Mining in Brazil is concentrated in regions with high water demand such as the Southeast. The mineral industry plays an important economic role in Brazil and in certain states such as Minas Gerais, it represents approximately 55% of the gross domestic product. The multiple interfaces between mining and hydrographic basins, with urban and protected areas, make the environmental management of water resources aimed at mining increasingly complex.
Unlike other countries, such as Chile and Peru, where mining is carried out in regions with low population density and little water availability, in Brazil the most extensive mining activities are precisely concentrated in regions where water demand is greater and where, as already
mentioned, there is a high urban concentration. Added to this problem is the fact that mining, which currently uses increasingly complex and lower grade ores, needs to expand scale, reduce costs and reduce logistics. The punctual intervention starts to have, therefore, a “dimension
territorial” (Ciminelli 2010).
The mining activity has a close relationship with the quantity and quality of water, as water is the main input for the industry, whether in the treatment of ores or in the production of residues that impact surface and underground water. Water is, therefore, an extremely important conductor for the search for innovations that promote better management and control of mining areas, better training of researchers, managers and technicians with high technology and systemic vision, and basic scientific advances for application to sustainable regional growth.
One of the problems that must be considered in the advanced view of environmental management of water resources for mining is the determination of the impact of mining not only punctually, but beyond the physical boundaries of the enterprise. There are contaminants from other sources and origins, such as untreated sewage waste from urban areas and non-point sources from agricultural and industrial areas of various types.
There is a strong need to expand the database to assess water quality and further understand the physical and chemical factors that lead to the bioavailability of metals. The assessment of bioindicators should come from regional biodiversity studies comparing pristine areas with areas impacted by mining (Ciminelli & Barbosa 2008). The intensive use of water in
mining and metallurgy is one of the characteristics of this activity and goes from the initial research phase to the processing and production of metal. Tailings residues from processing and mining can impact surface and groundwater resources (Ciminelli 2010).
The other issue regarding mining is the use of the mineral differential to establish a new stage of economic development and sustainability based on territorial management; in other words, the proposal is not to act on remediation after the impact, but to anticipate impacts, integrate water resources management with research and development, and reconcile mining with natural resource conservation and integrated water resources management. More efficient uses of water resources that reduce consumption specifically in mining, waste treatment, and reducing the volume and load of mining effluents are necessary and strategic advances that depend on innovation, research and the integrated management of natural resources (INCT 2010).
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