Impianto C da Fana Avanella Wastewater Treatment Plant, Calcarelli, Sicily

Impianto C da Fana Avanella is a municipal wastewater treatment plant located in Calcarelli, a frazione of Castellana Sicula in the province of Palermo, Sicily, Italy. The plant serves a population of approximately 5,000 people, classifying it as a small agglomeration under Italian and EU regulations. The plant provides secondary treatment, which is the minimum standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. The designed capacity is 5,000 m³/day, with an average discharge volume of 989.82 m³/day, indicating a utilization rate well below capacity. The treated effluent is discharged into local watercourses that drain into the Mediterranean Sea. The plant plays a key role in protecting the region's water quality, particularly given Sicily's Mediterranean climate and the ecological sensitivity of coastal and inland waters.

The plant discharges into inland watercourses that ultimately flow to the Mediterranean Sea, specifically the Tyrrhenian Sea off the northern coast of Sicily. The region's watershed supports diverse aquatic life and is important for local agriculture and tourism. The secondary treatment helps reduce organic pollutants and nutrients, mitigating eutrophication risks in downstream coastal waters.