Ballstaverket Wastewater Treatment Plant, Tuna distrikt, Sundsvall, Sweden

Ballstaverket is a wastewater treatment plant located in Tuna distrikt, within Sundsvall municipality, Västernorrland County, Sweden. The plant serves a population of approximately 9,645 people, placing it in the medium agglomeration category under EU classification. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), Sweden requires secondary treatment for agglomerations of this size, with more stringent treatment in sensitive areas. The plant's designed capacity is 1.00 (likely in thousands of cubic meters per day), indicating it is sized to handle the local wastewater load. The plant discharges into the local watershed, which ultimately drains into the Baltic Sea via the Gulf of Bothnia. This region supports diverse aquatic life and is important for migratory fish species. The plant's operation contributes to protecting downstream water quality in this ecologically sensitive coastal environment.

Ballstaverket discharges into the local river system that flows through Sundsvall and into the Gulf of Bothnia, part of the Baltic Sea. The Baltic Sea is a brackish water body with limited water exchange, making it sensitive to nutrient pollution. The plant's treatment helps protect downstream ecosystems, including spawning grounds for salmonids and habitats for aquatic plants and invertebrates.