Illiers-Combray Wastewater Treatment Plant, Centre-Val de Loire, France

The Illiers-Combray wastewater treatment plant is located in the commune of Illiers-Combray in the Eure-et-Loir department of Centre-Val de Loire, France. It serves a population of approximately 3,925 residents, classifying it as a small agglomeration under French and EU regulations. The plant employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 5,300 m³/day and an average discharge volume of 700.21 m³/day, the facility operates well within its capacity, ensuring effective treatment of wastewater. The treated effluent is discharged into a local watercourse that ultimately drains into the Loire River basin, a major river system flowing into the Atlantic Ocean. The plant's advanced treatment helps protect the sensitive aquatic ecosystems of the Loire basin, supporting biodiversity and water quality downstream.

The plant discharges into a tributary of the Loire River, which flows through the Centre-Val de Loire region before reaching the Atlantic Ocean. The Loire basin is ecologically significant, supporting diverse fish populations and migratory species. Advanced treatment at this plant helps reduce nutrient loading and protects downstream habitats from eutrophication.