Mine drainage and discharge of salt waters into water bodies belong to main environmental issues, which must be appropriately addressed by the underground coal mining industry. The large area of exploited and abandoned mine fields in the Upper Silesia Coal Basin, as well as the geological structure of the rock mass and its hydrogeological conditions require the draining and discharge of about 119 million m3/yr of mine waters. Increasing the depth of mining and the necessity of protection of mines against water hazard result in increased amounts of chlorides and sulphates in the mine waters, even by decreasing the total coal output and the number of mines. The majority of the salts are being discharged directly into rivers, partly under control of salt concentration, however from the point of the view of environment protection, the most favorable way of their utilization would be technologies allowing the bulk use of saline waters. Filling of underground voids represents a group of such methods, from which the filling of goaves (cavings) is the most effective. Due to large volume of voids resulting from the extraction of coal and taking the numerous limitations of this method into account, the potential capacity for filling reaches about 17.7 million m3/yr of cavings and unnecessary workings. Considering the limited availability of fly ash, which is the main component of slurries being in use for the filling of voids, the total volume of saline water and brines, which could be utilized, has been assessed as 3,5–6,5 million m3/yr

The shortage of investment areas may be at least partially satisfied by the development of reclaimed post-mining areas. These are often subsidence zones levelled with hard coal mine waste or reclaimed sub-level old dumps of this waste. From the geotechnical point of view, such grounds represent anthropogenic grounds containing mine waste, and they are considered as possessing unfavourable properties in terms of the foundation of building structures. The paper initially presents the analysis of the properties of waste from the hard coal mining industry, emphasising that they expose several beneficial properties enabling their safe use. The second part of the article is devoted to the determination of soil density using the DPSH probe. It has been found that the applicable standards lack complex relationships that would allow for a reliable interpretation of the measurement results in a wide range of soil types. The last part presents exemplary results of measurements made with the DPSH probe at a construction site. The obtained results allowed for the formulation of several conclusions regarding the possibility of building on a ground made of hard coal waste and the use of dynamic sounding to assess the geotechnical properties of such anthropogenic soil.