- 3.1 Framework for Management of Acid Rock Drainage
- 3.2 Corporate Guidance
- 3.3 Sustainability and Community Considerations
- 3.4 Global Regulatory Guidance
- 3.5 Country Regulatory Guidance
- 3.6 Risk Considerations
- 3.7 References
- List of Tables
- List of Figures
3.0 Corporate, Regulatory, and Community Framework
3.1 Framework for Management of Acid Rock Drainage
This chapter examines the societal framework for development and operation of mines, and provides guidance on the ARD specific implications of the framework. This framework includes corporate, regulatory, and community elements, as illustrated in Figure 3-1 and Figure 3-2.
Every mine is established within a “community” that includes all interested and affected parties (Figure 3-2). These may include immediate neighbours, local, regional and national “communities,” and global NGOs in other countries, depending on the setting. Local communities are influential and often the most complex parties to deal with. They are the most directly affected by a mine and may have intricate needs and real and perceived rights, as described in Chapter 10.
The “community” grants and can withdraw the “social license” to operate based on perceptions of performance and the level of trust. Community needs are not always clearly defined and may change over time as socioeconomic conditions change. The operators of the mine, therefore, should remain aware of the changing environment within the community.
The issues and approaches to ARD prevention and management are the same around the world. However, the specific techniques for ARD management, for interpretation of ARD prediction results, and the quantitative endpoints for performance (e.g., water quality standards) may differ depending on the local, regional or country context.
There is, therefore, no “one size fits all” approach to address ARD management at all mine sites. Each mine setting is unique and requires a carefully considered assessment to find a management strategy within the broader corporate, regulatory, and community framework that applies to the mine. The site-specific setting comprises the social, economic, and environmental situation where the mine is located, while the framework comprises the applicable corporate and regulatory norms and standards, and community specific requirements and expectations. This framework applies over the complete life cycle of the mine and is illustrated conceptually in Figure 3-3.
Within this framework:
- All mining companies, irrespective of size, need to adhere to the national legislation and regulations of the countries where they operate. Although mining companies are not obligated to comply with global guidance unless it is a condition of funding, it is considered good corporate practice to adhere to such guidance unless it conflicts with regulations or other mandatory requirements.
- Many mining companies have established corporate guidelines that represent the company’s view of the priorities to be addressed and their interpretation of generally accepted best practice. Such guidelines provide flexibility in approach, given the site-specific nature of ARD.
- Corporate guidelines can be applied in preference to country regulations and global guidelines, provided these corporate guidelines are more comprehensive and expansive and have adopted a precautionary approach. Caution is needed to ensure all specifics of the country regulations are met, as corporate guidelines cannot be a substitute for country regulations.
- Mining companies operate within the constraints of a “social licence” that is based on a broad consensus with all stakeholders to the extent that consensus is achievable. This consensus covers a broad range of social, economic, environmental, and governance elements. ARD plays an important part in the mine’s “social licence” while at the same time stakeholders may not readily understand the associated complexity and uncertainties of ARD.
- The mine often makes commitments regarding ARD that forms the foundation of the “social licence” and should the mine fail to meet its commitments, its “social license” can be placed at risk. While ARD issues are of a highly technical nature, the consequences of “getting it wrong” should not be underestimated.
- Mining companies should make a commitment to capacity building on ARD issues within the communities where they operate. Mining companies should also solicit regular feedback and reporting on the status of ARD management plans.
- The costs of closure and post-closure management of water quality and ARD are increasingly recognized as a fundamental component of all mining operations. Provision for closure costing is now typically included in new project valuations. Some form of financial assurance (e.g., company provision, bond, letter of credit, trust fund, parental guarantee) is required in most jurisdictions. This financial assurance provides a mechanism to ensure that post-mining conditions will not leave a negative legacy that poorly reflects on mining in general and its social license to operate.
The GARD Guide provides an approach to assessment and planning for ARD management. The GARD guide also focuses on the range of procedures and methodologies that could be considered within the mine-specific setting to produce outcomes that provide an adequate level of certainty that ARD issues will be dealt with satisfactorily over the entire life cycle of the mine. A thorough understanding of the context and setting of each mine is, therefore, required before an appropriate ARD management approach is selected. This understanding requires a thorough assessment and evaluation of the applicable, social, economic, and environmental baselines. Plans, approaches, and the predicted impacts and risks need to be presented to stakeholders, and should be presented in such a way that stakeholders can evaluate the proposed performance of the ARD management plan.
While legal compliance with regional or country regulations is a minimum requirement in all instances, there are additional aspects that often add to these requirements. These additional aspects include the lenders and shareholder requirements, corporate requirements, and the local community needs.
Adequate project development, implementation resources, and time are needed to consider and integrate requirements and expectations of stakeholders. This is an important phase that is often given insufficient attention and time within the overall project timeline.
Stakeholders are increasingly better informed and more sophisticated in their understanding of ARD and ARD-related issues. The ability to deliver on commitments to manage ARD in the long term will often be scrutinised and followed, resulting in the community holding operators accountable to perform. When established, a level of trust is a valuable element of continued mine success and thus inclusiveness and transparency in actions are important for long-term performance.
The ARD management approach cannot be defined in isolation, and ARD is only one of the environmental issues (sometimes the dominant issue) that a mine must address. Problem analysis and problem solving should be integrated into the overall exploration, mine planning, construction and commissioning, operational, decommissioning, and post-closure processes, which are illustrated in Figure 3-3.
The preceding principles are discussed in more detail in the Sections 3.2 through 3.6.
3.2 Corporate Guidance
The mining industry has seen significant development in its approach to sustainability during the past 15 years. Most companies now have a public commitment to a sustainability charter, which articulates the corporate commitment to health, safety, environment, and community (HSEC). Clearly, for the mining industry, the management of ARD and prevention of adverse impacts is a core issue. Beyond the individual corporate commitments, the industry has also cooperated to develop international standards and principles for sustainable development and more specifically ARD management, notably the Mining, Minerals and Sustainable Development (MMSD) project and the International Council on Mining and Metals (ICMM) 10 Principles in the Sustainable Development Framework (ICMM, 2003). Members of the ICMM (and similar organizations) have committed to meeting these principles and to being audited against the standards set forth in these Principles.
