Sandillon Wastewater Treatment Plant, Centre-Val de Loire, France

The Sandillon wastewater treatment plant is located in the commune of Sandillon, within the Loiret department of the Centre-Val de Loire region in north-central France. It serves a population of approximately 4,316 residents, classifying it as a small agglomeration under French and EU regulations. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a design capacity of 8,800 m³/day and an average daily discharge volume of 770 m³/day, the facility operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into the local watershed, which ultimately drains into the Loire River, one of France's longest rivers. The Loire River flows westward through the Loire Valley, a UNESCO World Heritage site, before emptying into the Atlantic Ocean. The plant's advanced treatment helps protect the sensitive aquatic ecosystems of the Loire basin.

The Sandillon plant discharges into the Loire River basin, which flows through the Loire Valley to the Atlantic Ocean. The Loire is known for its diverse fish populations, including Atlantic salmon and European eel, and supports extensive riparian habitats. Advanced treatment at this plant reduces nutrient loads, helping to prevent eutrophication in downstream waters.