LESSINES Wastewater Treatment Plant - Lessines, Hainaut, Belgium

The LESSINES wastewater treatment plant is located in Lessines, within the province of Hainaut in the Wallonia region of Belgium. It serves a population of 4,236 and has a designed capacity of 12,000 m³/day, indicating it is sized to accommodate future growth or industrial flows. The plant provides secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this scale. As a secondary treatment facility, LESSINES uses biological processes to remove organic matter and suspended solids from wastewater. The plant discharges treated effluent at a volume of 757.18 m³/day, well below its designed capacity. Under the EU UWWTD, secondary treatment is mandatory for inland plants serving populations over 2,000, and Belgium has implemented this directive through regional regulations in Wallonia. The treated effluent from LESSINES is discharged into local waterways that ultimately drain into the Scheldt River basin. The Scheldt flows through Belgium and the Netherlands before reaching the North Sea. The plant plays a key role in protecting the water quality of the Dendre River, a tributary of the Scheldt, and the downstream aquatic ecosystems. By reducing organic pollution and nutrients, the plant helps prevent eutrophication and supports biodiversity in the region's rivers and estuaries.

The LESSINES plant discharges into the Dendre River, a tributary of the Scheldt River basin. The Scheldt flows through Belgium and the Netherlands into the North Sea. This watershed supports diverse aquatic life and is an important ecological corridor for migratory fish. The plant's secondary treatment reduces organic load and suspended solids, helping to maintain water quality in the Dendre and downstream Scheldt estuary, which is ecologically sensitive due to its tidal dynamics and nutrient inputs.