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Harmony Gold’s novel approach to mining land rehabilitation

Harmony Gold’s novel approach to mining land rehabilitation

Sep 1, 2014

By Robbie Louw, director , Promethium Carbon

Mining has always had a substantial impact on the environment and South Africa has always been one of the most affected countries.

Prior to the enactment of the 1991 Minerals Act, mining companies took either a reactive approach to land rehabilitation and complied with minimum requirements, or only superficially rehabilitated mining affected land, post mine closure. This has left South Africa with a huge economic and environmental burden, not to mention the long-term residual risks to communities residing in the vicinity of un-rehabilitated mining areas.

Progress has been made regarding mining land rehabilitation since the early 1990s with the enactment of the 1991 Minerals Act – an Act which enforces environmental protection and therehabilitation of land that has been affected by mining or prospecting activities.

Other legislation, such as the 1998 National Environmental Management Act, the 1998 National Water Act, the 1965 Atmospheric Pollution Prevention Act and the 2002 Mineral and Petroleum Resource Development Act (MPRDA) have provided further controlling measures. Now, the South African government has adopted the “polluter pays” principle, where mining companies need to pay to remediate the damage caused. Concurrent mine rehabilitation is considered throughout the entire life of a mine, from the start of prospecting to the mine closure.

While this legislation has come at great benefit – through the protection of groundwater and ecosystems – it has also imposed stringent requirements for post-mining land usage. Land that has been subject to mining activities can often not be used in the short term for one of its most important functions, agriculture.

Mining-affected land is known to have low soil fertility and is often contaminated by acid mine drainage. This means that mining companies are typically restricted to rehabilitating their land to grasslands or vegetated landscapes with little beneficial use. Interesting though, a changing climate is becoming one of the factors that is prompting mining companies to think differently about post-mining land use.

Harmony Gold is one such company that is taking a novel approach to mining land rehabilitation. In the past, complying with the MPRDA was always effective in meeting the company’s rehabilitation objectives. However, Harmony realises that this is no longer enough.

Graham Briggs, Harmony’s chief executive officer, explains: “As a large mining company, we have always been aware of the need to follow good environmental practices and reduce the long-term negative impacts from our mining land. We also operate our business cognisant of climate change. What differentiates us is that we are continuously identifying land that we can rehabilitate to a sustainable, value-creating alternative use that also mitigates climate change.”

To this end, Harmony has developed a long-term land rehabilitation strategy composed of two elements. The first is to create carbon sinks on mining-affected land. Harmony has around 65,000 hectares of land under management, and recognises that if the restoration of former mined land is done properly, it can potentially capture large quantities of atmospheric carbon dioxide.

Instead of following standard rehabilitation practices, such as grassing, Harmony plants species such as Sweet Sorghum, Sugar Beet and Giant King Grass – plants known for their high carbon sequestration potential.

“By increasing the carbon stock on our land, we can help address the global climate crisis by slowing the growth of carbon emissions into the atmosphere. In the future, we may also use our sequestration projects to generate carbon credits, which can potentially beused as offsets against South Africa’s proposed carbon tax,” Briggs says.

Interestingly, in mining areas known for high radiation levels (such as the Joint Metallurgical Services site in the Free State), Harmony is following a similar approach as undertaken in Chernobyl. These areas will be vegetated with phyto-remedial plants to absorb radiation, which will also help to reduce underground contamination and restore the soil balance.

The second element of Harmony’s rehabilitation strategy is to plant energy crops on mine impacted land with zero economic value and to transform the land into a self-sustaining, renewable energy generation system with commercial value. Once harvested, these crops will be converted into a renewable energy, in the form of biogas, through an anaerobic digestion process.

This biogas will be used to replace fossil fuels in Harmony’s metallurgical plants. The implementation of the first phase of this bio-energy project is planned to start in September 2014. This phase will have a capacity to replace 71,000GJ of fossil fuel at Harmony’s 1 metallurgical plant, and will secure 11 permanent jobs. The success of the first phase will trigger the larger 185,000GJ energy generation plant, which has the opportunity to create approximately 400 direct and indirect job opportunities.

Although South African legislation already requires mining land to be left in an improved state, the companies that are taking an innovative approach to land rehabilitation will ensure that their legacy continues.

Briggs says: “Companies that demonstrate responsibility and leadership in respect of mining land are those who are committed to their own sustainability. As energy becomes an increasingly expensive resource and carbon emissions become constrained, we recognise that new thinking is required to tackle these problems. By changing the way we rehabilitate our mining land, we are able to create economic, social and ecological benefits for our mining communities in the years to come.”

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