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By A Harburg, A Dendys, G Green

Dugald River Mine (DRM) is located approximately 85 km north-east of Mount Isa, and 65 km northwest of Cloncurry, in the north-west Queensland Minerals Province of Australia. DRM is an underground operation and includes an above ground processing area, a 200 ha tailings facility, two waste rock dumps and associated infrastructure. The mining method is conventional underground longhole open stoping and downhole benching of a lead/zinc deposit within a black slate environment. The deposit is estimated to contain ~53 Mt of zinc and lead, which will be mined over a 30-year period. During operations, waste rock is segregated into either Potentially Acid Forming (PAF) or Non-Acid Forming (NAF) based primarily on the sulfide concentration of the rock. In particular, the NAF waste rock is an asset and is used for various small construction projects during operation; however, its primary use is for rehabilitation work at closure. Since beginning operations in 2017, DRM has generated more NAF than was originally anticipated. Whilst this is an excellent asset to DRM, it did pose a logistical problem of where to store the additional NAF for the life-of-mine and how to manage the run-off. DRM experiences distinct wet and dry seasons with hot conditions and periods of rainfall between November to April, and relatively dry and mild conditions between May to October. Majority of rainfall is received between January and February with an annual average rainfall of 501.1 mm. Short and intense rainfall events are common. DRM’s above ground infrastructure is land-locked between two large ephemeral watercourses, making the significant expansion of any assets challenging from a permitting/regulation and cost perspective. MMG is also a member of the International Council on Mining and Metals (ICMM) and is committed to adapting to a changing climate through operations and closure. Following extensive studies DRM opted to store the additional NAF material into the adjoining NAF Dam and concurrently upgrade a previously minor sediment basin into a highly engineered sediment basin which relies on automatic flocculant dosing to meet the required discharge quality limits. This basin is climate-resilient in that the dosing system can be adjusted to counter high intensity extended rainfall events which produce highly variable inflow water quality. This abstract broadly describes how DRM designed and implemented an engineering innovation to enable the site to meet the changing climatic challenges. The abstract then describes the process to design the sediment basin and how the dosing rate was established and validated. Finally, the abstract comments on the effectiveness of the sediment basin and how it has revolutionised DRM’s approach to water treatment and management; all whilst minimising the disturbance footprint of the operation

Aug 2, 2023

By M R. Lane, M L. Cramer, N P. Wines

Increasing attention is being focused by regulators and industry on the residual environmental liabilities associated with mining projects following site relinquishment (termed surrender in Queensland). Even sites that have been rehabilitated to a high standard and to the satisfaction of the regulator are not completely risk free and may require some degree of ongoing management. As well as ongoing monitoring and maintenance costs, considerations should include how costs associated with potential risk event occurrence can be quantified and, if considered material, how provisioning should be undertaken to minimise the risk to the state and to taxpayers. In Queensland for example, once a resource site is fully rehabilitated and meets its environmental authority conditions or rehabilitation completion criteria, the tenure and environmental authority can be surrendered. During the surrender process any ‘residual risks’ resulting from the use of the site for the resource activity must be considered, and, if requested, a payment given to the government to cover any ongoing management and risk costs. Accent Environmental, in conjunction with Lane Associates, was engaged by the Queensland Government as part of the government’s financial assurance framework reforms to develop an innovative, ‘one-size fits most’ Residual Risk Calculator for the Queensland resources industry. The calculator is an Excel-based tool that uses detailed user inputs to estimate post-surrender management requirements and liability at resource sites. If residual environmental risks associated with rehabilitated mine sites can be identified, quantified and managed through pragmatic regulatory tools and effective provisioning, site relinquishment/surrender can be achieved without compromising environmental and social outcomes or exposing the state to unreasonable financial risk. The effective management of residual risk can also help facilitate operations as well as relinquishment/surrender of sites where a ‘walkaway’ solution may not be otherwise technically feasible.

