Hudiksvalls avloppsreningsverk - Hudiksvall Wastewater Treatment Plant, Sweden

Hudiksvalls avloppsreningsverk is the municipal wastewater treatment plant for the city of Hudiksvall in Gävleborg County, Sweden. The plant serves a population of approximately 36,665, classifying it as a medium-sized agglomeration under Swedish and EU regulations. Its location near the coast of the Gulf of Bothnia places it in a sensitive coastal environment. As a Swedish plant, Hudiksvalls avloppsreningsverk operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. For plants discharging into sensitive coastal areas, the directive may also mandate tertiary treatment to reduce nutrient loads. The plant's designed capacity is 1.00 (likely in thousands of cubic meters per day), indicating it is sized to handle the local population's wastewater. The treated effluent is discharged into the Gulf of Bothnia, a brackish sea that is part of the Baltic Sea ecosystem. This water body is sensitive to nutrient pollution, which can cause eutrophication and algal blooms. The plant's performance is therefore critical for protecting the coastal waters and supporting the region's aquatic life and recreational uses.

The plant discharges into the Gulf of Bothnia, a northern arm of the Baltic Sea. This brackish water body is ecologically sensitive, supporting diverse fish populations and migratory birds. Nutrient inputs from wastewater can contribute to eutrophication, affecting water quality and marine habitats. The plant's location within 50 km of the coast underscores the importance of effective treatment to protect the coastal environment.