Corporate guidance available to address ARD issues can include the following:
- Corporate charter with commitments on performance and consultation
- Commitments to external sustainability principles and metrics (e.g., ICMM and the Global Reporting Initiative [GRI])
- Public targets for environmental performance
- Specific (quantitative) performance criteria that are prescriptive
- Risk assessment protocols and methodologies to develop site-specific performance criteria, for which the methodology is prescriptive rather than the outcome
- Technical guidelines with methodologies to follow for assessment, design, and evaluation of water quality and ARD – similar to this GARD Guide. These are resource documents in which the process is prescribed, but the specific methods or criteria are not prescribed.
Corporate policies and standards differ from company to company. Selected examples of corporate guidance documentation and a perspective on how corporate requirements relate to other requirements follow in Sections 3.2.1 through 3.2.3. The corporate guidance documents that are referred to in these sections represent only a very limited cross section of the many corporate documents that are available, and have been provided here as examples of the type of corporate ARD guidance in existence. The absence of a particular company’s guidance documentation from those cited herein therefore does not imply that guidance documentation has not been developed or is not relevant. The intention here is to provide some perspective on the types and ranges of corporate guidance that exist.
Newmont has developed a guideline document titled Standard ARD Waste Rock Evaluation Methods, dated February 2003(Newmont Metallurgical Services, 2003). The guideline was developed in response to the state of Nevada’s regulations in the early 1990s. Newmont Website
The guideline document contains the following guidance:
- Protocols for ARD waste rock evaluations
- Protocols for determination of net carbonate value (NCV)
- Protocols for classification of waste types by NCV
- Protocol for NCV confirmation studies
The appendices to Newmont Metallurgical Services (2003) provide details on analytical test methodologies. The guideline is not prescriptive and can therefore be adopted within the regulatory, community, and environmental context of each Newmont mine. Newmont has integrated its ARD and metal leaching guidance into the stage-gate process for approval of capital expenditures. This method of implementation provides the discipline necessary to ensure that the appropriate level of ARD and metal leaching assessment is completed at each stage of project development.
3.2.2 Rio Tinto
Rio Tinto has developed an “environment standard” to ensure risks associated with ARD are effectively identified and managed to prevent or minimise adverse impacts and reduce long-term liabilities and costs. The standard covers all phases of mining from exploration to post-closure and covers implementation and performance measures. It also uses references to many other internal documents such as water use standards, waste management standards, and land use stewardship (Rio Tinto, 2003). In a paper titled "Design and Implementation of a Strategic Review of ARD Risk in Rio Tinto" (Richards et al., 2006), methodologies and major findings of internal reviews are summarized. These reviews were conducted by Rio Tinto as part of its ARD management programme. The purpose of the reviews was to rank hazards at its mines and to assess the performance in key management areas.
The Rio Tinto ARD management programme includes the following:
- A hazard screening protocol, which is used to identify where most of the risks posed by ARD reside within Rio Tinto. The screening protocol was designed to assess all hazards created by the release of sulphide oxidation products, including the formation of acidic soils and saline soils, the release of low pH contact waters, or the release of contact waters (i.e., waters that have contacted mining wastes) with circum-neutral pH but elevated salinity (i.e., total dissolved solids) or metals concentrations. The screening protocol ranks the potential ARD hazard posed by mining based on the physical and chemical setting of each site.
- A risk review protocol, which focuses on how each operation is managing the ARD hazards posed by the ore body and on establishing management measures to reduce the overall financial, environmental, health, and reputational risks. The review protocols are divided into 11 key performance areas that cover all aspects of successful ARD management, including baseline characterization, waste and wall rock characterization, materials management, ARD generation processes, ARD migration pathways and fluxes, potential receiving environments, integrated conceptual understanding, ARD mitigation programs, monitoring and ongoing assessment, management skills, and resources and stakeholder relationships.
The ARD management programme is not prescriptive and can therefore be adopted within the regulatory, community, and environmental context of each Rio Tinto mine.
3.2.3 Relationship to Other Requirements and Issues
The specific framework for ARD management at a particular project or mine could be defined using a hierarchy from more general, sometimes aspirational policies, to more specific site requirements, constraints, and opportunities, such as the following:
- Corporate policies, including commitments to sustainability principles (ICMM)
- Corporate standards and guidelines for environmental protection and ARD management
- Global standards and principles (e.g., World Bank and IFC Standards and Equator Principles) and best practices (as defined in this GARD Guide and other ARD guides)
- Country, provincial, or local laws and regulations
- Local communities’ needs, expectations, and aspirations
- Site conditions, including topography, climate, environmental resources, and quality
In the framework discussed above, corporate guidelines do not take precedence over legal requirements, but usually provide further clarification or expansion of the standards that the corporation will follow in addition to or in the absence of other specific requirements. In some instances, corporate guidance might be more stringent than local legal requirements and may address issues that are not covered in the applicable law. Companies following a precautionary approach may also establish additional standards of management of ARD and environmental matters in a particular jurisdiction or geographic region because of anticipated future changes in regulatory requirements.
In addition, companies are also increasingly ascribing to the principle that the practices in the ‘home’ country of the company should be considered where they are more stringent than the local requirements. Corporate governance does not discriminate environmental performance based on a geographical location. Moreover, NGOs, financing institutions, and others judge performance based on the company as whole and not on individual locations. Users of this GARD Guide should be thoroughly conversant with in-country regulatory requirements. Mining companies entering countries for the first time should be particularly careful to obtain a thorough understanding of the essence of the national, regional, and local laws before starting a new mining project.
Elements of the above hierarchy framework are discussed in more detail below in Sections 3.3 through 3.6.
