MAIGNELAY MONTIGNY Wastewater Treatment Plant, Montiers, Hauts-de-France

MAIGNELAY MONTIGNY is an advanced wastewater treatment plant located in Montiers, within the Oise department of Hauts-de-France, France. The plant serves a population of 4,833, placing it in the small agglomeration category under French regulations. It is situated inland, away from coastal areas, and its treated effluent is discharged into local watercourses. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. Its designed capacity is 3,000 cubic meters per day, and it currently discharges an average of 862.20 cubic meters per day, indicating operational headroom. As a French facility, it operates under the national transposition of the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires appropriate treatment for agglomerations of this size. The treated wastewater from MAIGNELAY MONTIGNY ultimately flows into the Oise River basin, a tributary of the Seine River, which drains into the English Channel. The plant plays a key role in protecting the local watershed and downstream aquatic ecosystems, including the Seine estuary, by reducing pollutant loads from the Montiers area.

The plant discharges into the Oise River basin, which flows into the Seine River and eventually reaches the English Channel. This watershed supports diverse aquatic life and is important for regional water quality. The advanced treatment helps protect downstream ecosystems, including the Seine estuary, from nutrient enrichment and other pollutants.