Crépy-en-Valois Wastewater Treatment Plant, Hauts-de-France, France

The Crépy-en-Valois wastewater treatment plant is located in the Oise department of Hauts-de-France, France, serving the commune of Crépy-en-Valois and surrounding areas. With a population equivalent of approximately 17,143, the facility is classified as a medium agglomeration under French and EU regulations. As a French wastewater facility, the plant operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The directive also mandates more stringent treatment if the receiving waters are designated as sensitive areas. The treated effluent is discharged into the local water system, which ultimately drains into the Oise River, a major tributary of the Seine. The Seine basin supports diverse aquatic life and provides water for agriculture, industry, and recreation downstream. Proper treatment at Crépy-en-Valois helps protect the ecological health of the Oise and Seine rivers.

The plant discharges into the Oise River basin, which flows into the Seine River and eventually reaches the English Channel. The Seine watershed is ecologically significant, supporting fish species such as Atlantic salmon and European eel, and providing habitat for migratory birds. The region's water quality is monitored under the EU Water Framework Directive to maintain ecological and chemical standards.