LILLOIS Wastewater Treatment Plant, Braine-l'Alleud, Belgium

The LILLOIS wastewater treatment plant is located in Braine-l'Alleud, within the Brabant wallon province of Belgium. It serves a small population of 280 residents, reflecting its role as a local facility for a rural or suburban community. The plant is situated in the Walloon region, which follows Belgian and European wastewater regulations. 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 size. It has a designed capacity of 720 m³/day and currently discharges 50.05 m³/day of treated effluent. As a small-scale facility, it contributes to protecting local water quality by reducing organic pollutants and nutrients before discharge. The treated effluent is released into the local watershed, which ultimately drains into the Senne River basin and then into the Scheldt River, flowing toward the North Sea. This connection to the Scheldt estuary underscores the plant's role in safeguarding downstream aquatic ecosystems and coastal waters from nutrient pollution.

The plant discharges into the Senne River basin, part of the Scheldt River system that flows through Belgium and the Netherlands into the North Sea. The Scheldt estuary is a vital ecological corridor for migratory fish and supports diverse aquatic life. Secondary treatment helps reduce organic load and nutrients, mitigating eutrophication risks in downstream waters.