CHAPTER 12 WATER VALUES AND QUALITY GULF ALUMINA LTD SKARDON RIVER BAUXITE PROJECT

Transcription

1 CHAPTER 12 WATER VALUES AND QUALITY GULF ALUMINA LTD SKARDON RIVER BAUXITE PROJECT

2 TABLE OF CONTENTS 12.1 Introduction Environmental Objectives and Performance Outcomes Environmental Objectives Performance Outcomes Legislative and Policy Context Environmental Protection Act Environmental Protection (Water) Policy (2009) Water Quality Guidelines Model Mining Conditions Environmental Authority Environmental Values Catchments and Watercourses Wetlands Water Quality Objectives Environmental Values from EPP Water Water Quality Objectives Surface Water Monitoring Surface Water Monitoring Locations Surface Water Level Data Surface Water Quality Physical Parameters Metals Nutrients Groundwater Monitoring Groundwater Monitoring Locations and Parameters Groundwater Levels Groundwater Quality Physical Parameters Metals Nutrients Potential Impacts, Emissions and Releases Mitigation and Management Measures Mine Pits Mine Site Sediment Management Mine Site Sediment Pond Management Port Infrastructure Area Bauxite Stockpile Sediment Control Contaminant Management Release Monitoring Effluent Irrigation Area Erosion and Sediment Control Erosion and Sediment Control Plan Permanent Haul Roads Namaleta Creek Crossing Location Existing Crossing Crossing Design Crossing Drainage Page 12-i

3 Crossing Construction and Rehabilitation Crossings of other Drainage Features Proposed Surface Water and Groundwater Monitoring Programme Surface Water Monitoring Locations Surface Water Monitoring Frequency and Parameters Surface Water Monitoring and Reporting Receiving Environment Monitoring Programme Groundwater Monitoring Saline Water Ingress Targeted Monitoring Bores Groundwater Monitoring and Reporting Bore Construction Risk Assessment Cumulative Impacts Conclusion Tables Table 12-1 Water Quality Trigger Values AWQG, Model Mining Conditions, Existing EA and Site Monitoring Data Table 12-2 Nominated Water Quality Objectives Table 12-3 Surface Water Monitoring Data Table 12-4 Surface Water Levels Table 12-5 Surface Water Physical Parameter Summary Results Namaleta Creek Table 12-6 Surface Water Physical Parameter Summary Results Wetlands Table 12-7 Surface Water Physical Parameter Summary Results Kaolin Water Storages Table 12-8 Surface Water Dissolved Metals Summary Results Namaleta Creek Table 12-9 Surface Water Dissolved Metals Summary Results Wetlands Table Surface Water Dissolved Metals Summary Results Kaolin Water Storages Table Surface Water Nutrient Summary Results Namaleta Creek Table Surface Water Nutrient Summary Results - Wetlands Table Surface Water Nutrient Summary Results - Kaolin Water Storages Table Groundwater Monitoring Data Table Groundwater Level Data Table Groundwater Physical Parameter Summary Results All Bores Table Groundwater Physical Parameter Summary Results Bulimba Formation (Namaleta Creek) Aquifer Table Groundwater Physical Parameter Summary Results Bulimba Formation Aquifer Table Groundwater Physical Parameter Summary Results Rolling Downs Siltstone Aquifer Table Groundwater Dissolved Metals Summary Results All Bores Table Groundwater Dissolved Metals Summary Results Bulimba Formation (Namaleta Creek) Aquifer Table Groundwater Dissolved Metals Summary Results Bulimba Formation Aquifer Table Groundwater Dissolved Metals Summary Results Rolling Downs Siltstone Aquifer Table Groundwater Nutrient Summary Results All Bores Page 12-ii

4 Table Groundwater Nutrient Summary Results Bulimba Formation (Namaleta Creek) Aquifer Table Groundwater Nutrient Summary Results Bulimba Formation Aquifer Table Groundwater Nutrient Summary Results Rolling Downs Siltstone Aquifer Table Catchments Areas, Sediment Runoff and Pond/Dam Sizing Table Release Points Port Area Sediment Ponds Table Release Limits Table Existing and Proposed Surface Water Monitoring Network Table Surface Water Monitoring Frequency and Parameters Table Groundwater Monitoring Network Table Risk Assessment and Management Measures for Impacts to Water Quality Figures Figure 12-1 Regional Catchments Figure 12-2 Local Catchments Figure 12-3 Wetlands Queensland WetlandInfo Mapping Figure 12-4 Wetlands of Namaleta Creek Catchment - Queensland WetlandInfo Mapping Figure 12-5 Referrable Wetlands Wetland Management Areas Figure 12-6 Vegetation Management Act Wetlands and Watercourses Figure 12-7 Directory of Important Wetlands Figure 12-8 Surface Water Monitoring Locations Figure 12-9 Site S8 Surface Water Level and Rainfall Figure Groundwater Monitoring Locations Figure Standing Groundwater Level Bore C Figure Standing Groundwater Level Bore G Figure Port Area Sediment Ponds and Drainage Figure Namaleta Creek Crossing Location Figure Namaleta Creek Crossing Downstream View Figure Haul Road Crossing of Drainage Feature Figure Existing and Proposed Monitoring Bores Figure Conceptual Mine Plan Bauxite Hills Project Page 12-iii

5 12. WATER VALUES AND QUALITY 12.1 Introduction This chapter describes the surface water environment, including catchments and wetlands, within and surrounding the Project area, describes surface water quality and groundwater quality from field samples, establishes environmental values and water quality objectives for waters in the Project area, describes potential impacts to water quality, proposes measures to mitigate impacts and provides a risk assessment for residual impacts. Information in this chapter is primarily based on the information provided in Appendix 4. Chapter 14 describes flood modelling and potential impacts from flooding from watercourses on the Project. Chapter 13 describes the surface water and groundwater hydrological and hydrogeological regimes of the Project, potential impacts and mitigation measures Environmental Objectives and Performance Outcomes The environmental objectives and performance outcomes below are based on Schedule 5, Table 2 of the Environmental Protection Regulations 2008 (EP Regulation). The mitigation and management measures presented in this chapter are designed to achieve these environmental objectives and performance outcomes. The environmental management plan (EM Plan) presented in Appendix 13 provides a consolidated description of these mitigation and management measures Environmental Objectives The activity will be operated in a way that protects environmental values of waters. The activity will be operated in a way that protects the environmental values of wetlands. The activity will be operated in a way that protects the environmental values of groundwater and any associated surface ecological systems. The choice of the site, at which the activity is to be carried out, minimises serious environmental harm on areas of high conservation value and special significance and sensitive land uses at adjacent places. The design of water management infrastructure is in accordance with best practice environmental management Performance Outcomes Contingency measures will prevent or minimise adverse effects on the environment due to unplanned releases or discharges of contaminants to water. The activity will be managed so that stormwater contaminated by the activity that may cause an adverse effect on an environmental value will not leave the site without prior treatment. Any discharge to water or a watercourse or wetland will be managed so that there will be no adverse effects due to the altering of existing flow regimes for water or a watercourse or wetland. The activity will be managed so that adverse effects on environmental values are prevented or minimised. Page 12-1

6 The activity will be managed in a way that prevents or minimises adverse effects on wetlands. The activity will be managed to prevent or minimise adverse effects on groundwater or any associated surface ecological systems. The activity will be managed to prevent or minimise adverse effects on the environmental values of land due to unplanned releases or discharges. Areas of high conservation value and special significance likely to be affected by the proposal are identified and evaluated and any adverse effects on the areas are minimised, including any edge effects on the areas Legislative and Policy Context Environmental Protection Act 1994 The Environmental Protection Act 1994 (EP Act) provides for environmental protection policies that establish the environmental values (EVs) which are to be protected, that include quality standards that are relevant to the water environment. The EVs of waterways in Queensland (including groundwater) are protected under the EP Act and the subordinate Environmental Protection (Water) Policy 2009 (EPP Water) Environmental Protection (Water) Policy (2009) The EPP Water establishes a process for identifying environmental values to be protected and states standards for water quality in support of those values. This policy is supported by the Queensland Water Quality Guidelines 2009 (QWQG). The EPP Water provides a framework for the following: Identifying environmental values and management goals for Queensland waters. Stating water quality guidelines and objectives to enhance the environmental values. Providing a framework for making consistent, equitable and informed decisions about Queensland waters. Monitoring and reporting on the condition of Queensland waters. The EPP Water has been established to protect Queensland waters while allowing for ecologically sustainable development. The purpose of the policy is to identify EVs for aquatic ecosystems and for human uses; and determine water quality guidelines and water quality objectives to protect EVs. Aquatic ecosystems in both surface and groundwater habitats have EVs that require certain levels of protection under the EPP Water. EVs and water quality objectives have been established for many waterways in Queensland under Schedule 1 of the EPP Water. Environmental values and associated water quality objectives have not been established for the rivers in Cape York potentially impacted by the Project. The EPP Water defines an indicator for an EV as a property that can be measured or decided in a quantitative way. Water quality objectives are numerical concentrations or statements for indicators that protect a stated environmental value and are generally developed based on the review of the available site-specific information relevant to each environmental value Water Quality Guidelines The Australian and New Zealand Environment and Conservation Council (ANZECC) has developed the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC & ARMCANZ 2000) Page 12-2

7 (hereafter referred to as the Australian Water Quality Guidelines (AWQG)). The AWQG are numerical concentration limits or descriptive statements that can be applied to a range of ecosystem types and water uses, such as recreational and stock water. Water quality guidelines give recommended values for indicators and are designed to ensure that EVs of waters are protected. The need to develop guidelines for specific regions, water types and local flora and fauna is one of the main reasons why the QWQGs were developed. Section 4 of the QWQG recommends the use of local water quality objectives developed for appropriate indicators / parameters using monitoring data from local reference sites. The QWQG stipulates a minimum set of eight independent surveys over 12 months from each reference site to establish interim local water quality objectives, and a further 10 independent surveys over the next 12 month to establish local water quality objectives where there are two or less reference sites. Where there are three or more reference sites, a further four independent surveys over the next 12 months are needed to establish local water quality objectives. A reference site is defined as a site whose condition is considered to be a suitable baseline or benchmark for assessment and management of sites in similar water bodies. The water quality objective is then determined using the 20th and 80th percentile, as appropriate, for each parameter from these independent survey data Model Mining Conditions The model mining conditions are a set of model conditions to form general environmental protection commitments given for mining activities, and environmental authority conditions for resource activities imposed by the administering authority under the EP Act. These model conditions have been used as a guide for developing environmental protection commitments relating to water management and for appropriate conditions for an environmental authority for the Project Environmental Authority Gulf has an existing environmental authority (EA) issued for the kaolin mine which has ceased operations. This EA governs the ongoing rehabilitation, decommissioning and management of the kaolin mine, formerly a Level 1 mining project on the Mining Leases ML 6025, ML and ML Gulf recognises that the existing EA (including conditions related to water management) will be amended as an outcome of the EIS process. The current EA addresses the following areas relevant to water management for the kaolin mine: Requirement for monitoring receiving waters affected by the release of process water or stormwater contaminated by kaolin mining activities. Prohibition of waste deposition and the release of Acid Sulphate Soils (ASS) to any waters. Monitoring locations and frequencies (receiving waters, end of pipe discharge, groundwater affected by kaolin mining activities). Contaminant release limits for end of pipe discharges, sewage effluent for irrigation, and groundwater. Contaminant trigger limits for receiving water and groundwater. Conditions for use of sewage effluent for irrigation. Requirement for sampling methods to comply with those set out in the latest edition of the Environmental Protection Agency s Water Quality Sampling Manual. It is expected that the amended EA will retain relevant sections related to approval conditions for the kaolin mine as these decommissioning and rehabilitation activities will be ongoing. Page 12-3

8 12.4 Environmental Values Catchments and Watercourses The Project is situated in the tropics and experiences high rainfall during the wet season and hot, humid conditions during the dry season. In normal years, up to 80 per cent of average annual rainfall occurs as a result of tropical cyclonic events during the wet seasonal months of December to mid-april. However, in exceptionally dry years, rainfall during the wet season months can account for between 80 and 90% of the annual precipitation. The Project s mining leases are primarily drained by two drainages the Skardon River and Namaleta Creek. Regional catchments on Cape York surrounding the Project area are shown in Figure The catchments for the Skardon River and Namaleta Creek are shown in Figure In addition there are highly localised drainages to the west of the mining leases, which drain the areas between the mining leases and the beach ridges, as shown in Figure 12-2 (catchments 1, 2, 3 and 4). The northern end of the Project is bounded by the Skardon River which drains mangrove areas through three primary tributaries to the south and east. The Skardon River is considered a predominantly estuarine system, consisting of freshwater systems within its upper reaches. The Skardon River catchment is approximately 480 km 2, which is relatively small compared to other catchments on Cape York. The southern tributary of the Skardon River catchment (Catchment 7 in Figure 12-2) is approximately km 2. Estuarine conditions continue upstream into the southern tributary (Skardon River South Arm) for approximately 9.3 km from its confluence with the main Skardon River Estuary. In the Project area, areas of mining are within the catchment of this estuarine reach of the Skardon River only (i.e. they are not within the catchments of the freshwater parts of the Skardon River). Namaleta Creek is a localised drainage with a catchment of 37 km 2, of which 21 km 2 lies upstream of the eastern mine boundary. This watercourse is tidally influenced, where mangrove communities begin approximately 1 km west (downstream) of the existing crossing of Namaleta Creek. The ephemeral system rises from the north and east and eventually discharges to the south into Port Musgrave. Page 12-4

9 ML 6025 ML ML COX CAIRNS ± TORRES STRAIT ISLANDS SUB-BASIN Queensland TOWNSVILLE ROCKHAMPTON JACKEY JACKEY CREEK BRISBANE DOUGHBOY RIVER JARDINE RIVER SUB-BASIN JARDINE MCHENRY RIVER JACKSON RIVER MCDONALD RIVER SUB-BASIN ELIOT CREEK RIVER COCKATOO CREEK SKARDON RIVER SKARDON RIVER SUB-BASIN DULHUNTY RIVER NORTH ALICE CREEK CHOLMONDELEY CREEK JACKY JACKY CREEK SUB-BASIN HARMER CREEK DUCIE RIVER DUCIE/DULHUNTY RIVER SUB-BASIN PALM CREEK OLIVE RIVER OLIVE RIVER SUB-BASIN WATSON RIVER SUB-BASIN MISSION RIVER SUB-BASIN EMBLEY RIVER MISSION RIVER EMBLEY RIVER SUB-BASIN KURRACOO CREEK CREEK MYALL CREEK WENLOCK RIVER SUB-BASIN Kilometers HESKET CREEK RIVER ROCKY WENLOCK CREEK PASCOE RIVER GLENNIE CREEK PASCOE RIVER SUB-BASIN Sources: Esri, USGS, NOAA Legend Mining Lease Boundaries Major Watercourses River Sub-Basins Figure 12-1 Regional Catchments Gulf Alumina Limited Date: 15/08/2015 Revision: R1 Author: malcolm.nunn Map Scale: 1:1,000,000 Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_SurfaceWater\FIG_12_01_Regional_Catchments_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Drainage basins State of Queensland (DNRM 2015).

10 ± CAIRNS Queensland TOWNSVILLE ROCKHAMPTON BRISBANE SKARDON RIVER ML ML ( Bigfoot Swamp Lunette Swamp ML NAMALETA CREEK NAMALETA CREEK NAMALETA CREEK DUCIE RIVER RIVER DULHUNTY Kilometers Legend ( Port of Skardon River Mining Lease Boundaries Watercourses Local Catchments Project Footprint Existing Disturbance Footprint Figure 12-2 Local Catchments Gulf Alumina Limited Date: 15/08/2015 Revision: R1 Author: malcolm.nunn Map Scale: 1:150,000 Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_SurfaceWater\FIG_12_02_Local_Catchments_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery (inset, main): sourced from Gulf Alumina. Imagery (main) ESRI (2015).

