ST VENANT SE Wastewater Treatment Plant, Saint-Venant, Hauts-de-France

ST VENANT SE is a municipal wastewater treatment plant located in Saint-Venant, a commune in the Pas-de-Calais department of the Hauts-de-France region, northern France. The plant serves a population of approximately 2,800 residents, placing it in the small agglomeration category under French and EU regulations. The facility employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 3,600 m³/day and an average daily discharge of 499.52 m³/day, the plant operates well below its capacity, indicating potential for future growth or seasonal variations. The treated effluent is discharged into local waterways that ultimately drain into the North Sea via the Lys River and Scheldt basin. The plant plays a key role in protecting the region's water quality, supporting aquatic life in the downstream river systems and contributing to the ecological health of the North Sea coastal zone.

The plant discharges into the local river network, which flows into the Lys River, a tributary of the Scheldt, and eventually reaches the North Sea. This watershed supports diverse aquatic habitats and is important for migratory fish species. The advanced treatment helps reduce nutrient loads, protecting downstream water bodies from eutrophication and maintaining water quality for both ecological and recreational uses.