Summary:

The paper deals with an issue of closing small communal dumping sites for municipal wastes that, for various reasons, could not meet the legal regulations in force since 2003. One of such dumping grounds is situated in Chełmek Commune, in the west part of Malopolska Voivodship. The currently lasting process of closing it and reclamation encounters problems resulting from technical design as-sumptions of the seventieth. The question of geotechnical stability of the slope of the inclination 1:1 was analysed it the article. An influence of changes of the values of the angle of internal friction of wastes on the obtained values of the safety factor was determined using Bishop's method. The analysis concerns also the influence of the outside load that can occur on the crest of the landfill quarter as well as ground-water conditions in the subsoil.
Data for stability calculations were compiled on the basis of the carried out in-situ tests as well as the existing documents concerning the dumping site. The obtained results of calculations show the existing risk of the slope stability loss in the case of certain assumed values of geotechnical parameters and outside loads. There were assumed, for the considered dumping site, three characteristic compu-tational cases, taking into account variety of chosen geotechnical parameters and outside loads. In the case of favourable groundwater conditions, the risk of the loss of the stability is not big, whereas when the subsoil and the slope are saturated, the values of the safety factor show the risk of the slope stability loss.