Gas Drainage Management Plan

Transcription

1 Gas Drainage Management Plan

2 Table of Contents 1 INTRODUCTION BACKGROUND OBJECTIVES DISTRIBUTION LEGISLATIVE REQUIREMENTS AND PROPOSED PERFORMANCE STANDARDS LEGISLATIVE REQUIREMENTS Environmental Protection Licence Requirements NSW Code of Practice for Coal Seam Gas Well Integrity (2012) NSW Aquifer Interference Policy PROJECT APPROVAL CONDITIONS Previous Project Approvals Bulli Seam Operations Project Approval GAS DRAINAGE INFRASTRUCTURE OVERVIEW STANDARDS FOR BOREHOLE DEVELOPMENT Recording and Reporting Data Well and Drilling Program Design Borehole Monitoring and Maintenance Well Abandonment/Rehabilitation PLAN ADMINISTRATION ROLES AND RESPONSIBILITIES RESOURCES REQUIRED TRAINING RECORD KEEPING AND CONTROL DOCUMENT CONTROL MANAGEMENT PLAN REVIEW ENVIRONMENTAL MANAGEMENT PRACTICES REHABILITATION STRATEGIES Objectives Guidelines and Standards Post-Construction Infrastructure & Landscape Rehabilitation Outcomes Post-Gas Drainage Infrastructure & Landscape Rehabilitation Outcomes AIR QUALITY MANAGEMENT STRATEGIES GREENHOUSE GAS MANAGEMENT STRATEGIES WATER MANAGEMENT STRATEGIES EROSION AND SEDIMENT MANAGEMENT STRATEGIES NOISE MANAGEMENT STRATEGIES FLORA AND FAUNA MANAGEMENT STRATEGIES TRAFFIC MANAGEMENT STRATEGIES Rev 4.1 ii

3 6.9 WASTE MANAGEMENT STRATEGIES CULTURAL HERITAGE MANAGEMENT STRATEGIES VISUAL IMPACT MANAGEMENT STRATEGIES PUBLIC SAFETY REFERENCES ATTACHMENT 1. INDICATIVE LAYOUT FOR APPIN EAST FLARES Tables Table 2.1. Schedule 4 Condition 21 Bulli Seam Operations Project Approval... 3 Figures Figure 3.1. Schematic Pre-mine Drainage Borehole... 6 Figure 3.2. Schematic Post-mine Drainage - MRD... 7 Figure 3.3. Schematic Post-mine Drainage - Vertical wells... 8 Figure 3.4. Borehole Drilling Infrastructure Images... 9 Figure 3.5. Drill Montage Pre-mine drainage borehole Figure 3.6. Drill Montage MRD Borehole Figure 3.7. Drill Montage Vertical Borehole Rev 4.1 iii

4 Review History Revision Description of Changes Date Approved 1 New document February Revised document March Revised Document address DoPI comments May Revised Document gas plant upgrades November Revised Document gas plant upgrades (incorporating DPE feedback) Persons involved in the development of this document include: December 2016 Name Title Company Cassy Baxter Environmental Scientist Cardno Daniel Thompson Senior Environmental Planner Cardno Bruce Blunden Manager Approvals (Surface) Illawarra Coal Adam West Specialist Approvals Illawarra Coal Rev 4.1 iv

5 1 INTRODUCTION 1.1 BACKGROUND Illawarra Coal (IC) proposes to continue underground coal mining operations at its Bulli Seam Operations, located in the Southern Coalfield of New South Wales. Coal is extracted from the Bulli Seam using longwall mining techniques. In order to support the safe and efficient extraction of coal from the Bulli Seam, IC proposes to continue surface gas drainage works and operations. All coalmines with high coal seam gas concentrations are required to have procedures for controlling concentrations of methane gas. Surface gas drainage wells can extract methane from within the coal seam prior to mining or from within the goaf during mining operations. The purpose of surface gas drainage is to provide a safe and efficient underground mining environment. The gas drainage ensures underground methane concentrations remain well below 1.25%, minimising the potential for gas from entering the workings of the mine and the Mine Ventilation Air (MVA). The works associated with this Gas Drainage Management Plan (GDMP) are a continuation of the activities approved under Major Project Approvals 08_0256 and 07_0073. Condition 4.21 of the Bulli Seam Operations, Project Approval 08_0150, which is included in Section 2.2.2, requires the development of the GDMP. 1.2 OBJECTIVES The objectives of this GDMP are: To comply with Bulli Seam Operations Consent Condition 4.21, with regards to vegetation clearing and rehabilitation, noise, air quality, biodiversity, heritage, groundwater, surface water and erosion and sediment control, as well as management and monitoring proposed in response to the proposed gas drainage infrastructure; To improve mine safety during first working development and longwall extraction; and To minimise Greenhouse Gas Emissions (GHGs). 1.3 DISTRIBUTION The GDMP and other relevant documentation is publicly available on the South32 website as required by Condition 6.11 of the Bulli Seam Operations Project Approval (08_0150). 2 LEGISLATIVE REQUIREMENTS AND PROPOSED PERFORMANCE STANDARDS 2.1 LEGISLATIVE REQUIREMENTS A GDMP is required to be approved by the Secretary of the Department of Planning and Environment (DPE) in accordance with the requirements of Condition 4.21 of the Bulli Seam Operations Project Approval (08_0150), which was granted on 22 December 2011 in accordance with the Environmental Planning and Assessment Act 1979 (EP&A Act). Other NSW legislation relevant to this Project includes: Protection of the Environment Operations Act 1997 (POEO Act); Threatened Species Conservation Act 1995; Soil Conservation Act 1938; Rev 4.1 Page 1

