ROWP Primaria Roiesti sat Cuien Wastewater Treatment Plant, Cueni, Vâlcea County

ROWP Primaria Roiesti sat Cuien is a municipal wastewater treatment plant located in Cueni, a village in Vâlcea County, Romania. The plant serves a small population of 297 residents, reflecting its role in a rural community. It operates under Romania's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which sets standards for wastewater treatment based on agglomeration size. The plant provides secondary treatment, which is appropriate for its small scale. Its designed capacity is 2,500 m³/day, and it currently discharges an average of 78.52 m³/day of treated effluent. As a facility serving fewer than 2,000 population equivalent, it falls under the directive's less stringent requirements, but secondary treatment ensures significant reduction of organic matter and suspended solids. The treated effluent is discharged into a local watercourse that eventually drains into the Olt River, a major tributary of the Danube. The Danube then flows into the Black Sea. The plant's operation helps protect downstream water quality in this ecologically important river system, which supports diverse aquatic life and is used for agriculture and recreation.

The plant discharges into a small stream that flows into the Olt River, a major tributary of the Danube. The Olt River basin supports diverse aquatic ecosystems and is an important corridor for migratory fish species. The Danube eventually reaches the Black Sea, a semi-enclosed sea with sensitive marine environments. Proper wastewater treatment at this plant helps reduce nutrient and pollutant loads that could contribute to eutrophication in downstream waters.