Mining Greece: Environmental restoration in Skouries


The mining activity in the area of the Kassandra Mines began in the Classical era of antiquity and continued until the Roman period. It fell into decline after the conquest of the rich gold and silver mines of Spain by the Romans. The exploitation began again in the Byzantine era, and in the beginning of the Ottoman rule a new period of prosperity started. After some alternating periods of prosperity and decline, the activity began again in the late 19th century. In 1927 the Greek Corporation of Chemical Products &Fertilizers overtook the operation of the mines, at first having as target the production of iron pyrite and, after 1953, when the construction of the enrichment plant in Stratoni took place, the production of concentrates of lead, zinc and iron pyrite.

The current owner, the Hellas Gold corporation states that it is more worth, economically,  complying with the European environmental legislation than paying any fine. Moreover, the European environmental legislation is now very strict. Similar mines can be found in the most advanced countries in the world, such as Canada, Germany, Denmark, Sweden, Finland, which are countries with a very high ecological sensitivity. Those who are opposed raise environmental problems and are not satisfied with the environmental terms of the approved study. Certainly, the condition which is demanded by the Municipality, the involved bodies, the residents of the area and by everyone, is that the mining activity in the area is structured properly, mildly and with strict compliance with, and implementation of the environmental terms, so that there is a substantial prospect, which will consist the continuation of a history of two millennia.

Optimal practices of Hellas Gold 

The cleaning of the surface in the Olympiada area. It is considered as one of the largest projects of environmental restoration of all times. The tailings pond was formed from 1976 to 1995. In an area of 300,000 square meters have been deposited by the Greek Corporation of Chemical Products &Fertilizers 2,500,000 tons of tailings from the operation of the enrichment plant. According to the Environmental Impact Study for the restoration, through removal, of the area of deposit of old tailings in Olympiada, which has been approved in July 2011 along with the general study, the gold-bearing pyrite will be subjected to a special enrichment process, so that its gold content increases from the current 3 gr/ton to 20 gr/ton. The gold-bearing pyrite concentrate which will be produced will be exported to metallurgical plants abroad. In total will be produced by 2016 300,000 tons of gold-bearing pyrite. In this way, Hellas Gold is implementing one of the greatest environmental projects of all times in the area.

Tunnelling between Madem Lakkos-Olympiada. With a construction of a 9km-long tunnel, from Madem Lakkos to the deposit of Olympiada, the pressure on the road network will be relieved, and there will be a proportional decrease of vehicle emissions.

Minimization of the surface area occupation. The exploitation plan of the Skouries deposit has been selected with a view to the minimization of coverage of surface areas. Specifically, a combination of opencast and underground exploitation has been selected and approved by the Ministry of Environment, Energy and Climate Change. The Skouries deposit expands in a cylindrical way from the surface to a depth of approximately 800 meters. The diameter of the deposit is approximately 200 meters. From the three planning options, the corporation selected the one with the minimal coverage of the surface area. It has been approved along with the Environmental Impact Study in the context of the environmental terms of the project which are included in the relevant Joint Ministerial Decision.

Reduction of the acid drainage effect. Each year, measures are taken for the reduction of the acid drainage effect in the area of Stratoni. The measures taken up to now are: the backfilling of the galleries of the old mine in Madem Lakkos and the arrangement of the Giannavos stream, which lies above the mine of Mavres Petres and passes over old exploitations, which were close to the surface. A new measure that it was decided to be implemented in 2012, is the shutting down of gallery 53 of the mine of Madem Lakkos. Gallery 53 is the old mine access gallery.

Environmental measures incorporated in the project plan

As it can be seen in the approved Environmental Impact Study of the project, the new investment plan for the Kassandra Mines has been designed based on the accumulated experience from the long term operation of each mine in combination with the environmental and social background which has been developed in the wider area. The important development of technology offers the capacity of rational exploitation of ores, in combination with the principles and guidelines of sustainable development. In particular, for the development and operation of the aforementioned mines has been selected the approach of implementation of the projects in phases. This approach has been chosen because it facilitates the financial management of the investment, on one hand, and it offers the possibility to adapt the environmental and social impact to actual facts and in accordance with actual evaluated data, on the other hand. The investment plan includes the following basic measures:

1. In the Mavres Petres Mine, the most important problem that has to be addressed has to do with the deposition facilities as these are currently developed, in terms both of capacity and of management. This problem is addressed with the simple unification of these facilities, in combination with the reduction of the enrichment waste moisture, and thus of the deposited volume, with the significant improvement, in parallel, of the qualitative part of the deposition which is now dry and is still protected. This unification regards the already occupied spaces of the left spur of the “Kokkinolaka” stream and expands to the right spur up to a height of 240 m, aiming at the creation of the required single protected facility with a barrier upstream on the national road. It is remarked that the design and construction of the facility must be in accordance with what is provided for in Directive 2006/21/EC9 as it has been incorporated in the Greek legislation by the Joint Ministerial Decision no. 39624/2209/Ε10310, as well as with the Best Available Techniques and must meet the requirements and standards regarding hazardous waste landfills. Furthermore, in the Mavres Petres Mine, along with the production process, takes place the shutting down of the old mines of the area and the restoration of the non-operational, in the new planning, spaces.

