ROWP Suplacu de Barcau Wastewater Treatment Plant, Suplacu de Barcău, Bihor, Romania

ROWP Suplacu de Barcau is a municipal wastewater treatment plant located in Suplacu de Barcău, Bihor County, Romania. The facility serves a small population of 690 residents, reflecting the rural character of the area. It operates under Romania's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which sets treatment standards based on agglomeration size and receiving water sensitivity. The plant provides secondary treatment, a standard requirement under the EU directive for inland freshwater discharges from agglomerations of this scale. With a designed capacity of 3845 m³/day and an actual discharge volume of 528.34 m³/day, the plant operates well below its capacity, indicating room for future growth. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into a local watercourse that eventually drains into the Crișul Repede River, part of the Tisza River basin, which flows into the Danube and ultimately the Black Sea. This connection highlights the plant's role in protecting downstream water quality in a transboundary river system that supports diverse aquatic life and agricultural uses.

The plant discharges into a tributary of the Crișul Repede River, which flows through northwestern Romania into Hungary, joining the Tisza River. The Tisza is a major tributary of the Danube, which empties into the Black Sea. This watershed supports diverse aquatic ecosystems and is important for regional biodiversity, including fish species and migratory birds. The secondary treatment provided helps reduce nutrient and organic pollution, protecting downstream water quality in this sensitive river network.