Mining is an economic activity that has been occurring for hundreds, and in some cases thousands of years, while the planning for mine closure is one aspect where historic practices and evolving community expectations are just beginning to merge.

Mine closure has become a topic of industry, government and community discussion over the past 20-25 years during which time the institutional and legal frameworks that govern the practice of mine reclamation have evolved in response to changing public expectations.

In 1987, the Brundtland Commission resulted inter alia in the well-known definition of sustainable development namely, development that meets the needs of the present without compromising the ability of future generations to meet their own needs.  The Brundtland report provided material for environmental groups, pressure from which has resulted in a more vocal public demanding that governments create stronger legislation to compel the mining industry to be more environmentally sensitive.

In June 1991, an International Round Table Conference on Mining and Environment was organized in Berlin.  Although mine closure was not broadly discussed, the Berlin Guidelines provided an initial outline of "necessary environmental guidelines and strategies on mining with emphasis on developing countries".  In many countries, environmental impact assessments, now required by law, are the vehicle under which companies are required to produce a detailed closure plan.

In 1992, United Nations Conference on Environment and Development (also know as the Rio Conference) resulted in Agenda 21, the programme for environmental management for the 21st Century.  It emphasized the need to adopt environmental guidelines for natural resources development.  Since 1992, the United Nations Environment Programme (UNEP) and other international agencies have been providing environmental guidelines for the minerals sector.

In 1994, an International Conference on Development, Environment and Mining was co-sponsored by the World Bank, UNEP and the International Council for Metals and the Environment (ICME).  The purpose was to share ideas, perspectives, information and solutions with respect to the challenges surrounding sustainable mineral development.  Key conclusions, inter alia, were that:

• Environmental regulations do not act as a disincentive to investment provided that the regulations are realistic, transparent and stable;
• The objective of rehabilitation of mine sites should be to restore them to a self-sustaining ecosystem that is as close as practical to its original state prior to mining activity.  There is a need for mechanisms that ensure the availability of funds to finance rehabilitation; and
• Principles of environmental management are being adopted by industry and these are seen as a vital part of efforts towards continuous improvement.  The management systems being adopted depend on regulations and on corporate cultures.  These systems are part of the industry's efforts to demonstrate that mining is compatible with environmental protection.

In 1997, the UN Division of Economic and Social Affairs (DESA) and UNEP compiled Environmental Guidelines for Mining Operations and discussed approaches to implementation, monitoring, enforcement and participation.

In 1998, UNEP produced Case Studies on Tailings Management in partnership with ICME.  UNEP also developed a training manual on Mine Rehabilitation for Environment and Health Protection: A Training Manual with the World Health Organization to introduce mine personnel to new skills - information and training are at the heart of any new approach.

In November 1999, a second Mining and Environment Roundtable was held in Berlin which resulted in the Berlin II Guidelines including a major section on mine closure planning and rehabilitation which can be viewed in three stages:

1. the Planning stage where the rehabilitation plan is established as an integrated part of the site's environmental management plan and regularly updated;
2. the Active Care stage which immediately follows the cessation of activity; and
3. the Passive Care stage which covers the period of sampling and monitoring to ensure that the active care stage was sufficient to allow those originally responsible to "walk away", recognizing that in some cases that may never be possible.

Environmental Liability and Site Rehabilitation

Because every phase of the mining sequence involves some degree of ground disturbance, the objective of site remediation is to rehabilitate the entire site first, to protect public health and safety and secondly, to return the site and its surroundings to economic use and/or a sustainable ecosystem.  In many countries with low rainfall, the tracks and scars of exploration covering many square kilometers of land that may never be mined remain a long time.  However, techniques can now be used to reduce the extent of disturbance although some rehabilitation will always be needed.

During mining operations, much ground is exposed to the elements  Closure involves inter alia sealing underground mines and rehabilitating, regrading, stabilizing and revegetating open pit operations, and rehabilitating waste dumps including tailings dams.

New operations try to minimise land disturbance, plan for soil and waste storage, and undertake progressive revegetation and land management.  In fact, experience has demonstrated that a well managed mine that follows strict environmental stewardship principles throughout its operations will usually be easier and less costly to ultimately close and reclaim.  A key issue is where, when and how to dispose of mine spoil, tailings and other mine waste so that these operations are safe, have a minimal environmental impact now and in the future as well as improving the aesthetics of the site.

Following closure, the mine site needs to be restored to some predetermined plan.  Today, the more progressive mining companies start planning for closure before the first operations commence so that the costly need to re-handle material, reshape landforms and restore degraded environments at the last moment is minimised.