Aug 2, 2023

By A Maier, M Goldner, C Gimber

Given the ongoing global crises of climate change and nature loss, with the World Economic Forum (WEF) identifying them as the top risks to global economies in terms of both likelihood and impact in the coming ten years (WEF, 2022), there is increasing, pressing demand for companies to demonstrate they understand their climate and nature related risks and look toward contributing genuine beneficial environmental outcomes. Within the mining industry, mine closure is the obvious field in which climate and nature positive strategy can be linked with operations. To do so, there is a need to challenge long-held assumptions around closure in the mining and regulatory context; particularly, to shift the focus from closing individual mines to considering regional opportunity generation and value creation.

Aug 2, 2023

By K Baker, J Purtill

One of the key challenges for the mining industry globally is the rehabilitation of mine waste, and Queensland is no exception. Out of pit waste structures including waste rock dumps and tailings storage facilities, create novel landforms which require ongoing maintenance and pose risks to the environment and sometimes to communities. Where multiple mines co-exist, such as parts of Queensland’s Bowen Basin, individual mines can often be constrained by adjoining operations. This presents opportunities for broader rehabilitation strategies to be considered, more than the current single mine focus, that may provide better environmental outcomes for a region. Given recent global disasters involving tailings storage facilities, and our team’s endeavours to drive Queensland to achieve leading practice in mined land rehabilitation, we are exploring the potential to maximise in-pit tailings disposal opportunities for coalmines through shared waste management strategies. A shared waste management strategy is where two (or more) mines, owned by different companies and operated under different environmental permits, transport tailings from one mine to the other in close proximity, for disposal in a disused pit. This would reduce the number of waste structures to be built, operated, rehabilitated, and managed in perpetuity. Our objectives are to identify and remove barriers to tailings transfers between sites to:  minimise environmental risk  minimise long-term liability of managing mining waste and associated structures  support improved outcomes for the local community. To determine the scale of coal waste disposal practices in Queensland, internal data and publicly available imagery was analysed by the Department of Environment and Science in 2022. Approximately 6500 ha of land in Queensland is utilised for coalmine tailings storage facilities or codisposal areas, with ≈ 3700 ha of this being out of pit.

Aug 2, 2023

By S Wainio, P J. Beckett, T Miller

Lichens are a symbiosis of fungi and algae. Air borne elements and gases are absorbed very efficiently over the entire surface of the lichen, because they have no protective structures such as a waxy cuticle or stomata. A survey in 1977 (one year before the Sudbury Regreening program began), indicated that several Cladonia spp had invaded the soil in Sudbury’s open birch woodlands. Pollution sensitive species such as Cladonia rangiferina and C. mitis occurred 20–25 km from the smelters. It was anticipated that the improvements in air quality and reclamation efforts would allow a natural invasion of pollution sensitive species into what once was a lichen desert that surrounded the smelters. The purpose of this project was to study the invasion of terricolous (soil-inhabiting) communities of lichens and mosses on reclaimed land in the Sudbury region 45 years after commencement of the Sudbury Regreening Program.

Aug 2, 2023

By P J. Bangerter, J Pan

Optimising for Net Present Value (NPV) with a strategic optimiser such as COMET, Prober-E, Blaser or Minemax has hitherto lacked a dynamic method for analysing the so-called third-order outcomes (such as Carbon emissions) of optimisation within life-of-mine planning. Optimisation, per se, has natural effects on carbon emissions in a life-of-mine plan. Contemporary strategic planning employs a mathematical optimiser to make sense of non-linear data (ie a block model) and produces a best-NPV optimised mining schedule, within a set of constraints. The very act of optimisation influences emissions, and in a dynamic way.

Aug 2, 2023

By S Grant, S Emeric, P Baker, E Jones, D Clark

As we strive for a sustainable and resilient future, repurposing assets has become a top priority. In Australia alone, we have a significant number of mineral projects in the pipeline, extensive existing operations, and over 50 000 legacy sites. Collectively, this presents a unique opportunity to be a world leader in mine rehabilitation. Complex stakeholder landscapes, inflexible policies, aged regulatory frameworks, technical uncertainties and increasing liabilities are all barriers hindering effective transition of legacy assets. The impetus for change is further catalysed by shifting consumer preferences, workforces in flux and regional Australians questioning what the transition means for their local community. We need innovative approaches to take a leading role in the industry and support global efforts more broadly. Co-designing an ambitious, shared vision spanning projects, operations and legacy assets with all key parties is a fundamental step to unlock and realise maximum societal, environmental, economic and reputational value. Serious play and gamification can further enhance this visioning process.