3.3 Sustainability and Community Considerations
The economic benefit derived from mining is an essential contributor to sustainable development but the environmental and social consequences can offset this benefit unless managed appropriately. Appropriate ARD mitigation measures should consider the economic, social, and environmental issues on a global, regional, and local scale. Corporate and global institutional norms and national legislation and guidelines generally provide good global and regional context but sometimes fall short on local context. Local context can only be established through a thorough study and understanding of the economic, social, and biophysical baselines. Of these baselines, the social issues are the most complex and should be dealt with by effective public engagement and consultation using, where possible, local expertise knowledgeable in the customs and traditions (see Chapter 10). ARD and the associated risk are not well understood by the general public, so it is important that the mine operator invests in raising ARD-related awareness and risk communication. Communication of ARD issues is addressed in Chapter 10.
The balance that should be achieved is illustrated in Figure 3-4. The area within the triangle of Figure 3-4 illustrates a domain of results that are all acceptable. The balance point at A, which weighs the social and economic more heavily than the environmental, is equally acceptable as the point of balance at B, which weighs the environmental more heavily. The most suitable point of equilibrium can be identified only through an integrated consultative process involving all stakeholders.
Corporate guidance from multinational companies assists in imbedding sustainability considerations into projects. In addition, sustainability principles are increasingly being reflected in country regulations and processes. For example, the United Kingdom prescribes that planning should be done within the context of the regional Sustainable Development Plan. There are also a number of countries with similar whole-society development frameworks that are not specifically identified by the term “sustainability,” as well as many with spatial development, watershed, air quality, and land management plans, such as typified by catchment management plans in South Africa and regional development plans in Australia. These plans are all of relevance and should be consulted as background. Additional sources are the Environmental, Health and Safety Guidelines for Mining, published by the International Finance Corporation of the World Bank Group in December 2007 (World Bank Group, 2007) and the International Federation of Consulting Engineers (FIDIC) on project sustainability management.
Some mines can have long operational lives, so it is essential to recognize intergenerational changes in the socioeconomic needs and requirements of the affected stakeholders. ARD plans should therefore be flexible and allow for adjustment and continuous improvement over the mine life cycle (see Chapter 9). The development of the ARD management plans for a mine site should begin at an early stage in the mine development (i.e., exploration, project studies, and mine plan development). While the ultimate solution may evolve and differ at the end of the mine life when post-closure land use is selected, a plan should exist from the beginning. Technological progress will improve closure and treatment options and should be integrated into plans. With preparation of an initial plan, the final plan will require less adaptation and be simpler to implement.
Rehabilitation associated with ARD is an important factor that may determine the suitability of the land for future uses. Post-closure land use will also be dictated by factors that may include regulation, community interests, and economic needs for land. ARD prediction and management is not a precise science so long-term cost implications have uncertainty, which varies depending on the risk of ARD. These considerations should all be met while considering the overall short-term and long-term cost for the mine. Future costs are sometimes underestimated and it is therefore prudent to consider making adequate financial provisions for ARD closure and long-term maintenance.
3.4 Global Regulatory Guidance
Global guidance, by definition, can never be mandatory owing to the sovereign nature of the laws applicable to host countries. The global guidance provided by organizations such as the World Bank, International Finance Corporation (IFC) and World Health Organization (WHO), however, provides relevant and applicable standards of practice that should be taken into account for mining projects. Project funding agencies and banks have a particularly strong influence on the standards that mining companies must maintain because they frequently adopt the Equator Principles and their guidelines and standards are a prerequisite for approval and continuation of funding. The IFC Environmental, Health and Safety Guidelines for Mining (World Bank Group, 2007) provides general guidance on the prevention and control of ARD/ML, including the following:
- Design, operation, and maintenance of tailings facilities to internationally recognized standards based on a risk assessment strategy
- Preparation and implementation of ore and waste geochemical characterization, including leaching tests, ARD mapping, and the implementation of ARD preventative actions
- Rigorous impact assessments that must be implemented by suitably qualified professionals
- Mine closure planning and post-closure obligations
- Financial feasibility and closure assurance
The WHO standards identify acceptable levels of human health exposure (WHO, 2005).
Voluntary standards established by industry organisations and associations can also be of assistance, including the following:
- ICMM Principles (ICMM, 2003)
- International Cyanide Management Code (International Cyanide Management Institute [ICMI], 2006)
- Kimberley Process (Kimberley Process Certification Scheme [KPCS], 2008)
- Guidelines For Metal Leaching and Acid Rock Drainage at Mine Sites in British Columbia (Price, 1997)
- Minerals Council of Australia – Enduring Value (MCA, 2006)
- Mining Association of Canada – Towards Sustainable Mining (MAC, 2007)
3.5 Country Regulatory Guidance
3.5.1 Commonalities in the Regulatory Regimes
Most countries have environmental legislation, which is generally applicable to ARD, and some countries have specific laws, regulations, and practice guidelines that apply explicitly to ARD. In most regulatory regimes, mining proponents are required at an early stage to address potential environmental risks (including ARD) through an environmental impact study (EIS) and subsequently through environmental management plans (EMPs). EISs and EMPs are developed before the construction of a mine project. This mechanism provides the flexibility for the mining proponent to implement a management plan and environmental performance that match the mine context and that is acceptable to the regulator and affected community.
Other common themes in country legislation and regulations are as follows:
- The impact assessment process required before the issuance of an authorization or permit is generally well defined
- The environmental management plans formulated as part of the authorization process often need to describe how the effects will be managed during the mining operational phase
- The prediction of conditions and planning for mine closure
- The provision of funds for closure and post closure during the operations of the mine
- The ongoing monitoring, review, and continuous improvement, particularly for ARD
- The realization of commitments and requirements specified in permits or environmental impact assessment (EIA) approvals
A comprehensive review of specific requirements of the laws in all the countries where mining occurs is beyond the scope of this GARD Guide. The overview of some country regulatory regimes in Sections 3.5.2 through 3.5.9 provides examples of requirements and guidelines.
3.5.2 United States of America and its States
The United States has a complex regulatory system that addresses the entire range of impacts associated with all aspects of mineral development, including water and air quality, reclamation, land use, and final mine closure. While both state and federal agencies may have roles in the permitting process, state and federal regulatory agencies operate under agreements, which attempt to limit duplication and confusion in the mine permitting process.
