The use of native plant seeds is fundamental to large-scale rehabilitation and the re-establishment of self-sustaining ecosystems after high-impact mining activity has ceased. However, many of the biological attributes of seeds are often overlooked in large-scale rehabilitation programs. Multi-disciplinary, long-term research collaborations are required to improve seed-based mine rehabilitation. In this paper, we review the steps that BHP Western Australia Iron Ore (WAIO), a large iron ore mining company that operates in the Pilbara bioregion of north-west Western Australia, has taken over the past 9 years to ensure continuous improvement in rehabilitation procedures. We introduce the mining activities that WAIO undertake in the Pilbara, and emphasise specific examples of how research findings have led to incremental improvements in the seed management cycle, growth media management and mine rehabilitation practices. Specifically, we outline how the implementation of structured seed collection and storage programs has created the capacity to maintain high-quality seed stocks sufficient for 3–5 years of future rehabilitation. Research has documented the prevalence of seed dormancy in the flora (>70% of 105 species examined produce dormant seeds), with physical and physiological classes of dormancy most commonly encountered. We discuss the development of seed-treatments such as optimised wet-heat and dry after-ripening that have increased the germination capacity of many previously dormant seed batches. In addition, we highlight how seed enhancement technologies, such as hydro-priming with smoke-derived germination stimulants and polymer seed coating, and a greater understanding of the biological and physical limitations present in the growing environment, have vastly improved seedling emergence performance under field conditions for key framework Triodia species. Ongoing industry support (e.g. construction of a purpose-built rain manipulation shelter) has ensured research in the Pilbara will continue to unpack and resolve the complex challenges associated with seed regeneration of biodiverse native plant communities after mining.

BHP developed its original corporate closure framework in 2004, with an emphasis on standardising closure plan content and cost estimation. Since then, the framework has evolved with the release of 'Our Requirements for Closure' (OR Closure) in 2018, including the need for the development of optimised closure outcomes that result in enduring environmental and social benefits. OR Closure considers risks and opportunities to shareholder value and the communities and environment in which we operate. It drives toward optimised closure outcomes for our sites by balancing our values, obligations, safety, costs, and the expectations of external stakeholders. The OR purposefully shifts the development of 'closure plans' to 'closure management plans' to reflect the dynamic and integrated nature of successful closure planning from the earliest stages of exploration through to closure execution and beyond. This paper presents the revised closure framework, and how it incorporates the vision for the future state of closure planning within BHP, in its ongoing contribution to global development and its aspiration to leave a sustainable and positive legacy.

The International Council on Mining and Metals (ICMM) is an international organisation that brings together 27 mining and metal companies and over 30 regional and commodities associations to strengthen environmental and social performance and enhance mining's contribution to society. The Integrated Mine Closure: Good Practice Guide (2019a) presents a major update to ICMM's Planning for Integrated Mine Closure: Toolkit (2008). The guide is intended to support the goal of ICMM members, other responsible mining companies, and regulators in delivering a positive legacy while balancing environmental protection and social wellbeing with financial performance. The document provides mining companies with guidance intended to promote a disciplined approach to integrated closure planning and to increase the uniformity of good practices across the sector. Like the earlier version, guidance is provided on the key aspects of mine closure focused on an iterative process, from the earliest stages of knowledge gathering, engagement and planning. The updated guide reflects modern leading practice, with additional emphasis on the importance of social transitioning, progressive closure, and strategies for relinquishment and closure governance. The guide also includes a range of tools that can be utilised in formulating well-considered decisions when planning and executing closure. Successful integrated mine closure utilises a dynamic and iterative process that takes into account environmental, social and economic considerations at an early stage of mine development and runs through to closure. Fundamental to this process is the need to consider closure as an integral part of the mine operations' core business. The structure of the guide reflects this process, providing good practice guidance in delivering key elements of mine closure planning and implementation. This paper provides an overview of how the guide was developed and its contents. The guide was developed over an 18-month period by the ICMM Closure Working Group, which is made up of mine closure practitioners from leading global mining companies. As the guide was developed, further input and review was contributed by industry specialists, academia, and government representatives.

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BHP operates mines across the globe that, along with providing minerals required for societal development, also generate mine waste rock. This waste rock and exposed rock surfaces could potentially result in acid and metalliferous drainage (AMD) if the operations and materials are not properly identified and managed. Because AMD can occur long beyond the operational life of a mine, AMD risk can be a key risk driver in closure cost estimates. Therefore, to address this risk, BHP has developed a global AMD management standard to be implemented across all BHP's functions and operations, including closed sites. The purpose of the AMD management standard is to provide a management framework to support consistent, simple and sustainable global management of AMD risks. This in turn is designed to assist the reduction of uncertainty in closure cost estimates. Compliance to the AMD management standard informs several elements of BHP's closure management process, specifically baseline data and knowledge, risk assessment and ongoing implementation and review of Closure Management Plans. The AMD management framework, from which the standard is based, was adapted from industry bestpractice guidance to ensure its applicability to multiple regions and commodities. The AMD Management Framework consists of sequential requirements throughout the mining lifecycle from early mine studies, mine planning, mine development and operations, through to closure and throughout post-closure. The framework is iterative with an adaptive management approach designed to incorporate new data/information and management opportunities into AMD risk assessments and mine plan revisions. To promote the effective implementation and adoption of the standard, interactive consultation was undertaken with various groups across BHP's assets. This early consultation enabled key concerns to be raised and addressed, which is designed at promoting ownership of the AMD management standard. This paper discusses the framework to which BHP's AMD management standard is based and provides an outline for its planned implementation.