Aug 2, 2023

By N McIntyre, R Trancoso, N Bulovic

Mining is essential for facilitating human development particularly as demand for critical minerals grows. However, over the mine life cycle, the environment is permanently changed. Once mining ceases, mine-affected land can leave significant legacy issues on the surrounding environment if not managed. Therefore, mine closure planning is critical. Mine closure occurs over large scales often with the aim of recreating resilient ecosystems over mined landscapes with mitigated negative impacts. The natural state of the landscape and the environmental risks over planning time-scales are largely driven by climate. Climate change is expected to impact different parts of the post-mining landscape, from stable landform design (soil erosion mitigation) to revegetation efforts and pit lake management. Consequently, mine closure plans may need to account for a non-stationary and uncertain future climate, that may be both different to the current climate and evolve during the mine life and post-closure. Here a new data-based approach is presented for incorporating climate change projections in mine closure planning, based on the recently released Coupled Model Intercomparison Project phase 6 (CMIP6) climate data used in the latest Intergovernmental Panel on Climate Change (IPCC) assessment report. The approach: (i) characterises closure-related attributes of the future climate, and (ii) identifies the amount (and direction) of change expected to occur, and its uncertainty, focusing on five metrics for demonstrative purposes and initially describing changes in erosive potential below. This provides information on the type of future environment (ie the changing baseline) that mine closure should plan towards, and identifies rehabilitation options that may be susceptible to increased risks from climate change.

Aug 2, 2023

By C M. Côte, P Bolz, R Chrystal

The design of final landforms is an integral part of mine closure plans in Queensland and aims to ensure the rehabilitated land is safe, stable and non-polluting. Landform stability in this context is commonly assessed using Landscape Evolutions Models (LEM) which are physical models simulating sediment erosion and deposition around individual landforms over long timespans (up to thousands of years). The most used LEM for assessment of rehabilitated landforms in Queensland is SIBERIA (Willgoose, Bras and Rodriguez-Iturbe, 1991; Tucker and Hancock, 2010). SIBERIA models are complex, require very detailed input data and simulate erosion and deposition over time frames that extend decades beyond closure. They are not suitable to assess erosion risks during the operational phase of a mine and to support the development of erosion and sediment control plans. Other types of erosion models, such as the Revised Universal Soil Loss Equation (RUSLE, Wischmeier and Smith, 1978) or Water Erosion Prediction Project (WEPP, Nearing et al, 1989) calculate soil loss on a monthly or yearly basis and are much better suited to erosion management during the operational phase. They are simpler to implement and can support the design of control measures. For instance, designing a sediment basin requires quantification of sediment loads, which can be produced by these models. In Queensland, the legislation around sediment and erosion control for open cut mines is currently tightening. Soil erosion remains a major concern due to potential impacts on the receiving environment. It requires management during operation and for closure consideration alike and it is critical that erosion and sediment control plans are developed with the most appropriate tools. Globally, RUSLE is the most widely used soil loss model (Borrelli et al, 2021). This is because it is an empirical model with relatively simple input requirements: biophysical data such as soil properties, vegetation cover, topography and rainfall variability, which can be directly measured or derived from regional or national databases and/or spatial data sets that are available in most parts of the world. The second most used model is WEPP (Borrelli et al, 2021) but compared to RUSLE, there is a large drop in the frequency of its use. This is because WEPP is physically-based and has more complex data requirements. WEPP integrates hydrology, hydraulics, erosion mechanics and land cover to predict soil erosion and sediment transport on hill slope profiles and small watersheds (Stolpe, 2005). It requires some biophysical parameters in formats different from those of RUSLE, as well as detailed hydrologic and catchment data. Nevertheless, it has been used in landform design for mines across Australia to determine final landform stability (eg Howard and Roddy, 2012; Costin, 2020). In this study, we assess which tool would be the most appropriate to support development of erosion and sediment control plans from operation to closure. We use RUSLE and WEPP to predict soil loss from a mine site, compare the results from both models and outline the advantages of each method.