11 Wetlands A number of different wetland mapping systems exist for wetlands in Queensland. Potential wetlands within and surrounding the Project have been mapped by EHP, and are shown in: Figure 12-3 for EHP WetlandInfo mapping which separates wetlands into marine, estuarine, riverine, lacustrine and palustrine Figure 12-5 for EHP s map of referable wetlands showing high ecological significance wetlands and general high ecological significance wetlands (noting that there are no mapped wetland protection areas ) Figure 12-6 for EHP s Vegetation Management Act wetlands Figure 12-7 from the Directory of Important Wetlands in Australia (DIWA), nationally important wetlands as recognised by the Commonwealth (noting that these are not MNES) The wetland maps demonstrate that similar areas are considered to be wetlands but are given different status and recognition under various legislation and mapping systems. Downstream of the Project area, Namaleta Creek is shown as containing estuarine water bodies and estuarine regional ecosystems. Immediately downstream and upstream of the Project area, Namaleta Creek is shown as having palustrine waterbodies and palustrine regional ecosystems. There are two small areas of riverine waterbody and lacustrine waterbody on Namaleta Creek. The lacustrine waterbodies are the existing kaolin mine water storage pits. To the west and downstream of the Project area, there are palustrine waterbodies, palustrine regional ecosystems, riverine regional ecosystems and estuarine regional ecosystems. These include Bigfoot Swamp and Lunette Swamp. The Skardon River is mapped as an estuarine waterbody with estuarine regional ecosystems. There are high ecological significance (HES) wetlands mapped along the Skardon River (including the South Arm); Namaleta Creek downstream of the existing crossing; drainage line of Namaleta Creek in the south east of the Project area between Pit 14 and Pit 15; Bigfoot Swamp; and wetlands in the wetland complex to the west of the Project area. There are general ecological significance (GES) wetlands mapped along Namaleta Creek immediately downstream and upstream of the existing crossing; Lunette Swamp and some wetlands in the wetland complex to the west of the Project. Field surveys have confirmed an inconspicuous wetland zone between the mangroves and the base of the bauxite plateau along the Skardon River South Arm. This area is referred to as the supratidal wetlands to the west of the Skardon River South Arm and falls within the mapped HES wetland in this area. There are two DIWA wetlands - The Skardon River Cotterell River Aggregation which lies along the Skardon River and within the localised catchments downstream and west of the Project area; and the Port Musgrave Aggregation which covers the Port of Musgrave to the south of the Project and estuarine areas of Namaleta Creek. For the purpose of describing freshwater wetlands and assessing potential Project impacts, the following wetland groupings have been considered: Lunette Swamp Bigfoot Swamp Namaleta Creek (freshwater sections) The HES wetlands bisecting Pits 14 and 15 Supratidal wetlands to the west of the Skardon River South Arm Wetland complexes to the west and north of the Project area. Page 12-7

12 For the purpose of describing marine and estuarine wetlands and assessing potential Project impacts, the following wetland groupings have been considered: Skardon River estuarine areas Namaleta Creek estuarine areas The hydrology of wetlands and the hydrogeology of the Project area is described in Chapter 13. The wetlands within and surrounding the Project area include several groundwater dependent ecosystems located along drainage lines which comprise valley fill alluvial deposits with underlying shallow aquifer systems. All freshwater wetlands are likely to be recharged by surface water during the wet season and maintained during the dry season by seasonally perched groundwater recharge. All wetlands are considered to be shallow aquifer groundwater dependent ecosystems. Based on site knowledge, Lunette Swamp and Bigfoot Swamp wetlands dry out during the dry season, except for small ponds at the lower end of Bigfoot Swamp, which can also dry out in some years. Lunette Swamp dries out fairly rapidly, by July 2015 there was no water in Lunette Swamp. The palustrine wetlands across the Project area are associated with depressions and water course drainage lines. In addition to retaining water they are also a repository of soils and sediments that will retain nutrients to support local biodiversity. The detailed nature of partitioning of the various components of the hydrological cycle rainfall, runoff, recharge and baseflow, as they affect wetlands, is understood at a conceptual level for the area. These wetlands are dependent on surface water and groundwater interaction. The riverine and estuarine wetlands reaches of Namaleta Creek adjacent to the Project and further downstream are affected by the behaviour of runoff and baseflows entering the Creek. Field ecological surveys have resulted in the delineation of vegetation communities or map units, which have been used to derive field mapped regional ecosystems (REs)(Refer Chapter 15), including vegetation map units / REs associated with wetlands. In general field mapped vegetation map units associated with wetlands correspond to government mapped wetlands. However the following areas of government mapped wetland are not likely to be wetland habitat: Some areas along the north side of Namaleta Creek (RE / vegetation map unit 2 -tall grassy woodland of Corymbia novoguinensis over Livistona muelleri with Eucalyptus brassiana to 28 m on humic soil) The mapped HES wetland between Pit 14 and 15 (RE a / vegetation map unit 9), which is likely to contain RE a (woodland of Corymbia novoguinensis over Livistona muelleri, occasionally with Eucalyptus tetrodonta), classified as floodplain (other than floodplain wetlands ) by EHP. Further information on the wetland vegetation communities is provided in Chapter 15 and Chapter 16. The identified wetlands are not matters of national environmental significance (MNES). Listed species which are associated with wetlands are described in Chapter 16. The Ramsar Convention (The Convention on Wetlands of International Importance) is an international treaty for the conservation and sustainable utilisation of wetlands. Australia is a signatory to this convention. The Ramsar List of Wetlands of International Importance now includes 1,950 sites (known as Ramsar Sites). A desktop search of Ramsar Wetlands did not identified any Ramsar wetlands within or adjacent to the Project area. Page 12-8

13 ± CAIRNS Queensland TOWNSVILLE ROCKHAMPTON BRISBANE SKARDON RIVER ML ML ( Bigfoot Swamp NAMALETA CREEK Lunette Swamp ML 6025 Pit #14 CREEK NAMALETA Pit # Pit #15 Pit #15 1:20, Kilometers Legend ( Port of Skardon River Mining Lease Boundaries Existing Disturbance Footprint Project Footprint Southern Haul Road Watercourses Water Bodies Marine Estuarine Riverine Lacustrine Palustrine Wetland Regional Ecosystem Estuarine Riverine Palustrine Figure 12-3 Date: 8/10/2015 Revision: R1 Wetlands - Queensland WetlandInfo Mapping Author: malcolm.nunn Map Scale: 1:80,000 Gulf Alumina Limited Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_03_WetlandInfo_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery sourced from Gulf Alumina. Queensland Wetland Data Version 3.0 State of Queensland - Department of Science, Information Technology, Innovation and the Arts (2013).

14 NAMALETA CREEK ± CAIRNS TOWNSVILLE Queensland ROCKHAMPTON BRISBANE Pit #14 Pit # ,000 1,500 2,000 Meters Legend ( Port of Skardon River Mining Lease Boundaries Existing Disturbance Footprint Project Footprint Southern Haul Road Watercourses Water Bodies Estuarine Riverine Lacustrine Palustrine Wetland Regional Ecosystem Estuarine Palustrine Wetlands of Namaleta Creek Catchment - Queensland WetlandInfo Mapping Figure 12-4 Date: 8/10/2015 Revision: R1 Author: malcolm.nunn Map Scale: 1:17,500 Gulf Alumina Limited Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_04_WetlandInfo_Namaleta_Zoom_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery sourced from Gulf Alumina. Queensland Wetland Data Version 3.0 State of Queensland - Department of Science, Information Technology, Innovation and the Arts (2013).

15 ± SKARDON RIVER CAIRNS TOWNSVILLE Queensland ROCKHAMPTON BRISBANE ML ML ( Bigfoot Swamp NAMALETA CREEK Lunette Swamp ML 6025 Pit #14 NAMALETA CREEK Pit # Pit # Pit #15 NAMALETA CREEK 1:20, Kilometers Legend ( Port of Skardon River Mining Lease Boundaries Existing Disturbance Footprint Project Footprint Southern Haul Road Watercourses Wetland Management Area HES Wetland GES Wetland Figure 12-5 Date: 8/10/2015 Revision: R1 Referrable Wetlands - Wetland Management Areas Author: malcolm.nunn Map Scale: 1:80,000 Gulf Alumina Limited Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_05_Referrable_Wetlands_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery sourced from Gulf Alumina. Wetland Management Areas State of Queensland (Department of Environment and Heritage Protection) Wetland Buffer provided by RPS.

16 ± SKARDON RIVER CAIRNS TOWNSVILLE Queensland ROCKHAMPTON BRISBANE ML ML ( Bigfoot Swamp NAMALETA CREEK Lunette Swamp ML 6025 Pit #14 NAMALETA CREEK Pit # Pit # Pit #15 NAMALETA CREEK 1:20, Kilometers Legend ( Port of Skardon River Mining Lease Boundaries Existing Disturbance Footprint Project Footprint Southern Haul Road VMA Watercourses VMA Wetlands Vegetation Management Act Wetlands and Watercourses Figure 12-6 Date: 8/10/2015 Author: malcolm.nunn Map Scale: 1:80,000 Gulf Alumina Limited Revision: R1 Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_06_VMA_Wetlands_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery sourced from Gulf Alumina. VM Wetlands & Watercourses State of Queensland (DNRM 2015). Wetland Buffer provided by RPS.

17 ± CAIRNS TOWNSVILLE Queensland ROCKHAMPTON BRISBANE ML ML ( NAMALETA CREEK ML 6025 Pit #14 NAMALETA CREEK Pit # Pit # Pit #15 NAMALETA CREEK 1:20, Kilometers Legend ( Port of Skardon River Mining Lease Boundaries Existing Disturbance Footprint Project Footprint Southern Haul Road Watercourses Directory of Important Wetlands Directory of Important Wetlands Figure 12-7 Gulf Alumina Limited Date: 8/10/2015 Author: malcolm.nunn Map Scale: 1:80,000 Revision: R1 Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_07_Directory_Important_Wetlands_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery sourced from Gulf Alumina. Directory of Important Wetlands State of Queensland - Department of Environment and Heritage Protection (2014). Wetland Buffer provided by RPS.

18 12.5 Water Quality Objectives Environmental Values from EPP Water These waters of the Project area are considered to be high ecological value (waters in which the biological integrity of the water is effectively unmodified or highly valued). The former kaolin mining operations in the Project area, are not considered to have modified physical, chemical or other indicators. The following EVs listed under the EPP Water are considered relevant to the waters potentially impacted by the Project: For high ecological value waters - the biological integrity of an aquatic ecosystem. For waters that may be used for recreation or aesthetic purposes - the suitability of the water for secondary recreational use or visual recreational use. Secondary use involves boating and fishing. There are low levels of recreational fishing, and associated camping (not in the Project s mining leases), in the Skardon River. For waters that may be used for producing aquatic foods for human consumption - the suitability of the water for producing the foods for human consumption. There is very limited use of the waters for commercial fishing and no production of aquatic foods in the identified waters. For waters that may be used for drinking water - the suitability of the water for supply as drinking water. Only one shallow groundwater bore in the Project area is used for drinking water (kaolin mine camp supply only) and will be the supply source for the Project s camp. There are no known human drinking water users of other fresh surface water sources from the identified waters. For waters that may be used for industrial purposes - the suitability of the water for industrial use. Shallow groundwater will be used for the Project s mining operations (e.g. dust suppression). In addition, surface water and / or groundwater may be used by other nearby proposed mining operations in the future. The water quality is considered suitable for this purpose. The cultural and spiritual values of the water. Indigenous people and groups with links to the Project area have cultural and spiritual connections to the water. In addition to fishing, members of the Indigenous community use the area for hunting. Namaleta Creek, Skardon River Estuary, Bigfoot Swamp and Lunette Swamp are all of cultural and spiritual value to the Traditional Owners. The following EVs listed under the EPP Water are not considered relevant to the waters potentially impacted by the Project: For waters that may be used for recreation or aesthetic purposes, the suitability of the water for primary recreational use. Primary recreational use involves full body contact with the water which, due to the presence of crocodiles and sharks, is highly unlikely to occur. For waters that may be used for aquaculture - the suitability of the water for aquacultural use. There is no known existing or proposed aquacultural uses of the identified waters. For waters that may be used for agricultural purposes - the suitability of the water for agricultural purposes. There are no known existing uses of the identified waters for agricultural purposes. This does not preclude the use of these waters at some point in future for agricultural purposes Water Quality Objectives As described in Section , the QWQG recommends the use of local water quality objectives developed for appropriate indicators / parameters using monitoring data from local reference sites. Page 12-14

19 There is insufficient sampling data for some parameters with which to establish local water quality objectives under the QWQG. The QWQG does not provide guideline values for the region in which the Project is located. In addition, there are no site / waterway specific documents under the EPP Water for the identified waters. Therefore water quality objectives for the identified waters are based on the AWQG, where there is insufficient local water quality data. The identified waters occur in tropical Australia at altitudes below 50m. The most appropriate AWQG trigger values to use are: the physico-chemical trigger values for lowland rivers in tropical Australia for slightly disturbed ecosystems (noting that there are no physico-chemical trigger values for high ecological value waters) the physico-chemical trigger values for wetlands in tropical Australia for slightly disturbed ecosystems (noting that there are no physico-chemical trigger values for high ecological value waters) the toxicant trigger values for metal and metalloids to achieve 99% aquatic ecosystem protection (applicable to high ecological value ecosystems) the toxicant trigger values for heavy metals and metalloids in livestock drinking water (noting that there is no current pastoral activity involving the identified waters). The AWQG trigger values, are provided in Table 12-1 and have also been compared to the release limits and trigger investigation levels provided in the Model Mining Conditions (EHP, 2014) and the receiving waters contaminant trigger levels of the existing environmental authority (kaolin mining). The AWQG does not provide trigger values for certain parameters, as noted in Table Surface water and groundwater quality data, presented in Section 12.6 and Section 12.7 respectively, has been analysed for the 80 th percentile for comparison to the AWQG values and to provide local water quality objectives where there is sufficient data. The parameters for which there is sufficient data collected to meet the requirements of the QWQGs are: Namaleta Creek (refer Table 12-5) electrical conductivity (EC) 128 samples, collected over 19 months from 2008 to 2015 at sites S1, S2, S6, S8, S9 ph 124 samples, collected over 19 months from 2008 to 2015 at sites S1, S2, S6, S8, S9 total dissolved solids (TDS) 46 samples collected over 5 months from 2014 to 2015 at sites S1, S2, S6, S8, S9 turbidity 134 samples, collected over 19 months from 2008 to 2015 at sites S1, S2, S6, S8, S9 Other parameters, although not meeting the criteria for local water quality objectives provide a reasonable indication of likely local water quality objectives that will be derived following additional monitoring. Note that one set of draft water quality objectives for all aquifers and surface water systems may not be appropriate. For the purpose of nominating water quality objectives for the Project s environmental management plan (EM Plan) (Appendix 13), separate water quality objectives have been proposed for: Namaleta Creek wetlands groundwater Page 12-15

20 Although groundwater data demonstrates variances between water quality at different shallow aquifers in the Project area, further monitoring data is required to inform the Project s EM Plan and therefore one set of water quality objectives is proposed for all groundwater. The methodology used for selection of the nominated water quality objectives for the Project is: 1. where there is sufficient data to set local water quality objectives, the 80 th percentiles from sampling data has been used, and 2. where there is insufficient data to set local water quality objectives the lowest value from either the AWQG or Model Mining Conditions has been selected. The nominated water quality objectives for the Project are presented in Table Page 12-16

