Mining is an increasingly hot topic in the global community. Germany, a country traditionally considered to be a green leader, is just one example of the struggles faced when enacting a rapid and fair coal phase-out. Undoubtedly, the main challenge lies in offering employment solutions to the many miners that will lose their jobs. However, a second question also arises: what will happen to the giant mining areas once they are no longer used for resource extraction? The question is pertinent to all types of mining, from copper in Peru to diamonds in Australia or zinc in Canada.

A mine’s lifecycle goes through different stages. For gold mining, which occurs in open pit mines, the World Gold Council identifies five different phases: exploration, development, operation, decommissioning and post-closure. The decommissioning starts once the ore body has been exhausted or is no longer economically interesting. It includes dismantling and rehabilitating the land. In other words, returning the mine to a state that allows the land to be reused for other purposes including wildlife habitat, recreational areas and industrial land. The last step, post-closure, implies monitoring the decommissioned area over the years, so as to ensure the successful rehabilitation of the land in question.

Usually, the rehabilitation phase, also known as mine reclamation or remediation, aims to return the land to its original environmental state, or as close to it as possible, which includes the safe disposal of hazardous materials and waste, ensuring water quality, and restoring indigenous vegetation. Although reclamation is the last part of a mine’s life, mining companies such as the US-based Newmont Mining Corporation, one of the world’s largest gold producers, say it should be an integral part of initial planning: “Planning for closure begins with the design of the operation, well before construction. Reclamation activities start during production and continue long after mining has ceased, until our closure objectives have been met,” Omar Jabara, Group Executive with Newmont, tells RM. In fact, in most countries mining companies are obliged to establish a rehabilitation plan before the extraction activity begins, or at least set aside funds for this purpose, and many companies initiate progressive rehabilitation processes whilst still mining in other areas. For instance, the German company RWE and Spanish Endesa began converting active mining sites into wildlife and recreational areas while the mine continued to expand in other directions. In the case of As Pontes in Spain, Endesa said that this progressive rehabilitation has been the key to their success.

Therefore, initial planning is an essential factor in converting old mining sites into environmentally friendly areas. However, this is not always possible. On the one hand, thousands of old mines in the world are still abandoned; on the other, unregulated mining activities make it impossible to demand ownership of responsibility. 

Espiel, Spain

Back to the Wild

Returning mining sites to their condition prior to when mining activities began is a very common practice among mining companies. Some of the world’s largest open pit mines have already undergone this kind of transformation. 

In 2011, PT Newmont Minahasa Raya (PTNMR), Newmont’s Indonesian subsidiary, planted hundreds of thousands of trees in an old mining site in southeast Minahasa. The company provided the Indonesian Government with 443 hectares of re-vegetated land. Once a giant hole surrounded by deforestation, Newmont now describes the area as the future site of Indonesia’s new botanical garden, with an already thriving forest of mahogany, teak, nyatoh and sengon trees.

Teck, is one of the world’s leading producers of steelmaking coal, copper, zinc, specialty metals such as germanium, indium and cadmium, and gold and silver. Few markets escape this company. Its broad scope of activities makes ambitious environmental plans even more crucial. In the same line as Newmont, the company says that it works on the rehabilitation of mines throughout their entire operational lifecycle and in cooperation with local communities. Furthermore, they make sure to “achieve a net-positive impact on biodiversity in the areas where we operate. This means that the ecosystem and biodiversity of the mining area and its broader surroundings will be better off than before the mining occurred.” To reach this goal, they use a technique that involves salvaging soil to help in the re-vegetation of degraded areas. For instance, in a section of the Greenhills operation in southeast British Columbia, the company recovered a large area of soil to a depth of nearly one meter and stored it for later use in reclamation activities. During the course of the project, they managed to save around one million cubic meters of earthy material. The stockpiled soil is now being used to cover the areas where mining activity has been completed through progressive reclamation, which will occur from now until 2035.

Freeport-McMoRan, which runs some of the largest mines in the world, including the Grasberg mine in Indonesia, is also undergoing efforts to bring its mining sites back to sustainable use. The company is finalising plans for the construction of tailings recovery test plots for the Cerro Verde copper mine in Peru, one of the ten largest copper mines in the world. The test plots will be studied to confirm the long-term effectiveness of the proposed closure methods, which have been described in the most recent update of the Cerro Verde Closure Plan.

Australia’s largest diamond mine, the Argyle Diamond Mine, owned by Rio Tinto, will soon run out of its rare and precious resource. The mine is both the largest supplier of natural coloured diamonds in the world and one of the largest diamond suppliers in general. The impact that its expected closure in 2020 may have on the world diamond market is a very worrying aspect, and the fate of the mining site itself is of equal importance. Located in the remote East Kimberley region of western Australia, the mine has been operating since 1983: first as an alluvial mine, then as an open pit mine, and finally as an underground mine since 2013. Before mining began, the area was home to indigenous people who have, to some extent, benefited economically from the mine, but have also seen the biodiversity they depend on decrease sharply over the years. Aware of this, Rio Tinto emphasises its intention of “working with local Aboriginal people to rehabilitate areas disturbed by mining in ways that will be directly advantageous to them. Native plant species that are important to their culture, health and diet – and that have been in short supply or in near-extinction in recent times – are being reintroduced to the landscape.” The company claims that the planning for closure and consultation has been ongoing throughout Argyle’s lifecycle. However, the plan remains unclear. Rio Tinto is still preparing decommissioning and rehabilitation proposals that will be presented to Argyle’s traditional owners, Australian aboriginal people, and will be followed by a formal consultation with them before making a decision. The mine closure plan will cover issues such as land use, water management, waste rocks reshaping and biodiversity.