Today, there are many mine sites however, where the damage has already been done, meaning that post-project rehabilitation is required.  These situations are invariably expensive, often with no clear view of where the necessary funds will come from as the economic phase of the mine is past.  Post-project rehabilitation must be practical and cost-effective.  In many cases, the primary objective will be to make a site physically and chemically secure rather than planning for a productive after-use.  Time may be one of the tools relied upon to do over many years what technology and intensive care could otherwise achieve in a few months at more active sites.  While this approach is neither ideal nor recommended, it is a minimalist approach and is better than just "walking away".

One issue that needs to be addressed is that in many cases, there are no final standards to which a site must be returned to and, every mine and every mine environment is unique.  Increasingly, consultations are occurring between the mine site owner, the community and its stakeholders, and the government concerning what the final site plan should look like.  Ultimate relinquishment of the mine site by a company is impossible unless closure standards are established.

The issue of legal and financial responsibility is at the heart of many rehabilitation projects.  For new projects, legislation may set performance targets in terms of environmental impacts and long-term land-use, perhaps enforced through financial bonds or securities that guarantee the public purse against defaulting companies.  The rehabilitation procedures may already be evaluated at the EIA stage and stipulated as obligations in the project permit.

Many companies now see their relationships with the public as being at least as important as regulatory compliance.  Public acceptance of future mining activity is strongly influenced by its vision of ecological performance at today's sites.  The rehabilitation of sites so as to leave a public asset in the form of farmland, recreation reserves or nature habitat has become an increasingly common policy of mining companies.  Site rehabilitation in these cases goes beyond the mere physical stabilisation of slopes and pits and providing vegetation cover at least cost.

Health and safety has long been regarded as a workplace issue, with objectives being limited to physical safety and protection from exposure to toxics.  While these are still important, additional concerns include public safety from structures during and after operation, the fate of hazardous materials and wastes which may have been buried at the site, and public security of the land after closure.

Beyond the confines of the mine, mining wastes, if not properly contained, can potentially affect public health in both nearby communities and surrounding ecosystems.  Mine wastes may include cyanide compounds, heavy metals, radionuclides and asbestos (though never all in one waste stream).  These can become solubilised or carried as suspended particles in waters leaching from the waste sites.  This leachate, together with drainage from the mine, is often highly acidic or saline, and may also carry a high sediment load.  The common incidents of contamination, which could ultimately affect public health or well-being, include pollution of drinking water supplies, aquatic ecosystems including fishing grounds, agricultural soils and urban areas.

As environmental and safety issues continue to evolve, all aspects of mine management must be reviewed from time to time to see if they are still relevant.  Old practices may no longer be acceptable, as in the use of certain chemicals or in the standards of disposal.  New techniques become available in slope stabilisation, tailings management, in revegetation and in monitoring.  It is necessary for supervisors and managers to remain up-to-date with the latest techniques in order to constantly improve environmental performance.  For this, a constant link with environmental and technical research and development as well as with the changing environmental priorities of governments is an absolute necessity for all managers.

Abandoned Mines - the Legacy of Inappropriate, Insufficient and Non-Existent Mine Closure

One of the major outstanding mining environmental problems is that of abandoned mine sites, a legacy of centuries old practices of inadequate, insufficient or non-existent mine closure.  The potential costs of rehabilitation, the lack of clearly assigned (or assumed) responsibility, the absence of criteria and standards of rehabilitation as well as other factors have delayed action by all parties - industry, governments and communities.  Yet, land degradation from old mine operations is well known in almost all mining countries.

While many have seen these derelict sites - and there are many references in the literature - there have been few systematic surveys to quantify how many sites need attention.  Even less work has been done on trying to quantify the nature of associated problems so as to priorize remediation efforts.

Although a complete inventory is not a necessary prerequisite to start remediating known, serious problems, at some point an inventory becomes valuable in knowing that all abandoned mine site problems have been dealt with.  Towards that end, and to bring attention to this issue, UNEP has begun to compile information associated with the few national or regional inventories that exist although these are mostly in developed countries.  These surveys are still ad-hoc and based largely on internal data collection in some agencies (e.g. abandoned sites on national park lands in the United States).

UNEP and the Chilean Copper Commission co-hosted the first international Abandoned Mines Workshop in Santiago, Chile in June 2001.  Held in conjunction with the Pan-American Workshop on Mine Closure, the Abandoned Mines Workshop looked at problems, issues and challenges for decision makers, the biggest of which is the political will to act, as well as questions relating to who will pay and how the needed monies will be raised.  However, proper and sufficient mine closure is required if the issue and number of abandoned mines is to diminish from now on.

