Mine 'rehabilitation' and 'closure' - What's the difference?

Last modified by Corinne Unger on 2016/06/07 16:40

Title/Topic/Mine 'Rehabilitation' and 'Closure' – What’s the difference?
Executive summary

Mine rehabilitation and mine closure are different but related activities. Rehabilitation is often the progressive or ‘staged’ implementation of the closure design, undertaken while the mine is operating.  Rehabilitation provides the testing, trialling, investigation and proving aspects of establishing stable and useful landforms created by mining. Together rehabilitation and closure aim to create safe, stable and non-polluting landforms with sustainable post-mining land uses. Often rehabilitation focuses on biophysical aspects whilst ‘closure’ addresses the full gamut of socio-economic and environmental goals associated with mine completion. Rehabilitation is a sub-set of closure.

Both rehabilitation and closure have planning, implementation and review phases which feed into continual improvement of plans, works and evaluation. This summary aims to explore the roles of each in developing good outcomes for environments and communities both during the life-of-mine as well as in developing agreed and sustainable post-mining land uses. The closure design provides the framework and rehabilitation planning processes implement the concept. Rehabilitation may be seen as a 'control measure' for risk management of wastes, or it can be seen as something which is engineered into design and then becomes embedded in good closure design. Applying the latter approach, could mitigate long term legacy risks thereby adding value to a mining operation. The worst case scenario is to arrive at the end of a mine's life with little or no clarity about rehabilitation and closure objectives or how to achieve them.

Legislation and guidance in QueenslandIn Queensland, the environmental regulator of mining is the Department of Environment and Heritage Protection (DEHP). This agency has a guideline ‘Rehabilitation requirements for mining resource activities’ under the Environmental Protection Act 1994. Rehabilitation and closure are referred to in this guidance as separate activities with a greater focus on rehabilitation. While closure planning is something many companies automatically undertake as part of good business, the Queensland legislation does not specify the requirement for a closure plan. This aspect may be addressed through the requirements of each operation’s Environmental Authority. In Western Australia, their Mine Closure Guidelines (2015) are different in that they are focussed more on closure planning with a regular review cycle. By having both agencies, EPA (Environmental Protection Authority) and DMP (Department of Minerals and Petroleum) contributing to these Guidelines, they bring together the requirements of both pieces of legislation for closure. In this way they present more of a whole of government approach to Closure.
Closure guidance

Designing for closure should commence during the earliest stages of mine planning for a greenfields mine. During exploration this means for example characterising the wastes to an appropriate level of detail when evaluating ore to determine geological risks for the environment. During pre-feasibility and feasibility studies, the closure concept can take shape considering all aspects of closure risks and opportunities.

A brownfields mine (former mine being recommenced) can also include closure design from its outset however ‘legacy’ mine landforms maypose constraints on that design. The ICMM, 2008 guidance 'Planning for Integrated Mine closure: Toolkit'  (Figure 2) highlight the value of designing for closure from the outset in order to maximise options for closure and minimise risks.

Australia has a Strategic Framework for Mine Closure ANZMEC/MCA, 2000 which provides principles for all jurisdictions in Australia to apply.

Decommissioning can be planned for in advance as part of closure design and planning. Decommissioning is a task which occurs at the end of mining operations as part of closure implementation.

The perception may be that closure planning is something to worry about, only at the end of a mine's life. However, it is important to understand the requirement to embed good closure design in mine design from the outset. Key decisions are made early about mining and processing methods, waste containment and management and these decisions much be made early and with closure in mind. If not significant legacy liabilities can inadvertently be created.

Through the life of the mine, the initial closure design and post-mining landscape and land use concept will need to be refined. The process of stakeholder engagement will need to address how agreement is reached on post-mining land use(s). Understanding stakeholder needs will enable their requirements to be understood and incorporated into evolving designs. Stakeholders include other government agencies as well as different levels of government as applicable. Stakeholders also include land owners and neighbours. Sometimes community groups and catchment NRM (Natural Resource Management) bodies, will have a role in closure design and rehabilitation works. Each mine is unique as is its environmental and social context. All aspects will be considered under good closure design and planning. [see also short, medium and long term plans]. Social aspects of closure must also consider changes in the socio-economic context and how communities will transition through this process.

