ZARRA Wastewater Treatment Plant, Zarra, Comunitat Valenciana, Spain

The ZARRA wastewater treatment plant is located in the municipality of Zarra, within the El Valle de Cofrentes-Ayora comarca of Comunitat Valenciana, Spain. This facility serves a small population of 594 residents, reflecting the rural character of the area. The plant is situated inland, far from the coast, and operates as part of the regional wastewater infrastructure managed by the Valencian government. As a secondary treatment plant, ZARRA meets the standard requirements under Spanish and EU regulations for small agglomerations. The EU Urban Waste Water Treatment Directive (91/271/EEC) mandates secondary treatment for all discharges from agglomerations of this size, ensuring that organic matter and suspended solids are effectively removed before discharge. The plant has a designed capacity of 2,291 cubic meters per day, with a current discharge volume of approximately 66 cubic meters per day, indicating ample capacity for future growth. The treated effluent from ZARRA is discharged into the local water system, which ultimately drains into the Júcar River basin. The Júcar River flows eastward through the Valencian region, supporting agricultural irrigation and eventually reaching the Mediterranean Sea. The plant's operation helps protect downstream water quality, particularly in the Júcar River and its tributaries, which are important for both ecological health and human use.

The ZARRA plant discharges into the Júcar River basin, which flows through the Comunitat Valenciana and empties into the Mediterranean Sea. The Júcar River supports diverse aquatic life and provides water for agriculture and drinking water downstream. The plant's secondary treatment reduces organic pollution, helping to maintain the ecological balance of the river and its associated wetlands, which are important habitats for migratory birds and native species.