Landslide Risk: Systematic Approaches to Assessment and Management

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MINE 425 MINE CLOSURE AND RECLAMATION In
structor Assoc. Prof. Dr. Sebnem
Düzgün Room304 duzgun_at_metu.edu.tr
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CHAPTER 1 PRINCIPLES OF MINE CLOSURE

• OUTLINE
• 1.1. Introduction
• 1.2. Time span of mine closure
• 1.3. Factors to be considered
• 1.4. Mine closure planning
• 1.5. Activities of mine closure
• 1.6. Stakeholders of mine closure
• 1.7. Legislation and regulations
• 1.8. Social impacts
• 1.9. Financial aspects

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1.1 Introduction

• All mining activities has an end due to
• ?exploitation of the ore reserves
• or
• ?uneconomical mining activities

4
1.1 Introduction

• There are many reasons of early closure of mines.
  Laurence (2002) indicates that in Australia
  over the past 25 years almost 70 per cent of the
  mines have had unexpected and unplanned closures.
  i.e. Mines are closed other than depletion of ore
  reserevs
• Laurence, DC 2002, Optimising mine closure
  outcomes for the communityLessons learnt,
  Minerals and Energy, Raw Materials Group, 17
  27-34.
• The main reasons are
• Economical Low commodity prices or high costs
• Geological An unpredicted decrease in grade or
  size of the ore body
• Technical Adverse geotechnical conditions or
  mechanical/equipment failure
• Regulatory Safety or environmental problems
• Policy changes Occurs from time-to-time,
  especially after government changes
• Social or community pressures Particularly from
  non-government organisations
• Closure of downstream industry or markets
• Flooding of the mine

5
1.1 Introduction

• ? Any mining project to have contribution to the
  development of the country and the society,
  should have closure plan according to developed
  closure policy.
• Mine closure policy and planning forms the basis
  of the end result of an mining project. ? It
  should be an integral part of a mine projects
  life cycle.

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1.1 Introduction

• Why is it of interest?
• Experience with abandoned mines shows that having
  improperly closed mines cause
• Safety and health hazards
• Degradation of land use
• Downstream environmental impact
• Difficult remediation conditions
• Public intolerance

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1.1 Introduction

• Why is it of interest?
• Poorly closed and abandoned mines cause bad
  legacy for governments, communities and minerals
  companies and, hence finally, tarnish the mining
  industry as a whole.
• As the resources becomes limited, effective
  closure processes and satisfactory mine
  completion becomes critical to a companys
  ability to develop new projects.
• Poor planning and inadequate financing commonly
  increase the costs of closure and decrease
  overall profitability, which jeopardize a
  companys ability to develop new projects.

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1.1 Introduction

• Mine Closure is necessary in order to
• Ensure public health and safety
• Protect physical and chemical deterioration of
  environmental resources
• Provide beneficial and sustainable after-use of
  the mine site in the long term
• Minimize adverse socio-economic impacts
• Maximize socio-economic benefits

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1.1 Introduction

• In order to achieve these objective at the end of
  mines life, a mine closure plan early in the
  process of mine development is compulsory.
• This plan should be prepared by consulting to
• Regulatory authorities
• Local communities

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1.1 Introduction

• A mine closure plan should satisfy and include
  the followings
• Achievement of sustainable development
• Design for closure
• Operations in accordance with closure plan
• Commitment of progressive site rehabilitation
• Framework of short term actions to be performed
  during mining activities
• Economic and social aspects for the future of the
  community
• Financial planning and assurance

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1.1 Introduction

• What happens if already opeating mine does not
• have a closure plan?
• The mines which are close to the end of their
  economic life have very limited alternatives to
  satisfy all the goal of closure plan
• The mines which are in the middle of their
  economic life have more opportunities
• The mines which are still in planning and design
  stage phase have maximum flexibility to take
  actions for satisfying all the goals of closure
  plan.

Planning Phase
Mid-Life
End of economic life
Maximum options
More options
Limited options
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1.1. Introduction

• The activities during the final closure stage
  include
• The removal of infrastructure
• The implementation of public safety measures,
• Recontouring and revegetation (rehabilitation)
• Ongoing maintenance of site structures and
  monitoring of environmental issues,
• The operation of site facilities required to
  mitigate or prevent long term environmental
  degradation
• The completion of company involvement in
  sustainable community economic and social
  programmes.

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1.2. Time Span of Mine Closure

• The time span of mine closure varies for every
  mine. However, there are some general principles
  which apply to all mines
• Closure plans should be developed as early as
  (i.e. during the feasibility and design stages
  of new mines) possible.
• The closure objectives and design should be
  reviewed continuously to adapt for changes in
  political, legislative, physical or
  socio-economic conditions.
• The delayed closure plans can limit the
  achievement of closure objectives.

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1.2. Time Span of Mine Closure

• It can be said that mine closure planning is a
  continuous process that should start during the
  pre-feasibility stage of a mine project
• At this stage it has to be considered as an
  integral part of the environmental and social
  impact assessment.

