Environmental and Closure Costs in Strategic Mine Planning, Models, Regulations, and Policies

Abstract

This study explores the evolution of mine planning, with particular emphasis on the integration of environmental and social factors in alignment with the sustainable development. Traditionally, mine planning emphasized technical and economic variables, often overlooking environmental and social impacts. However, the increasing need to align with the Sustainable Development Goals (SDGs) has prompted a shift toward broader definitions that incorporate these factors into resource planning. This paradigm change is crucial for managing risks related to project profitability, which now include environmental considerations. The article also examines how government policies and corporate strategies, including Corporate Social Responsibility (CSR) and Environmental, Social, and Governance (ESG) frameworks have evolved to address these impacts. A review of the literature published over the last 25 years identifies four main thematic areas: (1) inclusion of environmental costs in mine planning, (2) quantitative models for calculating environmental and closure costs, (3) legal frameworks in mining, and (4) innovations in public policies. This study underscores the need for a comprehensive approach in mine planning that balances economic, social, and environmental considerations to ensure sustainability and mitigate risks associated with mine closure and environmental remediation.

1. Introduction

Mine planning, like the mining industry as a whole, has undergone significant evolution over the past decades. It is now evident that there is a paradigm shift in the conception of a mineral deposit, aligning with SDGs established at the Rio de Janeiro Summit [1] and reaffirmed in the 2030 Agenda of the United Nations [2]. Traditionally, the classical definition of a mineral deposit focused on maximizing economic profitability by considering a limited set of technical variables that directly influenced financial indicators. These variables primarily addressed geological factors such as the genesis and morphology of mineralization, geomechanics, concentrations, and the distribution of the ore body, among others [3]. However, environmental and social factors were often overlooked or treated as externalities.

The necessity of meeting the SDGs (as shown in Figure 1) and overcoming environmental and social challenges has led to new definitions that better reflect the realities of extractive and mining projects [4]. These definitions encompass not only the previously mentioned variables but also the environmental, ecological, and socio-economic factors faced by mining projects. Consequently, mineral resources and reserves are now directly influenced by these factors, which were historically considered external to technical planning.

Strategic mine planning plays a critical role in managing uncertainties associated with projects to mitigate risks in the calculations of Net Present Value (NPV) and Internal Rate of Return (IRR) [5,6]. Environmental factors carry associated risks that must be addressed in alignment with the interests and needs of the state, the mining company, and local communities [7]. Premature project termination poses a significant risk to sustainability, often resulting in higher closure costs compared to well-planned or ongoing closure efforts [8]. This underscores the importance of considering and adequately planning these activities from the project’s inception or early stages [9].

Mining companies must comply with environmental and social standards dictated by the legal frameworks of the jurisdictions where their projects are located. Governments have approached the challenge of sustainable extractive industry development through various strategies tailored to their historical, economic, and environmental contexts [10]. These strategies include taxation, centralized mining authorities, and regulatory measures to oversee the industry.

Examples of such regulations include mine rehabilitation and recovery obligations, environmental compensation payments, and the procurement of mining–environmental insurance policies to cover unanticipated impacts [11]. Despite these measures, many projects encounter environmental and social challenges, necessitating the implementation or enhancement of Corporate Social Responsibility (CSR) campaigns and Environment, Social, and Governance (ESG) frameworks [12,13].

Strategic planning, particularly corporate policies adopted by mining companies, has evolved alongside the extractive sector [14]. In response to operational challenges, companies have introduced sustainability and corporate social development policies driven by corporate values and voluntary initiatives [15,16]. While international and national regulations mandate environmental and mine closure standards, many companies strive to exceed these requirements [17]. These initiatives help prevent negative impacts and potential conflicts among stakeholders (company, state, and communities) [18] or alleviate existing tensions in ongoing projects, such as disputes over land, mineral, or water use.

Although environmental and social factors have been considered in operational planning, they have not been integrated directly into block models and are treated as externalities or accounting liabilities incurred at the end of a mine’s life. This approach often leads to cost overruns, as remediation efforts are generally more expensive than early mitigation [19,20]. Evaluating, quantifying, and incorporating impacts enables companies to anticipate the costs of repair and mitigation and provides a foundation for economically comparing the environmental and social advantages and disadvantages of mining projects [21,22].

Environmental impact assessments are mandatory for any project. However, when complemented with additional methodologies and mining designs, they can serve as essential tools for achieving a social, environmental, and economic balance. These methodologies suggest mechanisms that facilitate the implementation of control and preventive measures [23,24]. Identifying potential impacts in advance allows for informed decision-making regarding intervention strategies and opens opportunities to evaluate alternative mining methods [25,26].

Despite the mandatory nature of environmental considerations, holistic project planning remains inadequate [27]. While many studies have explored global and regional economic analyses related to mineral depletion, detailed engineering and designs for sustainable resource management require further development [28,29]. Incorporating these variables could not only improve environmental and social performance [30] but also yield economic and commercial benefits for companies, warranting greater attention.

This study aims to review the most relevant research and contributions in this area, allowing readers to identify promising trends or strategies that can be integrated and improved by companies or governments to enhance the environmental performance of the mining sector and its operations. Using the ScienceDirect and Springer databases, key works published between 2000 and late 2024 were identified through searches using terms such as “environmental costs in mining”, “quantification of environmental costs in mining”, “mine planning and environment”, “mine planning and mine closure”, “public policies in mining”, “mine closure legislation”, and “public policies and extractive industry.” Finally, we used the ChatGPT-4 tool to improve the writing style and translation of the text. The analysis identified four main themes for a comprehensive literature review: (1) inclusion of environmental costs in mine planning, (2) quantitative models or methodologies for calculating environmental and closure costs, (3) legal frameworks for mining in selected countries, and (4) innovation in public policies adopted by specific administrations.

The existing literature includes numerous studies examining the environmental or social impacts of mining activities worldwide, describing and quantifying liabilities and proposing strategies to improve environmental performance in specific processes. Examples include substituting chemical compounds with organic substances in metallurgical processes and using technologies to reduce CO₂ emissions. However, such studies are outside the scope of this review, which focuses on the inclusion of environmental and mine closure variables. Additionally, this study does not address the qualification or identification of negative mining impacts, detailed mine closure projects, or CSR initiatives in specific cases.

2. Inclusion of Environmental Costs in Mine Planning

As previously mentioned, the mine planning process has also evolved to optimize environmentally friendly practices. Although research in this area is not as extensive as studies on cut-off grade optimization, the inclusion of geomechanical variables, metallurgical optimization, risk management associated with mineral prices, or geological uncertainty, among others [6,31,32,33,34,35,36,37,38,39], there is a growing body of work focusing on incorporating environmental, mine closure, or social factors into mine planning.

Given that a significant portion of environmental costs stem directly from waste generated during mineral exploitation and processing, Osanloo et al. [40] proposed a methodology to reduce such waste by optimizing the cut-off grade for porphyry deposits. Adrien Rimélé et al. [41] optimized the Net Present Value (NPV) and Life of Mine (LoM), incorporating variables aimed at minimizing tailings in a copper operation. Their mathematical formulation integrated geological uncertainty and aimed to define the optimal sequence of block extraction, categorizing blocks as reserves or waste for disposal.

