ROWP CL Caiuti Wastewater Treatment Plant, Căiuți, Bacău, Romania

ROWP CL Caiuti is a municipal wastewater treatment plant located in Căiuți, Bacău County, Romania. The facility serves a population of approximately 5,629 people, classifying it as a small agglomeration under Romanian and EU regulations. The plant is situated on Strada Primăverii and operates under Romania's implementation of the EU Urban Waste Water Treatment Directive. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive for freshwater discharges from agglomerations of this size. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The designed capacity is 5,804 m³/day, with a reported discharge volume of 5.27 m³/day, indicating the plant operates well below its design capacity. The treated effluent is discharged into local watercourses that eventually drain into the Siret River basin, a major tributary of the Danube. The Danube then flows into the Black Sea. The plant plays a key role in protecting the local watershed from untreated sewage, supporting aquatic life and downstream water quality in the Siret and Danube ecosystems.

The plant discharges into the Siret River basin, which flows into the Danube River and ultimately the Black Sea. The Siret is an ecologically significant river supporting diverse fish species and migratory birds. The plant's secondary treatment helps reduce nutrient and organic pollution, mitigating eutrophication risks in downstream water bodies.