Mining companies are subject to a combination of federal and state prescriptive standards, discharge limits, authorizations, and permits which must be obtained within a framework of spatial development frameworks and include watershed, air shed, and land development plans.
Federal laws provide a framework allowing states to implement more stringent and comprehensive laws. Often regulatory enforcement for mining, water discharge, and waste management is at the state level. Where states have primacy in mine permitting, they have developed regulatory programs that are at least as stringent as the federal requirements. These regulatory programs have been reviewed and approved by federal agencies such as the U.S. Environmental Protection Agency (USEPA) and Office of Surface Mining (OSM).
Federal laws do have specific limitations on effluent discharges and impacts on receiving water quality. Environmental impacts, reclamation obligations, and post-mining land use issues are often addressed in the environmental reviews required by state and federal laws.
Proponents of new mining projects or expansions of existing mines in the United States with the potential for ARD must comply with a series of federal and state laws and regulations that start with environmental baseline data collection and extend through the life of mine to reclamation and closure. Because of the variability of the climatic, geological, and ecological characteristics in the United States, U.S. federal regulations do not have prescriptive ARD protocols and may rely on other guidance or expertise. In many cases, state regulations have developed more specific and regional-based requirements and guidelines for ARD characterization, prediction, control designs, mitigation, and monitoring than federal regulations.
3.5.3 Canada and its Provinces and Territories
Canada consists of 10 provinces and 3 territories. The legislative authority over environmental matters is not expressly allocated to either the federal government or the provincial governments. Generally, the provinces have jurisdiction over provincial lands and matters of a purely local nature, while the federal government asserts jurisdiction over federal lands, navigable waters, nuclear regulatory matters, inter-provincial matters, and international matters. Both federal and provincial governments have produced a formidable array of legislation and supporting regulations dealing with all aspects of the environment. This section summarizes the main federal and provincial legislations and regulations that affect ARD management only and is not intended to be comprehensive of all legislation pertaining to mining or the environment in Canada. Several categories of legislation exist in Canada influencing or affecting ARD evaluation in mining. Broad categories of legislation and guidelines in Canada include the following:
- General ARD guidelines
- Securities rules and legislation for exploration and fund raising
- Closure and mine rehabilitation
- Discharge and operational limits/guidelines
- General environmental legislation
Some of the most relevant legislation, rules, and guidelines are as follows:
- Guidelines and reference materials provided under the Mine Environment Neutral Drainage (MEND) initiative
- Guidelines for Metal Leaching and Acid Rock Drainage at Mine Sites in British Columbia (Price and Errington, 1998)
- Draft Guidelines and Recommended Methods for the Prediction of Metal Leaching and Acid Rock Drainage at Mine Sites in British Columbia (Price, 1997)
- Federal Metal Mining Effluent Regulations (MMER)
- Guidelines for ARD Prediction in the North (Department of Indian and Northern Development [DIAND], 1992)
- Various provincial standards and requirements for water quality discharges
- Various provincial mine closure and financial assurance requirements for mining
Mine closure and rehabilitation guidelines and regulations in Canada are generally quite prescriptive in nature and include evaluation of all aspects of the mine, including waste rock management, tailings disposal facilities, mine and site drainage systems, mine workings, site water quality, and revegetation. The goal of the mine closure and reclamation plan is to leave the site in a condition that will require little or no long-term care and maintenance. As part of this process, it is necessary to demonstrate long-term physical and chemical stability of the materials, including an evaluation of long-term acid generation potential, metal leaching, potential water quality implications, and treatment requirements. A financial guarantee to cover the costs of reclamation must be posted by the mining company, often in the form of a bond.
Price and Errington (1998) and MEND 5.10E (2005) provide a comprehensive list of the information requirements and factors to consider regarding ARD management. The MEND 5.10E document is more concise and has more recent information on mitigation measures, whereas Price and Errington (1998) give more information on common errors, omissions, and constraints. Price (1997) outlines the proper program planning, test work and the interpretation of the resulting data. Although both Price and Errington (1998) and Price (1997) were developed to guide the mining activities in British Columbia, these documents are widely accepted across Canada, and are required methods under Ontario Regulation 240/00 under Part VII of the Ontario Mining Act relating to mine closure and rehabilitation. The DIAND (1992) Guidelines for ARD Prediction in the North identifies unique aspects of northern climate, geology, topography, and mining practices that should be considered and outlines methods for use in evaluating ARD and ML in the north.
3.5.4 Australia, its States and Territories
State and local governments in the Commonwealth of Australia have legislation and guidelines in place that are relevant to mine site ARD management. The aim of this legislation and guidelines is to protect environmental aspects such as biodiversity, water resources (quantity and quality), landforms, existing and potential future land uses, and cultural and environmental heritage.
The primary means by which state and territory governments regulate ARD is through authorisations required for a mining project. Although the regulatory regime applicable to ARD varies somewhat between jurisdictions, in general they all seek to minimise environmental impacts during operations and after operations seek to achieve sustainable landforms following rehabilitation through the minimization of pollutant release.
Key considerations under state and territory legislation include the following:
- Identification and assessment of ARD risks in the environment and social impact assessment
- Determination of financial bonds based on adequate management of ARD issues post closure
- Management of compliance with national water quality guidelines
- Availability, quality, and use of local and regional water resources
Significant “how to” guidance on the management and prediction of ARD is provided in the Leading Practice Sustainable Development Program for the Mining Industry, Managing Acid and Metalliferous Drainage (Department of Industry, Tourism, and Resources, 2007), published in February 2007 by the Australian Government, Department of Industry, Tourism, and Resources. Although they have been developed specifically for the Australian mining environment, these best practice guidelines are of value to mining companies dealing with ARD elsewhere.
Some Australian states and territories have published sustainable development plans, spatial development plans, and watershed management plans.
3.5.5 European Union (EU)
The European Commission (EC) is responsible for proposing legislation, under which the EU member states need to operate. European legislation is decided together with the European Parliament and the European Council in a so called “co-decision” procedure. Whilst some acts and regulations are put in place by the EC, each EU member state is expected to develop, manage, and incorporate its own environmental protection rules and regulations on mining.
