Żabia Wola Wastewater Treatment Plant, Kaleń, Poland

The Żabia Wola wastewater treatment plant is located in Kaleń, within the gmina of Żabia Wola in the Mazowieckie Voivodeship of Poland. It serves a small population of 225 residents, reflecting its role in a rural or suburban community. The plant is part of Poland's municipal wastewater infrastructure, which operates under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant provides secondary treatment, which is the standard biological treatment required by the EU directive for agglomerations of this size. With a designed capacity of 4166 m³/day, the plant has significant headroom for future growth, as current discharge volume is only 32.08 m³/day. This suggests the plant is designed to accommodate population increases or seasonal variations. The treated effluent is discharged into local watercourses that ultimately drain into the Vistula River basin, which flows northward into the Baltic Sea. The plant's operation helps protect downstream aquatic ecosystems from nutrient pollution and organic loading, supporting water quality in the region's rivers and the Baltic Sea.

The plant discharges into local streams that are part of the Vistula River basin. The Vistula flows through central Poland and empties into the Baltic Sea via the Gdańsk Bay. The Baltic Sea is a semi-enclosed brackish sea sensitive to nutrient inputs, making effective wastewater treatment crucial for preventing eutrophication. The plant's secondary treatment reduces organic matter and nutrients, helping to maintain the ecological health of the downstream water bodies.