Kumral [42] utilized Simulated Annealing to minimize the amount of tailings and waste generated in mine production plans. This mathematical model introduced flexibility in extraction rates, leveraging feedback from mined blocks to estimate waste from future blocks, enabling short-term profitability projections while meeting production requirements. Seredkin et al. [43] reformulated mineral processing techniques for certain deposits, drawing from the success of in situ recovery in uranium extraction. According to the authors, this method enhances both environmental and economic performance by eliminating the need for material removal, processing, and waste disposal, thus avoiding many conventional costs. Other studies addressed environmental concerns through unconventional planning algorithms: Adiansyah et al. [44] tackled tailing management and treatment, while [45,46,47] focused on minimizing CO₂ emissions or air pollutants. These efforts used multi-objective optimization functions for decision-making in block sequencing operations. Li et al., Ullah et al., Anderson & Razaie [48,49,50] explored alternatives to optimize projects by minimizing the production of acid mine drainage. However, these studies typically addressed specific parameters rather than providing a comprehensive integration of environmental variables.

Holistic approaches to environmental factors in mining include X. C. Xu et al. [51], who proposed a detailed methodology for calculating ecological costs—accounting for over 40 parameters—associated with a polymetallic project. These costs were internalized within a 2D optimization algorithm that conducted iterative simulations to create a final 3D envelope. Adibi et al. [26] calculated ultimate pit limits (UPLs) and qualitatively evaluated environmental, social, and mine closure factors to select the pit with the best performance and economic relationship using multi-attribute decision-making techniques. Similarly, Moradi and Osanloo [52] addressed 77 sustainability indicators present in mining projects, providing a qualitative assessment that quantified and weighted each criterion. Narrei and Osanloo [53] optimized the cut-off grade using Lane’s traditional algorithm [54] while incorporating mine closure costs and potential future income from productive activities in the project area. Rahimi and Ghasemzadeh [55] employed the same algorithm but included environmental costs from various metallurgical methods. In both cases, costs were assumed rather than calculated.

Assuming it is more beneficial for a company to extend the operational life of a project by extracting and processing low-grade ore, Nehring and Cheng [56] selected a 2D optimal pit with the highest NPV among calculated pushbacks. They proposed seven scenarios extending the mine life from 10 to 17 years while respecting mining and processing constraints. Closure costs were calculated for each scenario using Australia’s “Asset Retirement Obligation Estimates” methodology [57]. The study concluded that extending LoM by four years increased mineral recovery, offset closure costs, and enhanced NPV.

Paricheh and Osanloo [58] modified Hutchison’s [59] approach to estimate mine closure costs, using Monte Carlo simulation and decision tree analysis to probabilistically estimate closure costs and LoM. They generated 2D block models and final pits with a 100% price occurrence probability, creating additional pits for positive price scenarios. Closure costs for these pits were calculated following X. C. Xu et al. [51].

Rahmanpour and Osanloo [60] determined several final pits and calculated their associated NPVs. Environmental performance was measured using Impact Factors (IFs)—e.g., land use, mineral recovery, alignment with local development plans—and Environmental Components (ECs)—e.g., safety, community relations, air and water quality. These factors were analyzed through matrix methods. However, the methodology relied on expert judgment, introducing subjectivity in determining indicator magnitudes. X. Xu et al. [61] applied a case study where the selected optimal pit was associated with higher environmental costs compared to pushbacks. Factoring in restoration costs and the economic value of ecosystem services—such as land opportunity costs and carbon emissions—revealed other scenarios with superior economic outcomes.

Expanding on these findings, X. Chuan Xu et al. [62] applied their methodology to a real polymetallic mine. They demonstrated that integrating calculated costs into the block model produced a scenario with 2.5% higher NPV, despite initially appearing less favorable. Notably, this research focused on block sequencing rather than ultimate pits.

Jafarpour and Khatami [63] employed expert valuation systems to weigh environmental costs in mining projects. These valuations were adjusted through coefficients across seven scenarios sequenced using dynamic system-based software. However, this study did not quantify environmental costs. Meanwhile, Badakhshan et al. [64] developed a mixed-integer programming model to maximize NPV by incorporating mitigation, prevention, and compensation costs for transitioning from open-pit to block-caving mining. These costs were derived from expert input and international guidelines but lacked specific calculation methodologies.

Liu et al. [65] presented an innovative perspective by incorporating mine closure planning from early project stages. They proposed designing a UPL that includes future revenues from building a small hydropower plant (SHP) within the mined-out pit. Although challenging to replicate due to unique case study characteristics, this approach offers promising alternatives for planning sustainable and productive mine closures.

Table 1. Summary table of environmental or mine closure cost research in mine planning.

Reference	Year	Minerals	Partial or Total Inclusion of Variables	Parameters Included		Application
				Environmental Costs	Closure Costs	Open-Pit Project	Underground Project
[40]	2008	Copper	Partial (acid drainage)	✓		✓
[42]	2013	Gold	Partial (tailings)	✓		✓
[44]	2014	Polymetallic	Partial (tailings)	✓		✓
[45]	2014	Coal	Partial (CO2)	✓		✓
[51]	2014	Polymetallic	Total	✓	✓	✓
[26]	2015	Copper	Total	✓		✓
[52]	2015	-	Total	✓		✓
[53]	2015	Iron	Partial (tailings)		✓	✓
[55]	2015	Copper	Total	✓		✓
[43]	2016	Uranium	Partial (process)	✓		✓
[56]	2016	Copper	Total		✓	✓
[46]	2016	Coal	Partial (CO2)	✓		✓
[58]	2017	Copper	Total		✓	✓
[60]	2017	Copper	Total	✓		✓
[61]	2017	Not specified	Total	✓		✓
[41]	2018	Not specified	Partial (waste)	✓		✓
[62]	2018	Polymetallic	Total	✓	✓	✓
[49]	2020	Polymetallic	Partial (acid drainage)	✓		✓
[63]	2021	Copper	Partial	✓	✓	✓
[50]	2023	Copper	Partial (ESG)	✓			✓
[64]	2024	Copper	Total	✓		✓	✓
[65]	2024	Iron	Total	✓	✓	✓
[47]	2024	Coal	Partial (CO2)	✓		✓

summarizes the reviewed studies, categorizing them by publication year, included variables (environmental or closure), and project type.

The studies analyzed in this section share a common need to quantify environmental or mine closure aspects. Some employ qualitative methods, subsequently evaluated to establish indices, others use methodologies or equations to quantify costs, and some simply assume economic values to integrate them into sequencing, scheduling, or ultimate pit calculations. It is noteworthy that few studies focus on underground mining projects, and no research specifically addressing mining clusters or districts in this area was identified. In the following Section 3, the most prominent works aimed at quantifying costs associated with environmental variables in mining projects are discussed.

3. Quantitative Approaches for the Evaluation of Environmental and Mine Closure Costs

In the literature on quantitative models or methodologies for calculating environmental and mine closure costs, three significant subgroups can be identified. The first subgroup comprises studies that propose equations for calculating environmental costs (primarily academic or research works). The second subgroup involves methodologies for calculating closure costs, particularly regulatory frameworks from various countries and strategies developed by private companies. The third subgroup includes methodologies that, while not directly quantifying costs, propose quantitative models to evaluate the environmental performance of mining projects through the creation of indices. For brevity and clarity, we will highlight the most relevant works and explain the most comprehensive methodology from each of these groups.

