ORBE Wastewater Treatment Plant, Orbe, Vaud, Switzerland

The ORBE wastewater treatment plant is located in Orbe, in the canton of Vaud, Switzerland. It serves a population equivalent of approximately 15,915, classifying it as a medium-sized agglomeration under Swiss water protection standards. Switzerland's water protection legislation, particularly the Waters Protection Act (GSchG) and its ordinance (GSchV), mandates that wastewater treatment plants of this scale provide appropriate treatment to protect receiving waters. Swiss regulations typically require mechanical-biological treatment with nutrient removal for plants serving over 10,000 people, especially in sensitive catchment areas. The plant discharges into the local watershed, which ultimately drains into the Orbe River, a tributary of the Thielle River, and then into the Aare River, a major tributary of the Rhine. The Rhine flows through Germany and the Netherlands before reaching the North Sea. The region's aquatic ecosystems support diverse species, and the plant plays a key role in maintaining water quality in this ecologically sensitive area.

The ORBE plant discharges into the Orbe River, which flows into the Thielle River, then the Aare River, and eventually the Rhine River, which empties into the North Sea. The watershed supports diverse aquatic life, including fish species such as brown trout and grayling, and is an important corridor for migratory birds. The plant's operations help protect downstream ecosystems from nutrient pollution and organic load.