21 Page Table 12-1 Water Quality Trigger Values AWQG, Model Mining Conditions, Existing EA and Site Monitoring Data Parameter Unit AWQG Trigger Value Tropical Lowland Rivers AWQG Trigger Value Tropical Wetlands AWQG Trigger Value 99% Protection AWQG Trigger Value Livestock (cattle) Model Mining Conditions Existing EA Surface water Existing EA ground water Ground Water Monitoring Data (80th percentile) Salinity, electrical conductivity (EC) µs/cm n/a n/a Site specific - as per described method Higher of 900 or the 80th percentile of the reference site Higher of 900 or the 80th percentile of the reference bore, max 500 Namaleta Creek Monitoring Data (80th percentile) Wetland Monitoring Data (80th percentile) TDS = total dissolved solids mg/l n/a n/a n/a n/a n/a n/a Turbidity NTU n/a n/a n/a Higher of 20 or the 80th percentile of the reference site n/a ISD TSS = total suspended solids µg/l n/a n/a n/a n/a n/a n/a n/a ISD ISD ISD ph ph units n/a n/a Lowest of 7 or the 20th percentile of the reference site to higher of 8.5 or the 80th percentile of the reference site As per surface water 20 th %ile = th %ile = 5.83 Min = 4.8 Max = th %ile = th %ile = 5.45 Min = 4.08 Max = th %ile = th %ile = 6.02 Min = 5.6 Max = 6.2 Chl a = chlorophyll a µg/l 5 10 n/a n/a n/a n/a n/a ISD ISD ISD

22 Page Parameter Unit AWQG Trigger Value Tropical Lowland Rivers TP = total phosphorus FRP = filterable reactive phosphate TN = total nitrogen NOx = oxides of nitrogen NH4+ = ammonium DO = dissolved oxygen Chemical oxygen demand Nitrate Nitrogen, NO3 as N AWQG Trigger Value Tropical Wetlands AWQG Trigger Value 99% Protection AWQG Trigger Value Livestock (cattle) Model Mining Conditions Existing EA Surface water Existing EA ground water Ground Water Monitoring Data (80th percentile) Namaleta Creek Monitoring Data (80th percentile) Wetland Monitoring Data (80th percentile) µg/l n/a n/a n/a n/a n/a 110 ISD 178 µg/l n/a n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a n/a n/a n/a µg/l n/a n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a 900 n/a Higher of 15 or the 80th percentile of the reference bore, max 500 % saturation ISD ISD ISD n/a n/a n/a n/a n/a ISD ISD ISD mg/l n/a n/a n/a n/a n/a n/a Higher of 40 or the 80th percentile of the reference bore ISD ISD ISD µg/l n/a n/a n/a n/a 1100 n/a n/a ISD ISD ISD

23 Page Parameter Unit AWQG Trigger Value Tropical Lowland Rivers Nitrite Nitrogen, NO2 as N Organic Nitrogen (calc) Total Kjeldahl Nitrogen Aluminium (total and dissolved) Arsenic (III) (total and dissolved) Arsenic (V) (total and dissolved) Boron (total and dissolved) Cadmium (total and dissolved) Chromium (VI) (total and dissolved) Cobalt (total and dissolved) AWQG Trigger Value Tropical Wetlands AWQG Trigger Value 99% Protection AWQG Trigger Value Livestock (cattle) Model Mining Conditions Existing EA Surface water Existing EA ground water Ground Water Monitoring Data (80th percentile) Namaleta Creek Monitoring Data (80th percentile) Wetland Monitoring Data (80th percentile) µg/l n/a n/a n/a n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a n/a n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a n/a n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a n/a n/a µg/l n/a n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a 0.8 n/a 13 n/a n/a 1.4 ISD ISD µg/l n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a n/a n/a 1.6 ISD ISD µg/l n/a n/a ID n/a n/a ISD ISD ISD

24 Page Parameter Unit AWQG Trigger Value Tropical Lowland Rivers Copper (total and dissolved) AWQG Trigger Value Tropical Wetlands AWQG Trigger Value 99% Protection AWQG Trigger Value Livestock (cattle) Model Mining Conditions Existing EA Surface water Existing EA ground water Ground Water Monitoring Data (80th percentile) Namaleta Creek Monitoring Data (80th percentile) Wetland Monitoring Data (80th percentile) µg/l n/a n/a n/a n/a Fluoride µg/l n/a n/a n/a n/a n/a ISD ISD ISD Iron (total and dissolved) Lead (total and dissolved) Manganese (total and dissolved) Mercury (total and dissolved) Molybdenum (total and dissolved) Nickel (total and dissolved) Selenium (total and dissolved) Silver (total and dissolved) Uranium(total and dissolved) µg/l n/a n/a ID NST 300 n/a n/a µg/l n/a n/a n/a n/a 1.2 ISD ISD µg/l n/a n/a 1200 NST 1900 n/a n/a µg/l n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a ID n/a n/a ISD ISD ISD µg/l n/a n/a n/a n/a 7 ISD ISD µg/l n/a n/a n/a n/a ISD ISD ISD µg/l n/a n/a 0.02 ND 1 n/a n/a ISD ISD ISD µg/l n/a n/a ID n/a n/a ISD ISD ISD

25 Page Parameter Unit AWQG Trigger Value Tropical Lowland Rivers Vanadium (total and dissolved) AWQG Trigger Value Tropical Wetlands AWQG Trigger Value 99% Protection AWQG Trigger Value Livestock (cattle) Model Mining Conditions Existing EA Surface water Existing EA ground water Ground Water Monitoring Data (80th percentile) Namaleta Creek Monitoring Data (80th percentile) Wetland Monitoring Data (80th percentile) µg/l n/a n/a ID ND 10 n/a n/a ISD ISD ISD Zinc (total and dissolved) Petroleum hydrocarbons (C6-C9) Petroleum hydrocarbons (C10-C36) µg/l n/a n/a n/a n/a 90.8 ISD ISD µg/l n/a n/a ID n/a 20 n/a No visible film or detectable odour µg/l n/a n/a ID n/a 100 n/a No visible film or detectable odour ISD ISD ISD ISD ISD ISD n/a = not applicable or not provided ID = Insufficient data as per AWQG ISD = Insufficient sampling data to set draft trigger values 80th percentile ND = Not determined as per AWQG NST = not sufficiently toxic as per AWQG Site specific trigger values based on dissolved metal species

26 Table 12-2 Nominated Water Quality Objectives Parameter Unit Namaleta Creek Water Quality Objectives Salinity, electrical conductivity (EC) TDS = total dissolved solids Basis for Nomination µs/cm 50 site sampling data Wetland Water Quality Objectives Basis for Nomination 90 AWQG - tropical wetlands Groundwater Quality Objectives Basis for Nomination 90 AWQG - tropical wetlands mg/l n/a n/a n/a n/a n/a n/a Turbidity NTU 4.5 site sampling data TSS = total suspended solids 4.5 site sampling data within the range of AWQG - tropical wetlands µg/l n/a n/a n/a n/a n/a n/a ph ph units site sampling data (min to max) Chl a = chlorophyll a TP = total phosphorus FRP = filterable reactive phosphate TN = total nitrogen NOx = oxides of nitrogen NH4+ = ammonium µg/l 5 AWQG - tropical rivers µg/l 10 AWQG - tropical rivers µg/l 4 AWQG - tropical rivers µg/l 200 AWQG - tropical rivers µg/l 10 AWQG - tropical rivers µg/l 10 AWQG - tropical rivers AWQG - tropical wetlands, recognising low ph of sampling data 10 AWQG - tropical wetlands 10 AWQG - tropical wetlands 5 AWQG - tropical wetlands 350 AWQG - tropical wetlands 10 AWQG - tropical wetlands 10 AWQG - tropical wetlands n/a n/a AWQG - tropical waters, recognising low ph of sampling data 5 AWQG - tropical rivers 10 AWQG - tropical rivers 4 AWQG - tropical rivers 200 AWQG - tropical rivers 10 AWQG - tropical rivers 10 AWQG - tropical rivers Page 12-22

27 Parameter Unit Namaleta Creek Water Quality Objectives DO = dissolved oxygen Chemical oxygen demand Nitrate Nitrogen, NO3 as N Nitrite Nitrogen, NO2 as N Organic Nitrogen (calc) Total Kjeldahl Nitrogen Aluminium (total and dissolved) Arsenic (III) (total and dissolved) Arsenic (V) (total and dissolved) Boron (total and dissolved) Cadmium (total and dissolved) Chromium (VI) (total and dissolved) Cobalt (total and dissolved) Copper (total and dissolved) % saturation Basis for Nomination AWQG - tropical rivers Wetland Water Quality Objectives Basis for Nomination AWQG - tropical wetlands Groundwater Quality Objectives Basis for Nomination AWQG - tropical rivers mg/l n/a n/a n/a n/a n/a n/a µg/l 1100 Model Mining Conditions 1100 Model Mining Conditions 1100 Model Mining Conditions µg/l n/a n/a n/a n/a n/a n/a µg/l n/a n/a n/a n/a n/a n/a µg/l n/a n/a n/a n/a n/a n/a µg/l 27 AWQG - 99% 27 AWQG - 99% µg/l 1 AWQG - 99% 1 AWQG - 99% µg/l 0.8 AWQG - 99% 0.8 AWQG - 99% µg/l 90 AWQG - 99% 90 AWQG - 99% µg/l 0.06 AWQG - 99% 0.06 AWQG - 99% µg/l 0.01 AWQG - 99% 0.01 AWQG - 99% µg/l 90 Model Mining Conditions 90 Model Mining Conditions µg/l 1 AWQG - 99% 1 AWQG - 99% Fluoride µg/l 2000 AWQG - 99% 2000 AWQG - 99% 27 AWQG - 99% 1 AWQG - 99% 0.8 AWQG - 99% 90 AWQG - 99% 0.06 AWQG - 99% 0.01 AWQG - 99% 90 Model Mining Conditions 1 AWQG - 99% 2000 AWQG - 99% Page 12-23

28 Parameter Unit Namaleta Creek Water Quality Objectives Iron (total and dissolved) Lead (total and dissolved) Manganese (total and dissolved) Mercury (total and dissolved) Molybdenum (total and dissolved) Nickel (total and dissolved) Selenium (total and dissolved) Silver (total and dissolved) Uranium(total and dissolved) Vanadium (total and dissolved) Zinc (total and dissolved) Petroleum hydrocarbons (C6-C9) Petroleum hydrocarbons (C10-C36) Basis for Nomination µg/l 300 Model Mining Conditions Wetland Water Quality Objectives Basis for Nomination 300 Model Mining Conditions µg/l 1 AWQG - 99% 1 AWQG - 99% µg/l 1200 AWQG - 99% 1200 AWQG - 99% µg/l 0.06 AWQG - 99% 0.06 AWQG - 99% µg/l 34 Model Mining Conditions 34 Model Mining Conditions µg/l 8 AWQG - 99% 8 AWQG - 99% µg/l 5 AWQG - 99% 5 AWQG - 99% µg/l 0.02 AWQG - 99% 0.02 AWQG - 99% µg/l 1 Model Mining Conditions µg/l 10 Model Mining Conditions 1 Model Mining Conditions 10 Model Mining Conditions µg/l 2.4 AWQG - 99% 2.4 AWQG - 99% µg/l 20 Model Mining Conditions µg/l 100 Model Mining Conditions 20 Model Mining Conditions 100 Model Mining Conditions Groundwater Quality Objectives Basis for Nomination 300 Model Mining Conditions 1 AWQG - 99% 1200 AWQG - 99% 0.06 AWQG - 99% 34 Model Mining Conditions 8 AWQG - 99% 5 AWQG - 99% 0.02 AWQG - 99% 1 Model Mining Conditions 10 Model Mining Conditions 2.4 AWQG - 99% 20 Model Mining Conditions 100 Model Mining Conditions Page 12-24

29 12.6 Surface Water Monitoring Surface Water Monitoring Locations Surface water monitoring has occurred intermittently in the Project area over the past 25 years, primarily to identify potential impacts of the former kaolin mine operations. Surface water monitoring has occurred at the locations listed in Table 12-3 and shown in Figure Surface water monitoring sites have been assigned different names over the course of kaolin mining activities. These historical names are provided in Table 12-3, including noting monitoring site names under the current environmental authority. Surface water level monitoring was undertaken from mid 2014 at S10 and S11, and from early 2015 at S1, S8 and S9. Monitoring of physical parameters (ph and EC) has been undertaken at most sites since early 2008, with more comprehensive monitoring including selected metals and nutrients since February During 2015, surface water monitoring comprised 10 locations across the Project area. Water quality parameters measured in the field include ph, EC, TDS, turbidity, DO and redox. In addition there were laboratory determinations of selected metals. Laboratory analysis was undertaken by a NATA accredited laboratory. There was limited testing for nutrients, which is of limited value as baseline data, but has been included for completeness. Note that sites S3, S4 and S5 are located within the existing kaolin mine water storage pits and hence water quality at these sites is not representative of ambient / baseline water quality in natural systems, and is therefore presented separately below. Site S13 monitors water quality from releases from the existing Port sediment pond, which are extremely limited to date and do not provide representative baseline water quality, and hence data is not provided for this site. Marine water quality data is presented in Chapter 17. Site S7 has limited marine water quality from the estuarine section of Namaleta Creek. Site S14 has had limited sampling from the marine / estuarine environment at the Port, but will potentially be a monitoring site for an alternative Port sediment pond proposed for the Project. Data for site S7 and S14 is not presented. Sites S7, S15, S16 and S17 are proposed for ongoing marine / estuarine water quality sampling. Site S18 is proposed for monitoring of the supratidal wetland along the Skardon River South Arm. Table 12-3 Site Number Surface Water Monitoring Data Historical Site Name Easting Northing Creek / Water Body Water Level Data S1 Nam Namaleta Creek upstream of all proposed mining S2 Upstream Water Pit (per EA) S3 W1 (per EA) discharge point from raw water pit Namaleta Creek upstream of kaolin mine, downstream of some bauxite mining from January 2015 n/a Water Quality Data from February 2015 from January Raw Water Pit n/a from January 2008 S4 n/a Raw Water Pit n/a from January 2008 Page 12-25

30 Site Number Historical Site Name S5 W6 (per EA) discharge point from western sump of fluvial Pit S6 Namaleta Downstream (per EA) Easting Northing Creek / Water Body Water Level Data Water Quality Data Fluvial Pit n/a from January Namaleta Creek, downstream of kaolin and bauxite mining S7 n/a Namaleta Creek (estuarine), downstream of kaolin and bauxite mining S8 Nam Namaleta Creek, downstream of existing S9 Namaleta Crossing Down, Nam-2 Creek crossing Namaleta Creek, upstream of existing Creek crossing n/a n/a from January 2015 from January 2015 S10 Lunette Lunette Swamp from July 2014 S11 Bigfoot Bigfoot Swamp from July 2014 from January 2008 From July 2015 n/a from January 2008 from February 2015 from March 2015 from June 2015 S12 n/a Lunette Swamp, downstream n/a S14 n/a Skardon River (estuarine) n/a from June 2015 Page 12-26

31 Queensland CAIRNS TOWNSVILLE ± ROCKHAMPTON BRISBANE S17 S14 ( SKARDON RIVER ML ( S13 (W2 (EA)) 1:30,000 ML S16 S18 S11 (Bigfoot 1 / Northern Hole / S2) NAMALETA CREEK S6 S5 (W6 (EA) / Pit-2 / S7) S3 (W1 (EA)) S S9 (Nam-2 / S4) S8 (Nam-3 / S5) S4 (Pit-1 / S6) S2 (Upstream Water Pit (EA)) S1 (Nam-1 / S3) S12 ML 6025 S10 (Lunette 1 / S1) S7 NAMALETA CREEK :30, Kilometers Legend Mining Lease Boundaries ( Port of Skardon River Watercourses Surface Water Monitoring Locations Depth logger Marine water quality Water quality Water quality and depth logger Figure 12-8 Date: 23/09/2015 Revision: R1 Surface Water Monitoring Locations Author: malcolm.nunn Map Scale: 1:80,000 Gulf Alumina Limited Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_08_SWMP_Locations_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery ESRI (2015).

