SOLLESTED Wastewater Treatment Plant, Søllested, Denmark

SOLLESTED is a wastewater treatment plant located in Søllested, a town in Lolland Municipality, Region Sjælland, Denmark. The plant serves a population of approximately 1,207 people and is part of Denmark's municipal wastewater infrastructure. It operates under Danish regulations which implement the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant provides advanced treatment, which goes beyond the secondary treatment required by the EU directive for agglomerations of this size. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive receiving waters. The plant has a designed capacity of 5,267 m³/day and currently discharges 813.17 m³/day, indicating significant spare capacity. The treated effluent is discharged into the local watershed, which ultimately drains into the Baltic Sea. The plant's location within 10 km of the coast means its discharge can affect coastal water quality. The Baltic Sea is a sensitive marine environment with eutrophication challenges, making advanced treatment crucial for reducing nutrient loads.

The plant discharges into the local watershed that flows into the Baltic Sea, a semi-enclosed sea with limited water exchange and high sensitivity to nutrient pollution. The Baltic Sea suffers from eutrophication due to excess nitrogen and phosphorus, leading to algal blooms and oxygen depletion. Advanced treatment at SOLLESTED helps reduce these nutrient inputs, supporting the ecological health of coastal waters and marine habitats.