The largest heap (E6) is located to the east of the cut and has a volume of approximately 550,000 m³ of sterile material. The remaining heaps total a volume of approximately 30,000 m³ of material. The surface of the heaps in question exhibit low to medium radiometric values, and are classifiable in the classes of materials resulting directly from extraction operations, without any type of processing or treatment via leaching.

The intervention to be carried out in this mining area will consist of the following activities:

• Site clearing and deforestation;
• Stabilization of unstable slopes of the cut;
• Concentration of materials in the main heap;
• Slope shaping, with the creation of platforms;
• Maintenance of the water surface;
• Confinement and multi-layer sealing;
• Drainage systems;
• Pedestrian paths in the area surrounding the cut and the main heap;
• Improvement of primary access;
• Permanent outer fencing and access gates;
• Landscaping, monitoring and control of local environmental conditions.

The investment is co-financed by the Cohesion Fund and will enable the environmental liabilities resulting from mining to be resolved in this area, bringing benefits to the local population by improving current conditions and enabling the use of the reclaimed areas for other purposes.

The environmental remediation work of this mining area included the aspects of safety and the environment.

In terms of safety, the interventions consisted of sealing all existing underground mine infrastructure, ensuring the protection of mining galleries, as well as the sanitation, protection and sealing of some open excavations, reducing the risk of people and animals falling into them and controlling their entry into these infrastructures.

Regarding the environment, the proposed interventions focused on the cleaning of the external part of the former “fines” dam of the washery to contain the dispersion noted, landscaping and action to contain some scattered heaps next to former mining works, and in the industrial area.

This contract was awarded to MT3 – Engenharia e Obras, Lda for € 500,594.50 and lasted for 145 days.

The investment was co-financed by the Northern Regional Operational Programme under the III Community Support Framework and made it possible to minimize the safety risks related to the galleries, excavations and cuts, which were unprotected, improve the safety at the fines dam and mitigate the impacts on the appearance and landscape of the area.

The environmental remediation contract of the former mining area of Valdante, included in that of Cunha Baixa, consisted of the following main activities:

• Clearing of the intervention area;
• Adjustment of access to the mining area and dump area;
• Execution of a provisional drainage system;
• Routing to the nearest water line of the water contained in the former open pit;
• Partial demolition of the existing fencing (only to the length required for execution of the earthmoving works under safe conditions of transit);
• Spreading and compacting of the materials from the spoil heap and soils originating from the drainage measures in accordance with their radiometric readings;
• Final forming of the slopes to increase stability and make adjustments to the local morphology;
• Execution of the dump cover system;
• Construction of the permanent drainage system;
• Fencing off of the dump;
• Landscaping of affected areas, including the improvement of paths, the replacement of pit fencing, the implementation of a seeding and plantations plan with the use of native species and the substantiation of the signage plan.

This contract was awarded to Empreigalde – Engenharia e Construção, SA for € 3,749,095.91 (including Cunha Baixa) and had a duration of 540 days.

The investment was co-financed by the Cohesion Fund and allowed the environmental liabilities resulting from mining at this location to be resolved, bringing benefits to local populations through the improvement of current conditions and use of the areas reclaimed for other ends.

The environmental remediation contract of Pedreiros, included in that of Bica, Carrasca, Coitos and Vale d’Arca, consisted of the following main activities:

• Removal of existing spoil heap materials and their controlled disposal at Bica dump;
• Landscaping.

This contract was awarded to Socopul – Sociedade de Construções e Obras SA / MT3 – Engenharia e Obras, Lda for € 2,194,775.53 and had a duration of 540 days.

The investment made was co-financed by the Cohesion Fund and enabled sources of contamination of the soil to be eliminated through the removal of contaminated residues, greatly improving the landscape of the valley, with a consequent increase in the quality of life of adjacent populations.

The environmental remediation contract of Coitos, included in that of Bica, Carrasca, Pedreiros and Vale d’Arca, consisted of the following main activities:

• Concentration and sealing of sources of pollution in chemical and radiological terms, reducing the presence and dispersion of the contaminants;
• Ensuring the safety and improving the quality of life of the population;
• Forming of the land and drainage of the spoil heaps or their treatment with suitable soils, providing a reduction in the risk of contamination and allowing the development of vegetation;
• Promoting the repopulation of native flora and fauna;
• Restoration of watercourses previously affected and the restoration of the quality of the water that drains into those watercourses;
• Cleaning and treatment of contaminated areas, enabling the use of the soil under suitable conditions;
• Creating of separators and elements to deter contact with areas of risk in terms the endangerment of people and animals (shafts and/or the mine entrance and other points of contact with the galleries).