32 Surface Water Level Data Results of surface water level logging are provided in Table 12-4, and illustrated in graphs in Appendix 4, with an example for site S8 presented in Figure These graphs also show rainfall during the monitoring period. There are some data spikes and drop outs noted in the data, these are likely due to the retrieval of the logger for downloading of data. These irregularities have been filtered from the data for the purpose of interpretation in this report. The surface water level records have not been reduced to any local survey datum. Hence, surface water data records refer to water surface depths above the logger level. Despite this, the data is useful in understanding the seasonal variation in water levels and the response to rainfall events. Surface water level in all locations is seasonally variable, with elevated water levels in the period February to March each year, co-incident with the wet season. The variation in water level between wet and dry seasons is between 0.88 to 4.2m, depending on the location. It is noted that water level responds very directly to rainfall, with an almost immediate response in water level to rainfall events apparent in Namaleta Creek. The response to rainfall of the sites in Lunette Swamp and Bigfoot Swamp is more subdued. Table 12-4 Surface Water Levels Site Number Location Minimum Water Level (m) Maximum Water Level (m) Seasonal Water Level Range (m) S1 Namaleta Creek S8 Namaleta Creek S9 Namaleta Creek S10 Lunette Swamp S11 Bigfoot Swamp Figure 12-9 Site S8 Surface Water Level and Rainfall Page 12-28

33 Surface Water Quality Skardon River Bauxite Project The results of surface water quality testing are tabulated and graphed in Appendix 4. The physical parameters from surface water monitoring has been summarised by the location, either Namaleta Creek, the wetlands (Lunette Swamp and Bigfoot Swamp) or kaolin water storages (Raw Water Pit and Fluvial Pit). Physical parameter data from surface water has been obtained from Namaleta Creek over four wet seasons, and thus there is enough data to propose statistically valid site specific trigger values in accordance with the AWQG for a limited number of parameters (EC, ph TDS and turbidity). The bulk of the trace metal and nutrient surface water quality data for Namaleta Creek has been obtained during a four month period of Thus, there is not enough data to propose statistically valid site specific trigger values for metals and nutrients in accordance with the AWQG. Despite this, there is sufficient data to make some initial interpretation of the surface water quality onsite Physical Parameters Physical parameters for Namaleta Creek, the wetlands and kaolin water storages are presented in Table 12-5 Table 12-6 and Table 12-7 respectively. Note that there was not enough data for dissolved oxygen and redox for valid statistics. The 20 th percentile was only calculated for ph. ph is moderately acidic to neutral, ranging from 4.08 to 7.13 ph units. The weakly acidic ph is a reflection of the geology of the catchment. EC is low, ranging from 16 to 440 µs/cm. The majority of EC is very low, with the 80th percentile value of 50 µs/cm for Namaleta Creek, 32 µs/cm for the wetlands and 97 µs/cm for the kaolin water stoarges. It is noted that elevated values can be recorded at site S6 (including the maximum of 440 µs/cm) and this is interpreted to occur due to high tidal levels, coincident with the dry season (hence low water levels in Namaleta Creek). Table 12-5 Surface Water Physical Parameter Summary Results Namaleta Creek Sites Statistical Element ph (ph units) EC (µs/cm) TDS Turbidity (NTU) S1,S2, S6, S8, S9 minimum maximum mean median th percentile th percentile n Table 12-6 Surface Water Physical Parameter Summary Results Wetlands Sites Statistical Element ph (ph units) EC (µs/cm) TDS Turbidity (NTU) S10, S11, S12 minimum maximum mean median th percentile th percentile n Table 12-7 Surface Water Physical Parameter Summary Results Kaolin Water Storages Sites Statistical Element ph (ph units) EC (µs/cm) TDS Turbidity (NTU) S3, S4, S5 minimum maximum Page 12-29

34 Sites Statistical Element ph (ph units) EC (µs/cm) TDS Turbidity (NTU) mean median th percentile th percentile n Metals Monitoring data for selected metals has been obtained, and is summarised in Table 12-8, Table 12-9 and Table for Namaleta Creek, the wetlands and the kaolin water storages respectively. Dissolved metals values are very low across almost all sites, when compared with the AWQG. Most samples results are below the detection limit. Two exception are: dissolved aluminium, which is variable and has a maximum of 0.1 mg/l in Namaleta Creek, 0.2 mg/l in the wetlands and 0.08 mg/l in the kaolin water storages (compared to mg/l per the AWQG) dissolved copper, which is variable and has a maximum of mg/l in Namaleta Creek, mg/l in the wetlands and mg/l in the kaolin water storages (compared to mg/l per the AWQG). It is considered that these values of metals reflect the geology of the site. Table 12-8 Surface Water Dissolved Metals Summary Results Namaleta Creek Sites Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn S1,S2, minimum n/a n/a n/a n/a n/a n/a n/a S6, maximum 0.1 n/a n/a n/a n/a n/a n/a n/a S8, S9 mean n/a n/a n/a n/a n/a n/a n/a median n/a n/a n/a n/a n/a n/a n/a 80th n/a n/a n/a n/a n/a n/a n/a percentile n n/a - Results all below the detection limit, or not enough results for valid statistics. Table 12-9 Surface Water Dissolved Metals Summary Results Wetlands Bores Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn S10, minimum n/a n/a n/a n/a n/a n/a n/a S11, maximum n/a n/a n/a n/a n/a n/a S12 mean n/a n/a n/a n/a n/a n/a n/a median n/a n/a n/a n/a n/a n/a n/a 80th 0.13 n/a n/a n/a n/a n/a n/a n/a percentile n n/a - Results all below the detection limit, or not enough results for valid statistics. Bores S3, S4, S5 Table Surface Water Dissolved Metals Summary Results Kaolin Water Storages Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn minimum n/a n/a n/a n/a n/a n/a maximum n/a n/a n/a n/a n/a n/a mean n/a n/a n/a n/a n/a n/a median n/a n/a n/a n/a n/a n/a Page 12-30

35 Bores Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn 80th n/a n/a n/a n/a n/a n/a percentile n n/a - Results all below the detection limit, or not enough results for valid statistics Nutrients Monitoring data for total nitrogen (TN) and total phosphorus (TP) has been obtained, and is summarised in Table 12-11, Table and Table for Namaleta Creek, the wetlands and the kaolin water storages respectively. Nutrient values (TN, TP) are low across all sites. It is generally noted that nutrients within the wetlands are an order of magnitude higher than levels recorded in Namaleta Creek. These elevated nutrient levels will be taken into account during longer term monitoring and management of site activities. Table Surface Water Nutrient Summary Results Namaleta Creek Sites Statistical Element Nitrogen (total) (mg/l N) Phosphorus (total) (mg/l P) S1,S2, S6, S8, S9 minimum 0.05 n/a maximum 0.16 n/a mean n/a median n/a 80th percentile 0.15 n/a n Table Surface Water Nutrient Summary Results - Wetlands Bores Statistical Element Nitrogen (total) (mg/l N) Phosphorus (total) (mg/l P) S10, S11, S12 minimum maximum mean median th percentile n Table Surface Water Nutrient Summary Results - Kaolin Water Storages Bores Statistical Element Nitrogen (total) (mg/l N) Phosphorus (total) (mg/l P) S3, S4, S5 minimum 0.05 n/a maximum 0.26 n/a mean n/a median 0.12 n/a 80th percentile n/a n Groundwater Monitoring Groundwater Monitoring Locations and Parameters Groundwater monitoring has occurred intermittently in the Project area over the past 25 years, primarily to support the former kaolin mine operations. However in the past 2 to 3 years groundwater monitoring (including groundwater level and quality) has also been undertaken to understand the reliability of water supply from shallow aquifers for the Project. In addition, groundwater quality Page 12-31

36 monitoring was undertaken in April 2015, June 2015 and July 2015 to provide additional data to support this EIS. In order to avoid creating turbidity in clear water and thereby provide more consistent and accurate sampling of more representative samples, the sampling methodology for groundwater was undertaken using the low-flow sampling and purging guidelines described in QED Environmental Systems Inc: Low- Flow Ground-Water Sampling: Latest Research and Equipment Options (2014). High purge volume sampling in low yield bores (such as those encountered within the Project area), can cause: an underestimation of maximum contaminant concentrations (due to dilution), an overestimation of contaminant concentrations due to contaminant mobilization and increased sample turbidity (e.g. turbidity can elevate metals and some organics bound to solids (e.g. polyaromatic hydrocarbons), losses of volatile organic compounds, affected DO and carbon dioxide levels, and increased sample turbidity. Groundwater monitoring has occurred at the locations listed in Table and shown in Figure Over the history of the mining leases dating back to the 1990 s groundwater bores have been given alternative naming conventions. The alternative naming conventions are shown in Table During 2015, groundwater monitoring within and surrounding the Project area comprised 14 bores located on Gulf Alumina s mining tenements (including exploration tenements adjoining the Project area) and 3 bores on Metro Mining s adjoining tenements. Monitoring of these bores includes continual measurement with logging equipment of the standing water levels (and in some cases of physical parameters), and water quality sampling on a monthly basis (from April 2015). Table summarises the details of the groundwater bores monitored on site. Water quality parameters measured in the field included ph, EC, TDS, DO and redox. In addition there were laboratory determinations of ph, EC, TDS, and selected metals. There was limited testing for nutrients, ions and hydrocarbons, which is of limited value as baseline data, but has been included for completeness. Note that the C1, C2 and C3 bores are nested, with a shallow bore screened in the Bulimba Formation and a deep bore screened in the Rolling Downs Siltstone in each case. The depth logger is installed in the deep bore, while water quality samples have been taken from both the shallow and deep bores. The hydrogeology of the Project area, including a description of the aquifers, is provided in Chapter 13, Section The aquifers for which monitoring data was obtained are, in order of depth from oldest to youngest, the Rolling Downs Formation, Bulimba Formation and alluvium, valley cut and fill deposits. The Namaleta aquifer is considered to be a meandering palaeochannel within these valley systems and is described as Bulimba Formation (Namaleta Creek) aquifer when discussing monitoring data below. For the purpose of this study, the aquifer monitored by the individual bores has been noted. Page 12-32

37 Page Table Groundwater Monitoring Data Bore Number Alternative Bore Name G1 Camp bore, Gulf 1, AKP01 G2 Gulf 3, EMB01 G3 Gulf 4, AKM10 G4 Gulf 6, AKM19s G5 Gulf 5, AKM26, G10 (per EA) Easting (m) Northing (m) Ground Level (m, AHD) Casing Height (m) Total Depth (m) Bulimba Formation Aquifer Screened Water Level Data Bulimba Formation Bulimba Formation (adjacent Bulimba Formation (adjacent Bulimba Formation G6 GMB Bulimba Formation G7 GMB Bulimba Formation G8 GMB Bulimba Formation G9 GMB Bulimba Formation G10 GMB Bulimba Formation from Nov 2013 from Nov 2013 from Nov 2013 from Nov 2013 from Nov 2013 from August 2014 from August 2014 from August 2014 from August 2014 from August 2014 Water Quality Data from February 2015 from April 2015 from April 2015 from April 2015 from April 2015 from April 2015 from April 2015 from April 2015 from April 2015 from April 2015

38 Page Bore Number Alternative Bore Name Easting (m) Northing (m) Ground Level (m, AHD) Casing Height (m) Total Depth (m) Aquifer Screened Water Level Data G11 GMB Bulimba Formation G12 AKM n/a Bulimba Formation (adjacent G13 AKM n/a Bulimba Formation (adjacent G14 AKM n/a Bulimba Formation (adjacent C1 Cape 1, Rolling Downs BH6 MB1 D Siltstone 101 C2 Cape 2, BH6 MB2 D 419 C3 Cape 3, BH6 MB3 D Rolling Downs Siltstone Rolling Downs Siltstone Water Quality Data n/a from April 2015 n/a from July 2015 n/a from July 2015 n/a from July 2015 from March 2014 from March 2014 from March 2014 from March 2015 from March 2015 from March 2015

39 Queensland CAIRNS TOWNSVILLE ± ROCKHAMPTON BRISBANE ( SKARDON RIVER ML ( ML G5 (AKM26 / G10(EA)) 1:30, G13 (AKM08) G14 (AKM07) G2 (Gulf 3 G12 / EMB02) (AKM09) G3 (Gulf 4 / AKM10) C2 (Cape 2 / BH6 MB2 D 419) G10 (G-MB4) G11 (G-MB5) G9 (G-MB3) C3 (Cape 3 / BH6 MB3 D 230) G8 (G-MB1) C1 (Cape 1 / BH6 MB1 D 101) G7 (G-MB6) ML 6025 NAMALETA CREEK G6 (G-MB2) G1 (Gulf 1 / Gulf 2 / AKP01) G4 (AKM19s) NAMALETA CREEK :30, Kilometers Legend Mining Lease Boundaries ( Port of Skardon River Watercourses Groundwater Monitoring Locations Figure Date: 6/10/2015 Groundwater Monitoring Locations Author: malcolm.nunn Map Scale: 1:80,000 Gulf Alumina Limited Revision: R1 Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_10_GWMP_Locations_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery ESRI (2015).

40 Groundwater Levels Results of groundwater level logging are tabulated and graphed in Appendix 4. Groundwater levels are summarised in Table and graphs are presented for bore C1 in Figure and bore G3 in Figure These graphs are representative of trends in groundwater levels observed in all bores. The graphs show rainfall during the monitoring period. There are some data spikes and drop outs noted in the graphs, these are likely due to the retrieval of the logger for downloading of data. These irregularities have been filtered from the data for the purpose of groundwater interpretation in this report. Groundwater level in all aquifers is seasonally variable, with elevated groundwater levels in the period February to March each year, co-incident with the wet season. The variation in groundwater level between wet and dry seasons is between 3.9 to m, depending on the bore. Groundwater level responds very directly to recharge from rainfall, with an almost immediate response in groundwater level to rainfall events apparent in all bores in Bulimba Formation aquifers. The response to rainfall of the bores in the Rolling Downs Siltstone aquifer is more subdued. The decline in groundwater level in the bores located in proximity to Namaleta Creek (noted in Table as bores in the Bulimba Formation Namaleta Creek aquifer) is slower when compared with bores located distant to Namaleta Creek. It is thus interpreted that there is some recharge to this aquifer from flows within Namaleta Creek. Table Groundwater Level Data Bore Number Aquifer Minimum Water Level (m, AHD) Maximum Water Level (m, AHD) Seasonal Water Level Range (m) G1 Bulimba Formation G2 Bulimba Formation G3 Bulimba Formation (adjacent Namaleta Creek) G4 Bulimba Formation (adjacent Namaleta Creek) G5 Bulimba Formation G6 Bulimba Formation n/a n/a n/a G7 Bulimba Formation G8 Bulimba Formation G9 Bulimba Formation G10 Bulimba Formation G11 Bulimba Formation n/a n/a n/a G12 Bulimba Formation (adjacent n/a n/a n/a Namaleta Creek) G13 Bulimba Formation (adjacent n/a n/a n/a Namaleta Creek) G14 Bulimba Formation (adjacent n/a n/a n/a Namaleta Creek) C1 Rolling Downs Siltstone C2 Rolling Downs Siltstone C3 Rolling Downs Siltstone n/a = not enough valid data to determine the response Page 12-36

41 Figure Standing Groundwater Level Bore C1 Figure Standing Groundwater Level Bore G Groundwater Quality The results of groundwater quality testing are tabulated and graphed in Appendix 4. Groundwater quality results are presented for all aquifers in combination and the different aquifers which are intersected by the bores, namely Bulimba Formation (Namaleta Creek) aquifer, Bulimba Formation aquifer and Rolling Downs Siltstone aquifer. Page 12-37