Aug 2, 2023

By N Patel, S Narendranathan, T Mok, J Lowe

The Hazelwood Mine (HM) commenced operations in the 1950s and was originally operated by the State Electricity Commission of Victoria (SECV) prior to it becoming privatised. ENGIE, the current owners of the Hazelwood Mine ceased operations in 2017 and have since transitioned the site into the rehabilitation and closure phase, which is to encompass a full pit lake as part of the final landform. A key aspect of HM closure is the maintenance of long-term stability of the pit slopes to deliver a final landform which is safe and sustainable, particularly given its proximity to critical public receptors. The Princes Freeway, which is the primary access route to the Latrobe Valley (LV), and the Morwell Township are both located immediately to the north of the HM. With due consideration of the mine void and nearby public receptors, the authors performed slope stability assessments of critical mine

Aug 2, 2023

By S Worden, A Lee Zhi Yi, E Sellers, G Corder, A Littleboy

The global shift towards decarbonisation is driving competition for the extraction of critical minerals such as nickel, lithium, and copper. To meet this demand, new mines are being developed while mines approaching closure are being reimagined as sites of potential resources. This reimagining challenges how mine closure is being conceptualised. In the conventional case, when a mine reaches the end of its economic life, it is closed or put into care and maintenance until it transitions to the next land use, such as agriculture, native ecosystem corridors, solar farms or integrated eco – precincts (Murphy et al, 2019; Holcombe, 2020) (the authors acknowledge that unplanned mine closures have left a devastating legacy of contamination, safety and cultural heritage impacts). Extracting minerals from closed or closing mines will extend mine life and, therefore, delay relinquishment and transition. In this context, innovative technologies are needed to make mining economically viable. In the first year of her doctoral research on improving stakeholder engagement in mine transitions, Lee Zhi Yi has coined the term ‘mine life extension technologies’ (MLETs) to describe a class of technological solutions that optimise extraction of resources after a mine reaches the end of its economic life. Examples of MLETs include agromining (van der Ent et al, 2015), in situ recovery (Robinson and Kuhar, 2018), and reprocessing or reuse of tailings (Gou, Zhou and Then, 2019). MLET extraction offers several benefits compared with conventional mining processes, such as waste remediation, value recovery of minerals, a smaller footprint and less environmental impacts (Sellers, Picorelli and Salmi, 2022). What requires further investigation is the consequences of MLET implementation to host communities or community perspectives towards the proposed technology and subsequent delays in transition.

Aug 2, 2023

By A Scrase, J Brereton

The Latrobe Valley is located approximately 150 kms east of Melbourne. Within a very small area there are 3 large brown coalmines and associated power stations, 3 large towns, and numerous smaller towns in the vicinity. The mines have been generating power for Melbourne and surrounds for the last 100 years, with two of the mines being owned and operated by the Victorian Government (State Electricity Commission of Victoria) prior to privatisation in the 1990s. All three mines were privatised with the expectation that the mine voids would be filled with water to become pit lakes, as the final landform/rehabilitation solution (Hazelwood Mine Fire Inquiry, Teague and Catford, 2016). It could be argued that until relatively recently, this was largely expected, by government and industry, to be the rehabilitation solution for managing the two key risks associated with the sites:  The geotechnical stability of the mine pits.  The prevention of fire – through covering coal batters with water. Transitioning away from mining economies requires collaborative, regional, innovative thinking with a multitude of stakeholders, from a wide range of government departments, industry, First Nations people and broader community. Closure planning and rehabilitation activities require a range of skills and experience, such as, closure planning, various scientific and engineering disciplines (pit water quality modelling, geochemical modelling, cover design, landform design, contaminated site etc), civil engineering, demolition etc. Some of these skills are similar, such as financial modelling, stakeholder engagement, contract and project management. But the majority are different to those required during the operational phase of a mine. These closure skills can also be lacking within government, with Departments more familiar with monitoring and compliance activities associated with operational facilities. Some key aspects that appear to be critical to planned successful closure are:  Collaborative regional and localised planning, with industry, government, community, First Nations and other industry, business leaders and entrepreneurs all involved in providing a smooth transition away from mining.  Well-defined and known regulatory pathways to achieve mine licence relinquishment assists in encouraging investment.  Appropriately skilled and experienced government and industry personnel.  Mining companies, who are committed to closure planning and provisioning from the earliest point in project planning.  Mine employees who are appropriately skilled and experienced in mine closure planning and implementation with access to all the relevant technical expertise required for the project. Areas like the Ruhr Valley in Germany provide good some examples of smooth processes that facilitate mine economies transition into new economies (World Resources Institute (WRI), 2021).