While transposing EU directives into their own national legislation, the member states are free to include additional requirements (e.g., regulate additional substances relevant within their own territory or set higher standards). The member states are not permitted to set standards lower than EC standards because the minimum level of protection afforded should remain the same across the whole EU. According to the EU Treaty, certain areas of law, such as land-use and taxation must be regulated at the most relevant administrative level. EU mining law is therefore based mainly on national or regional laws.
A number of European environmental directives have been put in place in reference to the extractive industry. The most important of these is the Management of Waste from Extractive Industries Directive (i.e. “Mine Waste Directive”) (2006/21/EC). Prior to 2006, waste from the extractive industries fell within the scope of the Landfill of Waste Directive. However, in March 2006, the “Mine Waste Directive” was approved and is now being transposed into national legislation. This directive applies specifically to waste resulting from the extraction, treatment and storage of mineral resources, and the working of quarries. The Mine Waste Directive provides for measures, procedures, and guidance to prevent or reduce as far as possible any adverse effects on the environment, in particular water, air, soil, fauna and flora and landscape, and any resultant risks to human health, brought about as a result of the management of waste from the extractive industries.
According to the directive, no extractive waste management installation, other than certain installations containing non-hazardous waste from prospecting, inert waste, unpolluted soil, or waste resulting from peat extraction, can operate without a permit issued by the competent authorities. Member states must ensure that operators of the mining waste facility draw up a waste management plan with the objective to prevent or reduce the generation of waste and its negative impact, and to encourage waste recovery through recycling, re-use or recovery. Waste facilities may be of two types according to their potential risks: a waste facility whose failure or incorrect operation would present a significant accident hazard (category A), and all other waste facilities (not category A). For facilities in category A, the competent authority must compile an external emergency plan for the measures to be taken off-site in the event of an accident. The operator must provide a financial guarantee before the beginning of waste processing operations so as to ensure that the provisions of the Directive are complied with and that the financial resources for restoring the site are always available. A mining waste facility is regarded as finally closed when the competent authority conducts a final inspection, studies the reports submitted by the operator, confirms that the site has been restored and gives its approval. After closure, the operator must maintain and monitor the site for as long as the competent authority considers necessary. To date, five supporting decisions have been adopted by the EC to elaborate on the implementation of the Mine Waste Directive. These include the following Commission Decisions:
- Technical guidelines for the establishment of the financial guarantee (2009/335/EC)
- The definition of the criteria for the classification of waste facilities (2009/337/EC)
- The harmonisation, the regular transmission of the information and questionnaire (2009/358/EC)
- The definition of inert waste (2009/359/EC)
- The technical requirements for waste characterization (2009/360/EC)
In order to meet the requirements of this directive, waste will need to be appropriately characterized. The European Committee for Standardization or Committé Européen de Normalisation (CEN), has developed a number of standards and specifications to be published in 2012:
- Technical Report - Characterization of waste - Overall guidance document on characterization of wastes from the extractive industry
- Technical Report - Guidance on sampling of wastes from the extractive industry
- prEN 15875 “Characterization of waste – Static test for determination of acid potential and neutralisation potential of sulfidic waste”
- Technical Report - Characterization of waste – Kinetic testing for assessing acid generation potential of sulfidic waste from extractive industries
Other directives that have some relevance to ARD are discussed briefly below.
The Environmental Impact Assessment Directive (EC, 1997), requires an impact assessment to be carried out by the competent national authority for certain projects, including all mines and quarries above a prescribed size, which have a physical effect on the environment. The assessment must identify the direct and indirect potential effects of the project on the following factors: man, the fauna, the flora, the soil, water, air, the climate, the landscape, the material assets and cultural heritage, and the interaction between these various elements. The assessment is to be carried out before approval can be granted for the project; and the Directive lists the third parties to be consulted in connection with approving the project.
The Water Framework Directive (EC, 2000) is a Community framework for surface and groundwater protection and management. The Framework Directive provides for the identification of European waters and their characteristics, on the basis of individual river basin districts, and the adoption of management plans and programs of measures appropriate for each body of water. There are 6 daughter directives under the Water Framework Directive which have relevance to mine drainage – some of which set environmental quality standards for specific pollutants. In addition, EC Regulation No 166/2006 (EC, 2006b) covers the annual reporting requirements for pollutant releases to water.
The EU Environmental Liability Directive (EC, 2004b) with regard to the prevention and remedying of environmental damage includes requirements for the cost of cleanup and remediation from extractive wastes. Waste facility operators must provide a financial guarantee before the beginning of waste processing operations and must ensure that a plan and financial resources are always available for restoring the site. These plans and the financial resources must periodically be reviewed at least once every 5 years. After closure of a waste activity, the operator must maintain and monitor the site for as long as the competent authority considers necessary.
The Major Accidents Involving Dangerous Substances Directive (2003/105/EC) is based on the Seveso II Directive (96/82/EC), which focussed on protection of the environment, and covered substances considered dangerous to the environment, in particular aquatoxics. The Seveso II directive introduced new requirements relating to safety management systems, emergency plans and land-use planning, and tightened up the provisions on inspections and public information. The scope of the Seveso II directive was broadened in the Major Accidents Involving Dangerous Substances Directive to cover chemical and thermal processing of minerals extracted in mining and quarrying, related storage of dangerous substances and operational tailings disposal facilities.
A BAT (Best Available Techniques) reference document for Management of Tailings and Waste Rock in Mining Activities (EC, 2009) was adopted in January 2009.
The Integrated Pollution Prevention and Control (IPPC) Directive does not apply to the extractive industry, although some member states have applied their corresponding legislation to mines (e.g., Ireland’s national legislation covered mining before the IPPC Directive was adopted at the EU level).
