Some of the environmental and social impacts that are shown after the closure of a mine include the loss of aquifers, the existence of surface water contaminated with chemicals and the effects on health of people living near abandoned mines. This research aims to analyze the main legal aspects related to the completion and closure of the mine from socially and environmentally. In order to do that, it sets out the major environmental and social impacts that arise from the termination; then the most important legal aspects of mining concession contracts and environmental license are shown; Then the legal obligations that are the responsibility of both, the mining concessionary and the competent authority for the closure of the mine and the role assumed by the control agencies is examined. Also there is a brief analysis, in comparative law, of regulation in Spain and the United States about this issue. Finally the results set out from the administrative records, provided by the National Mining Agency, in which the application and enforcement in practice of these legal obligations of the mining concessionary one the contract ends. Based on the results it can be concluded, first, that the obligations of the mining concessionary are poorly determined by the mining and environmental regulation, secondly that the regulation regarding the closure of mines in Spain and the United States is more organized, complete and specific, and third regarding the six cases examined, it can be seen that the mining concessionary and the authorities did not comply their obligations.