42 The bulk of the groundwater quality data has been obtained during a four month period of Thus, there is insufficient data to propose statistically valid site specific trigger values in accordance with the AWQG. Despite this, there is sufficient data to make an initial interpretation of the groundwater quality onsite Physical Parameters The physical parameters determined from the groundwater monitoring have been summarised in Table 12-16, Table 12-17, Table and Table for the three different aquifer groupings. ph is slightly acidic in all aquifers, ranging from 4.8 to 6.2 ph units. The weakly acidic ph is a reflection of the geology of the site. EC is low, ranging from 22 to 196 µs/cm. Bores within the Bulimba Formation aquifer have the lowest mean EC (59 µs/cm), with bores in the Rolling Downs Siltstone aquifer have mean EC (74 µs/cm), and the bores within the Bulimba Formation aquifer adjacent to Namaleta Creek have highest mean EC (126 µs/cm). Of the bores intersecting the Bulimba Formation aquifer, bores G3, G5, G12 and G13 have elevated EC (>100 µs/cm) when compared with the remainder of the bores. This may be due to their proximity to tidally influenced portions of Namaleta Creek (G3, 12, 13, 14) and Skardon River (G5). Table Groundwater Physical Parameter Summary Results All Bores Bores Statistical ph (ph units) EC (µs/cm) TDS DO Redox (mv) Element All Bores minimum maximum mean median th percentile n th percentile 5.30 Table Groundwater Physical Parameter Summary Results Bulimba Formation (Namaleta Creek) Aquifer Bores Statistical ph (ph units) EC (µs/cm) TDS DO Redox (mv) Element G3, G4, G12, minimum n/a n/a G13, G14 maximum n/a n/a mean n/a n/a median n/a n/a 80th n/a n/a percentile n n/a n/a 20 th percentile 5.16 n/a = not enough samples for valid statistics Page 12-38

43 Table Groundwater Physical Parameter Summary Results Bulimba Formation Aquifer Bores Statistical ph (ph units) EC (µs/cm) TDS DO Redox (mv) Element G1, G2, G5, minimum G6, G7, G8, maximum G9, G10, G11, mean C1 (shallow), median C2 (shallow), 80th C3 (shallow) percentile n th percentile 5.2 n/a = not enough samples for valid statistics Table Groundwater Physical Parameter Summary Results Rolling Downs Siltstone Aquifer Bores Statistical ph (ph units) EC (µs/cm) TDS DO Redox (mv) Element C1, C2, C3 minimum n/a n/a maximum n/a n/a mean n/a n/a median n/a n/a 80th n/a n/a percentile n n/a n/a 20 th percentile 5.46 n/a = not enough samples for valid statistics Metals Monitoring data for selected metals has been obtained, and is summarised in Table 12-20, Table Table and Table for all bores and the three aquifer groupings. Dissolved metals values are very low across almost all bores in all aquifers, when compared with the AWQG trigger values. One exception is dissolved copper, which is elevated across all aquifers and has a maximum of mg/l (compared to mg/l per the AWQG). Values of copper appear highest in the Rolling Downs Siltstone aquifer. The other exception is dissolved zinc, which is which is elevated across all aquifers and has a maximum of 1.17 mg/l (compared to mg/l per the AWQG). Values of zinc appear highest in the Rolling Downs Siltstone aquifer. It is considered that these values of metals reflect the geology of the site. Page 12-39

44 Bores Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn All Bores minimum n/a n/a maximum n/a n/a mean n/a n/a median n/a n/a th percentile n/a n/a n Page Table Groundwater Dissolved Metals Summary Results All Bores n/a = results all below the detection limit, or not enough results for valid statistics Table Groundwater Dissolved Metals Summary Results Bulimba Formation (Namaleta Creek) Aquifer Bores Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn G3, G4, G12, G13, minimum n/a n/a n/a n/a G14 maximum n/a n/a n/a n/a mean n/a n/a n/a n/a median n/a n/a n/a n/a th percentile n/a n/a n/a 0.09 n/a n n/a = results all below the detection limit, or not enough results for valid statistics Table Groundwater Dissolved Metals Summary Results Bulimba Formation Aquifer Bores Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn G1, G2, G5, G6, G7, G8, minimum n/a n/a n/a n/a n/a G9, G10, G11, C1 maximum n/a n/a (shallow), C2 (shallow), mean n/a n/a n/a n/a n/a median n/a n/a n/a n/a n/a th percentile n/a n/a n/a n/a n/a n n/a = results all below the detection limit, or not enough results for valid statistics

45 Bores Statistical Element Al As Cd Cr Cu Fe Pb Mn Hg Ni Zn C1, C2, C3 minimum n/a n/a n/a n/a n/a maximum n/a n/a mean n/a n/a n/a n/a n/a median n/a n/a n/a n/a n/a th percentile n/a n/a n/a n/a n/a n n/a = results all below the detection limit, or not enough results for valid statistics Page Table Groundwater Dissolved Metals Summary Results Rolling Downs Siltstone Aquifer

46 Nutrients Monitoring data for total nitrogen and total phosphorus has been obtained, and is summarised Table 12-24, Table 12-25, Table and Table for the three aquifer groupings. Nutrient values (TN, TP) are low across all bores, with no appreciable difference between aquifers. There are limited test results for nutrients, and additional sampling over time may lead to discernible differences being noted. Table Groundwater Nutrient Summary Results All Bores Bores Statistical Element Nitrogen (total) (mg/l N) Phosphorus (total) (mg/l P) G3, G4, G12, G13, G14 minimum maximum mean median th percentile n Table Groundwater Nutrient Summary Results Bulimba Formation (Namaleta Creek) Aquifer Bores Statistical Element Nitrogen (total) (mg/l N) Phosphorus (total) (mg/l P) G3, G4, G12, G13, G14 minimum maximum mean median th percentile n 8 8 Table Groundwater Nutrient Summary Results Bulimba Formation Aquifer Bores Statistical Element Nitrogen (total) (mg/l N) G1, G2, G5, G6, G7, G8, G9, G10, G11, C1 (shallow), C2 (shallow), C3 (shallow) Table minimum maximum mean median th percentile n Groundwater Nutrient Summary Results Rolling Downs Siltstone Aquifer Phosphorus (total) (mg/l P) Bores Statistical Element Nitrogen (total) (mg/l N) Phosphorus (total) (mg/l P) C1, C2, C3 minimum maximum mean median th percentile n Potential Impacts, Emissions and Releases The potential impacts to surface water quality are: Page 12-42

47 uncontrolled release of water with high sediment loads from bauxite mining areas uncontrolled release of water with high sediment loads from haul roads, including the Namaleta Creek crossing area increased sedimentation of waterways during construction and vegetation clearing uncontrolled release of potentially hydrocarbon and chemical contaminated water from infrastructure areas. The potential impacts to groundwater quality are: localised impacts to groundwater quality hydraulically down-gradient from the landfill, treated effluent irrigation area and bio-remediation pad through seepage uncontrolled release of potentially hydrocarbon and chemical contaminated water from infrastructure areas saline water ingress resulting from extraction of water from kaolin storages, borefield pumping for Project water supply and mining of pits. Chapter 13 describes potential impacts to surface water hydrology and groundwater hydrogeology Mitigation and Management Measures Water management for the Project is described in Chapter 6 and the management measures relevant to mitigating potential impacts described in Section 12.8 and achieving the environmental objectives and performance outcomes described in Section 12.2 are described below. Kaolin mine water management is undertaken in accordance with the conditions of the existing EA and the kaolin mine s Plan of Operations. Kaolin mine water management has been incorporated in the EM Plan (Appendix 13). The proposed groundwater and surface water monitoring programmes are described in Section Mine Pits During operational periods, it is intended that rainfall runoff entering the pit will be drained internally and contained within the pit, to be lost as evaporation and as recharge to local aquifers. The need for any sediment ponds external to pits will be determined during ongoing mining operations and may only be required in the unlikely event that the pre-mining topography does not allow for internally draining pits. Mine pits are shown in Chapter 5, Figure Due to the nature of bauxite mining (shallow pits to approximately 6 m depth, located at the top of localised catchments and hydrogeology of pit areas allowing seepage from pits) there is no requirement for external storage and release of water captured within pits. Surface water runoff does not occur as long as the mine floor lies below the surrounding terrain. Stormwater drains through the groundwater system. This process is enhanced by deep ripping of the mine floor, which will occur prior to the wet season in most bauxite mining areas. Placement of soil and bauxite waste on the mine floor will be even and parallel to the mine floor topography, which should be closely parallel to the original land surface. The edges of mining areas will be battered down to a 3:1 slope and re-vegetated as for the mine floor. Erosion within mined areas is negligible due to the generally flat or gently sloping terrain. To prevent surface water runoff from mining areas, or to minimise runoff, in the unlikely event of it occurring, the following measures will be adopted for erosion and sediment management: Page 12-43

48 Clearing and mining will not be carried out in areas of steep drop-off slope from the general terrain expected generally to be within 100 m of natural waterways and swamps. Ripping will be conducted along contour lines, or offset to direct water away from valleys, using Keyline principles (i.e. management of the topography to control runoff). Should a low area be (erroneously) mined on the edge of a mining area, with potential to allow outflow of stormwater, earth bunds and silt traps will be constructed, as well as strategic contour banks on the mine floor to direct flow away from the area. All structures would be stabilized with establishment of grass cover, trees and shrubs. Prior to mining, detailed resource surveys will be undertaken to inform the precise location of economic bauxite resources. This is expected to result in accurate delineation of pits areas which avoid: buffer zones around wetland and watercourses (refer to Chapter 15) low lying areas with the potential to require erosion and sediment control measures to prevent outflow from pits unnecessary clearance of vegetation in areas that will not be mined. Land clearing in advance of mining will be undertaken in the dry season. Gulf Alumina is likely to undertake annual vegetation clearing, windrowing and burning in advance of proposed mining, with areas to be cleared subject to ongoing review of the proposed areas of mining. Mining will generally occur in the same year (i.e. during the dry season) and therefore there is limited potential for erosion following clearing activities. Following clearing and prior to mining, these areas will be stabilised by allowing regrowth of grasses and shrubs and to maintain viability of the soil for plant growth. Should any cleared areas not be mined within the same dry season, these cleared areas will be bunded along a perimeter track surrounding the cleared areas. Where there is a risk of increased sedimentation from areas cleared of deep rooted vegetation, erosion and sediment control structures will be installed Mine Site Sediment Management The topography of the Project area is shown in Chapter 10 and is generally low lying and flat with topography rising towards a ridge where bauxite deposits are located. The Project mining leases are at around 5 20 mahd elevation where bauxite deposits occur, 3-8 mahd at the Port infrastructure area and lower in creek and wetland areas. The bauxite pits are located at the top of the local catchments and hence external catchments reporting to the pits will be minimal. Under the proposed mining approach, there will be no sediment runoff from mining areas to surrounding land and waters as runoff will be managed within the pits. Sediment ponds receiving drainage from the disturbed mining areas will be managed in pit. Design will be carried out in accordance with best practice approaches and as part of an Erosion and Sediment Control Plan (ESCP). The ESCP will be developed in line with the IECA Manual which provides guidelines for erosion control on site, sediment pond design and construction, and their operation and maintenance. The design and management details for in pit sediment ponds will be determined as an ongoing operational activity. However, preliminary estimates have been made for the sediment runoff volumes, and indicative geometric requirements for the expected sediment ponds within each pit. As described in Appendix 4, pond sizing was completed using the CALM approach. The approach depends on the erodibility of soil, peak runoff discharge and the volume of sediment likely to enter the structure. The basin surface area is determined as a function of the inflow rate and the target particle settling velocity. The estimate catchments areas for each pit, sediment runoff volume and in-pit pond sizes and are provided in Table Nominal sediment basin volumes range between 400 m 3 and m 3 with minimum storage depth requirements of between 2.0 and 2.3 m. This depth requirement could be Page 12-44

49 reduced further, subject to pond management practices, with regular scouring and dredging to maximise containment volumes. The nominal in-pit pond size is approximately 0.5% of the pit catchment area for each pit. It is clear that in-pit sediment ponds will occupy a minor portion of each pit and that the pit itself will act to capture any runoff should the sediment basins overtop. Table Pit Local Catchment Area (ha) Catchments Areas, Sediment Runoff and Pond/Dam Sizing Sediment Volume (m 3 /y) Nominal Area (m2) Pond Minimum Storage Depth (m) Pit Pit Pit Pit Pit Pit Pit Pit Pit Pit Pit Pit Pit Pit Pit Mine Site Sediment Pond Management Pond Volume (m 3 ) The sediment ponds will be used opportunistically to meet local demand for water (e.g. dust suppression) thereby reducing the need for supply from other sources (e.g. shallow aquifer bores). For the dual purposes of containing sediment on site for controlled disposal and for providing low quality water supply, sediment and erosion control measures will include: regular inspection of the sediment storage structures conducted at the conclusion of the wet season (typically in April-May). inspection of sediment ponds to establish the condition and stability of rock walls and spillways (applicable to Port sediment ponds described below). monitoring of sediment deposition volumes and identification if a clean out is required to provide sufficient storage for sediment loading in runoff and improve storage availability where sediment ponds are in use for dust suppression. Clean out will be completed immediately prior to the wet season, and sediment will be disposed of in a location where erosion will be limited or contained (e.g. mining areas undergoing rehabilitation), and will not contribute to sediment loads reporting to other control structures. Page 12-45

50 Port Infrastructure Area Skardon River Bauxite Project One or more sediment ponds will be located at the Port infrastructure area to capture runoff from disturbance areas, including the bauxite stockpile, paved areas, workshops and haul roads. Sediment ponds based on the two Port layouts (refer Chapter 5), are shown in Figure 12-13, which also shows runoff flow paths and drainage control structures Under Option 1, there is an existing sediment pond which may be decommissioned or refurbished for the Project or, alternatively a new sediment pond may be constructed adjacent to the existing pond as a replacement. Under Option 2 a new sediment pond would be required to the north of the existing Port infrastructure and the existing sediment pond is likely to be retained. All sediment pond options are located to capture runoff from the Port infrastructure area. Page 12-46

51 ± Proposed Haul Road Loop 4 3 S14 New Port Sediment Dam 1.5 Wharf Bunded Landfill and Bioremediation Pad Existing Haul Road Bauxite Stockpile Proposed Haul Road Loop 6 Bauxite Stockpile 7 Conveyor Drainage Dry Plant Area 5 New Port Sediment Dam Drainage Conveyor Fuel Storage Tank S ( Wharf New Port Sediment Dam ML Meters Legend Mining Lease Boundaries Port Infrastructure Area Wharf and Port Plan Options Option 1 Option 2 Both Options Port Area Sediment Dam Release Points Conceptual Overland Flow Path 0.5m Contours Port Area Sediment Ponds and Drainage Figure Date: 7/10/2015 Author: malcolm.nunn Map Scale: 1:6,000 Gulf Alumina Limited Drainage Control Revision: R1 Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_13_Port_Layout_Conceptual_Flow_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy law Imagery supplied by Gulf Alumina (2014). Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006).

