A series of articles published in this issue of AURA presents the quality of water abstracted for Wrocław, Cracow and Warsaw; the situation of the Sulejowski Reservoir, a water supply source for Łódź is also discussed. Water for these conurbations is abstracted from rivers and dammed reservoirs. Its chemical composition reflects water purity in Poland. In the best case, the abstracted water can be classified to class II water purity. Low quality of raw water elevates costs of water treatment: it does not guarantees good quality, either. Water supplied by Wrocław supply system comes from two tributaries of the Oder River: Oława and Nysa Kłodzka. Water quality does not meet requirements for class I water purity. Secondary water contamination in the water supply network and internal installations in houses is another issue. This results in deterioration in smell and taste and causes very adverse opinions on quality of supplied water.