OVER JERSTAL Wastewater Treatment Plant, Over Jerstal, Denmark

OVER JERSTAL is a wastewater treatment plant located in Over Jerstal, a town in Haderslev Municipality, Denmark. The plant serves a population of approximately 1,202 people, placing it in the small agglomeration category under Danish and EU regulations. It is situated near Gelsåvej and operates within the Danish wastewater management framework. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for discharges into freshwater and estuaries from agglomerations of this size. The designed capacity is 2,100 m³/day, and the current discharge volume is 203.42 m³/day, indicating operational headroom. The plant is owned and operated by the local municipality, consistent with Danish practice where municipal utilities manage wastewater infrastructure. Treated effluent from OVER JERSTAL is discharged into the local water system, which ultimately drains into the North Sea via the Gelså River and the Wadden Sea. The Wadden Sea is an ecologically sensitive intertidal zone that supports diverse bird, fish, and marine life. The plant's secondary treatment helps protect this downstream environment by reducing organic load and nutrients.

OVER JERSTAL discharges treated wastewater into the Gelså River, which flows through southern Jutland and empties into the Wadden Sea, a shallow coastal sea along the Danish and German North Sea coast. The Wadden Sea is a critical habitat for migratory birds, seals, and fish, and its ecological health depends on controlling nutrient inputs. The plant's secondary treatment reduces organic matter and nutrients, helping to prevent eutrophication in this sensitive marine environment.