The economic valuation of environmental variables has been extensively studied in engineering projects. Various methodologies exist that allow the quantification of these variables in monetary terms. From a legislative perspective, some countries have implemented regulations requiring a thorough and guided valuation of costs associated with closure and abandonment activities, as is the case in Chile, certain U.S. states, and Australia. However, considering the nature and magnitude of the impacts caused by mining projects, there remains a gap in research and information on the quantification of environmental costs specific to this field. Proper valuation of these aspects would not only help determine the investments required to mitigate, prevent, and remediate potential impacts [66] but could also offer new approaches to comprehensive economic evaluation and project feasibility analyses [67] and assess the profitability for a nation in pursuing projects of this nature [68].

Ex-post evaluations of case studies suggest that the closure costs calculated at the end of operations are generally higher than those incurred through progressive closures [69]. Environmental impact assessments must be integrated with these closure plans, which should also be included in mine planning throughout the entire life of the mine [70,71] [72]. Research has proposed methodologies for calculating rehabilitation costs in areas affected by illegal or irregular mining activities. These studies are based on the costs of individual tasks required for the proper recovery of such areas [73,74,75] and the intended future use of the recovered land. However, these methodologies fall short of anticipating impacts and advocating for progressive closures that enhance both environmental and economic performance.

Geographic Information Systems (GISs) provide a valuable alternative for understanding and monitoring the outcomes of progressive closures. These systems supply information on the condition of affected areas and serve as tools for mine planning by providing area-based data that can be integrated into the planning process [76,77]. Furthermore, the costs associated with these systems are typically related to production rates, extraction scales, and the dimensions and areas of operations [78].

From a sustainable development perspective, it is crucial to conduct economic evaluations of productive projects planned for post-closure operations and to outline the necessary transitions [79,80]. Documented cases in some studies reveal that post-closure productive activities for open-pit coal mining projects often include agriculture (over 50% of cases), forestry projects (17% to 96%), and aquatic recreation (9% to 26%) [81]. Additionally, some researchers suggest that the highest costs are associated with open-pit operations, followed by waste dumps and industrial facilities. The lowest costs, albeit not insignificant, are those near waste dumps and pits that are indirectly affected [82].

Among the noteworthy works, Kosinskiy et al. [83] proposed a methodology for environmental economic analysis based on the loss of Gross Regional Product (GRP), including labor time lost due to negative environmental impacts. Delgado and Romero [84] analyzed environmental conflicts using an integrated method of gray clustering and entropy weighting (the IGCEW method). Field data, gathered through interviews, indicated that conflicts are more likely to arise from issues such as access to potable water, poverty, GDP per capita, and employment. The IGCEW method employs weighting functions to rank observation indices perceived by different stakeholders, making it highly applicable to the analysis of environmental conflicts. Gulley [85] addressed costs related to mercury discharge in various countries, caused either indirectly (e.g., mercury sulfide emissions from mineral deposits) or directly (e.g., illegal or small-scale metallurgical recovery methods), and calculated costs per ton for each scenario.

Narrei and Ataee-pour [86] proposed the choice experiment method (based on stated preference approaches), which was used to survey individuals affected by mining operations about their perceptions of the project and the monthly costs they would be willing to bear to achieve high, medium, or low environmental, social, and economic outcomes. Five possible scenarios were presented, from which respondents had to choose one based on their perceptions. The results indicated that affected individuals believe the company should pay an additional USD 11.3 per extracted ton. Vergara et al. & Kitula [87,88] employed the contingent valuation method (CVM) to estimate the costs that those impacted by mining projects felt they should receive annually as compensation for lost environmental services. This method estimates the value of non-market goods by simulating a market through consumer surveys—in this case, the population affected by mining operations [89]. Vergara Tamayo et al. [87] found that residents were willing to receive approximately USD 1,500 annually for the implementation of the project.

According to Badakhshan et al. [64], six factors influence the environmental costs of mining: the Human Development Index (HDI), mining scale, proximity to populated areas, mining type, mineral type, and the ecosystem where the project is located. By consulting experts and drawing from the authors’ experiences, they established costs per ton for open-pit and block-caving projects. Similarly, Rodríguez-Zapata et al. [90] conducted a contingent valuation using surveys among residents of a mining district with five open-pit coal projects. Although this study aligns with research using contingent valuation to determine environmental costs, it stands out for focusing on a mining district or cluster rather than a single project.

Gu et al. [91] proposed a methodology for calculating total environmental and ecological costs through simple summations. They argued that environmental costs result from the combined damages to an ecosystem’s functions and the restoration value of these functions. Their first measurement, the ecological footprint, links local resource demand (in this case, mineral resources) to the regenerative capacity of the soils where mining activities occur. Considering the variety of soil types and environmental impacts within a mining project, their approach incorporates impact types, soil types, and contamination levels in each area.

While the aforementioned works provide valuable approaches for estimating environmental and mine closure costs, the most precise and deterministic methodologies are those proposed by X. C. Xu et al. [51] and by Chile’s National Geology and Mining Service [92]. These methodologies will be discussed in Section 3.1 and Section 3.2, respectively.

3.1. Quantification Methodology for Environmental and Ecological Costs in Mining

Although this methodology has not been expanded or modified by other researchers, it has been widely used by various authors to develop works related to mine planning and the economic quantification of environmental variables. The methodology proposed by X. C. Xu et al. [51] involves optimizing the design of the final pit while considering the quantification of ecological costs. The calculations used to define these costs include four main components related to the type and area of soil impacted by mining. These components are the following: (i) loss of the ecological value of direct services, (ii) loss of the ecological value of indirect services, (iii) prevention and repair costs, and (iv) ecological costs of carbon emissions due to energy consumption.

The parameters suggested by X. C. Xu et al. for estimating environmental and ecological costs take the following into account: value lost from direct eco-services, $C_d$; value lost from indirect eco-services, $C_i$; and CO₂ emission costs, $C_{pr}$. These equations are presented in detail below, from Equation (1) to Equation (7):

$$V_s={\displaystyle \frac{s v}{{10}^4{\rho }_s{h}_m}}$$

(1)

where $s$ is the soil retention capacity, ${\rho }_s$ is the soil density, $h_m$ is the soil thickness minimum for cultivation, and $v$ is the annual net income from local crop cultivation.

$$V_a={\displaystyle \frac{1.62 q}{f_c}}{c}_C+y_s{c}_s+y_d{c}_d$$

(2)

where $q$ is the net primary productivity, $f_c$ is the carbon (C) to (CO₂) mass conversion factor, $c_C$ is the cost of carbon capture and storage, $y_s$ is the forest capacity to absorb SO₂, $c_s$ is the SO₂ removal and control cost, $y_d$ is the forest capacity to absorb dust, and $c_d$ is the dust removal and control cost.

$$V_o=1.2 q c_o$$

(3)

where $q$ is the net primary productivity, $c_o$ is the cost f oxygen production, and 1,2 corresponds to the oxygen release factor.

$$V_r=10 p k f_r c_r$$

(4)

where $p$ is the average precipitation, $k$ is the proportion of rain causing runoff, $f_r$ is the runoff reduction coefficient caused by the forest, and $c_r$ is the cost of storing water in a reservoir.

$$V_n=q (k_N{P}_N+f_p{k}_p{P}_p+k_K{P}_K)$$

(5)

where $q$ is the net primary productivity, $k_N$ is the nitrogen content in the soil, $P_N$ is the nitrogen fertilizer cost, $f_p$ is the phosphorus mass conversion factor to P₂O₅, $k_p$ is the phosphorus content in the soil, $P_p$ is the phosphorus fertilizer cost, $k_K$ is the potassium content in the soil, and $P_K$ is the potassium fertilizer cost.

