Alcains Wastewater Treatment Plant, Castelo Branco | Portugal

The Alcains wastewater treatment plant is located near Castelo Branco in central Portugal, serving the town of Alcains with a population of approximately 4,600. The plant operates under Portuguese regulations that implement the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The plant provides secondary treatment, which typically involves biological processes to reduce organic matter and suspended solids. With a designed capacity of 5,708 cubic meters per day and an average daily discharge volume of 767 cubic meters, the plant operates well within its capacity, indicating adequate infrastructure for current demand. The treated effluent from Alcains is discharged into the local water system, which ultimately drains into the Tagus River basin, one of the most important river systems in the Iberian Peninsula. The Tagus River flows westward through Portugal and into the Atlantic Ocean near Lisbon, supporting diverse aquatic ecosystems and providing water for agriculture and urban use along its course.

The Alcains plant discharges into the Tagus River basin, which flows through central Portugal and empties into the Atlantic Ocean near Lisbon. The Tagus River supports a variety of fish species and provides critical habitat for migratory birds. The watershed is ecologically sensitive due to its role in regional water supply and biodiversity, and the plant's secondary treatment helps protect downstream water quality.