil and is set into our Risk Register. The Risk Register is reviewed as detailed in our Work Health Safety Management Plan Rev 3 dated 2 March 2017 (WHSMP), to ensure the safe guards are working and adequate for the hazards identified. This iterative process allows for changes to be flagged and amendments made as required. Other studies being undertaken concurrently include the development of the WHSMP Rev 3, Construction Environment Management Plan Final (CEMP) and Dam Safety Management Plan. Page 8 of 86

9 4. HAZARDS IDENTIFIED & PROPOSED SAFEGUARDS The hazards identified and safeguards proposed are detailed in the Keepit Dam Risk Register. Only the construction phase of the project has been examined. There is no demolition or commissioning phase associated with this project. The Risk Register flags possible hazards associated with the project and indicates whether a more in depth study of the construction activity is required based on the hazards identified and the inherent risk scores. An inherent risk score of high or extreme will automatically require the development of a Work Method Statement (WMS). The WMS document covers a single specific Workplace Activity developed in the Risk Register. An example of this would be a WMS for Anchor Block Coring Right Abutment Spillway. The WMS is then broken down further into Safe Work Method Statements (SWMS) within the WMS. The WMS document for each activity is developed after site mobilisation and site survey evaluation have taken place to ensure site specific hazards/issues are identified correctly and accurately. Further to this the direct involvement of sub contractors (not yet finalized) is required. The WMS document is facilitated by the Engineer responsible for the area of work/activity and is developed through input from and mandatory consultation with; - Site Project Manager; - Site Superintendent; - Safety, Quality and Environmental Representatives for the Project; - Project and Site Engineers; - Foremen; - Sub Contractors. The SWMS is developed at the start of the task to be undertaken and involves the supervisor of the work and the work group performing the task. An example of a SWMS to be developed from the above-mentioned WMS would be a SWMS for coring of holes for anchor blocks. Some of the key hazards identified in the WMS for the project include; - Flooding; - Working at Heights; - Damage to existing infrastructure; - Working with Plant & Equipment; Page 9 of 86

10 - Re fuelling of Plant & Equipment; - Environment incident; - Asbestos removal. Working with Plant & Equipment As set out in our risk register the interaction between plant equipment and people will be controlled by developing procedures to minimise the interaction between the various elements. Use of engineered solutions for the support of the various pieces of plant that will be required to carry out our work in the spillway. Working at heights We will use engineered solutions to obtain access to the spillway crest to carry out our contracted works. These engineered solutions will come with handrails, kick boards etc to contain our workforce so to remove the potential to fall from heights Asbestos removal A small amount of asbestos pipe has been identified cast into the concrete of the dam. In the process of carrying out our work we will been required to core through this pipe in a couple of locations. Processes are being developed which will estimate the volume of asbestos that will be removed and the methods of coring with water & capturing waste water and isolating this from those doing the coring and all personnel on site. This waste material will then be disposed of in the correct method, this will all be done in consultation with a registered asbestos contractor. Flooding SRG will be advised by WaterNSW of any impending flood event, and as such we will follow the procedures set out in the Dam Safety Management Plan Appendix 7 Section 5.5. This is basically that we will be instructed by WaterNSW that a flood event will be occurring and we will follow all instructions as directed by WaterNSW site personnel. Keepit Dam Risk Register See Appendix 2 for Keepit Dam Risk Register. The Keepit Dam Risk Register is a live document which is reviewed as per the WHSMP requirements. Page 10 of 86

11 5. ASSESSMENT OF OPERATIONAL SAFEGUARDS SRG Civil employ a number of processes and procedures to ensure all operational safeguards identified are in place and adequate. These include; - Regular review of the Risk Register as per the WHSMP; - Development of WMS s are included as hold points in the construction program (see Appendix 1 Draft Construction Program); - SWMS implementation audits as detailed in Section 12 Targets of the WHSMP; - Safety and Quality Audits as denoted in Section 12.2 Audit and Inspection of the WHSMP; - Safety targets including as denoted in Section 6.2 Objectives & Targets of the WHSMP; - Safety Buddy Walks incorporating Site staff, workforce and Senior Management; - Key performance indicators such as LTIFR, TRIFR and safety meters as detailed in the WHSMP. Further to this SRG have procedures and accompanying permits for a whole range of specific construction activities that are required to be adhered to when carrying out the activity, some of which can be found in the appendix 5. - Work at height; - Work on Water; - Hot Work; - Electrical equipment including testing and tagging; - Significant Lifts; - Traffic Management; - Scaffolding; - Excavation and Trenching; - Plant and Equipment; - Training. Page 11 of 86

