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  • 5/21/2018 Mine Closure


    Mine Closure

    1 Introduction and Basic ConceptsIntroduction

    What This Course is About

    In theory, mine closure is simple; in practice, it is difficult. In this course, we will start with the

    simple and then move to the more difficult, which will be explained in terms that will enable

    you to deal with the many issues that arise as you plan and implement mine closure.

    The simple part of mine closure consists of three objectives:

    remove equipment and structures;

    stabilize waste piles; and control the spread of pollutants from the closed site.

    As we shall see, these three simple objectives quickly give rise to many questions and knotty


    Who pays?

    Who says enough is enough?

    What is to become of the site in the long term?

    Many more related and difficult issues arise. Reading only this course will not enable you to

    solve all the problems. Each mine site is unique and demands a unique closure plan andapproach. You will undoubtedly have to formulate the specifics of the closure plan for your

    mine by way of many studies, meetings, reports, and deep deliberations. This course will

    attempt to set down the current state of ideas, practice, and possibilities, so that you are

    empowered to move forward to success as part of a team charged with mine closure.

    Personal Perspectives

    I write this course from a personal perspective based on many years of

    involvement in designing, helping operate, and closing mines and mine

    facilities, particularly tailings impoundments. For five years I wasactively involved in the engineering of a major US project to close

    twenty-four uranium mill tailings impoundments. That experience

    gave me the opportunity to think deeply about the issues of mine

    closure. In addition to an active consulting job, I have spent the past

    five years reading and writing about all aspects of mines and mining.

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    Thus, I prepare this course as an introduction to a subject that is vast and sprawling, involving

    social, technical, and financial issues. In the final section of this course I list and comment on

    many e-documents readily available on the web, and likely to remain available over time. I

    recommend these for your perusal once you have made your way through this course. For the

    most part, I purposely avoid providing links in the body of the course. Links break, go out of

    date, and are superceeded by new information and comment. Thus if a topic, idea, or specificsite mentioned in the body of the course interests you, simply undertake a Google search and

    you will undoubtedly find more information related to it.

    Be advised that the science, art, or philosophy of mine closure is still in a state of flux. There are

    no generally accepted or implemented standards or procedures in any aspect of mine closure.

    There is considerable debate about all of them, and in particular about closure standards, post-

    closure site use, funding for closure, and the social responsibility of the mining company in the

    event of premature and even final closure of a mine.

    For Whom is this Course Written?

    Many people and many disciplines are needed to successfully plan and implement mine

    closure. Here are some, in alphabetical order. This course is intended to introduce all of the

    following to mine closure concepts and practice and to help them better close mines.

    Accountantsand financial folk are going to have to find the money to pay for closure. Good

    accountants will make adequate provision for closure costs starting at the beginning of mine

    life. Bad accountants will postpone the inevitable, and then very skilled accountants are

    needed to find money in a non-profit-generating company.

    Backwoodsmenand all the people who love and enjoy nature want to see the site returned

    its natural state so they may go hunting, fishing, riding, camping and dreaming in an area free

    of human intervention. These folk may be the locals, the community, the ancient owners of

    the site, or they may be fleeing the city for nature and a bit of peace.

    Civil engineers and other engineers have to design, construct, and ultimately maintain the

    civil works that are part of a well-executed mine closure. Ironically, closure of a worked-out

    mine is primarily a great civil engineering undertaking. The mining engineers have generally

    moved on to a new mine to extract more coal, gold, silver, and other metals and minerals on

    which society depends for its wellbeing. The civil engineer is left behind to clean up and

    make the landscape stable.

    Designerswill have to formulate the closure landscape, locate the mounds and berms, set

    the courses for new streams and wetlands, specify where the vegetation will go and hence

    formulate a natural-like landscape. This has been done at the Wapisaw Lookout site, the first

    closed oil sands tailings impoundment in Fort McMurray, Alberta.

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    Environmentalistsare the highly trained specialists who have to compile the environmental

    studies and write the closure environmental impact statements to justify the chosen closure

    approach. Included in this group of specialists are the risk assessors, the health and safety

    specialists, the vegetation folk who have to make grass and trees grow where they would not

    naturally do so, and so on.

    Fish and fowl specialistshave to decide how best to reclaim the site so that fish and fowl are

    not affected, and may even come to once again inhabit the site.

    Geologists and geomorphologists define the geology of the site and surrounding region so

    that we may apply the best principles of science to make a site stable in the long term.

    Geomorphologists are key to successful mine closure, for if we do not invoke and emulate

    natural geomorphic processes, we will soon be back to re-close the site.

    Hydrologistsand other hydro folk deal with water from the time it falls as rain to when it runs

    across the surface, infiltrates to groundwater, and becomes polluted at ill-closed mines.

    Inspectorsmust come to check on closure construction works and confirm that the site is

    performing as intended in the many years after closure.

    Journalistswill have to be kept informed, and are charged with writing about closure in a

    responsible manner so as to keep the public informed and hopefully supportive of closure


    Knowledgeable NGOs will have opinions, arguments, and rationalizations for ever-more-

    expensive solutions. It is best to know them, communicate with them, and reach a

    compromise wherever possible.

    Lawyers find and interpret the rules and regulations and tell us how they affect closure

    planning and construction now and in the long-term future.

    Miners involved include the mine planners, the mine managers, the mine community

    relations staff charged with dealing with affected local communities, and the mine engineers

    and technical staff who undertake the hard work of physically closing the mine and

    constructing the necessary closure works.

    Managersof all types and levels of authority manage the many teams that will plan, design,approve, and implement mine closure works.

    Native peoplesare those who feel a claim to the site; the length of time they have been in

    the area will vary. They may have a treaty from the Crown, a legal title, or they may be the

    possessors of the land around the mine. Whatever the case, you should deal with them, for

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    they will be there when you are long gone.

    Operations technicians will be required to do the hands-on work at the site - from

    groundwater well monitoring to control of water treatment plants.

    Permitting specialists will have their hands full identifying the many permits that have to be

    obtained to proceed. Theirs is a job of patience, skill, and necessity; for every mine being

    closed is sure to be where many permits are required to do everything from digging and

    planting to diverting streams and rivers.

    Quality control and quality assurance practitionersmust make sure we do what we say we

    will do and that we do it in accordance with pre-formulated plans and procedures.

    Regulatorshave the most difficult job of all: make sure the closure works are done properly,

    for if they fail, you can be sure the taxpayer will end up paying in the long term.

    Specialists in disciplines too many to list will be involved, from the anthropologist to the

    zoologist - you will be introduced to most of them as you proceed through this course.

    Treatment specialists include those who design, build, and operate the water treatment

    plants that are so often needed to clean-up polluted runoff and seepage from the closed

    mine site. This ensures that downstream waters are not contaminated but instead return to

    pristine conditions where wildlife may once again flourish.

    Underground minersplan closure of the underground mine workings so that they are not

    accessible in the long-term, so that they do not subside to disrupt the surface, and so that

    they do not become a source of polluted water.

    Visionarieslook into the future to tell us what may occur so that we may choose to provide

    for postulated future events or to leave those problems to future generations. In this

    category fall those advocates of global warming who are even now demanding more and

    more of mine closure works to deal with speculated global warming scenarios of serious


    Workers of all types and skills will come with the contractors to demolish old buildings,

    remove equipment, regrade slopes, and construct surface water management structures.

