Casalbuono Impianto Costarelle Wastewater Treatment Plant, Casalbuono, Campania

Casalbuono Impianto Costarelle is a municipal wastewater treatment plant located in Casalbuono, a town in the province of Salerno, Campania, Italy. The plant serves a population of approximately 2,000 residents, making it a small-scale facility within the region's wastewater infrastructure. It operates under Italy's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which sets standards for collection and treatment. The plant provides secondary treatment, a biological process that significantly reduces organic matter and suspended solids. With a designed capacity of 2,000 cubic meters per day and a discharge volume of about 396 cubic meters per day, the facility operates well within its capacity. Secondary treatment is the minimum required for discharges into freshwater bodies under the EU directive for agglomerations of this size. The treated effluent is discharged into local watercourses that drain into the Tyrrhenian Sea via the Sele River basin. This region is ecologically sensitive, supporting diverse aquatic life and agricultural activities downstream. Proper treatment helps protect water quality in the Mediterranean coastal zone.

The plant's discharge enters small streams that flow into the Sele River, which empties into the Tyrrhenian Sea near the Gulf of Salerno. This coastal area supports marine biodiversity and is important for local fisheries and tourism. The secondary treatment process reduces nutrient loads, helping to prevent eutrophication in the receiving waters and maintaining ecological balance in the downstream environment.