6 Water Act 1912 and Water Management Act 2000; The NSW Industrial Noise Policy, NSW Code of Practice for Coal Seam Gas Well Integrity, NSW Aquifer Interference Policy and NSW Minerals Industry Due Diligence Code of Practice for the Protection of Aboriginal Objects (NSW Minerals Council 2010), are also relevant Environmental Protection Licence Requirements The POEO Act 1997 is the key NSW Government legislation with respect to protection of the environment. The Environmental Protection Authority (EPA) administers this Act. The POEO Act permits the granting of Environmental Protection Licences (EPL) to regulate industrial activity. Illawarra Coal holds EPL 2504 for its Bulli Seam Operations. The proposed gas drainage development does not require an EPL because the proposed works do not meet any of the definitions within Schedule 1 of the POEO Act NSW Code of Practice for Coal Seam Gas Well Integrity (2012) The NSW Code of Practice for Coal Seam Gas Well Integrity provides a practical guide for undertaking Coal Seam Gas (CSG) exploration, extraction or production under the Petroleum (Onshore) Act 1991 and the Petroleum (Onshore) Regulation 2007 to ensure that well operations are safe, without risk to health and without detriment to the environment. The principles stated within this Code of Practice will be used in this GDMP to ensure maximum protection for workers, landholders and the environment throughout the project NSW Aquifer Interference Policy The Aquifer Interference Policy and Water Management Act 2000 address water licensing and assessment for aquifer interference activities. Aquifer interference includes the penetration of an aquifer which can occur during the gas drainage process. Under this policy, mining activities and coal seam gas activities are defined as high-risk activities. Appin Mine was granted a Special Purpose (Mine Dewatering) License on 19 February 2013 in accordance with the Water Act On the 2 nd of May 2014, Appin Mine was granted Water Access Licence under the Water Management Act Groundwater extracted during pre-mining Mine Safety Gas Drainage activities will be in accordance with the requirements of this License. No groundwater extraction would occur during the postmining Mine Safety Gas Drainage activities. All boreholes are cased and grouted to prevent interference with groundwater. Consequently, there is no impact on groundwater from the Mine Safety Gas Drainage activities and interference of an aquifer would not occur. 2.2 PROJECT APPROVAL CONDITIONS Previous Project Approvals The Appin Gas Drainage Major Project Approval (MP 08_0256) was granted by the Minister for Planning on the 2 nd October 2009 for the drainage of goaf gas from Longwalls 703 to 704. This approval was followed by two subsequent Section 75W modifications. In December 2010 a modification was approved to relocate Medium Radius Drilling (MRD) wells and a vertical borehole, as well as upgrade existing access roads and construct a new section of access road Rev 4.1 Page 2

7 In February 2012 a modification was approved to construct and operate an additional seven vertical drainage wells, with connecting trenched pipelines and access tracks for Longwall 704; and construct and operate five vertical and up to six MRD gas drainage wells, with connecting pipeline and access tracks for Longwall 705. The BSO Gas Drainage Management Plan, including Appendix A (Appin Longwalls 706 to 708) was approved by the Department of Planning and Environment on the 22 nd May Appendix B of the Gas Drainage Management Plan was approved on the 24 th September 2015 for a proposed MRD borehole addressing Appin Longwall 901 extraction. The West Cliff Surface Gas Drainage Project Approval (MP 07_0073) was granted by the Minister for Planning on the 8 th December 2008 for the drainage of goaf gas from Longwalls This approval was followed by two subsequent Section 75W modifications. On the 27 th October 2012, the Department of Planning and Infrastructure approved a Gas Drainage Management Plan in accordance with Condition 4.21 of MP 08_0150 for West Cliff Longwalls Longwall extraction at West Cliff mine is complete and therefore no further gas drainage wells are planned for this area. Gas drainage facilities associated with each longwall are rehabilitated as mining progresses beyond the site and the volume of gas reporting to each well greatly reduces, or ceases. As such, the management plan requirements progressively become redundant once the longwalls have been completed, boreholes sealed and sites rehabilitated to the appropriate standards and/or the requirements of the landholder Bulli Seam Operations Project Approval An Environmental Assessment was submitted in October 2009 for the continuation of underground mining operations at the Appin and West Cliff Collieries (herein referred to as the Bulli Seam Operations Project) in accordance with Part 3A of the Environmental Planning and Assessment Act, 1979 (EP&A Act). The Bulli Seam Operations Project Approval (MP 08_150) was granted by the Planning and Assessment Commission on 22 nd December 2011 and is available at This Bulli Seam Operations Project Approval includes approval conditions specifically for gas drainage management. The relevant Project Approval condition (Condition 4.21) is outlined in Table 2.1. Table 2.1. Schedule 4 Condition 21 Bulli Seam Operations Project Approval Project Approval Condition Relevant GDMP Section Gas Drainage Management Plan 21. The Proponent shall prepare and implement a Gas Drainage Management Plan in respect of construction and use of future gas drainage infrastructure (i.e. for any gas drainage not subject to approval at the date of this instrument) to the satisfaction of the Secretary. This plan must be submitted to the Secretary for approval prior to the construction of any future goaf gas drainage infrastructure and must include details of the proponent s commitments regarding: a) community consultation; b) landholder agreements; Appendix A Section Rev 4.1 Page 3