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1.2. Time Span of Mine Closure

• Rehabilitation or reclamation plans which are a
  part of mine closure should be implemented
  through out the operation of mine which includes
  the use of site (dump sites, tailing dams etc.)
• The reclamation plans are prepared as part of the
  environmental impact assessment and should be
  reviewed during mine life and integrated into
  mine closure plans

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1.3. Factors to be Considered

• Planning for closure includes
• Integration of the closure design for the entire
  mine area.
• Identification of planning process time
• Consideration of waste disposal methods, economic
  and community objectives with financial
  perparations

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1.3. Factors to be Considered

• Requirements of a closure plan
• A study of closure options evaluating the
  feasibility of all aspects of possible outcomes
• A consultative process involving all interested
  parties, to determine the preferred after use for
  the mine and associated facilities
• A statement of closure objectives the mining
  companys commitment to the outcome of the
  closure of its activities
• An estimate of closure costs the cost of
  achieving the stated objectives
• A programme of studies and test work to confirm
  any assumptions inherent in the closure
  objectives.

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1.3. Factors to be Considered
Example The closure planning process given in
the Mine Closure Guideline for Mineral Operations
in Western Australia (Chamber of Minerals and
Energy, 1999).
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1.3. Factors to be Considered

• The following aspects of closure should be taken
  into account for sustainable development
• Environmental
• Socio-economical
• Business

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• The post-mined landscape should be safe and
  stable from physical, geochemical (chemical) and
  ecological (landuse) perspectives
• The quality of the surrounding water resources
  should be protected
• The agreed sustainable post-mining land use
  should be established and clearly defined to
  satisfy the community and government
• The success criteria should be agreed with
  relevant stakeholders, monitored and reported to
  the stakeholders

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• The development of a mining operation, including
  associated processing facilities and
  infrastructure, usually involves
• permanent alteration of existing landforms
• disturbance to vegetation and flora
• disruption of fauna habitats
• hydrological impacts
• potentially some level of contamination.

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• Alterations of Landforms due to mining
  activities
• Topography and landform
• Temporary changes
• access and haul roads
• laydown and hardstand area
• topsoil stockpiles
• process plant site, and support infrastructure.
• Permanent changes
• open pit void
• waste rock dumps
• tailings storage facilities.
• subsidence

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• Flora and vegetation Direct impacts on flora and
  vegetation occur during clearing for
• the mine
• waste rock dumps
• processing plant
• tailings storage facility and associated
  infrastructure.

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• Fauna
• The primary impacts
• Direct destruction of habitats through land
  clearing and earthmoving activities
• The secondary impacts
• Relates to activities with varying degrees of
  disturbance beyond the immediate point where
  mining is taking place, such as access and haul
  roads, powerlines, pipeline corridors and other
  infrastructure.

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• Surface water hydrology and groundwater The
  development of
• open pits
• Stockpiles
• waste rock dumps
• tailings storage facilities
• processing plant and infrastructure
• often interrupt some of the natural drainage
  paths.
• Interference with drainage patterns may result
  in
• deprivation of water to drainage systems
  downstream of the mining developments

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• Soil and water contamination
• Chemical reactions in waste rock and tailings
  have the potential to be detrimental to plant
  growth and to result in contamination of both
  surface and groundwater.
• Mining and processing operations transport, store
  and use a range of hazardous materials including
  fuels, process reagents, lubricants, detergents,
  explosives, solvents and paints.
• If these materials are not properly managed, they
  may have the potential to cause atmospheric, soil
  or water contamination and could potentially pose
  ongoing risks to human health and the environment.

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• Environmental management of these issues during
  operations can assist in minimising the impacts.
• However, there will inevitably be residual
  impacts at the completion of the mining and
  processing operations that will need to be
  managed with regard to the following priorities
• Public safety hazards and risk
• Potential sources of ongoing pollution
• Future land use and resource demands
• Ecological compatibility
• Community expectations
• Aesthetics
• Cost

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1.3. Factors to be Considered

• Environmental issues for sustainable development
• Many of the environmetal issues and impacts
  depend on the nature of the project and
  site-specific environmental factors.
• It is therefore important to define these aspects
  and impacts for each project as part of the mine
  closure planning process.

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1.3. Factors to be Considered
Environmental issues for sustainable development
Source http//www.deq.state.mt.us/abandonedmines/
mine_hazards.asp
Tailings with Metal Contamination
Mill and Eroding Waste Rock
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1.3. Factors to be Considered
Environmental issues for sustainable development
Tailings filling High Ore Creek valley at Comet
Mine in 1997 before removal(Photo courtesy of
David Nimick, USGS Source http//amli.usgs.gov/p
ictures/bimage6.html)
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1.3. Factors to be Considered
Environmental issues for sustainable development
Unstable slopes
Source http//www.deq.state.mt.us/abandonedmines/
mine_hazards.asp
32
1.3. Factors to be Considered
Environmental issues for sustainable development
Source http//www.deq.state.mt.us/abandonedmines/
mine_hazards.asp
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1.3. Factors to be Considered

• Socio-Economic issues for sustainable development
• Any mining activity have contribution to
  socio-economic status of the communities and
  regional development. Hence during mine closure
  the adverse impacts of mining on neighbouring
  communities should be considered.
• How to maintain or improve the wellbeing and
  social sustainability of affected communities
  should be identified.
• What is social sustainability?
• It refers to the formal and informal processes,
  systems, structures and relationships within a
  community that actively support the capacity of
  current and future generations to create healthy
  and liveable communities.
• Socially sustainable communities are equitable,
  diverse, connected and democratic, and provide a
  good quality of life.