    X, Y, and Zstand in for all the rest who we will meet in this course, from labor union bosses to

    capitalists seeking to develop wind farms, from bloggers (like me) to zealots of all

    persuasions; and do not forget the politicians, without whom nothing would succeed in

    difficult circumstances.

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    From this list we can quickly see that mine closure is multi-disciplinary

    and demanding. The success of mine closure depends on how these

    diverse skills and talents are brought together to form a whole, and to

    cost-effectively do what has to be done. This course is intended to set

    out some of the things the team will have to consider, plan for, and act


    Why Mines Close

    Why do mines close?Laurence (2006),notes the following reasons.

    economic, due to either low commodity prices or high operating costs

    geologic, due, for example, to an unanticipated decrease in grade or

    size of the orebody

    technical, due to adverse geotechnical conditions or mechanical or

    equipment failure

    regulatory, due to safety or environmental breaches

    policy changes, which occur from time to time, particularly when governments change

    social or community pressures, particularly from NGOs

    closure of downstream industries or markets

    flooding or inrush of groundwater

    Closed mines may sometimes reopen when the metal price increases - consider recent

    increases in the price of gold and copper. More intelligent exploration may lead to the

    discovery of additional ore. The technical issues may be solved and the regulators placated.

    Social pressures may change as those who formerly earned a good mining income are faced

    with unemployment and hard times. And so on. It is worthwhile to consider the possibility ofre-opening the mine in future while planning its closure.

    Basic Technical Concepts and Issues


    Now that we have a basic idea of the people involved in mine closure and we understand why

    mines may close, we can set down the basic issues that arise in planning and undertaking mine

    closure. In the remainder of this course we will explore each of these issues in some detail, so

    consider the following an introduction to the remainder of this course and its contents.

    Closure Standards

    The laws and regulations that govern mine closure vary from place to place. Clearly you have to

    obey the law. But laws and regulations are seldom such that they mandate simple and obvious

    closure design criteria and standards. In a separate section of this course, we will explore the

    great diversity of mine closure criteria derived from laws, regulations, and current practice.

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    Tread carefully in establishing clear and unequivocal closure criteria - but you must do it,

    otherwise you are embarking on a never-ending trek of ever-increasing demands to do more

    and more. In establishing mine closure criteria and in planning their practical implementation,

    you need a concept of the post-closure use of your mine site.

    Post-Closure Land Use

    The mine on which I grew up closed after nearly fifty years of operation. Now the site is covered

    with buildings where artificial diamonds are manufactured. A mine for which I designed the

    tailings impoundment closed after twelve years of profitable operation. Now the old buildings

    house horse stables and the impoundment is part of the area where people go horseback riding

    in the clean air and rugged mountains. Some old mines become museums, some are turned

    into nurseries producing baby plants for new forests and farms, and some become schools or

    religious retreats.

    Too many closed mines are a burden, and are surrounded by high fences to keep trespassersout. It need not be thus, and in this course we will explore innovative ideas for post-closure use

    of the mine site.

    Phases of Mine Closure Planning

    In the past, mine closure planning was undertaken as the mine approached closure, or worse,

    once it closed sooner than intended. Mine closure implementation was undertaken once the

    mine shut down and mining operation ceased.

    In more and more jurisdictions, laws and regulations require that you prepare a mine closure

    plan as part of the basic process of evaluating the feasibility of opening a new mine and seeking

    mining permits. Some jurisdictions mandate regular updates of the mine closure plan during

    mining operations. Many jurisdictions now require posting of a bond or other form of financial

    security equal to the estimated cost of mine closure.

    Therefore, prudent and comprehensive mine closure planning now should occur at all stages of

    mine planning and operation. Depending on how you break up the phases of mining, it all boils

    down to consideration of mine closure engineering and financing as you evaluate the feasibility

    of the mine, proceed to detailed studies, open the mine, operate the mine, and approach


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    Thinking through mine closure as part of initial mine evaluation and planning has led to the

    concept of designing and operating the mine for closure - namely doing things from the very

    start in such a way as to make it easier and less costly to close the mine when mining

    operations cease. We shall discuss this issue in more detail as we proceed with the course.

    The Mine Closure Plan

    It is never too late to prepare a plan to close your mine. Most existing mines do not have a

    closure plan. The mine may have been in operation for many years and may have so long a

    remaining life that the idea of planning for closure is not an issue. Most mines begin operation

    well before the idea of preparing a mine closure plan as part of the mine's feasibility study,

    became necessary or fashionable.

    In recent times, however, the following and other realities have led to an increase in the early

    preparation of mine closure plans.

    An increasing number of jurisdictions have begun to demand a closure plan as part of an

    application to start mining.

    Shareholders have grown wary of the ever-increasing costs of mine closure and the impact of

    these costs on the profitability of the mining company. Prudent investors now seek information

    on the closure cost liabilities of a company in which they are considering investing.

    Taxpayers, burdened with the enormous costs of closing mines that have been abandoned by

    their owners, now demand that provision be made for bonds and other financial provision to be

    made, at the expense of the mining company, to close the mine.

    There is an increasing demand that mines prepare mine closure plans as part of the initial

    evaluation of the feasibility of the mine, part of the permitting process, part of ongoingoperation, and of course as actual mine closure approaches. In later sections of this course we

    will consider the contents of a mine closure plan.

    Financing Mine Closure

    Somebody has to pay to close the mine. Real dollars will have to be expended to pay the

    consultants, the contractors, and the mining company staff who will plan, manage, and

    implement closure. The issue is: where is this money to come from? If your mining company is

    large and successful, with other profitable mines, then you may simply draw on the overall

    company profits (reducing them, of course.) But if you work for a small company and the mine

    about to be closed is the company's sole or major resource, you may be severely cash-strapped.You may find yourself asking:

    Should you have provided a nest egg for closure?

    Can you draw on closure insurance?

    Should you go bankrupt and pass the cost to the taxpayer?

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    If you are the regulator of a new mine about to go into production, should you demand an up-

    front closure bond equal to the estimated cost of future closure?

    Engineering and Technical Approaches

    There is an enormous body of engineering and technical literature onthe details of mine closure. How do you select rock that will endure for

    the planned mine closure life? How do you regrade the site to resist

    erosion and subsequent geomorphic change? What vegetation should

    be planted, and how will this vegetation be replaced naturally by the

    climax vegetation of the region? This is where the specialists come in.

    In this course, we will not make you an engineering or technical expert

    in any of these areas, but we will set out the basics and the standards

    of practice that have been used at other closed mine sites.

    Social Issues

    Mines have been opening and closing for thousands of years. Some mines have opened, closed,

    opened, and closed a number of times as the price of gold, platinum, or silver has fluctuated

    along with economic fortune.

    Like taxes and death, mine closure is inevitable. People have flowed to new

    mines and left when the mines were forced into temporary closure or the

    resources were totally depleted. Temporary or premature closure is perhaps

    hardest on local communities: there is, so to speak, no final closure and lives

    and careers may be put on hold in the hope of the mine reopening. Folk

    working on and dependent on the mine in the event of mine closure are always asking: will themine reopen? When will it start up again? And, should we stay or go? This is true if the mine is

    "temporarily" shut because of either a prolonged strike or a genuine fall in commodity prices.

    On permanent, final mine closure, people know and can plan and act with some degree of

    certainty. Most will move to new jobs, new mines, or new cities. Hopefully there will be other

    sources of employment in the area and they can do what we would all rather do: stay in their

    homes, keep the kids in the same schools, and continue to be part of an established community

    of friends and family.

