SENLIS Wastewater Treatment Plant, Senlis, Hauts-de-France, France

The SENLIS wastewater treatment plant is located in Senlis, within the Hauts-de-France region of northern France. It serves a population equivalent of approximately 27,174, classifying it as a medium-sized agglomeration under EU regulations. The plant is situated near the Nonette River, a tributary of the Oise, which flows into the Seine and eventually the English Channel. As a French facility, the plant operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations between 10,000 and 150,000 population equivalent. For sensitive areas, tertiary treatment may be mandated. The regulatory framework ensures compliance with discharge standards to protect receiving waters. The treated effluent is discharged into the Nonette River, which feeds into the Oise and Seine river system. This waterway supports diverse aquatic life and is an important ecological corridor in the Paris Basin. The Seine ultimately drains into the English Channel, making the plant's performance relevant to both local and downstream water quality.

The SENLIS plant discharges into the Nonette River, a tributary of the Oise, which flows into the Seine River and then the English Channel. This watershed supports diverse aquatic ecosystems and is used for recreation and agriculture. The Seine estuary is ecologically sensitive, hosting migratory fish species and important bird populations. Effective treatment at SENLIS helps protect these downstream environments from nutrient pollution and pathogens.