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1.3. Factors to be Considered

• Socio-Economic issues for sustainable development
• Community Development Programs
• They are concenred with increasing the strength
  and effectiveness of communities in determining
  and managing their own futures. They also
  provide an important mechanism through which a
  mining company can contribute to social
  sustainability.
• It involves planning and implementing
  initiatives, often in partnership with other
  stakeholders, to provide long-term positive
  outcomes for affected communities.
• Community development should be driven by the
  needs of the community, not the company and
  should seek to contribute to the long-term
  strengthening of community viability.

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1.3. Factors to be Considered

• Socio-Economic issues for sustainable development
• Contribution of Mining Activity to the Community
• In many remote and regional areas, mining
  operations provide the only significant
  mainstream economic activity and have a critical
  role and contribution to make to regional
  economic development.
• Mining operations provide clear training and
  employment opportunities across the professions,
  skills and services.
• In some cases,mining companies are extending
  their commitment to local economic development
  and capacity building by requiring that
  contractors also target their training and
  employment opportunities to the local community,
  and by giving preference to a local supply chain.
  
• Mining companies are also seeking to provide
  appropriate skills-transfer and employment
  opportunities through the development of local
  business enterprises.

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1.3. Factors to be Considered

• Socio-Economic issues for sustainable development
• Contribution of Mining Activity to the Community
• The establishment of a mining or minerals
  operation almost always brings significant
  infrastructure to the mine site, to the local
  community and to the broader region.
• Planning for mine closure can assist in
  mitigating the consequent reduction in access to
  useful infrastructure.
• With advanced and careful planning, it may be
  possible to develop capacity to maintain certain
  infrastructure facilities and services for future
  community or local government

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1.3. Factors to be Considered

• Socio-Economic issues for sustainable development
• Planning for mine closure should be raised with
  the community as early as possible prior to the
  planning and design phase.
• The project design should consider how to
  minimise the adverse impacts of mine closure and
  to optimise the opportunities for community
  development that arise from the active mining and
  mine closure phases.
• An early and effective community engagement
  strategy should be established and the community
  engaged throughout the life of the operation.

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1.3. Factors to be Considered

• Business issues for sustainable development
• If mine closure is planned in a sustainable
  development framework and implemented over the
  whole mine life in a systematic manner, it will
  have many benefits in tems of business
  perspective
• Improvement in mine management
• Improvement in stakeholder engagement during
  planning and decision making
• Risk and liability reduction

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1.3. Factors to be Considered

• Business issues for sustainable development
• Improvement in mine management
• Optimization of opportunities for mine planning
  and operations during active mine life so that
  resources are extracted efficiently and
  post-mining land use is planned effectively
• E.g. reduction of double-handling for waste
  materials and topsoil, and reduced areas of land
  disturbance
• Identification of high risk areas to prioritize
  for ongoing research or remediation
• Progressive implementation of a mine closure plan
  with opportunities for ongoing effectiveness
  testing, assessment and feedback lower risk of
  regulatory non-compliance

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1.3. Factors to be Considered

• Business issues for sustainable development
• Improvement in stakeholder engagement in planning
  and decision making
• It makes easier for explaing the likely impacts
  on affected communities in terms of
  environmental, social and economic impacts of
  mine closure.
• It forms informed development of strategies and
  programs to address closure impacts, ideally as
  part of a community development approach from
  early in the mines life
• It increases support from employees, government,
  landholders, local community and other
  stakeholders for closure decisions
• It enhances community receptiveness to future
  mining proposals
• It increases public image and reputation

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1.3. Factors to be Considered

• Business issues for sustainable development
• Risk and liability reduction
• Assurance of financial and material provision for
  mine closure through early estimation of mine
  closure costs
• Continual reduction of liabilities by optimising
  operational works during active mine life in
  alignment with closure plan
• Reduction of exposure to contingent liabilities
  related to public safety and environmental
  hazards and risks
• Reduction of ongoing responsibilities for the
  site.

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1.4. Mine Closure Planning
Phases of a mine project
The effectiveness and success of closure planning
depends on consideration of closure at every
phase of the project.
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1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Exploration

• At this phase there is no guarantee for the
  project to become alive. However, even at this
  phase environmental and social impacts should be
  considered. They include
• access tracks
• drill pads
• disposal of wastes,
• community concerns and expectations.
• In addition the companys community engagement
  begins at this phase, which may require
  negotiations and the consent of land owners or
  Iocal community. The nature of community
  engagement at this stage is important due to its
  effect on future relations.

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1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Exploration

• Key activities to be considered a this phase
  which will be useful for future planning and
  closure are
• Development of a community engagement plan based
  on
• community and stakeholder identification and
  analysis
• socio-economic baseline study and social impact
  assessment
• engagement with the local community residents
  may advise how places or objects of cultural
  significance should be protected
• Preliminary discussions with community and
  stakeholders on the mine concept and collation of
  issues that need to be addressed in future
  environmental impact assessments (EIAs) or source
  impact assessments (SIAs)
• Collection of early environmental baseline data
  including surface and ground water quality and
  quantity, soil types, vegetation types,
  meteorological data
• Preliminary assessment for waste rock
  characterization including testing of sulphide
  ore bodies for acid-based accounting and metals
• Development of relationships with local
  stakeholders, regulators and community
• Preliminary assessment of current land use and
  ownership.

