Biodiversity Impact Assessment
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March 2020 19121900-328397-9 APPENDIX H Biodiversity Impact Assessment REPORT Specialist Assessment for the Proposed Surface Pipeline and Associated Infrastructure - Biodiversity Impact Assessment AngloGold Ashanti (Pty) Limited South African Operations Submitted to: Anglo Gold Ashanti (Pty) Limited South African Operations Mr J van Wyk Carletonville - Fochville Road R500 Carletonville Gauteng 2501 Submitted by: Golder Associates Africa (Pty) Ltd. Building 1, Maxwell Office Park, Magwa Crescent West, Waterfall City, Midrand, 1685, South Africa P.O. Box 6001, Halfway House, 1685 +27 11 254 4800 19121900-327695-6 February 2020 February 2020 19121900-327695-6 Distribution List 1 eCopy to Anglo Gold Ashanti (Pty) Limited South African Operations 1 eCopy to [email protected] i February 2020 19121900-327695-6 Executive Summary Project overview The AGA operations in the West Wits mining lease areas are at risk of flooding due to ingress of fissure water from surrounding mining operations. Approximately 25 Mℓ/day of fissure water flows into the underground workings of the defunct Blyvooruitzicht Mine, which spans a strike of 6 km along the boundary with AGA. If dewatering at the Old Blyvooruitzicht Shafts (#4, #5 & 6#) shafts were to cease, uncontrolled fissure water would report to the AGA operations, which would pose both a flood and safety risk of AGA personnel and the mining operations. This report provides a professional opinion regarding the anticipated terrestrial, wetland and aquatic impacts from this proposed project. Location The proposed water pipeline and associated infrastructure is located approximately 80 km west of Johannesburg. It originates at CWC 4#, approximately 3.3 km south east of Carletonville and ends at the North Boundary Dam (NBD) approximately 6 km south-south-west of Carletonville in Blyvooruitzicht, Merafong City Local Municipality, West Rand District Municipality in the Gauteng Province of South Africa. Baseline summary Note: The proposed pipeline corridor is located in an area dominated by mining and associated activities. Due to significant security risks concerning the presence and activities of armed illegal miners, the ability to collect data in-field was highly constrained. The baseline biodiversity description presented in the report is thus based on available ecological literature, supported by high-level field observations and photographs taken during a drive-over of the pipeline corridor in an armoured vehicle. The landscape is highly modified and fragmented. Habitats recorded along the proposed pipeline corridor include grassland and woodland. Grassland habitats include dry, terrestrial grassland, and moist grassland (wetlands). These display variable signs of disturbance. Woodland habitats consist mostly of stands of alien invasive tree species. Common species include listed alien trees such as Eucalyptus and the highly invasive Acacia mearnsii and Acacia dealbata. Indigenous trees are far less abundant and generally occur as small stands or scattered individual trees, with Vachellia karroo and Rhus pyroides occurring fairly commonly. A review of faunal data indicates that although the area would historically have had a rich faunal assemblage, various past and current anthropogenic activities have caused significant habitat disturbance and fragmentation across the landscape, which coupled with hunting, have likely resulted in reduced faunal abundance and diversity in the current context. A desktop delineation of suspected wetland areas was undertaken by identifying and mapping wetness signatures (areas of flooding, wet soils, hydrophytic vegetation) on aerial imagery using Google Earth Pro. Field verification of the preliminarily identified wetland boundaries was limited due to the afore-mentioned security constraints. Six wetlands were identified within 500 m of the proposed pipeline; of these, only one will be impacted by the pipeline as currently proposed. The pipeline crossing is situated predominantly within a disturbed wetland unit, characterised by the presence of erosional features, vehicle tracks and artificial drainage channels. From an aquatic perspective, the diatom assemblages identified were generally comprised of species characteristic of fresh-brackish, circumneutral to alkaline waters and eutrophic to hyper-eutrophic conditions. The pollution levels indicated that both sites showed some form of pollution. ii February 2020 19121900-327695-6 According to the spatial distribution, the upstream site appeared to be impacted to a greater extent compared to the downstream site reflecting Poor conditions. Whereas, the ecological water quality at the downstream site appeared to show a slight recovery and improvement in comparison to the upstream site reflecting