Niedrzwica Wastewater Treatment Plant, Niedrzwica Duża, Poland

The Niedrzwica wastewater treatment plant is located in Niedrzwica Duża, a town in the Lublin Voivodeship of eastern Poland. The facility serves a population of approximately 2,500 people and operates under Poland's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC). As a small agglomeration, it is subject to national regulations that require appropriate treatment before discharge. The plant provides secondary treatment, which is the standard biological treatment stage for removing organic matter and suspended solids. With a designed capacity of 3,339 m³/day, the current discharge volume of 356.03 m³/day indicates the plant is operating well below its capacity. The facility is managed as part of the municipal wastewater infrastructure for the local community. The treated effluent is discharged into local watercourses that eventually drain into the Vistula River basin, which flows northward to the Baltic Sea. The plant plays a key role in protecting the region's surface waters from untreated sewage, supporting aquatic life and downstream water quality in the Lublin region.

The plant discharges into local streams that are part of the Vistula River basin, ultimately reaching the Baltic Sea. The surrounding Lublin region features agricultural landscapes and small water bodies that are sensitive to nutrient pollution. Secondary treatment helps reduce organic load and nutrients, protecting downstream ecosystems from eutrophication and maintaining water quality for biodiversity.