Gelmen Wastewater Treatment Plant, Klein-Gelmen, Limburg, Belgium

Gelmen wastewater treatment plant is located in Klein-Gelmen, a village in the municipality of Heers, Limburg province, Flanders, Belgium. The plant serves a population of 4,500 and operates with advanced treatment, ensuring high-quality effluent before discharge. As an advanced treatment facility, Gelmen goes beyond secondary treatment to remove nutrients and other pollutants, meeting stringent standards under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant has a designed capacity of 5,400 m³/day and currently discharges 804.37 m³/day, indicating operational headroom. The treated effluent from Gelmen ultimately drains into the Herk River, a tributary of the Demer, which flows into the Dijle and then the Rupel, reaching the Scheldt estuary and the North Sea. This waterway supports diverse aquatic life and is part of the Scheldt basin, an ecologically important region in Belgium.

The plant's discharge enters the Herk River, a small stream that flows into the Demer River, part of the Scheldt basin. The Demer and Dijle rivers support rich biodiversity, including fish species like pike and roach, and the Scheldt estuary is a critical migratory corridor for birds. Advanced treatment helps protect these waters from nutrient pollution.