12 6. SAFETY ASSURANCE SRG Civil has a Quality Management System that is third party certified to AS/NZS ISO9001:2008 and has a multitude of policies and procedures related to this standard that ensure SRG Civil Projects are constructed to the highest quality standard, with the intended aim of surpassing client expectations. SRG Civil has a vision of Zero Harm which is championed by Senior Management and is a culture by which the business operates. The SRG Civil Policy Statements (Appendix 3) are what the project will base its objectives on and give good incite as to how we aim to achieve the assurance of safety for this project. Involvement of all participants Is managed through the roles and responsibilities matrix in the DSMP section 7 in appendix 7. Documentation Is managed through the Project Quality Management Plan Keepit Rev 3 (QMP) and other SRG Civil procedures. The project personnel responsible for implementation, monitoring and review of these procedures is documented in the roles and responsibilities matrix in the QMP (under development). All these procedures will be forwarded to Water NSW for his approval prior to the work commencing. Materials of Construction Materials used for construction will be as specified in the contract documentation and drawings. Compliance with the specified materials will be ensured through Quality ITPs and Checklists developed in accordance with the QMP, relevant SRG Civil procedures, contract specifications and Australian Standards. Testing of materials will be by NATA approved laboratories as and when required and specified in contract. Fabrication There will be a requirement for fabricated items, all materials required to be fabricated will be procured through suppliers that are ISO 9001 accredited. Installation A detailed Construction Program is developed which becomes the installation schedule. There are hold points / milestones within this program to develop WMS s. These WMS s will address the type of quality documents required for each activity. The roles and responsibilities matrix within the QMP will nominate who is responsible for the documentation of installation for each activity. Engineers in charge of each section of works will regularly inspect the installation works. These inspections will include, Pre concrete pour checks, checks of steel reinforcing for correct sizes, lengths, laps etc, cover to concrete, Grout quality sampling, ensuring specifications are met and other inspections as indicated by the Quality ITP s and Checklists. Page 12 of 86

13 Critical verification/safety reviews Critical verifications are built into both the program and Quality ITP s as hold points. No work can commence until a hold point is signed off by the Client Superintendent as specified in the contract terms and specifications. Safety reviews are carried out on and ongoing basis as detailed in the SMP. Training/Qualifications A detailed training plan is currently being developed and will indicate all requirements to ensure the proper construction of the project. Definitions of responsibilities The responsibilities matrix in the WHSMP indicates the responsibilities of all persons involved in the project from a safety aspect. The responsibilities matrix in the QMP indicates the responsibilities of all persons involved in the project from a quality aspect. Page 13 of 86

14 7. CONSTRUCTION PROGRAMS The construction program is attached in Appendix 1. It breaks the project down into the major activities to be undertaken. Each activity is accompanied by a WMS start milestone. These milestones indicate the requirement for detailed analysis of the activity from a Safety, Quality and Environmental perspective. Extent of Work In broad terms, the Works comprises: - demolition and concrete surface preparation works for dam monolith blocks comprising the left abutment non-overflow blocks, overflow sections and right abutment non-overflow blocks and downstream face of the spillway piers; - drilling of vertical holes for cable anchors through the existing concrete of left abutment non-overflow blocks, overflow sections and right abutment non-overflow blocks and into the foundation rock and completion of all waterproofing required as a prerequisite to installation of the cable anchor components; - drilling of inclined holes for cable anchors through existing concrete of the spillway piers; - supply of all cable anchor components for 91 strand and 65 strand anchors to the project site; - installation, including grouting, of all cable anchors into drill holes for dam monolith blocks and spillway piers; - supply and installation of precast anchor head blocks for cable anchors in the dam monoliths blocks; - drilling and grouting starter bars and reinforced concrete construction for the spillway piers; - stressing of cable anchors to specified design loads; - supply and installation of metal covers for cable anchor installations including all associated corrosion protection for cable anchors and covers; - drilling of drain holes through concrete from cable anchor pits to downstream face of dam; - drilling of hole through concrete for vent pipe installation; - supply and installation of miscellaneous items of metalwork; - miscellaneous concrete construction. Page 14 of 86

15 Concrete Works Concrete works include spillway pier anchor bearing pad and miscellaneous concrete to various pits. Concrete supply will be by way of an off-site batch plant. Concrete mix design and trial mixes will be developed and tested to ensure compliance with specification requirements. All formwork and falsework drawings will be certified by a suitably qualified temporary works designer and proof checked. A letter of certification will be provided. Formwork will be fabricated for the spillway bearing pads. It will be installed in panels of suitable size for the crane used. The formwork fabrication and erection will be self-performed by SRG Civil. Reinforcing steel will be inspected during unloading to ensure the delivery matches the accompanying schedule. Steel deliveries will be timed so that steel is not sitting on site for an extended period of time. The steel fixing will be subcontracted out to a specialist steel fixing company. Prior to any concrete pour the SRG Civil surveyor will check position of forms, unformed surface level marks, screed rail levels, concrete cover to unformed surfaces and position of cast in items. The SRG Civil Engineers will check reinforcing bar size, location and quantity, concrete cover to formed surfaces, cleanliness and quantity and type of cast in items. Most concrete pours will be placed by a mobile pump and compacted with concrete vibrators. Anchor Fabrication Cable anchors will be fabricated on-site in propose built fabrication bed which will allow the strand to be opened up and pass through a grease bath to ensure that all the strand interstices are completely filled with grease. The strand is then inserted into HDPE sheath after a plug of grease has been injected into the sheath for the free length. Once the strand has filled the free length sheath drop the grease bath from the strand and continue to push the bond length of the anchor. Repeat this for the no. of strands required for the cable anchor laying them out on the fabrication bed. Page 15 of 86