    In all instances in which a mine closes, temporarily or permanently, the mining company has alarge obligation to those affected and we discuss this in some detail in later sections of this


    It is not reasonable to demand that every closing mine leave behind a thriving industrial base. It

    is reasonable to demand that every closing mine leave behind a landscape where people may

    continue to live if they so choose - even if the money to live in the selected place comes from far

    away. In this course, we recognize the social implications of mine closure and the moral

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    imperative that the mine provide assistance and guidance to those left behind. So we will spend

    some time in later sections of this course on the issues of social interaction, sustainable mining,

    and the community relations techniques that are part of mine opening, operation, and closure.

    I base my approach to the social dimension of mine closure and the mining company's

    obligations in that regard on the following.

    It is good business practice for a mining company to do the right thing in regards to

    social obligations when it closes a mine.

    It is the right and moral thing to do to look to social justice when closing a mine - hence

    society is well within its rights to demand by way of law, regulation, and contract that a

    mine prepare for and implement its social obligations on mine closure.

    Most mining companies will not be able to pay for the social aspects of mine closure

    mitigation. Thus, society must demand and secure performance bonds adequate to

    cover the costs of those aspects of mine closure and its impacts.

    2 Types of Laws and Regulations


    This section looks at some of the many laws, regulations, and

    standards that govern mine closure in a number of places. The

    following is not intended to be definitive or exhaustive; it simply

    describes and discusses some of the laws, regulations, and standards in

    order to expose you to the diversity of approach to mine closure

    current in the industry.

    You will have to establish what the governing laws and regulations are

    that set the standard for closure of your mine. If there are no established laws and regulations

    you will have to decide which, if any, laws and regulations may be potentially appropriate. Only

    in extreme cases are you likely to be able to propose and implement closure standards of your

    own formulation. A mine in a location where there are no set requirements for mine closure is

    a mine in a distant, lawless place, and many other difficulties besides mine closure planning will

    be at the forefront.

    Types of Laws and Regulations

    A good law, rule, or regulation (the word regulation will be used in the

    remainder of this section) is easy to understand and enforce. Even

    better is a regulation that does not have to be enforced: people simply

    act in accordance with the spirit and letter of the regulation because it

    is so obviously the sensible thing to do.

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    A good regulation sets noble and achievable goals and leaves it to the person complying with

    the regulation to find the best way to achieve those goals.

    Regulations may be prescriptive or performance-based. For example, a prescriptive regulation

    tells you to put three-feet of clay with a hydraulic conductivity of less than 10-6cm/sec as the

    liner beneath your impoundment. By comparison, a performance-based regulation says:operate the impoundment so that is does not affect water quality - you prove to us that you are

    protecting groundwater quality.

    Prescriptive regulations inevitably fail to achieve the desired outcome. Prescriptive regulations

    fail because they stifle human ingenuity and technical innovation. At worst, a prescriptive

    regulation eliminates innovation and stops progress, leading to a net loss for stakeholders and

    the environment.

    UMTRA, INAC and Australian Standards


    The Uranium Mill Tailings Remedial Action (UMTRA) Project was undertaken

    to remediate inactive uranium mill tailings piles and the remnants of

    the mines and mills from which the tailings came. The sites, in excess of

    about fifty, are spread across the United States from Oregon to

    Pennsylvania, from Texas to the Dakotas. The Title I sites were closed by the

    Federal Government as the mines had produced product for the Manhattan Project. The Title II

    sites were closed by the private companies that had operated the mines to produce product for

    nuclear power plants.

    Closure was undertaken in accordance with a Federal law that established the following closure

    criterion: the closure works are to remain stable for 1000 years, to the extent reasonably

    achievable, and at any rate for 200 years.

    During the late 1980s and early 1990s, the engineering details that led to compliance with this

    criterion were worked out and implemented. We have now been able to observe the

    performance and examine the design of the closure works, which differed for Title I and Title II

    sites. The following conclusions were made.

    Admittedly, there is vegetation in many areas where vegetation was not anticipated. Admi

    infiltration barrier is greater than was initially estimated. But there have been no observations

    are susceptible to erosion, or that intrusion to or dispersal of the tailings is likely now or thr

    1000 years the covers will be well-vegetated as the climax vegetation flourishes in a rocky soil

    areas and covered with windblown sand in other areas.

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    The UMTRA closure standards are probably the most demanding. It costs a great deal to

    implement these standards, but they do lead to safe and effective closure - not walk-away

    closure, however. In Grand Junction, Colorado, there is a whole group of folk who regularly

    monitor the sites and undertake maintenance if required. The point is that even for such

    stringent closure criteria, there is no walking away. Somebody, some organization, some

    company, or the taxpayer will forever have to be there spending money to monitor andmaintain these sites.


    INAC (Indian and Native Affairs Canada) is charged with closing two

    mines in Canada, namely the Faro Mine and the Giant Mine. Both

    represent terrible failures by the regulators and the industry in

    preparing for closure. Both are costing the taxpayer infinitely more to

    close than they ever generated for the country and they are about to

    get only more costly. I was informed in late 2010 that a selectcommittee of experts is about to propose the following closure criteria for these two mines:

    prove that closure will be effective for 100 years;

    describe what will happen 1000 years after closure; and

    determine what will happen if global warming results in an average four degrees of warming


    This set of closure criteria is tantamount to adoption of the criteria that governed the Uranium

    Mill Tailings Remedial Action (UMTRA) Project: namely, closure to be stable for 1000 years, to

    the extent reasonably achievable, and at any rate for 200 years.

    In engineering practice, it is impossible to distinguish between the performances of a closed

    mine after 100 versus 200 years. The implication of the 1000 years post-closure period is that

    you have to provide for extreme events.

    We are now going to have to "prove" to the regulators that mine closure plans for mines in the

    cold parts of Canada will work and will be good for 100/200 years and for 1000 in the presence

    of four degrees of warming.

    Western Australia

    The Western Australia Department of Mines and Petroleum and the Environmental Protection

    Authority issued draft mine closure criteria in mid-2010. If adopted, these criteria will govern

    mine closure in Western Australia. The basic requirements are:

    reinstate natural ecosystems as similar as possible to the original ecosystem;

    develop an alternative land use with higher beneficial uses than the pre-mining land use;

    reinstate the pre-mining land use; and

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    develop an alternative land use with other beneficial uses than the pre-mining land use.

    In addition, site-specific criteria are required to:

    be specific enough to reflect a unique set of environmental, social and economic


    be flexible enough to adapt to changing circumstances without compromising


    include environmental indicators suitable for demonstrating that rehabilitation trends

    are heading in the right direction;

    undergo periodic review resulting in modification if required due to changed

    circumstances or improved knowledge; and

    be based on targeted research which results in more informed decisions.

    This all sounds well and good, but is very vague and flexible. Maybe that is exactly

    what is intended: provide the mining industry with the chance to select and do theright thing unencumbered by stringent regulations.


    At this link is a document on mine closure put out by the Australians. Here is what they say

    about mine closure.

    Plan, design, operate and close operations in a manner that enhances sustainable development.

    Consult with interested and affected parties in the identification, assessment and management

    of all significant social, health, safety, environmental and economic impacts associated with

    your activities. Inform potentially affected parties of significant risks from mining, minerals and metals

    operations and of the measures that will be taken to manage the potential risks effectively.

