RASP MINE, BROKEN HILL, NSW. Submitted to: Broken Hill Operations Pty Ltd Rasp Mine 130 Eyre Street Broken Hill NSW 2880

Transcription

1 RASP MINE, BROKEN HILL, NSW SITE WATER MANAGEMENT PLAN Submitted to: Broken Hill Operations Pty Ltd Rasp Mine 130 Eyre Street Broken Hill NSW 2880 REPORT Report Number R-Rev11 Distribution: 1 Copy - Broken Hill Operations Pty Ltd 1 Copy - Golder Associates Pty Ltd

2 Table of Contents 1.0 INTRODUCTION STATUTORY REQUIREMENTS Local Government Act State Government Planning Project Approval Environmental Conditions Environmental Protection Licence Protection of the Environment Operations Act SITE DESCRIPTION WATER STORAGE MANAGEMENT FOR MINE WATER Proposed Mine Operations Processing Plant Water Management Shaft 7 and Underground Mine Workings Backfill Plant Sediment Pond OBJECTIVES SURFACE WATER MANAGEMENT GOALS LOCAL CLIMATE FOR BROKEN HILL Mean Monthly Rainfall and Temperature Average Annual Evaporation Design Rainfall Data RAINFALL EXCESS ESTIMATION PROPOSED DRAINAGE LAYOUT CATCHMENT RUNOFF AND SEDIMENT MANAGEMENT PLAN Runoff and Sediment Storages Maintenance Program for the Drainage and Erosion Control Network Erosion Maintenance on Batter Slopes Processing Plant and Railway Siding Catchment Storage Requirements Catchment 1A, 1, 3, 4 and Catchment 8, 9A and 9B Catchment 2, 5, 11A, 11B, 12, 13A and 13B Report No R-Rev11 i

3 Catchment 7, 10 and Catchment 15, 16, 17, 18 (partial), 20B and 20C Catchment 37 (Partial), 38, 38A, 40, 41 and Catchment 39, 39A, 42A, 42B and Horwood Dam Catchment 18 (partial), 19, 20A, 21A, 21B, 22, 26 and TSF Catchment 23, 24, 25A, 25B and Kintore Pit Catchment 27, 28, 29 and Catchment 32, 34, 36, 37 (Partial) and BHP Pit Catchment 30, 31, 46 and Catchment 33, 35, 43 and Blackwood Pit Catchment 44A, 44B and Rail Siding Facility Catchment 48 and Peak Flow Estimation GROUNDWATER MONITORING PROGRAM Introduction Program to Monitor Seepage Movement GW01 and GW02 Located Downstream of Mt Hebbard GW03, GW04, GW05, GW06 GW07, GW08 and GW09 Located Adjacent to TSF GW10 Located Downstream of Horwood Dam GW11 and GW12 Located Adjacent to Blackwood Pit GW13, GW14 and GW15 Located Adjacent to S44, S31-1 and S GW16 Located Adjacent to S Water from Mine Dewatering Eyre Street Dam Seepage Groundwater Quality Parameters Baseline Chemical Properties of Groundwater Selected Groundwater Quality Monitoring Parameters Contingency Measure in the Event of an Identified Unacceptable Impact Groundwater Perched Groundwater SURFACE WATER MONITORING Monitoring Program for Creeks and Other Waterbodies Monitoring Program for Stormwater Ponds Report No R-Rev11 ii

4 12.3 Monitoring Program for Horwood Dam Selected Surface Water Quality Monitoring Parameters Contingency Measures WATER BALANCE Introduction Water Sources Water Demand and Use On-Site WATER QUALITY PROTECTION Chemical Spill Management Chemical Storage Facilities Vehicle Washing Facilities REPORTING AND REVIEW Reporting Groundwater or Surface Water Incidents Internal External Complaints Management Erosion and Sediment Transportation Reporting Regular Reporting Weekly Head of Departments Meeting Rasp Mine Website Annual Return and Annual Environment Management Report Annual DP&I Report Auditing and Review Site Water Management Plan Review REFERENCES Report No R-Rev11 iii

5 TABLES Table 1: Project Approval Conditions... 3 Table 2: Rainfall for Various Design Events Table 3: Design Rainfall Excess for 100 Year Event Table 4: Catchment Details Table 5: Storage Requirements Table 6: Horwood Dam Estimated Storage Capacity Table 7: Peak Flow Estimation applying the Rational Method and Bransby Williams Formula Table 8: Location and Function of Mine Dewatering Samples and Groundwater Monitoring Boreholes Table 9: Groundwater Analytical Suite Table 10: Groundwater Analytical Suite GRAPHS Graph 1: Mean Monthly Rainfall and Temperature for Broken Hill Graph 2: Mean Monthly Evaporation for Broken Hill FIGURES Figure 1: Overall Catchment Areas Site Plan Figure 2: Catchment Area Layout Plan South Western Catchments Figure 3: Catchment Area Layout Plan North Western Catchments Figure 4: Catchment Area Layout Plan North Eastern Catchments Figure 5: Catchment Area Layout Plan Southern Catchments Figure 6: Catchment Area Layout Plan South Eastern Catchments Figure 7: Horwood Dam Storage Areas Figure 8: Proposed Groundwater Monitoring Bore Locations APPENDICES APPENDIX A Australian Water Quality Centre Analytical Report 31/08/2011 Amdel Ltd Analytical Report 24/05/2007 APPENDIX B Rasp Mine Water Management Strategy Report No R-Rev11 iv

6 1.0 INTRODUCTION Broken Hill Operations Pty Ltd (BHOP) commissioned Golder Associates Pty Ltd (Golder) in November 2009 to prepare a Concept Surface Water Management Plan (CSWMP) for the proposed mining operations at the Rasp Mine located on Consolidated Mine Lease 7 (CML7) in Broken Hill, NSW. The purpose of the CSWMP was to identify stormwater management measures that were required on the mine site to facilitate Project operational and environmental objectives, primarily to: Prevent discharge of potentially contaminated surface waters from active mine areas off-site. Minimise disruption to the mining activities and provide a safe working environment. Identify erosion and sediment control measures for the surface areas of CML7 which fall under the responsibility of BHOP. BHOP proposes to extend the areas for underground mining to include the Western Mineralisation, Centenary Mineralisation and additional Main Lode Pillars, expand mining production to 750,000 tpa, which includes a processing plant and rail siding for concentrate despatch. The CSWMP was to support the Environment Assessment (EA) required as part of the application by BHOP for Project Approval of these works under Part 3A of the Environmental Planning and Assessment Act 1979 (EP&A Act) for expansion of operations at its Rasp Mine. There have been several iterations of the CSWMP as part of this process with a final draft submitted to the then Department of Planning (DoP) with the EA Report in July 2010, which was assessed as adequately addressing the Director General s requirements, Reference 07_0018 dated 29 March 2009 from DoP. Subsequent to the submission of the EA, BHOP decided to relocate the processing plant and rail siding to the eastern end of CML7. This required the formulation and submission of a Preferred Project Report (PPR) detailing these changes and providing additional assessment on any new / changed environmental impacts. In September 2010 the CSWMP was updated to address some of these changes and submitted with the PPR. However, until detailed design of the processing plant and rail siding was completed the CSWMP could not be finalised for these areas of the site. It was agreed with the DoP that once detailed design was completed an updated version of the CSWMP would be provided. BHOP received Project Approval on 31 January This Approval outlined a number of conditions some of which pertained to water management (Table 1). To address these new requirements the CSWMP was changed to a Site Water Management Plan (SWMP) and a draft was submitted to the DoP in June Detailed design for the processing plant and rail siding was still incomplete at that time it was agreed that a final SWMP would be submitted when these designs were completed. At this time Golder undertook a review of the SWMP and found some discrepancies in catchment boundaries, storage areas and runoff calculations for individual catchments and updated the document accordingly. The water management strategies were also updated to reflect the water management works that were being carried out on site. Due to the delay in completing the detailed design BHOP obtained an extension to the submission for the SWMP. A Site Water Management Plan (SWMP) (ref L-Rev6 dated November 2011) encompassed responses to the relevant planning conditions as outlined in the Project Approval, and included a layout of the proposed railway siding areas, the new plant layout and drainage details of the lease area to the south west of the mine area. The SWMP also included a groundwater monitoring programme, sediment control plan, surface water monitoring and maintenance plan, a water balance and communication plan. EPA carried out reviews of the earlier versions of the Rasp SWMP. Presented in this document (ref L-Rev11 dated April 2012) includes the recommended amendments to that SWMP based on EPA review and comments. Report No R-Rev11 1

7 2.0 STATUTORY REQUIREMENTS 2.1 Local Government Act 1993 Section 36M of the Local Government Act 1993 (LGA) pertains to the management of community land categorised as a watercourse. The Act States: The core objectives for management of community land categorised as a watercourse are: a) to manage watercourses so as to protect the biodiversity and ecological values of the instream environment, particularly in relation to water quality and water flows, and b) to manage watercourses so as to protect the riparian environment, particularly in relation to riparian vegetation and habitats and bank stability, and c) to restore degraded watercourses, and d) to promote community education, and community access to and use of the watercourse, without compromising the other core objectives of the category. Section 125 of the LGA relates to the council s authority when responding to public nuisances, Section 125 states: A council may abate a public nuisance or order a person responsible for a public nuisance to abate it. Under the aforementioned sections of the LGA, the council are obliged to environmentally protect watercourses and manage public nuisance offences. Consequently, BHOP intends to retain runoff from the mine area up to a 1 in 100 year recurrence interval rainfall event where practical. 2.2 State Government Planning Project Approval Environmental Conditions On 31 January 2011 the Minister for the then Department of Planning issued a Project Approval, pursuant to Section 75J of the Environmental Planning and Assessment Act 1979 for Rasp Mine. The Project Approval was subject to conditions a number of which relating to water management, Schedule 3 Condition 23. Table 1 outlines these requirements and provides a reference to the sections in the SWMP where these are addressed. Report No R-Rev11 2

8 Table 1: Project Approval Conditions Planning Schedule Number Planning Condition Number Planning Condition Addressed in SWMP Section The Proponent shall prepare and implement a Water Management Plan for the project to the satisfaction of the Director-General. This plan must be consistent with the Stormwater Management Plan presented as Annexure K to the EA. Incorporate any changes to reflect the final detailed design of the project, and be prepared in consultation with DECCW, NOW and I&I NSW. The plan must: be submitted to the Director- General for approval by the end of June 2011, and must include: 3 23 (a) 3 23 (b) 3 (c) A Site Water Balance which must: Include details of Sources and security of water supply Water use on site Water management on site Any off-site water transfers Investigate and implement all reasonable and feasible measures to minimise water used by the project An Erosion and Sediment Control Plan, which must: identify activities that could cause soil erosion, generate sediment or affect flooding describe measures to minimise soil erosion and the potential for transport of sediment to downstream water, and manage flood risk describe the location, function and capacity of erosion and sediment control structures and flood management structures; and describe what measure would be implemented to maintain the structures over time A Surface Water Management Plan, which must include: detailed baseline data on surface water flows and quality in creeks and other waterbodies that could potentially be affected by the project; surface water and stream health impact assessment criteria including trigger levels for investigating any potentially adverse surface water impacts 13.2 Appendix B 13.3 Appendix B 13.3 Appendix B 13.2 Appendix B 13.3 Appendix B Report No R-Rev11 3

9 Planning Schedule Number Planning Condition Number Planning Condition Addressed in SWMP Section program to monitor and assess: Surface water flows and quality; 12.1 Impacts on water users 12.1 Stream health; and 12.1 Channel stability 12.1 A Groundwater Monitoring Program, which must : Provide a program to monitor seepage movement within and adjacent to the tailings storage facility; Include details of parameters and pollutants to be monitored for: Water from mine dewatering 11.2, , Groundwater locations to the east of TSF (d) Surface water represented by Horwood Dam Water captured by the toe drains of the tailings storage facility 12.2, , Water seepage from the tailings storage facility; and The background local groundwater system 11.1 Outline performance parameters against monitoring data will be compared to determine whether seepage is occurring, and whether an unacceptable impact on local groundwater may be occurring; Include details of contingency measure to be implemented in the event that an unacceptable impact is identified Appendix A Requirements for management plans as outlined in Schedule 4 Condition 2 are incorporated throughout the SWMP where applicable. Report No R-Rev11 4

10 2.3 Environmental Protection Licence The then Department of Environment, Climate Change and Water (DECCW) issued Environmental Protection Licence No for the Rasp Mine. The DECCW are currently undergoing a review of this Licence to correspond to Project Approval. Condition L1.1 of the Licence, dated 31 January 2011 pertains to pollution of waters and states: Except as may be expressly provided in any other condition of this licence, the licensee must comply with section 120 of the Protection of the Environment Operations Act To comply with the above Licence condition Rasp Mine must not allow pollution of any waters. The drainage design philosophy at the Rasp Mine is to prevent discharge of surface waters from active mine areas off-site. 2.4 Protection of the Environment Operations Act 1997 The Protection of the Environment Act 1997 (POEO Act) is the governing environment protection legislation in NSW. The POEO Act repealed the Clean Waters Act 1970 with effect from 1 July Under the POEO Act Section 120 and the implementing EP Regulation Division 4.2, it is against the law to directly pollute, cause pollution or permit pollution of waters. EP Licence No reflects the conditions of the POEO Act with regards to surface water management. Report No R-Rev11 5

11 3.0 SITE DESCRIPTION The Rasp Mine is located on CML7 within the Broken Hill urban area and is bounded by Menindee Road to the north east, Holten Drive and Eyre Street to the south east, Silver City Highway (South Road) to the south west and Crystal Street to the north west. Mining activity has been carried out on site for over 125 years and the entire site has been disturbed with little or no remnant native vegetation. A mine site plan is provided in Figure 1, which details the location of catchment areas, the existing and proposed drainage layouts and the mine lease exclusion areas. The mine is located at a high point in the regional topography and is a prominent feature in the City of Broken Hill. Most of the site is raised from the adjoining area in the form of an extensive mound, formed from waste rock and tailings storages. Elevations throughout the site are estimated based on an aerial survey carried out in January Site elevations vary from approximately 356 m AHD at the parking area for the Broken Earth Café and Miners Memorial to approximately 216 m AHD at the base of Kintore Pit. Mount Hebbard is approximately 31 m higher than ground elevations at the CML7 boundary adjacent to Eyre Street, while the Miners Memorial is elevated approximately 43 m above Crystal Street level. The total area of CML7 is approximately ha. There are several surface exclusion zones within CML7; these include rehabilitated areas and areas with no or limited surface rights. These exclusion zones are approximately ha and are shown in Figure 1. BHOP is not responsible for surface water management in these exclusion zones and as such this SWMP does not include management measures in the excluded areas. In addition there are a number of other occupiers conducting businesses within BHOP surface lease area of CML7, these include: The Broken Earth Café. Miners Memorial. Communications tower. Tourist activities at Browns Shaft and Block 10 Lookout. Land and Property Management Authority buildings, unoccupied residences and BHP House (British Flats). Olive plantation. The SWMP has accommodated the occupiers which contribute runoff to the proposed drainage features or are within the active mine site. Some of these occupiers are located outside of the active mine site on unaffected areas and are not accounted for in the SWMP. These occupiers include: Tourist activities at Browns Shaft (Junction Mine). Land and Property Management Authority buildings, residences and BHP House (British Flats). Olive plantation. The design 100 year rainfall runoff event from the active mine area is to be contained within the site. Due to topography and drainage patterns, parts of the exclusion zones, areas outside of the CML7 and parts of the rehabilitated areas or areas unaffected by mining activities, contribute runoff to the active mine area. The runoff from these areas are included in the active mine area, bringing the total area for runoff containment to 195 ha. For events that are rarer than the 100 year event, the runoff from the site would overflow to drainage systems surrounding the mine. Report No R-Rev11 6

12 4.0 WATER STORAGE MANAGEMENT FOR MINE WATER 4.1 Proposed Mine Operations The proposed mining operations in CML7 comprise underground mining of the Western and Centenary Mineralisation and mining of the Main Lode Pillars. Underground mining will be accessed via a portal and decline from the base of the Kintore Pit. Ore will be transferred by trucks to the ROM pad. It is also proposed to construct and operate a mineral processing plant to produce zinc and lead concentrates. A tailing storage facility (TSF) is to be developed in Blackwood Pit and a rail siding installed adjacent to the current ARTC track at Menindee Road to the north east of CML7. The processing plant will be located to the south east of Blackwood Pit. The layout of the proposed operations, including roads are shown in figures attached to this Plan. 4.2 Processing Plant Water Management It is proposed that runoff from the process facility be directed to a first flush Plant Water Pond in catchment 42B, with overflows into a second pond (Plant Event Pond) located at the toe of the embankment within this catchment. Both ponds will be lined facilities. Blackwood Pit will retain the tailings from the processing plant, and supernatant water from this storage facility will be transferred direct to a lined pond at the plant (Plant Water Pond) located in, but not part of, catchment 42B for subsequent reuse in the processing plant. These ponds allow for the storage of supernatant water from Blackwood Pit, plant upsets and a 1: hour rainfall event. Any overflow from the Plant Event Pond (in excess of a 1:100 year rainfall event) is directed to Horwood Dam. 4.3 Shaft 7 and Underground Mine Workings The storage area S22 is a large gully with a storage capacity in excess of 40,000 m³. The gully is to be used as catchment storage for runoff from surrounding catchments including TSF 1. It will also be used for the separate storage and settling of water from the operating underground mine workings and the Shaft 7. This water will be reused for mining activities underground and will be treated and used in the processing plant. The area of S22 will be divided into 5 compartments with the northern and southern ends available for surface water runoff (refer to Figure 3). For a 1 in 100 year ARI rainfall event, runoff into the northern compartment of the gully will be from TSF 1 of approximately 10,304 m³. The runoff into the southern compartment of the gully will be from catchments 18, 19, 21A, 21B and 22 and will approximate to 10,185 m³. The central three compartments will be lined and will comprise of two settling ponds and a storage pond with installed pumping capacity. The volume of stored water in northern and southern compartments will be kept to a minimum. Any collected stormwater would either be evaporated or added to the central compartments for reuse underground or in the processing plant. 4.4 Backfill Plant Sediment Pond A backfill plant will be located to the south west of the site in catchment 27. This catchment will include a lined backfill plant sediment pond, isolating any potentially contaminated runoff in this area from the general runoff of the site. Report No R-Rev11 7

