Carregueira_Pinheiro Grande Wastewater Treatment Plant, Chamusca, Portugal

Carregueira_Pinheiro Grande is a wastewater treatment plant located in the parish of Pinheiro Grande, within the municipality of Chamusca, in the Santarém district of Portugal. The plant serves a population of approximately 4,400 people, placing it in the small agglomeration category under Portuguese and EU regulations. The plant provides secondary treatment, which is the standard level required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. With a designed capacity of 7,178 m³/day and an average daily flow of 733.61 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into local watercourses that drain into the Tagus River basin, one of the most important river systems in the Iberian Peninsula. The Tagus River flows westward through Portugal to the Atlantic Ocean near Lisbon, supporting diverse aquatic ecosystems and providing water for agriculture and urban use downstream.

The plant discharges into the Tagus River basin, which ultimately flows into the Atlantic Ocean near Lisbon. The Tagus River supports a variety of fish species and provides critical habitat for migratory birds. Downstream waters are used for irrigation and drinking water supply, making the plant's secondary treatment essential for protecting water quality and ecological health in the region.