    Contribute to community development from project development through closure in

    collaboration with host communities and their representatives.

    State and Provicial Standards


    In Ontario the requirements for mine closure include "consideration" of four keyobjectives:

    protect public health and safety;

    alleviate or eliminate environmental damage;

    achieve a productive use of the land, or a return to its original condition, or an acceptable

    alternative; and

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    to the extent achievable, provide for sustainability of social and economic benefits resulting

    from mine development and operations.

    In undertaking your "consideration" you are required to think of the following


    Physical stability - buildings, structures, workings, pit slopes, underground openings, etc.

    must be stable and not move so as to eliminate any hazard to public health and safety,

    and to prevent material erosion of the terrestrial or aquatic environment. Engineered

    structures must not deteriorate and fail.

    Geochemical stability - minerals, metals and "other" contaminants must be stable - that

    is, must not leach and/or migrate into the receiving environment at concentrations that

    are harmful. Weathering, oxidation and leaching processes must not transport

    contaminants, in excessive concentrations, into the environment.

    Surface waters and groundwater must be protected against adverse environmental

    impacts resulting from mining and processing activities.

    Land use - the closed mine site should be rehabilitated to pre-mining conditions or

    conditions that are compatible with the surrounding lands, or achieve an agreed-upon

    alternative productive land use. Generally, the former requires the land to be

    aesthetically similar to the surroundings and capable of supporting a self-sustaining

    ecosystem typical of the area.

    Sustainable development - elements of mine development that contribute to (impact)

    the sustainability of social and economic benefit, post mining, should be maintained and

    transferred to succeeding custodians.

    Again, this sounds positive, but it is so vague as to be susceptible to manipulation by

    lawyers and corporate interests.


    The following are from the Nevada mine closure regulations and guidance


    When faced with hardrock mining reclamation, including closure, the authorized officer must

    ensure decisions will not result in unnecessary or undue degradation of the public lands.

    All actions must comply with the appropriate federal and state laws, and be consistent with

    BLM's multiple use responsibilities under the Federal Land Policy and Management Act (FLPMA).

    Reclamation decisions need to be coordinated and made in collaboration with the state

    regulatory agencies responsible for the permitting and oversight of mine reclamation, including

    closure activities.

    The BLM must ensure that activities such as long-term or perpetual maintenance of vegetation

    and/or wetlands, including monitoring, are provided for when these elements are part of fluid

    management or site stabilization. Fence maintenance, grazing management, weed invasion or

    increased salinity all impact vegetation at reclamation sites; consequently, these elements must

    all be considered in the long-term planning.

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    The BLM field specialists and managers need to understand and consider all the technical issues

    associated with hardrock mine reclamation, including closure activities and the long-term

    implications of closure, while ensuring that reclamation, including closure activities, is

    conducted in a timely and effective manner.


    All we need note about mine closure regulations in California is that they mandate backfilling of

    the open pit at closure. This seems reasonable if the objective is to eliminate above-grade piles

    that could erode. But backfilling of a pit is by no means a foolproof way to limit the generation

    and spread of contaminants, particularly in groundwater.

    Oil Sands

    The Alberta Energy Resource Conservation Board (ERCB) regulation for oil sands tailings

    disposal says that within one year of placement, the tailings should have a strength greater

    than 5 kPa, and ultimately the strength should be greater than 10 kPa. If the strength falls

    below those limits, you will have to scoop them up, take them back to the plant, and rework


    The underlying objective of the proposed ERCB regulations is noble: do not leave behind an oil

    sands tailings impoundment that consists of a well-engineered earth dike holding back fluid

    tailings. Presumably the regulators who wrote this proposed regulation want to avoid dike

    failure and flow of the impounded fluid-like tailings down the Athabasca River any time in the


    Wisconsin Mine Reclamation

    TheWisconsin Mining Information Fact Sheet: Reclamation and Long-Term Care

    Requirements for Metallic Mining Sites in Wisconsinbegins as follows.

    "Successful reclamation means the restoration of all areas disturbed by mining activities

    including aspects of the mine itself, waste disposal areas, buildings, roads and utility

    corridors. It is the product of thorough planning and execution of a well-conceived

    reclamation plan. Restoration means returning the site to a condition that minimizes

    erosion and sedimentation, supports productive and diverse plant and animal

    communities and allows for the desired post-mining land use."

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    Impending Regulations

    Impending Regulations

    In late 2005, the Montana Environmental Quality Council proposed the following requirement

    for a mine reclamation plan.

    The reclamation plan must conclusively demonstrate that, after... [two years] ...no

    treatment of surface or ground water for carcinogens or toxins will be required to meet

    water quality standards at the point of discharge.

    In early 2006, the Board of Environmental Review amended the language of the proposed rule

    to lower the standard of proof that water treatment would not be required beyond two years

    by changing the wording from "conclusively demonstrate" to "demonstrate by clear and

    convincing evidence." This was considered to reduce the 100 percent guarantee to a 70 percent


    In a study of the economic impact of this regulation, this conclusion was reached.

    As a result of adopting the proposed rule as amended in January 2006, an estimated 50 to 90

    percent of future metal mining economic output and 10 to 25 percent of future industrial

    mineral mining economic output in Montana would be prevented from developing... Overall,

    these two mining sectors comprise less than 1.5 percent of Montana's total economy in

    terms of jobs, wages, economic output and tax revenue. Therefore, the state economy as a

    whole would not be significantly affected by the proposed rule. However, mining's

    prominent history in Montana culture, its concentration in select counties, and the fact that

    mining jobs are high-paying, would ensure that localized, significant effects would occur.

    The proposal was tabled indefinitely when the Montana Department of Environmental Quality

    came out against it. The bill in Idaho has been referred to a committee for further study.

    Some General Observations

    The brief, previously discussed survey of the great variety of mine closure criteria illustratesthat there is no one generally accepted approach, either in law or practice, to mine closure. As

    we noted in the introduction to this section, find out what is applicable to your mine, do it, and

    adjust to get a cost-effective approach.

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    3 Post-Closure Mine Use

    Sustainable Mining


    Most laws and regulations on mine closure provide sufficient flexibility to formulate a site-

    specific post-closure use of the closed site. Obviously, closing the site by surrounding it with a

    high security fence is the easiest, cheapest, and least liability-prone approach. However, with a

    bit of ingenuity and thought, better uses may be found for closed mine sites. In this section we

    will discuss some options in the hope that this approach may become a little more common

    than it is.

    Sustainable Mining

    If the concept of "sustainable mining" has any utility, it is surely withregard to the planning and implementation of a productive post-

    closure use of a mined-out site. It is superfluous to invoke the concept

    of sustainable mining as the basis for saying the mine should not

    pollute the surrounding region after closure. It is redundant to invoke

    concepts of sustainable mining to plead that there should be

    employment post-mining for the miners whose jobs disappear when

    the mine closes.

    Only a productive use of the closed mine site can be said to constitute "sustainable" mining.

    Even that statement fails to pass the parsimonious test: it is enough to simply say that it is good

    and proper to put the closed mine site to beneficial use.

    What constitutes "beneficial use" is a site-specific matter. In the middle of a distant desert, the

    closed mine may be best left to go back to dry wilderness. A mine close to a densely populated

    area may open up space for recreation. Let us consider some of the options, primarily by way of

    a review of case histories.