3.5.6 South Africa
South African mining law requires the following of the holder of a reconnaissance permission, prospecting right, mining right, mining permit, or retention permit:
- Must consider, investigate, assess, and communicate the impact of prospecting and mining on the environment
- Must manage all environmental impacts in accordance with the environmental management plan or approved environmental management programme
- Must, as far as it is reasonably practicable, rehabilitate the environment affected by the prospecting or mining operations to its natural or predetermined state or to a land use which conforms to the generally accepted principle of sustainable development
- Must be responsible for any environmental damage, pollution or ecological degradation as a result of the reconnaissance prospecting or mining operations and which may occur inside and outside the boundaries of the area to which such right, permit or permission relates
- Must have made prescribed financial provisions for the rehabilitation or management of negative environmental impacts before the Minister approves the environmental management plan
The relevant permits relating to mining, water management, and ARD are as follows:
- A mining permit
- A water use authorisation
- An approved environmental impact assessment
In terms of ARD, the studies in support of the applications for environmental and water-related authorisations will include the following:
- The identification of all potential impacts from the mining operation
- The assessment of these potential impacts in terms of the source of the impact, potential pathways, and potential impact on the receiving water body
The South African Department of Water Affairs and Forestry (DWAF) has published a series of best practice guidelines for water management at mines (DWAF, 2006, 2007). Most of these guidelines provide guidance on pollution prevention and minimisation of impacts, and best management practice relating to general and specific mining activities that is directly applicable to ARD. A specific guideline on impact prediction which relates to ARD will be developed in 2009. These best practice guidelines offer valuable “how to” guidance on the management and prediction of ARD. Although these have been developed specifically for the South African mining environment, these guidelines may be useful to mining companies dealing with ARD elsewhere.
3.5.7 New Zealand
In New Zealand, all resource (i.e., land, air, water, and the coast) utilization is managed in accordance with the provisions of the Resource Management Act 1991 (RMA) (New Zealand Government, 1991). ARD is viewed as a contaminant which, if released into the environment, has the potential to affect natural resources. For this reason, the provisions of the RMA apply to ARD.
The release of ARD into the environment would be classified as a discharge under the RMA. Consequently, the RMA identifies the requirements for the discharge of contaminants into or onto land, air, and water.
To ascertain whether an ARD discharge requires a resource consent, it is necessary to consider the provisions of the relevant regional plan. At present, there are no national environmental standards that provide direction regarding discharges of contaminants, so only provisions of regional plans are of relevance. Given the consultative process utilised to develop documents under the RMA, each individual plan’s approach can be different even though they are all developed under the framework established by the RMA. This can mean that the type of resource consent required to undertake an ARD discharge depends entirely on which regional plan is involved.
All mineral exploitation is conducted under federal law. The Ministry of Mines and Energy (DNPM) controls and permits mining activities in the country. A mining title is the instrument granted by the federal authorities to permit exploration or exploitation of a certain mining concession. Mining activities in Brazil are, in general, subject to a set of regulations where the three levels of federal, state, and local authorities have competencies related to assessment of mining and the environment.
The National Environmental Policy regulates environmental protection and can cause action that triggers the remedy of environmental degradation resulting from a mining operation. The construction, installation, expansion, and operation of a facility that uses environmental resources, and may cause environmental degradation, are subject to an environmental licensing process that is managed by the Ministry of Environment (CRA/CEPRAM). Where mining activities are deemed to cause significant impacts to the environment (i.e., impacts to waters, soil, vegetation and air), the environmental agencies require that an EIA and environmental impact report (RIMA) be completed for the proposed mining facility.
The mining policy of Brazil includes the following principles:
- Governmental initiatives for maintenance of the ecological balance, giving special consideration to the protection of cultural heritage
- Control and monitoring the use of surface and groundwater
- Planning and supervision of the use of environmental resources
- Ecosystems protection, the conservation of special protected areas
- Control and zoning of potential or effectively polluting activities
- Incentives for the study and research of technologies aimed at environmental resources protection and use
- Monitoring of environmental quality
- Recovery or protection of degraded or threatened areas
- Environmental education at all levels, including community education, to empower the community for active participation in the defence of the environment
The Indonesian legislation related to ARD is the Decree of the State Minister of Environment No. 113 of 2003 (Government of Indonesia, 2003) regarding wastewater standards for coal mines and processing activities. The emphasis in this legislation is that wastewater standards specific to wastewater produced from coal mine activities cannot be exceeded.
The Government of Indonesia, Ministry of Environment, issued a document in 2003 containing guidelines relating to quality standard for water waste in coal mining activities This guideline prescribes the methods to prevent and handle acid rock drainage by selective placement, bacteria inhibition, soil management, revegetation, stabilization, neutralization of ARD, and handling of ARD passively.
3.6 Risk Considerations
Risk assessment is a powerful tool to develop an ARD management plan. It should be applied at each phase of mining in order to:
- Provide a logical and comprehensive basis for decision making
- Provide process transparency to government regulatory agencies and the public
- Inform decision making
- Provide input for priority setting
The risks posed by ARD/ML should be considered on a site-specific basis and the level and depth of the risk assessment should depend on the stage of mine development, hazard associated with the source of the ARD/ML, and the sensitivity of the water resource.
Risk assessment is not only a technical process and therefore the risk identification, analysis and assessment, and the selection of risk management measures should be conducted by a technical team in consultation with stakeholders. Consultation should be used to find an acceptable balance between the environmental and social and economic spheres of sustainable development. Not all risks identified may be considered ‘real’ by all parties but they should be considered equally and assessed openly if public trust is to be secured. There is likely to be more than one approach that satisfies the risk criteria in all three spheres. The selection of the preferred approach should be done in consultation with the stakeholders.
The geochemistry and risk assessment techniques related to ARD/ML for a new mine development are not as yet calibrated for all situations. There will therefore be a degree of uncertainty in terms of the confidence in the data collected and the reliability of the analysis and output. For this reason, a precautionary approach and contingency planning should be an integral part of risk assessments of ARD/ML management plans.
The level of acceptable risk will vary from the local, regional, and national communities. In addition, the level of acceptable risk changes over time. Acceptable risks today may not be acceptable in the future.
Risk is defined as the probability that a certain event (hazard) will happen multiplied by the consequence of the event (Equation 3.1).
