Colbe _ Burgeln Wastewater Treatment Plant, Bürgeln, Hessen, Germany

Colbe _ Burgeln is an advanced wastewater treatment plant located in Bürgeln, a district of Cölbe in the Landkreis Marburg-Biedenkopf, Hessen, Germany. The plant serves a population of approximately 3,200 and has a designed capacity of 3,200 m³/day, with an average discharge volume of 596.15 m³/day. As an advanced treatment facility, the plant goes beyond secondary treatment to remove nutrients such as nitrogen and phosphorus, which is typical for plants in sensitive catchment areas under the EU Urban Waste Water Treatment Directive (91/271/EEC). Germany implements this directive through national legislation, requiring advanced treatment for agglomerations above 10,000 PE in sensitive areas; however, smaller plants like this one may also adopt advanced treatment to protect local water quality. The treated effluent is discharged into the local watershed, which ultimately drains into the Lahn River and then the Rhine River, flowing into the North Sea. The plant plays a key role in protecting the Lahn-Rhine system from nutrient pollution, supporting aquatic life and downstream ecosystems.

The plant discharges into the Lahn River basin, a tributary of the Rhine River, which flows through central Germany before reaching the North Sea. The Lahn is an ecologically sensitive waterway that supports diverse fish populations and serves as a migratory corridor for species such as salmon and eel. Advanced treatment at this plant helps reduce nutrient loads, mitigating eutrophication risks in the Rhine and North Sea.