Mine closure and completion, Leading Practice Sustainable Development Program for the mining industry (DITR 2006). Mine closure and completion are terms used here. Completion requires relinquishment and the transition of mine rehabilitated land to a subsequent land use.

Rehabilitation guidance

Queensland’s rehabilitation guidance sets the scene with a policy and legislative framework, discusses general and specific rehabilitation goals. The importance of rehabilitation objectives for a mine, as well as indicators and completion criteria are also explained. The Certificate of Surrender process is outlined. Dealing with historic mines and evaluating their rehabilitation is also explained. A note is made that generally rehabilitation completed prior to 2001 would not be assessed against current legislation or policy. Rehabilitation generally refers to the tasks planned and undertaken during the life of the project to stabilise disturbed areas no longer required for production. This may include waste rock dumps/ spoil piles which are progressively constructed in line with the closure concept. It may also include areas of redundant infrastructure which may be decommissioned and removed. Rehabilitation has a focus on leaving safe, stable and non-polluting landform with sustainable land uses which aims to capture all closure –requirements.

The leading practice sustainable development series of booklets includes both rehabilitation and closure booklets

The rehabilitation booklet (DITR, 2006) contains the following topics; rehabilitation objectives, soil handling, earthworks, revegetation, soil nutrients, fauna return, maintenance, success criteria and monitoring. Managers with responsibility for rehabilitation should be able to adapt this information to their own particular situations when planning a rehabilitation strategy.

Planning, implementing and reviewing are tasks relevant to both closure design and planning as well as rehabilitation. Continual improvement results only when the findings of reviews (this means review of closure design and plans and works as well as review and monitoring of rehabilitation plans and works) informs future planning and implementation.

A review of rehabilitation in Queensland indicates here may be a gap between rehabilitation and relinquishment (Glenn et al, 2014). The authors cite experience and research which indicates that in many cases there is inadequate guidance for companies on how to develop clear rehabilitation goals, plans and monitoring systems. Without clarity on rehabilitation requirements, it is difficult for companies to be confident that their rehabilitation will be deemed ‘successful’ by regulators.

The closure process not only addresses rehabilitation, but all aspects of decommissioning, decontamination of contaminated land, stable landforms, post-mining land uses, engagement and agreement on land uses, legal and administrative arrangments for closure as well as preparing the workforce, contractors and community for the socio-economic changes due to closure.

Rehabilitation implements the closure conceptRehabilitation involves the tasks associated with transferring the closure concept to reality ‘on-the ground’. Rehabilitation must address the task of creating safe and stable landforms which support a particular land use which meets agreed land uses. For Central Queensland coal mines this may involve returning mine-disturbed lands to grazing and/or native ecosystems or a range of other uses. Many more post-mining land use options exist however a systematic examination of limitations and opportunities must be undertaken through closure risk assessment. The role of final voids must also be integrated into closure design. Sometimes above ground landforms (spoil and washery wastes) can become the focus of rehabilitation however, voids too require careful closure design attention to ensure benefical post-mining void water uses wherever possible. There have been several ACARP studies on this for open cut coal mines.
Community expectationsRehabilitation and closure are multi-disciplinary and integrated with operational planning if effectively carried out. Community expectations and actual stakeholders due to a range of factors may to change over time. Mining operations mindful of this will seek out new knowledge and lead with the application of that knowledge to stay ahead of community expectations. This leadership is likely to provide greater assurance of a successful transition to closure. Even planned closures can have deadlines changed due to changes in demand for a particular commodity. Markets influence the life of a mine. Communities can also influence the life of a mine particularly if social license is withdrawn.
Figureinsert diagram from ICMM 2008
References(s)

http://search.informit.com.au/documentSummary;dn=373135066051320;res=IELAPA

Mined land rehabilitation - is there a gap between regulatory guidance and successful relinquishment?

AusIMM Bulletin
Issue 3 (Jun 2014)

Glenn, Vanessa; Doley, David; Unger, Corinne; McCaffrey, Nic; McKenna, Phill; Gillespie, Melina; Williams, Elizabeth

Abstract: The rehabilitation of land disturbed by mining is a statutory requirement in Australia. Effective rehabilitation is essential for maintaining a 'social licence to operate'. It reduces risk for mining companies by minimising residual risk payments, reducing administrative uncertainties at closure and creating an agreed transition to post-mining landscapes.

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Created by Corinne Unger on 2016/03/01 17:31
    
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