Risk = Probability × Consequence Equation 3.1
Lee (1999) provides a risk management procedure for mine sites modified from the Management Advisory Board (MAB), Australian Public Service. Table 3-1 outlines the steps in the process. The risk assessment should be conducted by a team involving site or project staff, technical experts, or risk management specialists. The risk assessment should include the participation, or at least input, from potentially affected communities and relevant regulators.
Establish the context
Define policy, purpose, objectives, success criteria, assessment endpoints, and receptors
Identify the risk
Define sources, pathways, concerns, and consequences
Analyze the risk
Calculations (identify concerns and possible outcomes); certainty and uncertainty
Assess and prioritize risks
Compare with criteria; prioritize
Manage (treat) the risks
Mitigation, communication; develop and implement contingency and management plans
Review and monitor
Risk management plan; continue reviewing and monitoring; assess effectiveness of treatment
3.6.1 Establish the Context (Step 1)
Step 1 involves gathering information on baseline conditions, including geologic and environmental status, sites of cultural and historical interest, and rare flora and fauna. The risk assessment team determines the attitudes of local land and water users toward the mine or project and the perceived risks that it may pose. The team also collects water quality information, initiates geochemical analysis, and identifies constituents of interest (COI). At the conclusion of this step, the team should be able to identify several assessment endpoints, which will be used to guide decision making. These are explicit environmental values to be protected, which have ecological relevance and societal value, and are susceptible to chemical stressors caused by ARD. In the context of an ecological risk assessment, for example, these could include the protection of sport fishing values downstream from a mine site, that are therefore relevant to the site’s environmental management goals.
3.6.2 Identify the Risks (Step 2)
Step 2 involves the risk assessment team evaluating preliminary hypotheses about how ecological effects might occur by considering each of the potential sources of ARD, identifying transportation pathways between sources and receptors (i.e., runoff, surface water, and groundwater), formulating a comprehensive list of concerns and consequences associated with potential effects on the assessment endpoint, and estimating the level of risk associated with each effect. This step uses conceptual models of geochemical reactions and drainage transport. At the conclusion of Step 2, the team reports the following data quality objectives (DQOs): (a) define the issues; (b) describe the decisions to be made; (c) list the data inputs needed to make the decisions; and (d) outline how the data will be used in decision making. This information would be used by other project or mine planning teams in their assessments of, for example, waste rock management, open pit mining sequences, and mill tailing management.
3.6.3 Analyze the Risk (Step 3)
Step 3 involves the geochemical characterization of mine and processing units, the hydrologic characterization of flow paths, static and kinetic testing, and predictive geochemical and hydrologic modeling. The information could be used in an engineering reliability assessment of the performance of waste management or treatment schemes. In an ecological risk assessment, the data could be used to (a) define the sources of COIs, their distribution in the receiving environment, and their contact with or co-occurrence with receptors; (b) evaluate chronic and acute response relationships in the receptors (i.e., evidence of exposure); and (c) define the impact of receptor responses on assessment endpoints. Throughout this process, the risk assessment team identifies where flexibility is required to reduce uncertainty given future knowledge development. The assessment also identifies areas where risk can be reduced, and performs sensitivity analyses for various conditions and scenarios. Again this information is reviewed together with other mine planning teams so that results can be integrated into their assessments.
3.6.4 Assessment and Prioritization of Risk (Step 4)
Step 4 involves the risk assessment team estimating the technical hazards (Equation 3.1), which indicates the degree of confidence in estimates, interprets effects on assessment endpoints, estimates outcomes resulting from given consequences, and calculates overall risks. This analysis should also identify social, economic, political, and legal ramifications associated with risks, and prioritizes the risks. The results allow the team to establish the most useful monitoring programs for the assessment endpoints, which are implemented from the construction to post-closure phases. See Lee (1999) for specific methods used in qualitative and quantitative risk calculations.
3.6.5 Risk Management (Treat the Risk) (Step 5)
Step 5 involves the risk assessment team, in conjunction with other mine planning teams, identifying appropriate strategies to deal with the moderate to highest risk events. For new projects or existing mines where ARD/ML is not yet an issue, these strategies could include (a) risk reduction – reduce sources of risk or their likelihood of occurrence or both, and (b) risk avoidance – take a different course of action to avoid negative impact.
For historical mines where ARD/ML is being produced, the strategies could also include (a) impact mitigation – minimize potential impacts by designing physical and chemical barriers along flow paths and implementing contingency planning, regular audits, and internal compliance guidelines (see Chapter 6) and (b) risk co-management – identify how portions of the risk can be managed by various stakeholders including government agencies, or local communities.
In all cases, risk acceptance should be addressed: i.e., the acknowledgement that the residual risk is acceptable viewed through regulatory and sustainability lenses. At this stage, regular and adequate public consultation established with potentially affected groups can greatly reduce the risk associated with any given technical hazard, because the views of the public have influenced the decision process (MMSD, 2002).
3.6.6 Review and Monitor (Step 6)
During Step 6, the team consolidates the risk management aspects together with other project or mine teams into a risk management plan (RMP) to manage various risks from construction through post-closure phases. This plan summarizes the identification and assessment of major risks, various options for treating risks, including the benefits and costs of each option, recommended actions, the implementation plan, and descriptions of monitoring programs. The RMP should be regularly reviewed so that it becomes a living document that evolves as risks change over the mine life. The RMP will be integrated into the overall mine plan, standard operating procedures (SOPs), and environmental management systems (EMS). This is discussed further in Chapter 9.
3.6.7 Risk Priorities
The level of detail of the risk assessment and management changes as the mine progresses through the ARD/ML assessment process and the mine development stages. The initial risk assessment might be rather conceptual but will become more comprehensive during the feasibility, detailed design, and operational phases. Risk assessment and management should be specifically applied to the closure plan because of the potential long-term implications of ARD management.
Table 3-2 illustrates the relationship between the relevant ARD/ML management elements and the applicable risk management process. The last column in the table gives an example of the risk assessment tool that might be most appropriate at that stage. The application of risk assessment and risk management is discussed further in Chapter 9.
