ARRE Wastewater Treatment Plant, Årre, Denmark

ARRE is a wastewater treatment plant located in Årre, a small town in Varde Municipality, Region of Southern Denmark. The plant serves a population of approximately 750 people, placing it in the small agglomeration category under EU regulations. The plant provides secondary treatment, which is the minimum standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for discharges to freshwater and estuaries. The designed capacity is 2,600 m³/day, with an actual discharge volume of 699.75 m³/day, indicating ample reserve capacity. Treated effluent from ARRE likely discharges into local watercourses that flow toward the North Sea, given its proximity to the coast. The plant plays a key role in protecting the coastal environment and supporting the ecological health of the Wadden Sea region, a vital area for migratory birds and marine life.

ARRE discharges treated wastewater into local streams that drain into the North Sea via the Varde River system. The plant is within 10 km of the coast, making its discharge relevant to coastal water quality. The downstream environment includes the Wadden Sea, a shallow tidal basin that supports diverse aquatic life and serves as an important migratory corridor for birds. Proper treatment helps prevent nutrient enrichment and protect this sensitive ecosystem.