Two water adits that drain the old, closed excavation tanks of a coal mine were characterized in terms of the physical-chemical properties of their waters and compared them with the waters of two springs. These adits are “Krystyna” and “318,” and the springs are Maria and Mniszek, which are situated in the Upper Silesian Region (sothern Poland). The results that were obtained permitted us to infer that acid drainage can occur within the pits. Thus, the waters of the adits are acid and typified by a high concentration of sulphates and iron ions. A distinguishing feature of the “318” adit is its high thermal stability. The variation in temperature during the year does not exceed 1°C. The springs flow from Carbon sandstone and therefore, they functioned as reference samples for the adits that were investigated. A high synchronicity of changes in the selected physical-chemical parameters of adit waters and natural springs was observed.