The mechanical and biological treatment plant in Wis?a Wielka was built to collect and treat sewage in the drainage area of the Goczałkowice drinking water reservoir. The plant is able to receive and treat 730 m3/day. Now it collects sewage from Wisła Wielka, Wisła Mała and Łąka, however, the target for it is to treat sewage from the whole area of the western part of the Pszczyna Commune, which is in the drainage area of the Goczałkowice dam reservoir (the river Vistula) and the Łąka reservoir (the river Pszczynka), after extension of the sanitary sewerage system.