ZARZALEJO Wastewater Treatment Plant, Zarzalejo (estación), Comunidad de Madrid, Spain

ZARZALEJO is a wastewater treatment plant located in the municipality of Zarzalejo, specifically in the locality of Zarzalejo (estación), within the Comunidad de Madrid, Spain. The plant serves a small population of around 1,111 people, reflecting its role in a rural or semi-rural setting. As part of Spain's wastewater infrastructure, it contributes to the sanitation needs of this inland community. Given the small population served, the plant is classified as a small agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC). This directive requires appropriate treatment for discharges into freshwater bodies, typically secondary treatment, though specific treatment levels may vary based on local environmental sensitivity. The plant operates under Spain's national water regulations, which implement EU standards. The treated effluent from ZARZALEJO is discharged into a local watercourse that ultimately drains into the Tagus River basin, one of the Iberian Peninsula's major river systems. The Tagus River flows westward through Spain and Portugal, emptying into the Atlantic Ocean near Lisbon. The plant's operations help protect the local aquatic environment and downstream water quality.

ZARZALEJO is located inland in the Comunidad de Madrid, within the Tagus River basin. The treated wastewater discharges into a local stream that feeds into the Tagus River, which flows through central Spain and Portugal to the Atlantic Ocean. The Tagus basin supports diverse aquatic life and is an important water resource for agriculture and urban areas. The plant's treatment helps maintain water quality in this ecologically significant watershed.