The value of the total lost indirect ecological services ($C_i$) is calculated by considering the time period from soil and vegetation removal to complete restoration:

$$C_i=\left({\displaystyle \frac{Q_o}{P_o}}+N\right)\left(V_s{+V}_a{+V}_o+V_n+V_r\right)$$

(6)

where $Q_o$ is the ore in the pit, $P_o$ is the annual ore extracted, and $N$ is the period from removal to soil recovery.

$$C_{pr}={\displaystyle \frac{(e_d{f}_d+e_g{f}_g+e_e{ba}_c{f}_c)c_C}{1000}}$$

(7)

where $e_d$ is the average diesel consumption per ton of material removed, $f_d$ is the carbon emission factor for diesel, $e_g$ is the average gasoline consumption per ton of material removed, $f_g$ is the carbon emission factor for gasoline, $e_e$ is the average electricity consumption per unit mass of extracted material, $b$ is the proportion of total electricity generated from coal, $a_c$ is the amount of thermal coal required to generate one unit of electricity, $f_c$ is the carbon emission factor for coal, and $c_C$ is the cost of carbon capture and storage.

To determine the total ecological costs, a simple summation of $C_d$, $C_i,$ and $C_{pr}$ is developed, which represents what a company should invest as compensation for direct and indirect ecosystem services and CO₂ emissions to the atmosphere. In this example, the $C_d$ variable is not presented because it is exclusively dependent on the yields that a productive project of another type (e.g., livestock, agriculture, aquaculture, etc.) can have in the area where the project is located. This methodology does not calculate closure and abandonment costs, and therefore, the next section will present this information.

3.2. Methodology for Calculating Mine Closure Costs (Servicio Nacional de Geología y Minería Sernageomin)

This regulation allows for addressing mining regulation with a strategic planning approach, sustainability, and financial guarantees that do not exist in other countries, and it also provides a point of comparison and reference for other legislations that still lack a detailed framework for calculating these guarantees. Law 20.551 [92] regulates mine closure and the associated costs. This methodology proposes a series of calculations to determine an exact value that mining projects must allocate for mine abandonment in Chile. The methodology includes the following: (i) direct closure costs, (ii) indirect closure costs, (iii) administrative costs, (iv) contingency costs, and (v) the 19% value-added tax (VAT). To develop this methodology, it is essential to accurately know the characteristics and cubic measurements of the project, as all economic values are based on these factors. In order to summarize what is outlined in Law 20.551 and make it more accessible to the reader, Figure 2 was created, presenting its methodological sequence in a condensed form and explaining the components of each stage:

The costs considered in the total calculation of the closure plan value are calculated based on reference rates (units of account, or UF in this case) and also take into account data from closure plan values within the mining industry. Since each closure case has its own specific characteristics, corrections are made to values associated with the geographical location, altitude above sea level, and distance to supply centers. The unit of account (UF) is a Chilean monetary unit created to adjust commercial and accounting transactions in line with inflation. Regarding the measurement of cubic volumes, these can be developed using the values presented by Valdebenito [93], which relate the reference rate (UF) to the units of measurement for each work or installation.

According to these reference values, the UF investment required varies depending on the type of infrastructure or mining component. For example, decommissioning steel and concrete structures involves costs of approximately 15 UF per ton and 12 UF per square meter, respectively. Larger-scale interventions, such as closure of sterile dumps and tailing deposits, require significantly higher investments, reaching several hundred UF per hectare. Leachate management stands out as one of the most costly elements, exceeding 2600 UF per hectare. Additionally, environmental recovery measures, including revegetation, soil remediation, and hazardous waste disposal, range from 0.3 UF per square meter to 8 UF per cubic meter, depending on the specific intervention required. For a more comprehensive understanding of these measurement units, we suggest that the reader refer to the work of Valdebenito [39], cited in this paper.

For the correction factors shown in stages 5, 6, and 7 of Figure 2, Valdebenito suggests that the geographical correction factor in the Chilean case varies between 0.91 and 1.0 depending on the region and that the altitude correction factor is 1.0 for operations below 3000 m above sea level, 1.25 for operations between 3000 and 4000 m above sea level, and 1.45 for operations above 4000 m above sea level. It is also recommended to use the correction factor for supply centers $F_p$ based on the distance from the mining operation to the nearest urban perimeter of the supply center x using the Equation (8) shown below:

$$F_p=e^{0.0014x} if 0<x<650 \mathrm{k}\mathrm{m}$$

(8)

$$F_p=2.5 if 650 \mathrm{k}\mathrm{m}\le x$$

The methodology of this law focuses solely on quantifying the closure costs that mining companies must assume in Chile. However, it does not address the quantification of environmental compensation throughout the life of the mine, nor does it evaluate the environmental performance of operations during the extraction and operational stages of projects. For this reason, in the following section, we will present some sustainability indicators that allow for these performance evaluations.

3.3. Sustainability Indices in Mining—APH Method

The global impact of mining activities is very difficult to measure. Most companies use indices such as the Global Reporting Initiative (GRI) [94], specifically the GRI 14 for the mining sector. However, although it serves to make a detailed qualitative analysis of all the impacts of a project, it does not provide quantitative analysis tools [95]. The majority of these studies share the common denominator of using discrete Multi-Criteria Decision-Making (MCDM) methods, which allow for quantitative evaluation through subjective assessments (mostly expert opinions) to achieve qualitative results [96]. Two of the most commonly used methods are the TOPSIS method (Technique for Order of Preference by Similarity to Ideal Solution) [97] and the Analytic Hierarchy Process (AHP) [98]; however, it is also common to see research proposing a hybrid use of both methods.

Kosinskiy et al. [83], in addition to proposing a method to calculate the Gross Domestic Product (GDP) of a territory, create an indicator that directly relates the change in the GDP of a mining region, the amount of CO₂ emissions, the amount of waste produced, and the average days of medical incapacity per person with other indicators of quality of life, such as increased birth rates, mortality rates, and life expectancy.

There are few studies proposing indices to assess sustainability in the mining industry and even fewer that focus on quantifying both positive and negative impacts. Dialga [96] constructs a sustainability index for the mining industry (MISI), which is part of a relationship between the value of mining companies in the country and government social investment in specific fields. This indicator is very difficult to replicate as it involves factors that differ by country (legislation, investment forms, allocation and nature of resources derived from mining activities, levels of corruption, etc.). On the other hand, based on six indicators and twenty-five sub-indicators rated by three experts, Jiskani et al., [99] design a sustainability index that serves to assess the sustainable performance of an operation and the desired level it should have. Based on their findings and an AHP diffusion process, they evaluate and assign a specific weight to each criterion evaluated (on a scale of 1 to 5).

