Centralna Oczyszczalnia Sciekow w Kozieglowach - Major Wastewater Treatment Plant in Czerwonak, Poland

Centralna Oczyszczalnia Sciekow w Kozieglowach is a large wastewater treatment plant located in Czerwonak, near Poznan, in the Wielkopolskie region of Poland. It serves a population of over 1.3 million, making it one of the largest agglomerations in the country. The plant is a key component of the regional wastewater infrastructure, handling municipal sewage from the Poznan metropolitan area. As a large agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC), the plant is required to provide at least secondary treatment, with more stringent requirements if the receiving waters are sensitive. The directive mandates that agglomerations over 150,000 population equivalent must achieve advanced treatment in sensitive areas. The plant's scale and regulatory context ensure it meets high environmental standards. The treated effluent is discharged into local water bodies that ultimately drain into the Warta River, a major tributary of the Oder River, which flows into the Baltic Sea. The plant plays a crucial role in protecting the Warta River basin and the Baltic Sea from nutrient pollution, supporting aquatic ecosystems and water quality downstream.

The plant discharges into the Warta River basin, which flows into the Oder River and eventually the Baltic Sea. The Baltic Sea is a brackish inland sea sensitive to eutrophication from nutrient inputs. The plant's advanced treatment helps reduce nitrogen and phosphorus loads, protecting the ecological balance of the Warta River and downstream marine environment.