Caria Wastewater Treatment Plant, Belmonte, Portugal

Caria wastewater treatment plant is located in the parish of Caria, within the municipality of Belmonte, in the Castelo Branco district of central Portugal. The facility serves a population of approximately 2,600 residents, providing secondary treatment to municipal wastewater. As a small-scale plant, it plays a key role in managing local sanitation needs. The plant operates under Portugal's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. With a designed capacity of 2,778 m³/day and an actual discharge volume of 433.5 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. Treated effluent from the plant is discharged into the local water system, which ultimately drains into the Zêzere River, a major tributary of the Tagus River. The Tagus flows westward through Portugal to the Atlantic Ocean near Lisbon. The plant's operations help protect downstream water quality in this ecologically important river basin.

The Caria plant discharges into the Zêzere River basin, which feeds into the Tagus River, one of the longest rivers in the Iberian Peninsula. The Tagus estuary near Lisbon supports diverse aquatic life and is an important migratory corridor for fish and birds. Secondary treatment reduces organic pollutants and suspended solids, helping to maintain water quality in this sensitive watershed.