LIGNIERES DE TOURAINE La Calotte Wastewater Treatment Plant, Azay-le-Rideau, France

LIGNIERES DE TOURAINE La Calotte is an advanced wastewater treatment plant located in Azay-le-Rideau, within the Centre-Val de Loire region of France. The plant serves a population of 3,083 and is part of the municipal wastewater infrastructure for the area. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 3,200 m³/day and an actual discharge volume of 550 m³/day, the plant operates well below its capacity. 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 a higher standard, likely due to the sensitivity of the receiving environment. The treated effluent is discharged into local watercourses that ultimately drain into the Loire River basin. The Loire is one of France's major rivers, supporting diverse aquatic ecosystems and flowing into the Atlantic Ocean. The plant's advanced treatment helps protect downstream water quality and ecological health.

The plant discharges into the Loire River basin, which flows through the Centre-Val de Loire region and eventually reaches the Atlantic Ocean. The Loire is known for its rich biodiversity, including migratory fish species such as Atlantic salmon and European eel. Advanced treatment at this plant helps reduce nutrient loading, which is critical for preventing eutrophication in the river and its estuary.