52 Based on a preliminary risk assessment (refer to Chapter 6), the Port area sediment ponds are not expected to be regulated dams. Following detailed design, and prior to the design and construction of the structure, the Port area sediment ponds will be subject to a regulated dam assessment by a suitably qualified and experienced person in accordance with the Manual for Assessing Consequence Categories and Hydraulic Performance of Structures (EHP, 2014). A consequence assessment report and certification will be prepared for each structure assessed. Port area sediment ponds will be designed by an appropriately qualified person. On the basis that Port sediment ponds are not expected to be regulated structures, the nominal design is for a 1:10 year annual exceedance probability (AEP), 24 hour rainfall event, subject to refinement during detailed design. Port area sediment ponds will have a spillway that is designed, constructed and effectively armoured to convey anticipated flows, with a nominal minimum design for a 50 year annual recurrence interval (ARI) rainfall event, subject to refinement during detailed design. The nominal pond area allowed for in the conceptual layout of Port infrastructure allows for a sediment pond of at least 6000 m 2. From a sediment assessment based on the CALM method (refer to Appendix 4) for a 6 hour, 1 in 10 year storm event, the minimum pond area requirement for retention is estimated to be 673 m 2, demonstrating that the nominal pond area has been adequately sized. Runoff from the Port infrastructure area will be concentrated in drainage channels flowing to the sediment ponds. These drainage channels will be designed, constructed, armoured and maintained to maintain the runoff from all storm events up to an including a 1 in 10 year ARI rainfall event without causing erosion and sedimentation. The sediment pond(s) at the Port will capture and retain runoff from the Port infrastructure area and during normal operation, will retain water in line with design guidelines to remove sediment to desired levels before controlled release. Release events will occur during rainfall events that exceed the design capacity of the sediment ponds, when there will be naturally high levels of turbidity in the receiving environment. Port area sediment ponds will minimise impacts on the Skardon River by: discharging through the nominated spillway managing releases to prevent scouring (e.g. rock spillways) maximising the distance through which discharges flow through vegetation prior to entering the Skardon River. Should the Port area sediment pond(s) overtop, water will drain through an area of vegetation prior to entering the Skardon River estuary. The environmental values of the Skardon River estuary are described in Chapter 17 Coastal Processes and Chapter 18 Marine Ecology. Given the scale of the estuary compared to the scale of the Port area sediment pond(s), and high natural variation in estuary turbidity, any releases from the sediment pond are likely to have a minimal impact on the marine environment. Release events would only occur under a rainfall event that exceeds the design criteria when natural sediment loads in runoff would be high. Sediment from the pond will be removed twice per year, and at least before the wet season, allowing maximum storage capacity for settling and containing suspended solids during the wet season. Sediment levels will be inspected in ponds following rainfall events resulting in runoff (e.g. 20 mm in 24 hours), which may result in further sediment removal so that the required design capacity is available from the next rainfall event. Sediment that is removed will be taken to an area where sediments will be contained, such as an open mining area. Other measures to manage erosion and sediment runoff at the Port infrastructure area include: paving of some areas Page 12-48

53 short term measures such as surface roughening of exposed areas particularly during periods of high risk for erosion (likely to occur during construction) long term prevention of erosion using control techniques such as revegetation and gravelling (which limits the impact of raindrops and generation of mud). Port sediment ponds will be located above the 1:100 year flood level for the Skardon River as described in Chapter 14. This pond(s) will not be more than 10 m in height and hence does not require a failure impact assessment under the Water Supply (Safety and Reliability) Act Bauxite Stockpile Sediment Control The stockpile will be gradually depleted over the year and decreased to zero in January so that no stocks are held during the wet season. This will prevent runoff from the stockpile over the wet season. Neverthe-less the stockpile will be bunded and any runoff from the bauxite stockpile will be directed towards a sediment trap / sediment check dam system. This will consist of drains, incorporating rock lining as required, around the bauxite stockpile which direct runoff to an interceptor system. Sediment from the interceptor will be removed regularly, including after rainfall events. Outflow from the interceptor system will be directed to the port sediment ponds, thereby reducing the volume of sediment reporting to the sediment ponds Contaminant Management Measures to prevent contamination of surface water and groundwater from hydrocarbons and chemicals in infrastructure areas, and from the landfill and bio-remediation pad are described in Chapter 11. Chapter 11 describes monitoring of groundwater up gradient and down gradient of the landfill and bio-remediation pad and hydrocarbon storage, including monitoring locations, frequency, parameters and contaminant limits. The landfill and bio-remediation pad will be bunded to prevent ingress of runoff and prevent outflow of potentially contaminated water from direct rainfall. Waste management at the Port infrastructure area is described in Chapter 8. These measures (e.g. bunds, oily water separators) are intended to prevent runoff to sediment ponds containing hydrocarbons, chemicals and other pollutants. Therefore any releases from the sediment ponds are not expected to contain elevated levels of hydrocarbons or chemicals Release Monitoring Sediment depths in Port sediment ponds will be inspected at least biannually, prior to the wet season, following the wet season and after any significant rainfall events. Sediment will be removed and transferred to an open mining area, should sediment depth compromise the design standards of the dams. Release points from Port area sediment ponds will be located at the downslope end of these structures, for which coordinates are provided in Table 12-29, based on the conceptual Port area design. These coordinates are subject to change during detailed design and any approvals will be amended accordingly to reflect changes. The existing EA nominates release point W2 at the Port as the discharge point from stormwater drains on the bank of the Skardon River. This EIS replaces this monitoring location with monitoring of the release point from the existing sediment pond, which more accurately reflects existing and proposed water management at the Port area. Note that Table provides release points for the existing sediment pond and a new sediment pond (Port option layout 1) to replace the existing sediment pond, if required. It is unlikely that both sediment ponds will be required and hence this release point is referred to as S13. Page 12-49

54 Release points have been situated as far away from Skardon River as possible given the constraints of collecting runoff downstream of Port infrastructure, above the Skardon River flood zone, and with 50 m to 100 m separation distance to the Skardon River. Release points will have a shallow contour drain leading away from the dams, so that water spreads over a native vegetation area between 50 m and 100 m from the Skardon River. This will result in dissipation of flows and a reduction in velocity and erosion potential. Table Release Point S13 Discharge point from the existing Port sediment pond S13 Proposed sediment pond Option 1 (adjacent to existing sediment pond) S14 - Proposed sediment pond Option 2 Release Points Port Area Sediment Ponds Reference per existing EA W2 - Discharge point from stormwater drains on the bank of the Skardon River Easting Northing Monitoring Frequency Within 24 hours of any discharge from S13 (formerly W2) and thereafter weekly whilst discharging n/a Within 24 hours of discharge and thereafter weekly whilst discharging. n/a Within 24 hours of discharge and thereafter weekly whilst discharging. During a release event, monitoring will commence with 24 hours of a release event (subject to safe access) and releases will be monitored weekly until releases cease. Release will be monitored for the following parameters: physico-chemical nutrients metals total petroleum hydrocarbons oil and grease. The proposed release limits for the Port sediment ponds are provided in Table 12-30, and are based on the preliminary marine water quality objectives presented in Chapter 17. Table Release Limits Parameter Units Release Limit Turbidity NTU Turbidity maximum as identified through monitoring at site S16 prior to any release. Electrical Conductivity µs/cm ph ph units Total nitrogen µg/l 1000 No visible plume in Skardon River Salinity maximum as identified through monitoring at site S16 prior to any release. Page 12-50

55 Parameter Units Release Limit Total phosphorus µg/l 60 Aluminium µg/l 220 Arsenic µg/l 92 Cadmium µg/l 0.35 Chromium µg/l 4.9 Copper µg/l 3.9 Iron µg/l 274 Mercury µg/l 0.1 Nickel µg/l 12.5 Lead µg/l 2.5 Zinc µg/l 38 Petroleum hydrocarbons (C6-C9) Petroleum hydrocarbons (C10-C36) µg/l 20 µg/l 100 Oil or grease n/a No visible film or detectable odour to Skardon River Skardon River Bauxite Project Effluent Irrigation Area Chapter 8 describes treated effluent management, including release conditions to minimise the potential for impacts to land and waters. Chapter 8 describes monitoring of groundwater up gradient and down gradient of the treated effluent irrigation area, including monitoring locations, frequency, parameters and contaminant limits Erosion and Sediment Control Other than the Port infrastructure area and mining areas, erosion and sediment control measures will be implemented at: construction areas permanent haul roads haul road crossing of Namaleta Creek and other drainage features Erosion and Sediment Control Plan An erosion and sediment control plan (ESCP) will be developed for the Project prior to commencement of construction and mining activities and will cover all aspects of the Project including clearing, construction, operations, rehabilitation and decommissioning. The ESCP will be approved by a suitably qualified person 1 (such as a Certified Professional in Erosion and Sediment Control). The ESCP will be 1 For example, an appropriately qualified person as defined in Stormwater guideline Environmentally relevant activities (EHP, 2014) Page 12-51

56 amended as the mine develops to account for changes in final landform design and infrastructure locations. An ESCP will be developed in accordance with the: recommended guidelines of the International Erosion Control Association (IECA) Manual (IECA, 2008) Soil Erosion and Sediment Control-Engineering Guidelines for Queensland Construction Sites (Witheridge and Walker, 1996) Stormwater guideline Environmentally relevant activities (EHP, 2014) The most critical aspects of the ESCP are set out below. An assessment of erosion risk will be undertaken for different parts of the Project area. Soil types will be assessed (refer Chapter 10), including identification of erosion potential. Soil will be managed in accordance with the measures described in Chapter 10 for soil stripping, handling, stockpiling and testing. Development of the ESCP will be integrated into the mine planning process. Sensitive areas (e.g. buffer zones around watercourses and wetlands) that may require specific measures to prevent sedimentation will be identified. The period of maximum disturbance will be planned to occur in the dry season. Construction activities and land clearing will be undertaken in the dry season. The extent and duration of disturbance (topsoil and subsoil exposure) will be minimised. Boundaries of areas to be cleared will be delineated and clearing will be authorised by use of a permit to clear system. Grubbing out and removal of ground cover will be carried out as close to the time of mining or earthworks as possible. Stabilisation of areas cleared in advance of mining will occur through allowing regrowth of grasses and shrubs. Stormwater runoff from external or undisturbed catchments will be diverted around or away from infrastructure construction areas. Uncontaminated stormwater run-off will be diverted around areas disturbed by Port infrastructure area activities or where contaminants or wastes are stored or handled. All drainage structures and sediment controls will have design specifications appropriate to the rainfall regime and design life. Erosion controls will be used to minimise sediment generation and transport. Sediment controls will be used to treat run-off from disturbed areas prior to leaving the site. Sediment controls will be located as close to the source as possible. Erosion and sediment control structures will be installed as required, prior to disturbance in that area of site. Disturbed areas will be stabilised as soon as possible (progressively rehabilitated). Control structures will be inspected regularly. Details of the rehabilitation of the site, including final landform design is provided in Chapter 7. Rehabilitated landforms will be designed to minimise slope angle and length. Erosion loss decreases exponentially with percentage ground cover and is greatly reduced when cover exceeds 50%. For long- Page 12-52

57 term stabilisation in tropical climates, IECA (2008) recommends a minimum ground cover of 80% which will considered as the target for this Project. Vegetation establishment will be required for long-term soil stabilisation. All revegetated areas will be monitored to ensure the desired ground cover is achieved and further seeding or planting is conducted in areas that do not meet the desired target. Chapter 15 and Chapter 16 described the proposed vegetation buffer zones around wetlands, watercourses and drainage features. These buffer zones will act to reduce potential impacts from sediment laden runoff. Erosion mitigation measures specifically relevant to waterways include the following: Where earthworks are carried out in proximity to a watercourse, disturbance will be stabilised. Felled timber will be removed from the area and stockpiled away from the watercourse. Where required temporary controls will be installed along cleared slopes approaching watercourses, to divert dirty water away from the watercourse. Clean rock and culverts will be used for temporary watercourse crossings Water discharged to a waterway will meet Project water quality objectives. The ESCP may include measures such as: velocity slowing methods including rock and log placement in cleared areas restriction of land disturbance scour protection design methods for drainage rehabilitation practices to limit erosion. The ESCP will be implemented for construction and throughout operations. Drainage and erosion control will be implemented as a part of operational activities using measures such as erosion control blankets, check dams, filter fences and rock mattresses. Monitoring of erosion and sediment control structures will be carried out both pre- and post-wet season and following any significant events. Monitoring may be done using visual methods (such as those for recording erosion features) and/or more quantitative methods such as those using erosion monitoring pins, or measuring sediment loads from monitored catchments. Monitoring of erosion and sediment controls may include: visual inspections undertaken regularly and following significant rainfall e.g. 20 mm in 24 hours daily monitoring of weather predictions to manage clearing and construction activities. completion of site inspection checklist supervisors to visually monitor all operations and identify where correct procedures are not being followed contractors to monitor works and should they become aware of improper management practices, to report the issue to their supervisor. site supervisors will be responsible for modifying or stopping non-conforming management practices until corrective actions are determined corrective and preventive actions to be implemented and monitored visually on site to ensure they are effective Permanent Haul Roads Permanent haul roads (i.e. the main haul road connecting the Port area to the mining areas to the south) will be designed in consideration of the Department of Transport and Main Road s (TMR s) Road Page 12-53

58 Drainage Manual (TMR, 2015). This provides technical guidance on road drainage, erosion, environmental and sediment control Namaleta Creek Crossing Location The location of the proposed crossing of Namaleta Creek is shown in Figure This is the same location as the existing crossing Existing Crossing The existing crossing of Namaleta Creek crossing consists of an earthen crossing (10 15 m wide), where two cylindrical pipes connect the upstream and downstream reaches of Namaleta Creek. These existing pipe culverts may be impacting flows and fish passage. The section of road currently crossing the southwestern flood plain of Namaleta Creek (refer to Figure 12-14) is restricting normal flow during the height of the wet season Crossing Design The crossing will be upgraded to support haul truck movements between mining areas to the south of Namaleta Creek and the Port. The corridor associated with the proposed upgrade of the crossing will be 40m at the widest point requiring an additional 25m of clearing. The design of the crossing will be in accordance with the Department of Agriculture and Fisheries Code for Self-assessable Development Minor Waterway Barrier Works, Part 3 Culvert Crossings, Code Number: WWBW01 April 2013 (the Code). This Code is designed to minimise impacts to fish passage. In this respect the upgraded crossing will result in the hydrology of the area more closely resembling its pre-disturbance condition. Additional culverts will be inserted in the section of road crossing the flood plain to restore free flow of wet season water. A schematic cross-section of the Namaleta Creek crossing is shown in Figure The culverts and deck level of the crossing were sized for a 1:50 year AEP design flood standard. Figure shows the preliminary sizings of the culvert groupings proposed to convey water through the haul crossing embankment, as applied in the model. Note that the culverts are distorted by the aspect ratio of the cross-section. Page 12-54

59 Queensland CAIRNS TOWNSVILLE ± ROCKHAMPTON BRISBANE NAMALETA CREEK Namaleta Creek Crossing Pit # Meters 8.5 Legend ( Port of Skardon River Mining Lease Boundaries Watercourses Existing Disturbance Footprint Project Footprint Haul Road Crossing Elevation Contours (0.5m) Queensland Waterways for Waterway Barrier Works Risk of Impact 2 - Moderate (Streams) Namaleta Creek Crossing Location Figure Date: 7/10/2015 Revision: R1 Author: malcolm.nunn Map Scale: 1:4,000 Gulf Alumina Limited Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_14_Namaleta_Crossing_Contours_WWBW_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery sourced from Gulf Alumina. Waterways for Waterway Barrierworks State of Queensland (Department of Agriculture and Fisheries) 2015.

