Marstrands avr verk - Advanced Wastewater Treatment Plant in Marstrand, Sweden

Marstrands avr verk is a wastewater treatment facility located in Marstrand, a coastal town in Kungälv Municipality, Västra Götaland County, Sweden. The plant serves a population of approximately 3,749 and has a design capacity of 6,000 m³/day, with an average discharge volume of 588.52 m³/day. The plant employs advanced treatment processes, which go beyond the secondary treatment standards required under the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations of this size (under 10,000 population equivalent), the directive mandates secondary treatment, but Sweden often implements higher standards, especially in sensitive coastal areas. The treated effluent is discharged into the surrounding marine environment, as the plant is located within 10 km of the coast. This discharge contributes to the water quality of the Kattegat, a part of the North Sea, which supports diverse marine life and is an important area for fisheries and recreation.

The plant discharges into the coastal waters near Marstrand, which are part of the Kattegat sea area. This region is ecologically sensitive, supporting diverse marine habitats and species. The Kattegat connects to the North Sea and ultimately the Atlantic Ocean, making proper wastewater treatment critical to prevent nutrient enrichment and protect marine biodiversity.