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

The Machemont wastewater treatment plant is located in the commune of Machemont, within the Oise department of the Hauts-de-France region in northern France. The facility serves a population of approximately 2,108 residents, classifying it as a small agglomeration under French and EU regulations. The plant employs advanced treatment processes, which go beyond the EU Urban Waste Water Treatment Directive's minimum requirement of secondary treatment for inland freshwater discharges. With a designed capacity of 3,000 cubic meters per day and an average daily flow of 376 cubic meters, 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 Oise River, a major tributary of the Seine. The Seine River flows through Paris and into the English Channel, making the plant's advanced treatment important for protecting downstream water quality and the sensitive estuarine and coastal ecosystems of the Seine Bay.

The plant discharges into the Oise River basin, which flows into the Seine River and eventually reaches the English Channel. The Seine estuary and Bay of Seine support diverse aquatic life, including migratory fish species such as Atlantic salmon and European eel. Advanced treatment at this plant helps reduce nutrient loads that could contribute to eutrophication in the coastal zone.