Osie Wastewater Treatment Plant, Radańska, Poland - Secondary Treatment for 4,753 People

The Osie wastewater treatment plant is located in Radańska, within the gmina Osie in the kujawsko-pomorskie voivodeship of Poland. It serves a population of approximately 4,753 people, classifying it as a small to medium agglomeration under Polish and EU regulations. The plant is situated inland, away from coastal areas, and its operations are part of the regional water management infrastructure. Osie provides secondary treatment, which is the standard requirement under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size discharging into freshwater. The plant has a designed capacity of 9,000 m³/day and currently treats an average daily flow of 677.70 m³/day, indicating ample reserve capacity. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into local watercourses that eventually drain into the Vistula River basin, which flows into the Baltic Sea. The plant plays a key role in protecting the region's surface waters from pollution, supporting aquatic life and downstream water quality. Its operation is subject to Polish environmental permits aligned with EU directives.

The plant discharges into local streams that are part of the Vistula River basin, Poland's largest river system, which ultimately flows into the Baltic Sea. The watershed supports diverse aquatic habitats and is important for migratory fish species. The region's water quality is managed under the EU Water Framework Directive, aiming for good ecological status.