Alhadas Wastewater Treatment Plant, Figueira da Foz, Portugal

Alhadas wastewater treatment plant is located in the Alhadas parish of Figueira da Foz, in the Coimbra district of Portugal. The plant serves a population of approximately 2,200 people, making it a small-scale municipal facility. It is situated inland, about 10-50 km from the Atlantic coast. The plant operates with secondary treatment, which is the standard level required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The directive mandates secondary treatment for all discharges from agglomerations with a population equivalent (PE) between 2,000 and 10,000, unless the receiving waters are designated as sensitive areas requiring more stringent treatment. The plant's designed capacity is 2,200 m³/day, matching the population served. Treated wastewater from Alhadas is discharged into the local water system, which ultimately drains into the Atlantic Ocean via the Mondego River or smaller coastal streams. The region's watershed supports diverse aquatic life and is important for local agriculture and tourism. Proper treatment helps protect downstream water quality and the coastal environment.

Alhadas is located within the Mondego River basin, which flows into the Atlantic Ocean near Figueira da Foz. The downstream environment includes estuarine and coastal habitats that support fish, birds, and other wildlife. The area is ecologically sensitive due to its proximity to the coast and the importance of the Mondego estuary for migratory species. Effective wastewater treatment is crucial to prevent nutrient enrichment and maintain water quality in this dynamic coastal zone.