13 5.0 OBJECTIVES The main objectives of this Plan are to: Prevent discharge of surface waters from active mine areas off-site. Separate runoff from the mine processing plant area and areas of general runoff. Limit disruption to the mining activities and provide a safe working environment. Identify erosion and sediment control measures for the site and outline control measures and a monitoring plan for areas considered susceptible to erosion. Outline a groundwater management program for monitoring flow paths of infiltrated rainwater and groundwater mounding. Provide a site representative water balance. In the development of this Plan the relevant engineering guidelines have been followed for best management practices for water management, as referenced in Chapter 15 of this Plan. Report No R-Rev11 8

14 6.0 SURFACE WATER MANAGEMENT GOALS The existing landform on site and the arid climate conditions provide opportunities to develop a SWMP that satisfies the operational requirements of the mining activity and prevents release of runoff from active areas of the mine site for rainfall events up to the design frequency event. The primary feature of the SWMP is the provision of small ponds/storages, spread throughout the mine site, that temporarily hold surface water runoff. Due to high evaporation rates, this runoff would be expected to evaporate in a relatively short period following rainstorm events. This arrangement retains runoff within the active mine site and allows the suspended particles to settle in the ponds/storages, allowing better management of contaminated sediment on site. A set of goals identified to guide the preparation of this SWMP are described below: Retain runoff from a 1 in 100 year ARI 24 hour rainfall event from the active mine areas. The high evaporation rate would allow retained water to evaporate in a relatively short period. This goal will minimise impact on the downstream environments. Retain runoff locally in small ponds / storages at various locations on the mine site, utilising the existing landform where feasible. This would: Eliminate the need to construct a large storage and avoid hazards associated with large storages. Help in the sedimentation process that would remove suspended solids from the runoff. Minimise erosion potential by eliminating the requirement to carry large discharges to a smaller number of large storages. Provide appropriate spillways for the local ponds to convey flows greater than the 100 year runoff event. Spillways will be set at the 1 in 100 year ARI 24 hour storm event storage level. It is noted that some storage areas have capacity in excess of the 100 year ARI 24 hour storm event. In these cases the installation of a spillway will be set higher than the 100 year ARI storm event storage levels. Use the available capacity of Horwood Dam to contain the 100 year runoff event from various subcatchments that report to this dam. Use the available capacity of Mt Hebbard Gully (S22) to contain runoff from TSF 1, Mt Hebbard (catchment 19) and adjacent catchments to the west, in addition provide storage for mine water settlement ponds including underground mine dewatering, groundwater from Shaft 7 and active TSF decant water. Divert runoff away from Kintore Pit to reduce the flooding risk in the pit and associated potential impact on mining operations (as the portal and decline for the proposed underground operations are located in the base of Kintore Pit). Provide appropriate sediment and erosion control measures on site. Numerous small pondages result in large combined surface area to facilitate settlement of sediment in runoff flows, and facilitate relatively easy and conventional access for application of dust suppressants if required during dry periods. Divert stormwater surface runoff around mining affected water storage facilities. Select proposed locations for the shallow monitoring groundwater bores around key facilities on site. Summarise results of the site water balance model. Address the conditions of the Project Approval. The above goals provide the criteria for the development of the SWMP. Report No R-Rev11 9

15 7.0 LOCAL CLIMATE FOR BROKEN HILL 7.1 Mean Monthly Rainfall and Temperature The local climate is arid with an average annual rainfall of approximately 250 mm. A review of the Bureau of Meteorology (BOM) Patton Street Site climate data for the last 120 years indicates that the mean monthly rainfall varies in a narrow band from 17 to 24 mm during the year. The monthly mean maximum temperature varies from approximately 33 o C in January to 15 o C in July. The following graph shows the monthly variations for rainfall and temperature. Graph 1: Mean Monthly Rainfall and Temperature for Broken Hill Patton Street Gauge - Climate Data Mean Daily Max Temp (degree C) Mean Daily Rainfall (mm) January February March April May June July August September October November December months 7.2 Average Annual Evaporation The average annual evaporation is approximately 2,614 mm. This estimate has been derived from the BOM grid data estimates for the entire Australian continent. The evaporation rate varies from approximately 12 mm/day in December to 4 mm/day in June. The monthly variations for evaporation are presented in Graph 2. Report No R-Rev11 10

16 Graph 2: Mean Monthly Evaporation for Broken Hill Mean Monthly Evaporation (mm) January February M arch April M ay June July August September October November December Evaporation far exceeds the rainfall in the Broken Hill area. The mean monthly evaporation is more than 15 times the mean monthly rainfall in January and approximately 5 times in July. 7.3 Design Rainfall Data The design rainfall data was sourced from the BOM and is presented in Table 2 below. Table 2: Rainfall for Various Design Events DURATION 10 years ARI 1 Rainfall (mm) 20 years ARI 50 years ARI 100 years ARI 30Mins Hr Hrs Hrs Hrs Hrs Hrs Hrs Hrs Note: 1. ARI = Annual Recurrence Interval The data for the 100 year ARI was used in the catchment analysis carried out for the preparation of the SWMP. Report No R-Rev11 11

17 8.0 RAINFALL EXCESS ESTIMATION The proposed drainage concept is based on retaining the runoff volumes from a 1 in 100 year ARI rainfall event from active mine areas. The runoff volumes are dependent on the soil types present on the mine site and their infiltration capacity. High traffic areas or areas subject to other activity that causes compaction of the soils would generally produce greater runoff volumes. While this variation in site soil conditions has been noted at Rasp Mine, in the context of a hydrological analysis and for the purpose of catchment analysis, runoff has been estimated based on historical reports related to runoff analysis of the site. Before runoff can occur, a portion of rainfall is lost to initial absorption by the materials to bring them to field moisture capacity. This rainfall loss is termed as Initial Loss. As the runoff develops, the infiltration occurs during the rainfall event, and is generally a rate per hour related to the permeability of the near surface material. This rainfall loss is termed as Continuing Loss. For design rainfall events such as the 100 year ARI event, the Australian Rainfall and Runoff (AR&R; Engineers Australia, 1987) recommends that an Initial Loss of 15 mm and a Continuing Loss of 4 mm/hr should be adopted for arid zones of New South Wales. However, previous studies by John Miedecke and Partners (October, 1993) have established an initial loss rate varying from 10 to 20 mm and a Continuing Loss rate of 2 mm/hr from the analysis of the December 1992 storm event at the Rasp Mine. That event was close to the 100 year rainfall event. The rainfall loss guidelines provided in AR&R are general in nature and are related to a large area. John Miedecke and Partners (October, 1993) analysed a local storm and derived the rainfall losses based on the observed flood behaviour on site. Although this analysis was not conclusive, it still provides a better estimate than the general guidelines provided by AR&R. Based on the Miedecke analysis the rainfall losses as assessed in the October 1993 report have been adopted i.e. an initial loss of 10mm and a continuing loss of 2mm/hr. The adopted loss rates are deemed to be conservative relative to the AR&R guide and would provide a safety factor for the runoff estimates undertaken for the SWMP. The adopted loss rates were used in conjunction with the design rainfall (Table 2) to derive the rainfall excess or the volume of runoff from each catchment. The estimated rainfall excess for the 100 year event is presented in Table 3. Table 3: Design Rainfall Excess for 100 Year Event DURATION Rainfall Excess (mm) 30Mins Hr Hrs Hrs Hrs 64 12Hrs 70 24Hrs 73 48Hrs 62 72Hrs 55 The critical duration for the 100 year event is the one that corresponds to the largest rainfall excess and hence the largest volume of runoff. For the 100 year event, the critical rainfall excess occurs for the 24 hour event and is equal to 73 mm (highlighted in Table 3). Report No R-Rev11 12

18 9.0 PROPOSED DRAINAGE LAYOUT The proposed drainage layout is based on the criteria presented in the previous sections. Provision has also been made to safely discharge a higher intensity event by providing spillways for various storages where appropriate. The locations of spillways are marked on the proposed drainage layout. Based on the runoff management criteria, the mine site was subdivided into small catchments enabling where possible for the runoff from each catchment to be retained within the catchment by providing bunding along some of the catchment boundaries. Where feasible the runoff from some catchments is also diverted to the BHP Pit, while runoff from TSF 1 and surrounding area is directed into S22 (Mt Hebbard Gully). A catchment analysis that provides details of the runoff volumes and areas for various catchments is presented in Table 4 and the attached figures. Table 4: Catchment Details Catchment Number Area Runoff Volume (100 year event) (ha) (m³) ,739 1A , , , , A B ,576 11A B , A ,883 13B , , ,799 20A ,756 20B ,110 20C ,814 21A ,024 21B , ,071 Report No R-Rev11 13

19 Catchment Number Area Runoff Volume (100 year event) (ha) (m³) ,148 25A B , , , , , , , , , , , A ,515 39A , A ,758 42B , ,113 44A ,243 44B , , , ,951 Horwood Dam ,779 Kintore Pit ,810 Little Kintore Pit ,924 BHP Pit ,388 TSF ,304 Blackwood Pit ,633 Report No R-Rev11 14

20 10.0 CATCHMENT RUNOFF AND SEDIMENT MANAGEMENT PLAN The activities which may result in soil erosion, generation of sediment or flooding at the Rasp Mine are mining activity and weather activity (water or wind). Proposed mining activities will primarily consist of underground works with limited stockpiling, transportation activities and maintenance works taking place on the surface of the landscape. The main concern at Rasp Mine is erosion related to weathering and in particular, water runoff. During construction of the processing plant and associated works the risk of erosion during the construction works will be managed in line with accepted good construction practice of using temporary sediment storages and sediment controls, such as hay bales in drains and silt fences, as referenced in the Managing Urban Stormwater: Soils & Construction (Landcom), Managing Urban Stormwater: Source Control (DECC) and Technical Guidelines: Bunding & Spill Management (DECC). The susceptibility to soil erosion, the generation of sediment and flooding as a result of water erosion has been minimised by dividing the site into several smaller catchments, 68 individual catchment areas in total. The catchment layouts generally conform to the existing landform and where practical, storage areas have been provided within the catchment. The majority of catchments have their own storage pond capturing rainfall and sediment from the surrounding area. Where storage areas are not provided within a catchment, due to site restrictions, drainage channels discharge runoff into nearby catchment storage ponds. This design approach limits the potential for the transportation of sediment to downstream waters and manages the risk of flooding within local catchments. The capacity of the required storage ponds and channels to meet the requirements of the 1 in 100 year ARI event is provided in this Plan. BHOP will continue to assess the actual capacity of water storages against this criterion and will carry out de-silting works if required in order to create and maintain the required water storage capacity Runoff and Sediment Storages Existing low areas or depressions in various sub-catchments on site will be utilised as pond storage areas. These areas have developed a layer of fine grain soil particles due to sediment deposition from rainfall events resulting in the storage subgrade having a low to moderate infiltration rate. Where practical the existing sediment layer will not be disturbed. These ponds are expected to accumulate further sediment, which will be monitored by installing sediment depth indicators. When sediment levels reduce the 100 year storage capacity of the pond by 10%, BHOP will desilt the pond of the new sediments to restore the design storage requirement. Where BHOP need to modify existing storages the modification may include rolling the base layer of construction material to reduce the subgrade permeability and therefore the likelihood of significant seepage from the storage. Potential seepage from storage basins within the site is anticipated to seep into the existing mine materials and workings. Monitoring bores located at the perimeter of the site will monitor perched seepage from the storages. Where there are changes in the water quality that may indicate potential adverse seepage impacts, an investigation will be undertaken and actions taken to interrupt current water flows and prevent a recurrence. Actions may include pumping of stored water to a lined facility within the site or lining of the storage facility. Where the water facility is lined, the design criteria will include for a protection layer over the liner to allow for desilting works to take place without risking damage to the liner layer. Access for maintenance vehicles to carry out de-silting works at pond locations will be included as part of the construction of the lined facility Maintenance Program for the Drainage and Erosion Control Network Storage ponds effectively serve as sediment control ponds and limit the movement of sediment throughout and off site. Sediment build-up may occur in ponds after storm events and reduce the capacity of the pond to cater for future rainfall runoff. Regular cleaning of these ponds will occur to maintain the required 100 year ARI water storage for the purpose of surface water management. Report No R-Rev11 15

21 Regular inspection and maintenance of the stormwater management works will be carried out. Due to the low rainfall in this region, inspections of stormwater management works will be carried out on a quarterly basis and after each significant rainstorm event. An action response plan will be developed where repairs are required. Erosion activity within drains and sediment ponds becomes greatest at times of high water flow resulting from a corresponding increase in flow velocity. BHOP will carry out an inspection following rainfall events resulting in 30 mm or more of rain falling in up to 2 hours or 75 mm or more over any 3 consecutive days. Pond storage reduction occurring due to an increase in the thickness of sediment build up and the reduction in pond capacity will be monitored by installing sediment depth indicators at each pond location. As a minimum BHOP will desilt the ponds during winter whenever the storage requirement has been reduced by maximum 10% of the design storage requirement, i.e.: storage capacity is 90% of the design storage requirement. This will prepare the storages for the summer season when the majority of rainfall occurs in Broken Hill. These routine inspections will consist of a visual assessment for erosion, flooding, trash, algal growth or significant sediment build up. A schedule of problem areas will be recorded on an Inspection Check List and referred to by BHOP in performing stormwater management works. Storage capacity will be assessed by viewing sediment depth markers, and volume assessment based on survey data, where appropriate (e.g. after significant de-silting). Periodic re-surveying of the storages may be required where significant de-silting has occurred to establish the revised storage capacity of the storage. When sediment builds up along drains, at storage ponds or in hydraulic structures, it will be removed and disposed of on site. Removed sediment will be disposed in one of the existing large mine pits on site, thereby reducing the likelihood of the sediments being re-mobilised. BHOP will establish an Inspection Check List to ensure the surface water drainage network is systematically inspected. The Inspection Check List will also highlight if there are areas within the drainage networks that are in frequent need of repair and this will allow BHOP to make an informed decision on the need, location, function and capacity of additional erosion or sediment control structures. Where catchments include new facilities intended to store mining related water, stormwater runoff will be diverted around the facilities and impingent rain on the facilities managed as part of the mine related water. The integrity of bunds surrounding storage areas will be assessed and maintained when required Erosion Maintenance on Batter Slopes Erosion and generation of sediment are prone to occur in areas of steep slopes, particularly after intense rainfall events. Construction of further batters, with the exception of slopes constructed in excavations for the processing plant and railway siding area, are not proposed at this stage of the mining operations and therefore the erosion and sediment control measures will mainly consist of managing the existing batters. The majority of the existing batters were constructed during former mining operations and consequently the surfaces of the batters predominantly consist of weathered rock. Batter slopes vary throughout the mining site from 3.5H: 1V north of Horwood Dam, 1.5H: 1V east of Horwood Dam, 1.4H: 1V on the south side of the existing tailings facility and 1.6H: 1V west of Little Kintore Pit. It is not practical to reshape the slopes, as most of the slopes are on the mining boundary, relatively steep and comprise predominantly large rock particles. The process of erosion over the years since the slopes were formed has removed most of the finer materials and the existing surface now comprises relatively large and coarse particles resulting in self armoured surface with limited erosion potential. As a control measure to limit further erosion of the batters it is proposed to divert surface water from the batter slopes by shaping the top area of the landform to allow surface water to drain away from the crest of the slopes. In locations where shaping of the batter crest is not possible, open drainage channels will be constructed to divert surface water away from the batter face. Report No R-Rev11 16

