Wesseln Wastewater Treatment Plant, Schleswig-Holstein, Germany

The Wesseln wastewater treatment plant is located in the municipality of Wesseln, within the district of Dithmarschen in Schleswig-Holstein, Germany. It served a population of 1,379, classifying it as a small agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant is now closed. As a secondary treatment facility, it provided biological treatment to reduce organic matter and suspended solids. The designed capacity was 2,100 m³/day, with an actual discharge volume of 348.99 m³/day. For small agglomerations in Germany, secondary treatment is typically sufficient unless the receiving water is a sensitive area requiring more advanced treatment. The plant discharged treated wastewater into the North Sea coastal zone, as it lies within 10 km of the coast. The effluent likely entered local drainage channels leading to the North Sea, which supports diverse marine life and is an important area for fisheries and migratory birds. The closure of the plant suggests that wastewater from this area is now handled by a larger regional facility.

The plant discharged into the North Sea coastal waters, which are part of the Wadden Sea ecosystem, a highly productive environment supporting seals, migratory birds, and fish. The effluent entered local drainage networks that flow into the North Sea, a semi-enclosed sea with limited water exchange, making it sensitive to nutrient inputs. The region's flat terrain and agricultural land use contribute to diffuse pollution pressures.