COCA Wastewater Treatment Plant, Coca, Castilla y León, Spain

COCA is a wastewater treatment plant located in Coca, a town in the province of Segovia, within the autonomous community of Castilla y León, Spain. The plant serves a population of approximately 5,000 residents and is part of the municipal wastewater infrastructure for the area. The facility operates with advanced treatment, which goes beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The designed capacity is 5,000 m³/day, and the reported discharge volume is 498.63 m³/day, indicating a utilization rate well below capacity. The treated effluent is discharged into the local watershed, which ultimately drains into the Duero River basin. The Duero River flows westward through Spain and Portugal, emptying into the Atlantic Ocean near Porto. The plant's advanced treatment helps protect the ecological quality of the receiving waters, supporting aquatic life and downstream water uses.

The plant discharges into the Duero River basin, which flows through the Castilla y León region and into Portugal. The Duero is a major river supporting diverse aquatic ecosystems and agricultural irrigation. Advanced treatment at COCA reduces nutrient loads and pollutants, helping to maintain water quality in the river and its downstream estuary, which is ecologically sensitive and supports migratory fish species.