Lamastre Wastewater Treatment Plant: Serving Lamastre, Auvergne-Rhône-Alpes

The Lamastre wastewater treatment plant is located in the commune of Lamastre, within the Ardèche department of the Auvergne-Rhône-Alpes region in southeastern France. The facility serves a population equivalent of approximately 10,000, placing it in the category of small to medium agglomerations under French and European regulations. As a plant operating under the EU Urban Waste Water Treatment Directive (91/271/EEC), Lamastre is required to provide at least secondary treatment for its wastewater. The directive mandates that agglomerations with a population equivalent between 2,000 and 10,000 must have collecting systems and appropriate treatment, with secondary treatment being the standard for those above 2,000 PE. The plant's discharge is regulated by French authorities under the national water law, which implements the EU directive. The treated effluent from Lamastre is discharged into the local watershed, which ultimately drains into the Rhône River via the Doux River. The Rhône is a major European river that flows into the Mediterranean Sea. The receiving water bodies support diverse aquatic life and are important for regional biodiversity, including fish species such as the European eel and various migratory fish. The plant's operation helps protect downstream water quality in this ecologically sensitive region.

The Lamastre plant discharges into the Doux River, a tributary of the Rhône River, which flows into the Mediterranean Sea. The Rhône basin supports a rich aquatic ecosystem, including migratory fish species and diverse macroinvertebrate communities. The plant's treatment helps maintain water quality in this ecologically important watershed, which is subject to seasonal variations in flow and temperature typical of Mediterranean-influenced climates.