Mine planning and rehabilitation advice
Proponents of mining operations are encouraged to ensure progressive rehabilitation and post-mining land uses are properly considered early in the design stages.
The NSW Resources Regulator encourages proponents of mining operations to ensure progressive rehabilitation and post-mining land uses are properly considered early in the design stages and before lodging a development application.
Avoiding poor environment outcomes
Often, development applications for mining projects do not contain enough information on rehabilitation or proposed post-mining land uses and lack rigorous justifications and risk assessments. This has the potential to result in poor environmental outcomes. For instance, the Leading practice sustainable development program for the mining industry's handbook on mine rehabilitation (Commonwealth of Australia, September 2016 date) states:
- opportunities and threats should be identified early so that mining operations do not reduce rehabilitation options (p.6)
- effective and early planning helps to minimise rehabilitation costs (p.6).
Consult the NSW Resources Regulator early
To improve regulatory coordination at the planning, operational and closure stages of the mine life cycle, proponents should consult with the Regulator at the early stages of the mine planning and design process. This should occur before lodging a development application for a new mine or modification of an existing mine.
As stated in the Leading practice sustainable development program for the mining industry’s handbook on mine closure (Commonwealth of Australia, September 2016, page 60)
“Closure plans evolve throughout the life of a mine and must provide more detail as the mine nears decommissioning and closure.”
As such proponents are also encouraged to consult with the Regulator throughout the operational and closure stages of a mine in relation to the preparation of rehabilitation management plans (formerly mining operation plans), rehabilitation objectives and completion criteria as well as rehabilitation completion reports.
Contact the Mining Act Inspectorate on 1300 814 609 (option 2, then 5) or via email at firstname.lastname@example.org.
Rehabilitation and securities panel (RASP)
The Regulator has established the rehabilitation and securities panel (RASP) to aid continual improvement in the regulatory oversight of rehabilitation and mine closure across the mining sector.
RASP provides valuable feedback to proponents at the early stages of mine planning to ensure rehabilitation and post-mining land uses are properly considered early in the design stages and before lodging a development application. In addition, proponents are also to encouraged to consult with RASP for feedback as required in the development and execution of rehabilitation strategies during the operational and closure phases of a mine.
The Regulator encourages proponents of new mining operations (including extensions to existing mines and modifications to existing approvals) to seek feedback from the RASP before lodging development applications with the consent authority.
RASP is made up of senior members of the Mining Act Inspectorate including:
- Director Compliance
- Principal Inspector Environment and Rehabilitation Operations
- Manager Compliance Operations
- Manager Environmental Operations
Presentations to RASP
Presentations to RASP can be arranged by contacting the Mining Act Inspectorate on 1300 814 609 (option 2, then 5) or via email at email@example.com
At least 10 days before the presentation, proponents should email their presentation along with any supporting information to firstname.lastname@example.org
Presentations to RASP should demonstrate how the project:
- addresses the relevant Secretary’s Environmental Assessment Requirements (SEARs) (see below)
- has considered post-mining land uses that minimise sterilisation of land
- has considered potential barriers or limitations to achieving successful rehabilitation, including how controls have been incorporated into the design of a mine to maximise rehabilitation outcomes (e.g. alternative tailings management approaches that minimises the requirement to construct tailings dams)
- has identified suitable post-mining land uses (taking into account local and regional planning controls; adjacent and surrounding landforms and land uses; proposed rehabilitation outcomes of any neighbouring mines)
- justifies the proposed mine design, rehabilitation schedule and final landform, including:
- why has the mine design been chosen (incorporating resource, design, commercial/economic constraints)?
- why is this the best outcome (including justification for final voids, high walls and low walls, tailings dams etc.)?
- why is this an improvement to any the currently approved project (as relevant)?
Secretary's environmental assessment requirements
The Regulator recommends that the following environmental assessment requirements are addressed, as relevant, in any development application or modification to a development consent.
The environmental assessment that accompanies the development application must include a description and assessment of any exploration activities that will be undertaken throughout the mine life. This must also address the progressive rehabilitation of areas disturbed by exploration activities.
The environmental assessment that accompanies the development application must include a separate section entitled ‘Rehabilitation Strategy’ which addresses the following matters as relevant.
Final land use(s)
Identification and assessment of final (i.e. post-mining) land use options.
Identification and justification of the preferred final land use outcome(s), including a discussion of how the final land use(s) are aligned with relevant local and regional strategic land use objectives and surrounding land uses.
Identification of how the rehabilitation of the project will relate to the rehabilitation strategies of any neighbouring mines within the region, with a particular emphasis on the coordination of rehabilitation activities along common boundary areas.
Rehabilitation objectives and domains
Inclusion of a set of project rehabilitation objectives that clearly define the outcomes required to achieve the final (post-mining) land use for each mining domain. Each mining domain must have a stated final land use and rehabilitation objectives (which describe the desired features and/or characteristics of the final land use domain). Rehabilitation objectives must include, where relevant, target vegetation communities.