60 Figure Namaleta Creek Crossing Downstream View Preliminary sizing of the culvert groups and bridge deck level required at the crossing was carried out with reference to the guidelines and recommendations of the Road Drainage Manual, Department of Transport and Main Roads, July 2015 (TMR-RDM). Detailed design will be carried out in compliance with the TMR-RDM and with: Roads in the Wet Tropics Manual, Transport and Main Roads, 1998) design detail requirements of the Code for Self-Assessable Development; Minor Waterway Barrier Works Part 3: Culvert Crossings, Code number: WWWBW01 (April 2013), Department of Agriculture, Fisheries and Forestry (DAFF). The following specific conditions are noted from the Code for addressing moderate impact waterways (applicable to Namaleta Creek): Works must commence and finish within a maximum time of 360 calendar days and instream sediment and instream silt control measures associated with the works must be removed within this period. The crossing must have a minimum (combined) culvert aperture width of 2.4 m or span 100% of the main channel width. All new or replacement culvert cells must be installed at or below bed level. The internal roof of the culverts must be >300 mm above the commence to flow water level. Where the cell is installed at less than 300 mm below bed level (potentially the case for the Namaleta Crossing), the culvert floor must be roughened throughout to approximately simulate natural bed conditions. The culvert must be installed at no steeper gradient than the waterway bed gradient. Apron and stream bed scour protection must be provided in line with the design requirements of the Code. It is expected that the Code requirements can be met for the Namaleta crossing design Crossing Drainage Drainage from road surface of the crossing will be directed to the ends away from the Creek, by peaking the height of the crossing at its centre and raising the entire crossing above the elevation of the surrounding topography. Thus stormwater runoff will drain to the entry points of the crossing approximately 50 m to 100 m from the Creek bank. Silt traps will be installed at the end of the drains Page 12-56

61 and over flow directed into contour drains. On the south-west side this water will flow into natural vegetation while on the north-east side water will be directed into kaolin mine revegetation areas, or kaolin mine water storages Crossing Construction and Rehabilitation To prevent any instream impacts including sedimentation to Namaleta Creek and the mapped HES wetland during the construction of haul road crossing, construction activities will be scheduled for the dry season, when the potential for impact is minimised due to low or no flow conditions when temporary impoundments are not expected to be required when working within the in-stream environments. This strategy is also part of avoiding disturbance of acid sulphate soil, the management of which is described in Chapter 10. With construction of the proposed crossing within a single dry season, temporary changes to the drainage and flow regimes will be avoided and Creek flow will be improved from the current situation in the following wet season. Construction work within Namaleta Creek will ensure that all surfaces are adequately stabilised following the completion of the haul road crossing. This will include revegetation of exposed embankment areas and mulching if necessary until stream banks have stabilised. A significant level of vegetation clearing and landform modification has occurred on the northern side of Namaleta Creek as a consequence of the former kaolin clay mine operation. The resilience of the Melaleuca-dominated vegetation of this wetland has the capacity to regenerate rapidly, and form a functional and protective vegetation cover within a relatively short period, and this would be expected for the crossing upgrade. The crossing will be constructed with ironstone material from the borrow pits over a claystone core, using material from the kaolin claystone overburden stockpile Crossings of other Drainage Features The haul road will cross a drainage feature between Pits 14 and 15 to the south of Namaleta Creek, as shown in Figure This drainage feature is mapped as moderate risk for waterway barrier works. The design of the crossing will be determined following inspection of the area, including drainage, and extent and width of any potential wetland features (if wetland is found to be associated with this area). The design of the crossing will be in accordance with the Department of Agriculture and Fisheries Code for Self-assessable Development Minor Waterway Barrier Works, Part 3 Culvert Crossings, Code Number: WWBW01 April Crossing construction will follow the methodology described for the Namaleta Creek crossing. Culverts will maintain natural flow of stormwater in the drainage feature and the road surface drainage system will direct flow away from drainage feature. All works required within the drainage feature will ensure that all surfaces are adequately stabilised following the completion of the haul road construction. This will include revegetation of exposed embankment areas and temporary erosion and sediment control until construction is completed or drainage feature banks have been stabilised. Page 12-57

62 ± CAIRNS TOWNSVILLE Queensland 7 ROCKHAMPTON 8 BRISBANE Pit # Drainage Feature Crossing Pit # Pit # Meters Legend ( Port of Skardon River Mining Lease Boundaries Watercourses Existing Disturbance Footprint Project Footprint Haul Road Crossing Elevation Contours (0.5m) Queensland Waterways for Waterway Barrier Works Risk of Impact 2 - Moderate (Streams) Figure Date: 7/10/2015 Revision: R1 Haul Road Crossing of Drainage Features Author: malcolm.nunn Map Scale: 1:4,000 Gulf Alumina Limited Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_16_Drainage_Crossing_Contours_WWBW_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery sourced from Gulf Alumina. Waterways for Waterway Barrierworks State of Queensland (Department of Agriculture and Fisheries) 2015.

63 12.10 Proposed Surface Water and Groundwater Monitoring Programme A baseline monitoring programme, as described in Section 12.6 (surface water) and Section 12.7 (groundwater) has been established by Gulf to provide data for surface water quality, surface water depth, groundwater quality and groundwater level. This data has been used to establish baseline conditions and understand natural variations. These sites will continue to be monitored to detect potential Project impacts during construction and operations. The intention is to expand the monitoring network prior to construction and operations, as described below. The following areas are currently monitored in line with the EA requirements for the kaolin mine: receiving waters affected by the release of process water and/or stormwater potentially contaminated by former kaolin mining activities (approximately 100m upstream and 100m to 500m downstream of the existing water storages) contaminants from end of pipe release points from kaolin mine water storages (discharge points from the Raw Water Pit, western sump of Fluvial Pit, south side of Namaleta Creek and stormwater drains on the bank of the Skardon River at the Port) effluent released from the treatment plant at the camp to be released to the effluent irrigation area groundwater potentially affected by former kaolin mining activities. Proposed groundwater and surface water monitoring programs for the Project (i.e. bauxite mining) are outlined in this section. Other monitoring related to water parameters will include ongoing recording of weather parameters (rainfall and evaporation), water consumption and flow rates. It is proposed to modify the monitoring programme and the existing EA conditions such that they continue to apply to the former kaolin mine activities as well as future bauxite mining activities. Ongoing monitoring will be conducted in order to establish local water quality objectives prior to commencement of mining activities Surface Water Monitoring Locations Monitoring of surface water has been carried out at several sites on Namaleta Creek, Skardon River, Lunette Swamp and Bigfoot Swamp, as described in Section The current EA specifies surface water monitoring for the decommissioned kaolin mine. This monitoring will continue during the Project and will provide information to understand potential impacts of the kaolin mine and the Project and is described in Table Ongoing surface water monitoring at the sites described in Section 12.6 is proposed for the Project to supplement current surface water monitoring. The proposed monitoring locations and function of each location are described in Table and shown in Figure Surface water monitoring will be for water quality, water levels in swamps and in receiving waterways, and for flows in the receiving waterway. The surface water monitoring programme will collect water quality samples on a quarterly basis prior to mining in order to establish robust baseline conditions that can inform setting local water quality objectives in accordance with the QWQG. The catchments and drainages surrounding the Project area are small and comprise a mix of freshwater and estuarine water. The design of the monitoring programme involves three distinct catchment zones: Skardon River South Arm and supratidal wetland Drainages and wetlands downstream of the central mining areas including Lunette Swamp and Bigfoot Swamp Page 12-59

64 Namaleta Creek catchment, including downstream of the intersection of with the EHP mapped wetland drainage feature between Pits 14 and 15 (that is not interpreted to be a wetland). Page 12-60

65 Page Table Existing and Proposed Surface Water Monitoring Network Monitoring Point Name per Current EA # Location Details Site Function Kaolin Mine S1 n/a Namaleta Creek upstream of bauxite mining S2 Namaleta Creek Upstream 100 m upstream of existing crossing S3 W1 Discharge point from the Raw Water Pit Site Function Bauxite Project Depth Logger Installed Reference Site Reference site quality, depth and flows. Reference site Reference site - downstream of Pits 12 and 14 during mining. Prior to mining, upstream of kaolin mine and hence provides baseline data. Compliance - end of pipe discharge monitoring. Compared with Namaleta Creek upstream site S4 n/a Raw Water Pit Monitor water quality of storages S5 W6 Discharge point from Western sump of current Fluvial Pit Compliance - end of pipe discharge monitoring. Compared with Namaleta Creek upstream site Limited direct relevance for bauxite mine, may assist in differentiating between potential impacts of kaolin mine and bauxite mining. Limited direct relevance for bauxite mine. Water quality will be used to assess if it is suitable for use in dust suppression, bauxite stockpile moisture content and washdowns Limited direct relevance for bauxite mine, may assist in differentiating between potential impacts of kaolin mine and bauxite mining. Easting (m) Northing (m) Yes No No Yes Yes

66 Page Monitoring Point Name per Current EA # S6 Namaleta Creek: Downstream Location Details Site Function Kaolin Mine Namaleta Creek: for an impacted site between 100 and 500 m downstream of kaolin mining area S7 n/a Namaleta Creek downstream of Pits 14 and 15, crossover between freshwater and estuarine systems S8 n/a Namaleta Creek immediately upstream of current crossing S9 n/a Namaleta Creek immediately downstream of current crossing Compliance Site. Compared with Namaleta Creek upstream site Site Function Bauxite Project Depth Logger Installed Compliance site downstream of Pits 12 and 14 during mining. Downstream of existing kaolin mine so provides baseline data for water quality potentially impacted by kaolin mine. Flows to be monitored. n/a Reference site prior to mining. Compliance site once mining commences. Water quality upstream of crossing and near Raw Water Pit. Access easy and safe from crossing. Water quality downstream of crossing and near Raw Water Pit. Access easy and safe from crossing. Compliance site downstream of Pits 12 and 14. Provides reasonable indication of baseline water quality in Namaleta Creek. Proposed for ongoing monitoring programme for quality and depth in case access restricted at other locations. Compliance site downstream of Pits 12 and 14 and crossing. Provides reasonable indication of baseline water quality in Namaleta Creek. Baseline depth data unimpacted by crossing. Proposed for ongoing monitoring programme in case access restricted at other locations. Flows to be monitored. Easting (m) Northing (m) No No Yes Yes

67 Page Monitoring Point Name per Current EA # Location Details Site Function Kaolin Mine Site Function Bauxite Project Depth Logger Installed S10 site prior to mining. Compliance n/a Lunette Swamp n/a Water quality and depth. Reference site once mining commences. S11 site prior to mining. Compliance n/a Bigfoot Swamp n/a Water quality and depth. Reference site once mining commences. S12 n/a Unnamed creek downstream Lunette Swamp S13 W2 Discharge point from existing Port sediment pond S14 n/a Discharge point - Port infrastructure area option 2 sediment pond. Exact location to be determined following detailed design. Nominal location of additional monitoring point in case two sediment ponds required at Port. S15 n/a Skardon River South Arm estuarine water downstream of Pit 3 and upstream of Port. n/a Downstream of Pits 3, 4, 5, 8, 9, 10, 11, 12, 13 Reference site prior to mining. Compliance site once mining commences. Compliance - release point discharge monitoring. Monitoring of runoff from Port infrastructure area n/a Compliance site - discharge monitoring of water quality runoff from Port infrastructure area / sediment pond. n/a Reference site prior to mining. Compliance site once mining commences. Easting (m) Northing (m) Yes Yes No No No No

68 # The location specified for ongoing monitoring may differ to slightly to the location in the EA in order to provide an improved monitoring location that considers accessibility and effectiveness in achieving the intended monitoring purpose. Page Monitoring Point Name per Current EA # Location Details Site Function Kaolin Mine S16 n/a Skardon River South Arm estuarine water downstream of all pits (Pits 1, 2, 3, 6) and upstream of Port. S17 n/a Skardon River South Arm estuarine water downstream of Port S18 n/a Skardon River supratidal wetland Site Function Bauxite Project Depth Logger Installed n/a Compliance site once mining commences. n/a Reference site prior to mining. Compliance site once mining commences. n/a Reference site prior to mining. Compliance site once mining commences. Easting (m) Northing (m) No No No

69 Surface Water Monitoring Frequency and Parameters The frequency of water quality monitoring at each location is variable and is affected by access problems due to necessary site safety precautions during rainfall and water levels. Details of proposed frequency of monitoring and monitoring parameters at each location are summarised in Table The current EA specifies monitoring frequency and parameters for the existing kaolin mine when in care and maintenance (i.e. its current status). These are included in the proposed monitoring frequency and parameters provided in Table 12-32, with modifications to reflect the monitoring proposed for the Project. The physico-chemical, nutrient and metals parameters that will be sampled are as per Table Water levels will also be monitored in fresh water environments of Namaleta Creek, Bigfoot Swamp and Lunette Swamp. Monitoring of water levels in estuarine environments will not provide information on potential changes in levels associated with bauxite mining as the water levels in these areas are dominated by tidal influences. The surface water samples will be analysed by a registered NATA accredited laboratory and sample collection and transportation will follow guidelines and protocols provided within the Monitoring and Sampling Manual 2009 (EHP, 2010) Surface Water Monitoring and Reporting Proposed water quality objectives for monitoring parameters for Namaleta Creek and wetlands are described in Table These are default water quality objectives and will be refined once sufficient baseline water quality data has been collected in accordance with the QWQG. If water quality characteristics from monitoring of compliance locations during mining exceed any of the water quality objectives specified in Table 12-2 then Gulf will compare the monitoring results in the downstream receiving waters to monitoring results from reference sites and: where the reference site results are not exceeded then no action will be taken, or if the result is greater than the reference site, complete an investigation into the potential for environmental harm and provide a written report to the administering authority in the next annual return outlining: details of the investigations carried out actions taken to prevent environmental harm. The following information will be recorded for all water monitoring: the date on which the sample was taken the time at which the sample was taken the monitoring point at which the sample was taken the results of all monitoring and details of any exceedances of the conditions of the EA. Page 12-65

70 S7 Quarterly n/a n/a Physico-chemical, nutrients, metals. S8 Quarterly. n/a n/a Physico-chemical, nutrients, metals. Page Table Surface Water Monitoring Frequency and Parameters Location Frequency Parameters Existing EA Amended for Project Final Parameters S1 Quarterly, when flowing. Continuous water depth logger. n/a n/a Quarterly for physico-chemical, nutrients, metals. Water levels. S2 (Namaleta Creek Upstream) Quarterly when flowing. Within 24 hours of discharge and thereafter weekly whilst discharging Turbidity, EC, ph Quarterly for physico-chemical, nutrients and metals Quarterly for physico-chemical, nutrients and metals. S3 (W1) Within 24 hours of discharge and thereafter weekly whilst discharging. Turbidity, EC, ph, oil and grease No amendments proposed Turbidity, EC, ph, oil and grease S4 (Raw Water pit) Quarterly, Continuous water depth logger EC, ph No amendments proposed EC, ph S5 (W6) Within 24 hours of discharge and thereafter weekly whilst discharging. Continuous water depth logger. Continuous turbidity logger in Fluvial Pit. Turbidity, EC, ph, oil and grease No amendments proposed Turbidity, EC, ph, oil and grease S6 (Namaleta Creek: Downstream) Quarterly when flowing. Within 24 hours of discharge and thereafter weekly whilst discharging Turbidity, EC, ph Quarterly for physico-chemical, nutrients and metals Quarterly for physico-chemical, nutrients and metals.

