S3: Borralha (Montalegre, PT)

Site “S-3”, Location: Borralha Mine, Salto, Montalegre, Vila Real District, Portugal 41º 39’ 25.18’’ N 7º59’ 05.19’’ W

Brief description:

The Borralha mine started its operations in 1902 in the parish of Salto, municipality of Montalegre, covering a total area of about 2 611 hectares. The mining focused primarily on the wolframite and scheelite ores. In 1986 the mine closed, leaving large quantities of waste from the treatment of the ores, such as large volume heaps and the tailings dam of the washing plant, without containment measures. This accumulation of waste is widespread throughout the mine area, being a source of contamination of the soil and surrounding environment and producing the drainage of acidic waters.

In the framework of the PhytoSUDOE project (SOE1/P5/E0189) that ran for 3 years, experimental fields with sunflower (Helianthus annuus) and poplar (Populus sp.) were established in a contaminated area belonging to this mining zone, combining different agronomic cultivation techniques and bioinoculum. In this new Phy2SUDOE project (SOE4/P5/E1021) the poplar fields (perennial crop) previously established will be monitored, which will allow to evaluate the success of the implementation of the phytotechnologies in the long term.