This master thesis is dedicated to the complex mining, legal, and socio-ecological challenges associated with the repurposing of the Weitendorf basalt quarry as part of the "Sonnenspeicher Süd" project, which aims to transform the site into a future thermal energy storage facility. The goal of this groundbreaking project is to store heat generated by solar thermal energy in a large-volume water reservoir (formed out of the closed basalt quarry) and utilize it efficiently during the heating season. The thesis addresses the geological and, in particular, the geotechnical challenges of the site, the necessary legal approvals, as well as the ecological and societal impacts, and finally, the acceptance of the project by the local community. A key aspect of the thesis is the planning of the final open-pit configuration, especially focusing on the various phases and the necessary blasting techniques required to achieve the final pit contour. The socio-ecological aspects of this thesis primarily examine potential underground warming due to the hot water, as well as possible impacts on the groundwater body. In addition, within the context of exploring the Social License to Operate (SLO) for the project, various measures are outlined to ensure broad acceptance among the affected community.