8 Project Approval Condition c) assessment of noise, air quality, traffic, biodiversity, heritage, public safety and other impacts in accordance with approved methods; d) avoidance of significant impacts and minimisation of impacts generally; e) flaring or use of drained hydrocarbon gases, wherever practible; Relevant GDMP Section Section 6 and Appendix A Section 3 Appendix A Section 3 Section 3 f) achievement of applicable standards and goals; Section 6.1 g) mitigation and/or compensation for significant noise, air quality and visual impacts; and Appendix A Section 3 h) rehabilitation of disturbed sites. Appendix A Section 3 This document has been prepared to comply with the Bulli Seam Operations Project Approval conditions above. 3 GAS DRAINAGE INFRASTRUCTURE 3.1 OVERVIEW Gas drainage infrastructure consists of a series of boreholes drilled to a depth of approximately 500m through which methane gas will be drained via a surface pipeline reticulation system connected to a gas extraction plant. After being extracted by the extraction plant on the surface, the majority of the methane gas is piped back underground to the existing underground connection to one of the Energy Developments Limited (EDL) Power Stations where it will be used to generate electricity. The BSO Project identified upgrades to the existing gas drainage plants located adjacent to the EDL Power Stations to ensure ongoing efficiency in the extraction process and to minimise the environmental impact of gas produced from mining operations. These upgrades include the installation and operation of flaring facilities to reduce venting to atmosphere. An image of the type of flaring units used for the upgrades identified in the BSO Environmental Assessment is in Figure 3.4, while an indicative layout for the Appin East upgrades proposed for late 2016-early 2017 are also included as Attachment 1. Further upgrades may occur to these facilities over time. Should borehole gas flows exceed the capacity of the extraction plant and associated existing management infrastructure, and/or during plant breakdown/maintenance periods, the excess gas is flared via onsite flaring units. Where gas cannot be flared, or in an emergency, gas may be vented to the atmosphere. Depending on the quality and volume of gas extracted, it may be reticulated to other beneficial users. This GDMP applies to all phases of gas drainage undertaken to ensure mine safety and minimise GHG emissions before and during the extraction of coal via longwall mining. Site-specific environmental assessments and descriptions of specific management arrangements for gas drainage management activities will be progressively appended to the GDMP. The generic management activities in the GDMP are implemented at all gas drainage infrastructure sites and systems Rev 4.1 Page 4

9 Illawarra Coal s MSGD program is comprised of two key phases: Pre-mine Drainage MSGD is undertaken to reduce methane concentrations in the coal seam where development roadways are to be constructed to support longwall extraction. This occurs prior to extraction of the longwalls. The in-seam methods and surface to seam boreholes extract gas from the coal seam prior to the commencement of mining. The pre-mine drainage surface boreholes start vertically and are then steered to a near horizontal alignment within the coal seam to extract gas and water prior to the extraction of coal. The horizontal boreholes are aligned with the development roadways that define a longwall block proposed for extraction. Any water that is extracted during MSGD is stored temporarily within a tank onsite, prior to being taken to Appin Mine, or an alternate appropriately licensed facility (refer to Figure 3.1 for a schematic illustrating the pre-mine drainage well infrastructure; and Figure 3.4 for an image of the borehole drilling infrastructure). Post-mine Drainage The methane is drained from the goaf areas during longwall extraction via surface boreholes. Two types of boreholes are utilised: 1. Vertical boreholes - comprising a vertical borehole drilled to the goaf area above the Bulli coal seam (approximate depth 450m). 2. Medium Radius Drilling (MRD) boreholes - comprising a borehole that starts vertically and is then steered to a near horizontal alignment for a known distance within sandstone strata above the coal seam. The MRD boreholes can have a number of branches to improve gas flow and maximise MSGD during-mining, which end approximately 5m above the coal seam roof (refer to Figure 3.2 and Figure 3.3 for a schematic illustrating the MRD and Vertical borehole infrastructure and 3. Figure 3.4 for an image of the borehole drilling infrastructure). During the operational phase, all boreholes have gas flow metering and control systems in place at the wellhead. These systems are enclosed in green colourbond sleds to minimise visual amenity impacts. Figure 3.4 illustrates operational phase infrastructure during gas drainage. 3.2 STANDARDS FOR BOREHOLE DEVELOPMENT Recording and Reporting Data IC records the well life cycle for each borehole. This includes the layouts; engineering designs; risk assessments and assumptions; specifications of equipment and well design; installation records; core descriptions (where relevant); Daily Drilling Reports and completion reports. Reporting is undertaken as per the relevant approvals or guidelines. This varies depending on the purpose of the activity and the primary approval agency. Generally, reporting is undertaken as follows: Government approvals (DTI, DPE) Additionally, other government agencies may also require notifications under these approvals including the DTI Mine Safety Inspector, DTI Environment Department, Office of Environment and Heritage (OEH)/Environmental Protection Authority (EPA) and/or WaterNSW Rev 4.1 Page 5