71 S12 Quarterly, when flowing n/a n/a Physico-chemical, nutrients, metals. S15 Quarterly n/a n/a Physico-chemical, nutrients, metals, hydrocarbons S16 Quarterly n/a n/a Physico-chemical, nutrients, metals, hydrocarbons S17 Quarterly n/a n/a Physico-chemical, nutrients, metals, hydrocarbons S18 Quarterly n/a n/a Physico-chemical, nutrients, metals Page Location Frequency Parameters Existing EA Amended for Project Final Parameters Continuous water depth logger Water levels. S9 Quarterly. Continuous water depth logger S10 Quarterly. Continuous water depth logger S11 Quarterly. Continuous water depth logger n/a n/a Physico-chemical, nutrients, metals. Water levels. n/a n/a Physico-chemical, nutrients, metals. Water levels. n/a n/a Physico-chemical, nutrients, metals. Water levels. S13 (W2) Within 24 hours of discharge and thereafter weekly whilst discharging. Turbidity, EC, ph, oil and grease Physico-chemical, nutrients, total petroleum hydrocarbons and metals Physico-chemical, nutrients, metals, total petroleum hydrocarbons, oil and grease S14 Within 24 hours of discharge and thereafter weekly whilst discharging. n/a n/a Physico-chemical, nutrients, metals, total petroleum hydrocarbons, oil and grease

72 Receiving Environment Monitoring Programme As described in Chapter 6, Project releases to receiving environments will be limited to sediment ponds at the Port infrastructure area. Never-the-less there is potential for mining related activities to result in increased erosion and sedimentation of receiving waters. The proposed monitoring programme outlined above will commence prior to construction and operations and continue throughout the mine life. This monitoring programme will inform the requirements of a Receiving Environment Monitoring Program (REMP) to monitor, identify and describe any adverse impacts to surface water environmental values, quality and levels due to bauxite mining activity. The REMP will be informed by: environmental values identified in Section 12.4 and Section 12.5 water quality objectives and indicators / parameters proposed for monitoring, including water depth and Creek flows (Section 12.5) location of monitoring sites, including reference sites and compliance / control sites (Table 12-31) timing and frequency of sampling (Table 12-32) Monitoring will involve a combination of (i) in situ measurements obtained using field instruments to monitor indicators such as turbidity, EC, DO and ph, and (ii) field sampling using manual grab sampling or auto-sampling with subsequent laboratory analysis. Monitoring will be undertaken in accordance with the Monitoring and Sampling Manual (EHP, 2009). The REMP will define quality assurance / quality control (QA/QC) procedures for all aspects of monitoring. Data analysis methods will be described in the REMP. Proposed ecological and biological monitoring of creeks and wetlands is described in Chapter 16. This monitoring is design to tie in with the surface water monitoring programme by undertaking monitoring at the same sites. Proposed monitoring in the estuarine / marine environment of the Skardon River is described in Chapter 17. The REMP will be developed and implemented to monitor, identify and describe any adverse impacts to surface water and groundwater environmental values, quality and flows due to the authorised mining activity. This will include monitoring the effects of the mine on the receiving environment periodically (under natural flow conditions). For the purposes of the REMP, the receiving environment is the waters of Namaleta Creek, Skardon River and wetlands within and surrounding the Project area downstream or down gradient of the authorised mining activity. The REMP will address the requirements of the REMP Guideline (EHP, 2015). A report outlining the findings of the REMP, including all monitoring results and interpretations will be prepared annually. The report will include an assessment of background reference water quality, the condition of downstream water quality compared against water quality objectives, and the suitability of current release limits to protect downstream environmental values Groundwater Monitoring The groundwater monitoring programme will include ongoing monitoring of the existing groundwater bores and additional bores. The bore number, location, purpose and summary of monitoring are described in Table The locations for the monitoring bore sites are shown in relation to the proposed bauxite mining pits and other bauxite mine infrastructure in Figure The proposed monitoring bore network comprises existing bores and new bores. Reference bores provide information on groundwater Page 12-68

73 upgradient of potential Project impacts. Compliance bores will be used for comparison to reference bores to assist in understanding potential Project impacts on groundwater. Prior to mining all bores will provide baseline groundwater data for the area. The groundwater levels for all bores will be recorded with a continuous, automatic logger to determine any shallow groundwater responses to rainfall events and to changes in local pumping regimes. Manual readings of standing water levels will be measured with a water level dipper quarterly so as to capture data during the wet and dry seasons and for calibration of the automated instrumentation within bores fitted with pressure transducers. It is intended that data will be downloaded from the pressure transducers on a six monthly basis at beginning and end of wet season, i.e. October November and April May. Manual water level measurements will be taken prior to downloading the data from the pressure transducer, such that the pressure transducer measurements can be calibrated. Analysis of groundwater samples will be recorded at the existing and proposed monitoring locations listed in Table at quarterly intervals. The samples will be tested at a NATA accredited laboratory for standard suites of analytes. Sample collection and transportation will follow guidelines and protocols provided within the Monitoring and Sampling Manual 2009 (EHP, 2010), with consideration given to sampling techniques for groundwater in a low yield bores. The testing will include the parameters described in Table Page 12-69

74 testing. testing. testing. Page Table Groundwater Monitoring Network Monitoring Point Location Details Location (GDA94 Zone 54) Easting Northing (m) (m) Reference Bores G1 Near Lunette Swamp and camp used for camp supply G9 Near haulroad, west of Pit 3 Bore Purpose Monitoring catchment; indicative of conditions near Pits 10, Supply water to camp from bore upgradient of impacts. Water quality historically suitable for (predominantly upgradient of Pit 3 area) and Conditions at the top of Lunette Swamp 11, 12 and 13. potable camp water Aquifer conditions at central mining pits upgradient of Bigfoot Swamp Water levels recorded with continuous logger; Sampling and laboratory testing; Continuous logging EC. Water levels recorded with continuous logger; Sampling and laboratory testing. G10 Near haulroad in line with Bigfoot Swamp G15 New bore upgradient of Lunette Swamp G16 New bore upgradient of Pits 14 and 15 C2 Near Bigfoot Swamp (predominantly upgradient of Pits 3, 2 and 6) Aquifer conditions at the northern end of mine and upgradient of Bigfoot Swamp Aquifer conditions upgradient of Lunette Swamp and all mine pits (Pits 5, 8, 9, 10) Aquifer conditions upgradient of Namaleta Creek and southern mine pits (Pits 14 and 15) Aquifer conditions up gradient from Bigfoot Swamp Water levels recorded with continuous logger; Sampling and laboratory Water levels recorded with continuous logger; Sampling and laboratory Water levels recorded with continuous logger; Sampling and laboratory Water levels recorded with continuous logger; Sampling and laboratory testing. Compliance Bores

75 G5 Port Area Downgradient of Port infrastructure area Water levels recorded with continuous logger; Sampling and laboratory testing. testing. testing. Water levels recorded with continuous logger; Sampling and laboratory testing. Water levels recorded with continuous logger; Sampling and laboratory testing. Page Monitoring Point Location Details Location (GDA94 Zone 54) Easting Northing (m) (m) C1 West of proposed mining Bore Purpose Monitoring Swamp but downgradient of Pits 4, 5, 8, 9 and Groundwater conditions upgradient of Lunette 10 Water levels recorded with continuous logger; Sampling and laboratory testing. G2 Former kaolin mine wet plant area (decommissioned) G6 West end of airstrip Aquifer condition upgradient of kaolin mine, within proposed mining area (Pit 12), downgradient Pits 11 and Aquifer condition at downgradient of Pits 11,12, 13 Water levels recorded with continuous logger; Sampling and laboratory Water levels recorded with continuous logger; Sampling and laboratory G3 North of Namaleta Creek Namaleta Creek and aquifer condition at downgradient of Pits 11,12, 13 Water levels recorded with continuous logger; Sampling and laboratory testing. G4 Namaleta South Conditions south of Namaleta Creek in palaeochannel aquifer (downgradient of Pits 14, 15) C3 Skardon River Between mining lease boundary and Skardon River South Arm. Aquifer conditions downgradient of central mining pits (Pit 3 area)

76 testing. testing. Water levels recorded with continuous logger; Sampling and laboratory testing. Water levels recorded with continuous logger; Sampling and laboratory testing; Continuous logging EC. Water levels recorded with continuous logger; Sampling and laboratory testing; Continuous logging EC. Page Monitoring Point Location Details Location (GDA94 Zone 54) Easting Northing (m) (m) G8 North of airstrip Groundwater conditions down gradient from Lunette Swamp and Pits 11, 12, 13) Bore Purpose Monitoring Water levels recorded with continuous logger; Sampling and laboratory G11 Skardon River Aquifer conditions at the northern end of mine down gradient of Pit 3. Water levels recorded with continuous logger; Sampling and laboratory G7 West of mining, Beach road Conditions at western end of mining area downgradient of Pits 11,12, 13) G13 Downstream Namaleta Creek G12 Downstream Namaleta Creek conditions downstream in Namaleta Creek to interface resulting from water use from kaolin Existing bore, to be monitored for groundwater monitor potential migration of saltwater pit areas. Downgradient of Pit conditions downstream in Namaleta Creek to interface resulting from water use from kaolin Existing bore, to be monitored for groundwater monitor potential migration of saltwater pit areas. Downgradient of Pit 12

77 Page Monitoring Point G14 Downstream Namaleta Creek Location Details Location (GDA94 Zone 54) Easting Northing (m) (m) G17 Near proposed water supply production bores at the Port area G18 Near proposed Namaleta borefield, south of Namaleta Creek Bore Purpose Monitoring conditions downstream in Namaleta Creek to interface resulting from water use from kaolin Existing bore, to be monitored for groundwater monitor potential migration of saltwater pit areas. Downgradient of Pit Monitor groundwater levels near proposed water supply bores at Port area Monitor groundwater levels near proposed water supply bores in Namaleta Borefield Water levels recorded with continuous logger; Sampling and laboratory testing; Continuous logging EC. Water levels recorded with continuous logger; Sampling and laboratory testing. Water levels recorded with continuous logger; Sampling and laboratory testing.

78 Queensland CAIRNS TOWNSVILLE ± ROCKHAMPTON BRISBANE ( SKARDON RIVER ML ( ML G5 1:30,000 G17 C G14 G13 G12 G3 G2 G10 G NAMALETA CREEK G4 G9 C3 G :30,000 G8 C1 G G7 ML 6025 G6 G1 NAMALETA CREEK G Kilometers Legend Mining Lease Boundaries ( Port of Skardon River Watercourses Monitoring Bores Existing Proposed Figure Date: 7/10/2015 Existing and Proposed Monitoring Bores Author: malcolm.nunn Map Scale: 1:80,000 Gulf Alumina Limited Revision: R1 Coordinate System: GDA 1994 MGA Zone 54 G:\CLIENTS\E-TO-M\Gulf Alumina\GIS\Maps\EIS\Ch12_WaterQuality\FIG_12_17_Existing_Prop_GWMPs_ mxd No warranty is given in relation to the data (including accuracy, reliability, completeness or suitability) and accept no liability (including without limitation, liability in negligence) for any loss, damage or costs (including consequential damage) relating to any use of or reliance upon the data. Data must not be used for direct marketing or be used in breach of privacy laws. Tenures Geos Mining (2015). State Boundaries and Towns Geoscience Australia (2006). Watercourses Geoscience Australia. Imagery ESRI (2015).

79 Saline Water Ingress Mining of the pits and water supply from the Namaleta borefield, is predicted to result in potential drawdowns of 0.4 m at reaches of the Creek immediately adjacent to the former kaolin mine (refer to Chapter 13 for groundwater modelling results). A reduction in local baseflow has the potential to change normal tidal behaviour of Namaleta Creek that could result in increased seasonal saline excursion upstream. Monitoring will be in place to detect saline water incursion (bores G4, G12, G13 and G14 in Table 12-33) and inform operational decisions such as borefield pumping. In addition the exact location of future supply bores (refer Chapter 6) in the area will be chosen to avoid impacting baseflow and inducing potential intrusion of saline water Targeted Monitoring Bores Groundwater monitoring bores will be installed upgradient and downgradient of the following Project activities with the potential to contaminate groundwater: landfill near the Port bioremediation pad currently located near the former kaolin mine wet plant area but proposed for relocation to the landfill area at the Port once prior to mining in this area (Year 2 or 3) hydrocarbon storage at the port effluent irrigation area. The monitoring programme for these bores is described in Chapter 8 (effluent irrigation area) and Chapter 11 (landfill, bio-remediation pad and hydrocarbon storage). Bores will also become operational at commencement of the Project operations and will include monitoring of specific parameters, which will include: faecal coliforms and ammonia at sewerage irrigation site and bio remediation area total petroleum hydrocarbons at hydrocarbon storage area near the Port ammonia, chemical oxygen demand, EC and ph at landfill site Groundwater Monitoring and Reporting Groundwater levels will be recorded up gradient and down gradient of mining activities in order to aid is identifying potential Project impacts and natural variations in groundwater levels of shallow aquifers of the Project area. Changes in groundwater levels in compliance bores will be compared to changes in reference bores and an investigation undertaken if changes are not within natural variations. Groundwater quality and levels will be monitored at the bores, and at the frequency, listed in Table for the water quality characteristics described in Table If groundwater quality characteristics from monitoring of compliance bore locations during mining exceed any of the groundwater quality objectives specified in Table 12-2 (groundwater water quality objectives) then the environmental authority holder will compare the monitoring results in the compliance bores to monitoring results from reference bores and: an investigation will be completed in accordance with the provisions of the AWQG where the reference bore results are not exceeded then no action will be taken, or if the result is greater than the reference bore, complete an investigation into the potential for environmental harm and provide a written report to the administering authority in the next annual return outlining: details of the investigations carried out Page 12-75

80 actions taken to prevent environmental harm. The following information will be recorded for all groundwater monitoring: the date on which the sample was taken the time at which the sample was taken the monitoring point at which the sample was taken the results of all monitoring and details of any exceedances of the conditions of the EA Bore Construction Bore construction, maintenance and decommissioning will be carried out in compliance with the guidelines of Minimum Bore Construction Requirements for Water Bores in Australia (Edition 3), ARMCANZ (2012), to prevent or minimise impacts to the environment and further to ensure the integrity of the bores to obtain accurate monitoring data for the Project Risk Assessment A risk assessment assessing the likelihood and significance of impacts to surface water and groundwater quality from the Project is provided in Table The risk assessment considers mitigated risk; that is, the impact from the Project with the implementation of management measures. The risks to water quality are low to medium. Table Environmental Value Surface water quality (watercourses and wetlands) Groundwater quality Risk Assessment and Management Measures for Impacts to Water Quality Impacts / Emissions / Releases Increased sedimentation. Refer Section Hydrocarbon or chemical contamination. Refer Section Contamination from waste or bio-remediation pad. Refer Section Hydrocarbon or chemical contamination. Refer Section Contamination from waste or bio-remediation pad. Refer Section Proposed Management Practices Refer Section 12.9 and Section Refer Section 12.9 and Section Refer Section 12.9 and Section Refer Section 12.9 and Section Refer Section 12.9 and Section Likelihood Consequence (Magnitude) Risk Rating Likely Minor Medium Possible Minor Medium Unlikely Minor Low Possible Minor Medium Unlikely Minor Low Page 12-76

81 12.12 Cumulative Impacts Skardon River Bauxite Project Cumulative impacts are considered for all known or reasonably foreseeable projects with the potential for spatial and temporal impacts in combination with the Skardon River Bauxite Project. The projects in the Cape York region which potentially meet these criteria are: Metro Mining Ltd s (formerly Cape Alumina Ltd s) Bauxite Hills project Rio Tinto s existing bauxite mining operation near Weipa Rio Tinto s proposed South of Embley Project Rio Tinto s existing and proposed projects are not considered to have a cumulative impact on water quality with the Skardon River Bauxite Project as the projects are approximately 90 km apart, do not share the same catchments or hydrology and do not operate in the same near shore waters. The only project considered to have a cumulative impact with the Skardon River Bauxite Project is the Bauxite Hills project. Based on publically available information, the Bauxite Hills project would be for an integrated bauxite mine adjacent (east and west) to the Project and port located to the immediate south of the Skardon River. The pre-feasibility information for the Bauxite Hills project describes a 2 Mtpa bauxite mine with over 21 year mine life and a 61.5 Mt indicated and inferred resource. The Bauxite Hills project includes a new barge loading facility on the Skardon River, barging of bauxite to an offshore transhipment area, workers camp and haul road transport corridor. A conceptual mine plan for the Bauxite Hills project is provided in Figure 12-18, which shows mining to the east and west of the Skardon River Bauxite Project. Figure Conceptual Mine Plan Bauxite Hills Project Page 12-77