Casa Branca_Cano Wastewater Treatment Plant, Sousel, Portugal

Casa Branca_Cano is a wastewater treatment plant located in Casa Branca, Sousel, in the Portalegre district of Portugal. The plant serves a population of around 3,100 people, placing it in the small agglomeration category under Portuguese and EU regulations. It is situated inland, away from coastal areas, and its operations are part of the regional sanitation infrastructure managed by local authorities. The plant provides 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. The designed capacity is 3,313 m³ per day, and the current discharge volume is 516.87 m³ per day, indicating operational headroom. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. Treated effluent is discharged into the local watershed, which ultimately drains into the Tagus River basin, one of the major river systems in the Iberian Peninsula. The Tagus flows westward through Portugal and into the Atlantic Ocean near Lisbon. The plant's operations help protect downstream water quality in the Tagus estuary, which supports diverse aquatic life and is an important ecological and economic resource for the region.

The plant discharges into the local watershed that feeds into the Tagus River basin. The Tagus River flows through central Portugal and empties into the Atlantic Ocean at the Tagus Estuary, a large and ecologically significant area. The estuary supports diverse bird populations, fish species, and habitats, making it important for both biodiversity and local fisheries. The plant's secondary treatment helps reduce nutrient and organic loads, contributing to the health of this downstream ecosystem.