Sant Llorenç Savall Wastewater Treatment Plant, Sant Llorenç Savall, Catalunya

The Sant Llorenç Savall wastewater treatment plant is located in Sant Llorenç Savall, a municipality in the Vallès Occidental comarca of Barcelona, Catalunya, Spain. The plant serves a population of 1,875 and is part of the region's municipal wastewater infrastructure, operating under Spain's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant provides secondary treatment, which is the standard required by the EU directive for freshwater discharges from agglomerations of this size. It has a designed capacity of 3,000 m³/day and currently treats an average daily flow of 515.90 m³/day, indicating significant spare capacity. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into the local water environment, likely a tributary of the Ripoll River, which flows into the Besòs River and ultimately reaches the Mediterranean Sea near Barcelona. The plant plays a key role in protecting the Besòs River basin and the coastal waters of the Catalan coast from pollution, supporting aquatic life and recreational uses downstream.

The plant discharges into the local watershed, which drains via the Ripoll River into the Besòs River and then into the Mediterranean Sea. The Besòs River basin is a densely populated and industrialized area, making wastewater treatment critical for water quality. The downstream environment includes ecologically sensitive coastal zones that support diverse marine life and are important for tourism and fisheries.