16 Clean the individual bond length of each strand and place into the fabrication bed. Once all the strands have been run start to assembly the anchor as per the fabrication dwg and prepare for removing to storage bed. Cable Anchor Hole Drilling The use of purpose built drilling equipment will be used to drill all cable anchor holes. These rigs will be operated using hydraulic power packs to align, raise and lower the hammer tooling in the hole. The hammer will be of the down hole hammer type (DHH) which is powered by 3 air compressors which produce 1100cfm at 350 psi each. Air will assist with the removal of drill waste to settlement ponds by way of waste line which will operate across the dam crest. Cable Anchor Hole Testing On completion of drilling the hole to depth as required by the drawings each cable hole will have to be surveyed, have a video camera lowered down to record concrete condition, concrete rock interface and condition of rock and tested for water tightness. On completion of these items the cable hole will be assessed to see if it requires waterproof grouting in conjunction with WaterNSW before proceeding with the installation of the anchor. Waterproofing Grouting of Cable Anchor Hole Upon receiving direction to waterproof grout cable anchor hole set up grout station and environmental controls prior to grouting. Lower tremmie pipe to bottom of cable hole, now ready to start mixing grout as per the requirements in the specification. Continue grouting to the desired level as per agreement with WaterNSW. On completion of grouting remove grout gear and set drill rig ready to re-drill hole once grout is old enough. Once grout is of sufficient age re-drill hole using similar method to that above. Anchor Installation Set up installation frame (Dinosaur) over cable anchor hole which cable anchor is to be installed into. Put anchor on trolleys and transport to dam crest. Page 16 of 86

17 Align trolleys so anchor can be feed onto Dinosaur, at this stage attach breaking winch to lifting head of anchor tail end of cable anchor. Feed cable anchor onto Dinosaur using Dinosaur feeding winch, at some stage weight of anchor being deed over Dinosaur will be heavier than that not over Dinosaur and rate of descent will be controlled by the breaking winch. Continue to install cable anchor until in right position and transfer cable anchor to support frame to allow grouting of anchor to proceed. Anchor Grouting Set up grout station for cable anchor grouting including all environmental controls. Mix Bond length grout into holding tank carrying out all necessary quality checks prior to grouting. Starting grouting of bond length ensuring inner and outer annuli are rising at the same rate Continue grouting until we get return of water from secondary grout hoses, at this stage Anchor stressing Stress cable anchor in stages as per the specification taking into account location and handling technics for the stressing gear. Page 17 of 86

18 8. MANAGEMENT OF CHANGE The SRG Civil WHS management Plan, Quality Management Plan and CEMP all have procedures which allow the continual improvement of the processes with the plans. Where there is a permanent modification of hardware or operational safeguards or program modification during the construction phase of the project, the risk Register will be reviewed. This review will be undertaken by those involved in its development and will indicate whether further action must be taken including review and change of WMSs and SWMSs. Page 18 of 86

19 9. GLOSSARY & ABBREVIATIONS WMS SQE SQERM Work Method Statement Safety, Quality & Environment Acronym used to describe the integrated Safety, Quality & Environment Risk Management process. SWMS Keepit Dam Risk Register WHSMP ITP QMP OHS&R LTIFR TRIFR CEMP CSSR DSMP Safe Work Method statements Workplace Risk Register of all risks associated with the project Work Health Safety Management Plan Inspection and Test Plan Quality Management Plan Occupational Health, Safety and Rehabilitation Lost Time Injury Frequency Rate Total Recordable Injury Frequency Rate Construction Environmental Management Plan Construction Safety Study Report Dam Safety Management Plan Page 19 of 86

20 APPENDIX 1 Draft Construction Program Page 20 of 86

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23 APPENDIX 2 Keepit Dam Risk Register Page 23 of 86

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49 APPENDIX 3 Hazardous Materials Register Below is list of Hazardous Materials which will be used on site and storage as per AS Item Chemical/Substance Manufacturer/Supplier Application 1 Diesel Lowes Fuel for plant & equipment maximum at any one time is 8,300 litres in abunded tank of 10,000 litre capacity 2 Cement Eureka For site manufacture of grout 3 Moly Grease L H S Rock Rod Grease 4 Biodegradable Hammer Oil AMC Oil for Down Hole Hammer 5 Epoxy Grout Epirez Grouting of Bearing Plates 6 Masterbrace Epoxy 1446 Part A & B 7 Denso Void Filler #1 & #2 Masterbrace Denso Grouting of Nose Cones Void filler for manufacture of Anchors Page 49 of 86