TRETS Wastewater Treatment Plant, Trets, Provence-Alpes-Côte d'Azur, France

TRETS is a municipal wastewater treatment plant located in Trets, a commune in the Bouches-du-Rhône department of Provence-Alpes-Côte d'Azur, France. The plant serves a population of approximately 34,048, classifying it as a medium agglomeration under EU regulations. It is situated inland, more than 50 km from the coast, and its operations are part of the regional water management infrastructure. As a French wastewater facility, TRETS operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations with a population equivalent (PE) between 10,000 and 150,000. The plant's designed capacity is 1.00 (likely in thousands of cubic meters per day or similar unit), indicating it is sized to handle the local wastewater load. Compliance with national regulations is overseen by the French water agencies and local authorities. The treated effluent from TRETS is discharged into the local watershed, which ultimately drains into the Mediterranean Sea via the Arc River and the Étang de Berre lagoon. This region is ecologically significant, supporting diverse aquatic life and serving as an important migratory corridor for birds. The plant's performance is critical to protecting downstream water quality and the sensitive coastal ecosystems of the Mediterranean.

TRETS discharges into the Arc River basin, which flows into the Étang de Berre, a large lagoon connected to the Mediterranean Sea. This watershed supports diverse aquatic habitats and is an important area for migratory birds and fish species. The plant's treatment performance directly affects the ecological health of these downstream water bodies, which are subject to nutrient enrichment and pollution pressures from urban and agricultural runoff.