Gasny Nouvelle STEP - Advanced Wastewater Treatment in Gasny, Normandy

Gasny Nouvelle STEP is a municipal wastewater treatment plant located in Gasny, a commune in the Eure department of Normandy, France. The plant serves a population of about 3,870 and has a design capacity of 6,000 m³/day, with an average daily discharge volume of 690.4 m³. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), plants serving agglomerations of this size are required to provide secondary treatment, but the advanced level here indicates compliance with more stringent standards for sensitive areas. The treated effluent is discharged into the local watershed, which ultimately drains into the Seine River basin and then into the English Channel. The plant's advanced treatment helps protect downstream water quality and supports the ecological health of the Seine estuary and coastal marine environment.

The plant discharges into the Seine River basin, which flows through Normandy and into the English Channel. The Seine estuary is an ecologically important area that supports diverse aquatic life, including migratory fish species. Advanced treatment at this plant reduces nutrient loading, helping to prevent eutrophication in the downstream marine environment.