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

The Crézancy wastewater treatment plant is located in the commune of Crézancy, within the Aisne department of the Hauts-de-France region in northern France. This facility serves a population of approximately 1,678 residents, placing it in the small agglomeration category under French and EU regulations. The plant 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 2,250 m³/day and an average discharge volume of 299.35 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into the local watershed, which ultimately drains into the Marne River basin and then into the Seine River. This region is part of the Seine-Normandy water basin, an ecologically important area that supports diverse aquatic life and contributes to the water quality of the English Channel.

The plant discharges into the local watercourse that flows into the Marne River, a major tributary of the Seine River. The Seine basin is a densely populated and agriculturally intensive region, making advanced treatment crucial for protecting downstream water quality. The area supports diverse freshwater ecosystems, including fish populations and riparian habitats, and the Seine estuary is an important migratory corridor for birds.