2. The full modernisation of the Olympiada Mine is performed through a new large diameter access to the deepest part of the deposit and is completed with the construction of a new enrichment plant in the area of Madem Lakkos, where the mining products are transported through the new tunnel. Furthermore, the unified deposition facility can receive the treated enrichment waste after the reduction of its moisture, since the coarse material returns to the mine as backfilling.

3. The Skouries deposit is fully explored. The exploitation method that must be used is the combination of opencast and underground exploitation. The positive factors of an opencast exploitation are the great retrieval and the non existence of a further exploitation, either in the remaining in situ deposit, or in the “gangue” deposits, without any excessive expansion of the intervention areas due to its implementation. Furtermore, an important advantage of the opencast exploitation is the fact that it has been designed to function as a unified pit and deposition facility (after the cease of operations of the mining activities). The underground method exploits the advantages of a backfilling method which reduces the surface interventions and does not mortgage the expansion of the exploitation to the low concentration ores, with the condition of implementation of a high level of design and of the use of advanced technology.

4. In the Skouries mine, in general, has been followed the limitation of the intervention areas, either in the form of excavations, or in the form of depositions, so that the total area covered by the basic parts of the project does not exceed 1,800,000 square meters. The required deposition facilities, in order to avoid the effect of a cumulative area coverage, are more that two, in such a way that the exhaustion of one of them will mark the beginning of its restoration; these facilities will be placed in the vicinity of the area of the Mine. Furthermore, as in the case of the deposition  facility in Kokkinolakka, the construction of the proposed deposition facilities shall be in accordance with what is provided for in Directive 2006/21/EC, as it has been incoprorated in the Greek legislation by the Joint Ministerial Decision no. 39624/2209/Ε103, as well as with the Best Available Techniques. The plan of the Skouries mine will be completed with the establishment of ore treatment plants which will produce concentrates of Cu and pure Au and which shall be located in the vicinity of the area of the Mine.

5. A basic detail of the plan of the Skouries mine, is the management of water bodies that surround the exploitation area. This management shall be implemented through a properly designed network of wells aiming at, the partial cover of ore treatment needs in water, on one hand, and the return of used water to the same natural recipients, on the other hand.

6. The commercial evaluation of sales of concentrates of Pb, Zn, Cu and of Arsenopyrite with high concentrations of Au and Ag, clearly shows that there is a high added value from the further vertical integration through a metallurgical process, apart from the strategy of production of pure metals, of course, which consists a national goal as well as a directive of the European Union. For these reasons, the establishment of a Metallurgical plant is required. In metallurgy is applied the method of FLASH SMELTING, with the parallel production of sulphuric acid, which regards the treatment of all forms of pyrites with the simultaneous extraction of all the contained precious metals. It is remarked that the proposed treatment method consists one of the mainly proposed Best Available Techniques (BAT) for the treatment of similar deposits, according to the relevant guiding documents of the IPPC directive. Its development has taken place in the Scandinavian Countries (Finland), where it is used in many applications, with the famous sensitivity, in these countries, to the environment, as well as the recognized technical integrity. The method of flash smelting will be applied with the required adjustments for the concentrates produced in the Kassandra Mines. The produced waste requires smaller deposition facilities, while its most important part is fully inert, in the form of slag. It is also remarked that it offers a great energy recovery potential. Therefore, this method is compatible with the technical, social, geographical, morphological and developmental data of the area and is better, from an environmetal point of view, from the technology of Bio-oxidation, Ozonisation and Cyanide Recovery (AVR), that has been selected in the past.

With the adoption of the above measures in the planning of the Project, the protection of many environmental parameters can be guaranteed.

Other environmental measures

Apart from the environmental measures which are provided for in the Environmental Impact Study and are integrated in the initial basic design of the project, there are specific additional measures that regard the minimization of possible effects which can occur in individual areas of the natural environment. The most important of these measures regard a different environmental medium, that is the Climate and bioclimate features, the soil Morphology and visual disturbance, Geology & the Ground, Ecosystems, flora & fauna, the Land uses, the Historical & cultural environment, the Socioeconomic environment, the Aquatic environment, the Atmospheric Enviornment, the Aural Environment & the Vibrations.