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    Case Histories and Landfills

    Case Histories

    East Geduld (South Africa)

    One of the many deep gold mines on the East Rand of South Africa,

    East Geduld operated for over fifty years. When I was growing up, my

    father, who was Mine Captain on the mine, often spoke of his concernthat the mine would close and we would have to move on. But more

    and more gold was found, and technology advanced to enable the

    miners to go deeper and further. The mine endured for many years

    after we moved away. Only a few years ago did I read that the mine

    had finally been closed.

    A quick search via Google Earth showed that the mine houses where we grew up were still

    there. The area where there had been a shaft and mill is completely changed: now there are

    big, secure buildings - a plant that makes artificial diamonds. The slimes dams are gone:

    reworked to recover residual gold and uranium left behind in the first processing. The area isgreen, taken back to fields.

    The Witwatersrand (South Africa)

    Much the same has happened to many of the old gold mines of the

    Witwatersrand. This mining area gave rise to a dense urban

    concentration. Some sixty percent of the population of South Africa is

    said to live along the Witwatersrand gold belt. Johannesburg is the

    major city that was founded to support the mines and which grew to

    financial dominance serving the mining industry.

    With closure of so many mines in this part of the world, the regional groundwater table is rising

    to its former level. Mining over more than one hundred years resulted in a significant

    depression of the groundwater level. As the mines went as deep as 6000 feet, the miners

    pumped out the water that flowed into their mines. The water table dropped, and sinkholes


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    Now the water level is rising and much of the water is contaminated; some is acidic and may

    one day flow into surface creeks and streams. What to do? This is under study, and represents

    as great a mine closure challenge as any anywhere in the world.

    In theory, the issue of groundwater fall and rise as mining rose and fell could have been

    addressed as just another project in mine closure planning. In practice, the history and courseof mining along the Witwatersrand did not allow this to be. The mines began well before

    modern theories of mine closure were formulated. The mines were owned by many competing

    mining companies. The effects were cumulative and additive. The focus of the times was on

    technology and maintenance of white supremacy.

    Yet, perusal of this case history alerts us to the benefits of comprehensive planning by the

    mines and by the regulators of these areas in which many mines occur. Comprehensive

    planning should include detailed consideration of closure of the individual mines and the total

    effect on the areas in which the mines congregate. Similar situations occur today in the coal

    fields of America, in the copper mines of Chile, and the oil sands of Alberta. Let us hope that

    focus on closure of individual mine components, here an impoundment, there a waste rock

    dump, over there a disturbed creek, do not distract attention from the bigger, regional-wide

    issues of mine closure.

    For this course, all we can do is bring your attention to the issues, and advise that in planning

    closure of your single mine, you give at least a passing thought to the bigger issues of closure of

    all the mines that occur in the region of your mine. You may not succeed, even when achieving

    your best, if others in the region fail.

    Cannon Mine, Wenatchee, Washington

    The Cannon Mine was a gold mine that opened in the early 1980s southwest of Wenatchee,

    WA. The tailings impoundment included an initial 100-m-high rock-fill embankment,

    diversion channels, and hydraulically discharged tailings. With time, the embankment was

    increased to 140 m high. The impoundment was operated successfully for the life of the mine,

    and when mining stopped, the impoundment was reclaimed.

    Today the reclaimed site is fully integrated into the surroundings and a good example of mine

    closure that can be successfully undertaken close to urban areas. By 2001, county and state-

    held bonds were released and in 2003 the impoundment (or at least those who undertook its

    closure) was/were the recipient(s) of the Washington Department of Natural Resources

    "Recognition for Reclamation Award."

    Here is what you can read at thislinkon the current use of the site:

    It's been called many things over the years: the Cannon Gold Mine, the Asamera Mine, the

    holdings of Conoco Phillips, the property purchased by the Appleatche Riders. Now the land

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    that borders Saddle Rock to the south and that was part of a mining operation until 1994 is

    known as the Dry Gulch Preserve. The property, which was once part of the second largest

    gold operation in the United States, was purchased from Conoco Phillips in 2007 with the

    provision that the Land Trust would hold a conservation easement to it. This provision

    prevents this 700-acre parcel from ever being developed and will keep the heavy-metal,hazardous-waste nasties leftover from the mining days permanently buried.

    The Appleatche Riders wanted this property adjacent to their riding club for obvious reasons:

    it gives their 650 members immediate access to a tremendous amount of terrain for riding

    horses. After acquiring the property, the riding club quickly created a limited partnership,

    called the Dry Gulch Preserve LLC, which holds and manages the property.

    Despite the jokes about the toxic residues that are capped off and buried here, having so

    much open space that is so easily accessible is a tremendous asset to Wenatchee residents.

    About 8 miles of dirt roads and trails on the property provide places where you can walk, jog,

    run the dog, and horseback ride (no motorized vehicles or mountain bikes allowed). The areastill shows the scars from its mining past, but there are surprisingly pretty places on the

    property. Some of the high ridges and slopes are thick with blooming flowers in spring. And

    many overlooks provide solid-gold views of the Columbia River Valley.

    Let me end this story simpy by posting several pictures of the tailings impoundment after

    closure, and one of the area which is now a riding stable.

    Britannia Beach, British Columbia

    A short drive up the coastal road from Vancouver is the Britannia Mine. When the mine first

    started, it took a twelve-hour boat ride up rough seas to get there. But it was worth the trip, for

    this was one of the largest copper mines in the world. Here is the basic story.

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    In 1888, Alexander Forbes, an enterprising doctor from Scotland, arrived in Vancouver. Eager

    to make his fortune in the local area, he met with prospector Granger who showed him some

    promising rock samples. On a trip to the Howe Sound area to research further, Forbes shot at

    a buck deer and the deer's flailing hooves exposed some mineralized rock below the moss. As

    they cleared away the undergrowth, Forbes and Granger discovered what was soon to

    become one of the largest deposits of copper in the world.

    The miners drove tunnels deep into the towering hills beside the sea. They brought the ore out,

    crushed the rocks, and dumped the tailings into the inlet to form the flat area where the

    highway now goes. But the copper ran out, mining costs increased, and the mine was shut.

    Low copper prices and the lure of the city life soon saw the Britannia Mining & Smelting

    Company reduced to seven employees, and in 1959 it went into liquidation. In 1963 the

    Anaconda Mining Company bought the property. A new ore zone and a new contract for the

    miners saw increased production for the next eleven years. Operating costs and taxes rose

    and eventually the mine was shut down on November 1, 1974. Fifty-five men went

    underground on the last shift as the whistle blew a three-minute requiem for the Britannia


    Now the site is a museum where tourists stop to enjoy a trip down mining memory lane. The

    area has been well reclaimed. The old mill has been restored. This is a good example of what

    can be done on mine closure, although the water treatment plant will probably have to be

    operated forever. That is not, however, what the museum's publicity proclaims; instead they

    say this:

    During the seventy-year life of Britannia Mines, 60,000 people of many races, languages and

    religions, worked and made their homes in the area. In 1975, the Britannia Mine Museum

    was opened to the public, and in 1988, Mill 3 was designated as a National Historic Site. Thefollowing year, the Museum site was designated a British Columbia Historic Landmark.

    Leadville, Colorado et al.

    Leadville, Colorado is an example of an old mining town that turned itself into a mining

    museum. Need more be said?

