MOCKFJARDS ARV - Advanced Wastewater Treatment in Mockfjärd, Dalarna

MOCKFJARDS ARV is an advanced wastewater treatment plant located in Mockfjärd, within Gagnefs kommun, Dalarnas län, Sweden. The plant serves a population of 1,391, placing it in the small agglomeration category under Swedish and EU regulations. As an advanced treatment facility, MOCKFJARDS ARV goes beyond secondary treatment to remove nutrients such as nitrogen and phosphorus, which is typical for plants discharging into sensitive inland waters. The plant has a designed capacity of 3,000 m³/day and currently treats 218.36 m³/day, indicating ample reserve capacity. It operates under Sweden's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates appropriate treatment levels based on receiving water sensitivity. The plant's treated effluent is discharged into local waterways that ultimately drain into the Dalälven river basin, which flows into the Baltic Sea. The Dalälven is an ecologically significant river supporting diverse aquatic life and serving as a migratory corridor for fish. Advanced treatment helps protect downstream water quality and the sensitive Baltic Sea ecosystem.

MOCKFJARDS ARV discharges into the Dalälven river basin, which flows through Dalarna and Gävleborg counties before reaching the Baltic Sea. The Dalälven is one of Sweden's major rivers, supporting diverse fish populations including salmon and trout, and its estuary is an important habitat for migratory birds. Advanced treatment at the plant reduces nutrient loading, helping to prevent eutrophication in the Baltic Sea, a semi-enclosed sea sensitive to nitrogen and phosphorus inputs.