The environmental remediation work on the former mining area of Cunha Baixa, which included Valdante, consisted of the following main activities:
- Preventing the water transfer that existed between open pit I and the underground part of the mine, promoting a decrease in the flow of contaminated influent from open pit I;
- Eliminating the potential for reactivity, significantly reducing radiometric levels and controlling the geochemical and hydrochemical dispersion associated with existing deposits, whether more enriched spoil heap materials or former treatment sludge;
- Decreasing the emission and consequent dispersion of radon gas into the atmosphere;
- Optimizing the structures and processes associated with the control and treatment of acid effluents;
- Guaranteeing the stability of the slopes of the bulkier spoil heap (E1);
- Controlling surface runoff around the entire perimeter of the mining area, in order to decrease phenomena of gullies and uncontrolled flows of rainwater into the area of the 4 existing open pits (I, II, III and IV);
- Improving the general safety conditions for people and animals;
- Integrating the landscape and ecology of the entire area directly affected by the mining activities, as well as the areas in the immediate vicinity;
- Treating the contaminated areas with agricultural land and;
- Promoting the downstream irrigation of areas for agricultural use with proper quality water.
This contract was awarded to Empreigalde – Engenharia e Construção, SA for € 4,611,523.66 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.