OTHIS Wastewater Treatment Plant, Othis, Île-de-France, France

OTHIS is a municipal wastewater treatment plant located in Othis, a commune in the Seine-et-Marne department of Île-de-France, France. The plant serves a population equivalent of 5,820, placing it in the small agglomeration category under the EU Urban Waste Water Treatment Directive (91/271/EEC). As part of the Île-de-France region, the plant contributes to the management of wastewater in the greater Paris metropolitan area. Under the EU UWWTD, agglomerations with a population equivalent between 2,000 and 10,000 are required to provide secondary treatment (biological treatment) unless the receiving waters are designated as sensitive areas, which may require more stringent treatment. The regulatory framework ensures compliance with national and European standards for effluent quality. The treated effluent from OTHIS is discharged into local watercourses that ultimately drain into the Seine River basin. The Seine flows through Paris and into the English Channel, supporting diverse aquatic life and serving as a critical water resource for the region. The plant plays a key role in protecting the Seine's water quality and the downstream estuarine and marine environments.

The OTHIS plant discharges into the Seine River basin, which drains a large portion of northern France. The Seine River flows through Paris and eventually reaches the English Channel, supporting a variety of fish species and providing habitat for migratory birds. The downstream environment includes the Seine estuary, an ecologically sensitive area that supports diverse aquatic life and is important for nutrient cycling and sediment transport. The plant's operations help reduce nutrient and pollutant loads entering this vital waterway.