ORNANS Wastewater Treatment Plant, Ornans, Bourgogne-Franche-Comté, France

The ORNANS wastewater treatment plant is located in Ornans, a commune in the Doubs department of Bourgogne-Franche-Comté, France. It serves a population of approximately 4,600 residents, classifying it as a small agglomeration under French and EU regulations. The plant is situated inland, away from coastal areas, and its operations are part of the regional water management infrastructure. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 4,500 m³/day and an actual discharge volume of 820.63 m³/day, the facility operates well below its capacity, indicating room for future growth or seasonal variations. The plant is subject to French national regulations that implement the EU directive, ensuring compliance with stringent effluent quality standards. The treated wastewater from ORNANS is discharged into the local watershed, which ultimately drains into the Loue River, a tributary of the Doubs River. The Doubs River flows through the Jura region and eventually joins the Saône, a major river in eastern France that feeds into the Rhône. This watercourse supports diverse aquatic life and is important for regional biodiversity, making the plant's advanced treatment crucial for protecting downstream ecosystems.

The ORNANS plant discharges into the Loue River basin, which flows into the Doubs River, a key tributary of the Saône. The Saône joins the Rhône, which empties into the Mediterranean Sea. The watershed supports sensitive aquatic habitats, including fish spawning grounds and diverse macroinvertebrate communities. Advanced treatment helps minimize nutrient and pollutant loads, protecting the ecological integrity of these downstream water bodies.