Mine Rehabilitation for Environment and Health Protection - Training

Building capacity to implement new policies in government and industry has been a major activity for UNEP.  The work includes making information available to a wide range of professions, preparing trainers manuals, stimulating the upgrading of training curricula in institutions, and holding training workshops.  In 1998, UNEP produced a training manual on Mine Rehabilitation for Environment and Health Protection.  The manual is designed as an applied, hands-on guide to address the rehabilitation of disturbed land, particularly as it applies to mining lands.  It is a practical, factual method whereby rehabilitation techiniques can be applied.

When the decision has been made to decommission and close a mine, the site rehabilitation plan should be brought to its final stages.  In many countries and for many companies, rehabilitation is an on-going process as part of their operations.  Unless an alternate use has been agreed upon with the nearby community, all physical facilities such as buildings, conveyor belts, silos and chimney stacks should be removed and all logistics features such as roads and power lines should be appropriately rehabilitated.  Also, a closure monitoring plan needs to be established and continued into the next stage, namely the post-closure period.

Post closure is the period following the shut-down and rehabilitation of the mine.  If all environmental impacts have been appropriately and acceptably addressed, there may be a situation where the owner can ``walk away`` from the site.  Monitoring however, will be required over a specific period of time to ensure that all the remedial work is stable, secure and functioning.  However, given that mining companies have little interest in their closed mine sites, there may come a time when this post-closure monitoring becomes the responsibility of a third party, a new type of business, with funding from a type of insurance bond or special fund.

Under some active care conditions, for example, where there are sulfide ores , or in a seismic area, a site may need perpetual maintenance to ensure on-going public and environmental safety.  This would be in addition to the post closure monitoring.  Even under passive care conditions, continual or periodic inspections and monitoring need to take place for some period of time.

Financial Issues

As with all mining operations, there are real and significant financial considerations with respect to mine closure and site rehabilitation, especially given that closure and rehabilitation occur at a time when an operation is no longer financially viable.  This is one major reason why governments are increasingly requiring companies to provide guarantees for mine closure, sometimes referred to as reclamation funds prior to a mine opening.  It is important that these funds be established in accordance with both best accounting practices and in accordance with the tax provisions in the mine's jurisdiction (in some jurisdictions, these funds are required by law).

A range of financial surety instruments exist including cash, irrevocable letters of credit, performance bonds, trust or reclamation funds and insurance policies.  It is important that these funds become auditable items on a company's financial ledgers so as to be publicly reported.  These funds should be established under law and receive monies from the start of a mine's operations.  Company closure plans should be updated regularly in the event that, for economic reasons, a mine needs to be put under "care and maintenance" or in the event of premature closure.  Governments have a role and a responsibility in setting the policy and tax frameworks for these financial instruments.

Social Issues

Although often neglected, the social effects of mine closure are often as adverse as the environmental and economic effects.  In many countries in recent years, mine closures have exceeded new mine openings resulting in a significant number of workers being displaced in countries such as Canada, China, Poland and South Africa.  Some expect this trend to continue over the next decade.  With hundreds of thousands of workers displaced, there is a real need to consider issues such as income, skills training, worker mobility (although many workers do not want to move), physical, and mental well-being and alternative patterns of work.  Mine closures represent a significant social and cultural upheaval as well as having financial implications for a country.

While there are no easy answers to these challenges, many companies are starting to discuss mine closure impacts with the community in advance of mine construction and operation.  This is the case for the copper zinc mine of Cia Minera Antamina (CMA) in Peru.  Antimina, a consortium of Rio Algom, Noranda, Tech and Mitsubishi Corp has discussed with the community elders what they would like to see left in their community after the mine operators remove their equipment and certain mine facilities have been designed and built with community "after-use" in mind.

Institutional and Legal Issues

Current policy and legislative frameworks vary widely around the world.  It is however, increasingly important for countries to formulate clear, stable and predictable policies for industry to follow.  While these policies can and do evolve, they should not fluctuate nor be unequally applied.  It is also important to recognize that each mine is unique, meaning that some flexibility will be required as the mine operates.  Further, artisinal, hardrock and coal mines and aggregate operations are different and need to be treated technically differently although under the same approach.

Future Issues

National environmental policies vary greatly around the world and, it is important to recognize the contribution mining makes to national economies.  Nevertheless, it is clear that while current best practices and regulations in many countries require mine closure plans, one challenge is how to ensure that some companies don't cut corners in an effort to remain competitive.  Further, consideration needs to be given to determining the best way to ensure that small and medium sized companies, of which there are many more, also commit themselves to environmental stewardship and best practices.

There are outstanding financial policy issues that need to be addressed including: how can mine closure and reclamation funds be designated to include artisinal, small and medium sized operations?  How can financial surety options be realistic, flexible and sufficient to address mine rehabilitation yet not so burdensome as to push companies into bankruptcy or deter them from commencing operations?  What are the options to meet the financial burden of reclaiming abandoned mine sites, many from more than one hundred years ago?  How should financial surety instruments be established to ensure they are used for their intended purpose?

