SAINT MARCELLIN Bourg Wastewater Treatment Plant - Saint-Marcellin-en-Forez, Auvergne-Rhône-Alpes

SAINT MARCELLIN Bourg is a wastewater treatment plant located in Saint-Marcellin-en-Forez, a commune in the Loire department of Auvergne-Rhône-Alpes, France. The plant serves a population of approximately 5,697 residents, placing it in the small-to-medium agglomeration category under French and EU regulations. As a French facility, the plant operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size discharging into freshwater. The directive also mandates appropriate treatment to meet quality standards for the receiving environment. The plant's treatment process and capacity are consistent with the regulatory framework for communities of this scale. The treated effluent is discharged into the local watershed, which ultimately drains into the Loire River basin. The Loire is France's longest river and flows into the Atlantic Ocean. The plant plays a key role in protecting the water quality of the Loire and its tributaries, supporting aquatic ecosystems and downstream uses.

The plant discharges into the Loire River basin, which flows westward through central France before emptying into the Bay of Biscay (Atlantic Ocean). The Loire basin supports diverse aquatic life, including migratory fish species such as Atlantic salmon and European eel. The plant's treatment helps maintain water quality in this ecologically significant river system, which is also a source for drinking water and agriculture.