GIEN Wastewater Treatment Plant, Gien, Centre-Val de Loire, France

The GIEN wastewater treatment plant is located in Gien, a commune in the Loiret department of Centre-Val de Loire, France. The facility serves a population of approximately 17,746, classifying it as a medium-sized agglomeration under EU regulations. As a French treatment plant, GIEN operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations of this size. The directive also requires appropriate treatment before discharge into freshwater bodies to protect water quality. The plant's treated effluent is discharged into the Loire River, one of France's major waterways, which flows westward through the Loire Valley to the Atlantic Ocean. The Loire Valley is ecologically significant, supporting diverse aquatic life and serving as a migratory corridor for fish species.

The GIEN plant discharges into the Loire River, which flows through the Loire Valley and ultimately reaches the Atlantic Ocean near Saint-Nazaire. The Loire is a dynamic river system with seasonal flow variations, supporting a rich biodiversity including migratory fish such as Atlantic salmon and European eel. The watershed is also important for agriculture and tourism, making effective wastewater treatment critical to maintaining water quality.