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    Half the towns in the Colorado Rockies are the remnants of mining. They, like Britannia Beach,

    are fortunate to be in beautiful mountains, but the fact remains that the towns are there

    because of mining; call it sustainable development if you will.


    The old Victory mine site in Indiana was reclaimed to productive use. Here is part of a press

    release on the closure.

    "What other abandoned mined land site can boast of being an operating landfill, a growingcommunity recreational center, the site of a world championship racing event, and the site of an

    NCAA Championship event? The reclaimed Victory Mine Site was once a barren and eroded

    abandoned mine refuse area that created sedimentation and acid mine drainage problems in an

    adjacent stream. The site was also used as a trash disposal area for years and an open mine

    entry presented a hazard to human safety. Today the site is a major community recreation area

    and the location for local, national, and world sports events. The site has come a long way in the

    last few years and the story is remarkable."


    In Huntington Beach, one of those beach cities hugging the coast of Orange County, California,

    there was once an old quarry just outside of town. It supplied the rocks, gravel, and sand to

    build the town which grew to surround the quarry. The city fathers decided to fill the quarry in

    by using it as a landfill and so for many years the Gothard Street landfill was a stinky part oftown. Today the filled landfill is landscaped and covered with playing fields where every day

    and evening there are contests of basketball, soccer, and baseball. It is now in the center of a

    wealthy urban area and a nice place to recreate.

    Eagle Mountain is an old mine on the eastern border of California. A large company sought to

    turn it into a landfill. For years, they did the right things politically, including talking to the

    locals. They failed however, for local opposition was too strong.

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    Then there is the Mesquite Mine in south-east California. Los Angeles is running out of landfill

    space. So they have built a huge landfill on the old Mesquite mine property and truck the waste

    many hundreds of miles to the landfill. In due course, the waste will be transported there by

    rail, and for the next thousand years the old mine will be the landfill of Los Angeles and

    surrounding communities. They are not filling the pit with waste; the mining company still has

    hopes of re-opening the open pit and going back into production.

    4 Mine Closure Phases, Planning and Implemetation

    Phases of Mine Closure


    Different philosophies and hence technical approaches to mine

    closure are applicable depending on both:

    the reason for and the nature of mine closure; and

    the stage of mining when you are undertaking mine closure


    In this section we discuss the various stages or reasons for mine closure. We distinguish

    between interim mine closure, temporary mine closure, premature mine closure, and closure at

    the end of mine life. We spend a bit of time on the reasons for undertaking such closure and

    give some guidelines on the main things to be done in the event of such closure.

    Interim Mine Closure: Design and Operate for Closure

    Interim mine closure is also sometimes called: design and operate for closure. Or: undertake

    operations in such a way that you close facilities as operation proceeds. The idea is best

    described with reference to mine development and the operation of mine waste facilities, as


    Reclaim disturbed areas as soon as possible after disturbance.

    Establish new wetlands and permanent ponds as soon as you can.

    Operate the waste rock dump in such a way that you can close those parts of the dump that are

    no longer needed.

    Revegetate tailings impoundment slopes as the height of the slopes increases.

    Place soil covers over parts of the impoundment surface that will no longer receive deposition.

    Close heap leach pads once used, and as you move on to new heap leach pads.

    The basic idea is simple: lay out the mine and the waste disposal facilities so that they are

    quickly, easily, and cheaply closed. Thus, place acid-generating rock in the middle of vast piles

    of neutralizing rock; create flat slopes on waste rock dumps; and progressively construct covers

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    on the tailings impoundment. Ideally, filter press and hence dry stack your tailings even if you

    have lots of water available.

    Design and operation for closure and the attendant implementation of interim closure may

    save shareholders and taxpayers lots of money. It makes for fine conference presentations. In

    practice, it is seldom used. The sad fact is that it is generally more profitable to use thecheapest approach to mining, to maximize present profits, and defer the costs of closure to


    Temporary Mine Closure

    The reasons for temporary mine closure are many. A bitter strike has led to temporary closure

    on many mines. The economic crashes of the early 1980s and of 2008 caused mines to close.

    The price of gold, silver, and other metals fluctuates in response to market forces. The ore

    grade may fall below the profitable mining grade. The mining technologies of the time may be

    inadequate to extract the ore. So the mine closes. But prudent folk know the mine could bereopened if conditions change. The mining company that owns the mine may decide not to go

    for full closure and all that that means, including construction of the final closure works.

    A comprehensive mine closure plan will provide for temporary mine closure. The work

    undertaken in the event of temporary mine closure varies depending on the anticipated interim

    closure period and the reasons for temporary closure.

    Obviously there are some things that have to be done during a temporary closure, such as:

    maintenance of security facilities;

    upkeep of offices and plants that will be needed on reopening; operation of water treatment plans and other facilities to ensure compliance with

    environmental protection needs;

    ongoing monitoring of air and surface and groundwater quality as part of permit


    liaising with the regulators to keep them informed and supportive of ongoing efforts to

    maintain the mine and to reopen it as soon as is practical;

    supporting affected workers who may be retained, relocated, or otherwise helped to

    find other jobs at other mines; and

    integrating with the community so that they understand what is going on and what your

    intentions are. As for any aspect of mining, the community relations folk on the mineshould be fast and proactive in telling community leaders and all potentially affected

    that the mine is about to be temporarily closed, explaining why this is necessary, and

    seeking to impress on them that the mine will be cared for and kept in a condition that

    promotes and facilitates reopening when times improve.

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    Premature Mine Closure

    Temporary mine closure implies a commitment to reopen the mine as soon as reasonable and

    cost-effective. Closure at the end of mine life is usually an event that is well anticipated and

    which may be planned for over a long time. Conversely, we define premature mine closure as

    that most unfortunate event when a mine is humming along and all of a sudden, out of theblue, something happens and it is necessary to shut the mine down knowing that it is not

    intended to be reopened.

    The "somethings" that lead to premature mine closure can include;

    world-wide economic crashes as occurred in the early 1980s and in 2008;

    a collapse in the demand for the product mined; resulting, for example, from a regulation that

    discourages use of the product, such as some grades of coal;

    a flood, such as the one that occurred in Australia in late 2010 and early 2011;

    breaching of a geological dike and a sudden rush of water into the underground mine workings

    such as happened at Cigar Lake in 2006;

    a fire in the mine or the plant resulting in the realization that it is just not cost-effective to

    rebuild the fire-destroyed works; or

    a change in the government, with the new government seizing the mine as part of political

    change - this happens too often in Africa.

    Regardless of the root cause, premature mine closure usually happens rather suddenly; closure

    planning may not be in place to address the issues, and the money is just not there to pay for

    full closure.

    A good and comprehensive mine closure plan should include consideration of premature mine

    closure. But it is not always possible to identify the myriad of things that may lead to this event.

    It is unlikely that even comprehensive mine closure planning will be able to anticipate the

    infinite variety of conditions at the mine that may be associated with premature mine closure.

    Those left behind will undoubtedly have to scramble. Here are a few things they may need to

    focus on.

    First: take action to help the employees who are affected. Actions may include helping them

    find new jobs, letting them remain on the payroll just a little longer, and providing for closure of

    their careers on this mine.

    Second: communicate with the community affected. Let them know what you know; reassure

    them that you are planning to close the mine responsibly; help them to adjust where you can. Third: work with the regulators to ensure orderly and rational closure works construction, even

    though this may mean a substantial change of approved closure plans and designs.