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1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Feasibility

• In many countries, a preliminary closure plan is
  required by the regulatory authorities as part of
  the approval process of the mine project at
  feasibility stage. This plan is necessary for
• assessment of the project
• the environmental controls required
• the long-term potential liability posed by the
  project

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1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Feasibility

• Typical issues to be considered for mine closure
  that should be included in the feasibility
  assessment include
• Potential area of disturbance
• Environmental sensitivity of flora and fauna,
  surface and groundwater quality
• Volumes and types of wastes to be stored,
  including waste rock and tailings
• Characterization of wastes including
  geotechnical properties
• Appropriate locations and required capacity of
  water storage facilities for consumption,
  process supply, and site water management.
• Geotechnical stability of ground surface and
  engineered structures
• Regulatory requirements for design and closure
• Proposed designs for waste storage facilities
  and costs to rehabilitate and close
• Social and economic development and
  sustainability issues, such as local enterprise,
  post-closure use of land and infrastructure, and
  other community development programs.

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1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Planing
Design

• The goal of mine planning and design
• To achieve an integrated mine systems design in
  which ore is extracted and prepared for the
  market at a minimum unit cost within acceptable
  environmental, social, legal and regulatory
  constraints.
• Hence It is a multidisciplinary activity.
• Mining engineers and mine geologists generally
  have the most influence in mine planning and
  design. They need to understand and take into
  account the mine closure issues, and integrate
• Economic
• Environmental
• Social elements
• into the decision-making process.

48
1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Planing
Design

• For example, mining engineers need to be informed
  about the preliminary community expectations for
  
• post mining land uses
• the environmental quality
• the aesthetics of the area.
• These expectations can impact, for example, on
  the location of access roads and waste storage
  facilities.
• Hence Engineers and geologists should colleborate
  with
• Environmental
• Social scientists
• in their decision-making

49
1.4. Mine Closure Planning Closure Considerations
in Mine Project Phases Planing Design

• Decisions made during the mine planning process
  will have significant and long-term consequences
  for the mine and its environment.
• Mine planners should balance short-term cost
  savings against potential long-term issues.
• For example, a mining engineer may make the
  decision to mine a deposit by open-pit methods
  rather than by underground. This may allow
  quicker access to ore and therefore earlier cash
  flow, but it will result in higher volumes of
  waste and, if the waste is mineralized, it may
  result in later acid rock drainage issues.

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1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases
Construction

• Construction activities at a mining project
  create visible changes and impacts on the
  environment and community.
• This short-term stage requires the highest level
  of employment, which exceeds the longer-term
  workforce requirements.
• The influx of a construction workforce can
  provide economic benefits to the local
  community, and particularly local businesses, but
  it can also put pressure on local services and
  have a negative social impact on the community.

51
1.4. Mine Closure Planning Closure Considerations
in Mine Project Phases Construction

• Typical construction activities include
• access roads and airstrips
• construction and accommodation camps
• power supply (electricity, gas or diesel)
• fuel and chemical storage facilities
• water supply
• process plant
• workshops and warehousing
• contractors lay down areas
• offices, change rooms
• crushing plant
• tailings storage facilities
• waste rock, low-grade and other dumps, and
  stockpile preparation.

52
1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases
Construction

• At this stage construction contractors and
  personnel should realize that their activities
  may have impact on the eventual closure of the
  mine.
• Mines can close during the commissioning and
  construction stage due, for example, to budget
  overruns.
• Therefore activities disturbing the site should
  be kept to a minimum during this phase.
• It is also important that local landowners and
  the local community are not unnecessarily
  inconvenienced at this time and that the
  foundations for long-term relationships are
  built.
• During this phase, planning and design decisions
  can have long-term consequences for the
  environment, future land uses, community health
  and safety that will impact upon the mine closure
  and completion process.

53
1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases
Construction

• Examples of long-term consequences would be
• Poor foundation construction for a tailings dam
  or water storage ponds can lead to long-term
  seepage and potential groundwater contamination
• Waste rock dumps designed to handle sulfidic
  waste need to have appropriate low permeability
  foundations and/or acid consuming material placed
  as a basal layer
• Poor erosion controls during construction can
  result in increased sediment loads to water
  courses during rainfall events
• Proper storage and handling of fuels and
  lubricants, and sound workshop management can
  reduce long-term contamination from spillages
• Proper identification and handling of topsoils
  and other growth media, and control of dusting
  from these stockpiles, can assist immediate and
  long-term environmental management.

54
1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Operations

• The operational phase of a mine can extend for
  many years typically from five to 20 and, in
  some cases, more than 50 years (for example, coal
  and bauxite mines).
• During this period there will be operation
  changes, plant expansions and progressive
  rehabilitation.
• There could also be changes in ownership with
  potentially different management approaches.

55
1.4. Mine Closure Planning- Closure
Considerations in Mine Project Phases Operations

• The operations phase can be divided into three
  stages
• Commissioning stage The period after
  construction which can typically include initial
  commissioning, start up and pre-stripping for
  pits, construction of waste rock dumps and
  tailings storage facilities.
• Mature stage The mid-mine phase where most of
  the disturbance has taken place and the mine is
  in steady operations
• Pre-closure planning stage This may be five
  years or more before known ore resources are
  exhausted.

