Mrocza Wastewater Treatment Plant - Secondary Treatment in Kuyavian-Pomeranian Voivodeship, Poland

The Mrocza wastewater treatment plant is located in the town of Mrocza, within the Kuyavian-Pomeranian Voivodeship of Poland. It serves a population of approximately 5,617 residents, classifying it as a small agglomeration under Polish and EU regulations. The plant operates under the framework of the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The plant provides secondary treatment, which typically involves biological processes to reduce organic matter and suspended solids. Its designed capacity is 8,755 m³/day, while the current discharge volume is 800.90 m³/day, indicating that the plant operates well below its capacity. As a secondary treatment facility, it meets the EU directive's minimum requirements for inland discharges. The treated effluent is discharged into local watercourses that ultimately drain into the Baltic Sea via the Vistula River basin. The plant plays a key role in protecting the region's water quality, supporting aquatic life in downstream rivers and contributing to the ecological health of the Baltic Sea.

The Mrocza plant discharges into the local river network, which flows into the Noteć River, a tributary of the Warta River, and eventually reaches the Oder River estuary and the Baltic Sea. The Baltic Sea is a semi-enclosed sea with limited water exchange, making it sensitive to nutrient pollution. The plant's secondary treatment helps reduce organic loads and nutrients, supporting the ecological balance of the downstream aquatic environment.