22 Most slopes include a stormwater collection drain along the toe. These drains direct flow to ponds that will collect and settle out sediments as part of the stormwater collection system. Some of the drains are large swales that will form part of flow detention system and these drains will collect sediment. Proposed maintenance works are scheduled to be carried out periodically on the batters to collect and dispose of loose material, which may be washed down the side slopes during severe storm events. The collected eroded material will be disposed of on site Processing Plant and Railway Siding The processing plant will be located to the south east of Blackwood Pit. Any overflows or spills from the processing plant will be captured by the containment provided as part of the plant layout design and report to the Plant Water Pond and Plant Event Pond. The ROM Pad, where mined material will be stockpiled, will be bunded and is included in the runoff for catchments 39 and 39A. The runoff from these areas will report to the Plant Water Pond and Plant Event Pond, which will be operated and managed as combined sediment and plant stormwater ponds. The railway siding located at the north eastern end of the site includes a toe drain along the edge of the Rail loading area where an existing slope will be reshaped to construct the rail siding. The condition of the excavated slope will be assessed during construction to decide on the appropriate erosion protection of the surface, if any. The toe drain will direct any runoff and sediment to the storage S44, where any eroded material will settle out and be managed similar to the other sediment and water storages on the site. Slopes formed as part of the construction works of the processing plant and rail siding will be subject to a monitoring program, to assess the need for armouring of the slopes, depending on the material exposed on the surface of the slopes and the final geometry of the slopes. Armouring of the slopes will include select waste rock capping over new mounds and on slopes. Site inspections will continue to identify requirements for repairs Catchment Storage Requirements The following sections provide details of the catchments with regard to runoff management, and actions to enhance management of runoff in line with the proposed mining activities. In addition, where existing storage areas exist, such as S22 and Horwood Dam, catchments have been combined to improve the water management efficiencies of the site. It is noted that site work and natural erosion and sediment activity occurring in the smaller existing depressions onsite over the past 12 years has not been captured by the January 2000 Survey. Therefore an assessment of levels and the required reshaping to achieve required storage capacities in the ponds will be assessed based on site inspections and surveys as part of the implementation of this Plan. BHOP will keep As-Built records of the constructed and de-silted ponds onsite and establish markers at each storage area indicating sediment depth. Table 5 summarises the surface water storage for various catchments. The proposed management measures may be modified on site for ease of construction based on topography and site conditions, while maintaining the integrity of the proposed drainage and storage concepts. Note that references on report figures are relative to magnetic north, and not in reference to the mine grid. Report No R-Rev11 17

23 Table 5: Storage Requirements Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N West Drain 1 3,739 N/A N/A N/A N N S1A 1A, 3, 4 4,017 16, N Y Spillway (Y/N) Comment Existing storage channel; BHOP will assess if desilting works are required. The West Drain will act as an attenuation drain for the 100 year ARI rainfall event. Overflows from the West Drain for events greater than the 100 year ARI event will be diverted through an existing box culvert and to storage area S1A. Catchment forms storage. Direct runoff from catchments 3 and 4 report to the existing box culvert crossing under the road before discharging to S1A. Overflows from catchment 1 (West Drain) for events greater than the 100 year ARI event also report through the box culvert under South Road to storage area S1A. Underground water storage tanks south of catchment 7 pump sump water into the existing drain in catchment 4 where flow is then diverted into S1A. Storage S1A has the capacity to retain approximately the 1:500 year storm event, with overflows from greater storm events to potentially report off-site. Report No R-Rev11 18

24 Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N Spillway (Y/N) Comment S2 2 5,003 5, N Y S5 5 1,514 2, N Y S6 6 1,103 2, N Y S N Y S9B-1, S9B- 2 9A, 9B 880 1, N Y S11A 11A 994 3, N Y Existing storage S2 is to retain the 100 year storm event with overflows for greater than the 100 year ARI to discharge to the drainage channel (via a spillway) located in catchment 13A. Existing storage BHOP will assess if desilting works are required. BHOP will assess storage area and verify if it can retain the 100 year storm event. Overflow path to catchment 13B drainage channel. Storage to retain 100 year storm event. Overflow path to S1A through catchment 4 for storm events greater than the 100 year ARI. Re-grading works will be carried out at the low point in catchment 8 to increase storage capacity of S8 to meet the 100 year ARI rainfall event. Overflows from S8 for rainfall events greater than the 100 year ARI report to S9B-2 Existing storages, BHOP will carry out desilting and repair work if necessary to increase the capacity of the ponds to meet the 100 year ARI storm event. Overflow to street stormwater system. Existing pond, no work required to increase capacity of pond. Overflows report to Storage S12. Report No R-Rev11 19

25 Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N Spillway (Y/N) Comment S11B 11B 1,685 3, N Y S , N Y S13A 13A 4,883 7, N Y S13B 13B 478 2, N Y S14 7,10, 14 7,813 3, N Y S17-1, S17-2, S ,16,17 and part of 18, 20B 4,265 7, N Y Existing pond, no work required to increase capacity of pond. Overflows in excess of the 100 year ARI storm event to be diverted into S12 and eventually reports to Horwood Dam (via storage areas S14, S17-1, S17-2 and S17-3). Existing pond, no work required. Overflow reports to drainage channel located in catchment 13A and eventually to Horwood Dam. Overflows from S13A discharge through a proposed spillway into an existing drainage channel with overflows reporting to storage areas S14, S17-1, S17-2 and S17-3 and eventually to Horwood Dam. Pond will be designed to contain the 100 year ARI rainfall event. Overflow reports to drainage channel in catchment 14 and are directed to storage pond S14 and eventually to Horwood Dam. S14 receives direct runoff from catchments 7, 10 and 14. Overflow for events greater than the 100 year ARI report to catchment 17. Three existing storage areas located either side of existing tank. Storage Areas S17-1 and S17-2 are connected by existing pipes. BHOP will carry out an assessment of the Report No R-Rev11 20

26 Storage or Attenuation Drainage Channel S18 Plant Water Pond and Plant Event Pond Reporting Catchments Part of catchment 18 Runoff Volume for storage (m 3 ) 389 Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N N Y 39, 39A 3,785 2, Y Y Spillway (Y/N) Comment capacity of the existing storage areas and if required will carry out de-silting works to increase the capacity of the pond. Pumping of stormwater is required from S17-3 to the high point on the drainage channel located at the boundary between catchments 20B and 20C. Overflows in the proposed drainage channel will then flow under gravity to Horwood dam. An existing pond that receives partial runoff from catchment 18. This pond will capture part of the 1 in 100 year ARI storm event with overflows reporting to S17-3. Will receive runoff from Processing Plant Site and TSF decant water pumped from tailings deposition in Blackwood Pit. Water in the Plant Water Pond will be reused in the plant and augmented by water from the lined mine water ponds at Mt Hebbard Gully (S22). Overflows from the Plant Water Pond will discharge through a proposed mine water transfer pipe to the Plant Event Pond located in catchment 42B where any overflows are directed to Horwood Dam. Report No R-Rev11 21

27 Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N Spillway (Y/N) Comment S22 Northwestern drain 18 (partial), 19, 20A, 21A, 21B, 22 and TSF 1 20,489 5, Y Mine water compartments only N/A N/A N/A N OUTLET S25A 25A 908 1, N Y S25B 24, 25B 2,757 2, N N N Existing storage area. In addition to providing storage for the 100 year ARI rainfall event from catchments 18 (partial), 19, 20A, 21A, 21B, 22 and TSF 1, S22 will also be used for the storage and settling of water from the operating underground mine workings, TSF decant water and groundwater from Shaft 7. Mine dewatering activity and TSF decant water will occupy 2 storage areas within S22 with Shaft 7 groundwater requiring one storage area. No overflow path is proposed as the capacity of this gully is in excess of 40,000m 3. Existing storage channel located within exclusion and rehabilitated zone will receive runoff from the embankment located in catchment 23. BHOP are not responsible for controlling drainage works inside of the Exclusion Zones or Rehabilitated Zones. Storage areas will be sized to contain the 100 year ARI. Overflows from S25A will be diverted away from the Vent Shaft area and will report to S25B. Storage areas will be sized to contain the 100 year ARI. Overflows from S25B will spread over the floor of catchment 25B. Report No R-Rev11 22

28 Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N Spillway (Y/N) Comment S ,224 1, N Y S28 S , 28, 29 and partial 34 30, 31A, 46, 47 4,613 3, N Y 6,761 3, S B 225 1, S35 33, 35 6,092 4, N Y S37 (partial) , N Y N N Y Y S26 to receive runoff from catchment 26. Overflows for events greater than the 100 year ARI report to S22. S28 to receive runoff from catchment 27, 28, 29 and part of catchment 34. Overflow from S28 will flow onto the existing access road and into the existing railway drainage system off-site. BHOP will carry out desilting works to the existing storage area S31-1 to obtain adequate capacity to cater for the 100 year ARI storm event. Overflows from S31-1 report to the existing railway drainage system off-site. Existing pond S31-2, BHOP will assess the capacity of this pond to cater for the 100 year ARI storm event. Overflow from S31-2 report to S31-1. Runoff from catchment 33 flows through existing pipes prior to entering catchment 35. Overflows from S35 for events greater than the 100 year ARI event report to Blackwood Pit. Captures runoff from approximately half of catchment 37. Overflows to drainage channel in catchment 36 and into BHP Pit. The remainder of catchment 37 drains into a Report No R-Rev11 23

29 Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N Spillway (Y/N) Comment proposed drain which discharges to S41. S41 37 (partial), 38, 38A, 40, 41 3,994 1, N Y S42A 42A 2,758 2, N Y S , N Y S44 44A, 44B 3,154 2, Sediment Pond, located in catchment 44B Rail Siding Area N/A N/A N/A N/A N N N Y Runoff from catchments 37 (part of catchment), 38 and 38A are diverted into a proposed drainage channel which will extend along the west side of the Processing Plant, though catchment 40 and discharges into S41. Overflows from S41 discharge into a proposed overflow pipe and into storage area S42A, which eventually discharges to Horwood Dam. Runoff from catchment 42A captured in an existing drainage channel and into S42A. Overflows from S42 report to Horwood Dam. Receives direct runoff from catchment 43. Overflows for storm events greater than the 100 year ARI report to Blackwood Pit BHOP will excavate a new storage area to cater for the 100 year ARI event. Overflow to existing large surface water pit to the north west. BHOP will excavate a water pond to capture runoff from the proposed Rail Siding Area. Overflows from the Sediment Pond will discharge into the Rail Loading Area. Report No R-Rev11 24

30 Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) (m) Lined = Y Unlined = N Spillway (Y/N) Comment S , N Y Drainage Channel catchment ,047 N/A N/A N/A N S ,951 1, N Y not applicable S45 will receive runoff from catchment 45. Overflows for events greater than the 100 year ARI will be diverted into a proposed drainage channel and into S41, which in turn reports to the existing drainage channel in catchment 42A and eventually discharge to Horwood Dam. Catchment 48 is a rehabilitated area within CML7. Runoff from the western part of catchment 48 is to be directed via a drain in a south eastern direction to an existing drainage gully, which flows under the public road to the Olive Grove. Catchment 49 is a rehabilitated area within CML7. Runoff from this catchment is captured in three small detention ponds S49. Overflow from S49 will discharge through an existing spillway in the embankment to the street stormwater drainage system. The retention and management of S49 is currently under investigation with a determination to be made as to retain and expand the system to allow for a 100 year storm event or allow for discharge of stormwater directly to the street stormwater drainage system and close the ponds. Determination and works are planned to be completed by end of Report No R-Rev11 25

31 Storage or Attenuation Drainage Channel Reporting Catchments Runoff Volume for storage (m 3 ) Surface Area of storage (m 2 ) Average Depth of Inundation (m) Maximum Depth of Storage (including 0.3 m freeboard) Lined = Y Unlined = N Spillway (Y/N) Comment (m) Little Kintore Pit Little Kintore Pit 1,924 N/A N/A N/A N N Only direct rainfall onto catchment reports to Little Kintore Pit. Kintore Pit Kintore Pit 9,810 N/A N/A N/A N N Estimation of direct rainfall volume on Kintore Pit for the 100 year storm event. BHP Pit Blackwood Pit Horwood Dam 32, partial 34,36, BHP Pit 9,312 N/A N/A N/A N N Blackwood 9,633 N/A N/A N/A N N 42B, 20C, Horwood Dam 7,663 N/A N/A N/A N Y Receives runoff from catchments without storage areas and overflows from S37. Blackwood pit receives overflows from S35 (when in excess of a 100 year storm event) and S43. Catchment 20C and 42B reports runoff directly to Horwood Dam with overflows from S14, S17-1, S17-2, S17-3, S41, S42A, S45 report to Horwood Dam. Storage can retain 100 year storm event. However, spillway required to provide controlled discharge during extreme storm events well in excess of 100 year ARI (up to 4 times the 100 year ARI, which is equivalent to more than the 1 in 1000 year rainfall event). Note: Lined ponds are facilities where the pond is to be lined to limit seepage for environmental purposes. The liner may comprise of compacted clay rich soils or a geosynthetic liner. Report No R-Rev11 26

32 Catchment 1A, 1, 3, 4 and 6 Catchment 1 consists of the area that contains the slope along the western raised landform (Figure 2). The runoff from this area is captured in an existing drain (West Drain) at the base of the raised landform. Flow through the West Drain is directed through a box culvert under the South Road as shown in Figure 2 to storage S1A, which has the capacity to retain runoff for approximately the 1 in 500 year ARI from catchments 1A, 1, 3 and 4. A spillway from S1A will allow water to leave the site during extreme rainfall events. Catchments 3 and 4 (refer to Figure 5) are minor catchments in the western corner of the site. These catchments will not be disturbed by mining activities and runoff from this area will be diverted to the West Drain. Runoff from catchment 6 will flow into proposed pond (S6). The storage will be sized to retain the 100 year storm event with a proposed overflow channel reporting runoff in excess of the 100 year ARI storm event through catchment 4 and to S1A. A bund is required adjacent to the existing track to increase the storage capacity of S6. Some surface shaping may be required. BHOP has installed underground tanks at the south boundary of the site adjacent to catchment 4. It is proposed that the sumps from these tanks are pumped to over the ridge high point in catchment 4 and into the drainage channel, which diverts flow into S1A. These underground tanks are for water storage only and therefore may be pumped directly into storage S1A. It is not anticipated that volume of water being pumped from the underground tanks will impact significantly on the storage capacity of S1A. BHOP will carry out the following works: Clean and check integrity of West Drain along the toe of the western raised landform. Construct drain from West Drain through existing culverts to catchment 1A. Grade the areas to provide storage in catchment 6 for the 100 year storm event and construct a spillway and overflow channel that links S6 to catchment 4. Construct a bund along the access track adjacent to storage area S Catchment 8, 9A and 9B Catchments 8, 9A and 9B are located at the south-eastern corner of the site (Figure 5). Catchment 8 has an existing low lying area and it is proposed that overflows from S8 discharge through an open channel or pipe to storage area S9B-2. Catchment 9 is divided into two areas (9A and 9B) and currently provides water storage in small depressions. An assessment of the capacity of the current water storage areas will be carried out and BHOP will undertake desilting works to meet the retention requirements as outlined in Table 5. Runoff in this area is currently maintained by bundling along the boundary of the Lease. The current condition of this bunding will be reviewed and repair work carried out if required. BHOP will carry out the following works: Regrade catchment 8 at the low point to increase storage capacity of S8 to meet the 100 year ARI storm event. Check capacity of current storages S9B-1 and S9B-2 against storage requirements for the 100 year ARI rainfall event (Table 5) and de-silt if necessary. Check integrity of boundary bunding and repair if required. Report No R-Rev11 27

33 Catchment 2, 5, 11A, 11B, 12, 13A and 13B The runoff in catchment 2 will be diverted to a storage pond (S2) on the north western side of the catchment (Figure 2). This area currently provides storage, however we are proposing that S2 is relocated away from the crest of the embankment as part of the erosion management strategy to a more central location with catchment 2. This catchment should not be disturbed by mining activities. The storage pond S2 is sized to retain the 100 year storm event with overflows from S2 diverting into the existing drainage channel in catchment 13A and to S14. Runoff from catchment 5 will flow into an existing storage pond S5 (Figure 5). The storage volume of this pond will be checked against the catchment runoff for the 100 year ARI rainfall event (Table 5) and desilting will be carried out if necessary. Overflows from S5 will report to the drainage channel located in catchment 13B. This catchment will require minor shaping and if revisions to the existing shape of S5 are deemed necessary these works will be carried out such that the new pond will be relatively shallow to promote evaporation. Catchment 11A lies along the western boundary of catchment 11B (Figure 2). The existing storage of S11A will retain runoff from catchment 11A and discharge overflow through an existing spillway and drainage channel to S12. Catchment 11B lies along the northern boundary of the Kintore Pit (Figure 2). Existing storage S11B will retain runoff in this catchment. This storage is close to Kintore Pit, and we will therefore maintain the integrity and stability of any bunding along the edge of Kintore Pit and reinforce bunding if required to limit potential stability issues and limit the risk of release of water into the Kintore Pit. Overflows from S11B for storm events greater than the 100 year ARI will discharge into the existing drainage channel and into storage pond S12. Runoff from catchment 12 is contained within the existing storage pond S12 (Figure 2). The storage volume of this pond will be checked against the 100 year ARI rainfall event from the catchment (Table 5) and storage de-silted if necessary. Overflows from S12 report to an existing drain located in catchment 13A and to storage pond S14. Runoff from catchment 13A will enter into a new storage pond S13A. This pond will have capacity to retain the 100 year ARI storm event, with overflows from S13A discharging to the existing drain located in catchment 13, which reports to storage area S14. Reshaping of the ground levels adjacent to the existing drainage channel will be carried out to allow overflows from catchment 2 and S13A to discharge into the existing drainage channel. A proposed storage pond in catchment 13B captures runoff for the 100 year ARI storm event (Figure 5). Overflows from S13B report to the existing drain located in catchment 14 and to storage pond S14. Catchment 13B generally slopes towards the proposed S13B and as such minimal shaping will be required for the catchment. BHOP will carry out the following works: Reshape storage S2 away from the slope edge and install a new spillway and overflow channel from S2 to the drainage channel in catchment 13A. Construct a spillway at S5 and an overflow channel between S5 and catchment 13B to the existing drainage channel. Construct a new storage area in catchment 13A (S13A) to retain the 100 year ARI storm event. Carry out re-grading works to existing berm located in catchment 13A to allow for overflows from S2 and 13A to discharge to the existing drainage channel. Provide a storage pond in catchment 13B to cater for the 100 year ARI storm event and construct a spillway and overflow channel from S13B to the drainage channel in catchment 14. Report No R-Rev11 28