    There will be instances where this cannot or will not be done. The closure is too sudden; the

    causative event too disruptive; and the money is just not there. This is the tragedy of mine

    closure that bonds and financial assurance is intended to deal with. (These topics are discussed

    later in this course.)

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    Somebody somewhere will dust off the Closure Plan, if there is one, curse their luck at having to

    implement the plan with zero budget, and wonder about multiple trips to haggle with fussy

    regulators unwilling to free up closure bonds.

    Some lawyers and accountants will meet in secret to deliberate the benefits of going bankrupt.

    The outcome will depend on the size and reputation of the owning mining company. If a smallcompany, there is a good chance that bankruptcy will be the better course. If the company is

    large and well-known, they will swallow hard and seek to delay closure costs for as long as


    As a regulator, you will have to recognize that you have the nigh-impossible task of forcing

    implementation of the approved Closure Plan, if indeed there is one.

    Temporary Closure Case History

    Here is a rather sad story of temporary closure of an Australian mine.

    Unionists say the temporary closure of Tasmania's Mt. Lyell copper mine has forced many

    workers onto social security benefits. Copper Mines of Tasmania shut down its underground

    mine at Queenstown a month ago, after heavy rain caused a mudslide. It initially expected to

    have the problem fixed within days but the company now says it has no clear timetable.

    About 180 Barminco underground mining contractors were required to take paid leave while

    remedial work is carried out, but Rob Flanagan from the Australian Workers Union says many

    of those have already used up all their leave. "Within weeks, 140 will be on social security

    payments. There have been substantial royalties that the people of Tasmania have had as abenefit of Mt. Lyell, and it's at this point in time when the employees who have contributed

    to that need the help of the people of Tasmania," Mr Flanagan said.

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    Closure at End of Mine Life

    The end of mine life inevitably happens; there simply is nothing left to mine. The event may

    have been long-anticipated and long-planned-for. An orderly process of interim closure may

    have been going on for some time. All that remains is to implement the final phases of closure

    as well as described in the approved Mine Closure Plan.

    This is the happy, orderly situation. There is time for the following, all of which should be

    spelled out in the Closure Plan.

    orderly reduction of staff to meet the reducing and changing needs for mining, processing,

    monitoring, and construction of closure works

    constructive interaction with the community, which has become used to the idea of mine

    closure and had had time to prepare and adjust

    calm and professional interaction with the regulators who have approved what you now set

    about doing - there are no surprises, no pleas for last minute changes, and no agony over

    promises made and broken the accountants are quiet, for there is money to close the mine, bonds are adequate, and upper

    company management is not breathing fire down innocent necks

    constructing the promised new golf course, community center, recreation facilities, riding

    stables, and hunting grounds

    tours by journalists around the closing and closed site, who come away with lots of good press,

    and the mine receives awards for a good job done thoroughly

    Post Closure Care and Maintenance

    Once the closure works are constructed, post-closure care, monitoring,

    and maintenance begin. It goes almost without saying that such

    activities are undertaken in accordance with an approved plan.

    Sometimes the plan is called the Post-Closure Monitoring and

    Maintenance Plan; sometimes it is called the Surveillance and Monitoring Plan. Regardless of its

    name, the plan will set out roles and responsibilities, standard operating procedures, reporting

    obligations, and funding provisions.

    To my knowledge, at most closed mines, a small team of people remain to undertake these

    activities. The need for on-site staff post-closure is generally a result of the need for ongoing

    water treatment. On-site staff may be needed to mow the grass, keep planting trees, maintain

    fences, fix erosion gullies, and undertake groundwater-well monitoring and reporting.

    If the site has truly been closed to remain stable in the long term and water treatment is not

    involved, post-closure work may be undertaken by folk living far from the mine. On the UMTRA

    Project, those charged with post-closure surveillance and maintenance operate from Grand

    Junction, Colorado; they visit sites at regular intervals to observe general conditions and to

    decide if any maintenance is required.

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    In practice and in theory, post-closure surveillance and maintenance will be required forever at

    sites that are not turned over to another group for beneficial use. Only if the closed site is

    transferred to another group who makes beneficial use of the site, may we talk of "walk-away"

    by the mining company. Thus, the rights to use the site as a race-track, riding stable, or hunting

    ground may include the responsibility to maintain the site.

    Closure Plans


    Now that we have a good idea of the possible types of mine closure, or at least the reasons why

    mines close, let us proceed to the issue of mine closure planning. My approach is based on the

    simple rule of good management: plan the work, and work the plan. Ideally, you will prepare a

    mine closure plan at the earliest possible time in mine evaluation and planning. Hopefully you

    will update the closure plan as you advance to start of operations, and you will definitely

    continuously update the plan as mining is undertaken.

    Mine Closure Plans

    Some mine closure plans are required by law, some are prepared as a matter of good planning

    and management, some are prepared as part of evaluating and permitting a new mine, some

    are prepared while the mine is in full-scale operation, and some are prepared long after actual

    mining has ceased.

    There is no such thing as a generic mine closure plan. As we have seen, mine closure practice

    varies immensely: a new playing field on the flattened site of a mountaintop mine in Virginia isvery different from a new diamond plant on a mine in South Africa, which is very different from

    a restored arboreal forest in the coldest part of Northern Canada.

    Some jurisdictions mandate the contents of a mine closure plan. Examples include Nevada and

    Western Australia. Some regulators come to expect a certain format from the consultants

    working in the area. Regardless, here are the minimum contents of a mine closure plan:

    roles and responsibilities;

    mine description: region, site, mine, plant, and waste facilities;

    closure engineering and technical plans: interim, temporary, premature, and final;

    post-closure surveillance and maintenance;

    financial mechanisms and assurance;

    employee impact mitigation; and

    community engagement.

    Here is a different take on the contents. It is from a paper by D.R. Welsh (Welsh (2007))(bullets


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    The key elements of a mine closure plan that should be specified in regulations include:

    a project description;

    details of the operator and mining tenement holder;

    background information about the existing environment;

    actions for making the site safe including the decommissioning and dismantling of theplant and buildings and closure of underground works;

    rehabilitation of all disturbed areas;

    arrangements for the workforce;

    proposals for community engagement;

    proposed research to drive improvement;

    closure implementation including schedules, review process and environmental

    monitoring; and

    cost estimates.

    A mine closure plan may be part of - or an adjunct to - one or more of thefollowing:

    a mine feasibility study;

    an environmental impact statement preceeding opening of the mine;

    a Mine Operating Permit;

    an application to a bank or other lending institution for funding to open or expand

    the mine;

    the NI 43-101 (or equivalent) documents as issued to support company listing or

    other stock exchange regulations and requirements; and

    a Record of Decision on closing a mine.

    Clearly, the amount of detail in the plan will vary depending on the phase of mine planning

    and/or operation and the primary purpose for which the plan is intended.

    On the basis of the good management principle of Continuous Improvement, we recommend

    that the mine closure plan be updated regularly. Times change, circumstances change, mine

    operations advance, monitoring reveals new truths about impacts, and people come and go. It

    is necessary and prudent to update the closure plan at least every two years and whenever

    there is a significant change in operations or impacts.

    We will now consider some of those phases of mining that influence the nature and extent of a

    mine's closure plan.

    Closure Planning

    Here are recommendations by Dave Bentel included in a presentation at the University of

    Nevada (Bentel (2007)).

