LE BOURG D OISANS _ AQUAVALLEES Wastewater Treatment Plant, Le Bourg-d'Oisans, France

LE BOURG D OISANS _ AQUAVALLEES is a wastewater treatment plant located in Le Bourg-d'Oisans, within the Isère department of the Auvergne-Rhône-Alpes region in southeastern France. The plant serves a population equivalent of approximately 54,050, classifying it as a medium-to-large agglomeration under European Union regulations. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), agglomerations of this size are required to provide secondary treatment as a minimum, with tertiary treatment mandated if the receiving waters are designated as sensitive areas. It operates within France's national regulatory framework, which implements the directive through the French Water Law and local water agency permits. The plant discharges treated effluent into the local watershed, which ultimately drains into the Romanche River, a tributary of the Drac River, then into the Isère River, and finally into the Rhône River, which flows into the Mediterranean Sea. This river system supports diverse aquatic life and is important for regional water resources.

The plant's treated effluent enters the Romanche River, a tributary of the Drac River, which flows into the Isère River and then the Rhône River, eventually reaching the Mediterranean Sea. The watershed supports diverse aquatic ecosystems, including fish species such as brown trout and grayling, and is an important corridor for migratory birds. The region's alpine terrain influences water flow and quality, with seasonal variations from snowmelt and rainfall.