Undermining Surface Water Resources at Goedehoop South and North Collieries Addendum 1

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1 Undermining Surface Water Resources at Goedehoop South and North Collieries Addendum 1 Report Prepared for Anglo American Thermal Coal Report Number Addendum 1) Report Prepared by May 2016

2 SRK Consulting: Addendum 1 Undermining Surface Water Resources at GHS & GHN Page i Undermining Surface Water Resources at Goedehoop South and North Collieries Addendum 1 Anglo American Thermal Coal SRK Consulting South Africa) Pty Ltd Section A Second Floor Norfolk House 54 Norfolk Terrace Westville 3630 South Africa Sagadevan Raven) Kisten skisten@srk.co.za website: Tel: +27 0) Fax: +27 0) SRK Project Number Addendum 1) May 2016 Compiled by: IS Cameron-Clarke Consultant Reviewed by: I Mahomed Pr.Sci.Nat. Associate Partner imahomed@srk.co.za Authors: I Mahomed; IS Cameron-Clarke CAME\maho _Undermining Surface Water Resources at GHS GHN Addendum 1).docx May 2016

3 SRK Consulting: Addendum 1 Undermining Surface Water Resources at GHS & GHN Page ii Table of Contents Disclaimer... iii 1 Introduction and Terms of Reference Objective Summaries of SRK, SM and DWE studies SRK SM DWE Revised Impact Assessment... 6 List of Tables Table A-1: Goedehoop North - Assessment of the Potential for Further Adverse Impacts on surface water bodies due to future undermining including Saxum and DWE evaluations)... 9 Table A-2: Goedehoop South - Assessment of the Potential for Further Adverse Impacts on surface water bodies due to future undermining including Saxum and DWE evaluations) List of Figures Figure A-1: Goedehoop South: Impact Assessment Of Undermining Of Surface Water Resources... 7 Figure A-2: Goedehoop North: Impact Assessment Of Undermining Of Surface Water Resources... 8 CAME\maho _Undermining Surface Water Resources at GHS GHN Addendum 1).docx May 2016

4 SRK Consulting: Addendum 1 Undermining Surface Water Resources at GHS & GHN Page iii Disclaimer The opinions expressed in this Report have been based on the information supplied to SRK Consulting South Africa) Pty) Ltd SRK) by Anglo American Thermal Coal. The opinions in this Report are provided in response to a specific request from Anglo American Thermal Coal to do so. SRK has exercised all due care in reviewing the supplied information. Whilst SRK has compared key supplied data with expected values, the accuracy of the results and conclusions from the review are entirely reliant on the accuracy and completeness of the supplied data. SRK does not accept responsibility for any errors or omissions in the supplied information and does not accept any consequential liability arising from commercial decisions or actions resulting from them. Opinions presented in this report apply to the site conditions and features as they existed at the time of SRK s investigations, and those reasonably foreseeable. These opinions do not necessarily apply to conditions and features that may arise after the date of this Report, about which SRK had no prior knowledge nor had the opportunity to evaluate. CAME\maho _Undermining Surface Water Resources at GHS GHN Addendum 1).docx May 2016

5 SRK Consulting: Hydrogeological Study Undermining Surface Water Resources at GHS & GHN Page 4 1 Introduction and Terms of Reference During 2014, Anglo American Thermal Coal Division AATCD) commissioned SRK Consulting SRK) to undertake an assessment of the potential impacts of the underground mining operations on surface water resources at the Goedehoop North and South mines. The findings of that study were presented in SRK Report dated October Only selected Priority Sites, identified by AATCD at that time, were included in the assessment. Subsequently, further specialist studies addressing a Rock Engineering Risk Assessment for Undermining Waterbodies, and an Ecological Assessment of Wetlands associated with the Goedehoop Colliery, and were carried out by Saxum Mining SM) Report AAC December 2015) and Digby Wells Environmental Report ANG3323 May 2016) respectively. AATCD has requested SRK to incorporate the findings of those studies into their 2014 impact assessment, ensuring consistency between the various studies. It is understood that both Saxum Mining SM) and Digby Wells Environmental DWE) are also revising their reports. The mining areas used for each study were different. On instruction from AATCD, the mining areas used in the SM study have been adopted here see Figures A-1 and A-2). In order to avoid unnecessary rewriting of background information contained in SRK Report of October 2014 the updated assessment is presented as an addendum Addendum 1) to that report. Reference to the SRK Report of October 2014, as well as the final SM and DWE reports, should therefore be made as required. 2 Objective The objective is to update, as appropriate, the impact assessment presented in SRK Report of October 2014, taking cognisance of the findings presented by SM and DWE. 3 Summaries of SRK, SM and DWE studies 3.1 SRK 2014 For the original SRK study 2014) study potential impacts on surface water bodies resulting from undermining were identified as: Reduced stream flow due to topographic changes resulting from surface settlement causing changes to runoff drainage patterns; Reduced stream flow due to lowering of the groundwater table and a consequential reduction of base flow; Stream capture due to surface settlement and/or collapse; Dewatering of existing pans and dams caused by damage to the integrity of underlying geological formations; Development of new areas of surface saturation pans) due to surface settlement; and Future decanting of acid water from flooded underground workings if a positive water balance develops from an increased ingress of surface water via mine openings. All these impacts relate to: changes to the hydraulic integrity of the geological formations overlying mining areas; possible changes to topography, water flow directions and flow rates. CAME\maho _Undermining Surface Water Resources at GHS GHN Addendum 1).docx May 2016

6 SRK Consulting: Hydrogeological Study Undermining Surface Water Resources at GHS & GHN Page 5 Pertinent criteria considered likely to influence the degree to which these impacts could occur were identified as: The depth and areal extent of mining; The mining designs and method pillar design criteria); Extent of previous multi-seam mining; The locations of surface water bodies relative to the underground mining areas; The geological formations overlying the underground mining areas; The presence of dolerite dykes and sills and associated fracture zones; The hydraulic connectivity of aquifers; Hydraulic connectivity between surface water bodies and underlying aquifers; and Rainfall and evaporation. Extensive previous mining has taken place at Goedehoop refer to SRK Report ; Section 8) and has already impacted on both the local ground water and surface water environments. Available data indicated that surface settlements have been recorded in several areas, with mining depths varying from as little as 12 m up to 80 m below surface level. The extent to which these may have affected surface water features was not recorded. For the 2014 SRK study mining depths at the Priority Sites identified by AATCD were generally less than 50m, and, for the purpose of that study, it was assumed that: The mine designs and mining method selection for future mining have taken cognisance of the mining depths; Wherever previous mining has been recorded on other seams particularly No. 5 Seam) this has been considered as potentially increasing hydraulic connection; Wherever previous mining of the deeper No.2 seam has taken place, fracturing of the roof rocks above could have occurred but not necessarily sufficient to have adverse impacts on surface water features. 3.2 SM 2015 The SM study Report AAC December 2015) has provided a detailed rock engineering evaluation of the likelihood of failure in existing and planned underground workings that could cause surface subsidence and consequential adverse impacts on surface water bodies at seventeen 17) areas at Goedehoop North and twenty-four 24) areas at Goedehoop South respectively. The study has been based on the rock engineering guidelines and factors used for the design of mining layouts and panels at Goedehoop. Areas of, Medium and High risk of adverse impact on surface water bodies have been identified. The ecological importance and current state of the surface water bodies were not included see DWE report summary below). 3.3 DWE 2016 The DWE study has included a description of all wetland bodies in the Goedehoop areas, and provides an evaluation of the causes and effects of undermining on wetland areas. Evaluations of the Present Ecological State PES) and Ecological Importance and Sensitivity EIS) of the wetlands identified were included. One hundred meter 100m) buffer zones, were demarcated around the wetlands identified. Impact assessments of three areas of planned future mining were also provided It was noted that the wetlands within the study area have undergone extensive transformation from their natural state and no longer represent natural systems, the majority being largely modified Class D) and in some cases, the change in ecosystem processes and loss of natural habitat and biota was great Class E). Some wetlands, such as a portion of the Olifants River, have been CAME\maho _Undermining Surface Water Resources at GHS GHN Addendum 1).docx May 2016

7 SRK Consulting: Hydrogeological Study Undermining Surface Water Resources at GHS & GHN Page 6 moderately modified Class C). The EIS evaluations were used to assess the system s ability to resist disturbance and its capability to recover from disturbance once it has occurred. The majority of wetlands were assigned an EIS class of D, indicating that they held marginal to low ecological sensitivity. 4 Revised Impact Assessment The findings and conclusions presented in both the SM and DWE reports have been incorporated directly into the updated impact assessment. Reference to the original documents should be made as considered necessary. On the basis that the mining designs and methods for future mining will be the determining criteria that will influence the integrity of the overlying roof strata and the potential for surface settlements with consequential further adverse impacts on surface water bodies, it has been assumed that the SM impact ratings are the governing ratings for each area of planned future mining, unless other factors i.e. previous mining induced impacts; modified ecosystems; low ecological importance and sensitivity) indicate that existing adverse impacts have already occurred. The proposed revised Risk Ratings Tables A-1 and A-2) are based on the SM and DWE criteria as well as a subjective evaluation of types of surface water features, depth to the water table, and history of previous impacts. In all cases, particularly those of medium and high adverse impact risk, mitigation measures in the form of no mining i.e. applying 100m buffer zones) or mine designs to higher factors of safety could be considered. CAME\maho _Undermining Surface Water Resources at GHS GHN Addendum 1).docx May 2016

8 P6 South East Shaft R19 Shaft 1566 P R11 R Blinkpan Village Ko r in 1573 Block 11 Shaft Block Shaft Hope Village Hope Silo R Hope 4 Seam P18 Olifants R5 Legend R3 R9 R '0"S Seam 4 Seam 5 Mini Pits Site Boundary Mined out areas Seam 5 Mined out Areas Data Source: Seam 4 Mined Out Seam 2 Mined Out 29 15'0"E r ui t in spr u it 26 10'0"S Inland water bodies Seam f ont e uit Non-Perennial Rivers Seam 1 g sp L eeu l sp r Perennial Rivers Mine Plan n ko o Rivers 2 Seam Decant Points R7 Stee 4 Seam Decant Points R2 Approximate M ine Decant Points after Hodgson, 2011) R8 Central Shaft R6 26 5'0"S R14 Vandyksdrift Village Block 6 P4 R12 P Woes-A lle Block 9 Block e nspruit Shaft Johannesburg Shaft 26 5'0"S R20 Block 2 Sprinbok Village Site ID Shaft S p o o ks R18 Block P '0"E Goedehoop 1542 South 29 25'0"E p ruit 29 20'0"E 29 15'0"E '0"E 29 25'0"E '0"E GOEDEHOOP COLLIERY HYDROGEOLOGICAL STUDIES- UNDERMINING SURFACE WATER RESOURCES GOEDEHOOP SOUTH :IMPACT ASSESSMENT OF UNDERMINING OF SURFACE WATER RESOURCES Path: G:\445324_ANGLO_HYDRO_STUDY\8GIS\GISPROJ\MXD\2016\445324_FA1_Goedehoop_GHS_Priority_Areas_A3L_C_ mxd Kilometers Scale: 1: Projection: Datum: TM Cape Central Meridian/Zone: Lo29 Date: Compiled by: 19/05/2016 ALLK Project No: Fig No: A-1 Revision: B Date:

9 29 35'0"E Goedehoop North t rui Va a l ba nk sp rui t Co p ers etz 25 55'0"S 29 30'0"E 25 55'0"S 29 25'0"E J oo Simunye Shaft Sp I e nspruit Brown Shaft ks A B Block 10 5 Seam M Legend C Mine Plan Approximate Mine Decant Points after Hodgson, 2011) 4 Seam Decant Points 2 Seam Decant Points Seam 1 Seam 2 F Seam 4 Site ID E South EastMined Shaft Non-Perennial Rivers Inland water bodies Block 2 K D South Shaft Q Mini Pits Perennial Rivers Seam 5 Rivers 26 0'0"S t P O N 26 0'0"S Woes-A lle G ui pr H Site Boundary out areas Seam 5 Mined out Areas Data Source: Seam 4 Mined Out Seam 2 Mined Out '0"E '0"E GOEDEHOOP COLLIERY HYDROGEOLOGICAL STUDIES- UNDERMINING SURFACE WATER RESOURCES GOEDEHOOP NORTH: IMPACT ASSESSMENT OF UNDERMINING OF SURFACE WATER RESOURCES Path: G:\445324_ANGLO_HYDRO_STUDY\8GIS\GISPROJ\MXD\2016\445324_FA2_Goedehoop_GHN_Priority_Areas_A3L_C_ mxd 1 2 Kilometers 29 35'0"E Scale: 1: Projection: Datum: TM Cape Central Meridian/Zone: Lo29 Date: Compiled by: 19/05/2016 ALLK Project No: Fig No: A-2 Revision: B Date:

10 Table A-1: Goedehoop North - Assessment of the Potential for Further Adverse Impacts on surface water bodies due to future undermining including Saxum and DWE evaluations) Mining Area Planned Mining Seam Mining previously practised Approximate minimum depth of Mining m) Presence of Geological Structures dykes, faults and sills) SAXUM Risk Rating Type of water feature to be undermined DWE) Present Ecological State DWE) Environmental Importance & Sensitivity Category DWE) Depth to water table 2013 m) Regional groundwater level change m) 2006 to 2013 Other Influencing Factors Proposed Risk Ratings for Further adverse impact on surface water features A None 2 Seam 4 Seam NA Dyke. No. 4 Seam). Subsidence recorded in close proximity. 2) Unchannelled valley bottom Non-perennial stream D D 10 10m rise Likely base flow component to nonperennial stream. B 4 Seam ) 4 and 2 Seams <50 Subsidence recorded in close proximity. Medium12) C None 2 Seam NA No 2) D E F 4 Seam ) 5 Seam 4 Seam ) 2 Seam Some 5 Seam Close Proximity) <50 Dyke. No. 2 Seam). Subsidence recorded in close proximity. High 54) 2 Seam >50 No 4) 4 Seam ) 2 Seam and 5 Seam >50 Dyke and possibly sill. No. 2 Seam & 4 Seam) 9) Channelled and bottom /Hillslope seep Non-perennial Stream Hillslope seep to Bankspruit, Farm Dams 1 to 4 bottom bottom D D 5 5m rise Likely base flow component forming hillslope seep. D D 5 10m rise Non-perennial stream D D 16 0 Mining depth 20m and evidence of existing surface subsidence. D D 20 0 Mining depth >50m. D D 18 0 No identified surface water body Mining depth >50m. Medium High. G 1 Seam 2016) 4 Seam 2017) 4 and 2 Seams <50 No Medium 12) Hillslope seep D D 12 < 5 Mining depth <50m. Shallow water table Medium H 2 Seam 2016) 4 Seam 2016) 2 and 5 Seam >50 Dyke. No. 4 Seam) Medium 36) Hillslope seep D D 20 0 Mining depth >50m. I 1 Seam 2016) 4 Seam 2016) 4 and possibly 2 Seam) <50 No 6) bottom/farm Dam D D 16 < 5 The dam is isolated from any river or tributary and relies on surface runoff alone for recharge. J 1 Seam 2016) 4 Seam <50 No 6) bottom/farm Dam D D 16 < 5 The dam is isolated from any river or tributary and relies on surface runoff alone for recharge. None None NA Pan North) D D 22 Ogies Dyke. No. 2 K 2) 4 Seam Seam) 2 Seam <50 Pan South) D D ) L M 4 Seam ) 4 Seam ) 2 Seam <50 5 and 2 Seams <50 Dyke and possibly sill. No. 2 Seam) Dyke and possibly sill. No. 2 Seam. No. 4 Seam structure slightly north) Medium 36) Perennial Stream D D 20 0 High 54) Hillslope seep Non-perennial stream D D 20 < 5 0 Regional dyke and relatively shallow mining. Perennial Stream Potential connection along dykes. Mining <50m. Hillslope seep to non-perennial stream Mining >50m. High Medium N None 5 and 2 Seams NA Unknown Medium 36) bottom D D 38m Less than 1m drop None Medium O None 2, 4 and 5 Seam NA Unknown High 54) Hillslope seep D D 70 Approximately 5m drop Existing surface subsidence Medium P None 2 Seam NA Unknown Medium 36) None D D 32m Approximately 4m drop No identified surface water feature Q 5 Seam Construction) 4 Seam ) 2 Seam >50 Sill. No. 2 Seam) 2) Hillslope seep/farm Dam D D 53m 0 Note 1: Present Ecological State - Catergory D : Largely modified with a large change in ecosystem processes and loss of natural habitat and biota Note 2: Ecological Importance and Sensistivity - Class D : /marginal. Not ecologically important and sensitive at any scale. Insignificant in moderating the quantity and quality of major rivers

11 Table A-2: Goedehoop South - Assessment of the Potential for Further Adverse Impacts on surface water bodies due to future undermining including Saxum and DWE evaluations) Site Number Planned Mining Seam Mining previously practised Depth of Planned Mining m) Presence of geological structures dykes, faults and sills) SAXUM Risk Rating for undermining surface water bodies Type of water feature to be undermined Present Ecological State DWE) Environmental Importance & Sensitivity Category DWE) Depth to water table 2013 m) Regional Groundwater level change 2006 to 2013 Other Influencing Factors Proposed Risk Ratings for Further adverse impact on surface water features P1 4 Seam 2015) 4 Seam ) 5 Seam <50 Yes High 54) Pan D D Approximately 32m Dropped by approximately 22m. Ecologically unimportant Medium P3 None None NA No 2) Pan D D Approximately 27m Dropped by approximately 26m Ecologically unimportant P4 4 Seam 2017) 2 Seam 4 Seam 2015) <50 Dyke. Medium 18) Pan D D 29 Dropped by 25m. Groundwater level affected by regional mining impact. Pan dry in June 2014 Extensive regional dewatering already. P6 None 2 Seam NA No Medium 36) Pan D D 24 Dropped by 20m. Groundwater level affected by regional mining impact. Extensive regional dewatering already. P8 None 4 Seam NA Dyke. 3) Hillslope seep D D 24 Dropped by 20m. Pan dry in June 2014 Extensive regional dewatering. Potential for hydraulic connection along dyke. P18 4 Seam ) 2 Seam <50 No 1) Pan D D 16 Dropped by 10m. Pan contained water in June 2014 Shallow mining depth but no structures. R 1 4 Seam ; ) 2 Seam <50 No Medium 36) Hillslope seep/ Perennial Stream D D 16 Dropped by approximately 12m. The 2006 groundwater surface occurred within 3-5 m below the surface water body. Previous mining of 5 Seam could contribute to hydraulic connection. Perennial stream Medium R 2 4 Seam ) 2 Seam >50 Fault Medium 36) bottom/seasonal Stream D D 26 Dropped by approximately 20m. Regional dewatering. Previous mining of 5 Seam likely to contribute to hydraulic connection. Regional fault structure also potential flow path. Medium R 3 4 Seam ) 2 Seam > 50 No Medium 18) Channelled valley bottom D D 15m Dropped by approximately 12m Regional dewatering. Previous mining of 2 Seam. Medium R 4 None 2 Seam NA Unknown 3) Channelled valley bottom/ Perennial Stream D D 24m Dropped by approximately 25m Perennial Stream R 5 None 2 and 5 Seams NA Unknown 1) Hillslope seep D D 24m Dropped by approximately 25m Regionally dewatered. No additional mining R 6 None 2 and 5 Seams NA Unknown 1) Hillslope seep D D 23m Dropped by approximately 26m Regionally dewatered. No additional mining R 7 None 2 and 5 Seams NA Unknown Medium 27) Hillslope seep/seasonal stream D D 22m Dropped by approximately 23m Existing surface subsidence Medium

SRK Consulting: 445324 Hydrogeological Study Undermining Surface Water Resources at GHS & GHN Page 11 SRK Report Distribution Record Report No. 445324: Addendum 1 Copy No.

12 SRK Consulting: Hydrogeological Study Undermining Surface Water Resources at GHS & GHN Page 11 SRK Report Distribution Record Report No : Addendum 1 Copy No. Name/Title Company Copy Date Authorised by Kgaowelo Moshokwa Anglo American Thermal Coal 1 May 2016 I Mahomed Library SRK Consulting 2 May 2016 I Mahomed File SRK Consulting 3 May 2016 I Mahomed Approval Signature: This report is protected by copyright vested in SRK SA) Pty) Ltd. It may not be reproduced or transmitted in any form or by any means whatsoever to any person without the written permission of the copyright holder, SRK. CAME\maho _Undermining Surface Water Resources at GHS GHN Addendum 1).docx May 2016

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Bosl/Brac _Arnot_Gumeni Undermining Study_Stage1_InterimFinal_ docx SRK Consulting: 453803: Arnot to Gumeni High Voltage Lines-Stage 1 Undermining Study (Interim) Pagee 7 Figure 4-4 Geological map showing Stratigraphy in relation to proposed routes Bosl/Brac 453803_Arnot_Gumeni