ERAMET strives to protect natural balances sustainable by managing its activities’ environmental impacts and risks. The Group places the greatest importance on characterising and conserving biodiversity and on applying the "mitigation sequence" process. This consists of avoiding, reducing, restoring and offsetting those impacts.
Restoration, which includes revegetation, is carried out progressively on mining sites or at end-of-life on industrial sites. Its aim is to make the site safe, reintegrate it into its landscape, combat erosion and conserve biodiversity.
- SLN, a precursor in the Group
Mine restoration is a constant concern for SLN, the ERAMET subsidiary that extracts and processes nickel ore in New Caledonia. Over the past four decades, it has developed innovative revegetation methods. A real precursor in this field, not only in the Group but for the entire mining community, SLN has contributed to a best practice guide for the industry.
In the 1970s, SLN helped to fund the first three trials conducted by CTFT (technical centre for tropical forests) with forest species on three of its mining sites. On SLN’s initiative in the late 1980s, IRD (research institute for development) undertook further studies that identified around 40 local pioneer species suitable for replanting mining land. Planting of these species began in 1990, with the first hydroseeding in 1994. This new revegetation technique, which is inseparable from planting, consists of spraying seeds (approx. 2,500 per m²) through a pump-fed hose and is useful in hard-to-reach areas. The spray contains mineland scrub seeds that SLN obtains from community nurseries among other sources, mulch (wood fibre and cellulose) and plant substrate. The hydroseeding work is contracted out to a local firm, SIRAS PACIFIQUE, which developed this revegetation technique with SLN.
The revegetation of Tiébaghi’s major stockpile is a practical example of SLN’s experience and its ability to implement a large-scale process that is fully integrated into its operating process in order to guarantee long-term effectiveness. Over its history SLN has developed an advanced process for storing the tailings from its ore processing in stockpiles. The biggest structure of this kind to date (area 300 ha, length 2.5km) is at Tiébaghi in New Caledonia’s Northern Province. Its revegetation was fully integrated into the gradual development and operation process, enabling SLN to combat erosion, integrate the site into the landscape and protect biodiversity. Revegetation is in several stages and continues while the site is in production, which is a significant breakthrough. The teams who helped to develop this practice received an award as part of the Group’s 2013 Initiative Challenge 2013.
To date, it is estimated that the revegetation work begun by SLN in 1993 has covered almost 200 hectares through planting and hydroseeding. This is an outstanding achievement given the types of soil and difficult weather conditions. Moreover, SLN has set itself an annual goal for revegetated surface area in relation to stripped areas.
- Actions gradually implemented on other sites in operation
Their expertise may not be as extensive as SLN’s, but several other Group subsidiaries are working on revegetation in their active units.
Since 2010, COMILOG has revised the mining procedure for Bangombé plateau in Moanda, Gabon, in order to integrate the reshaping and recovery of topsoil. The open-cast mining of this manganese deposit first involves stripping topsoil and removing a layer of tailings, which alters the site’s topography. Around 120ha has been restored in a few years and a fauna and flora study is in progress on the free zones of the plateau where operations are carried out. The aim is to identify a benchmark state and aim for it with natural recolonisation.
Also in Gabon, COMILOG is currently remediating the Moulili River as its bed is laden with manganiferous sediment from the Moanda beneficiation plant. The company is working in partnership with Masuku science and technical university in Franceville (Gabon) to study soil, but also to reproduce and reintroduce endemic plants in order to develop the river’s banks and slopes. Following the work begun in 2010, 170ha will be restored and reintegrated into the valley’s landscape.
Another example is the securing and restoration of a landfill by Aubert & Duval’s metallurgical plant in Les Ancizes, France. Aubert & Duval factored the sensitivity of the neighbouring natural space into its restoration plan in order to protect and rebuild ecological continuity. The first planting phase took place in autumn 2012, with a second planned by the end of 2013. Almost 1,200 trees and shrubs will be planted.
- An integrated approach upstream of project development
Limiting its environmental impact is a major issue for ERAMET. The Group also strives to plan ahead for revegetation and integrate the issue upstream of operations.
This is the case for the nickel deposit mining project on Halmahera Island, Indonesia. To have the inventory needed for reforestation once industrial-scale mining starts, the subsidiary Weda Bay Nickel created nurseries in 2003. These enable it to study plants’ adaptability to different soils, found out their survival rate and carry out research to increase it. Upon completion of the mining tests in 2008, Weda Bay Nickel restored and revegetated a 15 ha zone. 7,000 plants in 19 local species were introduced. 90% of them are estimated to have survived so far. The programme’s effectiveness was borne out in 2013 through a study by local environmental authorities.
In Senegal, Grande Côte Opérations (GCO) is also planning ahead on this issue. The company set up a nursery and began revegetation tests in July 2013 on a 10ha zone.
In Gabon, Maboumine, which is looking into a polymetallic mining project, soon started a nursery creation process that will enable the company to revegetate the site’s deforested parts.