Varouchakis et al. [100] correlate a water resource availability index (including aquifers) with the intensity of mining activities in Europe. However, it does not encompass sustainability in a global manner. Galo et al. [25] develop an index to evaluate the level of preparedness of mining companies for the mine closure phase; this index is built by evaluating four dimensions (legal documents submitted for mine closure, physical and chemical stability in situ, company costs and financial provisions, and community participation in the productive transition), performed by experts in three mines in Brazil. Based on a TOPSIS method from Hosseinpour et al. [101], they propose a semi-quantitative model for the comprehensive assessment of the sustainable performance of a mining project. They include 22 parameters for positive impacts and 21 for negative impacts directly related to the concept of sustainable development. Bascompta et al. [14] propose an index to evaluate Corporate Social Responsibility (CSR) of mining companies, addressing 30 impacts of a mining project (20 positive and 10 negative), grouped into the environmental and socio-economic dimensions. Each impact is assigned a value from 1 to 5 based on expert evaluation. The index has a result range from 0 to 100, within which the performance of the company’s CSR policies can be defined. It is worth noting that this index is quite user-friendly for evaluators.

Y. Li et al. [102] develop an index based on the DEMATEL method (a MCDM method) [103,104], in which they assess eight environmental impacts, six economic impacts, and six social impacts specifically for the case of mining in China. With this method, the authors aim to prioritize impacts to allow decision-makers in mining companies to focus on compensating the most critical impacts. Bascompta et al. [105] correlate the economic growth indicators of 45 mining companies in Europe (medium- and large-scale mining) with CSR indices. It is demonstrated that there is a strong correlation between industrial growth improvement in economic terms and the enhancement of CSR performance. Finally, Heydari and Osanloo [106] propose the quantitative evaluation of 99 factors affecting the sustainable development of mining projects. A specific weight evaluation is performed for each of these factors to determine which are the most influential. A novel aspect of this research is that it includes two very important aspects in the environmental impact assessment (also included in Environmental Impact Matrices [107,108]): the temporal and geographical scales of each impact. This work uses various MCDM methods, such as DEMATEL and Fuzzy analysis.

For practicality and the scope of this review, we will only explain the AHP method and its mathematical formulation. This method decomposes a problem that involves many variables by providing a qualitative description of them, establishes an order of importance, and numerically values each one to prioritize the variables. Below, we will explain the process to develop the AHP method in three stages.

3.3.1. Stage 1

The process begins with a set of criteria or attributes that are treated as ordered pairs to construct a matrix to which values (ranging from 1 to 9) are assigned based on expert opinions. This matrix $\left[M\right]$ contains the pairwise comparisons of the criteria to which values have been assigned, where

$${\left[M\right]}_{m\times n}=\left[\begin{array}{cccc}{a}_{11}& a_{1j}& ..& a_{1n}\\ a_{i1}& a_{ij}& ..& a_{in}\\ :& :& :& :\\ a_{m1}& a_{mj}& ..& a_{mn}\end{array}\right]donde i=1,\dots ,m; j=1,\dots ,n$$

Additionally, to comply with the criterion of reciprocal judgments, the following must be satisfied: if the importance of criterion $\left(i\right)$ relative to criterion ($j$) is given by ${(a}_{ij})$, then the importance of criterion ($j$) relative to criterion $i$ is ${1/(a}_{ij})$. When $\left(i\right)$ equals ($j$), the value assigned will be 1. In the case of comparing the same criteria against each other to create a ranking, $\left(m\right)$ will equal ($n$), resulting in a square matrix.

3.3.2. Stage 2

In this stage, it is necessary to perform a synthesis of the variables. This is conducted by calculating the eigenvalues and eigenvectors of the computed matrix. A normalized matrix $\left[P\right]$, or total proportion matrix, must be created. To do this, the values in each column of the matrix are summed, and each element is divided by the total of its respective column, as follows:

$$[P]={\displaystyle \frac{\left[M\right]}{\sum _{i=1}^n{a}_i}}\mathrm{that} \mathrm{is} \mathrm{to} \mathrm{say}, {\left[P\right]}_{m\times n}=\left[\begin{array}{cccc}{\displaystyle \raisebox{1ex}{$a_{11}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}& {\displaystyle \raisebox{1ex}{$a_{1j}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}& ..& {\displaystyle \raisebox{1ex}{$a_{1n}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}\\ {\displaystyle \raisebox{1ex}{$a_{i1}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}& {\displaystyle \raisebox{1ex}{$a_{ij}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}& ..& {\displaystyle \raisebox{1ex}{$a_{in}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}\\ :& :& :& :\\ {\displaystyle \raisebox{1ex}{$a_{m1}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}& {\displaystyle \raisebox{1ex}{$a_{mj}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}& ..& {\displaystyle \raisebox{1ex}{$a_{mn}$}\!\left/ \!\raisebox{-1ex}{$\sum a_i$}\right.}\end{array}\right]$$

To finalize this stage, it is necessary to average the rows of the matrix $\left[P\right]$ to determine a priority vector $\underset{\left[V_P\right]}{\to }$, in which the ranking of importance among the variables can be identified.

3.3.3. Stage 3

In order to evaluate the reliability of the matrix and the prioritization performed, the product of each element of the weighted matrix ([M]) must be summed, multiplied by the priority calculated for the corresponding criterion. This results in a vector, which should be divided by the weighted sum of the priority of its corresponding criterion [109]. The mean value λ_max of the previous result must be determined, and a consistency index (IC) for each criterion must be calculated using the following formula:

$\mathrm{I}\mathrm{C}={\displaystyle \frac{{\lambda }_{max}-n}{n-1}},$ where $n$ corresponds to the number of criteria evaluated.

Subsequently, a random index (IA) is determined, following the formula below:

$$\mathrm{I}\mathrm{A}={\displaystyle \frac{1.98(n-2)}{n}}$$

Finally, the consistency ratio (CR) must be established as follows:

$\mathrm{C}\mathrm{R}={\displaystyle \frac{\mathrm{I}\mathrm{C}}{\mathrm{I}\mathrm{A}}}$, if CR < 0.1 the index is acceptable; otherwise, the initial rating given by the experts must be re-evaluated.

After presenting the main research and works that provide methodologies for the quantification of environmental or mine closure costs, it is necessary to delve deeper into the legal requirements that mining companies face in certain countries, as environmental performance and obligations are not the same for all. In Section 3, Legal Frameworks, we will address the legislation governing mining companies in eight countries and their fiscal burden, which is closely related to the compensation paid for the development of a mining project.

4. Legal Frameworks

In order to address sustainability in the mining industry, particularly in the area of mine closure and the quantification of these costs, it is necessary to have a clear overview of the legal frameworks of several countries to identify where the main advancements are taking place and what the positive and negative experiences have been in the application of these public policies in each territory [109,110]. Mining or extractive legislation can be analyzed from different perspectives: occupational safety and health, required permits, classification of mining, payment of royalties or taxes, mine closure, environmental protection, the institutional structure of mining authorities, and policies for informal mining, among others. This article reviews mining regulations regarding mine closure and discusses the fiscal burden implemented as compensation or tax for the mining sector, since generally parts of these revenues are destined for reinvestment in matters of sustainability and development of the countries. A selection of Latin American countries that stand out for their mineral extraction rates, two European countries (governed by the European Union legal framework but with national modifications), and one leading country from North America and Oceania known for being mining powerhouses are analyzed.

It is important to clarify that there is no international regulation suggesting a model for implementing mine closure programs or policies [111,112]. However, some studies, such as the one proposed by Porter [113], have served as guides for establishing stricter regulations that improve business performance while reducing environmental liabilities generated by mining projects [114], and other international standards such the ISO 21795-1:2021 serve to guide closure efforts toward proper recovery of sites affected by mining [115]. Legal frameworks could increase the environmental and economic returns for companies but may also lead to greater challenges if they are not proposed and executed correctly [116]. Therefore, the role of governments should focus, among other things, on contributing to the sustainable development of the mining industry without compromising employment or tax revenues from the sector, providing solid governance, and reducing social and environmental impacts [117,118].

