OBJAT SIER Objat St Aulaire Wastewater Treatment Plant, Allassac, France

OBJAT SIER Objat St Aulaire is a municipal wastewater treatment plant located in Allassac, within the Corrèze department of Nouvelle-Aquitaine, France. The plant serves a population of approximately 4,740 and has a designed capacity of 6,000 cubic meters per day, with an average discharge volume of 845.61 m³/day. The plant provides secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. Secondary treatment typically involves biological oxidation and sedimentation to reduce organic matter and suspended solids before discharge. The treated effluent is discharged into local waterways that ultimately drain into the Vézère River, a tributary of the Dordogne River, which flows into the Atlantic Ocean via the Gironde estuary. The plant plays a key role in protecting the water quality of the Vézère watershed, which supports diverse aquatic life and is important for regional biodiversity.

The plant discharges into the Vézère River basin, which flows through the Corrèze region and joins the Dordogne River. The Dordogne is a major river in southwestern France, known for its rich aquatic ecosystems and migratory fish species such as salmon and eels. The watershed supports diverse habitats and is ecologically sensitive, requiring effective wastewater treatment to prevent nutrient enrichment and maintain water quality.