Krypno Wastewater Treatment Plant, Krypno Wielkie, Poland

The Krypno wastewater treatment plant is located in Krypno Wielkie, a village in the podlaskie province of northeastern Poland. It serves a population of approximately 2,110 residents, classifying it as a small agglomeration under Polish and EU regulations. The facility is part of the municipal infrastructure managed by the local gmina (municipality). The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size in non-sensitive areas. It has a designed capacity of 3,860 m³/day and currently treats an average daily volume of 300.85 m³, indicating significant spare capacity. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into a local watercourse, likely a tributary of the Narew River, which flows into the Vistula and eventually to the Baltic Sea. The plant plays a key role in protecting the local aquatic environment and downstream ecosystems from untreated wastewater pollution.

The plant discharges into a small water body that drains into the Narew River basin, a major tributary of the Vistula River. The Vistula flows northward into the Baltic Sea via the Gulf of Gdańsk. The region's watershed supports diverse aquatic life and is part of an ecologically sensitive area, including wetlands and floodplains that provide habitat for migratory birds and fish species. Proper wastewater treatment is essential to prevent nutrient enrichment and maintain water quality in this important Baltic Sea catchment.