Milharado Wastewater Treatment Plant, Mafra, Portugal

Milharado is a wastewater treatment plant located in Casal dos Pedregulhos, Milharado, in the municipality of Mafra, Lisbon District, Portugal. The plant serves a population of approximately 3,400 and is situated in a peri-urban area near the Atlantic coast. 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. With a designed capacity of 3,413 m³/day and a current discharge volume of 566.88 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into the local watershed, which ultimately drains to the Atlantic Ocean. The proximity to the coast (within 10 km) means the plant's discharge can influence coastal water quality, making effective treatment essential for protecting marine ecosystems and recreational waters.

The plant discharges into a small stream that flows into the Atlantic Ocean near the Lisbon coast. The receiving waters support diverse marine life and are used for recreation and fishing. The coastal area is ecologically sensitive, with habitats that depend on good water quality to sustain biodiversity and prevent eutrophication.