BOS 100 Wastewater Treatment Plant, Stawiszcze, Podlaskie Voivodeship

BOS 100 is a municipal wastewater treatment plant located in Stawiszcze, a village in the Podlaskie Voivodeship of northeastern Poland. The plant serves a small population of 419 residents and is part of the local wastewater infrastructure managed under Polish environmental regulations. The plant provides secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 900 m³/day and a current discharge volume of 59.74 m³/day, the facility operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into local watercourses that eventually drain into the Bug River basin, a major tributary of the Vistula River. The Bug River flows northward into the Baltic Sea, making the plant's performance important for downstream water quality in this transboundary river system.

The plant discharges into the Bug River catchment, which flows through Poland, Belarus, and Ukraine before joining the Narew River and ultimately the Vistula River, which empties into the Baltic Sea. The Bug River supports diverse aquatic life and is an important ecological corridor in the region. The surrounding area is characterized by agricultural land and forests, with sensitive ecosystems that benefit from proper wastewater treatment to prevent nutrient pollution.