Siechnice Wastewater Treatment Plant: Secondary Treatment Serving Siechnice, Poland

The Siechnice wastewater treatment plant is located in the town of Siechnice, within województwo dolnośląskie (Lower Silesian Voivodeship) in southwestern Poland. The facility serves a population of approximately 6,074 residents, classifying it as a small to medium agglomeration under Polish and EU regulations. The plant provides secondary treatment, which is the minimum standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for inland discharges from agglomerations of this size. The designed capacity of 13,146 m³/day indicates the plant is sized to accommodate future growth, while the current discharge volume of 866.06 m³/day suggests significant spare capacity. The treated effluent is discharged into the local watershed, which ultimately drains into the Odra River basin. The Odra River flows northward to the Baltic Sea, passing through ecologically sensitive areas that support diverse aquatic life. The plant's secondary treatment helps protect downstream water quality in this transboundary river system.

The plant discharges into the Odra River basin, which flows through southwestern Poland and eventually reaches the Baltic Sea via the Szczecin Lagoon. The Odra is a major European river supporting diverse fish populations and migratory bird species. Secondary treatment reduces organic load and suspended solids, helping to maintain water quality in this ecologically important watershed.