Dziemionna Wastewater Treatment Plant, Chmielniki, Poland

The Dziemionna wastewater treatment plant is located in Chmielniki, within the gmina of Nowa Wieś Wielka in the kujawsko-pomorskie province of Poland. It serves a population of 3,135, classifying it as a small agglomeration under Polish and EU regulations. The plant provides secondary treatment, which is the minimum standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. As a secondary treatment facility, Dziemionna uses biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 3,267 m³/day and currently treats an average daily volume of 447 m³, indicating significant spare capacity. This suggests the plant is well-equipped to handle future population growth or increased industrial loads in the area. The treated effluent is discharged into local surface waters, which ultimately drain into the Vistula River basin and then into the Baltic Sea. The plant plays a key role in protecting the region's water quality, particularly in the context of the Baltic Sea's vulnerability to eutrophication from nutrient pollution. By meeting EU standards, Dziemionna helps reduce the nutrient load entering the Baltic ecosystem.

The Dziemionna plant discharges into local streams that are part of the Vistula River basin, the largest river system in Poland. The Vistula flows northward into the Baltic Sea, a semi-enclosed sea highly sensitive to nutrient inputs. The region's agricultural activity contributes to diffuse pollution, making the plant's secondary treatment essential for controlling point-source nutrient loads. The downstream environment supports diverse aquatic life and is an important migratory corridor for fish species.