On 26 May 2017, EDM – Empresa de Desenvolvimento Mineiro, SA, assigned the works contract to Conduril Engenharia, SA, which is the start of the first phase of the environmental reclamation works in the São Domingos former mining area in the municipality of Mértola, with a value of 2.8 million euros.

POSEUR will fund 85% of eligible costs.

This work has a deadline of 14 months and should be concluded by 31/8/2018.

The contracted work will involve the construction of a retention basin and an irrigation system on the right bank to divert the water from leaching pollution, thus significantly reducing the amount of acidic water. The intervention will also enable a reduction in the discharge of pollutants, particularly in the Rio Chança dam.

In addition, the intervention of this 1st phase as a whole includes the following actions:

• Quality monitoring of surface water and groundwater;
• Surveys for collecting soil samples, waste and contaminated materials;
• Analysis and laboratory testing of the geochemical characterization of the soil samples, waste tips and contaminated materials;
• Hydrological and piezometric control with collection of samples;
• Installation of a weather station;
• Topographical surveys;
• Updating of the master plan;
• Study of the modelling of acid water and hydrochemical contamination;
• Geotechnical analysis of soil and waste;
• Specialised technical inspections for construction, environment, security and archaeology.

The total investment of this 1st phase is approximately 3.8 million euros.

The intervention of EDM – Empresa de Desenvolvimento Mineiro takes place under the concession contract awarded by the State, on an exclusive basis, for the environmental reclamation of degraded mining areas (DL 198-A/2001-6/7).

After this 1st phase there will be 5 more phases.

The mining area of São Domingos, decommissioned in 1966, was mined for copper and sulphur for the production of sulphuric acid, as well as by-products such as lead, nickel, cobalt, silver, cadmium, arsenic, antimony and tin.