Rehabilitation compliance activities

This is a targeted assessment of how a mine site is managing the key processes and activities required as part of the decommissioning of built infrastructure. The activities include:

• removal, demolition and/or dismantling buildings and infrastructure
• structural works to make retained buildings and infrastructure safe
• heritage assessment and management
• sealing mine openings and boreholes
• identification and remediation of hazardous areas.

The decommissioning process may occur after the end of mining or progressively over the life of an operation. It is recognised that this information may be conceptual during the initial stages of an operation.

The objectives include:

• ensuring the range of risks and opportunities associated with demolition and decommissioning are identified and appropriate controls are in place
• ensuring the effective environmental management, including removal, of any contaminated materials and hazardous items (for example radioactive density gauges) or materials (such as asbestos)
• ensuring the effective decommissioning, removal and/or augmentation of the mine water management system including any dams prescribed by the Dams Safety Act 2015
• identifying the potential timing of decommissioning and demolition activities
• ensuring that obligations under the Heritage Act 1977 are identified and met by the titleholder
• ensuring underground mine workings are rendered safe and sealed for public safety
• ensuring the substrate following decommissioning is suitable to support the proposed revegetation outcome (e.g. native or agricultural rehabilitation)
• where buildings and infrastructure are to be retained as part of the post-mining land use, measures are implemented to ensure they are fit for purpose and risks to public safety are minimised
• ensuring control measures are validated via monitoring, inspections are recorded to enable risks to be appropriately addressed
• ensuring the mine site has engaged workers with the appropriate skills and experience in relation to decommissioning
• ensuring decommissioning and rehabilitation is integrated into mine planning systems.

Mine sites need to implement the above controls based on the risks, the scope of activities being undertaken at the site, and any regulatory requirements or agency approvals required for decommissioning and/or demolishing infrastructure.

This TAP comprises a targeted assessment of how a mine site is managing materials and soils to achieve sustainable rehabilitation outcomes. This includes how a mine is managing any potential soil or material deficits. Further details are provided in the Guidance note. (PDF, 215.11 KB)

The objectives of this targeted assessment include:

• ensuring the range of risks associated with materials and soils are identified and appropriate controls are in place to facilitate sustainable rehabilitation outcomes
• identifying potential constraints/opportunities to maximise the salvage of soil resources for use in rehabilitation
• ensuring an inventory of soil resources and materials (e.g. inert capping material, etc) has been defined to ensure the needs for rehabilitation of the final land use can be met
• ensuring the selective handling and management of mine materials (e.g. overburden, tailings, reject materials etc.) to address potential geochemical and geotechnical constraints for rehabilitation
• ensuring the substrate is suitable to support proposed revegetation outcome (e.g. native or agricultural rehabilitation)
• ensuring control measures are validated via monitoring, inspections are recorded to enable risks to be appropriately addressed
• ensuring the mine site has engaged the appropriate skills and experience in relation to materials and soils management
• ensuring rehabilitation is integrated into mine planning systems
• ensuring techniques and measures have been developed and implemented to salvage, protect and maintain biological resources (e.g. topsoil, subsoil, seed bank, plant material, logs, hollows etc.) for use in rehabilitation.

The specific need for mine sites to implement the above controls will be based on the risks as well as scope of activities being undertaken at the site. For example, where there are no more areas proposed to be cleared as part of future mining activities, this aspect of the assessment will not be relevant.

A materials and soils management TAP covering 51 mines was conducted from March 2020 to December 2020. The final report can be accessed here – Targeted Assessment Program Materials And Soil Management To Support The Post-Mining Final Land Use March – December 2020 (PDF, 1.57 MB)

This is a targeted assessment of how a mine site is establishing the final approved landform to achieve sustainable rehabilitation outcomes.

The objectives include:

• ensuring the range of risks associated with establishing the approved final landform are identified and appropriate controls are in place identifying potential constraints and opportunities to achieve the approved final landform, including geotechnical/geochemical issues, incorporation of surrounding landforms (for example macro and micro-relief) and visual amenity
• ensuring the location, treatment and/or rehabilitation of water management infrastructure is integrated into the final landform
• ensuring design and management measures to construct the final landform over reject emplacement areas and tailings dams will be to a condition/capability that supports the final land use
• identifying the key design features for final voids, highwalls and low walls and ensuring the design minimises impacts to public safety and reduces the sterilisation of land available for future final land uses
• ensuring the construction of any creek or river diversion works that will form part of the final landform will be  sustainable in the long term
• ensuring control measures that are validated via monitoring, inspections are recorded to enable risks to be appropriately addressed
• ensuring the mine site has engaged workers with the appropriate skills and experience  related to landform establishment
• ensuring landform establishment and rehabilitation are integrated into mine planning systems
• ensuring techniques and measures have been developed and implemented to achieve the final landform.

We consider a number of factors when assessing how mine operators identify, refine and implement critical controls associated with landform establishment. For further information see our Guidance note – Landform Establishment TAP assessment (PDF, 235.4 KB).

A key component of our compliance model is to educate and engage the regulated community. This includes helping to exchange information about leading practice associated with rehabilitation landform design.

We engaged Associate Professor Greg Hancock, School of Environmental and Life Sciences (Earth Sciences) at the University of Newcastle, to provide advice on the appropriate use of landform evolution modelling and consideration of geomorphic design principles for mine rehabilitation landforms. He is a recognised expert on the use of landform evolution modelling for the assessment of the design mine rehabilitation landforms for long-term stability.

