WATTEN SE Wastewater Treatment Plant, Holque, Hauts-de-France

WATTEN SE is a wastewater treatment plant located in Holque, within the Hauts-de-France region of northern France. The facility serves a population of approximately 4,540 people and is part of the municipal infrastructure for the Dunkerque area. It operates under the French regulatory framework, which implements the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant provides advanced treatment, which goes beyond the secondary treatment required by the EU directive for agglomerations of this size. With a designed capacity of 4,500 m³/day and an average daily discharge of 809.93 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into local watercourses that ultimately drain into the North Sea. The plant plays a key role in protecting the regional aquatic environment, including the nearby wetlands and the coastal waters of the English Channel. Its advanced treatment ensures high-quality effluent, reducing nutrient loads and safeguarding downstream ecosystems.

The plant discharges into the local drainage network, which flows into the Aa River and then into the North Sea near Dunkerque. This coastal region includes ecologically sensitive areas such as the Platier d'Oye nature reserve, which supports diverse birdlife and aquatic habitats. The advanced treatment helps minimize eutrophication risks in the downstream marine environment.