The social challenges are also very real.  Just as environmental impact assessments became the tool for measuring a mine's environmental impact, social impact assessments may become the tool to address social impacts.  Perhaps these two mechanisms should be merged into a socio-environmental impact assessment.

Abandoned mines present greater legal, policy and financial challenges than technical ones.  The threat of future liability imposed on third parties that attempt to clean-up sites is a deterrent to progress.  Under the laws of several countries, liability for toxic pollutants is retroactive with no statute of limitations meaning that present owners are responsible for the property in perpetuity even if they were not involved in the original mine.  At the UNEP-Cochilco Abandoned Mines Workshop a range of options were put forward including:

• a small surtax that should be paid by the market into an internationally managed fund;
• consideration of a type of remediation fund for abandoned mine sites;
• encouraging the retreatment of old tailings piles, given the new technology available;
• consideration of "Good Samaritan" proposals for clean up;
• identifying alternative uses for old sites for tourist destinations (e.g. museums), and using associated revenue for site remediation;
• the need to continue to exchanges of views;
• sharing of the costs of rehabilitation by everyone – government, industry, the market (i.e. consumers);
• construction of a consortium like the Mine Environment Neutral Drainage (MEND) programme in Canada; and
• inclusion of abandoned mine sites in any international mining convention or framework agreement.

Conclusions

It is possible that mining in the 21^st century could become a model of an economically viable, environmentally sensitive, socially responsible industrial sector producing sustainable and decentralized benefits to foster other activities and increase capacities in the communities which will endure long after a particular mining operation closes.

In order for this to occur true stakeholder partnerships need to emerge in association with each mining operation.  Industry is challenged to assume greater environmental stewardship and communicate with nearby communities in all aspects of their operations.  As the mining industry is often judged by its weakest member, good companies are urged to persuade those which give the industry a bad name so that they too will improve their environmental and social performance.  National governments need to articulate clear policies and rules for environmental impact assessments including mine closure and site rehabilitation.

UNEP's mission is to provide leadership and encourage partnerships with the private sector and help decision makers in government and local authorities and industry develop and adopt policies and practices that are cleaner and safer, make efficient use of natural resources, incorporate environmental costs and reduce pollution and risks for humans and the environment.  UNEP seeks to stimulate debate on important issues such as mine closure in order to identify new ideas and approaches to the challenges facing the mining industry.

Selected Bibliography

"Abandoned Mine Sites: Problems, Issues and Options", Mining and Sustainable Development II: Challenges and Perspectives; Industry and Environment, Volume 23,  Special Issue 2000, ISSN 0378-9993, pp36-38

"Abandoned Mines: Problems, Issues and Policy Challenges for Decision Makers, Summary Report" UNEP – Chilean Copper Commission, 2001

"Analysis and selection of closure measures for northern Canadian mines", Hockley, Daryl/Schultz, Stephen/Nahir, Michael: Proceedings of the International Conference on Mining and the Environment: Securing the Future, Skelleftea, Sweden, 2001, pp269-279

Berlin II Guidelines for Mining and Sustainable Development, United Nations, 2002

Case Studies Illustrating Environmental Practices in Mining and Metallurgical Processes;  International Council on Metals and the Environment and United Nations Environment Programme,  1996

Case Studies on Tailings Management; International Council on Metals and the Environment and United Nations Environment Programme, 1998

"Closure Concepts", Mining Environmental Management (November 1998)

"Dealing with the Legacy Issue – lessons from 12 years' experience in Ontario: Be Creative; Be Flexible and Be Strict!", John B Gammon, 2002

Environmental Aspects of Selected Non-Ferrous Metals (Cu, Ni, Pb, Zn, Au) Ore Mining: Technical Report Series No. 5; United Nations Environment Programme, International Labour Office, 1991

"Financial Provisions for Mine Closure", Mining Environmental Management (May 1999)

"Major Environmental Issues for the Mineral Sector with Special Reference to Developing Countries", Mining and Environment, Bharat B. Dhar, A.P.H.Publishing Corporation, 2000, ISBN 81-7648-148-3

Mine Closure in Iberoamerica, Roberto C. Villas Bôas, Maria Laura Barreto (Eds.), CYTED/IMAAC/UNIDO, 2000, ISBN 85-7227-132-5

Mine Rehabilitation for Environment and Health Protection: A Training Manual; United Nations Environment Programme, World Health Organization, 1998

"Mine Rehabilitation in Ontario, Canada: Ten Years of Progress", W R Cowan, J G A Robertson

"Total Project Development – A New Approach to Mining", S.Struthers: Proceedings of the International Conference on Mining and the Environment: Securing the Future, Skelleftea, Sweden, 2001, pp814-823