56
1.4. Mine Closure Planning -Closure
Considerations in Mine Project Phases Closure

• Closure involves
• The implementation of the closure plans developed
  in the earlier stages
• The conduct of the necessary investigations
• Studies to identify potential contamination
• Confirmation of the agreed outcomes and criteria
  met.

57
1.5. Activities of Mine Closure

• Typical closure acivites are
• Demolition and removal of infrastructure
• Reshaping of remaining mining landforms
• Completing the rehabilitation and remediation
  processes
• Monitoring and measuring the performance of
  closure activities against the agreed standards
  and criteria
• Inspections, consultation and reporting to the
  stakeholders
• Progressive community and government sign off.

58
1.5. Activities of Mine Closure
Mining projects are usually divided into nine
main components Underground Mining Open Pit
Mining Rock and Overburden Piles Tailing
Impoundment Water Management and Water Treatment
Chemicals Buildings and Equipment Land Fills
and Other Wastes Infrastructure Each component
has to be considered based on Physical stability
Chemical stability Land use
59
1.5. Activities of Mine Closure
A typical mine layout
60
1.5. Activities of Mine Closure
Closure for Underground Mining (Sassoon,
1996) Sassoon, M (1996) Closure or Abandonment.
Mining Magazine, August,
61
1.5. Activities of Mine Closure
Closure for Underground Mining Underground
workings of Cascade Mine, source
http//www.abandonedmines.net/cascade.htm
62
1.5. Activities of Mine Closure
Closure for Underground Mining Tunnel entrance of
Peter Mine, source http//www.abandonedmines.net/
peters.htm
63
1.5. Activities of Mine Closure
Closure for Underground Mining Shaft of Standish
Mine, source http//www.abandonedmines.net/standi
sh.htm
64
1.5. Activities of Mine Closure
Signs for Abandoned Mines, source
http//minerals.state.nv.us/programs/prog_aml.htm
65
1.5. Activities of Mine Closure
Signs for Abandoned Mines, source
http//minerals.state.nv.us/programs/prog_aml.htm
Source http//www.msha.gov/KIDS/ABANDON/UNDER.HTM
66
1.5. Activities of Mine Closure
Closure for Open Pit Mining (Sassoon,
1996) Sassoon, M (1996) Closure or Abandonment.
Mining Magazine, August,
67
1.5. Activities of Mine Closure
Closure for Open Pit Mining
An abandoned open pit mine at Hixbar mining area,
Sourcehttp//www.adnu.edu.ph/institutes/inecar/ra
pu-rapu/reason03.asp
68
1.5. Activities of Mine Closure
Closure for Open Pit Mining
Contaminated creek in the downstream of mine,
Sourcehttp//www.adnu.edu.ph/institutes/inecar/ra
pu-rapu/reason03.asp
69
1.5. Activities of Mine Closure
Closure for Open Pit Mining
Contaminated creek in the downstream of mine,
Sourcehttp//www.adnu.edu.ph/institutes/inecar/ra
pu-rapu/reason03.asp
70
1.5. Activities of Mine Closure
Closure for Open Pit Mining
Contaminated creek in the downstream of mine,
Sourcehttp//www.adnu.edu.ph/institutes/inecar/ra
pu-rapu/reason03.asp
71
1.5. Activities of Mine Closure
Closure for Open Pit Mining
A steep slope on the way to the open pit ,
Sourcehttp//www.adnu.edu.ph/institutes/inecar/ra
pu-rapu/reason03.asp
72
1.5. Activities of Mine Closure
Closure for Rock and Overburden Piles (Sassoon,
1996) Sassoon, M (1996) Closure or Abandonment.
Mining Magazine, August,
73
1.5. Activities of Mine Closure
Closure for Tailing and impoundments (Sassoon,
1996) Sassoon, M (1996) Closure or Abandonment.
Mining Magazine, August,
74
1.5. Activities of Mine Closure
Closure for Socio-Economic development (Sassoon,
1996) Sassoon, M (1996) Closure or Abandonment.
Mining Magazine, August,
75
1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• The following considerations should be made
• Baseline study
• Characterization and site selection of materials
• Education and training
• Health and safety
• Financial assurance

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1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• 1. Baseline Study
• What is it ?
• Collection of relevant social and environmental
  data to be used in decision-making process during
  the operational life and closure.
• What does it used?
• To set the license conditions for water, flora
  and fauna
• To identify closure criteria to be met at the
  end of a mining operation.
• Environmental Data The collection of it starts
  in feasibility phase and used for approval
  process. It database should be continuously
  enlarged by continuous data collection and should
  include spatial and temporal nature of the data.
• Social Data They give information about the
  development of the suitable community and other
  stakeholder engagement strategy.

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1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• 2. Characterization and site selection of
  materials
• For effective reclamation
• The detailed characterization of the soil
  properties, overburden and mineral processing
  wastes is essential in determining plant growth
  capacity and potential of adverse impacts on
  water quality.
• The site selection of these materials is
  essential to ensure creation of a suitable medium
  for plant growth for post-mined landscape and the
  protection of water resources.