10 Figure 3.1. Schematic Pre-mine Drainage Borehole Rev 4.1 Page 6

11 Figure 3.2. Schematic Post-mine Drainage - MRD Rev 4.1 Page 7

12 Figure 3.3. Schematic Post-mine Drainage - Vertical wells Rev 4.1 Page 8

13 Figure 3.4. Borehole Drilling and Gas Management Infrastructure Images Vertical Borehole drilling Pre-mine MSGD Borehole drilling Rev 4.1 Page 9

14 MRD Borehole drilling Area 7 Extraction Plant Rev 4.1 Page 10

15 Horizontal Flares Vertical Flares (as used at permanent facilities) Rev 4.1 Page 11

16 Well head control sleds Well and Drilling Program Design IC well designs meet the American Petroleum Institute (API) Standards to ensure safe and environmentally sound installation and operation. The design of each well is dependent on whether it is a: Pre-mine drainage steered or vertical borehole; Mine safety gas drainage MRD borehole; or Mine safety gas drainage vertical well. Drill montage schematic diagrams outline typical details of these boreholes, including the casing, grouting, and the drilling fluids for each section (refer to Figure 3.5, 3.6 and 3.7). Beyond the API Standards, IC also incorporate guidance from the NSW Code of Practice for Coal Seam Gas Well Integrity, DPE and DTI project approval requirements; and IC/South32 requirements. Drilling fluids used for IC projects are water based (i.e. not oil based), in line with the Code of Practice for CSG. The source of water is determined in the project scoping and is generally potable water, or potentially from a farm dam or licensed extraction point, wherever such a source is available. IC have a comprehensive assessment and internal approval process in place for any chemicals for drilling operations. Products are reviewed for their health, safety and environmental properties and the way in which they will be used. Biodegradable products are preferred. Cuttings and liquids are either disposed of at a licensed facility, or where suitable, utilised at West Cliff Emplacement Area Rev 4.1 Page 12

17 3.2.3 Borehole Monitoring and Maintenance Mine safety gas drainage boreholes are monitored and maintained on a regular basis during gas extraction. This involves on-site monitoring and continuous monitoring through Supervisory Control and Data Acquisition (SCADA) systems. Monitoring is in line with the requirements of the CSG Code of Practice Well Abandonment/Rehabilitation After gas drainage operations are no longer required, all boreholes are plugged in accordance with the DTI Standard EDG 01, Exploration and API standards and the requirements of the CSG Code of Practice. All wellhead infrastructure and pipelines are removed, and the drilling pad is rehabilitated to the former landuse, or as agreed with the landholder Rev 4.1 Page 13

18 Figure 3.5. Drill Montage Pre-mine drainage borehole Rev 4.1 Page 14

19 Figure 3.6. Drill Montage MRD Borehole Rev 4.1 Page 15

20 Figure 3.7. Drill Montage Vertical Borehole Rev 4.1 Page 16

21 4 PLAN ADMINISTRATION This GDMP is in accordance with the requirements of the Bulli Seam Operations Environmental Management System (EMS) and the Bulli Seam Operations Project Approval (MP08_150). A summary of the administrative requirements is provided below. 4.1 ROLES AND RESPONSIBILITIES It is the responsibility of all employees and contractors to undertake practices to manage and minimise potential environmental impacts according to this GDMP. The Specialist Approvals is responsible for coordinating the implementation and periodic review of this GDMP. The Specialist Approvals and Specialist Energy and Surface Gas will also be responsible for ensuring the commitments contained within this GDMP are met. This will include: 1. Overseeing the operation and maintenance of site preparation, site water management and sediment and erosion control; 2. Overseeing the operation and maintenance of noise monitoring and mitigation; 3. Overseeing drill site and pipeline rehabilitation; andpreparing and disseminating reports and information. The Specialist Community is responsible for consulting with landowners, neighbours and members of the community regarding the activities outlined in this GDMP. All statutory obligations applicable to the Bulli Seam operations are identified and managed via an online compliance management system (TICKIT). 4.2 RESOURCES REQUIRED It is the responsibility of the Gas & Ventilation Superintendent and Principal Mining Approvals to ensure that resources are provided to implement the GDMP. 4.3 TRAINING All staff and contractors working on IC sites are required to complete the IC training program, which includes: An initial site induction (relevant aspects of environment, safety and community). Safe Work Method Statements and Job Safety Analyses, Toolbox Talks and Pre-shift communications. On-going job specific training and re-training (where required). All training records are maintained in the STAX database system. It is the responsibility of the Principal Mining Approvals and Gas & Ventilation Superintendent to ensure that all persons and organisations having responsibilities under this GDMP are trained and understand their responsibilities. The person(s) performing regular inspections are trained in observation and reporting. The Specialist Approvals shall be satisfied that the person(s) performing the inspections are capable of meeting and maintaining this standard Rev 4.1 Page 17

