Support tools for groundwater management in the proximity of a mine site

Resumen

The natural environment in which we live, is subjected, to a greater or lesser extent, to the pressure of human activity, with water being one of the most sensitive elements. For this reason, aware of this situation, from all the forums (Administration, Companies and stakeholders) is imposing the practice new standards unthinkable during the decades of industrial development, aimed at making the environment and industry compatible. A new model of mining seeks to achieve a balance between good environmental practices and efficiency, so that production is linked to environmental respect. The Niebla-Posadas aquifer (NP) constitutes one of the water resources within the Guadalquivir Basin, which supports traditional agriculture in the area and is the source of drinking water for many populations. In recent decades, competition for this resource has increased due to the expansion of irrigated agriculture and in turn affected by the development of mining activity with the opening of the Cobre Las Cruces mine (CLC). The CLC is one of Europe's largest open pit copper mine which has implemented pioneering water management methodologies in the mining industry. One of the highlights of this methodology is the Drainage and Reinjection system (DRS) for groundwater near the mining activity. The DRS allows the drainage of the groundwater before it can appear in the open pit, through a set of wells surrounding it. Moreover, once treated to meet environmental requirements, this water is reinjected into the aquifer through another set of wells surrounding the extraction wells. In addition, groundwater in the vicinity of the CLC presents poor natural quality, so they are unsuitable for direct use without previous treatment. High natural concentrations of some components, initially alerted the public opinion. Nevertheless, today it has been demonstrated that this is not due to mining activity but to natural processes. The general goal of this thesis is to provide a series of tools to improve the methodology of groundwater management in a mining environment. Development of a methodological framework is of great interest and may constitute a support tool for sustainable management and protection of groundwater resources affected by mining activities. All these methodological issues are focused on and applied to the CLC, which has allowed validation of joint use to ascertain and quantify the hydrodynamic aspects of the groundwater at mine sites and definition of the bases for sustainable water resource management in the area.