Jiu Valley is in an extensive transition process from an area rich in coal deposits to an area with 0 Carbon emissions. Coal mining was carried out in 14 mining perimeters arranged along the Jiu Valley. At the same time, the extraction of the useful mineral substance resulted in waste material that was stored in tailings dumps. Out of the total of 49 landfills, 25 have been greened, 15 are inactive and 9 are active. The total area occupied by them is approximately 210 ha, arranged near mining operations, in the valleys of some streams and even in the vicinity of human settlements. The paper aims to identify the potential for soil contamination due to inactive tailings dumps.