SASTAGO Wastewater Treatment Plant, Sástago, Aragón, Spain

The SASTAGO wastewater treatment plant is located in Sástago, a municipality in the Ribera Baja del Ebro comarca of Zaragoza, Aragón, Spain. The plant serves a population of approximately 2,309 residents and operates with secondary treatment, which is the standard level required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. As a secondary treatment facility, SASTAGO employs biological processes to reduce organic matter and suspended solids, meeting the effluent quality standards set by Spanish regulations. The plant has a designed capacity of 2,700 m³/day and currently discharges 418.50 m³/day of treated wastewater, indicating it operates well below its maximum capacity. The treated effluent is discharged into the local environment, ultimately reaching the Ebro River basin. The Ebro River is one of Spain's major watercourses, flowing into the Mediterranean Sea via the Ebro Delta, a region of significant ecological importance. The plant's operation helps protect downstream water quality and supports the ecological health of the Ebro River system.

The SASTAGO plant discharges treated wastewater into the Ebro River basin, which drains into the Mediterranean Sea through the Ebro Delta. The delta is a vital wetland ecosystem that supports diverse aquatic life and migratory birds. Secondary treatment reduces organic pollutants and suspended solids, helping to maintain water quality in the river and minimize nutrient loading that could affect the delta's sensitive habitats.