22 4.4 RECORD KEEPING AND CONTROL Environmental Records are maintained in accordance with the IC procedure Records Management (ICHP0108). 4.5 DOCUMENT CONTROL The IC Document Control procedure (ICHP0103) outlines the method for control of defined business critical documentation for all IC operations. The system ensures that: Documents are approved for adequacy by authorised personnel prior to use. Obsolete documents are promptly removed from circulation. Documents are reissued to relevant persons in a timely fashion after changes are authorised. The GDMP and other relevant documentation is available on the IC website. 5 MANAGEMENT PLAN REVIEW Gas Drainage Operations are reviewed annually in accordance with Condition 6.4. More specifically this GDMP will be subject to review (and revision if necessary, to the satisfaction of the Secretary) following the completion of: The submission of an annual review under Condition 6.4. The submission of an incident report under Condition 6.7. The submission of an audit report under Condition 6.9. Any modification to the conditions of this approval. Any deficiencies identified in the EMS and/or GDMP will be rectified as required. This process has been designed to ensure that all environmental documentation continues to meet current environmental requirements, including changes in technology and operational practice, and the expectations of stakeholders. 6 ENVIRONMENTAL MANAGEMENT PRACTICES The GDMP considers the following environmental aspects in order to determine adequate management and mitigation measures. 6.1 REHABILITATION STRATEGIES Site management, mitigation and rehabilitation strategies ensure impacts on the surrounding environment are minimised Objectives The objectives of progressive rehabilitation for gas drainage management activities are to: Comply with all regulatory requirements set out in the Project Approval and other legislation with regards to rehabilitation management and monitoring; Ensure IC environmental and other relevant Strategies and Policies are met and upheld; Implement progressive rehabilitation of temporary construction-phase impacts associated with drilling operations; Rev 4.1 Page 18

23 Rehabilitation of all areas at the completion of operations, including plugging boreholes to avoid future groundwater interactions; Outline monitoring and performance evaluation measures that are practical; and Provide procedures associated with reporting the results of the monitoring Guidelines and Standards A number of guidelines and standards exist which govern and inform the mine closure and rehabilitation process. IC will refer to the appropriate Standards and Guidelines available at the time. At present, relevant guidelines include: EDG01 Borehole Sealing Requirements on Land; EDG03 Guidelines to the Mining Rehabilitation and Environmental Management Process - MREP Guideline; NSW Code of Practice for Coal Seam Gas Well Integrity. Department of Trade and Investment, Regional Infrastructure and Services; Mine Rehabilitation Leading Practice Sustainable Development Program for the Mining Industry (Commonwealth of Australia); Mine Closure and Completion Leading Practice Sustainable Development Program for the Mining Industry (Commonwealth of Australia); Strategic framework for Mine Closure (ANZMEC); Other relevant DRE NSW guidelines; and Appropriate South32 or IC guidelines and procedures Post-Construction Infrastructure & Landscape Rehabilitation Outcomes Rehabilitation works undertaken at the completion of the construction phase includes: Stabilising access road verges and internal roads; Use of top soil stockpiles to rehabilitate adjacent pastures; Removal of drilling infrastructure; Remediation of drilling sumps; and Pad consolidation Post-Gas Drainage Infrastructure & Landscape Rehabilitation Outcomes Rehabilitation works undertaken at the completion of the gas drainage phase includes: Removing well head infrastructure and pipelines; Plugging the borehole in accordance with EDG01 Borehole Sealing Requirements on Land and the NSW Code of Practice for Coal Seam Gas Well Integrity; Reshaping pads to the pre-project landform or as per landholder requirements; and Topsoiling and establishment of a stable, self-supporting landform (generally this will be pasture re-establishment unless determined otherwise by landholder consultation) Rev 4.1 Page 19

24 6.2 AIR QUALITY MANAGEMENT STRATEGIES Gas drainage has the potential to impact air quality through diesel emissions from stationary and mobile plant, and dust generated during the construction phase. Well-maintained equipment is used to limit impacts on air quality. The following mitigation and management measures ensure dust emissions are controlled: Exposed areas are watered to prevent dust; Dust generated during drilling is suppressed with water sprays; Stockpiles of topsoil and subsoil are replaced as soon as practicable. Re-vegetating or stabilising disturbed areas where necessary minimises wind-blown dust; and If necessary, dust-generating activities are modified during periods of high wind. Gas will be vented where it cannot be utilised or flared, or in emergencies. 6.3 GREENHOUSE GAS MANAGEMENT STRATEGIES IC use in-seam drilling to drain methane within coal seams prior to mining. Gas from strata is drained by cross measure boreholes. The in-seam and cross measure drainage produces mostly methane gas. Methane is a GHG that has a Global Warming Potential (GWP) of 21. Current best practice for the management of GHG emissions from underground coalmines involves the following: Minimising GHG emissions to the atmosphere; Maximising gas capture and utilisation for beneficial use; and Flaring which oxidises methane to carbon dioxide and water significantly reduces greenhouse gas emissions. Illawarra Coal supplies gas captured from underground and surface gas drainage systems to EDL for power generation. This power generation reduces the emission of greenhouse gasses by several million tonnes of CO2-e per annum. Where supply of this gas to a beneficial user (such as EDL) is not possible, then the methane is flared to minimise greenhouse gas emissions. 6.4 WATER MANAGEMENT STRATEGIES Gas drainage works have the potential to impact surface and groundwater and therefore implementation of measures to mitigate or minimise these impacts are included as part of the projects. IC has a comprehensive understanding of the geology, stratigraphy, aquifers and aquicludes, groundwater flow and water quality in the Bulli Seam Operations Project Area as described in Appendix B (Groundwater Assessment) of the Bulli Seam Operations Project Environmental Assessment. This Groundwater Assessment describes the groundwater regime and assesses the predicted impacts associated with mining and other activities such as gas drainage. In addition, Geoterra (2011) undertook a comprehensive groundwater assessment for the surface gas drainage works undertaken at Appin Mine. Given the stratigraphy of the region, which includes three aquitards which control the vertical flow of groundwater, coupled with the strict borehole construction techniques employed, no significant impacts to aquifers are predicted to occur. Groundwater extracted in the the area is predominately from the Hawkesbury Sandstone stratigraphic unit. Surface Gas Drainage boreholes in the Hawkesbury Sandstone are steel cased grouted through the entire depth of the Hawkesbury Sandstone, thereby preventing any interference with the flow or quality of the aquifer. No hydraulic fracturing or well stimulation is employed. IC monitors the aquifers that may be influenced by mining in the Bulli Seam Operations through an extensive array of multi-level piezometers Rev 4.1 Page 20

25 Illawarra Coal operates in accordance with Water Access Licenses for the interception of groundwater for mining purposes. Illawarra Coal implements the following water management strategies: 1. Water used for drilling and extraction plant operations is from a Sydney Water Authorised user or sourced from on-site farm dams in accordance with landowner approval or other licensed extraction point; 2. The walls of sumps will be of an appropriate height to provide adequate freeboard (approximately 0.5m) to prevent overflow during rainfall. The drilling sumps and pads have run-off diversion bunds in place to minimise runoff entering the sumps. The sides and base of the sumps are compacted to minimise any interaction with shallow groundwater. When feasible to do so, above ground sumps or tanks will be used to support drilling activities; 3. At the completion of drilling, water from drilling sumps will be transported to Appin Mine or other appropriately licensed facility for treatment and reuse. If drilling water is uncontaminated it may be irrigated onto nearby pasture. 4. All reasonable measures will be taken to prevent silt laden runoff from entering receiving waters. 5. Vertical boreholes will be steel cased and grouted from the surface to the top of the Bulgo Sandstone (refer to Figures 3.5, 3.6 and 3.7) to prevent interception of groundwater. 6. The MRD or steered pre-mine MSGD boreholes will be steel cased and grouted to the end of the radial or build section where the horizontal alignment and branching to the laterals of the borehole starts (~450m depth) to prevent any interception of groundwater; 7. The water used in the extraction plant cooling process is reused at Appin Mine or irrigated onto nearby pasture well away from drainage lines and farm dams. 8. Drilling sumps where required are compacted to ensure that contamination of groundwater does not occur. If there is potential for sump overflow, offsite disposal will be used. 9. Where it is practical to do so, IC will use above ground tanks or sumps during drilling. Gas drainage boreholes are cased to a depth below regionally significant groundwater aquifers and grouted to American Petroleum Institute Standards in order to prevent any interception or cross contamination of groundwater during gas drainage. No impacts to surface water, groundwater or surrounding vegetation have been observed during the Appin Surface GDMP since its inception. No evaporation ponds are utilised. No saline water is generated by the post-mine gas drainage works. Saline water is captured in above ground tanks and transported to an appropriately licensed facility during pre-mine gas drainage works. 6.5 EROSION AND SEDIMENT MANAGEMENT STRATEGIES Civil works have the potential to generate erosion and sediment laden runoff and therefore management measures are implemented to minimise these impacts. Erosion and sedimentation control measures are implemented in accordance with a Soil and Water Management Plan and the requirements of the Blue Book (Soils and Construction, Volume 1, 4 th edition July 2006, Landcom). The following management strategies are used: 1. Weekly inspection of site drainage and erosion/sediment controls and implementation of maintenance as needed; 2. Identification of drainage channels and effective management of surface water during construction and operation phases of work; Rev 4.1 Page 21

26 3. Revegetation and stabilisation of disturbed areas to minimise erosion and scour; 4. Reduction in the amount and velocity of any water flows over the construction site through the use of rip rap and bunding; 5. Installation of sediment filters or fences downslope of disturbed areas; 6. Installation of clean water diversion drains; 7. Minimising the length and duration of exposed excavations during pipe line laying. Where trenches and soil stockpiles are exposed for more than one-week silt fences are deployed adjacent to the disturbed areas on the downslope side. Soil stockpiles are placed on the uphill side of any excavated trench so that any sediment flows into the trench during runoff; 8. Maintain pasture adjacent to any disturbed areas and direct runoff to flow through pasture prior to any flow to waterways; 9. Maintain drilling sumps by treating sediment-laden water at the Appin Mine dirty water management system or on a well-vegetated pasture away from drainage lines. Drilling compounds are levelled to accommodate safe drilling operations. Cut/fill operations of generally less than 5,000m 3 are required. Crushed stone, gravel or coal wash is used to create working areas within the drill and extraction plant compounds or for access roads. All sediment control structures have sufficient capacity to trap sediment mobilised from cleared areas and sump overflows during normal rainfall events. Any overflow from sediment control structures is directed to grass paddocks. Pipelines are constructed to relevant extraction plants. Access is via formed roads or farm tracks already on site, and then follow the pipeline route for construction of the gas drainage boreholes, extraction plant compounds/flares and pipelines. Pasture is re-established on disturbed areas such as buried pipelines, drilling compounds and access routes (where it is reasonable and practical to do so) after construction is complete to minimise potential for sediment runoff. At the end of gas extraction, the extraction plant compounds, well heads and pipelines are decommissioned, removed and rehabilitated. The boreholes are rehabilitated in accordance with DTI requirements. Any cut/fill areas are reshaped to the original land surface unless requested by the landowner. The extraction plant and drilling compounds as well as the pipelines are rehabilitated in accordance with the Rehabilitation Protocol and/or landholder requirements as soon as possible after the completion of site decommissioning. 6.6 NOISE MANAGEMENT STRATEGIES Noise mitigation measures are tailored to address the noise generated at various stages of a project. Noise mitigation measures include: Orientating equipment so that the noisiest side faces away from sensitive receivers; Using noise walls erected as close as possible to noisy equipment or drill rigs; Using noise source controls, such as the use of residential class mufflers, to reduce noise from all plant and equipment including cranes, excavators and trucks; Using spotters, closed circuit television monitors, smart reversing alarms, or quacker type reversing alarms in place of traditional reversing alarms in sensitive areas; Selecting plant and equipment based on noise emission levels, including drill rigs; Optimising the schedule of truck deliveries to daytime periods; Using alternative construction methods to minimise noise levels; and Rev 4.1 Page 22

27 Providing alternative arrangements for temporarily affected residents, such as temporary relocation. 6.7 FLORA AND FAUNA MANAGEMENT STRATEGIES The following actions are implemented to mitigate potential impacts to flora and fauna: Where possible, adjust the location of boreholes and sections of surface gas pipelines to avoid native trees and significant habitat features such as trees with hollows; Where possible, trees with hollows would be retained and protected, with no drilling within the critical root zone (extending to 2m beyond the drip line) of the trees; Where possible, boreholes, pipelines and access tracks would be located within existing cleared areas; Implement erosion and sediment control measures; Wash-down machinery and vehicles prior to accessing site to avoid the transmission of weed seed or disease into intact areas of native vegetation; and Rehabilitate the borehole drilling compound locations with pasture (if undertaken on agricultural land) or local native species after the cessation of gas drainage to replace any cleared native vegetation. 6.8 TRAFFIC MANAGEMENT STRATEGIES Traffic to and from the sites is managed to ensure minimal impacts on local residents and to maintain road safety. The following mitigation strategies are implemented: During the construction phase, warning signs will be erected along access points to each property; Development of Journey Management Plans to highlight appropriate controls required for moving of the drill rigs from one borehole location to the next; A Traffic Management Plan is prepared prior to the commencement of any construction works, if required. This plan guides the appropriate controls required for the day-to-day movements of employee s vehicles and associated construction traffic; and Residents are advised prior to the commencement of works and prior to any related disruptions to local traffic. 6.9 WASTE MANAGEMENT STRATEGIES Small amounts of waste are likely to be generated as a result of MSGM. All wastes are removed from site for appropriate disposal. Spoil generated from borehole drilling is reused at the West Cliff Emplacement or for onsite borehole rehabilitation. A Waste Management Plan is prepared as part of the Construction Environmental Management Plan, for both the initial construction and the de-commissioning works. The Plan is developed in accordance with South32/IC s Policies and standard operating procedures. Wastes are removed offsite and recycled or disposed of at a suitable licensed waste management facility Rev 4.1 Page 23

28 6.10 CULTURAL HERITAGE MANAGEMENT STRATEGIES To ensure projects do not have any significant impacts on Aboriginal cultural heritage IC implements the following mitigation measures: Archaeological sites are avoided wherever possible. If within 100m of construction activities, archaeological sites are fenced prior to construction using protective barriers, and all site personnel are notified of the importance of avoiding archaeological sites. If the archaeological sites cannot be avoided then an Aboriginal Cultural Heritage Management Plan (ACHMP) is developed and implemented to facilitate the management of these sites. The ACHMP will also apply to any additional heritage sites uncovered during the project. In the case of skeletal remains the following process is implemented: o All work will stop immediately; o The find will be reported to police; o Aboriginal stakeholders will be notified of the find, in consultation with police; o NSW OEH will be notified of the find; o If the skeletal remains are of Aboriginal ancestral origin an appropriate management strategy will be developed in consultation with Aboriginal stakeholders; o The find will be recorded in accordance with the National Parks and Wildlife Act 1974 (NSW) and the NSW NPWS Aboriginal Cultural Heritage Standards and Guidelines Kit; if required; and o The ACHMP will be updated to include newly discovered Aboriginal ancestral remains VISUAL IMPACT MANAGEMENT STRATEGIES Surface gas drainage during the operational phase generally has minimal visual impact primarily due to the locations being away from sensitive receivers, interim drill pad rehabilitation and the small size of infrastructure. During drilling operations, noise barriers are used to mitigate noise and visibility impacts. Noise barriers are higher than the noisy equipment during the 6-12 week drilling process Well head control sleds and noise walls are painted green to minimise visual impacts. IC will consult with residents prior to the commencement of gas drainage construction activities. This consultation will address the visual aspects of the works during both the construction and operational phases. Any additional mitigation measures required will be planned and implemented in consultation with the relevant resident/s PUBLIC SAFETY Comprehensive safety management plans are prepared for members of the public and the workforce. Journey Management Plans are implemented to ensure safe and efficient transport associated with the Project. Traffic black spots are identified and avoided where possible. Where necessary, direct traffic control is implemented to safely enter / exit public roads from off-road areas. Where traffic control is needed, this is undertaken by qualified and experienced traffic control contractors in accordance with relevant approvals from Roads and Maritime Services or Council. Drilling sites are primarily located on private land, much of which is owned by IC. Only authorised personnel are permitted to enter the property. During borehole construction, the Rev 4.1 Page 24

29 sites are temporally fenced and safety management signs erected. Boreholes are constructed by appropriately licensed and experienced drilling contractors using fit for purpose equipment and techniques. Gas monitoring is undertaken during drilling. All persons entering the project are inducted to the site or are accompanied by relevant IC or contractor personnel, and wear appropriate Personal Protective Equipment. During gas drainage, each boreholes is managed by a wellhead management system that controls flow from the borehole. Flow from the borehole is continuously monitored so that any incident can be responded to immediately. This can include a remote shutdown of the well. Wellhead instrumentation is secured in a locked colourbond compound. Relevant safety signage is displayed at each wellhead. NSW Fire and Rescue and the NSW Rural Fire Service have been briefed on the location and function of MSGM activities Rev 4.1 Page 25

30 7 REFERENCES Cardno Eppell Olsen (2012) Ventilation Shaft No.6 Project Traffic Impact Assessment. Prepared for BHP Billiton Illawarra Coal. Department of Environment and Climate Change NSW (2009). Interim Construction Noise Guidelines. Department of Environment and Climate Change NSW (2008). Managing Urban Stormwater: Soils and Construction Manual. Geoterra (2011) Appin Mine Surface Gas Extraction Groundwater Assessment Niche (2013) Appin Area 7 Lonwall Surface Gas Drainage Works and Operations Terrestrial Flora and Fauna Assessment. Niche (2013) Appin Area 7 Lonwall Surface Gas Drainage Works and Operations Aboriginal and Non-Aborigianl Due Diligence Assessment. NSW Department of Primary Industries (2012) NSW Aquifer Interference Policy. Published by Department of Trade and Investment, Regional Infrastructure and Services. NSW Trade & Investment (2012) NSW Code of Practice for Coal Seam Gas Well Integrity. Published by Department of Trade and Investment, Regional Infrastructure and Services. NSW Trade & Investment (2012) EDG01 Borehole sealing requirements on Land: Coal Exploration. Published by Department of Trade and Investment, Regional Infrastructure and Services. PAE Holmes (2009) Air Quality Impact Assessment: Appin Mine Area 7 Goaf Gas Drainage Project. Undertaken on behalf of Cardno. PAE Holmes (2011) Air Quality Impact Assessment: Appin Gas Drainage. Prepared for BHP Billiton Illawarra Coal. Wilkinson Murray (2013) Bulli Seam Operations Gas Drainage Noise Impact Assessment. Undertaken on behalf of BHP Billiton Illawarra Coal Rev 4.1 Page 26

31 ATTACHMENT 1. INDICATIVE LAYOUT FOR APPIN EAST FLARES Indicative location of flare units planned for installation at the Appin East gas drainage facility.note that in the future further flare units may be installed adjacent to the two indicated Rev 4.1 Page 27