Lewin Brzeski Wastewater Treatment Plant, Niwnica, Opole Voivodeship, Poland

The Lewin Brzeski wastewater treatment plant is located in Niwnica, a village in the Opole Voivodeship of southern Poland. It serves a population of 1,906, classifying it as a small agglomeration under Polish and EU regulations. The plant is situated inland, away from coastal areas, and its operations are part of the regional wastewater infrastructure managed by local authorities. The facility provides secondary treatment, which is the minimum standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The plant has a designed capacity of 8,605 m³/day and currently discharges 271.77 m³/day, indicating significant spare capacity. As a Polish facility, it operates under the national implementation of EU directives, overseen by the Regional Water Management Board (RZGW) in Wrocław. The treated effluent is discharged into a local watercourse that eventually flows into the Oder River basin. The Oder River is a major European waterway that drains into the Baltic Sea. The plant's secondary treatment helps protect the Oder's water quality and the downstream ecosystems, including the Szczecin Lagoon and the Baltic Sea, from nutrient pollution and organic load.

The plant discharges into a tributary of the Oder River, which flows northward through Poland and Germany before emptying into the Szczecin Lagoon and the Baltic Sea. The Oder basin supports diverse aquatic life and is an important migratory corridor for fish. Secondary treatment reduces organic pollutants and nutrients, helping to mitigate eutrophication in the Baltic Sea, a sensitive marine environment.