34 Catchment 7, 10 and 14 Direct runoff from catchments 7 and 10 are diverted to an existing drain that discharges to catchment 14 and to water storage S14 (Figure 5). Storage pond S14 will discharge runoff for events greater than the 100 year ARI event to the interconnected ponds located in catchment 17. Overflows for storm events greater than the 100 year ARI from storage areas S2, S5, S11A, S11B, S12, S13A and S13B and direct runoff from catchments 7, 10 and 14, will report to S14, and interlinked with catchment 17 storages. BHOP will carry out the following works: Install a new pipe under the access road in catchment 10. Construct pond S14 with the capacity to store the runoff resulting from the 100 year ARI storm event and provide an overflow from S14 to S17-1. If required by topographic constraints, some of the required storage for this catchment may be developed with the storages S17-1, 17-2 and 17-3 proposed in the adjacent catchment. Install culvert across the service road in catchment Catchment 15, 16, 17, 18 (partial), 20B and 20C Catchments 15, 16, 17, part of catchment 18 and 20B contribute runoff into storages in catchment 17, S17-1, S17-2 and S17-3 (Figure 5 and 6). These storage ponds are located either side of the existing Silver Tank and the electrical installation area. In order to maintain the integrity of the existing Silver Tank, S17-2 and S17-3 have been located a distance back from the tank and are bunded. The overflow from S17-1 will report to S17-2 through a proposed pipe and S17-2 will be connected to S17-3 via channel spillway. A water indicator will be installed in S17-3, which will mark the maximum water level required to ensure the storage area for the 1 in 100 year ARI rainfall event is available. Once the water level reaches the indicated level, the storage capacity of this catchment will be re-established by extracting the water from the storage by pumping to either the toe drain along the east side of Mt Hebbard or be pumped into Storage S22. Overflows from S17-3 will flow into the toe drain adjacent to Horwood Dam access track. Recent survey data levels, dated 22 February 2012, indicate the toe drain gradient is relatively flat adjacent to S17-3 prior to grading towards Horwood Dam. This flat bench area will effectively act as a spillway for overflows from S17-3 into Horwood Dam during extreme rainfall event. This overflow is expected to occur without overtopping the existing bunding to the east of the S17 storage area and the along the bench area. An assessment will be carried out to understand the risk of impacts on the Silver Tank and other infrastructure should the capacity of S17-1, S17-2, S17-3 and S14 be exceeded resulting from rainfall events in excess of a 1 in 100 year event. Catchment 20C diverts direct runoff from the area of the embankment slope of TSF 1 adjacent to the existing access track to Horwood Dam. The channel conveying runoff from catchment 20C will be located parallel to the access track. Flow pumped to the east side of Mt Hebbard will flow in a proposed channel (catchment 20C) along the base of Mt Hebbard and toe of the old Tailings Dam to Horwood Dam. The ground elevations at the location of the proposed channel are such that pumping of stormwater from S17-3 to the higher elevation in the drainage channel or over the ridge into S22 will be necessary. However once stormwater has been pumped the channel in catchment 20C it will have sufficient gradient to allow stormwater to gravity flow to Horwood Dam. Runoff in the southern section of catchment 18 will report to storage S18. Overflow from S18 will be directed to catchment 17 via a pipe. Runoff in the northern section of catchment 18 will be captured by a proposed drainage channel, which flows directly into S22. BHOP will carry out the following works: Install a culvert in catchment 16 to direct runoff to S17. Report No R-Rev11 29

35 Assess capacity of S17-1, S17-2 and S17-3 to meet water storage requirements as listed in Table 5 and maintain the integrity of the tank located within the catchment area. Assess buoyancy capacity of Silver Tank to assess maximum flooding level before pumps have to activate. Investigate the risk of flood impacts on the electrical installation between S17-1 and S17-2. Depending on buoyancy assessment outcome, if required install pumping system in S17-3 to remove water in wet periods. Shape drainage channel in catchments 20B and 20C to grade to the south and north, to suit existing ground shape Catchment 37 (Partial), 38, 38A, 40, 41 and 45 Runoff from half of catchment 37, 38, 38A and 39 for the 100 year ARI storm event will be captured in a proposed drainage channel, which drains into storage pond S41 (Figure 3 and 4). This channel will run alongside the proposed bunding and road located west of the Processing Plant. Runoff from catchments 40 and 41 will also discharge into S41. Runoff from catchment 41 will be directed down the road into the pond. BHOP will assess if some regrading works are required in catchment 40 to direct most stormwater within the catchment to S41. Overflows from S41 will flow via a pipe into storage S42A and eventually discharge to Horwood Dam. Catchment 45 has a pond (S45) that stores water before discharging to S41 via a proposed drainage channel (Figure 4). The shape of S45 will be assessed in conjunction with the pond S41 to provide the required storage for these catchments. BHOP will carry out the following works: Install a new drainage channel extending through catchment 37, 38, 39, 40 and 41 with the capacity to cater for the 100 year ARI storm event. Regrading works may be required at catchment 40. Design and construct pond S41, with overflow pipe to storage area S42A. Assess capacity of S45 to cater for design runoff volumes as outlined in Table 4. Excavate and bund to create additional storage if necessary to contain the 100 year ARI storm event. Construct a new spillway and overflow channel from S45 to storage area S Catchment 39, 39A, 42A, 42B and Horwood Dam A mine water storage pond (Plant Water Pond) is located within catchment 42B (Figure 4). The Processing Plant, located in catchments 39 and 39A, is bunded and all internal drainage networks will report to the Plant Water Pond. Water in this pond will be reused in the plant and can be augmented by water from the lined mine water ponds at S22. Overflow from the Plant Water Pond will be directed via a pipe to the Plant Event Pond, located at the toe of the embankment in catchment 42B. Overflow from this pond is directed to Horwood Dam. Surface water runoff from catchment 42B will be diverted around this pond and flow to Horwood Dam via a drain along the east edge of the catchment. Catchment 42A has a series of small sediment ponds located on and at the base of the embankment. These ponds receive runoff from within the catchment with overflows discharging to an existing drainage channel and into Horwood Dam. Horwood Dam provides storage for catchments 20C and 42B for the 100 year ARI storm event and overflow storage from upstream storage ponds S14, S17-1, S17-2, S17-3, S41, S42A and S45, as outlined in this Plan s figures (Figure 4 and 6). The estimated storage capacity of Horwood Dam is provided in Table 6 and Figure 7. Report No R-Rev11 30

36 Table 6: Horwood Dam Estimated Storage Capacity Max. Water Level Approx. Area (m²) Max. Depth (m) Approximate Volume (m³) , , , ,336 Table 6 indicates that Horwood Dam has the capacity to store more than four times the estimated 1 in 100 year ARI rainfall runoff volume (approximates to more than the 1 in 1000 year event) from the associated catchments. This provides a robust facility with a low risk of discharge even during rainfall events more severe than the 1 in 100 year ARI event. BHOP will carry out the following works: Shape the existing ground profile to accommodate for a storage pond in catchment 42 with the capacity to retain the 100 year ARI storm event. Construct Plant Water Pond and Plant Event Pond to contain the 100 year runoff from the Processing Plant area Catchment 18 (partial), 19, 20A, 21A, 21B, 22, 26 and TSF 1 Partial flows from catchment 18 and runoff from catchments 19, 20A, 21A, 21B, 22, 26 and TSF 1 will contribute runoff to S22 located in catchment 22 (Figure 3 and 6). At the north west portion of catchment 18 we are proposing to construct a drainage channel along the toe of the embankment in catchment 18 to divert water directly to S22 (Mt Hebbard Gully). The remainder of runoff from catchment 18 will be directed to storage area S18, which will overflow to S17-3. Catchment 19 is located at the top of Mt Hebbard. It is proposed to remove storage from Mt Hebbard by constructing a small drainage channel to the Mt Hebbard catchment and down the access ramp, which will drain the existing depression at the top and divert runoff to S22. By removing storage from Mt Hebbard this should reduce the risk of seepage occurring outside the boundary of CML7 at this location. Runoff from catchment 21A will be diverted to a proposed drainage channel located at the downstream boundary of the catchment. This drainage channel will extend into catchment 21B and flow to storage area S22 (Mt Hebbard Gully). Direct runoff from catchment 21B will report to a drain on the western side of the haul road and then via a pipe culvert to S22. Catchment 26 will have a proposed pond and spillway will direct water into the proposed drainage channel located in catchment 21A away from the explosives store. This area currently provides storage. The storage volume of the existing storage area will be checked and de-silted if necessary to meet the retention requirement for the 100 year ARI storm event. Runoff from catchment 20A reports to TSF 1. BHOP will investigate if reshaping of the surface of catchment 20A is required to drain the existing minor depression. The surface of TSF 1 comprises of a depression near the centre of the storage facility. The depression will be drained via a modification to the existing spillway in the south west side of TSF 1. The modification to the spillway will discharge runoff from TSF 1 and runoff from catchment 20A into S22. BHOP will carry out the following works: Construct drainage channel in catchment 18. Report No R-Rev11 31

37 Construct a drainage channel on Mt Hebbard to remove any storage capacity and allow direct runoff the S22. Construct new drains / pipes along catchment 21A and catchment 21B to direct water into S22. Reshaping of surface in catchment 21A. Check the storage volume of the existing pond located in catchment 21A against the storage requirements as outlined in Table 5. Spillway modification of TSF 1. Construction of separate storage pond compartments within S22 to cater for the mine water. Three mine water ponds are required for the mine water balance on site Catchment 23, 24, 25A, 25B and Kintore Pit Catchment 23 is a small catchment along the western edge of the mine site, west of Kintore Pit (Figure 2). Runoff within this catchment will discharge into the existing drain located in the rehabilitated zone. Catchment 24, located adjacent to Kintore Pit, currently discharges into Kintore Pit (Figure 2). It is proposed that this area be backfilled to shape the surface area to drain away from the Pit towards catchment 25B. Runoff into the pit will be limited as this is where the decline to the underground workings daylights. The reshaping can be accomplished by lowering the ridge between catchment 24 and 25B through excavation and using the spoil and additional fill the shape the area in catchment 24. The runoff from catchment 25A and 25B will report to storage S25A and S25B, respectively (Figure 3). As S25A is located in close proximity to a proposed vent shaft, BHOP will install an overflow from storage area S25A to S25B. Overflows from S25B will spread over the floor of catchment 25B. The existing catchment 25B will be slightly increased by proposed earthworks to create a platform for the construction of a vent shaft for the mine. The platform is to be formed by excavation into the side slope of the catchment 25A surface. BHOP will carry out the following works: Fill and regrade catchment 24 to direct runoff to catchment 25B. Construct two storage facilities in catchment 25A and 25B Catchment 27, 28, 29 and 34 Catchment 29 drains to the west along the approach road to the car parking area (Figure 3). The existing topography of catchment 29 allows water to pond at a low point in the catchment. It is proposed that this low storage point be retained and overflows from catchment 29 be allowed to overtop the existing road and into the storage area in catchment 28. The proposed storage pond in catchment 28 (S28) is to be located beside an existing sub-station and will capture runoff for the 100 year ARI storm event (Figure 3). In order to maintain the integrity of the existing substation, S28 will be located a distance back from the substation. Runoff from catchment 29, catchment 27 and part of catchment 34 will report to S28. Overflows from S28 will overflow to the existing access road and be directed off-site. Bunding should be constructed around the substation to protect it from overflow inundation. BHOP will carry out the following works: Construct storage facilities in catchment 28 Regrading of catchment 29. Construct bunding around substation and form storage in catchment in 28. Reshape drainage along access road to Memorial to direct part of runoff from catchments 34 into S28. Report No R-Rev11 32

38 Catchment 32, 34, 36, 37 (Partial) and BHP Pit The parking area for the Broken Earth Café and Miners Memorial is located in catchment 32 (Figure 3). This catchment is approximately 30% impervious and under existing conditions discharges into catchment 34 via a pipe culvert. Catchment 34 consists of a relativity low gradient surface and runoff from this catchment is diverted through a proposed spillway to BHP Pit. The existing culvert is expected to have a discharge capacity significantly lower than a 100 year rainfall event, and a portion of the runoff will flow down the access road and into catchment 28, once the proposed works are implemented. The discharge capacity of the pipe culvert between catchment 32 and 34 could be increased with additional pipes, if a higher portion of runoff from catchment 32 is to be directed into BHP pit. A small area of BHP Pit is currently used for explosive storage. The Pit provides ample capacity for discharge of surface runoff from the surrounding catchments. S37 collects part of the catchment runoff for catchment 37 and overflows from S37 for events greater than the 100 year ARI rainfall event will discharge into BHP Pit. Direct runoff from catchment 36 also reports to BHP Pit. The discharge into BHP Pit will require reinforcement using riprap protection at the edge of the Pit. BHOP will carry out the following works: Construct a proposed spillway from catchment 34 to BHP Pit. Install a new drainage outlet channel from S37 extending through catchment 36 with the capacity to cater for the 100 year ARI storm event. Install riprap protection at the discharge point of the proposed drainage channel and BHP Pit. Construct a new storage facility in catchment 37 to contain the 100 year ARI runoff from the contributing area within the catchment. Install a spillway to allow overflows to discharge to the drainage channel Catchment 30, 31, 46 and 47 Catchment 30 consists of the slope area to the west of the Broken Earth Café and Miners Memorial (Figure 3). An existing collection drainage channel attenuates runoff from catchment 30 with overbank flows reporting to catchment 31. Catchment 46 and 47 will be connected to catchment 31 via an east-west drain along toe of the slope (Figure 4). Existing low points located in catchment 31 (S31-1 and S31-2) will be used to store the 100 year storm event runoff from catchments 30, 31, 46 and 47. The proposed pond/storage will require de-silting to obtain the volume required to store the 100 year event. BHOP will carry out the following works: Maintain existing drain in catchment 30, 31, 46 and 47. Assess the existing capacity of S31-1 and S31-2 to cater for the 100 year ARI rainfall event and reshape if required to increase capacity Catchment 33, 35, 43 and Blackwood Pit Catchment 33 currently discharges into catchment 35 via two pipe culverts (Figure 3). BHOP will assess the discharge capacity of these pipes to carry a 100 year event and if necessary install additional pipes. Catchment 35 will be re-graded to create a pond (S35) to contain the 100 year storm event from both catchments. The overflow from S35 during extreme rainfall events will discharge to Blackwood Pit. Blackwood Pit has a current storage capacity of more than 2,000,000 m³. This available storage volume will reduce as tailing s deposition occurs in the Pit, however the volume of stormwater runoff discharging to Blackwood Pit is minor compared to the storage available. It is anticipated that at the final stages of tailings deposition there will be adequate capacity in Blackwood Pit to cater for tailings and stormwater runoff from the 1 in 100 year rainfall event. A pumping system will be installed in Blackwood Pit to remove supernatant water from the tailings and stormwater runoff into the Plant Water Pond located in catchment 42B, for use in mining operations. Report No R-Rev11 33

39 Catchment 43 lies to the east of Blackwood Pit and is relatively flat but contains a small low lying area S43 (Figure 4). The overflow from S43 will report to Blackwood Pit. BHOP proposes the following works: Assess current discharge capacity of existing pipes from catchments 33 to 35; install additional pipe work or spillway, if required. Regrade to create pond storage S35, install a spillway from this pond to Blackwood Pit Catchment 44A, 44B and Rail Siding Facility Rail operations are proposed along the catchment north boundary of catchments 44A and 44B (Figure 4). A sediment pond is proposed as part of rail siding to collect runoff from the load-out area. This pond will retain water separate to the rest of site runoff, as this area is considered part of the active area of the mine operation. A stormwater runoff pond is to be constructed (S44) at the topographic low spot north of catchment 44B. S44 will collect runoff from catchments 44A, 44B and some contribution from the land to the west of the mine area. S44 will discharge into a new culvert that will be constructed under the new rail siding formation to accommodate the flow from S44 and the catchment to the south of the new rail siding, into the existing stormwater pond to the north of the railway line. A minor amount of runoff will flow down the existing rock slopes on the north east corner of the site, on the outside boundary of catchments 42A and 44A. It is proposed to construct small sediment ponds at these locations to intercept the runoff from the slopes. These ponds should be included in the alignment of reconstructed fence in this area once the rail siding has been completed. Required works include: Construct drain along the haul road in catchment 44B. Construct a drain in catchment 44A on the south side of the rail load-out area. Construct a culvert under the new rail siding. Construct a sediment pond near the low point adjacent the hardstand area of the proposed rail sliding facility. Construction a runoff water pond S44 to capture runoff from the catchments 44A and 44B Catchment 48 and 49 Catchment 48 and 49 are located in an area known as Block 10 Lookout, at the western boundary of the Rasp Mine site. This area is classified as a rehabilitated zone and is not directly disturbed by current or proposed mining activity. Rainfall runoff in catchment 48 flows in an easterly direction into a drain that discharges under the public road (Gaffney Street) to the Olive Grove. The integrity of the existing drainage channels located within catchment 48 will be assessed to cater for the 1 in 100 year ARI event. The proposed drainage channels will convey flows into Olive Grove for storm events up to and larger than the 1 in 100 year ARI while also providing attenuation capacity. Three small stormwater storage basins (collectively labelled as S49) are located in catchment 49 and currently collect runoff from the catchment. Overflow from S49 discharge through an existing spillway and into the street stormwater drainage system. The runoff volume in catchment 49 is to be limited by the construction of a bund to direct runoff from the upper part of the natural catchment and divert flow into the existing gully in catchment 48. This will limit the storage capacity required in S49. Report No R-Rev11 34