All mining projects must comply with a closure and abandonment plan that meets the standards required by the legislation of the country where it is implemented. Framed in the theory of sustainable livelihoods (MVS) or the Sustainable Livelihoods Framework (SLF) [119], a closure plan can be defined as the restoration of ecosystem services provided to the affected communities through economic activities after the completion of the extractive activity [120,121]. This means that globally, operations have different ways of internalizing such plans, the environmental standards required are not uniform across the industry, and there are significant differences in the conditions that governments set for the development of mining activities [122,123]. Thus, there are large differences in the level of requirements companies face to carry out abandonment tasks, as well as the monetary amounts they must incur [23].

We can assert that mine closure processes have evolved positively, and three temporal stages can be identified. The first stage is characterized by environmental liabilities, as companies were not obliged to carry out rehabilitation work, or the requirements were minimal, meaning the government had to bear the costs of rehabilitation and environmental quality improvement at the end of the project life. The second stage is marked by the emergence of international treaties and the birth of the sustainable development concept. In this stage, extractive projects are governed by stricter regulations than before, and companies are required to incur costs related to the rehabilitation of impacts generated by their operations and provide a closure plan to be fulfilled. Despite this, it has been evidenced that the legislation still has legal gaps that prevent, among other aspects, the establishment of clear methodologies for calculating the economic costs of closure and the timelines for these investments. The third stage, currently emerging, focuses on the planning of mining projects with holistic designs that include, in addition to traditional parameters (geological, market, technical, etc.), aspects of closure, social, and environmental factors.

In the area of mine closure, it is pertinent to classify the methods and strategies found in the state of the art. The first relates to various studies in which mining companies consider closure-related variables in innovative ways, which are beyond the scope of this paper. The second concerns the legal and regulatory framework that governs these activities and the requirements established by each country to execute and calculate the investments that should be made. It is important to briefly mention some current regulations, identifying the legal requirements and economic obligations that must be fulfilled in each case.

4.1. Chile

In order to establish a methodology to estimate closure costs in mining operations, the National Geological and Mining Service of Chile—SERNAGEOMIN, developed Law 20.551 Servicio Nacional de Geología y Minería Sernageomin [93], which provides a valuation guide where the costs considered in the total closure plan value are calculated based on cubic measurements of works, tasks, and project infrastructure, with each being multiplied by monetary factors in units of promotion (UF). This regulation is one of the most complete and detailed in Latin America, clearly establishing the costs that mining concessionaires must assume. Regarding fiscal contributions to mining projects, there are three rates that companies must pay: a value-added tax (VAT) on profits, an operational income tax, and an ad valorem tax. These payments range between 0% and 46.5% of the operational income of the companies [124,125].

4.2. Peru

Law No. 28,090 [126] mandates an obligatory financial guarantee, which is established from the beginning of mining projects and must be renewed annually. Initially, a total cost for executing the mine closure plan is established, and each year, the amount invested in progressive closure tasks and the previous year’s paid guarantees is deducted. Finally, to determine the amount to be paid for the year in question, it is divided by the remaining useful life of the project. It is important to note that the methodology used by this law promotes early and progressive mine closure.

From a tax perspective, companies are required to pay up to 34.6% as the total tax burden, including income tax, royalties, the Special Mining Tax (IEM), and the Special Mining Levy (GEM) [127,128].

4.3. Colombia

In Colombia, Law 685 (Código de Minas) [129] suggests the use of Mining Environmental Guidelines for executing and designing all mining activities, including closure plans. While it qualitatively describes the tasks and works to be carried out, it does not establish methodologies for calculating the monetary investment. An environmental mining insurance policy must be taken out annually, which acts as a warranty in the event of non-compliance with environmental regulations.

Regarding the payment of royalties or taxes, mining companies are required to pay an income tax (derived from profits obtained from exploitation) and additionally must pay royalties that go into a centralized common fund managed and invested in the regions. The total tax burden can reach up to 70%.

4.4. Bolivia

Bolivia’s legal framework has undergone significant changes in recent years. In fact, it was only in 2009 that a new Mining Law was established, declaring mineral resources as public assets without the possibility of purchase (as it was previously). Since then, the rules have changed, and projects are now considered public–private, where the concessionaire is a partner and investor in mining projects [130]. Currently, the Mining and Metallurgy Law of 2014 [131] and the Environmental Regulation for Mining Activities of 1997 [132] provide guidelines for closure tasks, but they are somewhat vague and lack a clear methodology for calculating the required investment.

As for royalties and taxes, it is important to clarify that taxes can reach up to 37.5% of the total profits recorded from the projects, plus a maximum of 5% of the total recorded income [133].

4.5. Canada

While there is a legal framework governing the entire country, as in all federal or similar models, the Canadian provinces have more freedom to define their own mining and taxation policies. The Canadian Mining Certification Program establishes an integrated approach for mine closure, which involves active participation from social groups. It also requires concessionaires to present a financial guarantee ensuring funds are available to carry out closure tasks once a project is finished [133].

Tax rates in Canada depend on the province where the project takes place. For instance, in British Columbia, the total tax rate only reaches 23% based on the company’s income, there are no royalties, and everything is taxed under the income tax model [127,128].

4.6. Spain

Directive 2006/21/EC [134] establishes criteria for the closure and abandonment of hazardous mine waste deposits within the European Union. It requires mining concessionaires to submit technical reports and closure plans detailing investments to be made. National state entities approve or disapprove these plans or reach agreements with companies [135]. It is worth noting that Autonomous Communities in each region have the authority to monitor and supervise mining projects. In Catalonia, for example, the Directorate General for Energy, Mines, and Industrial Safety [136] sets the value of the bonds covering mine closure and rehabilitation of areas affected by mining [137].

In terms of taxation, Spain does not have a royalty payment policy. All mining companies must pay the Corporate Tax, which taxes company profits at 25%, and a VAT (21%). Additionally, Autonomous Communities can decide whether to charge an extra tax on mining activities. In Catalonia, for instance, this surcharge is between 1% and 3% of the mineral sales, making the total tax burden approximately 48% [138].

4.7. Sweden

In Sweden, the Mineral Ordinance [139] focuses on risk management and a rigorous follow-up to ensure compliance with requirements for mine restoration and closure. Mining companies must make a bond payment at the start of the project, which is agreed upon between the company, the state, and impacted communities. This bond must cover the total cost of remediation and mine closure tasks. It is important to mention that the state receives and manages these resources.

Regarding the fiscal burden of mining projects, it is necessary to clarify that there are no royalties, and from a tax perspective, mining is considered just another business. However, tax rates in Scandinavian countries are among the highest in the OECD [140], with Sweden’s tax rate at 29%. The only additional fee mining companies pay is 0.02% of total sales, which is allocated to a fund for mining research, innovation, and compensation for landowners affected by the project [141].

4.8. Australia

As in the United States, Australia delegates the responsibility for legislating and regulating mine closure to each of its states. Two prominent regulatory frameworks are those of Western Australia (WA) [142] and Queensland [143]. In WA, a cost calculator is used to estimate the responsibility and annual levy payable into the WA Mine Rehabilitation Fund. In Queensland, another cost calculator was developed to determine the basis for the financial guarantee to be paid. The literature includes studies using both calculators for the same case, finding similar calculated amounts [80].

