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Mining Mirror_Embracing the environmental epoch

Embracing the environmental epoch

Environmental management should be top of mind for mining operations, writes Dr Nicolaas, C. Steenkamp and Leon Lauw.

As more Mines reach the end of their production lives, the practical rehabilitation of the mining sites and long-term environmental challenges need to be addressed. But does the mining industry pay enough attention to environmental issues?

 According to James Lake, partner and principal environmental scientist SRK Consulting, South Africa's evolving environmental regulations have led, over the past 20 years, to a definite move towards appropriate environmental management, as well as a move by the mining industry to comply with regulations - particularly those associated with impact studies. ''The mining industry recognises that they have a legal and moral obligation to undertake mining activities in a responsible manner, and they generally do what is required to obtain legal compliance," says Lake.

 Thus, the appropriate regulations are in place to assist mines in focusing attention on environmental issues and land rehabilitation. However, given the considerable number of mines that the authorities are tasked with overseeing, it is inevitable that the government's capacity would be stretched; the authorities simply do not have the time or the resources to police all operations.  Lake says this has resulted in some mines neglecting their obligations, often at a cost to the environment. To mitigate the constraints to the authorities' capacity, South Africa's legislation contains an element of 'self-policing', where mines are required to assess environmental performance and compliance and then report to the relevant departments.

 ''In the past five years, my observation has been that the more responsible miners are certainly improving their environmental performance; they are moving past the point of merely complying with regulations to actively managing a mine's risk of affecting the environment. In other words, these operators are moving into a space where they are proactively taking measures to mitigate impact -whereas previously, they may only have been reacting after an impact has occurred," says Lake.

 That being said, significant costs are often associated with land rehabilitation. Therefore, in tough economic times, it is not unusual to find mines focusing on production and the 'softer' issues, such as rehabilitation, than having to compete for remaining resources. The lack of resource allocation is the major obstacle to implementing effective rehabilitation strategies.

 According to Lake, mines are realising that if enough resources are not directed towards managing environmental impacts, the mines' operations could fast accumulate a significant  liability that demands to be addressed at closure stage. New legislation currently under development in South  Africa  may assist mines in focusing their resources, to improve the way they manage the liability that will fall due at the end of an operation's lifespan.

Lack of awareness

 Colleen Cluett, director at Cluett Consulting, says one of the biggest challenges is one that also faces society in general: a lack of awareness of the importance of a healthy environment. ''As a society, we are not aware of the true costs of our actions. This ranges from electricity generation to not disposing of our waste correctly (both general and hazardous), and even to the use and disposal of single-use plastics," says Cluett.

 ''As something that is deeply embedded in society in general, it is also something that is embedded in the mining industry," says Cluett. Actions that stem from a lack of environmental awareness include the inappropriate disposal of waste; a lack of stormwater management and subsequent erosion (of topsoil and stockpiles); lack of control of alien and invasive species; and a lack of energy conservation. Also, a lack of awareness of the scope and applicability of environmental law. ''However, we are seeing a tremendous shift away from these actions within the industry. A shift that is also :filtering through to people's lives outside of the workplace, at home, or within their communities," says Cluett.

Legal compliance

 Legal compliance is a big issue and many mining operations, especially junior and small-scale mines, often complain that some environmental laws and regulations are difficult to implement and to comply with.

 Cluett says environmental legislation is extensive, dynamic, and intricate. ''Again, many people are simply not aware of legislation, of how it all fits together, and of what is required in terms of compliance. This is largely because of the amount and complexity of environmental law, but people also appear to be too intmidated or simply too busy to tackle it appropriately. As such, there is also a lot of personal interpretation or just a lack of awareness of the requirements of the law. I think those are the biggest problems," says Cluett. She adds that problem areas include the granting of water use  authorisations and the submission and approval of environmental management plans (EMPs).

 Lake says certain aspects of the legislation are too onerous for the mines. ''The criteria that they impose on  the mines are not necessarily the most appropriate means to mitigate the risks associated with mining activities. Overall, however, I believe we have good legislation that provides appropriate guidance to the industry," says Lake.

 ''The major constraint is a lack of awareness and understanding of the environmental legislation; there's so much that people look at it and switch off. There is also a lack of clarity as to how exactly it is all implemented,"says Cluett. ''But I am hopeful that with time and active participation between industry, supporting industries such as consultants, and government, we can work together to make sure that the legislation achieves its objectives," she adds.

Financing mine closure

Mining companies often fall short of finances when closing a mine and this situation should be prevented. However, with proper planning, it does not have to be a painful experience. ''If mines have invested in a closure planning process - which has included the assessment of the risks that will exist at the time of closure - they should know how they are going to close the mine and what it is going to cost them at any stage of the life cycle. Mines are dynamic by nature, as is the socio-economic environment around them. A closure plan should therefore not be viewed as a 'once-off', but should be revisited on a regular basis to ensure that the closure actions are still relevant," says Lake.

 According to Breton Scott, MD of Bowline Professional Services, all operating mining companies are required to make financial provision in terms of the Mineral and Petroleum Resources Development Act. Mining companies can make financial provision for rehabilitation by means of trusts, financial guarantees through a financial institution, or via insurance policies. Section 37A of the Income Tax Act, 1962 (Act No. 58 of 1962) provides for tax deductions for contributions made to a qualifying rehabilitation trust.

