Warluis Wastewater Treatment Plant, Hauts-de-France, France

The Warluis wastewater treatment plant is located in the commune of Warluis, within the Oise department of the Hauts-de-France region in northern France. It serves a population of approximately 1,875 residents, classifying it as a small agglomeration under French and EU regulations. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. Its designed capacity is 2,000 m³ per day, with an average daily flow of 334.5 m³, indicating ample reserve capacity. The treated effluent is discharged into a local watercourse that ultimately flows into the Oise River, a major tributary of the Seine. The Seine basin supports diverse aquatic life and is an important ecological corridor in northern France. The plant's operation helps protect downstream water quality in this densely populated region.

The plant discharges into a small stream that feeds the Oise River, which flows into the Seine River and eventually the English Channel. The Seine basin is ecologically significant, supporting fish species such as Atlantic salmon and European eel, and providing habitat for migratory birds. The plant's secondary treatment reduces organic pollution and helps maintain the ecological balance of the watershed.