ASSESSMENT REPORT 77 GEMCO Eastern Leases Project GROOTE EYLANDT MINING COMPANY PTY LTD March 2016 NORTHERN TERRITORY ENVIRONMENT PROTECTION AUTHORITY Northern Territory Environment Protection Authority GPO Box 3675 Darwin Northern Territory 0801 © Northern Territory Environment Protection Authority 2016 Important Disclaimer This document has been prepared with all due diligence and care, based on the best available information at the time of publication. Any decisions made by other parties based on this document are solely the responsibility of those parties. The Northern Territory Environment Protection Authority and Northern Territory of Australia do not warrant that this publication, or any part of it, is correct or complete. To the extent permitted by law, the Northern Territory Environment Protection Authority and Northern Territory of Australia (including their employees and agents) exclude all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and other compensation, arising directly or indirectly from using, in part or in whole, any information or material contained in this publication. NORTHERN TERRITORY ENVIRONMENT PROTECTION AUTHORITY Contents Abbreviations ........................................................................................................... ii Glossary ...................................................................................................................iii Summary ..................................................................................................................iv Recommendations ..................................................................................................vii 1 Introduction ........................................................................................................ 1 1.1 Environmental impact assessment process .................................................... 1 1.2 Environmental impact assessment chronology ............................................... 2 1.3 Approval and regulatory framework ................................................................ 3 1.4 Ecologically sustainable development ............................................................ 3 2 Project ................................................................................................................ 4 2.1 Proponent ...................................................................................................... 4 2.2 Project description .......................................................................................... 5 2.3 GEMCO Mine ................................................................................................. 5 3 Regional setting ................................................................................................10 3.1 Location ........................................................................................................10 3.2 Ecological values ..........................................................................................11 3.3 Physical .........................................................................................................12 3.4 Transport network .........................................................................................12 3.5 Socio-economic aspects ...............................................................................12 4 Environmental impact assessment .................................................................13 4.1 Summary of environmental risks ...................................................................14 4.2 Ecology and biodiversity ................................................................................16 4.3 Rehabilitation and closure .............................................................................33 4.4 Water ............................................................................................................35 4.5 Erosion and sediment control ........................................................................42 4.6 Geochemistry ................................................................................................43 4.7 Tailings ..........................................................................................................46 4.8 Socio-economic aspects ...............................................................................46 4.9 Cultural heritage ............................................................................................47 4.10 Environmental Management ..........................................................................50 5 Conclusion ........................................................................................................52 6 References ........................................................................................................53 NORTHERN TERRITORY ENVIRONMENT PROTECTION AUTHORITY i Assessment Report 77 Abbreviations AAPA Aboriginal Areas Protection Authority ALRA Aboriginal Land Rights (Northern Territory) Act 1976 API Aerial Photograph Interpretation ALC Anindilyakwa Land Council AEP Annual Exceedance Probability CTMR Conceptual Tailings Management Report draft EIS Draft Environmental Impact Statement EARC East Arnhem Regional Council EA Act Environmental Assessment Act EAAP Environmental Assessment Administrative Procedures EIA Environmental Impact Assessment EIS Environmental Impact Statement ELR Exploration Licence in Retention EMP Environmental Management Plan EPBC Act Environment Protection and Biodiversity Conservation Act 1999 ESCP Erosion and Sediment Control Plan ESD Ecologically Sustainable Development GEMCO Groote Eylandt Mining Company Pty Ltd HRCDOR Haul Road Crossing Design Overview Report IR Infra-red ML Mineral Lease MNES Matters of National Environmental Significance MU Map Unit NT Northern Territory of Australia NT EPA Northern Territory Environment Protection Authority PAF Potentially Acid Forming NORTHERN TERRITORY ENVIRONMENT PROTECTION AUTHORITY ii Assessment Report 77 Glossary Advisory bodies Agencies having administrative responsibilities in respect of the proposed action the Australian The Australian Government Minister responsible for the Government Environment Protection and Biodiversity Conservation Act Minister 1999 Environmental The Environmental Impact Statement is the draft Impact Statement Environmental Impact Statement and the Supplement to the draft Environmental Impact Statement Environmental As defined by the Mining Management Act, an Mining Report Environmental Mining Report is a report about an operator's environmental performance in carrying out activities for mining minerals, taking into account: (a) the commitments given by, and the obligations imposed on, the operator in relation to an environmental assessment under the Environmental Assessment Act; and (b) the obligations of the operator under the management system for the mining site the Minister The Minister of the Northern Territory responsible for the Environmental Assessment Act the Project GEMCO Eastern Leases Project the Proponent The person, organisation or Agency responsible for the development and execution of the proposed action; that is Groote Eylandt Mining Company Pty Ltd the/this Report This Assessment Report 77 for the GEMCO Eastern Leases Project the Responsible The Minister of the Northern Territory primarily responsible Minister for authorising the proposed action; that is the Minister of the Northern Territory responsible for the Mining Management Act Commenter Person or person(s) from the public or an organisation that is not an advisory body whom provided written comment on the draft Environmental Impact Statement the Supplement The Supplement to the draft Environmental Impact Statement NORTHERN TERRITORY ENVIRONMENT PROTECTION AUTHORITY iii Assessment Report 77 Summary Environmental Impact Assessment (EIA) is a process for identifying the potential environmental impacts and risks of a proposed action, evaluating the significance of those impacts and risks and determining appropriate avoidance, minimisation/mitigation and offset measures to reduce those impacts and risks to acceptable levels. This Assessment Report (this Report) examines the EIA for the GEMCO Eastern Leases Project (the Project), proposed by Groote Eylandt Mining Company Pty Ltd (the Proponent). The Proponent proposes to develop and operate the Project, approximately 2 km east of the existing GEMCO Mine. Approximately 39 million tonnes (Mt) of manganese ore would be mined using open cut, strip mining methods from Exploration Licences in Retention ELR28161 (Northern Eastern Lease) and ELR28162 (Southern Eastern Lease). The Proponent proposes to transport the mined ore from the Project via a new haul road to the existing concentrator, and related facilities at the GEMCO Mine for ore processing and product export. The Project is intended to enable access to an additional mining area that would be operated as part of the existing mine, rather than an independent mine. Where possible, the Project would utilise infrastructure (e.g. concentrator, stockpiles, roads, etc.) at the existing mine and the Proponent anticipates that upgrades of this infrastructure would not be required. The Project workforce would be drawn from the workforce at the existing mine, and the Project would utilise the mine’s existing equipment fleet. Project operations would be undertaken concurrently with mining operations at the existing mine and ore mined as part of the Project would be