PROJECT DESCRIPTION
BACKGROUND
Mining has a high economic importance for fundamental strategic sectors of the EU. However, in several cases runoff and sediments from mines affect downstream water quality, wildlife in rivers and hydro-morphologic properties. The generation of solid and liquid wastes such as acid mine drainage (AMD), and their release on land and into waterways, represent critical pressures of mining on the environment.
OBJECTIVES
LIFE RIBERMINE worked in two derelict mining exploitations in Spain and Portugal to demonstrate solutions respectively aimed at minimising hydro-morphologic pressures caused by non-metal mining on freshwater bodies and at improving the water quality of an area affected by AMD, both in line with the objectives of the Water Framework Directive (2000/60/EC).
Specifically, the project aimed to:
- reduce hydro-morphological pressures in the Tagus River (Spain) and chemical pollution in the Corona river basin (Portugal) by improving in one case the dynamics of the river and in the other case the quality of the water after restoration of two severely degraded areas;
- apply and adapt a combination of the Best Available Techniques (BAT) for mine restoration, based on fluvial-geomorphic solutions, used so far only at a pilot scale, on larger areas (demonstration project) and transfer these techniques to other mine-degraded areas in the EU.
RESULTS
Despite suffering some issues and delays, the project results have been overall very satisfactory. In total, 27.4 ha have been restored in Alto Tajo (Spain), of which 14 ha benefitted from landscape remodeling treatments (including the plantation of 3,522 individuals from 20 species) and 1.78 ha at the pilot site of Lousal (Portugal).
At the Spanish site, the main objective of removing the physical pollution from the abandoned mines of Peñalén affecting the Tajo fluvial system was accomplished. The soil erosion was reduced from 353 t/ha of sediments per year to 3-7 t/ha per year. This resulted in the removal of the alteration caused by sediments on the Tagus River directly over 3.3 Km of the River Basin District of ‘River Tajo from Peralejos of las Truchas to River Gallo’ (ES030MSPF0114010). Effects on the aquatic habitats are expected to take place in the future as the ecosystem adapts and will be further monitored in the After-LIFE. With sediments representing also one of the pressures affecting the SPA and SCI/SAC Alto Tajo (ES4240016-ES0000092), the project has also contributed to the integrity of the Natura 2000 network. The possible evolution of the vegetation cover recreated in the area of Santa Engracia towards species and habitats of EU importance offers also an opportunity in the long run to extend the area under protection.
In Lousal, the restored surfaces have behaved adequately, showing a high stability without having undergone any geomorphological change. In addition, a high herbaceous vegetation cover of almost 100% has been achieved. The project restoration has brought to the reduction of groundwater pollution levels, increasing the pH to a range close to neutrality (6.3 – 7.0). However, the evolution of this parameter in surface waters during the project implementation was limited. This was due on the one hand to the small area of the pilot site in relation to other non-restored areas; on the other hand, external pressures affected negatively neighbouring sections of the Corona River. This has produced a weaker effect of the restoration activities implemented at this site on the quality of the surface waters. Further monitoring of the water quality will continue in the After-LIFE. Discussions have started during project implementation with the entity responsible for the external pressure to solve this problem in the future.
The LIFE RIBERMINE project is the most complete and diverse geomorphic restoration project of a mine in Europe and worldwide, considering that:
- it is the largest Fluvial Geomorphic Restoration (GeoFluv – Natural Regrade) site built in Europe;
- it featured the first application of the Talus Royal method to a mine site in the world;
- it featured first instance in the world of combining geomorphic restoration for unconsolidated materials (GeoFluv – Natural Regrade) and hard-rocks (Talus Royal) (Peñalén);
- it featured the first example in Europe of combining geomorphic restoration with chemical remediation for a mine site (Lousal);
- it is the first to use Landscape Evolution Modelling (SIBERIA) for mine restoration in Europe.
The project solutions have been replicated in 74.5 ha of mines already restored, being projected the implementation in 193.5 ha more (181 ha of them in Sweden and Colombia). In addition, the project implementation has attracted investments for EUR 1.7 million for complementary activities, executed by other administrations.
Reference to the LIFE RIBERMINE project is also included in the ‘Order 138/2022, of July 7, of the Ministry of Sustainable Development’, which establishes the minimum content of certain documents of the extractive industry of Castilla-La Mancha.
The beneficiaries have also been very active in dissemination and capacity building components of the project. They organised six training courses for 11 mining organisations and published 3 scientific papers, 1 PhD dissertation, 8 master’s thesis, 2 end-of-course papers, 9 dissemination articles and deserved its appearance, as an example, in the well-acclaimed book 102 THINGS TO DO WITH A HOLE IN THE GROUND. Furthermore, they participated in 9 international and 6 national conferences and organised 7 conferences and seminars. Finally, the project was awarded a best practice award (EU Green Deal) and a dissemination award and it received the Castile-La Mancha Environment Award, in the Environmental Quality category. These outstanding achievements and decorations highlight that the project has been considered one of the most complete mine restoration projects at the European level, with potential application at global level.
