Environmental Remediation in the Bica Mining Area

Location

Sabugal (Municipality)

Investment

2,699,573.90 €

2011 - 2013

Environmental Remediation in the Bica Mining Area

Concluded

The former mining area of Bica is located near the town of Quarta-Feira, civil parish of Sortelha, municipality of Sabugal and district of Guarda.

Underground mining operations took place from 1951 to 1961 (phase of the CPR), with two master shafts and cross-cutting galleries measuring 300 m having been opened along the lode and up to the 7th floor, with excavation continuing until 1977. From 1977 (the JEN/ENU phase), shaft 1 was sunk to the 8th floor (a depth of 250 m) with excavation of the 8th floor of preparation of the mine for leaching the former excavations. The in situ leaching of the excavations from the surface was processed with the injection of acidic solutions through holes and chimneys connected to the galleries on the lower floors and the collection of liquors on the 8th floor. In the final phase, the mine was allowed to flood, with the liquors being pumped from the 5th and 6th floors. The production of this mine is estimated at around 132,000 tons of ore with an average U₃O₈ content of 0.20%, which produced 265,900 kg of U₃O₈. With effect from 1977, static leaching was implemented on floors, of poor ore from Bica and nearby mines (Pedreiros and Carrasca). In 1988, it began receiving acid leachates from the Barracão Factory and the unprocessed rich minerals contained therein.

The contract for the environmental remediation of the former mining area of Bica, which included the adjacent mining areas of Val d’Arca, Pedreiros, Carrasca and Coitos, 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;
Modelling 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;
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 allowed the proper treatment of mine waters that flow from the gallery of Master Shaft no 2, thereby reducing the radiometric levels and preventing the seepage of surface water into the spoil heap materials and subsequent hydraulic dispersion of contamination to adjacent areas.