San Martín de Trevejo Wastewater Treatment Plant, Cáceres, Extremadura

The San Martín de Trevejo wastewater treatment plant is located in the municipality of San Martín de Trevejo, in the province of Cáceres, Extremadura, Spain. It serves a population of approximately 2,200 residents, classifying it as a small agglomeration under EU regulations. The plant is situated inland, away from coastal areas, and its operations are part of the regional water management infrastructure. The plant provides secondary treatment, which is the minimum standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. The plant has a designed capacity of 2,200 m³/day and treats an average daily flow of 398.74 m³/day, indicating it operates well below its capacity. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into the local watershed, which ultimately drains into the Tagus River basin, one of the most important river systems in the Iberian Peninsula. The Tagus River flows westward through Spain and Portugal, emptying into the Atlantic Ocean near Lisbon. The plant's operations help protect the water quality of local streams and the downstream river ecosystem, supporting aquatic life and agricultural water use.

The plant discharges into the Tagus River basin, which flows through central Spain and Portugal to the Atlantic Ocean. The watershed supports diverse aquatic habitats and is an important resource for irrigation and drinking water. The region's Mediterranean climate with seasonal rainfall means that maintaining water quality is crucial for both ecological health and human use.