HOTONNES Chef lieu Wastewater Treatment Plant, Haut Valromey, France

HOTONNES Chef lieu is a municipal wastewater treatment plant located in the village of Hotonnes, part of the commune Haut Valromey in the Ain department of Auvergne-Rhône-Alpes, France. The plant serves a population of 4,550 and operates under the French regulatory framework implementing the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant provides secondary treatment, which is the standard required by the EU directive for agglomerations of this size (between 2,000 and 10,000 population equivalent) discharging into freshwater. With a designed capacity of 2,300 m³/day and an actual discharge volume of 811.71 m³/day, the plant operates well within its capacity, indicating efficient management. The treated effluent is discharged into the local watershed, which ultimately drains into the Rhône River basin. The Rhône is one of Europe's major rivers, flowing into the Mediterranean Sea. The plant's secondary treatment helps protect downstream aquatic ecosystems and supports water quality in the region.

The plant discharges into the local watercourse, part of the Rhône River basin. The Rhône flows through southeastern France and into the Mediterranean Sea, supporting diverse aquatic life and providing water for agriculture and urban use. The watershed includes sensitive habitats that benefit from the plant's secondary treatment, which reduces organic pollutants and protects downstream water quality.