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1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• 2. Characterization and site selection of
  materials
• Establishment sustainable ecosystems after mining
  requires the Conservation and replacement of soil
  resources over the mined area.
• Segregation and selective placement of overburden
  layers is conducted by burrying material if they
  can have adverse effect to plant growth or may
  contaminate surface or groundwater supplies.
• In the classification of various waste rock types
  and in overseeing their removal and placement
  during waste rock dump construction, experienced
  personnel should be incorpotared. Failure to
  maintain quality control in this phase of the
  mine operation can jeopardise environmental
  protection during operations and following
  closure.

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1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• 3. Education and Training
• An education/ training program is necessary for
  explaintion of
• the long-term mine closure goals
• the reasons why materials are segregated
• the potential long-term impacts on the
  environment and closure.
• It is important to educate mine contractors and
  personnel about what is required in relation to
  design, placement of soils and waste rock.
• It is difficult to encourage contractors and
  personnel to follow the design if they are not
  told the requirements and do not understand the
  logic and reasoning behind the process.

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1.5. Activities of Mine Closure Details of
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• 3. Education and Training
• Educating the workforce will make them to take
  responsibility for material segregation,
  placement, handling and data recording, which
  will make easy tracing of records and management
  of problematic wastes for managers.
• The education program should be systematic and
  requires regular reviews and rollout, especially
  for new contractors and employees.

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1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• 4. Health and safety
• Mining and minerals processing operations may
  have significant adverse impacts on the health
  and safety of employees and local communities if
  the hazards are not quantified and then
  proactively managed through the mine life cycle.
• The environmental release of hazardous substances
  can cause toxic and long-term chronic health
  effects for employees and for communities close
  to, downwind or downstream from operations.
• It can also compromise environmental values that
  are critical to the long- term sustainability of
  local communities, such as food and water
  supplies.

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1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• 4. Health and safety
• The main aim of the successfull mine closure is
  to ensure health and safety of the the community
  during and after mining.
• The mine closure phase can also introduce
  increased safety risks to employees, whofaced
  with mine closure and consequent loss of
  employment may have reduced motivation and
  morale, which can lead to workplace safety
  issues.

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1.5. Activities of Mine Closure Details of
Operation Stage-Early Mining

• 4. Financial Assurance
• The standards of rehabilitation required clearly
  affect the cost of the work and the amount of
  financial assurance required.
• Although mining is considered a temporary use of
  land, a requirement to return the land to its
  predisturbance condition, or to a condition
  permitting resumption of its earlier use, is not
  always achievable.
• Policy makers and industry need to develop
  practical criteria for assessing the adequacy of
  rehabilitation efforts.

84
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• The followings has to be taken into account
• Mine planning design developing the mine
  closure plan
• Domain requirements
• Establishment of a closure committee
• Evaluation of closure options
• Progressive rehabilitation
• Monitoring standards and performance
• Review of closure strategies and plans

85
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 1. Mine planning design developing the mine
  closure plan
• The mine closure plan is a living document that
  will be continually reviewed and revised over the
  mines life.
• The level of detail will vary as the mine matures
  and knowledge is gained on the significant
  issues to be addressed in the mine plan and
  options for dealing with them through closure.
• A typical approach to developing a mine closure
  plan is to segregate the mine into specific areas
  or domains.
• Each domain should be treated as a separate
  entity for detailed work plans, but within an
  overall plan which addresses the integration of
  the domains.

86
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 1. Mine planning design developing the mine
  closure plan
• For a typical mine, the site may be segregated
  into the following domains
• ore processing plant site
• shaft hoisting and headframe (for underground
  mines)
• workshops and hydrocarbon storage areas
• waste rock dumps (mineralised and barren)
• tailings storage facility
• process water and raw water dams
• pits or voids (underground declines)
• access roads, exploration tracks and service area
  infrastructure
• camps and accommodation areas.

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1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining
A typical mine layout
88
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 2. Domain requirements
• For each domain, a detailed closure plan will
  need to be developed. However, the plans for each
  domain should be integrated into an overall plan
  to address common issues such as the drainage
  pattern.

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1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 2. Domain requirements
• The followings should be considered for
  identifying the domain requirements
• area of disturbance
• review of legislation and regulatory requirements
  or license commitments
• identification of environmental hazards and risk
  assessment
• development of options for each major issue or
  hazard identified within the domain
• plan for deconstruction and removal of
  infrastructure
• understanding of likelihood for short-term and
  long-term contamination and
• management of identified contaminated wastes

90
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 2. Domain requirements
• The followings should be considered for
  identifying the domain requirements
• agreed final landform, landscape design and final
  land use
• earthworks plan required to create final landform
• erosion controls and drainage plan
• capping or other control mechanisms to manage
  potential contamination
• rehabilitation plan, plant species required, seed
  versus tube-stock, fertiliser
• requirements
• rehabilitation monitoring requirements to meet
  long-term sustainability targets or objectives
• water (surface, groundwater) monitoring program
  to meet site or off-lease license conditions
• cost estimates for deconstruction, earthworks and
  habitat reconstruction,
• revegetation, care, maintenance and monitoring.

91
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 2. Domain requirements
• The list is very comprehensive and can be unique
  for each domain. However, there are a number of
  repetitive tasks that are best incorporated into
  an overall site plan, which is the overall
  monitoring program across all domains (e.g.
  water, vegetation performance, erosion rates and
  other licensed activities)
• Computer programs linked to GIS and other mapping
  tools to accurately represent the land under
  management can be used for this purpose.
• By overlaying digital terrain models and using 3D
  software, actual as-built features can be shown.

