Zakrzewki Wastewater Treatment Plant, Dobroń, Łódź Voivodeship

Zakrzewki wastewater treatment plant is located in the village of Zakrzewki, within the municipality of Dobroń in the Łódź Voivodeship of central Poland. The plant serves a population of 3,208, classifying it as a small agglomeration under Polish and EU regulations. It operates secondary treatment, which is the minimum standard required by the EU Urban Waste Water Treatment Directive for inland freshwater discharges from agglomerations of this size. The plant has a designed capacity of 3,630 cubic meters per day and currently treats an average daily flow of 457.41 cubic meters, indicating significant spare capacity. As a secondary treatment facility, it employs biological processes to reduce organic matter and suspended solids, meeting the effluent standards set by Polish water law transposing the EU directive. The treated effluent is discharged into local watercourses that ultimately drain into the Warta River basin, a major tributary of the Oder River system flowing into the Baltic Sea. The plant plays a key role in protecting the region's surface waters from nutrient pollution and supporting the ecological health of the downstream aquatic environment.

The plant's discharge enters small streams within the Warta River catchment, which flows northward through central Poland before joining the Oder River near Kostrzyn nad Odrą. The Oder then empties into the Szczecin Lagoon and the Baltic Sea. The region's waters support diverse aquatic life, including fish species such as pike and bream, and the plant's secondary treatment helps reduce organic loading and nutrient inputs that could otherwise contribute to eutrophication in downstream water bodies.