Idanha a Nova Norte Wastewater Treatment Plant, Idanha-a-Nova, Portugal

Idanha a Nova Norte is a wastewater treatment plant located in Idanha-a-Nova, in the Castelo Branco district of central Portugal. The plant serves a population of approximately 5,000 residents, classifying it as a small agglomeration under EU regulations. It is situated inland, away from coastal areas, and treats municipal wastewater from the local community. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size discharging into freshwater. The designed capacity is 5,000 m³/day, and the current discharge volume is 833.65 m³/day, indicating operational capacity well within design limits. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into a local watercourse, likely a tributary of the Tagus River basin, which flows westward through Portugal to the Atlantic Ocean near Lisbon. The plant plays a key role in protecting the local watershed from nutrient pollution and supporting downstream aquatic ecosystems.

The plant discharges into a freshwater system within the Tagus River basin, which drains into the Atlantic Ocean. The Tagus is one of the longest rivers in the Iberian Peninsula and supports diverse aquatic life, including migratory fish species. The region's Mediterranean climate with seasonal rainfall means that maintaining water quality is important for both ecological health and downstream water uses.