40 Following recent rainfall events in March 2012, seepage occurred through the existing S49 bund and into street drainage. In response a small trench was installed to prevent further seepage and arrangements made for on-going water removal from the trench. An investigation is current for more permanent works to prevent seepage flows from S49. BHOP will carry out the following actions: Verify if current storage ponds in catchment 49 are adequate to cater for 100 year ARI and construct overflow structure. Construct the diversion bund along the boundary of catchment 48 and 49. Check the capacity of the drain along the boundary of catchment 48 against the estimated 100 year ARI runoff from the catchment. Check the capacity of the existing pipe culverts to cater for the design 100 year ARI rainfall event from catchment Peak Flow Estimation The Rational Method was applied in estimating the peak flow rates from selected catchment areas that outfall through proposed hydraulic structures, such as culverts and pipes, or into proposed drainage channels. The estimated peak flow may be applied in the preliminarily sizing of culverts or in selecting geometric dimensions for drainage channels. The peak flow provided in Table 7 accounts for flow from basins overflowing into other basins up to a 1 in 100 year rainfall event.. The construction and shaping of the drainage channels and culverts will include a freeboard of 300mm above the estimated water level for the 100 year ARI event. The Rational Method formula applied in the estimation of peak flow is: Qy = 0.278CIA (The Institution of Engineers Australia, 1998) Where Qy I A C Peak flow rate (m³/s) Average rainfall intensity (mm/hr) Area of the catchment (km²) Runoff Coefficient The average rainfall intensity for a time of concentration (tc) and a 100 year ARI was estimated based on BoM Design Rainfall Intensity Chart for the Rasp Mine area and the Bransby Williams formula for time of concentration. The peak flow rates entering proposed drainage channels and hydraulic structures were estimated as followed: Report No R-Rev11 35

41 Table 7: Peak Flow Estimation applying the Rational Method and Bransby Williams Formula Catchment Number Hydraulic Structure or Drainage Channel Location Return Peak Flow 100 year (m³/s) 1, 3, 4 Culvert Crossing 7, 10, 14 Drainage Channel Under existing road linking catchment 1 to S1A Drainage channel to S14, receiving runoff from catchments 7, 10 and m³/s m³/s 42B Drainage Channel Drainage Channel receives overflows from S42 and direct runoff from 42B, m³/s 24 Culvert Crossing Under ridge linking catchment 24 to S25B m³/s 32 Culvert Crossing 36 Drainage Channel Links catchment 32 to catchment 34 Capturing flow from catchment 36 and overflows from S37 to BHP Pit m³/s m³/s 46, 47 Drainage Channel Capturing flow from catchment 46 and m³/s 48 Culvert Crossing Under existing road linking catchment 48 to Olive Grove m³/s Report No R-Rev11 36

42 11.0 GROUNDWATER MONITORING PROGRAM 11.1 Introduction Schedule 3 Condition 23(d), of the Project Approval, details the requirements for the groundwater monitoring program as: Provide a program to monitor seepage movement within and adjacent to the tailings storage facility; Include details of parameters and pollutants to be monitored for: Water from mine dewatering; Groundwater locations to the east of TSF 1; Surface water represented by Horwood Dam; Water captured by the toe drains of the tailings storage facility; Water seepage from the tailings storage facility; and The background local groundwater system. Outline performance parameters against monitoring data will be compared to assess whether seepage is occurring, and whether an unacceptable impact on local groundwater may be occurring; Include details of contingency This section outlines the groundwater monitoring program for the Rasp Mine. The regional groundwater near the site is depressed due to long term pumping from the underground mines in the area, resulting in the depressed groundwater level below the site being more than 100 m below the surface level, with a hydraulic gradient into the site at depth. The groundwater monitoring program will be undertaken with the purpose of recording perched groundwater movement. Perched groundwater refers to surface water that has infiltrated into near surface moderate to high permeability material generally comprising of granular soils and rock fill. The perched groundwater exists for short periods of time after rainfall events and generally seeps laterally over the low permeability bedrock surface below the near surface permeable material. The recent rainfall events at Rasp Mine site indicate that the perched groundwater has potential to surface seep rather than seep into the regional groundwater. Considering the depth of the regional groundwater it is concluded that there is little interaction between the shallow perched groundwater and the regional groundwater. The objectives of the groundwater monitoring program are to: Provide a program to monitor seepage movement within and adjacent to the tailings storage facility Provide details of parameters and pollutants to be monitored and background local perched groundwater parameters Establish a contingency measure in the event that an unacceptable impact is identified Program to Monitor Seepage Movement Some short term perched seepage may occur from surface water infiltration into the permeable rock mounds on the site. When the volume of infiltrated water is high, resulting from significant rainfall volume at the site, the rock mounds may reach field capacity and result in seepage through the rock mounds. The seepage may exit laterally from the rock mounds, when the seepage front reaches the high strength low permeability rock formation generally below the site. Such short term seepage may present itself as near surface seepage zones as those that occurred in 2011, following heavy rain in Broken Hill. Stormwater management Report No R-Rev11 37

43 for areas where seepage was noted in 2011 has been revised to reduce or eliminate the extent of surface ponding near these areas to limit the volume of water infiltration into the rock fill mounds. The perched groundwater monitoring bores will record the depth at which seepage may occur. The monitoring bore depths will not extend to the drawn down regional groundwater level resulting from long term mining activity in the area. The seepage noted on site after the 2011 rainfall events and the subsequent investigations informed the basis to develop the proposed groundwater monitoring program. The existing and proposed monitoring boreholes will provide an early warning sign if seepage is occurring near the CML7 lease boundary. Water from mine dewatering at Shaft 7 and from the mine decline will form part of the groundwater monitoring program. Samples of groundwater will be collected every three months, water permitting. The location and function of each borehole is listed in Table 8. Table 8: Location and Function of Mine Dewatering Samples and Groundwater Monitoring Boreholes Groundwater Borehole ID/ Mine Dewatering Location Function / Purpose GW01, GW02 South east of Mt Hebbard To monitor if seepage is occurring from Mt Hebbard GW03, GW05, GW07, GW09 GW10 GW11, GW12 GW13, GW15 GW16 GW04, GW06 GW08, GW14, East of TSF 1 Downstream of Horwood Dam Proposed east of Blackwood Pit Adjacent to storage areas S44, S31-1 and S31-2 To the west of storage area S49. To monitor potential seepage flows from TSF 1 towards the CML7 mine lease boundary To monitor potential seepage north of Eyre Street Dam. Proposed borehole to monitor potentially perched water as a result of potential groundwater mounding from TSF water To monitor if movement of perched groundwater is occurring from the storages. To monitor potential seepage west of S49. Shaft 7 Shaft 7 To assess groundwater quality of pumped water from Shaft 7 Mine Dewatering Decline at Kintore Pit To assess groundwater quality at decline The locations of the shallow groundwater monitoring bores are presented on Figure 8. The area located to the north and east of the Rasp Mine forms part of Perilya s mine lease. The ore body strikes from the north east of Rasp Mine to Shaft 7, where dewatering takes places. The regional groundwater draw-down cone is therefore expected to exist along this ore body alignment resulting in significant depth to regional groundwater north east and south west of the Rasp Mine lease boundary. The south-west to the north-west area of the Rasp Mine was historically extensively mined by underground workings comprising shafts, drives and stopes and as such it is not expected that groundwater will be encountered in this area due to the existence of the drained old mine working. Proposed new underground mining is also scheduled to occur under the western part of the mining lease. Hence no groundwater monitoring bores are proposed to the west of Blackwood pit GW01 and GW02 Located Downstream of Mt Hebbard An investigation was undertaken in June 2011 at Rasp Mine related to perched water beneath the surface at Rockwell Street. This investigation consisted of drilling two boreholes GW01 and GW02, located at the Report No R-Rev11 38

44 corner of Mt Hebbard and installing a standpipe piezometer into each borehole. The bores indicated 3m and 9m of fill at the two locations, overlying very high strength Gneiss. The results of this investigation focused on monitoring sub-surface water fluctuations south of Mt Hebbard, within the encountered fill and identified the sub-surface water level at approximately 5.6 m and 6.3 m below ground level at the monitoring boreholes at the time of the investigation. These boreholes will form part the groundwater monitoring program GW03, GW04, GW05, GW06 GW07, GW08 and GW09 Located Adjacent to TSF 1 Groundwater bores are located near the eastern side of TSF 1. The intent of the monitoring bores is to monitor perched seepage from the TSF 1 area and Eyre Street Dam. The monitoring is in response to surface seepage noted in the area during intense 2011 rainfall events. Improvement works are proposed in response to the seepage, and the monitoring bores form part of a monitoring program to assess the effectiveness of the proposed improvement works. TSF 1 is a decommissioned TSF and will not be recommissioned GW10 Located Downstream of Horwood Dam The monitoring bore located downstream of Horwood Dam was installed to monitor water flows in the area. The investigation of 2011 indicated that the perched seepage measured at this bore is not related to water from Horwood Dam GW11 and GW12 Located Adjacent to Blackwood Pit Blackwood Pit forms part of the mining area with underground mine working to the west, north and south of the Pit. Due to the existing workings, seepage from the Blackwood Pit will be intercepted and collected by the underground mine water management system and therefore the installation of groundwater monitoring bores at this location is of no benefit, as no watertable is expected to exist or develop within the old mine workings. The ground conditions to the south east of Blackwood Pit are relatively intact with no or limited mine workings in the area. Due to the north east and south west length of the Pit there is a possibility for the formation of a perched aquifer as a result of groundwater mounding around the south east side of pit once it receives tailings. Two monitoring bores, labelled GW11 and GW12, will be installed to the south east of the Pit as part of the groundwater monitoring program to a depth of 5 meters below the base level of Blackwood Pit. The proposed location of the bores have been selected based on the lower ground level towards the south east of the Pit, and to be outside the influence of the isolated mine drives on the south-east side of the Pit. If a perched water table is measured in the two bores consideration will be given to the installation of additional bores to assess the local hydrogeological conditions and risk of migration of seepage. The groundwater monitoring program will be focused at the Blackwood Pit where a medium term source of water will be developed as a result of tailing deposition GW13, GW14 and GW15 Located Adjacent to S44, S31-1 and S31-2 Perched seepage may occur from ponds located near the CML7 boundary, when these ponds store water. During construction of these ponds the permeability of the basin materials will be assessed to decide if a liner is required to form a low permeability basin in the pond and reduce the risk of perched seepage from the pond into the near surface soils. Three ponds are located next to the CML7 boundary along the west side of the site. In response to EPA s specific request, a shallow perched groundwater seepage detection and monitoring bore will be located to the west of each of these ponds. GW13 and GW14 monitoring bores are located adjacent to the proposed stormwater retention ponds S31-1 and S31-2. Water quality in the monitoring bores will be compared to water quality in the ponds. The nominal depth of these bores will be 4 m or at least 1 m into the expected underlying bedrock near the ponds. Report No R-Rev11 39

45 GW15 monitoring bore is located to the west of stormwater retention pond S44. The monitoring bore will be located to the west of S44 to monitor potential seepage from the pond. The depth of the bore will be relatively shallow to ensure potential seepage is not being monitored from the existing pit pond to the west next to the railway line. It is expected the monitoring bore will be approximately 4 m deep GW16 Located Adjacent to S49 A monitoring bore located west of S49 will be installed to monitor potential perched seepage from this storage. The water quality in the bore (if any exists) will be compared to the water quality of the storage water to decide if any further works are required at this storage Water from Mine Dewatering Sampling of mine dewatering from Shaft 7 and the mine decline will form part of the groundwater monitoring program. Sampling will be carried out at the mine water ponds in S 22, where water from underground will be discharged into individual storage pond compartments. The central three compartments in S 22 are to be lined for the storage of underground water. The compartments will be lined to limit the risk of possible mixing of underground water with surface water runoff also being stored in S 22. Therefore the samples to be taken at the central compartments in S 22 are representative of the decline and Shaft 7 samples. Sampling from mine dewatering will be carried out every three months Eyre Street Dam Seepage In 2011 seepage occurred at the toe of the Eyre Street Dam. An investigation of the source of seepage resulted in recommendations for improvements in this area. These improvements will be implemented on site and the improvements are documented and monitored via a pollution reduction program administered under the sites Environment Protection Licence. According to historical documents Eyre Street Dam situated adjacent to TSF 1 formed part of the mine s water management system. An open cut trench running along the toe of the TSF 1 formerly directed water to the Eyre Street Dam. Water was then pumped from the Eyre Street Dam to the adjacent Horwood Dam, which in turn was pumped to the Olive Grove Pond. Seepage will be monitored by the existing bores described in Section and Section Groundwater Quality Parameters Baseline Chemical Properties of Groundwater Groundwater quality monitoring was undertaken in May 2007 and August 2011 at Shaft 7. Although seasonal or other non-mining influences have not been characterised at the Rasp Mine, these water quality monitoring results will act to establish initial baseline parameters and trigger levels for the monitoring program. In the interim and until trends in chemical parameters have been established, groundwater quality results for August 2011, will be used as baseline data for assessing changes in groundwater and perched groundwater quality results. Groundwater quality results for May 2007 and August 2011 are contained in Appendix A Selected Groundwater Quality Monitoring Parameters Groundwater quality monitoring at the proposed groundwater monitoring bores will be undertaken. Table 9 indicates the groundwater analytical suite which will be monitored. Report No R-Rev11 40

46 Table 9: Groundwater Analytical Suite Parameter Unit Recommended Analytical Method General Water Quality Parameters (field) ph ph Unit Field Meter General Water Quality Parameters (laboratory) Electrical Conductivity µs/cm APHA Method 2510 B Total Dissolved Solids (TDS) mg/l APHA Method 2540 C Major Ions Total Alkalinity mg/l as CaCO 3 APHA 2320 B Sulphate (SO 4 ) mg/l APHA 4110 Chloride (Cl) mg/l APHA 4110 Calcium (Ca) mg/l USEPA 3015A Magnesium (Mg) mg/l USEPA 3015A Sodium (Na) mg/l USEPA 3015A Metals (Dissolved) Iron (Fe) mg/l USEPA 3015A Cadmium (Cd) mg/l USEPA 3015A Lead (Pb) mg/l USEPA 3015A Manganese (Mn) mg/l USEPA 3015A Zinc (Zn) mg/l USEPA 3015A Notes: mg/l - milligrams per litre µs/cm - microsiemens per centimetre Contingency Measure in the Event of an Identified Unacceptable Impact It is necessary to establish the quality of surface water collected from waterbodies within the mine lease such as Horwood Dam to compare the results to the measured groundwater quality. An assessment can then be made as to whether a change in groundwater and surface water conditions on site is occurring. Any changes will be assessed based on trend changes relative to the baseline chemical properties of Groundwater The site groundwater is deep and is related to mining activities. The water is extracted as part of mining. The underground extraction system results in inward flow of the groundwater into the mine. Hence groundwater at the mine is likely to be impacted by off-site sources due to the inward hydraulic gradient into the mine. If contaminates are detected greater than 30% above the baseline 2011 groundwater quality values, measured at Shaft 7, of collected water in the S22 mine water compartments, will be investigated Perched Groundwater Perched groundwater quality is expected to contain significant concentration of lead, manganese and zinc, due to the seepage contact with the near surface materials on site and the surrounding areas. Perched groundwater occurs periodically after significant rainfall, so monitoring ability will be sporadic. Where frequent groundwater seepage is identified BHOP will investigate the option to intercept the seepage and direct the seepage into site water ponds for management as part of the site water management system. These measures may include seepage collection drains with a sump, lining of the area related to the source of the seepage or construction of additional surface water management structures to direct flow or storage away from the perched groundwater affected area. Report No R-Rev11 41

47 Contingency measures to address groundwater impact may also include the investigation of groundwater extraction at the area of concern. The extent and degree of the contingency measures will be assessed once groundwater quality trends are confirmed. Potential seepage from the Blackwood Pit related to the tailings may occur. Most of this seepage is expected to occur into the underground workings, and will be extracted and managed as part of the underground mine water management. If seepage occurs towards the east of the site it is expected to be measured in the monitoring bores GW11 and GW12 to the east of the Pit. Once a trend is suspected, or if most contaminates are detected greater than 30% above the 2011 baseline values, an investigation will be undertaken to determine the source of contamination, the level of environmental risk and the remedial action required. Options for remedial actions include the following: Changes to the tailings deposition method and strategy to limit water storage on the tailings surface. Changes to the tailings deposition water content to reduce the amount of water in the tailings storage facility. Installation of perched groundwater extraction system through a series of bores or cut-off trench adjacent to the site boundary. Report No R-Rev11 42