lower levels of organic pollution and Moderate conditions. Conversely as per the toxicity results, the WET results indicated higher toxicity levels at the downstream site (Class IV) compared to the upstream site (Class II). Although the downstream site had a lower conductivity, it had a much higher expressed toxicity across all the trophic level tests. Impact assessment summary The following potential impacts on biodiversity were identified and rated for before and after mitigation: Impact Before Mitigation After Mitigation Construction Phase Loss and disturbance of natural habitat. Moderate Low Loss of plant species of conservation concern. Low Low Soil erosion and sedimentation of the unnamed tributary to the Moderate Low Mooirivierloop Alien invasive species establishment. Moderate Low Interruption of wetland hydrology Low Low Deterioration in wetland water quality Moderate Low Operational Phase Establishment of alien invasive species Moderate Low Leaks/spills of contaminated water into the unnamed tributary to Moderate Low the Mooirivierloop Changed flows in wetland due to leaks or pipe failure Low Low Decommissioning Phase Establishment of alien invasive species Low Low Soil erosion and sedimentation of unnamed tributary to the Low Low Mooirivierloop Recommended mitigation and management measures should be included in the overall Environmental Management Plan (EMP) for this project. Provided that the recommended mitigation and management measures are adhered to throughout all phases of the lifetime of the pipeline (construction, operation and decommissioning), the residual impacts can be reduced to low significance. Two cumulative impacts have been identified; alien invasive plant species and the loss and disturbance of habitat. Overall, these can also be maintained at a low significance with proactive and ongoing management iii February 2020 19121900-327695-6 Assumptions, limitations & exclusions As mentioned above, the proposed pipeline corridor is located in an area dominated by mining and associated activities. Due to significant security risks concerning the presence and activities of armed illegal miners the ability to collect data in-field was highly constrained. The baseline biodiversity presented in the report is thus based on available ecological literature, supported by high-level field observations and photographs recorded during a drive-over of the pipeline corridor in an armoured vehicle. No in-field surveys were conducted for the aquatic and wetland components. However, samples were obtained during the terrestrial survey which supplemented the aquatic component. iv February 2020 19121900-327695-6 Acronym List Acronyms AGA AngloGold Ashanti BDI Biological Diatom Index BLV Blyvooruitzicht CARA Conservation of Agricultural Resources Act DWS Department of Water and Sanitation EIS Ecological Importance and Sensitivity HGM Hydro-geomorphic LoM Life of Mine IUCN International Union for Conservation of Nature NBD North Boundary Dam NEMBA National Environmental Management: Biodiversity Act PES Present Ecological Status %PTV Percentage of Pollution Tolerant Values SPI Specific Pollution Sensitivity Index TUa Toxicity units WET Whole Effluent Toxicity v February 2020 19121900-327695-6 Table of Contents 1.0 INTRODUCTION ......................................................................................................................................... 1 2.0 PROJECT BACKGROUND ........................................................................................................................ 1 2.1 Location of the proposed project ....................................................................................................... 1 3.0 STUDY APPROACH AND METHODOLOGY ............................................................................................ 3 3.1 Limitations and Constraints ............................................................................................................... 3 3.2 Terrestrial Ecology ............................................................................................................................ 3 3.2.1 Literature Review .......................................................................................................................... 3 3.2.2 Field Programme ........................................................................................................................... 4 3.2.3 Screening of Species of Concern ................................................................................................. 4 3.2.3.1 Species of Concern ....................................................................................................................... 4 3.2.3.2 Habitat Suitability Assessment .....................................................................................................