ALARAZ Wastewater Treatment Plant, Alaraz, Castilla y León, Spain

ALARAZ is a wastewater treatment plant located in the municipality of Alaraz, in the province of Salamanca, Castilla y León, Spain. The plant serves a population of around 3,975, making it a small agglomeration under EU classification. It is situated inland, away from coastal areas, and treats wastewater from the local community. The plant employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 3,975 m³/day and a discharge volume of 300 m³/day, the plant operates well within its capacity. The advanced treatment ensures high-quality effluent, reducing nutrients and pollutants before discharge. The treated effluent is released into local water bodies that drain into the Duero River basin, ultimately reaching the Atlantic Ocean. The plant plays a key role in protecting the region's water quality, supporting aquatic life in the Duero watershed, and contributing to the ecological health of downstream environments.

The plant discharges into local streams that are part of the Duero River basin, one of the major river systems in the Iberian Peninsula. The Duero flows westward through Spain and Portugal, emptying into the Atlantic Ocean near Porto. The watershed supports diverse aquatic ecosystems and is important for agriculture and biodiversity in the region. Advanced treatment helps minimize nutrient loading and protects downstream water quality.