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1.5. Activities of Mine Closure Details of
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2. Domain requirements Constructed landform
designs can also be easily created and displayed.
This can aid the mine planners and environmental
staff to design cost-effective landforms that
meet the closure goals. These programs also
provide visualisation of progressive
rehabilitation and final landforms for community
stakeholders, enable accurate volumes of material
to be calculated and allow the overall costs for
the work to be estimated.
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1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 3. Establishment of Closure Committee
• The establishment of closure committee serves
  for
• Consulting related to closure issue
• Developing an overall stakeholder engagement
  strategy
• Discussion of long-term objectives with various
  stakeholders and community representatives.
• The commitee also helps involvement of
  stakeholders and demonstration of community
  support to regulators.

94
1.5. Activities of Mine Closure Details of
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4. Evaluation of Closure Options Usually there
is no clearly defined methodology for mine
closure for achieving closure goals. e.g.1.
Development of a capping design for a waste rock
dump to minimise oxidation and generation of acid
rock drainage is uique for each mine. e.g. 2.
Field trials are required for the revegetation of
problematic soils or spoils. Many of the
overburden soils mined in the coal fields contain
sodic material, which is highly erodible, but
also has poor nutrient and growing
characteristics. Field trials and combinations of
additives, such as fertiliser, organic material,
lime and fly ash may need to be needed to
establish a growing medium that will encourage
revegetation to a standard appropriate to the
post-mining land use.
95
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining
4. Evaluation of Closure Options Research and
trials can take several years to establish,
monitor and modify before acceptable outcomes are
achieved. It is critical that these trials are
established long before the mine closes so that
the knowledge from the trials can be incorporated
into the final mine closure plans.
96
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining
5. Progressive rehabilitation Rehabilitating
progressively the sections of the mine reduces
the long-term closure liability and is encouraged
by most regulatory authorities. Actively
rehabilitating areas during the operational stage
can usually be cost-effective. Earthworks can be
completed when equipment is available or when
contractor equipment is mobilised to a site for
other jobs. The contract can often be extended to
undertake the rehabilitation works, saving on
mobilisation.
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1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 5. Progressive rehabilitation
• The main benefits of progressive rehabilitation
  are
• Reduction of the overall un-rehabilitated
  footprint of the mine
• Trial of various options and demonstration of
  rehabilitation outcomes to wider community
• Showing commitment to stakeholders and employees
  that the mine has an active mine rehabilitation
  program
• Reduction of the overall closure costs
• Reduction of the risk of failure and ultimate
  liability
• Reduction of the rehabilitation bond posted
  with regulatory authorities.

98
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 6. Monitoring standards and performance
• Monitoring the performance of closure activities
  is important for demonstratig the success of the
  objectives to stakeholders and regulatory
  authorities
• Typical monitoring programs that support a mine
  closure program can include
• Baseline monitoring in the early mine life phase
• Values to be protected or re-established
• Identification and establishment of unmined
  reference areas during pre- mining mapping and
  surveys.
• Monitoring, recording and understanding of all
  potential impacts during the operational phase of
  mining.

99
1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 6. Monitoring standards and performance
• Monitoring the performance of closure activities
  is important for demonstratig the success of the
  objectives to stakeholders and regulatory
  authorities
• Typical monitoring programs that support a mine
  closure program can include
• Documentation of the rehabilitation operations
• To confirm that agreed procedures have been
  implemented
• To assist when interpreting the findings of
  later rehabilitation monitoring results.

100
1.5. Activities of Mine Closure Details of
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6. Monitoring standards and performance Long-term
monitoring (two to three years after
rehabilitation) To evaluate the progress of
rehabilitation towards fulfilling long-term land
use objectives, To determine whether the
rehabilitated ecosystem is likely to be
sustainable over the long term. Post-lease
relinquishment monitoring To confirm the
sustainability of the post-mining land use under
the applied management regime. The responsible
parties and the extent of this monitoring depend
on a companys commitments and obligations, and
the information needs of stakeholders.
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1.5. Activities of Mine Closure Details of
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• 6. Monitoring standards and performance
• Assessment of data
• To identify problems and develop solutions during
  progressive rehabilitation
• Research and field trials should be undertaken to
  determine which techniques work and which do not.
  Usually, research on rehabilitation operations
  require technical experts from universities and
  other research institutions to address specific
  areas of
• soil development
• nutrient cycling
• fauna monitoring,
• timber and agricultural productivity

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1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining
6. Monitoring standards and performance Stakehold
er Engagement Measuring and monitoring
community engagement and development prior to,
during, and post-closure, provides gaining
feedback from all stakeholders regarding options
and alternatives building relationships of
trust or repair fractured relationships
maintaining the social licence to operate
helping mitigating dependency benchmarking
closure/community plan effectiveness enhancing
the potential for sustainable mine closure
(completion).
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1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining

• 7. Review of closure strategies
• Throughout the mines life, closure strategies
  should be regularly reviewed
• To ensure they are appropriate
• To address the major issues for closure
• To remain aligned to community expectations and
  regulator requirements.
• The collection of appropriate and accurate data
  through monitoring programs is critical to this
  process and will assist managers in
  decision-making.
• The review process provides an ideal opportunity
  for engagement with stakeholders through
  community committees and the building of
  relationships that develop trust and confidence
  in the operation.