Rough diamonds, Argyle

Europe is also home to many open pit mine rehabilitation projects. In Spain, several coal mines have been converted into “wild” areas or adapted for agricultural and recreational uses. Spain’s largest lake, located in As Pontes, Galicia, with 865 hectares and 547 cubic hectometres of water, was a dirty coal mine only a decade ago. Now, people enjoy the lake as a recreational area, which even has a sandy beach. When RM asked about the potential toxicity of the water, a representative from the owner company Endesa said that the water is so clean that it is even suitable for human consumption. Even more surprisingly, native wildlife is back without having been reintroduced by humans: including 217 plant species and 205 vertebrate animal species identified by Endesa in the area.

As Pontes, Spain

Endesa has also done an impressive job in the old mine of Puertollano in southern Spain, where 560 hectares are now used for agriculture with very high productivity. Here, nearly 30,000 olive trees provide an average of 250,000 kg of olives for oil. In the case of Puertollano, Endesa told RM that the conditions for wildlife are even better than they were before. While the area used to be mostly desert, it has been turned into a Mediterranean forest where wildlife can settle in even greater numbers than before. In both cases, the company began to rehabilitate the areas while the mines were still active. During the process, both the external and internal landfills were given wavy shapes, similar to those of the surrounding environment. After that, they were covered with topsoil and then fertilised and sowed with native vegetation. The final phase involved the recovery of the mining hole, filling it with water.

Time for Fun

Not everything is about wildlife and greenery. Many other mines around the world become event centres, museums and take on a variety of other imaginative uses. 

The Salina Turda mine in Transylvania, Romania, is a giant salt mine that turned into an amusement park. After its closure in 1932, it was used as a bomb shelter during World War II and later as a warehouse for cheese storage. Today, the impressive 122-meter-deep hole hosts an underground playground, where people can go bowling, play mini-golf and ping-pong, or sail across the lake. 

In Dalarna, Sweden, former opera singer Margaret Dells and culture editor Asa Nyman made of an unused limestone quarry an amphitheatre. After the first concert in 1993, artists as famous as Led Zeppelin, Patti Smith and Norah Jones have stepped onto its stage. 

Essen, in Germany, was one of the greyest cities in the country, where everything used to revolve around mining. In 2017, the city was recognised as the European Green Capital for its transformation. Now it attracts a large number of tourists to its former mines, which have been turned into museums and places for other leisure activities, including a giant ice skating rink. A walk through its buildings, designated by UNESCO as a World Heritage Site, is both frightening and fascinating. It invites visitors to get lost and explore, bringing back their childhood curiosity. 

Essen. Photo by Irene Baños Ruiz

Abandoned Holes 

Unfortunately, not all old mines end up being environmentally friendly, beautiful or fun sites. In Australia alone, there are about 50,000 abandoned mines throughout the country. The report Ground Truths: Taking Responsibility for Australia’s Mining Legacies, commissioned by the Australian Conservation Foundation, showed that about 75% of the country’s mines had been closed without proper planning.

The Faro mine is one of them. This lunar landscape, located 15 km north of the Town of Faro, in Yukon Territory, was once the world’s largest open pit lead and zinc mine, but was abandoned for nearly two decades, after its owner went bankrupt in 1998. Its late remediation project is considered one of the most complex ever carried out in the country. The Canadian Government is committed to ensuring a thorough clean-up that considers the needs of the environment and local people. Located across an area of 25 km², mining operations have left behind 70 million tonnes of tailings and 320 million tonnes of rubble, from which heavy metals and acid has begun to flow into land and water bodies such as nearby rivers. Some ponds in the area already show a reddish brown colour. Julia Duchesne, outreach and communications director of the Yukon Conservation Society (YCS), a local environmental group, told RM that “YCS is encouraged that the remediation is finally beginning, after many years of costly inaction.” However, the society also notes that “the effort to clean up the mine over the past 18 years has become a symbol of waste and bungling for frustrated residents in the Yukon. At least $250-million has already been spent maintaining the mining site […] and yet not a handful of dirt has been cleaned up. Instead the government is burning through $40-million annually to run pumps to prevent the tailings from breaching the dams.”

Indeed, Crown-Indigenous Relations and Northern Affairs Canada (CIRNAC), the government department that coordinates the remediation project, told RM that the remediation plan prioritises the stabilisation of pollutants at the site rather than removing them from the area. They will collect and treat polluted water to prevent it from leaking further into the surroundings; place covers across ore, rock and tailings waste; and, of course, monitor the process closely to avoid any unexpected events that could lead to disastrous pollution. It will take another three decades, at least, to ensure that the site is safe for both the local population and the environment.