Likewise, the total tax burdens for mining projects depend on the state where the project takes place. In Northern Territory, for example, a constant rate of 18% is paid as royalty, while in other states, it varies depending on commodity value, type, and amount extracted. In Western Australia, it can reach a maximum of 52% of total income [127,128].

As mentioned, while there is common concern for mine rehabilitation and closure, some regulatory frameworks are more rigorous in determining costs related to this process. This not only increases the environmental risks associated with the projects but also suggests that social pressures may increase in the future due to lax regulations that do not promote early or correct investment in environmental impact control [144]. On the other hand, having legal methodologies for calculating environmental costs helps reduce the approval or denial times of permits for the implementation of projects. When clear and concise guidelines are established for evaluating closure plans and their costs, it is possible to eliminate bureaucratic negotiation processes between state entities and companies.

Table 2. Comparative table of methodologies to calculate closure costs, tax burden, royalty payments, and level of centralization of the mining sector.

Country	Law	Methodology for Calculating Closure Costs	Maximum Tax Burden	Royalties Payment	Management Level
Chile	Ley 20.551, 2014	✓	47%	✓	Central
Peru	Ley N°28090, 2003	✘	35%	✓	Central
Colombia	Ley 685, 2001	✘	70%	✓	Central
Bolivia	Ley Minería y Metalurgia, 2014	✘	43%	✓	Central
Canada (BC) *	RSBC, 1996	✘	23%	✘	Federal
Spain (Cat) *	Decret Legislatiu 14/1994	✘	48%	✘	Autonomous **
Sweden	Mineral Ordinance, 1992	✘	29%	✘	State domain
Australia (WA) *	Mining Act, 978	✓	52%	✓	State domain

* BC: British Columbia; Cat: Catalonia; WA: Western Australia; ** Autonomous corresponds to Autonomous Community (CCAA), equivalent at the state level.

below summarizes the fiscal burden, closure cost methodologies used in each country, and whether royalties are paid as a result of mineral exploitation. It also mentions the level of governmental centralization in the mining sector in each country.

5. Innovation in Public Policies Adopted by Some Governments

In recent years, the extractive sector has posed one of the greatest challenges in terms of public policy for countries that generate part of their fiscal revenue from the development of this activity. The growing demand for mineral resources, driven by the transition to renewable energy, technological development, and demographic growth, has intensified the need for innovative public policies that integrate sustainability into mining practices [145,146].

Beyond the commitments made by companies to achieve environmentally friendly and socially sustainable projects, the responsibility for ensuring a sustainable mining sector falls on the states, as they are the ones responsible for setting the rules of the game [147]. Many of the objectives established in international climate agreements (signed by countries) aim at stricter industrial activity regulations, including the mining sector [148]. Although countries are part of these treaties, it is common for them not to modify their regulations, often maintaining a more extractive approach that moves away from sustainability [149,150]. As a result, research efforts have focused on the development of subnational or local policies that allow for the design of tailored strategies depending on the characteristics and needs of each territory [151]. Some countries have opted to restrict mining projects in specific areas to preserve and conserve ecosystems, such as the cases of Argentina and Chile with glaciers or Colombia with páramos [152]. However, such decisions are sometimes driven more by political motivations than by technical or scientific foundations.

Traditional regulatory approaches have often been insufficient to address the complexity of current challenges, leading to a search for adaptive and participatory models [68]. The implementation of clean technologies and the adoption of responsible mining practices require regulatory frameworks that integrate environmental and social criteria from planning to execution [153]. Innovation in public policies can provide more flexible regulatory frameworks that facilitate the implementation of these technologies and practices necessary to achieve better economic, social, and environmental outcomes.

Based on the definition of sustainable development, it is essential to have active community participation in decision-making for economic growth in their territories [154]. This may present challenges due to the lack of technical knowledge in certain areas, especially in rural areas with conditions such as limited access to education, healthcare, and employment opportunities [146,155]. Despite this, as [156] suggest in their case study in Poland, urban or rural zoning tools and planning instruments can serve as a starting point for residents to directly influence future land use before and after mining projects. In these cases, achieving collaborative development among all stakeholders requires starting from principles of reciprocity [13].

One of the most successful cases documented is in northern Finland, where, as a solution to the question of socially responsible mining, social management plans (SIMPs) have been proposed, in which communities actively participate in decision-making and collaborative planning of the mining project. Involved companies can learn to understand the issues that may generate social conflicts if not addressed, local administrations can use them to plan services and infrastructure, and local residents can use them as a channel to express their interests and ideas [157]. The SIMP was successful in Finland and was established as a public policy for mining activities that are in the feasibility stages in the country. However, in other parts of the world, new environmental conflicts persist, where there are no agreements between communities and companies on how to achieve sustainable project development [158].

Part of the strategies employed by public administrations focus on incentives and disincentives for the development of mining projects. This can be a double-edged sword, as increasing the fiscal burden could deter investment in the sector (especially harmful for commodity-dependent countries) [159], while decreasing it may result in diminished governance credibility and increased risks of environmental and community pressures in case production levels rise and auditing institutions are unprepared [155]. The tax issue remains complex, not only due to the revenue models (whether a royalty model exists, taxes are levied on income or profits, etc.) [160], but also because of its redistribution across different levels of public administration and society. In China, for example, a fiscal policy change was implemented in 2017, which, in addition to giving local administrations greater involvement in revenue collection, introduced a reform on mining company taxation with ad valorem taxes and automatic fiscal adjustment mechanisms [161]. In 2017, another proposed change in the Chinese government was the implementation of the “Action Plan for Soil Pollution Prevention and Control” (APSPPC), which introduced punitive measures, not only economically through fines but also by affecting companies’ credit reports and lowering their credit ratings for non-compliance with regulations [162], representing significant pressure for mining companies, especially those listed on the stock exchange or on the verge of obtaining loans.

In addition to the challenges posed by sustainable mining development in recent years, new issues have emerged that were not previously addressed. Pepper et al. [163] examine public policies governing the care and maintenance of mines that have not yet closed but had to temporarily suspend operations due to exogenous factors like market conditions. If they have not closed but are not in the production stage, how is sustainability guaranteed during this period? They identify legal gaps [164] and suggest possible solutions, such as requiring progressive closures and periodically recalculating closure bonds and guarantees considering already closed areas, environmental performance indicators, and the companies’ economic performance.

The increase in technological capabilities and the rise of technocratic models have become essential for better understanding projects, conducting proper monitoring, and negotiating project terms. Public administrations’ adoption of new technologies and tools enables more accurate data and figures necessary for decision-making and tax imposition [165]. The use of drones to assess stocks, progress, and the size of rehabilitated and intervened areas may be a good option [166]; however, it requires significant investment in equipment acquisition and professional training. Despite the high costs, studies suggest that stronger institutional capacity is crucial for building credibility, enhancing environmental performance, and ensuring effective tax collection and reinvestment from companies [167]. This could also be a key factor in avoiding or falling into economic problems like the “resource curse” [168]. Policies like those outlined in the previous section (Section 4) in countries such as Sweden or Colombia are important for promoting best practices in the extractive industry, especially in mining, where a small percentage of fiscal revenues is reinvested in science, technology, and innovation for the mining sector, fostering increased interest and tools for environmental optimization and more environmentally friendly processes within the industry [10].

