Ameira Wastewater Treatment Plant, Grândola, Portugal

Ameira is a wastewater treatment plant located in the Casa Branca area, serving the municipality of Grândola in the Setúbal district of Portugal. The plant provides secondary treatment for a population of approximately 4,500 residents, with a designed capacity of 7,000 m³/day and an average discharge volume of 750.29 m³/day. As a secondary treatment facility, Ameira meets the requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations with a population equivalent (PE) between 2,000 and 10,000. The plant's capacity utilization is around 10.7%, indicating significant spare capacity for future growth or seasonal variations. The treated effluent from Ameira is discharged into the local watershed, which ultimately drains into the Atlantic Ocean via the Sado River basin. The Sado estuary is an ecologically important area, supporting diverse aquatic life and serving as a habitat for migratory birds. The plant's inland location (more than 10 km from the coast) reduces direct marine impact, but its discharge contributes to the overall water quality in the Sado River system.

Ameira discharges treated wastewater into the Sado River basin, which flows into the Sado estuary and then into the Atlantic Ocean near Setúbal. The Sado estuary is a vital ecosystem supporting diverse aquatic species, including fish, crustaceans, and migratory birds. The plant's secondary treatment helps protect this sensitive environment by reducing organic pollutants and suspended solids before discharge.