48 12.0 SURFACE WATER MONITORING 12.1 Monitoring Program for Creeks and Other Waterbodies There are no natural watercourses or creeks flowing through the site. The proposed drainage network layout restricts runoff leaving the active area of the site up to the 1 in 100 year event. Horwood Dam has a large additional storage capacity in excess of the 100 year runoff volume that is directed towards the Dam. Hence discharge from Horwood Dam may occur in events significantly rarer than the 100 year event, up to 1 in 1,000 year event. Consequently any discharge from Horwood Dam in a rare rainfall event will be of very low concentration due to the large volume of water required to bring the dam to a discharge event. The following storages are located where a discharge from the storage related to rain events with an annual exceedance probability of 1 in 100 years or greater volume of water may extend outside the CML7 boundary. These storages are: S1A is a large storage and is likely to discharge in very rare events. Discharge is in a southerly direction. S31-1 and S31-2 located between the railway line and waste rock slopes. A discharge from these ponds is likely to flow into the railway property (as per design by John Miedecke and Partners Pty Ltd, CML7 Broken Hill Stormwater Management Plan, dated 23/10/2000) S44, which would discharge into the existing large surface water pit adjacent to the railway line. The large surface water pit has large storage capacity and is unlikely to discharge due to its depth. S49 located in the area known as Block 10 Lookout. As part of detailed design the option to discharge excess runoff (in excess of 1 in 100 year event) to a local depression immediately to the north west of the storage would be investigated to limit the likelihood of excess flow down Adelaide Street. S9B-1, S9B-2 located at the south east corner of the site may discharge off site during events rarer than the 100 year rainfall event. The contributing catchments to these ponds are quite small and it is anticipated that discharge will enter into the town s stormwater system. None of these storages discharge directly into any creeks or natural waterbodies. For rare storm events, any discharge to the surrounding environment is likely to be diluted from large volumes of surface water outside of the mine lease area. Based on the above, surface water monitoring, as outlined in Project Approval (reference 07_0018) Section 3 Condition 23(c), is considered appropriate for Horwood Dam, being the only storage that may potentially discharge to an off-site tributary approximately 18 km upstream from the confluence with Stephen s Creek, at the east of the site. Aerial photographs indicate that there are no other natural watercourses adjacent to the rest of the Rasp Mine. It is predicted that overflows during extreme rainfall events greater than the 1 in 100 year storm event, will not directly affect the hydrology of the local catchment. BHOP will continue to review offsite discharge, which may occur or is reported to occur by local residence, and will establish an offsite monitoring program at locations where discharge incidences are reported Monitoring Program for Stormwater Ponds Monitoring of water quality of the following stormwater ponds will be carried out if the ponds contain water. The water quality results will be also used to compare to groundwater quality to be measured in groundwater monitoring bores near four of these ponds: S1-A Report No R-Rev11 43

49 S31-1 and S31-2 S44 S49 S9B-1, S9B-2 The pond water quality of S1A, S31-1, S31-2, S44, S49, S9B-1 and S9B-2 will be measured at least twice a year when the pond has contained water for at least one week and the volume of stored water is at least 20% of the pond capacity. Runoff into ponds S31-1 and S31-2 is not related to active mining operations but to runoff from areas historically related to mining classified as heritage listed slag heaps. The proposed groundwater monitoring bore to be installed north west of S31-1 and S31-2 will identify if seepage is occurring from these ponds. A review of the seepage monitoring results will form the basis of an outcome design to manage the risk. The integrity of engineering bunds at storage areas S49, S9B-1 and S9B-2 will be assessed and if required additional engineering measures will be carried out to the bunds to limit the potential risk of surface seepage occurring. It is expected the ponds listed above will be dry for most of the time so the subgrade around the pond will be partially saturated, resulting in very low permeability conditions. Hence short term storage of water is expected to result in limited moisture migration into the subgrade which will be extracted by evaporation once the pond is empty again Monitoring Program for Horwood Dam Monitoring of surface water in Horwood Dam will be carried out at least once a year after, storm events and when the level of water within Horwood Dam is within 300 mm (± 20 mm) from discharge occurring from the Dam. BHOP will install a level gauge in Horwood Dam, which will indicate when water levels are close to the 300 mm level. Samples of surface water together with the water depth will be analysed and recorded at times when the gauge level indicates water levels are close to discharge from the dam. Water quality sampling will occur at the location of the level gauge. Volume estimates of Horwood Dam indicated the 100 year ARI storm event with an estimated runoff volume of 7,663 m³ has a corresponding water level of approximately RL m. At an elevation of m (300 mm below the discharge elevation of RL m) the volume of storage is approximately 24,729 m³, which is 17,066 m³ greater than the 100 year ARI required storage volume. This is more than three times the 100 year ARI runoff volume form the dam s catchment. The volume of storage at RL is approximately 30,336 m³ (22,673 m³ greater than the 100 year ARI required storage volume), which is equivalent to approximately the runoff from a 1 in 1,000 year rainstorm event at this site if the Dam is near empty at the time of the storm Selected Surface Water Quality Monitoring Parameters No background water quality values have been set for surface water and a monitoring program will establish trends in water quality after significant rainfall events. Results from hydrochemical analysis conducted on the perched water and surface water during the Eyre Street Dam investigation during 2011 concluded results that there was no clear distinction between perched water from different areas. Surface water quality parameters will be measured when water is available. Table 10 indicates the surface water analytical suite which will be measured. Report No R-Rev11 44

50 Table 10: Surface Water Quality Analytical Suite Parameter Unit Recommended Analytical Method General Water Quality Parameters (field) ph ph Unit Field Meter General Water Quality Parameters (laboratory) Electrical Conductivity µs/cm APHA Method 2510 B Total Dissolved Solids (TDS) mg/l APHA Method 2540 C Major Ions Sulphate (SO 4 ) mg/l APHA 4110 Chloride (Cl) mg/l APHA 4110 Sodium (Na) mg/l USEPA 3015A Metals (Dissolved) Cadmium mg/l USEPA 3015A Lead (Pb) mg/l USEPA 3015A Manganese (Mn) mg/l USEPA 3015A Zinc (Zn) mg/l USEPA 3015A Notes: mg/l - milligrams per litre µs/cm - microsiemens per centimetre 12.5 Contingency Measures An extreme rainfall event approximately equivalent to the 1 in 1,000 year ARI event will need to occur before discharge from Horwood Dam is expected. Sampling of a downstream creek to the east of the site is therefore impractical and of limited benefit due to the large expected volumes of water flow in the creek during such an extreme event. Should the measured water quality in Horwood Dam be considered to present a significant risk to the water quality in the creek should Horwood Dam discharge water, then the water level in Horwood Dam would be lowered by pumping to increase its storage capacity for subsequent rainfall events. This strategy will reduce the risk of discharge from Horwood Dam during and following rainfall events, and thereby reduce the risk of discharge of affected water to the receiving water body. Water pumped from Horwood Dam could be stored either in the BHP Pit, in Blackwood Pit (TSF 2) or in S22. All of these storages have additional storage capacity compared to the estimated 100 year ARI runoff from each of the catchments. The risk to the receiving water body would be based on the background water quality in the creek and the water quality of runoff from the catchment of the creek. It should be recognised that the catchment comprises lead affected soils, so catchment water quality is expected to contain concentrations of lead and other heavy metals above the conventional water quality guideline limits in, Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000). Report No R-Rev11 45

51 13.0 WATER BALANCE 13.1 Introduction Schedule 3, Condition 23 of the Project Approval requires the preparation and implementation of a Site Water Balance. A schematic flow diagram for Year 5 mining operations was selected to reflect the water balance occurring on site. The water management strategy for the Rasp Mine is illustrated diagrammatically in Appendix B. The flow diagram identifies the sources of water supply, the use and management of water on site and quantifies the off-site transfer of water Water Sources The total water extraction for the Rasp Mine is estimated at 370 MLpa. The Rasp Mine has existing connections to both Broken Hill s potable and raw water supply networks. Broken Hill water supply comes from the Stephen s Creek Reservoir, Umberumberka Reservoir, Imperial Lake (emergency supply only) and Menindee Lakes Scheme on the Darling River. The following water supplies will be utilised over the life of the Project: 1) Potable water (4 MLpa): water from the town supply is treated at the Mica Street treatment plant and supplied to the Rasp Mine via existing connections and is used for showers, toilets and laundry (bottled water is provided for drinking). 2) Raw water (51 MLpa): water from the town supply is supplied untreated to the Rasp Mine via existing connections and is used in the Processing Plant and for dust suppression on roads and stockpiles. 3) Underground extracted and reclaimed water (309 MLpa): water reclaimed from Shaft 7 (198 MLpa) and underground mine workings (110MLpa, includes a 20% contingency for wet years), this water is treated and used in underground backfill and in the processing plant. The Rasp Mine also uses reclaimed water from various sources wherever possible for example; the decant water from TSF tailings, Horwood Dam, Plant Water Pond, and any other water storage areas that have sufficient water for pumping Water Demand and Use On-Site The primary use of water will be for the Processing Plant activity with some water losses occurring due to underground backfilling, water retained in the tailings, water in concentrate, water used for dust suppression and seepage at the TSF. The closed water circuit for the mining operations will result in complete management of process water with no off-site wastewater discharges directly from the operations other than the conventional sewage discharge. Collection ponds are proposed in the vicinity of the processing activities to capture and return potentially mineralised sediment to the processing circuit. The key aspects of the water management strategy include: The separation of raw water and potable water requirements. Raw water mining requirements includes processing, workshop, vehicle wash-bay and dust suppression, while potable water requirements includes for showers, toilets and laundry. Reclaiming of water from the tailings storage facility to the Processing Plant. Reclaiming of water for preparation and pumping of underground backfill. Monitoring and updating of the water balance will be ongoing as mining operations progress. Observations regarding the rate of water usage and the effectiveness of the water balance on site will be reviewed periodically. Report No R-Rev11 46

52 14.0 WATER QUALITY PROTECTION Above ground fuel and chemical storage facilities will be controlled and managed effectively to limit potential negative impacts on the quality of surface water or groundwater. Best management practices and compliance with the relevant regulatory requirements and provisions under the Environmental Protection Act 1986 for the installation and operation of above ground storage facilities on prescribed premises Chemical Spill Management A procedure for chemical spill management applies to all personnel and contractors whom work in areas of the mining site where chemical substances are transported, purchased, stored or handled that are potentially hazardous. Occupational Health and Safety guidelines are followed at all times on site when identifying potential chemical spills, carrying out risk assessment and risk control procedures. Personnel that use or handle chemical substances will have an understanding of the Material Safety Data Sheet including special requirements for spill control. On-site specific training for chemical spill management will be provided to personnel. Spill kits are made available at locations where a risk assessment indicates that they are required. Spill kits are clearly labelled and located in easily accessible areas for personnel to access. Personnel are trained in the appropriate use of the spill kits contents in the case of an emergency Chemical Storage Facilities A permanent refuelling location is planned adjacent to the workshop. This refuelling facility will include oils and lubricants contained in either self bunded storage containers or a bunded area capable of holding 110% of the oils and lubricants. The refuelling station will be bunded so that any spills will be contained, collected and passed through an oil / water separator. Potential spills will be contained by the bunding while the hardstand area will be graded so that chemical spills shall flow towards a sump area. Fuel and lubricants which have to be transferred to remote equipment will be transported via a purpose built fuel trailer. Hazardous substances will be stored in bunded and roofed facilities where appropriate to prevent the entry of stormwater Vehicle Washing Facilities The following describes the vehicle washing facilities that form part of the Project infrastructure. Two wash bays will be located adjacent to the mechanical workshop to enable vehicles and equipment to be clean prior to regular maintenance. An existing small wash bay will continue to be used for light vehicles. A separate dedicated wash bay will be required for larger vehicles and heavy equipment. Raw water will be used for washing in both bays. The water drains from the wash bays to an existing oil / water separator and into a series of existing settlement / evaporation dams. The settlement from the dams will be regularly collected for disposal on-site in the BHP and / or Blackwood Pits. All vehicles that have entered passed the boom gate access point will be required to be washed down prior to leaving site. This is to remove any potential lead contamination that may be on the vehicle. For this purpose a vehicle wash facility has been installed as part of the exploration decline development. It is located on the main exit road prior to the boom gate access point. The main features of this facility are: Fully automated wash system. Deluge designed to wash wheels and undercarriage of cars and trucks. Waste water treatment and recycling systems. Sediment collection and removal system. Raw water will be used for the initial system fill and top up water. All water used in the washing process (including manual vehicle washing facility and auto wash station) will be collected and recycled through a Report No R-Rev11 47

53 treatment system; including oil/water separator and sediment collector. The sediment will be collected on a regular basis for disposal in the BHP and / or Blackwood Pits. The capacity of the facility is in excess of 1000 vehicle movements per day. A small wash pad and hose is provided near this facility for manual washing of delivery vehicles that cannot pass through the vehicle wash facility. Report No R-Rev11 48

54 15.0 REPORTING AND REVIEW 15.1 Reporting Groundwater or Surface Water Incidents Internal All incidents related to ground and surface water shall be recorded and reported using the BHOP system for incident reporting and investigation. The Department Manager for the area where the incident occurred is responsible for investigating and reporting the incident. An operational incident related to ground or surface water includes: Any off site release, e.g. seepage, leakage, discharge. Any exceedences of trigger levels or trend changes to chemical parameters. In the interim and until trends in chemical parameters have been established, groundwater quality results for August 2011, contained in Appendix A, will be used as baseline data for perched groundwater and surface water trigger levels. All significant potential incidents (SPIs) are required to be reported to the Mine Manager, CBH Group Manager Safety Health Environment Community, CBH Corporate Operations Officer and CBH Managing Director External Incidents that have the potential to cause environmental harm are required to be reported to (refer Project Approval Schedule 4 Condition 5 and EP Licence): Department of Planning and Infrastructure Environment Protection Authority, and Other relevant government agencies e.g. BHCC, Health, WorkCover, Fire and Rescue. Notification shall be made immediately to each relevant authority when material harm to the environment is caused or threatened. In accordance with the Protection of the Environment Legislation Amendment Act BHOP will provide a written report, as required, within seven days of the date of the incident. The Environment Coordinator will be responsible for preparing reports to government agencies which will be signed off by the General Manager prior to submission Complaints Management Any ground or surface water related complaint will be recorded in the complaints register and investigated to identify the root causes; corrective actions will be implemented where necessary. All complaints will be documented in accordance with the Procedure - Complaints Handling. The following additional information shall also be recorded: Date. Specific Time. Prevailing Meteorology (rain, storm). Location of incident. Predicted volume. Report No R-Rev11 49

55 Duration of discharge Erosion and Sediment Transportation Reporting An Inspection Check List records the location and works carried out on the drainage system and on batters following storm events and on a quarterly basis. The Inspection Check List is used to develop improvements if areas are in frequent need of repair. The EPA will be notified of any significant changes to existing runoff and erosion control plans at the Rasp Mine as part of the Annual Environment Management Report Regular Reporting The following reports shall be prepared and submitted: Weekly Head of Departments Meeting Summary of incidents, including cause and actions taken (or to be taken) to prevent a recurrence. Summary of monitoring results Rasp Mine Website Summary of monitoring results, updated quarterly. Summary of community complaints, updated monthly. A current copy of the approved SWMP Annual Return and Annual Environment Management Report Ground and surface water monitoring results and compliance with consent and licence conditions will be reported in the Annual Return to the EPA and the Annual Environmental Management Report (AEMR). An Annual Return outlining monitoring results, non-compliances (in regards to the EP Licence 12994) and community complaints will be prepared on the appropriate form and submitted to the EPA as required each year. The Annual Environmental Management Report (AEMR) will be provided to government agencies for consultation and submitted to Division of Resources and Energy, NSW Department of Trade & Investment, Regional Infrastructure & Services (DTIRIS) each year Annual DP&I Report In accordance with Project Approval (Schedule 4 Condition 3) an environment performance review will be conducted annually and provided to the now Department of Planning and Infrastructure (DP&I). These review reports will commence at the end of June 2012 and annually thereafter. This review will: a) Include a comprehensive review of the monitoring results and complaints records of the project over the past year, which includes a comparison of these results against the: Relevant statutory requirements, limits or performance measures/criteria. Monitoring results of previous years. Relevant predictions in the documents EAR, PPR and their respective response to submissions and BHOP Statement of Commitments. b) Identify any non-compliance over the past year, and describe what actions were (or are being) taken to achieve compliance. c) Identify any trends in the monitoring data over the life of the project. Report No R-Rev11 50

56 The AEMR will be submitted to the Director General DP&I to meet this condition Auditing and Review Site Water Management Plan Review The SWMP will be reviewed, and if necessary revised, within three months of submission of: An Annual Review. An Incident Report related to ground or surface water. Any modification of the Project Approval. Modification to the EP Licence. Any review will reflect changes in environmental expectations, technology and operational procedures as well as operational experience gained as mining progresses. In addition to the above review requirements, reviews will be conducted to assess the effectiveness of the procedures against the objectives of the SWMP. This Plan will be revised due to: Deficiencies being identified. Extremes in environmental conditions. Improvements in knowledge or technological advancements. A change in the activities or operations associated with the Rasp Mine. Any amendments to the SWMP will be undertaken in consultation with the appropriate regulatory authorities and approved in the same manner as the initial SWMP. The Environmental Coordinator is responsible for the audit and review of the SWMP under any of the above triggers. Report No R-Rev11 51

57 16.0 REFERENCES Engineers Australia: Australian Rainfall and Runoff, 1998 John Miedecke and Partners: Stormwater Management Plan, report prepared in association with Water Studies Pty Ltd for Poseidon Mining Investments, October 1993 Landcom: Managing Urban Stormwater Soils and Construction Volume 1 4th Edition, March 2004 Local Government Act 1993 Environmental Planning and Assessment Act 1979 Department of Environment, Climate Change and Water (DECCW): Environmental Protection Licence No Protection of the Environment Operations Act 1997 Protection of the Environment Legislation Amendment Act 2011 Approved Methods for Sampling and Analysis of Water Pollutants in NSW (DEC) Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000) Managing Urban Stormwater: Soils & Construction (Landcom) Managing Urban Stormwater: Source Control (DECC) Technical Guidelines: Bunding & Spill Management (DECC) Report No R-Rev11 52