Focus Areas for Risk Management
Example Risk Assessment Tools
Potential problem assessment (PPA)
|Seepage characteristics||Assessment criteria
Particle size effect
Ecological and human health risk assessment
|Prevention||Risk management||System malfunction||Seepage characteristics
Engineering reliability analysis (e.g., FMEA)
|Treatment||Risk management||System malfunction||Effluent quality||Sample holding time
Engineering reliability analysis (e.g., FMEA)
|Monitoring||Risk management||Source characteristics
|Sample holding time
Ecological and human health risk assessment
|Performance assessment /management||Risk management
Receiving water quality
|Applicability of performance measures||
Management system audit
|Communication||Risk communication||Stakeholder views||Stakeholder acceptance||
Stakeholder mapping and surveys
|Sustainability aspects||Risk acceptance||Impacts and benefits||Environmental
Sustainability risks and opportunities assessment
- Department of Indian Affairs and Northern Development (DIAND), 1992. Guidelines for ARD Prediction in the North.
- Department of Industry, Tourism and Resources, 2007. Leading Practice Sustainable Development Program for the Mining Industry, Managing Acid and Metalliferous Drainage. Australian Government.
- Department of Water Affairs and Forestry, 2006. Best Practice Guideline G1: Storm Water Management.
- Department of Water Affairs and Forestry, 2006. Best Practice Guideline G2: Water and Salt Balances.
- Department of Water Affairs and Forestry, 2006. Best Practice Guideline G3: Water Monitoring Systems.
- Department of Water Affairs and Forestry, 2006. Best Practice Guideline H3: Water Reuse and Reclamation.
- Department of Water Affairs and Forestry, 2007. Best Practice Guideline A3: Water Management in Hydrometallurgical Plants.
- Department of Water Affairs and Forestry, 2007. Best Practice Guideline A4: Pollution Control Dams.
- Department of Water Affairs and Forestry, 2007. Best Practice Guideline H4: Water Treatment.
- European Commission, undated. Management of Tailings and Waste Rock in Mining Activities (MTWR). http://eippcb.jrc.ec.europa.eu/
- European Commission, 1997. Environmental Impact Assessment Directive (97/11/EC). http://ec.europa.eu/environment/eia/eia-legalcontext.htm
- European Commission, 2000. Water Framework Directive (2000/60/EC).
- European Commission, 2004a. Reference Document on Best Available Techniques for Management of Tailings and Waste Rock in Mining Activities. BREF Code MTWR, July. http://eippcb.jrc.ec.europa.eu/reference/
- European Commission, 2004b. Environmental Liability Directive (2004/35/EC). http://ec.europa.eu/environment/liability/index.htm
- European Commission, 2006a. Mine Waste Directive (2006/21/EC). http://ec.europa.eu/environment/waste/mining/ index.htm
- European Commission, 2006b. Regulation NO 166/2006.
- Government of Indonesia, 2003. Decree of the State Minister of Environment No. 113.
- International Council on Mining and Metals (ICMM), 2003. http://www.icmm.com/our-work/sustainable-development-framework/10-principles
- International Cyanide Management Institute (ICMI), 2006. International Cyanide Management Code For The Manufacture, Transport and Use of Cyanide In The Production of Gold (Cyanide Code). http://www.cyanidecode.org/
- Kimberley Process Certification Scheme (KPCS), 2008. http://www.kimberleyprocess.com/home/index_en.html
- Lee, M., 1999. Risk Assessment Framework for the Management of Sulphidic Mine Wastes. Australian Centre for Mining Environmental Research (ACMER), September.
- Mine Environment Neutral Drainage (MEND), 2005. List of Potential Information Requirements in Metal Leaching/Acid Rock Drainage (ML/ARD) Assessment and Mitigation Work. MEND Report 5.10E.
- Minerals Council of Australia (MCA), 2006. Enduring Value - the Australian Minerals Industry Framework for Sustainable Development. http://www.minerals.org.au/enduringvalue
- Mining Association of Canada (MAC), 2007. Towards Sustainable Mining. http://www.mining.ca/site/tsmprogressreport2011/index.html
- Mining, Minerals & Sustainable Development Project (MMSD), 2002. http://www.iied.org/sustainable-markets/key-issues/business-and-sustainable-development/mining-minerals-and-sustainable-development
- Newmont Metallurgical Services, 2003. Newmont, Standard ARD Waste Rock Evaluation Methods. February 20, Englewood, CO.
- New Zealand Government, 1991. Resource Management Act (RMA). Ministry for the Environment.
- Price, W.A., 1997. Draft Guidelines and Recommended Methods for the Prediction of Metal Leaching and Acid rock Drainage at Mine sites in British Columbia. British Columbia Ministry of Employment and Investment, April.
- Price, W.A., and J.C. Errington, 1998. Guidelines for Metal Leaching and Acid Rock Drainage at Mine sites in British Columbia. Ministry of Energy and Mines, August.
- Richards, D.G., Borden, R.K., David, J.W., Blowes, D.W., Logsdon, M.J., Miller, S.D., Slater, S., Smith, L., and G.W. Wilson, 2006. Design and Implementation of a Strategic Review of ARD Risk at Rio Tinto. In: R.I. Barnhisel (Ed.), Proceedings 7th International Conference on Acid Rock Drainage (ICARD), March 26-30, St. Louis, MO, American Society of Mining and Reclamation (ASMR), Lexington, KY.
- World Bank Group, 2007. Environmental, Health and Safety Guidelines for Mining. International Finance Corporation (IFC), December.
- World Health Organization (WHO), 2005. International Health Regulations.
List of Tables
- Table 3-1 : Risk Management Procedure for Mine Sites (modified from Lee, 1999)
- Table 3-2: Integrating Risk Approach into ARD/ML Management
List of Figures
- Figure 3-1: Framework for ARD management
- Figure 3-2: Hierarchical relationship between Global, National and Local Elements of the Framework
- Figure 3-3: Conceptual ARD Management Framework
- Figure 3-4: Sustainable Development Balance