 ''It remains the responsibility of the mining company to regularly re-evaluate their rehabilitation liabilities," says Scott. The Department of Mineral Resources (DMR) insists that mining companies must be able to provide upfront for any shortfall encountered in the provision for rehabilitation liabilities. For companies that only provide for rehabilitation through a trust, it would imply a cash contribution of the entire shortfall amount, which would need to be contributed towards the trust. Commercially, the impact would be that junior mining companies are not in a position to make such contributions, as this would lead to cash flow constraints. ''Many mining companies have opted to provide for rehabilitation expenses through the various insurance products available; a more effective method to manage the cash flow constraints and provide the DMR with the required guarantee(s) for the future rehabilitation liabilities," says Scott.

Practical mine closure

 Rehabilitation of a mine site starts even before the first bucket of topsoil is removed as overburden. Prior to starting with any exploration or mining operation in South Africa, the application requires a detailed environmental study to be conducted by a suitably qualified person. In some instances, financiers are requiring that international best practices, which sometimes extend beyond legal requirements, are adopted when undertaking these studies - an example would be the Equator Principals and Performance Standards. It is now mandatory for an environmental study to include its forecast of the final mine closure commitments, along with the ongoing methodologies necessary to minimise the rehabilitation liabilities.

 The type of mine rehabilitation will depend on the type of mining operation that was conducted. There are significant differences in the rehabilitation philosophies of surface and underground operations. The environmental impact is also a factor of the type of ore mined and the processing method employed. A full description of the methods is beyond the scope of this article and only the key issues are highlighted.

Opencast mines

In opencast strip mining operations, the topsoil needs to be placed on a stockpile, and erosion and loss contained for the entire life of mine. The way in which the mining void is filled is a function of the opencast mining n1ethod used. The spoil material will usually be used to fill the void after the seam has been removed. In the case of quarries or borrow-pits, there will be no spoil material to fill the mined void. As an example, a quarry might be reutilised as a waste landfill site if the environmental approval requirements can be met. With some ingenuity, an old quarry that naturally filled up with water could be used as the central point of a housing estate.

Underground operations

Underground operations generally require less rehabilitation. Shafts are usually sealed with a concrete plug to prevent unauthorised re-entry. Most of the surface infrastructure that can be sold, salvaged by other operations, or recycled, is removed from site. Buildings may be den1olished or repurposed, depending on the mine closure  plan. Long-tern1 monitoring of groundwater, especially in shallow operations located in or that were developed through aquifers, is one of the main rehabilitation and mine closure costs.

 Tailings can remain on surface and be rehabilitated to some extent by planting resilient grasses or shrub species to stabilise the surface of the dump and contain dust pollution. This is a topic that continues to grow with  more research and test projects. In underground operations, tailings may be used as backfill material, reducing the amount of material remaining on surface after mine closure.

 Water monitoring is one of the required aspects of mine rehabilitation that will continue for years after closure of the mine. Water monitoring is done on most, if not all, of the surface water bodies and streams. Monitoring holes are also drilled, especially around old workings and tailings. The type of test work will also be determined by the type of ore that was mined. The tests usually include acidity, alkalinity, water temperature, heavy metals, dissolved gases, and microorganism profiling.

 Access control to potentially dangerous areas would require a permanent security solution. The maintenance of the fencing and security services employed is also a long-term expense. Hazardous materials are not left or buried on site; rather, it is removed to a licenced disposal site.

Mine rehabilitation

Most mine rehabilitation programmes focus on returning the mine lease area to the land capability in which it was before development. This would usually entail restoring, as far as possible, the topsoil to the original condition. This would be followed by the introduction of pioneering indigenous species, such as grasses and weeds, to stabilise the topsoil. The pioneering species will also aid in preparing the soil by re-establishing the soil chemistry, developing the humus layer, and sustaining the establishment of insect and microorganism populations. Depending on the biosphere, shrubs and trees will be planted and their establishment monitored. The appearance of invasive species is also monitored, and the removal of these can be done as a job creation initiative. Strides have been made in the development of'coated seeds' that increase the germination success. In most instances, small wild animals, such as birds, insects, lizards, and rodents, will re-establish themselves, but small and large game would have to be reintroduced.

 Conversely, the mine closure could transition into reutilisation of the lease area for farming activities. These activities are usually planned to be labour intensive to create work for affected persons due to the mine closure. It may take the form of a community project.The type of activity would again be influenced by the type of mining conducted on site. If the ground cannot inmmediately be used, hydroponics or greenhouses  are options. Fish farms are proving to be excellent projects to be run in parallel to hydroponics. Depending on the location, accessibility, safety, and historic significance, mines can also becon1e tourist attractions, much like Gold Reef City or Blaauwbank.

 ''Sites that are deemed too hazardous can be utilised for other industrial or power generation projects. Notable examples could be solar panel farms, biomass and/or recycling pyrolysis projects," says Scott.

Are SA mines ever abandoned?

Scott questions whether South African mines are ever truly abandoned, though. ''Historical operations were mostly stopped due to the operation becoming marginal or due to the grade of the ore body falling below the historical cut-off grade. As mining processing technologies advance over the years, these ore bodies become viable to be brought back into production or to safely mine the remnants, such as underground pillars," says Scott.

 Historical mine dumps have also attracted interest for reworking and reprocessing. In addition, mine dump materials, even though there may be mineral recovery potential, are attractive to supplement the generation of other building materials. Owing to the nature of the smaller mining entrants to the market, historical mineral deposits are being re-evaluated and prospected.


James Lake - Partner / Principal Scientist

SRK Africa