58 Report Signature Page GOLDER ASSOCIATES PTY LTD Louise McGinley Water Engineer Fred Gassner Principal LMcG/FWG/lmcg A.B.N Golder, Golder Associates and the GA globe design are trademarks of Golder Associates Corporation. j:\mining\2011\ rasp mine - site water\correspondence out\ r-rev11 site water management plan.docx Report No R-Rev11

59 N N6 m m m E m m N E5 35 E m 46 E m 0m N6 E m 30 0 E m m DRA WIN G TAK EN FRO M CBH RES OU RCE S DRG. No d wg DAT ED m 11 E C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. N6 46 N m LEGEND CML7 BOUNDARY KEY LAYOUT PLAN EXISTING DRAIN PROPOSED DRAIN EXISTING CULVERT MINE LEASE EXCLUSION AREA REHABILITATED AREAS PROPOSED CULVERT PROPOSED PIPE EXISTING PIPE SURFACE WATER POND PROPOSED BUND MINE WATER POND ELECTRICAL SUBSTATION SURFACE WATER FLOW ARROW PROPOSED VENT SHAFT MINE WATER FLOW ARROW PROPOSED SPILLWAY 0 CLIENT m PROJECT BROKEN HILL OPERATIONS PTY. LTD. AERIAL PHOTO, FILE NAMED RASP.ECW PROVIDED BY BROKEN HILL OPERATIONS PTY. LTD. DRAWING TAKEN FROM GEO-SPECTRUM (AUSTRALIA) PTY. LIMITED DRG. No. BHILL.dwg AERIAL PHOTOGRAPHY FLOWN 31st JANUARY 2000 CBH RESOURCES DRG. No dwg DATED PROCESS PLANT PROVIDED BY BROKEN HILL OPERATIONS ON 20 JULY 2011 (GRES_DES_MGA.STR), ALIGNED TO MGA :10,000 GOLDER ASSOCIATES PTY. LTD. DRAWN BY DATE MLL CHECKED BY DATE FWG SCALE OVERALL CATCHMENT AREAS SITE PLAN SHEET SIZE 1:10,000 RASP MINE - SURFACE WATER MANAGEMENT DRAWING TITLE A3 PROJECT No DOC No DOC TYPE 007 Plot Date: 24 April 2012 Time:10:45:52 AM By: Triffett, Dean Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F002-Rev4.dwg Xref: GAP_LOGO-A3.dwg; _XREF_CATCHMENT BOUNDARY-MGA94.dwg; XREF-10209_CBH_Rasp_Mine_HA_F_1.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-Plant Layout MGA94.dwg; XREF-SITE BOUNDARY AND EXCLUSION AREA-MGA94.dwg; XREF-HIGH RES IMAGE-MGA Z54.dwg; XREF-PROPOSED DRAINAGE-MGA94.dwg; RASP.ecw; R FIGURE No F002 REVISION 4 FIGURE 1

60 46 35 LEGEND 00 E m 0m N6 m CML7 BOUNDARY MINE LEASE EXCLUSION AREA REHABILITATED AREAS SURFACE WATER POND EXISTING DRAIN 49 PROPOSED DRAIN EXISTING CULVERT PROPOSED PIPE PROPOSED BUND PROPOSED SPILLWAY SURFACE WATER FLOW ARROW m m N6 E5 C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. E5 N m m 1:4,000 CLIENT PROJECT BROKEN HILL OPERATIONS PTY. LTD. AERIAL PHOTO, FILE NAMED RASP.ECW PROVIDED BY BROKEN HILL OPERATIONS PTY. LTD. DRAWING TAKEN FROM GEO-SPECTRUM (AUSTRALIA) PTY. LIMITED DRG. No. BHILL.dwg AERIAL PHOTOGRAPHY FLOWN 31st JANUARY 2000 CBH RESOURCES DRG. No dwg DATED PROCESS PLANT PROVIDED BY BROKEN HILL OPERATIONS ON 20 JULY 2011 (GRES_DES_MGA.STR), ALIGNED TO MGA94 GOLDER ASSOCIATES PTY. LTD. DRAWN BY DATE MLL CHECKED BY DATE FWG SCALE CATCHMENT AREA LAYOUT PLAN SOUTH WESTERN CATCHMENTS SHEET SIZE 1:4,000 RASP MINE - SURFACE WATER MANAGEMENT DRAWING TITLE A3 Plot Date: 24 April 2012 Time:10:48:14 AM By: Triffett, Dean Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F003-Rev5.dwg Xref: GAP_LOGO-A3.dwg; _XREF_CATCHMENT BOUNDARY-MGA94.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-Plant Layout MGA94.dwg; XREF-HIGH RES IMAGE-MGA Z54.dwg; XREF-PROPOSED DRAINAGE-MGA94.dwg; XREF-SITE BOUNDARY AND EXCLUSION AREA-MGA94.dwg; RASP.ecw; PROJECT No DOC No 007 DOC TYPE R FIGURE No F003 REVISION 5 FIGURE 2

61 C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. 0m 00 LEGEND m E5 m m N6 E5 N CML7 BOUNDARY MINE LEASE EXCLUSION AREA REHABILITATED AREAS SURFACE WATER POND MINE WATER POND EXISTING DRAIN PROPOSED DRAIN EXISTING CULVERT EXISTING PIPE PROPOSED PIPE PROPOSED BUND SURFACE WATER FLOW ARROW MINE WATER FLOW ARROW ELECTRICAL SUBSTATION PROPOSED VENT SHAFT PROPOSED SPILLWAY N m LINE PIPE LINE NT PIPE PLANT CESSS PLA PROCES PRO MINE DEWATERING DEWATERING U/G U/G MINE m 1:4,000 CLIENT PROJECT BROKEN HILL OPERATIONS PTY. LTD. AERIAL PHOTO, FILE NAMED RASP.ECW PROVIDED BY BROKEN HILL OPERATIONS PTY. LTD. DRAWING TAKEN FROM GEO-SPECTRUM (AUSTRALIA) PTY. LIMITED DRG. No. BHILL.dwg AERIAL PHOTOGRAPHY FLOWN 31st JANUARY 2000 CBH RESOURCES DRG. No dwg DATED PROCESS PLANT PROVIDED BY BROKEN HILL OPERATIONS ON 20 JULY 2011 (GRES_DES_MGA.STR), ALIGNED TO MGA94 GOLDER ASSOCIATES PTY. LTD. DRAWN BY DATE MLL CHECKED BY DATE FWG SCALE CATCHMENT AREA LAYOUT PLAN NORTH WESTERN CATCHMENTS SHEET SIZE 1:4,000 RASP MINE - SURFACE WATER MANAGEMENT DRAWING TITLE A3 Plot Date: 24 April 2012 Time:10:50:27 AM By: Triffett, Dean Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F004-Rev5.dwg Xref: GAP_LOGO-A3.dwg; _XREF_CATCHMENT BOUNDARY-MGA94.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-Plant Layout MGA94.dwg; XREF-HIGH RES IMAGE-MGA Z54.dwg; XREF-PROPOSED DRAINAGE-MGA94.dwg; XREF-SITE BOUNDARY AND EXCLUSION AREA-MGA94.dwg; RASP.ecw; PROJECT No DOC No 007 DOC TYPE R FIGURE No F004 REVISION 5 FIGURE 3

62 ST E-5 N 2 N RL SS E-5 M 6 N RL m m 46 m LEGEND E m N6 E5 N CML7 BOUNDARY REHABILITATED AREAS 5 SURFACE WATER POND TRACK CENTRES MINE WATER POND EXISTING DRAIN PROPOSED DRAIN PROPOSED CULVERT 1 PROPOSED PIPE PROPOSED BUND SURFACE WATER FLOW ARROW MINE WATER FLOW ARROW 3 PROPOSED SPILLWAY 4 DR A WIN G TA KE NF RO M CB H RE SO U RC E SD RG.N o d wg DA TE D N m 8 E m 9 C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. 6 MINE LEASE EXCLUSION AREA m 1:4,000 CLIENT PROJECT BROKEN HILL OPERATIONS PTY. LTD. AERIAL PHOTO, FILE NAMED RASP.ECW PROVIDED BY BROKEN HILL OPERATIONS PTY. LTD. DRAWING TAKEN FROM GEO-SPECTRUM (AUSTRALIA) PTY. LIMITED DRG. No. BHILL.dwg AERIAL PHOTOGRAPHY FLOWN 31st JANUARY 2000 CBH RESOURCES DRG. No dwg DATED PROCESS PLANT PROVIDED BY BROKEN HILL OPERATIONS ON 20 JULY 2011 (GRES_DES_MGA.STR), ALIGNED TO MGA94 GOLDER ASSOCIATES PTY. LTD. DRAWN BY DATE MLL CHECKED BY DATE FWG SCALE CATCHMENT AREA LAYOUT PLAN NORTH EASTERN CATCHMENTS SHEET SIZE 1:4,000 RASP MINE - SURFACE WATER MANAGEMENT DRAWING TITLE A3 PROJECT No DOC No DOC TYPE 007 Plot Date: Time:11:48:00 AM By: Lui Lam, Mitzi Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F005-Rev6.dwg Xref: GAP_LOGO-A3.dwg; _XREF_CATCHMENT BOUNDARY-MGA94.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-Plant Layout MGA94.dwg; XREF-10209_CBH_Rasp_Mine_HA_F_1.dwg; XREF-HIGH RES IMAGE-MGA Z54.dwg; XREF-PROPOSED DRAINAGE-MGA94.dwg; XREF-SITE BOUNDARY AND EXCLUSION AREA-MGA94.dwg; RASP.ecw; R FIGURE No F005 REVISION 6 FIGURE 4

63 CML7 BOUNDARY MINE LEASE EXCLUSION AREA REHABILITATED AREAS SURFACE WATER POND EXISTING DRAIN PROPOSED DRAIN EXISTING CULVERT EXISTING PIPE PROPOSED PIPE PROPOSED BUND N6 46 SURFACE WATER FLOW ARROW m PROPOSED SPILLWAY N6 25 m m 00 E m 46 E5 C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. LEGEND m 1:4,000 CLIENT PROJECT BROKEN HILL OPERATIONS PTY. LTD. AERIAL PHOTO, FILE NAMED RASP.ECW PROVIDED BY BROKEN HILL OPERATIONS PTY. LTD. DRAWING TAKEN FROM GEO-SPECTRUM (AUSTRALIA) PTY. LIMITED DRG. No. BHILL.dwg AERIAL PHOTOGRAPHY FLOWN 31st JANUARY 2000 CBH RESOURCES DRG. No dwg DATED PROCESS PLANT PROVIDED BY BROKEN HILL OPERATIONS ON 20 JULY 2011 (GRES_DES_MGA.STR), ALIGNED TO MGA94 GOLDER ASSOCIATES PTY. LTD. DRAWN BY DATE MLL CHECKED BY DATE FWG SCALE CATCHMENT AREA LAYOUT PLAN SOUTHERN CATCHMENTS SHEET SIZE 1:4,000 RASP MINE - SURFACE WATER MANAGEMENT DRAWING TITLE A3 PROJECT No DOC No DOC TYPE 007 Plot Date: 24 April 2012 Time:10:52:08 AM By: Triffett, Dean Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F006-Rev5.dwg Xref: GAP_LOGO-A3.dwg; _XREF_CATCHMENT BOUNDARY-MGA94.dwg; XREF-10209_CBH_Rasp_Mine_HA_F_1.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-Plant Layout MGA94.dwg; XREF-SITE BOUNDARY AND EXCLUSION AREA-MGA94.dwg; XREF-HIGH RES IMAGE-MGA Z54.dwg; XREF-PROPOSED DRAINAGE-MGA94.dwg; RASP.ecw; R FIGURE No F006 REVISION 5 FIGURE 5

64 LINEE PIPEE LIN NE PIP U/G U/G MI MINE LEGEND m CML7 BOUNDARY SHAFT ## 77 SHAFT MINE LEASE EXCLUSION AREA SURFACE WATER POND LINE TO TO PLANT PLANT SITE PIPE SITE PIPE LINE TSF TSF DECANT DAM DAM DECANT SHAFT SHAFT ## 77 PIPE PIPE LINE LINE MINE WATER POND EXISTING DRAIN U/G U/G MINE MINE DEWATERING DEWATERING PROPOSED DRAIN EXISTING CULVERT MINE WATER WATER PIPE PIPE LINE LINE RETURN RETURN MINE PROPOSED PIPE PROPOSED BUND SURFACE WATER FLOW ARROW MINE WATER FLOW ARROW PROPOSED SPILLWAY N m 20C E m m 20B E5 C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. N6 N m m 1:4,000 CLIENT PROJECT BROKEN HILL OPERATIONS PTY. LTD. AERIAL PHOTO, FILE NAMED RASP.ECW PROVIDED BY BROKEN HILL OPERATIONS PTY. LTD. DRAWING TAKEN FROM GEO-SPECTRUM (AUSTRALIA) PTY. LIMITED DRG. No. BHILL.dwg AERIAL PHOTOGRAPHY FLOWN 31st JANUARY 2000 CBH RESOURCES DRG. No dwg DATED PROCESS PLANT PROVIDED BY BROKEN HILL OPERATIONS ON 20 JULY 2011 (GRES_DES_MGA.STR), ALIGNED TO MGA94 GOLDER ASSOCIATES PTY. LTD. DRAWN BY DATE MLL CHECKED BY DATE FWG SCALE CATCHMENT AREA LAYOUT PLAN SOUTH EASTERN CATCHMENTS SHEET SIZE 1:4,000 RASP MINE - SURFACE WATER MANAGEMENT DRAWING TITLE A3 Plot Date: 24 April 2012 Time:10:55:39 AM By: Triffett, Dean Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F007-Rev5.dwg Xref: GAP_LOGO-A3.dwg; _XREF_CATCHMENT BOUNDARY-MGA94.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-Plant Layout MGA94.dwg; XREF-HIGH RES IMAGE-MGA Z54.dwg; XREF-PROPOSED DRAINAGE-MGA94.dwg; XREF-SITE BOUNDARY AND EXCLUSION AREA-MGA94.dwg; RASP.ecw; PROJECT No DOC No 007 DOC TYPE R FIGURE No F007 REVISION 5 FIGURE 6

65 LEGEND C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. DRAWING TAKEN FROM bhill_mine.dxf DATED JANUARY 2008 (AERIAL SURVEY OF JANUARY 2000 IN MINE GRID). SURVEY RE-CONTOURED IN TERRAMODEL ( _TM_004.PRO) AND ALIGNED TO MGA94 Plot Date: 28 October 2011 Time:3:27:09 PM By: Lui Lam, Mitzi Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F008-Rev2.dwg Xref: GAP_LOGO-A3.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-Base Contours 2m spacing 750 label spacing.dwg; GOLDER ASSOCIATES PTY. LTD. CLIENT BROKEN HILL OPERATIONS PTY. LTD. DRAWN BY CHECKED BY SCALE DATE LMcG/MLL DATE FWG :1,000 A3 PROJECT DRAWING TITLE 1:1,000 MAXIMUM WATER STORAGE AREA AT ELEVATION 299.0m (AHD) OF HORWOOD DAM MAXIMUM WATER STORAGE AREA AT ELEVATION 297.5m (AHD) FOR 100 YEAR ARI EXISTING CONTOUR (2m INTERVALS) m RASP MINE - SURFACE WATER MANAGEMENT HORWOOD DAM STORAGE AREAS SHEET SIZE PROJECT No DOC No DOC TYPE FIGURE No REVISION R F008 2 FIGURE 7

66 C GOLDER ASSOCIATES PTY. LTD. INFORMATION CONTAINED ON THIS DRAWING IS THE COPYRIGHT OF GOLDER ASSOCIATES PTY. LTD. UNAUTHORISED USE OR REPRODUCTION OF THIS PLAN EITHER WHOLLY OR IN PART WITHOUT WRITTEN PERMISSION INFRINGES COPYRIGHT. E m N m N m LEGEND N m EXISTING GROUNDWATER MONITORING BORE LOCATIONS PROPOSED GROUNDWATER MONITORING BORE LOCATIONS E m DRAWING TAKEN FROM bhill_mine.dxf DATED JANUARY 2008 (AERIAL SURVEY OF JANUARY 2000 IN MINE GRID). SURVEY RE-CONTOURED IN TERRAMODEL ( _TM_004.PRO) AND ALIGNED TO MGA94 N m E m E m N m GOLDER ASSOCIATES PTY. LTD. Plot Date: 19 March 2012 Time:11:20:28 AM By: Lui Lam, Mitzi Path: J:\Mining\2011\ Rasp Mine - Site Water\Technical Doc\CADD\FIGURES - File Name: R-F001-Rev6.dwg Xref: GAP_LOGO-A3.dwg; XREF-Plant Layout MGA94.dwg; XREF-Base Contours 2m spacing 750 label spacing.dwg; _XREF_Rasp Mine Base Survey MGA94.dwg; XREF-GOOGLE EARTH-MGA Z54.dwg; _XREF_CATCHMENT BOUNDARY-MGA94.dwg; CLIENT DRAWN BY CHECKED BY SCALE E m BROKEN HILL OPERATIONS PTY. LTD. DATE JGG/MLL DATE FWG :10,000 A3 N m PROJECT DRAWING TITLE 1:10,000 E m RASP MINE - SURFACE WATER MANAGEMENT PROPOSED GROUNDWATER MONITORING BORE LOCATIONS SHEET SIZE PROJECT No DOC No DOC TYPE FIGURE No REVISION E m E m m R F001 6 FIGURE 8

