Environmental Remediation of the Valdante Mining Area

Location

Mangualde (Municipality)

Investment

4,866,747.48 €

2011 - 2013

Environmental Remediation of the Valdante Mining Area

Concluded

This former mining area is located 0.8 km from the village of Mesquitela and 1 Km from Cunha Baixa, at the foot of a moderately steep slope facing north and at average elevations of 400 metres. It is a relatively isolated region in terms of habitation, being situated in a pine forest with dense bush and difficult to access. In the vicinity and downstream of the area there was, in relatively recent times, intensive agriculture, which is now abandoned.

The Valdante mine is of the radioactive group. This mine operated as an open pit from 1986 to 1987, but did not reach the levels of development originally planned due to the depletion of mining reserves. Only around 1,050 kg of were produced contained in ores with a U₃O₈ content of 0.089%. There was no kind of leaching at this mine. The poor ore was partially transported to the pits of Cunha Baixa mine, where it was leached.

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.