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    Step 1: Closure planning database - develop a site closure database/library (i.e. existing,

    technically valid data that characterizes site conditions potentially influencing, or potentially

    influenced by, mine closure). Initial planning is performed using available data only (i.e. no

    additional characterization until it can be justified by the process).

    Step 2: Identification and preliminary classification of site facilities - identify and

    document all site facilities. Based on available operational data and physical inspection,

    classify into facility types that may require similar closure actions, e.g. gold heap leach

    facilities, waste rock dumps consisting of similar waste rock types, tailings disposal facilities,

    pits with lakes, dry pen pits, crushing and milling process plant facilities, buildings,

    infrastructure, etc.

    Step 3: Documentation of site conditions affecting closure- document known and baseline

    site conditions based on data research and physical inspections for: existing facilities;

    anticipated facility status at closure; groundwater resources; surface water resources; air

    quality; physical and geochemical characteristics of process and waste materials; chemicalcharacteristics and flow rates of site waters requiring management; climatological

    conditions; site soil and erosion potential; potential closure borrow sources; site vegetation;

    and avian and terrestrial wildlife.

    Step 4: Site regulatory analysis- identify regulatory closure criteria. Analysis must cover all

    pertinent regulatory bodies and regulations.

    Steps 1 to 4 are the least you should do. Steps 5, 6, 7, and 8 may be undertaken depending

    on corporate policy.

    Step 5: Stakeholder analysis - identify existing and potential stakeholders and perform a

    site stakeholder analysis to document potential and existing stakeholder issues. Develop

    criteria to address these issues.

    Step 6: Corporate and site management criteria- identify corporate and site management

    goals (overarching goals) for closure, including financial and cash flow reporting

    requirements and asset preservation strategies.

    Step 7: Closure impact assessment - use criteria previously identified to assess potential

    impacts of closure to health, safety, environment, and community.

    Step 8: Risk assessment- develop a site closure risk register that: identifies and ranks risk

    issues resulting from potential impacts; identifies risk issues that require risk management

    to appropriately reduce the zero-base ranking; and develops risk management criteria.

    Step 9: Conceptual closure design - develop conceptual engineering options that provide

    solutions that, at a minimum, address conceptual design criteria and risk management

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    Step 10: Basis of cost estimate- develop a basis of cost estimate that provides detail of how

    quantities are measured and how unit rates are obtained.

    Step 11: Cost estimate - develop cost estimates that meet corporate financial reporting

    criteria. Compare capital and operating costs for each conceptual option.

    Step 12: Residual risk assessment - use the risk register to demonstrate that the closure

    options selected provide appropriate risk reduction. Evaluate the relative risk reduction

    benefits for each option.

    Step 13: Optimization of conceptual design - select and cost the conceptual closure design

    options that are judged to best meet criteria and risk reduction goals.

    Design and Operation

    Site and Region Characterization

    An early activity associated with most modern mining is characterization of the site and region

    of the mine. This is not the place to go into the details - they are well addressed in other

    EduMine courses such as Geotechnical Engineering for Mine GeoWaste Facilities,

    Groundwater in Mining,Surface Water Management at Mines,andMine Water and Chemical

    Balance Analysis.At this stage of mine evaluation you should collect as much information as

    possible about the pre-mining conditions at the site and in the surrounding area. Gather data

    about geology, geomorphology, stream flow, groundwater, naturally occurring constituentsthat later regulators may brand as contaminants, and the lives and histories of those who have

    and do now live around the area of the proposed mine.

    To emphasize this advice, here is a case history. Some forty miles east of San Francisco is an old

    mine. It operated for about five years and never made a profit. Then it was closed.

    The site is beautiful: green grasses covering rolling hills, contented cattle and deer roaming the

    golden rises, a lake of tranquil waters behind a solid embankment, views of the distant hills and

    fields, and flowers in full bloom. You can see why the wealthy come to snap up the surrounding

    properties and commute to well-paying jobs in San Francisco.

    The mine has been "in closure" ever since it ceased mining. Millions have been spent on

    lawyers, lobbyists, consultants, and actual works to make dilution the solution. It will never be

    "closed" in the sense that people can never walk away and the area will never "perform" as

    part of nature and not affect downstream folk.

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    The early history of the site is well documented in Brian Fagan's book Before California: an

    Archaeologist Looks as Our Earliest Inhabitants. He chronicles the inhabitants of the area who

    came to gather acorns and salt. Before the mine was developed, massive graves had to be

    excavated and moved. This provided the archaeologists with the information set out in Fagan's

    book: the ancients came for salt because a fault which contained gold forced salty water to the

    surface. The ancients gathered the salt and the acorns of the surrounding woods.

    The miners failed to adequately characterize background conditions before mining. Salt

    continues to emerge and flow from the site. The mine's claim that this is background has never

    succeeded with the regulators, who see salt turning downstream golf courses white and crusty

    and respond to the folk who commute to San Francisco and demand only pristine, salt-free

    water from the site.

    Thus, for decades since mine closure, more has been spent than ever was earned by the mine.

    Expenditure in pursuit of clean water releases will be a never-ending goal of regulators and

    wealthy downstream land-owners. The original mining company has been taken over by a

    foreign company and they grow tired of such expenditure. They have engaged new consultants

    to evaluate the long history of high post-closure expenses and to tell them how to stem this

    never-ending bleed of money.

    The simple answer is to put about $12 million in an interest-bearing account at, say, three

    percent, and continue forever to manage the site and send water downstream that does not

    affect local golf courses, rivers, farms, and ultimately the ocean.

    Feasibility Stage Evaluation

    If you are evaluating the feasibility of opening a new mine, you will surely have to prepare an NI43-101 or equivalent document. Such documents are required these days by almost all stock

    exchanges where shares in mines and mining companies are traded. The details of such

    documents vary from jurisdiction to jurisdiction, but they all have a common aim: tell potential

    investors why this may be a viable and profitable mine. So, set out the data, including costs,

    thus enabling prospective investors to make up their own minds about the risks and rewards of

    buying shares.

    Obviously there is a real cost associated with closure of the mine. It is going to cost you to post

    closure bonds and make other financial provisions for closure. These closure-related costs may

    well affect the financial viability of the mine. Potential investors must be told, for otherwisethey may have a valid claim for fraud or suppression of information.

    Formulate at least a preliminary closure approach and make at least a preliminary assessment

    of potential closure costs.

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    If you are a consultant engaged to do this, my best advice is to overestimate closure costs. Such

    costs never seem to go down, but always increase and increase. No point in having to go back

    later and admit you underestimated costs.

    If you are working for the mining company, you may choose to minimize closure cost estimates.

    You will probably have retired by the time the true, higher cost is confirmed. The lower costestimate will reduce the cost of the project, thus pushing up the value of the project and hence

    share prices.

    If you are a potential buyer of shares, the previous advice, different depending on who

    prepares cost estimates, should be sufficient to warn you to be skeptical about closure cost

    estimates in NI 43-101s and similar. The estimates are probably all way off. What you have to

    decide as a potential investor is: which way does the inaccuracy lie, and how does this bias

    affect the value of shares now and in the future? In brief, you should ask: can I sell the shares

    before the implications of closure costs drive share prices down?

    Design and Operation

    You are the engineer charged with preparing mine design and operations plans. In the spirit

    that you can and should plan and operate for closure, we recommend that you persist through

    this course to the section of the technical aspects of mine closure. Be aware of them,

    understand them, and seek to avoid or