67 APPENDIX A Australian Water Quality Centre Analytical Report 31/08/2011 Amdel Ltd Analytical Report 24/05/2007 Report No R-Rev11

68 BH Operations ATTN: Darren Zanette PO Box 5073 Broken Hill NSW 2880 AUSTRALIA 31/08/2011 Dear Darren Please find attached the Final Analytical Report for Customer Service Request: CSR-2 Account: Project: AWQC BH Operations - Non Routine 11/12 Please note AWQC Sample Receipt hours are Monday to Friday 8.30am pm. Yours sincerely, Sam Loveder Senior Customer Service Officer Sam.Loveder@sawater.com.au ABN Page 1 of 6 A business unit of the South Australian Water Corporation

69 FINAL REPORT: Report Information Customer Project Name CSR_ID Analytical Results Customer Sample Description Sampling Point Sampled Date Sample Received Date Sample ID Status Collection Type BH Operations AWQC CSR-2 Sample 1-7 Water BH Operations 11/08/2011 8:30:00AM 22/08/2011 2:26:36PM * Endorsed Customer Collected Inorganic Chemistry - Metals LOR Result Aluminium - Soluble TIC-003 W Aluminium - Soluble mg/l Aluminium - Total TIC-003 W Aluminium - Total mg/l Arsenic - Soluble TIC-003 W Arsenic - Soluble mg/l Arsenic - Total TIC-003 W Arsenic - Total mg/l Cadmium - Soluble TIC-004 W Cadmium - Soluble mg/l Cadmium - Total TIC-004 W Cadmium - Total mg/l Calcium TIC-004 W Calcium mg/l Copper - Soluble TIC-003 W Copper - Soluble mg/l Copper - Total TIC-003 W Copper - Total mg/l Dissolved Solids by Calculation W Dissolved solids by calculation mg/l Ion Balance W Ion balance -6.3 % Iron - Soluble TIC-003 W Iron - Soluble mg/l Iron - Total TIC-003 W Iron - Total mg/l Langelier Index W Langelier Index -1.9 Lead - Soluble TIC-004 W Lead - Soluble mg/l Lead - Total TIC-004 W ABN Corporate Accreditation No.1115 Chemical and Biological Testing This document is issued in accordance with NATA's accreditation requirements. Notes 1. The last figure of the result value is a significant figure. 2. Samples are analysed as received. 3. # determination of the component is not covered by NATA Accreditation. 4. ^ indicates result is out of specification according to the reference Guideline. Refer to Report footer. 5. * indicates incident have been recorded against the sample. Refer to Report footer. 6. & Indicates the results have changed since the last issued report. 7. The Limit of Reporting (LOR) is the lowest concentration of analyte which is reported at the AWQC and is based on the LOQ rounded up to a more readily used value. The Limit of Quantitation (LOQ) is the lowest concentration of analyte for which quantitative results may be obtained within a specified degree of confidence. Page 2 of 6 A business unit of the South Australian Water Corporation

70 FINAL REPORT: Analytical Results Customer Sample Description Sampling Point Sampled Date Sample Received Date Sample ID Status Collection Type Sample 1-7 Water BH Operations 11/08/2011 8:30:00AM 22/08/2011 2:26:36PM * Endorsed Customer Collected Lead - Total TIC-004 W Lead - Total mg/l Magnesium TIC-004 W Magnesium mg/l Manganese - Soluble TIC-004 W Manganese - Soluble mg/l Manganese - Total TIC-004 W Manganese - Total mg/l Potassium TIC-003 W Potassium mg/l Sodium Adsorption Ratio W Sodium Adsorption Ratio - Calculation 29.2 Sodium TIC-004 W Sodium mg/l Sulphur TIC-004 W Sulphate mg/l Total Hardness as CaCO3 W Total Hardness as CaCO mg/l Zinc - soluble TIC-004 W Zinc - Soluble mg/l Zinc - Total TIC-004 W Zinc - Total mg/l Inorganic Chemistry - Nutrients LOR Result Chloride T W Chloride mg/l Fluoride W Fluoride mg/l Nitrate + Nitrite as N T W Nitrate + Nitrite as N mg/l Inorganic Chemistry - Physical LOR Result Alkalinity Carbonate Bicarbonate and Hydroxide T W Alkalinity as Calcium Carbonate Bicarbonate Carbonate Hydroxide 18 mg/l 22 mg/l 0 mg/l 0 mg/l ABN Corporate Accreditation No.1115 Chemical and Biological Testing This document is issued in accordance with NATA's accreditation requirements. Notes 1. The last figure of the result value is a significant figure. 2. Samples are analysed as received. 3. # determination of the component is not covered by NATA Accreditation. 4. ^ indicates result is out of specification according to the reference Guideline. Refer to Report footer. 5. * indicates incident have been recorded against the sample. Refer to Report footer. 6. & Indicates the results have changed since the last issued report. 7. The Limit of Reporting (LOR) is the lowest concentration of analyte which is reported at the AWQC and is based on the LOQ rounded up to a more readily used value. The Limit of Quantitation (LOQ) is the lowest concentration of analyte for which quantitative results may be obtained within a specified degree of confidence. Page 3 of 6 A business unit of the South Australian Water Corporation

71 FINAL REPORT: Analytical Results Customer Sample Description Sampling Point Sampled Date Sample Received Date Sample ID Status Collection Type Sample 1-7 Water BH Operations 11/08/2011 8:30:00AM 22/08/2011 2:26:36PM * Endorsed Customer Collected Conductivity & Total Dissolved Solids T W Conductivity µscm Total Dissolved Solids (by EC) mg/l ph T W ph 5.8 ph units ABN Corporate Accreditation No.1115 Chemical and Biological Testing This document is issued in accordance with NATA's accreditation requirements. Notes 1. The last figure of the result value is a significant figure. 2. Samples are analysed as received. 3. # determination of the component is not covered by NATA Accreditation. 4. ^ indicates result is out of specification according to the reference Guideline. Refer to Report footer. 5. * indicates incident have been recorded against the sample. Refer to Report footer. 6. & Indicates the results have changed since the last issued report. 7. The Limit of Reporting (LOR) is the lowest concentration of analyte which is reported at the AWQC and is based on the LOQ rounded up to a more readily used value. The Limit of Quantitation (LOQ) is the lowest concentration of analyte for which quantitative results may be obtained within a specified degree of confidence. Page 4 of 6 A business unit of the South Australian Water Corporation

72 FINAL REPORT: NATA Signatories Dzung Bui - Inorganic Chemistry Team Leader Joanne Clark - Inorganic Chemistry Team Leader ABN Corporate Accreditation No.1115 Chemical and Biological Testing This document is issued in accordance with NATA's accreditation requirements. Notes 1. The last figure of the result value is a significant figure. 2. Samples are analysed as received. 3. # determination of the component is not covered by NATA Accreditation. 4. ^ indicates result is out of specification according to the reference Guideline. Refer to Report footer. 5. * indicates incident have been recorded against the sample. Refer to Report footer. 6. & Indicates the results have changed since the last issued report. 7. The Limit of Reporting (LOR) is the lowest concentration of analyte which is reported at the AWQC and is based on the LOQ rounded up to a more readily used value. The Limit of Quantitation (LOQ) is the lowest concentration of analyte for which quantitative results may be obtained within a specified degree of confidence. Page 5 of 6 A business unit of the South Australian Water Corporation

73 FINAL REPORT: Incidents Sample ID S.Point Description Analysis (where Sampled Date Applicable) Incident Description Sample 1-7 Water 11/08/2011 Cadmium - Soluble Soluble result > Total result Analytical Method Analytical Method Code Description T Determination of ph T Determination of Conductivity T Alkalinity - Automated Acidimetric Titration T Chloride - Automated Flow Colorimetry T Nitrate + Nitrate (NOx) - Automated Flow Colorimetry TIC-003 Elemental Analysis - ICP Mass Spectrometry TIC-004 Determination of Metals - ICP Spectrometry by ICP2 W-052 Preparation of Samples for Metal Analysis Sampling Method Sampling Method Code Description W Sampling Method for Chemical Analyses Laboratory Information Laboratory Inorganic Chemistry - Metals Inorganic Chemistry - Nutrients Inorganic Chemistry - Physical NATA accreditation ID ABN Corporate Accreditation No.1115 Chemical and Biological Testing This document is issued in accordance with NATA's accreditation requirements. Notes 1. The last figure of the result value is a significant figure. 2. Samples are analysed as received. 3. # determination of the component is not covered by NATA Accreditation. 4. ^ indicates result is out of specification according to the reference Guideline. Refer to Report footer. 5. * indicates incident have been recorded against the sample. Refer to Report footer. 6. & Indicates the results have changed since the last issued report. 7. The Limit of Reporting (LOR) is the lowest concentration of analyte which is reported at the AWQC and is based on the LOQ rounded up to a more readily used value. The Limit of Quantitation (LOQ) is the lowest concentration of analyte for which quantitative results may be obtained within a specified degree of confidence. Page 6 of 6 A business unit of the South Australian Water Corporation

74 This document is issued in accordance with NATA's accreditation requirements. Accredited for compliance with ISO/IEC Accreditation Number: 1645 Broken Hill Operations Pty Ltd P O Box 5073 Broken Hill NSW 2880 Australia Certificate of Analysis Attention: Robert Ogden Project 07ENME Order Number R0-206 Customer Sample ID 5 LITRE CONTAINER Amdel Sample Number Date Sampled 24/05/2007 Metals Test/Reference PQL Unit 3100 Dissolved Metals in Water By ICP/MS Aluminium 5 µg/l 31 Copper 5 µg/l 65 Lead 5 µg/l 50 Manganese 5 µg/l Zinc 5 µg/l Dissolved Metals in Water - ICP/AES Calcium 100 µg/l Iron 100 µg/l 252 Silicon 100 µg/l Sodium 100 µg/l Inorganics Test/Reference PQL Unit 4550 Alkalinity in Water Total Alkalinity as CaCO3 20 mg/l ph in Water ph 0.1 ph Total Dissolved Solids in Water 4100 Total Dissolved Solids in Water 5 mg/l Anions in Water by IC Chloride 0.5 mg/l 1500 Fluoride 0.5 mg/l 7.7 Nitrate 0.5 mg/l <0.5 Nitrite 0.5 mg/l <0.5 Sulphate 0.5 mg/l 4300 Sample History Where samples are submitted/analysed over several days, the last date of extraction and analysis is reported. Description Extracted Analysed 3100 Dissolved Metals in Water By ICP/MS 13/06/ /06/ Dissolved Metals in Water - ICP/AES 13/06/ /06/ ph in Water 13/06/ /06/ Total Dissolved Solids in Water 13/06/ /06/ Anions in Water by IC 21/06/ Alkalinity in Water 14/06/2007 First Reported: 21 June 2007 Amdel Ltd 1868 Dandenong Rd Clayton VIC Australia 3168 Page 1 of 3 Date Printed: 21 June 2007 ABN: Telephone: (03) Facsimile: (03) Report Number:

75 Amdel Internal Quality Control Review General 1. Laboratory QC results for Method Blanks, Duplicates, Matrix Spikes, and Laboratory Control Samples are included in this QC report where applicable. Additional QC data may be available on request. 2. Amdel QC Acceptance/Rejection criteria are available on request. 3. Proficiency trial results are available on request. 4. Actual PQLs are matrix dependant. Quotes PQLs may be raised where sample extracts are diluted due to interferences. 5. Results are uncorrected for matrix spike or surrogate recoveries. 6. Test samples duplicated or spiked, are for this job only and are identified in the following QC report. 7. SVOC analyses on waters are performed on homogenized, unfiltered sample, unless noted otherwise. 8. When individual results are qualified in the body of a report, refer to the qualifier descriptions that follow. Holding Times Please refer to 'Sampling and Preservation Chart for Soils & Waters' for holding times. (Amdel form AD-FOR_ADM-020) For samples received on the last day of holding time, notification of testing requirements should have been received at least 6 hours prior to sample receipt deadlines as stated on the Sample Receipt Acknowledgement. If the Laboratory did not receive the information in the required timeframe, and regardless of any other integrity issues, suitablity qualified results may still be reported. Holding times apply from the date of sampling, therefore compliance to these may be outside the laboratory's control. Quality Control Results Laboratory: EN_METALS Sample, Test, Result Reference [ Method Blank ] 3100 Dissolved Metals in Water By ICP/MS Units Result 1 Acceptance Limits Copper µg/l <5 < 5 T Lead µg/l <5 < 5 T Manganese µg/l <5 < 5 T Zinc µg/l <5 < 5 T [ Method Blank ] 3200 Dissolved Metals in Water - ICP/AES Calcium µg/l <100 < 100 T Iron µg/l <100 < 100 T Sodium µg/l <100 < 100 T [ Laboratory Control Sample ] 3100 Dissolved Metals in Water By ICP/MS Expected Value Percent Recovery Copper µg/l % T Lead µg/l % T Manganese µg/l % T Zinc µg/l % T Laboratory: EN_WATERS Sample, Test, Result Reference [ Method Blank ] 4300 Anions in Water by IC Units Result 1 Acceptance Limits Bromide mg/l <0.5 < 0.5 T Chloride mg/l <0.5 < 0.5 T Fluoride mg/l <0.5 < 0.5 T Nitrate mg/l <0.5 < 0.5 T Nitrite mg/l <0.5 < 0.5 T Phosphate mg/l <0.5 < 0.5 T Sulphate mg/l < 0.5 T Pass Limits Pass Limits Qualifying Codes Qualifying Codes First Reported: 21 June 2007 Amdel Ltd 1868 Dandenong Rd Clayton VIC Australia 3168 Page 2 of 3 Date Printed: 21 June 2007 ABN: Telephone: (03) Facsimile: (03) Report Number:

76 Laboratory: EN_WATERS Sample, Test, Result Reference [ Laboratory Control Sample ] Units Result Alkalinity in Water Expected Value Percent Recovery Acceptance Limits Bicarbonate as CaCO3 mg/l < % F Carbonate as CaCO3 mg/l % T Hydroxide as CaCO3 mg/l % F Total Alkalinity as CaCO3 mg/l % T [ Laboratory Control Sample ] 4300 Anions in Water by IC Expected Value Percent Recovery Bromide mg/l % T Chloride mg/l % T Fluoride mg/l % T Nitrate mg/l % T Nitrite mg/l % T Phosphate mg/l % T Sulphate mg/l % T Pass Limits Qualifying Codes Sample Integrity Attempt to Chill was evident Samples correctly preserved Samples received within HoldingTime Some samples have been subcontracted Yes Yes Yes No Authorised By Vanda Dabkowski Mark Herbstreit Helen Lei Customer Service Leader Senior Analyst Senior Analyst Accreditation Number: 1645 Accreditation Number: 1645 Laboratory Manager Anthony Crane Operations Manager Final Report - Indicates Not Requested * Indicates NATA accreditation does not cover the performance of this service Amdel Limited shall not be liable for loss, cost, damages or expenses incurred by the client, or any other person or company, resulting from the use of any information or interpretaton given in this report. In no case shall Amdel Limited be liable for consequential damages including, but not limited to, lost profits, damages for failure to meet deadlines and lost production arising from this report. This document shall not be reproduced except in full and relates only to the items tested. Unless indicated otherwise, the tests were performed on the samples as received. The samples were not collected by Amdel staff. First Reported: 21 June 2007 Amdel Ltd 1868 Dandenong Rd Clayton VIC Australia 3168 Page 3 of 3 Date Printed: 21 June 2007 ABN: Telephone: (03) Facsimile: (03) Report Number:

77 APPENDIX B Rasp Mine Water Management Strategy Report No R-Rev11

78 Rasp Mine Water Balance (Year 5) Lower water table Groundwater (7#) Raw water supply (kl) extra pump 7# (kl) inflow (kl) TSF seepage (kl) Ventilation losses Potable water to Plant (kl) Water in concentrate (kl) Evaporation (kl) TSF seepage (kl) 50, ,680 95,000 7,305 47,000 4,400 10,942 82,418 82,348 7,305 Concentrate (dry tonnes) Raw water (kl) Water in tailings (kl) Raw Water (kl) 50, ,153 0 Ore (dry tonnes) Tailings (dry tonnes) Reclaimed Water (kl) Closed circuit service water 650, , ,376 Rain (kl) 18,429 Diesel exhaust (kl) Water in ore (kl) 1,600 20,103 PROCESS PLANT TAILINGS DAM UNDERGROUND MINE Backfill (dry tonnes) 119,700 Reclaimed water (kl) 63,894 Water contained in backfill (kl) Excess UG water 42,057 for mill (kl) 158,022 Raw water (kl) 24,517 26, , ,035 Total shaft and mine extraction 309,056 kl per annum Water retained in backfill (kl) Dust suppression (kl) Backfill (dry tonnes) Reclaim for TSF Water retained in tailings (kl) Plus contingency for wet years haul roads & stockpiles 42,057 dust suppression (nominally 20%) kl per annum Water contained in backfill (kl) Total water extraction 370,867 kl per annum 370 ML Potable Water requirements (mining) (kl) 9,098 (Includes showers, toilets/laundry) Raw Water requirements (mining) (kl) 2,144 (Includes workshop & vehicle washbay) RASP PROJECT WATER BALANCE MODEL JULY 2011 Sum in 249,642 Sum in 297,232 Sum in 236,582 Sum out 249,642 Sum out 297,232 Sum out 236,582 SCHEMATIC YEAR 5

79 Golder Associates Pty Ltd Building 7, Botanicca Corporate Park Swan Street Richmond, Victoria 3121 Australia T: