Caroona Coal Project Application for Gateway Certificate Appendix B Agricultural Resource Assessment March 2014
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Caroona Coal Project Application for Gateway Certificate Appendix B Agricultural Resource Assessment March 2014 Agricultural Resource Assessment for Gateway Application: “Caroona Coal Project” Caroona, NSW Prepared for BHP Billiton Ltd; in conjunction with Resource Strategies Pty Ltd Dr. David McKenzie McKenzie Soil Management Pty. Ltd. Orange NSW Agricultural Resource Assessment for Gateway Application: “Caroona Coal Project” DOCUMENT CONTROL Prepared for client: BHP Billiton First draft preparation: Author: D McKenzie Reviewer: T MacKillop Date: 18.2.14 Second draft: Author: D McKenzie Reviewer: T MacKillop Date: 9.3.14 Final draft: Author: D McKenzie Reviewer: D McKenzie Date: 23.3.14 ACKNOWLEDGEMENTS Valuable assistance with field work was provided by Dr Ian Hollingsworth (CPSS - 3) (Horizon ESSE), Phil Sevil and Bruce Hartin. Important contributions also were provided by Lindsay Hyde and David McMillan (McKenzie Soil Management) and Incitec Pivot Laboratory. CITATION OF THIS REPORT McKenzie DC (2014) Agricultural Resource Assessment to Support a Gateway Application for the Caroona Coal Project. A report prepared for BHP Billiton by McKenzie Soil Management Pty Ltd, Orange NSW, February 2014. DISCLAIMER This report has been prepared in accordance with the brief provided by BHP Billiton via Resource Strategies Pty Ltd. It has relied upon information collected under the weather conditions and time schedule specified herein. All information contained within the report is based only on the aforementioned circumstances. The report is for the use of BHP Billiton only and McKenzie Soil Management Pty Ltd will take no responsibility for its use by other parties. INFORMATION SOURCES AND REFERENCING This report was derived from an extensive range of information sources including literature review and discussions with colleagues and landholders. The author has sought to ensure that sources for his use of text, diagrams, maps and images are provided in the report. If the author inadvertently has failed to adequately acknowledge a source of material used, he would appreciate prompt notification so that the matter can be corrected in the electronic version of the document and a full acknowledgement provided. COPYRIGHT © 2014, McKenzie Soil Management Pty Ltd and BHP Billiton. This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without written permission from McKenzie Soil Management Pty Ltd and BHP Billiton, 2014. McKenzie Soil Management Pty. Ltd. ii Agricultural Resource Assessment for Gateway Application: “Caroona Coal Project” Contents EXECUTIVE SUMMARY ES-1 1 INTRODUCTION 1 2 PROJECT DESCRIPTION 1 2.1 Project Overview 1 2.2 Geological Features 5 2.3 Underground Mining Operations and Surface Infrastructure 8 3 PROJECT SITE DESCRIPTION 11 4 SOIL RESOURCES 13 4.1 Review of Existing Information 13 Parent Materials for Soil Formation 13 Soil Types, Soil Landscapes, Inherent Soil Fertility and Land and Soil Capability 13 SPADE Soil Profile Database 14 Strategic Agricultural Land 14 4.2 Soil Survey Methodology 14 Field Survey 15 Field Soil Observations/Testing 17 Laboratory Soil Testing 18 4.3 Soil Types and Mapping 20 Soil Landscape Units 20 ASC Soil Types 22 4.4 Soil Conditions for Plant Growth 28 Soil Depth, Texture and Waterholding Capacity 28 Waterlogging Hazard 29 Soil Stability in Water – Dispersion and Slaking 29 Compaction Status 30 Structure Self-repair Ability 30 Salt Concentrations 30 pH Imbalance 30 Nutrients 30 Soil Carbon and Soil Biological Health 31 4.5 Inherent Soil Fertility 31 5 BIOPHYSICAL STRATEGIC AGRICULTURAL LAND ASSESSMENT 32 6 LAND AND SOIL CAPABILITY CLASSES 38 7 POTENTIAL IMPACTS ON SOIL RESOURCES 42 7.1 Post-mining Land and Soil Capability Assessment 42 7.2 Soil Resource Management Measures 43 Stripping 43 Stockpile Management 44 McKenzie Soil Management Pty. Ltd. iii Agricultural Resource Assessment for Gateway Application: “Caroona Coal Project” Application of Soil on Rehabilitated Landforms 45 Remediation of Soil Compaction Beneath Infrastructure Areas 45 Rehabilitation Management Plan 45 7.3 Remediation Strategies for Subsidence Impacts 45 8 CONCLUSION 46 9 REFERENCES 47 List of Figures Figure 1 Regional Location Figure 2 Project Area and Surrounds and Soil Test Pit Locations Figure 3a Relevant Land Ownership Figure 3b Relevant Land Ownership List Figure 4 Geology of the Project Area Figure 5 Indicative Mining Layout and Surface Infrastructure Figure 6 NSW Government Assessment of BSAL in the Vicinity of the Project Figure 7 The Link Between ASWAT Results and Soil Management Options Figure 8 Project Soil Landscape Units Figure 9 Photographs of Soil Types – Dominant ASC Orders Figure 10 Photographs of Soil Types – Sub-Dominant ASC Orders Figure 11 Flow Chart for Site Verification of BSAL Figure 12 Project Soil Landscape Units - with Location of BSAL Sites Figure 13 Location of BSAL Figure 14a Project Land and Soil Capability - Salt Sensitive Scenario Figure 14b Project Land and Soil Capability - Salt Tolerant Scenario List of Tables Table 1 Overview of the Caroona Coal Project Table 2 Details of Field Work Campaigns Table 3 The Relationship between the Emerson Aggregate Stability Test and the ASWAT Test Table 4 Soil Types Associated with the Nine Soil Landscape Units Identified in the Project Assessment Area Table 5 Soil Types Identified; Classified According to the ASC and Great Soil Groups Table 6 BSAL Status of Soil Landscape Units in the Project Assessment Area Table 7 Estimated Pre-mining and Post-mining LSC Class McKenzie Soil Management Pty. Ltd. iv Agricultural Resource Assessment for Gateway Application: “Caroona Coal Project” List of Soil Maps Map 1 Pit Positions in Relation to BSAL Slope Categories Map 2 Soil Types - Australian Soil Classification Map 3 Depth to Rock Map 4 Plant Available Water (TAW) Map 5 Depth to Waterlogged Layer Map 6 Depth to Layer with Lime Map 7 Dispersion (ASWAT Scores) Map 8 Dispersion (ESP Values) Map 9 Compaction Severity (SOILpak Score) Map 10 Cation Exchange Capacity Map 11 Salinity (Electrical Conductivity – ECe) Map 12 pH (CaCl2) Map 13 Phosphorus (Colwell P) Map 14 Organic Carbon List of Appendices Appendix 1 Soil Landscapes of the Curlewis and Tamworth Sheets 1:100,000 Appendix 2 Soil Landscape Unit Description (Banks 1995) Appendix 3 NSW Government Soil Type Mapping Appendix 4 NSW Government Inherent Soil Fertility Map Appendix 5 NSW Government Land and Soil Capability Classes Appendix 6 Pre-existing Soil Information from the SPADE Website Appendix 7 Slope Maps for LSC Analysis Appendix 8 BSAL Assessment Matrix Appendix 9 LSC Methodology Appendix 10a LSC Assessment Matrix - Salt Sensitive Scenario Appendix 10b LSC Assessment Matrix - Salt Tolerant Scenario List of Attachments (provided in electronic version) Attachment A Overview Data: Pits 1 to 404 Attachment B Layer Data: Pits 1 to 404 Attachment C Soil Structure Details: Pits 1 to 404 Attachment D Laboratory Data: Pits 1 to 404 Attachment E Photographs of Soil Profiles: Pits 1 to 404 McKenzie Soil Management Pty. Ltd. v Agricultural Resource Assessment for Gateway Application: “Caroona Coal Project” EXECUTIVE SUMMARY The Caroona Coal Project (the Project) is a proposed underground coal mining operation with an operational life of approximately 30 years. It is located 14 kilometres (km) north-west of Quirindi and 40 km south-southeast of Gunnedah in the New England North West region of New South Wales (NSW). A soil survey was conducted by McKenzie Soil Management and associates during 2013 as part of the NSW Gateway Application for the Project. The survey included photography, description and sampling of 404 backhoe excavated soil pit profiles. Based on the site inspection, soil survey and laboratory analysis results, an assessment of biophysical strategic agricultural land (BSAL) status of the survey area was conducted in accordance with the Interim Protocol for Site Verification and Mapping of Biophysical Strategic Agricultural Land (NSW Government 2013). Within the Project Assessment Area, three soil landscape units are considered to be BSAL dominant, comprising an area of approximately 2,040 hectares (ha). In addition, four smaller clusters of BSAL (beyond the BSAL dominant soil landscape units) totalling 175 ha are also located within the Project Assessment Area, however only two of these clusters are located above the proposed underground mining area. Accordingly, 2,215 ha of Protocol Verified BSAL1 is considered to be located within the Project Assessment Area. The remainder of the Project Assessment Area has a broad range of constraints which preclude the land from being classified as BSAL, including subsoil with salinity, alkalinity and sodicity problems, excessive slope (>10%) and rock close to the soil surface. According to the NSW Government’s regional mapping, Vertosols on the alluvial plains surrounding Doona Ridge and Nicholas Ridge are classified as BSAL however this study has shown that these sub- sections of the study area are in fact non-BSAL because of strongly saline and alkaline subsoil. Possible impacts to agricultural productivity as a result of the Project would be associated with temporary loss of land due to construction of mine infrastructure (e.g. surface facilities) and potential subsidence impacts. With the implementation of proposed management measures for surface cracking, topographical depressions and localised slope changes, it is considered that there would be no significant adverse change to