Aug 2, 2023

By A E. Levett, J Durbin

The environmental, social and governance (ESG) obligations of mining companies promote the consideration of water and land resources as well as the post-mining employment opportunities following the cessation of mining operations. This work aims to outline the potential for a mining operation to use their brackish mine water resources to support microalgae production, generating high-quality organic carbon sources to support their mine rehabilitation and closure outcomes. Microalgae production is an established commercial process for high-value products including vitamins, cosmetics and food supplements. On mine sites, microalgae production offers several major environmental and social opportunities: (i) carbon capture, (ii) metalliferous water treatment, (iii) acid mine drainage prevention, (iv) beneficial reuse of brackish mine water, (v) accelerated soil formation and (vi) post-mining employment (Levett et al, 2023).

Aug 2, 2023

By M Clay, J Dunlop

Thermal and metallurgical coal mining in Queensland has resulted in mines which contain voids due to open cut mining. While there are several proposals for greenfield coalmines or expansions to existing operations, many existing open cut coalmines are reaching maturity and most will leave one or more residual voids in place. The rehabilitation of mine voids is challenging. Water held in voids will evaporate over time leaving solutes to concentrate. This is likely to lead to poor water quality with limited practical use. The most basic practices to rehabilitate voids have historically involved stabilising the high and low walls, bunding to provide flood protection, and preventing public access. Regulatory reforms for mine rehabilitation were introduced in Queensland as part of the Mineral and Energy Resources (Financial Provisioning) Act 2018, and aimed to strengthen progressive rehabilitation planning, limit risks to the environment and improve outcomes for local and regional communities. Under the reforms, the goal for rehabilitation of voids is to achieve a safe, stable, and non-polluting landform, which can sustain a post-mining land use (PMLU). The reforms also introduced a requirement to describe rehabilitation of mined land in Progressive Rehabilitation and Closure (PRC) plans, replacing the description of such plans in Environmental Authorities (EAs). The reforms are not retrospective and recognise historic approvals for voids, meaning established voids will remain in the landscape as non-use management areas (NUMAs). The objectives of this study were to outline historic void rehabilitation planning practices, describe water quality limitations of Queensland mine voids and identify possible opportunities for improved planning

Aug 2, 2023

By M L, G Maddocks, A Ferrier, ers, A Forbes

Evolution’s Mount Rawdon Operation (MRO) produces gold and silver through open pit mining methods. The mining operations are scheduled to be completed in FY24 (Financial Year 2024), after which low-grade stockpiles will be processed until the end of FY27. As part of MRO’s Progressive Rehabilitation and Closure Plan (PRCP), RGS Environmental Consultants (RGS) and Deswik were engaged to develop the final landform surface and a whole of site probabilistic water balance/water quality (WB/WQ) model to evaluate the viability of several closure options with respect to water quality in the various site water storages, particularly the final void which will form a pit lake. This case study details the closure option which included (amongst other things) covering the final landforms and directing water toward or away from the final void post closure. Closure and rehabilitation for MRO had previously been planned and evaluated on a ‘domain’ basis. Furthermore, the rehabilitation plans and final water management plans for the Tailings Storage Facility (TSF), Waste Rock Storage Facility (WRSF) and other domains were not coordinated, possibly resulting in competitive rehabilitation material requirements at the commencement of closure activities. An assumption was that a legacy non-acid forming (NAF) stockpile would provide sufficient material to both supplement ex-pit material for the construction of the TSF embankment raises and to complete all closure activities, but the volumes available and the volumes required to complete the closure activities had not been quantified.

