Mariestads avloppsreningsverk - Municipal Wastewater Treatment Plant in Mariestad, Sweden

Mariestads avloppsreningsverk is the municipal wastewater treatment plant serving the city of Mariestad in Vastra Gotaland County, Sweden. The facility handles wastewater from a population of around 21,713, placing it in the medium agglomeration category under Swedish and EU regulations. As a Swedish plant, it operates under the EU Urban Waste Water Treatment Directive 91/271/EEC, which requires secondary treatment for agglomerations of this size. The plant's designed capacity is 1.00 (likely in thousand cubic meters per day or similar unit), indicating its scale. The facility is expected to meet national standards for nutrient removal, particularly in sensitive areas. The plant's treated effluent ultimately reaches the Vänern basin, as Mariestad is located on the shores of Lake Vänern, Sweden's largest lake. The discharge contributes to the lake's water quality, which supports diverse aquatic life and is an important resource for recreation and drinking water. The plant's proximity to the coast (within 50 km) means its discharge may influence the broader Kattegat marine environment via the Göta älv river system.

Mariestads avloppsreningsverk discharges into the local watershed that drains into Lake Vänern, Sweden's largest lake. Lake Vänern is a major freshwater ecosystem supporting diverse fish species and migratory birds. The lake's outflow via the Göta älv river reaches the Kattegat, a marine area of ecological significance. The plant's nutrient removal performance is critical to preventing eutrophication in these downstream waters.