Knyszyn Wastewater Treatment Plant - Podlaskie, Poland

The Knyszyn wastewater treatment plant is located in the town of Knyszyn, in the Podlaskie Voivodeship of northeastern Poland. It serves a population of approximately 3,035 people, classifying it as a small agglomeration under Polish and EU regulations. The plant is situated on Tykocka Street and operates as a key municipal facility for the local community. As a secondary treatment plant, Knyszyn meets the minimum requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The directive mandates secondary treatment for all discharges from agglomerations with a population equivalent (PE) between 2,000 and 10,000, unless the receiving waters are designated as sensitive areas requiring more advanced treatment. The plant's designed capacity of 6,000 m³/day indicates it has room to accommodate future growth. The treated effluent from Knyszyn is discharged into local waterways that ultimately drain into the Narew River basin, a major tributary of the Vistula River flowing into the Baltic Sea. The region is characterized by agricultural landscapes and small watercourses, making the plant's role in protecting surface water quality important for both local ecosystems and downstream environments.

The Knyszyn plant discharges into the Narew River basin, which flows through northeastern Poland and eventually joins the Vistula River before reaching the Baltic Sea. The Narew is a lowland river with extensive floodplains and wetlands that support diverse aquatic life and migratory bird populations. The plant's secondary treatment helps reduce organic pollution and nutrient loads, contributing to the ecological health of this sensitive river system.