TERRASSA Wastewater Treatment Plant, Rubí, Barcelona, Spain

TERRASSA is a wastewater treatment plant located in Rubí, in the province of Barcelona, within the autonomous community of Catalunya, Spain. It serves a population equivalent of 195,573, classifying it as a large agglomeration under EU regulations. The plant is situated in the Vallès Occidental region, an area with a mix of urban and industrial activity. As a large agglomeration, TERRASSA is subject to the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment as a minimum, and tertiary treatment if the receiving waters are sensitive. The plant's designed capacity is 1. Spanish wastewater treatment plants are typically operated by municipal or regional water authorities, with permits issued by the relevant water agency. The treated effluent from TERRASSA is discharged into the local water system, which ultimately drains into the Mediterranean Sea via the Llobregat River basin. The Llobregat River is a key water resource for the Barcelona metropolitan area, supporting agriculture, industry, and drinking water supplies. The downstream environment includes coastal ecosystems that are sensitive to nutrient loading, making effective treatment essential for protecting marine water quality.

The TERRASSA plant discharges into the Llobregat River basin, which flows into the Mediterranean Sea near Barcelona. The Llobregat is a major river in Catalunya, supporting diverse aquatic life and providing water for irrigation and urban use. The coastal zone near the river mouth includes ecologically sensitive areas that rely on good water quality to sustain fisheries and recreational activities. Nutrient removal is critical to prevent eutrophication in the Mediterranean coastal waters.