This contract was awarded to Socopul – Sociedade de Construções e Obras SA / MT3 – Engenharia e Obras, Lda for € 2,194,775.53 and had a duration of 540 days.

The investment was co-financed by the Cohesion Fund and enabled sources of contamination of the soil to be eliminated through the removal of contaminated residues and the sealing of the mining structures, greatly improving the landscape of the valley, with a consequent increase in the quality of life of adjacent populations.

The environmental remediation contract of Carrasca, included in that of Bica, Pedreiros, Coitos and Vale d’Arca, consisted of the following main activities:

• In the southern area, the cleaning of remaining materials with still high radiometry readings, forming and adjustment of the slope and its landscaping;
• In the northern area, the removal of material with higher radiometry readings and in situ treatment of the remaining spoil heap;
• Partial removal of spoil heap A, accompanied by a smoothing of the slope;
• Manual drainage of agricultural land located west of spoil heap A and subsequent covering with arable land;
• Cleaning and sealing of the existing gallery entrances in the northern area, effected by means of a metal grating allowing the entry of bats and preventing the entry of people;
• Improvement of the spring area to facilitate oxygenation of the water and thus promote iron precipitation, ensuring its use for purposes of irrigation.

This contract was awarded to Socopul – Sociedade de Construções e Obras SA / MT3 – Engenharia e Obras, Lda for € 2,194,775.53 and had a duration of 540 days.

The investment was co-financed by the Cohesion Fund and enabled sources of contamination of the soil to be eliminated through the removal of contaminated residues and the sealing of the mining structures, greatly improving the landscape of the valley, with a consequent increase in the quality of life of adjacent populations.

This was the 1st Environmental Recovery Work in Portugal, the interventions having focused on the spoil heap and the mine bottom effluent.

Under the contract for the environmental recovery of the spoil heap, the main activities were:

• Sealing of the Master Shaft;
• Re-profiling or forming of the configuration of the spoil heaps;
• Sealing and waterproofing of the re-profiled dumps;
• Reorientation of the natural drainage of the surrounding areas, by means of the implementation of a peripheral surface drainage system;
• Implementation of a surface and subsurface drainage system;
• Implementation of an underground drainage system;
• Landscaping of the site;
• Installation of fencing and proper signage;
• Demolition and cleaning of the ruined former facilities.

In 2006, a second contract for the installation of a mine effluent treatment plant was performed.

The first contract was awarded to the consortium Jeremias de Macedo & Cia / MT3 – Engenharia e Obras, Lda for € 5,361,538.02 and had a duration of 240 days. The second was awarded to MT3 – Engenharia e Obras, Lda for € 356,795.51 and had a duration of 90 days.

The investment made was co-financed by the Environment Operational Programme under the Third Community Support Framework and enabled the creation of general conditions of safety, given the proximity of this mining area to a residential area, and the attenuation or reversal of environmental damage and also the mitigation of impacts of a visual and landscape-related nature.

The environmental remediation of this was carried out under two contracts, both in 2007, which consisted of the following main activities:

• Forming of the silt spoil heaps;
• Sealing and packing of the shafts;
• Demolition of washing station and other buildings;
• Seeding;
• Recovery of the winch;
• Conservation of heritage;
• Landscaping.

These two contracts were awarded to MT3 – Engenharia e Obras, Lda and Jeremias de Macedo & Cia, Lda  for a total amount of €  338,181.12 and had a total duration of 210 days.

The investment made was co-financed by the Northern Regional Operational Programme under the Third Community Support Framework and allowed the space circumscribed by the former mining area to be made safe for use, reducing its environmental impact and creating a pleasant space for leisure, with the best that nature has to offer.