Program for the monitoring of environmental parameters

The program for the monitoring of the environment consists a safeguard of a possible review and modification of the proposed measures, in the case that the environmental management targets are not achieved; with its implementation are achieved:

  • The assessment of possible changes in environmental media as a consequence of all phases of the proposed project.
  • The evaluation of accuracy of the effects that have been foreseen in the Environmental Impact Study.
  • The assessment of the degree of achievement of environmental targets, set by the legal terms and thresholds regarding the features and properties of the environmental media.
  • The estimation of the degree of effectiveness and applicability of the corrective measures which are proposed in the Environmental Impact Study.
  • The ensuring of updated data regarding the existing environmental state, within the aforementioned phases of the whole project.
  • The possibility of direct and scientifically documented informing of the competent services, interested bodies and citizens, about the state of the environment in all phases of the project.

The actions of the environment monitoring program have already begun and still continue in the present phase. Some of the actions are:

  • the Ecological Base Study of this study
  • the establishment and operation of weather stations
  • the measurement of quality of surface and underground water
  • the evaluation of the existing conditions of the aural environment
  • the measurements for the evaluation of quality of the atmospheric environment.

All data of the monitoring programme shall be kept in the General Management Offices of Hellas Gold S.A. in Chalkidiki, and shall be available to every competent service, whenever they are requested.

Next are presented the environmental parameters which shall be monitored:

  • Meteorological variables
  • Aquatic environment (quantity and quality of water)
  • Soil and geotectonic characteristics
  • Ecological elements of the natural environment of the Project’s area
  • Atmospheric environment
  • Aural environment

Environmental management system of the proposed project

The corporation (Hellas Gold S.A.) considers that its social responsibilities are an integral part of its activities and a “key” factor for its overall business objectives and that the Environmental Management System consists a useful tool, providing an organised method of recording and control of the environmental performance of the corporation.

The Environmental Management System adopts the tripartite strategy which is used in other quality systems:

  • Control and review of the performance
  • Setting of targets and objectives
  • Implementation of the plan

For the development of a functional and effective environmental management system, are required the recording of individual elements and the identification of activities that must be developed, which are summarized as follows:

Environmental policy: A basic requirement for the development of the Environmental Management System is the satisfaction of the environmental policy principles of the corporation.

Determination of environmental issues and effects: The corporation, in the planning phase of the investment project, shall determine the environmental issues and possible effects.

Handling, storage and use of chemicals: The corporation shall responsibly undertake the management of all issues which are related to the handling, storage, and use of chemicals in the most modern, environmetally friendly and safe way.

Environmental risk assessment: The corporation shall assess the risk of the project’s effects, using globally recognised methodologies. Organisation and environmental liability: The corporation shall define the field of environmental liability of all its executives and employees.

Environmental training and sensitization: Ensuring that all employees and contractors are well aware of their environmental responsibilities and liabilities. Environmental communication (external): The corporation shall examine and respond to the concerns of the local community and of others, regarding environmental protection issues.

Response to emergencies: The corporation shall take into account the possibility of occurrence of emergencies in the context of its activities. Emergency plan: The plan which will be created, shall include a detailed analysis of response to emergencies that can possibly occur in the metallurgical and enrichment plants and in the waste deposition facilities.

Environmental Control – Certification: The corporation shall program and implement a control and certification program, which will include environmental compliance controls conducted by independent certified inspectors, and the verification and attestation of the shut down program by independent bodies.

“Parallel restoration”: An innovative environmental solution 

What does “parallel restoration”mean? The individual projects of which the operability is completed, are immediately restored, in parallel with the progress of the other projects.

In effect, in Stratoni, in a few years from now, the coast and the facilities will be released and given back to the local community for exploitation. In Olympiada, the entire area will be cleaned of all depoistions of the previous exploitations. In Skouries, the restoration will take place in parallel with the progress of the project. In the last day of works, the entire area will be given back to the local community, fully restored and without further delay.

The investment has given priority to the removal, cleaning and restoration of all old intervention areas, from the long-term previous mining activity. The greatest environmental restoration project is already in progress in the area of the location of deposition of old tailings in Olympiada.

The plant nursery of the corporation in Olympiada (Greek Nurseries S.A.) is the plant bank that has been created for the restoration works and at the same time the first concrete example of restoration of a mining area. It is located in the area of the Olympiada Mining Facilities, in the yard of the enrichment plant, at a distance of only 2 km from the village of Olympiada.

It began operating, little by little, in 2007 and today, seven years after, it has reached the point of lying over an area of more than 80,000 square meters, while the plan is that it will exceed 100,000.

At the nursery takes place the preparation of seeds which are gathered from the surrounding area and the development of saplings which are then used in the restorations. The species that are cultivated are mainly forest plants, endemic in the surrounding area and the annual productivity amounts to 1.5 million plants.

In the nursery are working 30 employees, who come from the neighbouring villages, including many foresters. It consists, on its own, an investment for the environment, an investment, the implementation of which has been decided much before the approval of the investment plan for the development of the Kassandra mines and particularly in an area that was previously an old deposition area.

The goal was both to restore this area and to create a plant bank for the restoration of all other areas, and it has been achieved. Finally it must be remarked that for the watering of plants is used water which is drawn by the mine of Olympiada.