The expected time frames for progressive rehabilitation.
Mine layout and scheduling, including maximising opportunities for progressive final rehabilitation. The final rehabilitation schedule should be mapped against key production milestones (i.e. ROM tonnes) of the mine layout sequence before being translated to indicative timeframes for each stage of rehabilitation throughout the mine life. The mine plan should maximise opportunities for progressive rehabilitation.
Conceptual final landform design
Inclusion of drawings at appropriate scales identifying key attributes of the final landform, including final landform contours, section views, significant water management features/structures, the location of the proposed final land use(s) and integration with existing and surrounding landforms.
Barriers or limitations to effective rehabilitation
Identification and description of those aspects of the site or operations that may present barriers or limitations to effective rehabilitation, including an assessment of high risk rehabilitation landforms (such as high walls, steep slopes, waste rock dumps, etc). This should include (as relevant):
- an assessment and life of mine management strategy of the potential for geochemical constraints to rehabilitation (e.g. acid metalliferous drainage, spontaneous combustion etc.), particularly associated with the management of overburden/interburden and reject material. This assessment should utilise any relevant data from previous exploration programs to characterise the geochemical properties of the materials and identify appropriate management strategies. This should include any emplacement strategies (e.g. how materials are emplaced to minimise oxidation and leachate), capping strategies, the source of capping materials, associated volume of capping materials required, routine sampling and testing;
- the processes that will be implemented throughout the mine life to design and ensure the long term stability of the rehabilitated landforms, including how characteristics of the existing and surrounding landform can be incorporated into the final landform design. This should include identifying and adopting geomorphic design principles to achieve a natural and stable landform outcome. It should also include a constraints and opportunities analysis of alternative final landforms giving consideration to geotechnical stability, geomorphic stability (soil types, soil erosion, etc), water management, integration with the characteristics of the surrounding natural landform and minimising sterilisation of land post-mining. For large and complex sites, there should be a commitment to undertake landform evolution modelling throughout the mine life to address long-term erosion and stability risks;
- a life of mine tailings management strategy, which details measures to be implemented to avoid the exposure of tailings material that may cause environmental risk, as well as to ensure the geotechnical and geomorphic stability of the rehabilitated landform of the tailings storage facility. This should include any capping strategies, the source of capping materials and associated volume of capping materials required. It should also include a constraints and opportunities analysis of different tailings management techniques (e.g. co-disposal, dewatering tailings, integrated landforms, etc) and of alternative techniques to reduce the amount of tailings and reliance on conventional tailing storage facilities. Justification of the proposed tailings management strategy should be provided to demonstrate that it is the most feasible and environmentally sustainable option;
Where a void, is proposed to remain as part of the final landform, include:
- a constraints and opportunities analysis of final void options, including backfilling, to justify that the proposed design is the most feasible and environmentally sustainable option to minimise the sterilisation of land post-mining;
- a preliminary geotechnical assessment to identify the likely long term stability risks associated with the proposed remaining high wall(s) and low wall(s) along with associated measures that will be required to minimise potential risks to public safety; and
- outcomes of the surface and groundwater assessments in relation to the likely final water level in the void. This should include an assessment of the potential for fill and spill along with measures required be implemented to minimise associated impacts to the environment and downstream water users.
Where the mine includes underground workings:
- determine (with reference to the groundwater assessment) the likelihood and associated impacts of groundwater accumulating and subsequently discharging (e.g. acid or neutral mine drainage) from the underground workings post cessation of mining; and
- consideration of the likely controls required to either prevent or mitigate against these risks as part of the closure plan for the site.
Where an ecological land use is proposed, demonstrate how the revegetation strategy (e.g. seed mix, habitat features, corridor width, aspect, etc.) has been developed in consideration of the target vegetation community(s).
Where the intended land use is agriculture, demonstrate that the landscape, vegetation and soil is capable of supporting this land use. In addition, demonstrate that the proposed location of the rehabilitated agricultural area is not isolated within the landscape and that there is ready access to water and relevant infrastructure (e.g. power, roads etc.) to support agricultural activities.
Relevant policies and guidelines
Consider the following relevant policies and guidelines.
- Mine Rehabilitation (Leading Practice Sustainable Development Program for the Mining Industry, Australian Government, 2016)
- Mine Closure (Leading Practice Sustainable Development Program for the Mining Industry, Australian Government, 2016)
- Strategic Framework for Mine Closure (ANZMEC-MCA, 2000)
- Guidelines on Tailings Dams – Planning, Design, Construction, Operation And Closure – Revision 1 (ANCOLD, July 2019)
- Integrated Mine Closure: Good Practice Guide (ICMM, 2019)