Leczyce Wastewater Treatment Plant, Połupino, Pomeranian Voivodeship

The Leczyce wastewater treatment plant is located in Połupino, within the gmina Czarna Dąbrówka in the Pomeranian Voivodeship of northern Poland. It serves a population of 3,168 and operates as a secondary treatment facility, meeting the standards required for smaller agglomerations under Polish and EU regulations. The plant has a designed capacity of 5,500 m³/day and currently discharges an average of 451.71 m³/day of treated wastewater. As a secondary treatment plant, it provides biological treatment to reduce organic matter and suspended solids, in line with the EU Urban Waste Water Treatment Directive (91/271/EEC) which mandates secondary treatment for agglomerations of this size. The treated effluent is discharged into local watercourses that drain into the Baltic Sea via the Słupia River basin. The plant plays a key role in protecting the region's surface waters and the downstream coastal environment from nutrient pollution, supporting the ecological health of the Baltic Sea.

The Leczyce plant discharges into local streams that flow into the Słupia River, which ultimately reaches the Baltic Sea. The Baltic Sea is a semi-enclosed, brackish sea sensitive to eutrophication from nutrient inputs. The plant's secondary treatment helps reduce organic and nutrient loads, contributing to the protection of downstream aquatic ecosystems and coastal water quality.