Santa Barbara Wastewater Treatment Plant, Santa Bàrbara, Catalunya, Spain

The Santa Barbara wastewater treatment plant is located in Santa Bàrbara, a municipality in the Montsià comarca of Tarragona, Catalunya, Spain. It serves a population of 4,086 people, making it a small agglomeration under EU classification. The plant is situated inland, approximately 50 km from the Mediterranean coast. 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. Its designed capacity is 5,200 m³/day, and it currently treats an average daily flow of 532.10 m³/day, indicating significant spare capacity. Secondary treatment typically involves biological processes such as activated sludge or trickling filters. The treated effluent is discharged into a local watercourse that ultimately drains into the Mediterranean Sea. The plant plays a key role in protecting the Ebro Delta region, a ecologically sensitive area known for its wetlands and biodiversity. By removing organic matter and nutrients, the plant helps prevent eutrophication and maintains water quality in downstream rivers and coastal waters.

The plant discharges into a local stream that flows into the Ebro River basin, which empties into the Mediterranean Sea near the Ebro Delta. The delta is a critical habitat for migratory birds and supports diverse aquatic life. The plant's secondary treatment reduces organic load and nutrients, helping to protect the delta's sensitive ecosystems from eutrophication and pollution.