QUATRETONDA Wastewater Treatment Plant, Quatretonda, Valencia, Spain

The QUATRETONDA wastewater treatment plant is located in Quatretonda, a municipality in the Vall d'Albaida region of Valencia, Spain. It serves a population of approximately 2,540 residents, classifying it as a small agglomeration under Spanish and EU regulations. The plant is situated inland, more than 10 km from the coast, and discharges treated wastewater into local watercourses. The plant operates with secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. Its designed capacity is 2,916 m³/day, and the reported discharge volume is 392.15 m³/day, indicating that the plant is operating well below its capacity. As a Spanish facility, it is subject to national water quality regulations and must comply with discharge limits set by the relevant basin authority. The treated effluent from QUATRETONDA likely discharges into a tributary of the Serpis River or the Albaida River, which flow into the Mediterranean Sea via the Gulf of Valencia. The plant plays a key role in protecting local water quality and the downstream aquatic ecosystem, which supports diverse species and is used for irrigation and recreation.

The plant discharges into the local river network, which drains into the Serpis River basin and ultimately reaches the Mediterranean Sea near Gandia. This coastal area supports important marine habitats and fisheries. The plant's secondary treatment helps reduce organic pollution and nutrient loads, protecting downstream water quality and aquatic life in the river and coastal zone.