Environmental groups also raise the criticism that the recovery of mining sites will rarely compensate for the harm caused to the environment. In Germany, for example, there is great controversy surrounding the clearing of the Hambach Forest. The last 1,000 hectares of this ancient forest in western Germany still resist being replaced by the Hambach open-pit mine, Europe’s single largest CO₂ emitter. The energy company RWE says it will take care of the mine once coal is phased out, as it has already done with nearby mines. But activists argue the biodiversity of the forest will simply be lost, especially endemic species such as the Bechstein bat and the middle spotted woodpecker. They use the example of nearby rehabilitated areas as the basis for their argument. Of the more than 32,000 hectares used for lignite mining in the area, almost 23,000 had been reused by 2015. About 12,000 hectares were reused for agricultural purposes, 9,000 hectares were reforested and 800 were filled with water and often became recreational lakes, which are very popular in the summer. This seems like a success, but the picture isn’t complete. According to Friends of the Earth Germany (BUND), information is lacking on the extent of the losses that haven’t been compensated, such as the dry up of rivers and the disappearance of rich wildlife habitats. Moreover, the group says, the reforested areas will never offer the same quality of biodiversity or agricultural purposes as the original soil. 

Another case that has raised criticism is that of the Twilight mine in Arizona, US. More than 900 hectares of brown mining areas look green again, but not even the colour matches with the original heavily-forested mountains, not to mention the enormous loss of biodiversity. It is not an isolated case in the country. Climate Home News conducted in-depth research on the subject to conclude that, in most cases, mine reclamation does not return land to pre-mining levels of wilderness or productivity, and often ends up as low-value grassland. Only 18% of reclaimed land in the US has been converted into farming, housing, industry or recreational areas, whereas 16% was left in a wild state. All the rest was covered mainly with grassland.

Small Scale, Large Damage

Artisanal and small-scale gold mining consist of small actors, mining small areas, rather than large companies. However, although it could be associated with more sustainable practices, there is also a lack of accountability and responsibility. In places like Madre de Dios, in the Peruvian Amazon, thousands of small-scale miners extract gold from the same area, without any of them taking responsibility for the environmental damage. Many of them work illegally, which makes it even harder to establish liability. 

According to the Wake Forest University’s Centre for Amazonian Scientific Innovation (CINCIA), small-scale gold mining has destroyed about 700 km² of primary rainforest in the Peruvian Amazon in the last five years, an area roughly the size of San Francisco. Scientists from CINCIA are working on a very new approach to help the Amazon rainforest recover from the impact of gold mining. Luis Fernández, Executive Director of the CINCIA, lists the different challenges related to their endeavour. Mining in Madre de Dios involves a fairly primitive mining system that doesn’t use heavy machinery and only removes the first five meters of soil sediments. Although it may seem more sustainable than digging galleries and tunnels, it actually leads to the deforestation of a much larger area. Miners get about one gram of gold per tonne of sediment, explains Fernandez. “So, to bring back the forest, you don’t only need to put trees there, you need to generate soil,” he elaborates. 

Credit: CINCIA

The team divided their work into three stages. First, they monitored the state and characteristics of the area with drones and satellite technology. “You can’t assume that all the mining zones are the same, because there are different soil types, different elevations, whether they’re close to a river or in the mountains…” Fernandez explains. Once they identified the testing area, they had to decide which species it would be better to use. Therefore, they’ve planted a series of 50 native tree species in the selected area to figure out what grows best. It is of particular importance in the Amazon due to its high diversity: most of the animals depend on trees and, thus, the species planted in the reforestation project will be determining for the future of all biodiversity. “You don’t want to use Caribbean pine or African Acacia, which grow really fast and are used a lot for reforestation. You’re not trying to restore any old kind of forest, but rainforest.” One of the main challenges remains how to reforest with native Amazonian species in an affordable way. The third stage is the restoration of soil, for which they use so-called biochar, charcoal produced from vegetable matter. It is mostly a reproduction of a method developed by Amazonian native populations about a thousand years ago. The team creates biochar from agricultural waste such as sawdust or the remains of cacao and nut production, and uses it to improve the soil quality in the planting process. “Biochar has very unusual characteristics: it provides carbon for the soil, which is essential, and has the ability to hold nutrients and absorb water. And, potentially, it can even absorb mercury.” Mercury leaks into the soil from the mining activities and may end up in agricultural products. 

The team expects to publish the results of the test plots by mid-2019 at the latest. The conclusions will allow for the first assessment of how we can give back to the Amazon a little bit of the life we have stolen from it. 

The next step is to avoid causing damage in the first place.

Ground Truths: Taking Responsibility for Australia’s Mining Legacies, www.mpi.org.au/2016/06/grond-truth-taking-responsibility-for-australias-mining-legacies

Top image: Faro Mine. Credit: Government of Canada