Ribeira de Moinhos Poiares Wastewater Treatment Plant, Vila Nova de Poiares, Portugal

Ribeira de Moinhos Poiares is a municipal wastewater treatment plant located in Vila Nova de Poiares, Coimbra District, Portugal. The facility serves a population of approximately 4,000 residents, reflecting its role in managing domestic wastewater for this inland community. The plant is situated in the central region of Portugal, an area characterized by rolling hills and river valleys. The plant provides secondary treatment, which is the standard biological treatment stage required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 6,500 m³/day and an average discharge volume of 666.92 m³/day, the plant operates well below its capacity, indicating room for future growth. The treatment process removes organic matter and suspended solids before discharge. Treated effluent from the plant is discharged into a local watercourse, which ultimately drains into the Mondego River basin. The Mondego River is the longest river entirely within Portugal and flows into the Atlantic Ocean near Figueira da Foz. The plant plays a key role in protecting the water quality of this river system, which supports diverse aquatic life and is used for agriculture and recreation downstream.

The plant discharges into a tributary of the Mondego River, which flows westward through central Portugal to the Atlantic Ocean. The Mondego basin supports important ecosystems, including riparian forests and wetlands that provide habitat for fish, birds, and amphibians. Downstream waters are used for irrigation and fishing, making nutrient and pathogen removal from wastewater critical to maintaining ecological balance.