Pont-sur-Yonne Wastewater Treatment Plant | Advanced Treatment, Yonne River Discharge

The Pont-sur-Yonne wastewater treatment plant is located in Pont-sur-Yonne, a commune in the Yonne department of Bourgogne-Franche-Comté, France. It serves a population of 2,379 and operates with advanced treatment processes, ensuring high-quality effluent before discharge. The plant has a designed capacity of 4,200 m³/day and currently treats 424.41 m³/day, indicating ample reserve capacity. As a French facility, it operates under the national transposition of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations of this size, but the plant exceeds requirements with advanced treatment. The treated wastewater is discharged into the Yonne River, a tributary of the Seine, which flows through the Paris Basin before reaching the English Channel. The plant plays a key role in protecting the Seine watershed and downstream aquatic ecosystems from nutrient pollution and pathogens.

The plant discharges into the Yonne River, which joins the Seine River near Montereau-Fault-Yonne. The Seine flows through Paris and eventually into the English Channel via the Seine estuary. The watershed supports diverse aquatic life and is an important ecological corridor for migratory fish species. Advanced treatment helps reduce nutrient loads, protecting downstream water quality and preventing eutrophication in the estuary.