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1.5. Activities of Mine Closure Details of
Operation Stage- Routine Mining
7. Review of closure strategies Anual
Review An annual review of the closure plan
should be a standard practice for the companies
and also the regulators as they require Annual
statistics on areas of disturbance Areas
rehabilitated in previous year Areas yet to be
rehabilitated In addition, the company and
relevant stakeholders usually require a review of
the closure cost calculations (liability) as part
of annual accounting policy and procedures. The
closure plan is a key reference document during
this process, as it demonstrates to accountants
and auditors the philosophy and strategies to be
undertaken.
105
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure

• The followings has to be taken into account
• Finalization of closure plan
• Minimization potential environmental liability
• Valueing the assets and planing for the asset
  sale/transfer process
• Development of a deconstruction plan
• Development of a human resources plan
• Implementation of the plans

106
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure

• 1. Finalization of closure plan
• It should cover
• Plans for the maintenance
• Demolition or removal of infrastructure
• Rehabilitation
• Safety and social obligations release of staff
• Retention of key people.

107
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure

• 1. Finalization of closure plan
• The key people that should be involved in this
  process are
• Environmental and community relations staff
• An experienced mine planner with project
  management skills
• People experienced in change management who are
  able to embrace change and work with a wide range
  of employees, contractors, regulators and other
  people involved in the closure process

108
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure

• 1. Finalization of closure plan
• At this stage mine is divided into a number of
  domains. A detailed plan needs to show the tasks
  to be undertaken step-by-step and also the
  resources required to do the job (equipment,
  people, supervision and contract resources).
• The plan will need to consider other essential
  services like
• Power
• Water
• Maintenance workshop availability
• Most of the time, portable generators and mobile
  workshops need to be hired as key infrastructure
  is removed and power is still required for
  maintenance and deconstruction equipment.

109
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure
2. Minimization of Potential Environmetal
Liability Closure provides an opportunity to
reduce the environmental liability by managing
the waste streams. This can also create come cost
savings. ?E.g1 Processing oxide material
through the plant and sending the oxide material
to tailings to create a benign layer, or cover,
over more reactive tailings. This may be a
cost-effective solution, rather than the
traditional truck and shovel placement of benign
solids over a tailings impoundment which may
require material sourced from outside existing
disturbance.
110
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure
2. Minimization of Potential Environmetal
Liability Closure provides an opportunity to
reduce the environmental liability by managing
the waste streams. This can also create come cost
savings. ?E.g2 When undertaking the inventory
of sites to be rehabilitated, each pile of rock
or tailings should be looked at as a possible
resource that could be used to rehabilitate
another area. By considering the potential risk
to the environment of each waste pile, creative
opportunities may arise where a waste material
may be used to minimise a risk factor on another
waste pile, such as a pile of coarse durable
waste rock used to rock armour another pile of
proven erodible soils. The durable rock may also
be seen as a valuable resource by the local
council for road construction works, providing it
is chemically benign.
111
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure
2. Minimization of Potential Environmetal
Liability Closure provides an opportunity to
reduce the environmental liability by managing
the waste streams. This can also create come cost
savings. ?E.g3 Placement of highly reactive
sulphide material in the base of a pit or back
underground where it will be submerged under
metres of water to stop oxidation reactions will
be a superior outcome compared with construction
of an engineered soil cover that may fail in the
future. The short-term, higher cost may be more
cost-effective in the long-term if, for example,
a water treatment plant is required to capture
and treat poor quality effluent for many years.
112
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure

• 3. Valueing the assets and planing for the asset
  sale/transfer process
• Before assets are sold, they need to be valued
  and a detailed itemised inventory should be
  completed. This is a significant task for most
  mines and should be started several years before
  closure.
• Spare parts and maintenance records for mobile
  and fixed plant need to be included, as they can
  value add to the sale.
• The sale process needs to be established by mine
  management.

113
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure

• 3. Valueing the assets and planing for the asset
  sale/transfer process
• There are three main types of sales approaches
  used
• prior sale agreement usually through a tender
  arrangement or equipment broker
• individual items sale through advertisements
• general public auction.
• It is usual to engage an experienced equipment
  sales broker and auctioneer, who will act on the
  companys behalf to sell all plant, buildings and
  equipment on a commission fee contract.
• Expected returns for a well-used plant and mobile
  equipment is 12 per cent to 20 per cent of new
  price.

114
1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure
3. Valueing the assets and planing for the asset
sale/transfer process There may also be the
opportunity at this stage to transfer some assets
to local communities or local businesses and not
to demolish infrastructure that may be of
assistance to the local community.
?E.g Demountable buildings, furniture and
equipment, fencing or a water bore may be highly
valued by the local community. Further, the
community or local council may also request that
access roads and airstrips are not demolished.
This will require negotiations and planning to
ensure that there is a clear transfer of assets
or infrastructure that does not impose any
further liabilities for the company.
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1.5. Activities of Mine Closure Details of
Operation Stage- Pre-Closure

• 4. Development of a deconstruction plan
• In order to prepare a deconstruction plan,
  suitable civil engineering deconstruction
  experts or cost estimators should b