Aug 2, 2023

By G R. Hancock, W D. D P Welivitiya

is placed in a waste rock dump, which is usually later reshaped to be erosionally stable, initiate and sustain vegetation and ultimately integrate with the surrounding undisturbed landscape. However, it is unclear how this exhumed material will weather and evolve for most sites. Also, there is a lack of data on the weathering of post-mining materials. If weathering is better understood, then there is the potential to improve rehabilitation outcomes. To improve predictions of the evolution of soil properties and weathering-limited erosion, estimating the rate at which fine, transportable material is produced from the weathering of larger, non-transportable particles and the resultant fragment size distribution and how that distribution evolves over time is necessary. This study examines the weathering process for four different coalmine waste rock materials for a Bowen Basin, Queensland site. Materials obtained from various areas of the coalmine were subjected to cyclic wetting and drying and heating and cooling. Particle size distribution and other material properties were explored after each experimental cycle to ascertain how the material changes during the experimental cycles. The particle size distribution data of wet and dry cycles were used as input data in a numerical weathering model to explore the dynamics of the weathering process for each material sample. A Monte Carlo framework was employed to assess the geometry of the weathering products, weathering rate and the number of daughter particles produced within a weathering cycle. Then the SSSPAM Landscape Evolution Model was used to evaluate the influence of weathering on erosion and landscape evolution of a post mining landform. SSSPAM simulations with: (i) active weathering and (ii) without weathering were run for each material. The erosion rate and the overall landform structure were then compared between weathering and non-weathering simulations.

Aug 2, 2023

By C M. Côte, P Bolz, L Pagliero, M Edraki, M Shaygan, P Erskine

Mines in Queensland must now prepare a Progressive Rehabilitation and Closure (PRC) plan, with the requirement to justify the selection of the post-mining land use (PMLU) for each rehabilitation domain. Given that there are nearly 200 mines who must undertake a comprehensive PMLU assessment, there is a need to develop methods that will minimise the duplication of effort. As part of a broader initiative on innovative post-mining land use planning, this project undertook a regional analysis of the technical suitability of several PMLUs.

Aug 2, 2023

By T Baumgartl, A Costine, B Boshrouyeh, M Edraki

In mineral processing, the management of tailings may become increasingly more challenging with a change of ore type and the quality of water used in the plant. This, in turn, may affect the overall costs of the operation and water usage and, in the long-term, pose challenges for mine closure and rehabilitation. Depending on the applied treatment technique, the short and long-term properties of tailings are largely determined by the fine particles. Most clay materials and ultrafine particles exist in tailings from oil sands, coalmines and base metals, bringing about challenges in dewatering performance. Moreover, given the growing concern for water scarcity, the minerals industry is increasingly turning towards the use of saline water, which poses yet another challenge for tailings management. The high salt content alters the behaviour of clay particles, making dewatering a more complex process than in freshwater systems (Boshrouyeh Ghandashtani et al, 2022; Costine et al, 2018). High-density techniques for tailings management have been used for several years in the mineral industry. In this regard, one of the novel and promising dewatering methods is in-pipe or inline flocculation, where the polymer is added at high dosages to thickener underflows, giving additional (likely denser) aggregation, releasing more water on deposition compared to low solids thickening. Previous research in the field of flocculation has primarily focused on the process of flocculation itself, specifically the settling rate and size of aggregates, rather than the long-term impacts of the produced tailings materials (Liu et al, 2020; Jeldres et al, 2017). This is particularly true for the novel method of this technology, where polymer is added to the thickener underflow. Furthermore, these studies have used small-scale set-ups using buckets/beakers, plungers and mechanical stirrers for the flocculation process. Unfortunately, these methods lack the necessary control over the properties of the treated tailings, which can lead to irreproducible mixing and dispersion of viscous polymer solutions (Fawell, Costine and Grabsch, 2015). Consequently, a system that can work with a wide range of operational conditions for high-solid tailings material is essential for reliable and reproducible results. The objectives of this study were to determine the effect of different type of polymers in the presence of monovalent and divalent salts on the inline flocculation of artificial tailings. The next step was to evaluate the impact of high-dosage polymer addition on geotechnical properties such as settling rate, consolidated density, rate of consolidation and the hydraulic conductivity of tailings. In addition, this research aimed to fill a knowledge gap and investigate the feasibility of using polymer-treated tailing in removing the copper ions and then quantify the performance of produced aggregates under time-dependent processes.