Vertical integration and the decentralization of entities responsible for overseeing, controlling, collecting, and sanctioning the mining industry are additional factors that correlate with better sustainable mining practices [169]. Numerous studies have focused on deepening the relationship between governance models in which local or state authorities play an active role and better environmental outcomes in mining territories (districts, states, autonomous communities, departments, etc.) [170,171,172,173,174,175,176,177,178]. These studies demonstrate that decentralizing financial powers and giving local governments (environmental and mining authorities) a more prominent role can positively impact local economic development and control the primary risks faced by territories due to mining activities [179,180]. The implementation of mixed governance models that employ technocracy and agency models may be an important step for nations still lagging behind centralized models [181]. However, research on such organizational reforms in public institutions is scarce and outdated, and there is also a lack of political will to implement them.

Toward Global Approaches?

The mining industry stands at a sustainability crossroads, where it must balance the enhancement of social and environmental outcomes with the economic viability of projects, all within a unified regulatory and methodological framework [182]. While previous research has highlighted the complexity of designing a universally accepted method for quantifying environmental and closure costs in mining, the question remains whether a consensus can be reached to standardize these calculations [183]. Public sector initiatives across various countries demonstrate that regulatory advancements and adaptive governance are converging toward similar objectives [184]; however, significant disparities persist among nations with varying degrees of economic dependence on mining and differing social contexts [185,186].

One of the main challenges in developing a universal model lies in the heterogeneity of mining operations worldwide. Geological conditions, extraction technologies, regulatory frameworks, and socio-economic contexts vary significantly across regions, making the establishment of a one-size-fits-all methodology impractical [187]. Nevertheless, efforts to harmonize environmental impact assessments and closure cost calculations are gaining momentum, particularly through international standards and the creation of financial assurance mechanisms in countries with mature and developed mining sectors [188]. These examples suggest that while full standardization may not be feasible, a structured framework with adaptable parameters could help bridge the gap between local regulations and global best practices [189].

From a public policy perspective, achieving consensus within the industry requires not only regulatory alignment but also financial and technological incentives that promote the adoption of sustainable practices by companies. Integrating environmental costs into financial models—through risk-adjusted project valuations and progressive closure bonds—could serve as a stepping stone toward broader acceptance of sustainability-driven mine planning [190]. In this regard, governments play a critical role in facilitating collaboration among industry stakeholders, enforcing stricter environmental accountability, and funding research to improve cost estimation methodologies. Moreover, the role of countries that demand these raw materials is equally crucial, as downstream industries can drive responsible sourcing decisions by prioritizing suppliers that meet high sustainability standards [191].

The feasibility of a universally accepted approach also hinges on the political will of nations to prioritize long-term environmental stewardship over short-term economic gains [192]. While some countries have adopted decentralized governance models to enhance oversight and public participation, others continue to operate under extractivist policies that hinder sustainable transitions [185]. Lessons from Finland’s Social Impact Management Plans (SIMPs) illustrate how participatory governance can mitigate conflicts and establish more resilient regulatory frameworks, potentially serving as a reference for broader adoption in other regions [12]. Although a fully standardized global methodology for calculating environmental and closure costs in mining may remain an elusive goal, progress can be achieved through incremental regulatory convergence, cross-border collaboration, and the adoption of flexible yet comprehensive frameworks. The future of the mining industry, from a public policy perspective, will depend on the ability of states to balance resource exploitation with sustainability imperatives, ensuring that mining activities contribute to economic development without compromising environmental and social well-being.

6. Conclusions

The evolution of mine planning has led to a holistic approach that not only considers economic profitability but also environmental and social aspects, aligning with the SDGs. In response to the growing demand for sustainable processes, strategic planning has become an essential tool to mitigate risks associated with negative impacts and ensure the long-term viability of projects. The inclusion of environmental costs and the implementation of Corporate Social Responsibility policies are crucial to balancing the interests of businesses, communities, and governments. Despite progress, gaps in holistic planning persist, highlighting the need to effectively incorporate environmental variables into mining models and strengthen regulation and public policies to achieve truly sustainable development in the sector.

While most research has focused on maximizing traditional economic indicators, such as Net Present Value (NPV) and cut-off grades, methodologies that incorporate environmental and mine closure costs into optimization algorithms are being explored [58,63]. This approach not only mitigates the negative impact of mining activities but also improves long-term profitability by considering sustainability from the early stages of the project. As the industry moves toward more responsible practices, it is essential to continue developing and implementing strategies that comprehensively assess the costs and benefits associated with mining, ensuring a more balanced development that benefits businesses, communities, and the environment.

There are quantitative methodologies applied in mining to calculate environmental and closure costs, with three main approaches standing out: equations for environmental costs, regulatory frameworks for closure costs, and environmental performance evaluation models. While regulatory frameworks exist in countries like Chile, the U.S., and Australia, methodologies for quantifying environmental costs in mining remain limited. Proper valuation could improve the profitability and sustainability of these projects. Additionally, methodologies such as Geographic Information Systems (GISs) for monitoring progressive closures and multi-criteria methods like AHP and TOPSIS are useful for creating sustainability indices. More comprehensive models include the quantification of ecological impacts, considering the loss of environmental services and carbon emissions, along with specific methodologies, such as the Chilean SERNAGEOMIN regulations, which calculate closure costs based on reference rates and correction factors. These methodologies are crucial for responsible mining and for making informed decisions about the costs derived from environmental impacts and the economic sustainability of mining operations.

While there is no international standard for mine closure, countries like Chile and Australia have advanced legislation that requires financial guarantees and calculation methodologies to ensure the environmental and social restoration of affected areas. The experiences of countries such as Canada, Sweden, and Australia highlight the value of clear regulations that allow for greater collaboration between governments, businesses, and communities to mitigate environmental impacts and facilitate the transition of land use in mining-affected areas. As evidenced in this review, in addition to many research studies or methodologies originating from these countries, the EJAtlas—Global Atlas of Environmental Justice [193] records show a higher concentration of conflicts in countries with lax or unclear legislation. The comparison suggests that stricter regulations not only benefit the environment and communities but also reduce the risk of social conflicts by ensuring that companies assume financial responsibility from the early stages of the project. Differences in fiscal burdens and royalty policies reflect the diversity of approaches to sustainability in mining. However, it is evident that having well-defined closure costs and methodologies improves the permitting process, the economic evaluation of projects by state entities, and transparency in the mining sector, promoting a balance between economic development and environmental responsibility.

Innovation in public policies for the extractive sector is crucial to addressing contemporary challenges related to environmental and social sustainability. With the growing demand for mineral resources, countries must adopt more stringent legal approaches while being flexible and participatory in processes involving local communities in decision-making. The implementation of regulatory frameworks that integrate environmental and social criteria from planning to execution is key to achieving sustainable development. Successful cases, such as the social management model in Finland, demonstrate that community participation can reduce conflicts and foster more harmonious development. However, the challenge of balancing fiscal incentives and disincentives, along with the need for technological capacities and institutional robustness, highlights the complexity of governance in the mining sector. To avoid falling into the resource curse, it is essential for states to modernize and innovate their regulatory frameworks, prioritize decentralization, and promote reinvestment in science and technology, ensuring the responsible and sustainable management of mineral resources.