STEP DU MOULINOT Wastewater Treatment Plant, Busy, Bourgogne-Franche-Comté

STEP DU MOULINOT is a municipal wastewater treatment plant located in Busy, a commune in the Doubs department of Bourgogne-Franche-Comté, eastern France. The plant serves a population equivalent of approximately 2,500 people, placing it in the small agglomeration category under French regulations. The facility provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for inland plants serving between 2,000 and 10,000 population equivalents. The plant has a designed capacity of 2,700 m³/day and currently treats an average daily flow of 446 m³/day, indicating significant spare capacity. The treated effluent is discharged into a local watercourse that ultimately drains into the Doubs River, a tributary of the Saône, which flows into the Rhône and eventually the Mediterranean Sea. The plant plays a key role in protecting the water quality of the Doubs basin, which supports diverse aquatic life and is used for recreation and agriculture downstream.

The plant discharges into a small stream that feeds the Doubs River, part of the Rhône-Mediterranean basin. The Doubs River flows through the Jura mountains and supports a rich ecosystem including fish species such as brown trout and grayling. Downstream, the river joins the Saône, which flows into the Rhône and reaches the Mediterranean Sea. The watershed is ecologically sensitive due to its karst geology and agricultural land use, making nutrient removal important for preventing eutrophication.