The environmental remediation work at the Murçós mining area consisted of the following main activities:

• Tailings Dam
  • Protection of the mouth of the drainage well;
  • Cleaning/drainage of sludge and scattered debris;
  • Forming/containment of sludge.
• Pits 1, 2 and 3
  • Cleaning of debris adjacent to the pit;
  • Adjustment of embankments with safety steps and proper inclination;
  • Maintenance of the respective lakes and recreation of conditions for the development of macrophytes (Typha and Juncus).
• Pit 4
  • Filling of slopes with spoil heaps;
  • Moulding of slopes;
  • Protective fencing.
• Heritage
  • Demolition of structures and buildings in ruins for pit no 4.
• Revegetation

This contract was awarded to MT3 – Engenharia e Obras, Lda for € 374,151.55 and had a duration of 180 days.

The investment made was co-financed by the Northern Regional Operational Programme under the Third Community Support Framework and enabled the creation of full conditions to allow people to safely use the space circumscribed by the mining area, almost completely reducing its environmental impact and creating a pleasant space for leisure duly integrated into the local environment.

The environmental remediation work at Montesinho mine consisted of a first phase followed by a complementary phase, in which the main activities were:

• Outer fencing off of the mining area (> = 50 ha) to prevent intrusion;
• Detailed inventorying on the surface of the shafts/chimneys/galleries and subsidence/landslides;
• Protection/sealing of wells, galleries and chimneys;
• Smoothing of slopes;
• Forming of slopes;
• Revegetation.

The main and complementary contract were awarded, respectively, to the consortium Tecnovia – Sociedade de Empreitadas, SA / LTO – Lavouras e Terraplenagens do Oeste, Lda and to Construções António Joaquim Maurício, SA, for a grand total of € 1,539,204.44 and a total duration of 230 days.

The investment made was co-financed by the Northern Regional Operational Programme under the Third Community Support Framework and enabled the restoration of minimum conditions of safety for the area, turning it into a space people could use without fear of falling into the mine shafts and chimneys located in the middle of the heap.

This environmental remediation work consisted of the forming, sealing and packing of shafts and galleries, the construction of drains, treatment of sewage from the mine and revegetation, as reflected by:

• Modification of the forming in order to reduce the sealing and containment area of the silt dam;
• Sealing and packing of shafts and galleries;
• Construction of surface and floor drains;
• Construction of enclosures in industrial buildings;
• Treatment of mine drainage water;
• Revegetation.

This contract was awarded to the consortium Ricobra Construções, Lda / Sousa Resende & Robrigues II Construções e Obras Públicas, SA for € 198,350.11 and had a duration of 180 days.

The investment made was co-financed by the Northern Regional Operational Programme under the Third Community Support Framework and enabled the creation of general conditions of safety, given the proximity of this mining area to a residential area, and the attenuation or reversal of environmental damage and also the mitigation of impacts of a visual and landscape-related nature.

The environmental remediation works of the former mining area of Covas consisted of the following main activities:

• Forming and Waterproofing of Spoil Heaps
  • Drainage and recovery of the spoil heap of Foundation E1. Cleaning for E2, 3, 4, 5;
  • Forming and waterproofing/consolidation of spoil heap E2, 3, 4, 5 in areas with gullies, with slopes suited to the stabilization of safety and the desired visual impact;
  • Reinforcement with protective walls.
• Drainage/Treatment of Surface Water
  • Reopening and reformulation of perimeter clean water and rainwater ditches;
  • Construction of internal leachate drainage systems;
  • Conduction of drainage of leachates to “Ribeira Wetlands”, in the Ponte Brasil and Poço do Negro streams, tributaries of the Coura river.
• Heritage
  • Demolition of surface infrastructure without heritage value and in ruins for E2, 3, 4, 5.
• Safety
  • Safety fence (possible);
  • Protection/Sealing of galleries.
• Renaturation and landscape recovery
  • Land revitalization of the coverage of the spoil heaps;
  • Reforestation/replanting of affected areas, aimed at the renaturation and landscaping of the area.

This contract was awarded to MT3 – Engenharia e Obras, Lda for € 567,643.20 and had a duration of 270 days.

The investment was co-financed by the Northern Regional Operational Programme under the Third Community Support Framework and allowed minimization of the highly negative impact resulting from air and water pollution associated with the large volume of debris in the area, as well as the creation of conditions and encouragement of the economic activity of the land, ensuring for this purpose a new environmental framework, the development of vegetation, restoration of natural wildlife habitats and improvements to the landscape of the site.