Information provided by Associate Professor Hancock has been incorporated into a Q&A document specifically addressing landform evolution modelling and geomorphic design principles for mine rehabilitation landforms. This may assist mine operators in the design and construction of final landforms to achieve long-term stability and fulfil their rehabilitation obligations. Access the Q&A guidance here (PDF, 311.34 KB) (PDF, 311.34 KB).

This is a targeted assessment of how a mine site is managing revegetation to achieve sustainable rehabilitation outcomes.

The objectives include:

• ensuring the range of risks associated with growth medium development and revegetation are identified and appropriate controls are in place identifying potential constraints and opportunities identifying any studies required 
• ensuring control measures are validated via monitoring, inspections are recorded to enable risks to be appropriately addressed
• ensuring the mine site has engaged workers with the appropriate skills and experience related to revegetation
• ensuring revegetation and rehabilitation are integrated into mine planning systems
• ensuring techniques and measures have been developed and implemented to achieve the intended revegetation outcome (e.g. native ecosystem and or agricultural land use).

The Regulator considers a number of factors when assessing how mine operators identify, refine and implement critical controls associated with revegetation. Information that may assist mine operators understand the range of issues that are assessed by the Regulator as part of the revegetation TAP is contained in our TAP Guidance note – Revegetation (PDF, 161.71 KB).

The TAP comprises a targeted assessment of groundwater and surface water management to ensure measures have been identified and implemented to facilitate sustainable rehabilitation outcomes. The objectives of this targeted assessment include: 

• ensuring the range of risks associated with groundwater and surface water management are identified and appropriate controls are in place to facilitate sustainable rehabilitation outcomes. 
• determine geochemical constraints that may impact groundwater and surface water management. 
• a groundwater/surface water strategy is designed to limit release of contaminated water to the environment. 
• compliance with the regulatory obligation to commence rehabilitation as soon as reasonably practicable and the achievement of the final land use The Regulator considers a number of factors when assessing how mine operators identify, refine and implement critical controls associated with groundwater and surface water management.

Information that may assist mine operators understand the range of issues that are assessed by the Regulator as part of the groundwater and surface water TAP is contained in our TAP Guidance note – Groundwater and surface water (PDF, 123.97 KB).

The TAP comprises a targeted assessment of tailings storage facilities water management to ensure measures have been identified and implemented to facilitate sustainable rehabilitation outcomes. The objectives of this targeted assessment include: 

• ensuring the range of risks associated with tailings management are identified and appropriate controls are in place to facilitate sustainable rehabilitation outcomes. 
• determining geochemical and geotechnical constraints of tailings and Tailings Storage facilities (TSF) construction materials, to enable management strategies to be implemented during the TSF construction phase. 
• controlling or limiting the release of contaminants from the TSF or other form of tailings containment 
• tailings consolidation/settlement is maximised during placement to reduce impacts from settlement post closure. 
• ensuring tailings deposition maintains adequate environmental freeboard. 
• TSF capping provides a final barrier to contain tailings and prevent release to environment, manage seepage and to support final landuse 
• ensuring the TSF containment structure (embankments) and capping is protected from scour/erosion from water movement resulting from rainfall 
• compliance with the regulatory obligation to commence rehabilitation as soon as reasonably practicable and the achievement of the final land use 

The Regulator considers a number of factors when assessing how mine operators identify, refine and implement critical controls associated with tailings management. Information that may assist mine operators understand the range of issues that are assessed by the Regulator as part of the tailings management TAP is contained in our TAP Guidance note – Tailings Management (PDF, 129.84 KB).

A planned inspection program was undertaken in 2019 and 2020 to assess how mine operators were identifying and managing risks associated with hazards that affect worker safety (WHS Act considerations) and the environment (Mining Act considerations). Further details regarding this program can be accessed here. 

The assessment findings report can be accessed here: 

• Tailings management to support post-mining final land use - Planned inspection program November 2019 to May 2022 (PDF, 922.59 KB)

Participant sites will be notified up to two weeks before we conduct a TAP. This may include a request for specified management plans (such as the rehabilitation management plan), records, monitoring data and other relevant supporting documentation (such as site-specific rehabilitation risk assessments). The mine will also be notified of:

• assessment visit schedules
• assessment team composition
• focus areas for the assessment (e.g. a specific critical control or compliance priority)
• resources required by the assessment team, including the necessary site personnel (e.g. technical experts) that will be required to be interviewed and participate in the site inspection
• tools to be used in the assessment.

This site visit will be looking for a demonstration that:

• the range of risks to rehabilitation that have been identified
• the mine site has implemented appropriate systems, procedures and controls to facilitate sustainable rehabilitation outcomes
• systems, procedures and controls are functional in practice and effective at controlling the risks
• the workforce is competent and confident about the risk controls relevant to their area and level of responsibility
• based on monitoring, the effectiveness of controls is evaluated, and the risks are reviewed to facilitate continual improvement.

The assessment team will conclude whether, and to what extent, the mine site has demonstrated:

• compliance with legislative requirements
• how relevant components of the rehabilitation management system comply with the minimum legislative requirements
• how well the rehabilitation management and monitoring plans are being implemented
• satisfactory performance in achieving sustainable rehabilitation outcomes on the ground.

The assessment team will debrief site management on their preliminary findings at the completion of the site assessment. An assessment-finding letter and/or a notice under section 240 of the Mining Act 1992 may also be issued to the mine following completion of the site assessment.

A report providing an overview of the findings and recommendations of each of the completed TAPs will be prepared and published on our website as a learning resource.

A follow-up site inspection may also be conducted to verify:

• progress made by the mine on actioning the recommendations outlined at the initial debriefing
• progress made on addressing any matters outlined in any assessment- finding letter
• compliance with any directions outlined in a section 240 notice.