Aug 2, 2023

By J Joughin, D Kyan, L Rollin

In line with the 2015 Paris Agreement and corresponding climate disclosure requirements, many mining companies have publicly disclosed that they are developing and/or implementing ambitious decarbonisation strategies. Sometimes these strategies can be linked to the development of community programs and/or the creation of a positive legacy post-closure. Renewable power is key to most decarbonisation strategies – some mines will get this from external sources and others will establish on-site power generation and storage facilities. A range of options are available to develop renewable power generation (eg solar panel, wind farm, hydropower) and energy storage (eg battery, hydrogen, pumped hydroelectricity). Land access, impact assessments, planning and environmental approvals are required to establish new facilities. Host communities are more likely to be in favour of, or at least will accommodate, new power supply developments if these are planned with a benefit to the communities. Transitioning to renewables raises new challenges. Among these are high upfront costs and access to capital, energy demand variability, supply intermittency and variability, storage limitations, grid stability and reliability, transmission and distribution infrastructure constraints. Compounding these challenges are issues such as infrastructure resilience to extreme weather events (eg heat, wind), land use and access, lengthy permitting processes, community perceptions, skilled labour requirements, and meeting mine closure objectives. Renewable energy sources provide a more decentralised source of energy that reduces reliance on imported fuels, thereby increasing energy security and lowering production costs. On the contrary, implementing renewable energy could lead to potential negative impacts such as visual perception from the community, competitive land usage, electricity price raises due to upgrading infrastructure and the use of electricity storage capacities. As part of the definition of an environmental and social management plan, participative stakeholder engagement is required to identify benefits to the communities. For example, among the recognised benefits of developing solar panels (increase job opportunities, reduce soil erosion), various technologies have been experimented globally for the last ten years and are emerging due to their proven community benefits. Key findings to enhance those benefits can range from the development of innovative practices such as ‘agri-/aqua-voltaic’, ‘solar grazing’ to optimise land usage and stimulate the local economy (Table 1), to the implementation of technologies providing services to communities such as mobile water desalination plants or ‘smart grid’ systems to minimise energy clipping during peak-load of oversized renewable energy facilities (Table 2). While developing those synergies, careful management is required to avoid creating superfluous energy service needs from community programs. Energy sufficiency should remain a key principle according to the sufficiency, efficiency and renewable framework of the Intergovernmental Panel on Climate Change. Darby and Fawcett (2018) define energy sufficiency has ‘a state in which people’s basic needs for energy services are met equitably and ecological limits are respected’. Sufficiency tackles the causes of the environmental impacts of human activities by avoiding the demand for energy and materials over the life cycle of buildings and goods. Efficiency tackles the symptoms of the environmental impacts of human activities by improving energy and material intensities. The third pillar, renewables, tackles the consequences of the environmental impacts of human activities by reducing the carbon intensity of energy supply (Cabeza et al, 2022). Life of Mine Conference 2023 | Brisbane, Australia | 2–4 August 2023 34 This paper provides project developers, decision-makers and regulatory authorities with ideas on synergies between renewable energy options and community development programs. These can be considered to enhance stakeholders’ support for implementation of decarbonisation strategies.

Aug 2, 2023

By B D. Saffron

In 1983, open cut coal mining operations were suspended at the Tent Mountain coalmine, located in Alberta, Canada in an area called Crowsnest Pass. Montem Resources (‘Montem’), an Australian mining company, purchased the asset in 2016. They conducted several drilling campaigns and undertook environmental monitoring with the intent to restart operations. In 2020, Montem completed a Definitive Feasibility Study, which indicated a mine life of more than 14 years.

Aug 2, 2023