UWWTP Vijfhuizen - Closed Advanced Wastewater Treatment Plant in Noord-Holland

UWWTP Vijfhuizen is a former wastewater treatment plant located in Vijfhuizen, a town in the Haarlemmermeer municipality of Noord-Holland, Netherlands. The plant was designed to serve the local population with a capacity of 1,350 cubic meters per day, reflecting its role in managing municipal wastewater in this region. The plant provided advanced treatment, which goes beyond secondary treatment to remove nutrients such as nitrogen and phosphorus. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), advanced treatment is required for discharges into sensitive areas, which are common in the Netherlands due to its dense water network and ecological sensitivity. The treated effluent from the plant would have been discharged into local waterways that ultimately drain into the North Sea. The Netherlands' extensive system of canals, polders, and rivers means that wastewater treatment plays a crucial role in protecting both local water quality and the downstream marine environment.

The plant's receiving waters are part of the Rhine-Meuse-Scheldt delta system, which flows into the North Sea. This region is ecologically sensitive, supporting diverse aquatic life and serving as a critical habitat for migratory fish. The advanced treatment level helps reduce nutrient loading, mitigating eutrophication risks in downstream lakes and coastal areas.