Four small (surface area: 0.4-2.3 ha), but relatively deep (max. depth: 6.5-7.8 111) man made reservoirs, created between 1979 and 1988 on recultivatccl waste heap of former sulphur mine in Machów (N 50°31'35": E 21°37'51")_ were studied in summer and autumn 2003. In autumn one lake - Kacze was not mixed down to the bottom, which could point to its meromixis. The other lakes were found to be dimictic. In all the lakes high values of total hardness, conductivity, chlorides, sulphides and low amounts 01· total phosphorus and nitrogen were found. Both phytoplankton and hydrornacrophyte communities were poorly developed. Considerable amounts or green-yellow bacteria were also noted in plankton The water chemistry as well as quantity and quality of plant communities reflect the chemical composition of loam soils which constitute the waste heap.