UWWTP_ORMOz Wastewater Treatment Plant, Otok Virje, Croatia

UWWTP_ORMOz is a wastewater treatment plant located in Otok Virje, within the Varaždinska županija of northern Croatia. The plant serves a population of approximately 5034 people, classifying it as a small to medium agglomeration under EU standards. It is situated inland, away from the coast, and its operations are part of Croatia's compliance with the EU Urban Waste Water Treatment Directive. The plant provides secondary treatment, which is the minimum required for agglomerations of this size under the EU UWWTD. With a designed capacity of 4000 m³/day and a discharge volume of 472.58 m³/day, the plant operates well below its capacity, indicating potential for future growth or seasonal variability. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into a local water body, likely a tributary of the Drava River, which flows into the Danube and ultimately the Black Sea. The plant plays a role in protecting the regional water quality and supporting the ecological health of the Drava basin, which is important for biodiversity and agriculture in the region.

The plant discharges into a local watercourse that feeds into the Drava River, a major tributary of the Danube. The Drava basin supports diverse aquatic life and is an important ecological corridor in Central Europe. The Danube eventually flows into the Black Sea, making the plant's treatment performance relevant to downstream water quality across multiple countries.